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Spirit remains stationary on the west side of Home Plate in the location called "Troy". The rover continues to be busy with an ambitious observation campaign employing both remote sensing and in-situ (contact) science with the robotic arm (instrument deployment device, IDD).
The soil disturbed by the rover's embedding has been the subject of extensive science investigation. Five out of the past seven sols have involved using the instruments on the end of the robotic arm to collect images and composition spectra of five distinct targets. Images from the panoramic camera (Pancam) and spectra from the miniature thermal emission spectrometer (Mini-TES) have also been collected. Extensive nighttime observations have been planned to make use of the abundant energy the rover has right now.
At JPL, preparations are continuing for ground testing with the surface system testbed (SSTB) rover. A special test form has been constructed to hold the new soil simulant that will recreate Spirit's martian terrain. The new simulant has been validated with single-wheel "shoebox" testing by the SSTB rover. Large quantities of simulant ingredients have been ordered and are expected within days.
As of Sol 1939 (June 17, 2009), Spirit's solar array energy production is at 853 watt-hours, with atmospheric opacity (tau) of 0.486 and a dust factor of 0.760. Total odometry remains at 7,729.93 meters (4.80 miles).
sol 1716-1722, October 30 - November 06, 2008: Still Trying to Drive Uphill
Spirit has been trying to drive back up the slope toward the top of "Home Plate" to achieve a more favorable tilt of the solar panels toward the Sun as it moves higher in the sky. Spirit at first made promising progress on sols 1709 (Oct. 23, 2008) and 1713 (Oct. 27, 2008). Subsequent drives have not been as successful. Spirit began veering to the rover's right, which resulted in the right front wheel getting close to slipping off the top of Home Plate and onto the slope. The right front wheel is the one that no longer drives, so if it moves onto the slope it could be difficult to get it back on top of Home Plate.
Fortunately, rover planners have a seemingly bottomless bag of tricks and they continue to try different strategies to make progress up the slope. If necessary, they can direct the rover to drive downslope and take an alternate route back up Home Plate. They can save time if Spirit can make it up the slope from the rover's present location.
Spirit is also preparing for solar conjunction. This is a period of approximately two weeks, beginning November 29, when the Sun will be between Earth and Mars, preventing communication. Preparations include making sure that Spirit's battery is charged and that Spirit has sufficient computer memory available to store data collected during conjunction until it can be sent to Earth.
Spirit is healthy, with all subsystems performing as expected as of the latest transmission from NASA's Odyssey orbiter on sol 1722 (Nov. 6, 2008). Energy from Spirit's solar arrays has been averaging 230 watt-hours (equivalent to the amount of energy needed to light a 100-watt bulb for about 2 hours and 20 minutes).
Sol-by-sol summary
In addition to measuring dust-related changes in atmospheric clarity each day with the panoramic camera, Spirit completed the following activities:
Sol 1716 (Oct. 30, 2008): Spirit checked for drift (changes with time) in the miniature thermal emission spectrometer and completed a mini-survey of the sky and ground with the instrument. Spirit resumed inching uphill. After the drive, Spirit took a single-frame image with the navigation camera as well as images with the hazard-avoidance cameras.
Sol 1717: Spirit checked for drift (changes with time) in the miniature thermal emission spectrometer and completed a mini-survey of the sky and ground with the instrument. The rover recharged the batteries.
Sol 1718: Spirit checked for drift (changes with time) in the miniature thermal emission spectrometer and completed a mini-survey of the sky and ground with the instrument. Spirit continued inching uphill and, after the drive, acquired images with the navigation and hazard-avoidance cameras.
Sol 1719: Spirit checked for drift (changes with time) in the miniature thermal emission spectrometer and completed a mini-survey of the sky and ground with the instrument. The rover made observations of the spectrometer's calibration target and recharged the batteries.
Sol 1720: Spirit checked for drift (changes with time) in the miniature thermal emission spectrometer and completed a mini-survey of the sky and ground with the instrument. The rover acquired four, time-lapse movie frames in search of clouds with the navigation camera and took spot images of the sky for calibration purposes with the panoramic cameras. Spirit completed a "quick fine attitude" adjustment to determine the rover's precise position relative to the Sun. Spirit acquired images with the rear and front hazard-avoidance cameras and used visual odometry to track the rover's actual position based on the surface imprints made by its wheels.
Sol 1721: Spirit continued trying to inch upslope. After stopping, Spirit acquired a single-frame image with the navigation camera as well as images with the hazard-avoidance cameras.
Sol 1722 (Nov. 6, 2008): Spirit checked for drift (changes with time) in the miniature thermal emission spectrometer, completed a mini-survey of the sky and ground with the instrument, and recharged the batteries.
Odometry:
As of sol 1721 (Nov. 4, 2008), Spirit's total odometry was 7,528.56 meters (4.68 miles).
sol 1709-1715, October 23-29, 2008: Spirit Begins Driving Uphill
With the Sun moving higher in the sky, Spirit's solar panels must move in the same direction to maximize their exposure to sunlight. To achieve optimal solar input, the panels still must tilt to the north, but not as steeply as before. To change the tilt, rover drivers have begun moving Spirit back upslope toward the top of "Home Plate." Their goal is to reduce the rover's northerly tilt from 30 degrees to 20 degrees.
The change in tilt is vital, as Spirit is seeing the lowest energy levels of the mission. On Martian day, or sol, 1713 (Oct. 27, 2008), solar-array energy dropped to 207 watt-hours (that's enough energy to light a 100-watt bulb for slightly longer than two hours). The drop in energy was partly due to an increase in atmospheric dust believed to be related to distant dust storm activity. The same day, dust-related loss of visibility, known as Tau, reached a high of 0.69 before dropping to 0.60 on sol 1715 (Oct. 29, 2008).
Because of the limited solar energy, the energy used for driving comes, in part, from the rover's batteries. As solar energy improves, Spirit will have to dip less into the batteries for driving. Fortunately, temperatures are warmer now than in the depths of winter. As a result, the dip in battery reserves is not nearly as great as it would have been if Spirit also required more battery power for heating.
So far, rover drivers are pleased with Spirit's progress. The rover completed three upslope drives to achieve a northerly tilt of 21.8 degrees. Rover operators hope that a couple more budges will give Spirit a northward tilt of 20 degrees.
Eventually, if Spirit can drive all the way back on top of Home Plate, the rover will save a significant amount of time while heading out on the next science campaign. If necessary, Spirit still has the option of driving downslope.
Spirit is healthy, with all subsystems performing as expected as of sol 1715 (Oct. 29, 2008).
Sol-by-sol summary
In addition to measuring dust-related changes in atmospheric clarity each day with the panoramic camera and relaying data to Earth each evening via NASA's Odyssey orbiter, Spirit completed the following activities:
Sol 1709 (Oct. 23, 2008): Spirit checked for drift (changes with time) in the miniature thermal emission spectrometer and surveyed the sky and ground with the instrument. Spirit then began inching uphill, and after the drive, took a single-frame image to document progress with the navigation camera.
Sol 1710: Spirit surveyed the horizon with the panoramic camera, drove, and acquired images with the hazard-avoidance cameras as well as a quarter-frame image of the spacecraft deck with the panoramic camera.
Sol 1711: Spirit checked for drift (changes with time) in the miniature thermal emission spectrometer and completed a mini-survey of the sky and ground with the instrument.
Sol 1712: Spirit monitored dust on the panoramic-camera mast assembly and recharged the batteries..
Sol 1713: Spirit checked for drift (changes with time) in the miniature thermal emission spectrometer and completed a mini-survey of the sky and ground with the instrument. Spirit drove a bit farther upslope.
Sol 1714: Spirit acquired a single-frame, post-drive image with the navigation camera as well as images with the hazard-avoidance cameras.
Sol 1715 (Oct. 29, 2008): Spirit checked for drift (changes with time) in the miniature thermal emission spectrometer and completed a mini-survey of the sky and ground with the instrument. The rover then calibrated the spectrometer and began inching upslope again. After the drive, Spirit took a single-frame image with the navigation camera as well as images with the hazard avoidance cameras.
Odometry
As of sol 1715 (Oct. 29, 2008), Spirit's total odometry remained at 7,528.42 meters (4.68 miles).
sol 1702-1708, October 16-22, 2008: Mars Rover Gets Ready to Move
At Spirit's winter outpost on Mars, the atmosphere has been like the sky on many a clear day in Los Angeles. Smog is not noticeable and details are visible in the surrounding hills, though not with sparkling clarity.
For Spirit, the degree of clarity is especially important because it affects the rover's solar power levels. Lately, the rover has been on a "data diet" of limited atmospheric observations, each one typically generating less than a megabit of data.
One exception during the past week was a 5-by-1 mosaic of images that Spirit acquired to provide a wide-angle view of the rover's winter surroundings. This big-picture view will serve as a guide for putting together the many individual frames of the full-color, "Bonestell panorama" so they fit like the pieces of a jigsaw puzzle.
Spirit's top priority has been the transfer of data from the rover's flash memory files to Earth. Even with reduced activity, the downlink has been slow. When Spirit resumes driving as planned on sol 1709 (Oct. 23, 2008), these downlinks will become even more challenging.
A week ago, dust-related atmospheric murkiness, known as Tau, increased to 0.45. Since then, atmospheric clarity, solar power levels, and dust accumulation have remained steady. Energy from the solar arrays is about 236 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). The dust factor is about 0.33, meaning that only about one-third of sunlight reaching the solar arrays actually penetrates the coating of dust to generate electricity.
On Martian day, or sol, 1700 (Oct. 14, 2008), Spirit checked and adjusted the rover's measurements of Tau. Changes in Tau and the dust factor account for changes in solar energy production. In this instance, the recalibration raised Tau by 0.1 (meaning atmospheric dust levels worsened) and lowered the dust factor by 1 percent (meaning solar penetration was better than engineers thought). At the same time, an actual increase in atmospheric dust caused Tau to go up 0.05, for a total increase of 0.15. The higher dust levels drove down energy production by 18 to 20 watt-hours, compared to dust levels a couple of weeks ago.
The recalibration of Tau measurements is essential because it helps scientists measure changing amounts of dust on the camera lenses. Like drivers watching the road ahead, they need to know if the view is murky because the window is dirty or the atmosphere is hazy. To figure this out on Mars, they tell Spirit to measure Tau near noon when the Sun is overhead and again near sunset when the Sun is low in the sky. They also duplicate the measurements using both the panoramic and navigation cameras.
In preparation for the first roll of the wheels since hunkering down for the winter, Spirit stowed the robotic arm beneath the spacecraft deck. Plans call for the rover to try to climb back up onto "Home Plate" next week. Spirit will drive just far enough to change the northward tilt of the solar panels from 30 degrees to about 20 degrees. The change in position will keep the solar panels pointed toward the Sun. Should the rover be unable to climb the slope, Spirit will drive downhill onto flatter ground.
Spirit remains healthy, with all subsystems performing as expected as of sol 1708 (Oct. 22, 2008).
Sol-by-sol summary
In addition to measuring dust-related changes in atmospheric clarity each day with the panoramic camera and relaying data to Earth each evening via NASA's Odyssey orbiter, Spirit completed the following activities:
Sol 1702 (Oct. 16, 2008): Spirit checked for drift (changes with time) in the miniature thermal emission spectrometer and completed a mini-survey of the sky and ground with the instrument.
Sol 1703: Spirit checked for drift (changes with time) in the miniature thermal emission spectrometer and completed a mini-survey of the sky and ground with the instrument.
Sol 1704: Spirit recharged the batteries.
Sol 1705: Spirit acquired a 5-by-1 mosaic of images to provide a wide-angle, big-picture view of the Bonestell panorama.
Sol 1706: Spirit recharged the batteries.
Sol 1707: Spirit checked for drift (changes with time) in the miniature thermal emission spectrometer and completed a mini-survey of the sky and ground with the instrument. The rover calibrated the miniature thermal emission spectrometer. Spirit stowed the robotic arm and its science instruments in preparation for the rover's first post-winter drive.
Sol 1708 (Oct. 22, 2008): Spirit took spot images of the sky for calibration purposes.
Odometry
As of sol 1708 (Oct. 22, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1695-1701, October 09-15, 2008: Getting Ready to Make the Next Move
In recent weeks, increasing solar power has enabled Spirit to complete more science activities. Spirit has finished the 360-degree, full-color view of its winter surroundings, known as the "Bonestell panorama," and acquired extra frames at super resolution to enhance details in the imagery. The rover also has documented seasonal changes in the atmosphere by measuring argon gas with the alpha-particle X-ray spectrometer.
The tradeoff has been that by funneling most available power into science activities, Spirit has not had much power for sending data to Earth. That is about to change, because Spirit's on-board memory is nearly full. Instead of sending data only every fourth day, Spirit will begin relaying data every day to NASA's Odyssey orbiter for transmission to Earth.
Rover operators will use the data to plan Spirit's first, post-winter drive to adjust the rover's position to keep the solar panels facing the Sun. The move will put the rover in optimum position before solar conjunction, when Earth and Mars will be on opposite sides of the Sun and communication will not be possible. Solar conjunction will take place on Martian days, or sols, 1745-1760 (Nov. 29-Dec. 15, 2008).
Meanwhile, Spirit is healthy, with all subsystems performing as expected as of sol 1700 (Oct. 14, 2008). Solar-array energy has been 242 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). After weeks of remarkably clear skies, atmospheric opacity or tau, a measure of the decrease in sunlight caused by atmospheric dust, has risen slightly to 0.294. Atmospheric dust levels remain low, but are beginning to trend upward and affect solar power levels. This increase is expected, as it has occurred at this time of year in each of the previous three Martian years.
The dust factor -- the percentage of light penetrating dust on Spirit's solar arrays -- has remained steady. Only 32 percent of the sunlight reaching the arrays penetrates the dust to generate electricity.
Sol-by-sol summary
In addition to making daily measurements of the amount of atmospheric dust preventing sunlight from reaching the rover's solar arrays, Spirit completed the following activities:
Sol 1695 (Oct. 9, 2008): Spirit checked for drift (changes with time) in the miniature thermal emission spectrometer, surveyed the sky and ground with the instrument, did survey work with the panoramic camera, and surveyed a surface target dubbed "Jules Verne" with the miniature thermal emission spectrometer.
Sol 1696: Spirit surveyed the sky and ground with the miniature thermal emission spectrometer and made some finishing touches to the lower edge of the full-color, 360-degree view of the rover's winter surroundings by acquiring 3 panels of images known as "Bonestell lower tiers" 1, 2, and 3.
Sol 1697: Spirit used the miniature thermal emission spectrometer to survey the sky, the ground, and a target known as "Stapledon." Spirit parked the panoramic camera mast assembly with the panoramic camera pointed below the horizon to minimize dust accumulation.
Sol 1698: Spirit took spot images of the sky for calibration purposes with the panoramic camera and spent much of the day recharging the battery.
Sol 1699: Spirit surveyed the sky at different elevations as well as the ground with the miniature thermal emission spectrometer and used the panoramic camera to survey the horizon and take thumbnail images of the sky on the rover's right (starboard).
Sol 1700: Spirit surveyed the sky and ground with the miniature thermal emission spectrometer and took spot images of the sky with the panoramic camera. Spirit relayed information from Mars to NASA's Odyssey orbiter for transmission to Earth.
Sol 1701 (Oct. 15, 2008): Spirit surveyed the sky and ground with the miniature thermal emission spectrometer and monitored dust accumulation on the panoramic-camera mast assembly.
Odometry:
As of sol 1700 (Oct. 14, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1690-1694, October 03-08, 2008: Spirit's Memory Is Getting Full
Taking advantage of recent improvements in battery power, Spirit has been rushing to complete top science activities before making a "sun-chasing" adjustment in position in late October. As a result, Spirit's on-board memory has been filling up dramatically as the rover relays data to Earth only once every four Martian days, or sols. In addition, transmissions are challenging because of the rover's position relative to NASA's Odyssey orbiter.
Rover operators plan to increase the flow of information to Earth via Odyssey to about three sessions per week starting on sol 1700 (Oct. 14). Even so, Spirit may need to go on a bit of a science diet over the next few weeks to free up sufficient memory for solar conjunction. That's the period when the Sun is between the Earth and Mars and blocks communications.
Spirit completed work on the 360-degree view of its winter surroundings, known as the "Bonestell panorama." The finished product includes a few select frames taken at super resolution for more detailed study. Spirit also completed another measurement of argon gas in the Martian atmosphere using the alpha-particle X-ray spectrometer. The measurements help scientists characterize seasonal airflows between the Martian poles.
In the past, rover operators have relied on "beeps" from Spirit to know if the rover received and activated command sequences from Earth. The beeps were X-band transmissions sent to Earth over Spirit's low-gain antenna. As power levels sank in the depth of winter, engineers discontinued the beeps to save energy. Recently, they attempted to start sending beeps again, only to find that the signal strength from the low-gain antenna was not great enough for Earth to hear. They decided to send a few beeps from Spirit's dish-shaped, high-gain antenna. Those transmissions were excellent. Rover planners have used them to get a rough estimate of the time drift in the rover's clock during the past nine months or so. The "timing beeps" show that the spacecraft clock has drifted 40 to 50 seconds from "Earth" time.
Spirit is healthy, with all subsystems performing as expected as of sol 1694 (Oct. 8, 2008). Solar-array energy dropped slightly during the past week to 255 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). Tau, a measure of the amount of sunlight blocked by atmospheric dust, increased from 0.134 to 0.209. Historically, dust levels have been elevated at this time of year. Rover operators are keeping close tabs on atmospheric dust because of its potential impact on the rover's low power state.
Sol-by-sol summary
In addition to standard daily activities, which include using the panoramic camera (sometimes more than once) to measure the amount of atmospheric dust preventing sunlight from reaching the solar arrays, checking for drift (changes with time) in the miniature thermal emission spectrometer, and surveying the sky and ground with the instrument, Spirit completed the following activities:
Sol 1690 (Oct. 4, 2008): Spirit acquired column 23, part 3, and column 25, part 3 of the Bonestell panorama, a full-color, 360-degree view of the rover's winter surroundings made with all 13 color filters of the panoramic camera. Before relaying data to Odyssey to be transmitted to Earth, Spirit acquired four movie frames in search of clouds with the navigation camera.
Sol 1691: Spirit acquired column 27, part 3; column 26, part 3; column 24, part 3; and column 22, part 3 of the Bonestell panorama. The rover supplemented the usual, panoramic-camera measurements of atmospheric dust with measurements from the navigation camera. Spirit used the navigation camera to acquire a four-frame movie in search of Martian clouds.
Sol 1692: Spirit acquired column 20, part 3 of the Bonestell panorama as well as half of a super-resolution frame nicknamed "A" and later nicknamed "Hercules Joyner," in honor of a member of the all-black Tuskegee Airmen who served in World War II. The rover acquired a four-frame movie in search of clouds with the navigation camera.
Sol 1693: Spirit surveyed the sky at high Sun with the panoramic camera and acquired half of a super-resolution frame dubbed "General BO Davis," in honor of another Tuskegee Airman. The rover surveyed a target known as "Gernsback" with the miniature thermal emission spectrometer.
Sol 1694 (Oct. 8, 2008): After sending data to Odyssey, Spirit measured atmospheric argon with the alpha-particle X-ray spectrometer.
Odometry:
As of sol 1694 (Oct. 8, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1685-1689, September 28 - October 03, 2008: Spirit and Earth Stick Together
Spirit is poised to begin making more "phone calls" to Earth and engineers are preparing to contact Spirit more frequently as a result of improving solar power input on Mars. Though Spirit's energy levels are still low, they are improving significantly as Martian winter gradually fades into spring. The rover will use some of the energy to let engineers and scientists know how things are going on Mars.
Spirit stays in touch by transmitting data at UHF frequencies to NASA's Odyssey orbiter. Odyssey sends it to Earth. On the other end of the line, engineers send new activity plans to Spirit using X-band transmissions from Earth that go directly to the rover's dish antenna. More frequent communication allows greater operational flexibility as the rover gradually returns to a normal planning schedule and prepares to drive again in mid- to late October.
Spirit's first post-winter drive will be short, just far enough to adjust the rover's position so its solar panels remain tilted toward the Sun as it moves higher in the sky. The goal is to have Spirit in the best possible position before solar conjunction -- the time of year when the Sun passes between Mars and Earth and temporarily prohibits communication.
Meanwhile, Spirit has been working hard to complete the full-color "Bonestell panorama" of the rover's winter surroundings. After a long hiatus caused by power limitations, Spirit resumed making measurements of argon gas in the Martian atmosphere.
Spirit is healthy, with all subsystems performing as expected as of sol 1686 (Sept. 30, 2008). Solar-array energy increased to 262 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). Skies remained clear, with tau, a measure of the amount of sunlight blocked by atmospheric dust, at 0.134. Historically, dust levels at this time of year have been higher. Rover operators are keeping close tabs on atmospheric dust because of its potential impact on the rover's power state.
Sol-by-sol summary
Spirit completed the following activities:
Sol 1685 (Sept. 28, 2008): Spirit listened for communications from Earth with the rover's low-gain antenna, checked for drift -- changes with time -- in the miniature thermal emission spectrometer, surveyed the sky and ground with the instrument, and measured atmospheric opacity caused by dust (tau) with the panoramic camera. Spirit monitored dust accumulation on the panoramic-camera mast assembly and acquired column 22, part 2, and column 24, part 2 of the so-called "Bonestell panorama," a full-color, 360-degree view of the rover's winter surroundings, created with all 13 color filters of the panoramic camera.
Sol 1686: Spirit received new instructions from Earth at X-band frequencies sent to the rover's high-gain antenna and spent three hours measuring argon gas in the Martian atmosphere with the alpha-particle X-ray spectrometer. Spirit relayed data to NASA's Odyssey orbiter to be transmitted to Earth.
Sol 1687: Spirit measured dust-related changes in atmospheric darkness with the panoramic camera and acquired column 23, part 2 and column 25, part 2 of the Bonestell panorama.
Sol 1688: Spirit checked for drift in the miniature thermal emission spectrometer, surveyed the sky and ground with the instrument, and measured atmospheric opacity caused by dust with the panoramic camera. Spirit acquired column 27, part 2 and column 26, part 2 of the Bonestell panorama. The rover supplemented panoramic-camera measurements of atmospheric dust with measurements from the navigation camera and acquired a four-frame movie in search of clouds with the navigation camera.
Sol 1689 (Oct. 3, 2008): Plans called for Spirit to measure dust-related changes in atmospheric darkness with the panoramic camera and acquire column 19, part 3 and column 21, part 3 of the Bonestell panorama. The rover was to assess atmospheric dust levels with the navigation camera and produce a four-frame, time-lapse movie of potential clouds passing overhead.
Odometry:
As of sol 1686 (Sept. 30, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1678-1684, September 21-27, 2008: Spirit Upgrades Calling Plan
Thanks to clear skies and longer Martian days, Spirit can accept three "collect phone calls" a week from Earth instead of two. The rover "pays" for each phone call, which is filled with new activities, with solar energy. As winter fades and sunlight increases with the coming Martian spring, Spirit can stay awake a little longer and accomplish more each day. For example, Spirit is making significant progress toward completing the 360-degree view of the north-facing slope where the rover has spent the past winter.
Spirit continues to phone home less frequently, however, sending news only every fourth Martian day, or sol. That's because the link to NASA's Odyssey orbiter occurs late in the Martian afternoon, when the rover's solar arrays are not generating much energy. The transmission relies almost completely on battery power. Spirit can "bounce back" from the current schedule by replenishing the battery after the Sun rises the next day, but more frequent downlinks remain problematic.
On sol 1680 (Sept. 23, 2008), Spirit completed the interplanetary equivalent of synchronizing watches. The rover sent a five-minute "timing beep" to Earth at X-band frequencies from its high-gain antenna. Antennas on Earth listened for the beep, which couldn't be detected by humans (if humans could hear microwaves, the beep would sound like a five-minute tone). By comparing the expected end time of the beep with the measured end time, rover operators estimated "drift" in Spirit's on-board clock. Currently, Spirit's clock lags by about 45 seconds, well within operational tolerance.
Spirit is healthy, with all subsystems performing as expected as of the report from NASA's Odyssey orbiter on sol 1678 (Sept. 21, 2008). Solar-array energy has increased ever so slightly from 255 watt-hours to 256 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). Skies remain clear, with tau, a measure of the amount of sunlight blocked by atmospheric dust, at 0.14. The dust factor remains steady, with 32.3 percent of incoming sunlight actually penetrating dust on the solar arrays to generate electricity.
Sol-by-sol summary
In addition to taking daily measurements of dust-related changes in atmospheric opacity (tau), Spirit completed the following activities:
Sol 1678 (Sept. 21, 2008): Spirit acquired column 24, part 1 and column 25, part 1 of the so-called "Bonestell panorama," a full-color, 360-degree view of the rover's winter surroundings, using all 13 color filters of the panoramic camera. The rover checked for drift -- changes with time -- in the miniature thermal emission spectrometer and surveyed the sky and ground with the instrument. Spirit relayed data to NASA's Odyssey orbiter to be transmitted to Earth.
Sol 1679: Spirit completed the runout portion of the master sequence of commands and recharged the batteries.
Sol 1680: Spirit sent a five-minute timing beep to Earth to synchronize its clock with Earth's clocks. The rover completed the runout portion of the master sequence of commands and recharged the batteries.
Sol 1681 (Sept. 24, 2008): Spirit switched from planning 2 days a week to planning 3 days a week. The new schedule calls for more "up time" to accommodate more frequent uplinks from Earth and more science activities. Spirit checked for drift in the miniature thermal emission spectrometer and surveyed the sky and ground with the instrument. The rover acquired column 26, part 1; column 27, part 1; and column 18, part 2 of the Bonestell panorama, using all 13 filters of the panoramic camera.
Sol 1682: Spirit checked for drift in the miniature thermal emission spectrometer and surveyed the sky and ground with the instrument. Spirit took spot images of the sky for calibration purposes with the panoramic camera and recharged the batteries.
Sol 1683: Plans called for Spirit to listen for signals from Earth with the rover's low-gain antenna, check for drift in the miniature thermal emission spectrometer, survey the sky and ground with the spectrometer, and calibrate the spectrometer. Spirit was also to acquire column 18, part 3; column 18, part 4; and column 20, part 2 of the Bonestell panorama. The rover was to take color images of the external calibration target with the panoramic camera.
Sol 1684 (Sept. 27, 2008): Plans called for Spirit to check for drift in the miniature thermal emission spectrometer, survey the sky and ground with the instrument, and acquire column 19, part 2, and column 21, part 2 of the Bonestell panorama.
Odometry:
As of sol 1682 (Sept. 25, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
Twitter:
New calling plan: Spirit hears from Earth 3 times a week instead of 2. With longer days, Spirit stays awake longer and takes more pictures!
Spirit doesn't call home as often as her parents would like, but communications are improving. Spirit now takes 3 calls a week from Earth to Mars!
sol 1669-1677, September 12-20, 2008: Warming Up on Mars
With Martian winter on the wane, Spirit is using significantly less energy to stay warm. During the winter solstice, Spirit needed 90 watt-hours to run the heater. Now, the rover uses between 30 and 40 watt-hours. The reduced demand for power, more than the slow increase in solar-array input, has freed up energy for other things. In particular, Spirit has added more images to the 360-degree view of its winter surroundings, known as the "Bonestell panorama." The top tier, one of three tiers needed for the final image mosaic, is almost complete.
Plans called for Spirit to use the miniature thermal emission spectrometer for the first time in several months. The last time the rover used the instrument was on Martian day, or sol, 1558 (May 21, 2008). On sol 1675 (Sept. 18, 2008), Spirit's schedule of activities included calibrating the spectometer and using it to observe the sky and ground. Normally, scientists use the observations to measure temperatures at different heights and create a temperature profile of the ground and atmosphere. In this case, the purpose of the measurements is to verify that the spectrometer is still working after a long, cold period of disuse. The measurements will also enable scientists to estimate the amount of dust on the optics. They may or may not provide a useful temperature profile.
Spirit is healthy and all subsystems are performing as expected as of the most recent report from NASA's Odyssey orbiter on sol 1674 (Sept. 17, 2008). Solar-array energy has inched upward to 255 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). Skies are clearer than last week, with tau, a measure of the amount of sunlight blocked by atmospheric dust, dropping to 0.141.
Sol-by-sol summary
In addition to taking daily measurements of dust-related changes in atmospheric opacity (tau), Spirit completed the following activities:
Sol 1669 (Sept. 12, 2008): Spirit recharged the batteries.
Sol 1670: Spirit received new instructions directly from Earth sent at X-band frequencies to the rover's high-gain antenna. The rover relayed data to NASA's Odyssey orbiter to be transmitted to Earth.
Sol 1671: Spirit acquired column 20, part 1 and column 21, part 1 of the full-color Bonestell panorama, using all 13 color filters of the panoramic camera. The rover took spot images of the sky for calibration purposes with the panoramic camera.
Sol 1672: Spirit recharged the batteries.
Sol 1673: Spirit recharged the batteries.
Sol 1674: Spirit received new instructions from Earth via the rover's high-gain antenna. The rover relayed data to Odyssey to be sent to Earth.
Sol 1675: Plans called for Spirit to acquire column 22, part 1 and column 23, part 1 of the Bonestell panorama and then verify that the miniature thermal emission spectrometer was still functional. This involved warming up the actuator, calibrating the instrument, measuring ground temperature, and measuring atmospheric temperatures at different heights. Plans also called for Spirit to calibrate the panoramic camera by taking images in darkness while the instrument was warm.
Sol 1676: Plans called for Spirit to recharge the batteries.
Sol 1677 (Sept. 20, 2008): Plans called for Spirit to recharge the batteries.
Odometry:
As of sol 1674 (Sept. 17, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1663-1668, September 06-11, 2008: Light Duty for Now
Spirit continues to conserve solar power while performing light science activities during the Martian winter. During the past week, Spirit studied the atmosphere and acquired two frames of the full-color image mosaic known as the "Bonestell panorama."
Spirit is healthy and all subsystems are performing as expected as of the relay of information from NASA's Odyssey orbiter on sol 1666 (Sept. 9, 2008). Solar-array energy and tau -- a measure of atmospheric opacity caused by suspended dust -- are holding steady at 245 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour) and 0.20, respectively.
Sol-by-sol summary
In addition to taking daily measurements of dust-related changes in atmospheric opacity (tau), Spirit completed the following activities:
Sol 1663 (Sept. 6, 2008): Spirit recharged the batteries.
Sol 1664: Spirit acquired column 18 of the Bonestell panorama, using all 13 color filters of the panoramic camera.
Sol 1665: Spirit recharged the batteries.
Sol 1666: Spirit recharged the batteries.
Sol 1667: Spirit received new instructions from Earth via the rover's high-gain antenna and relayed data to the UHF antenna on NASA's Odyssey orbiter to be transmitted to Earth.
Sol 1668 (Sept. 11, 2008): Spirit monitored dust accumulation on the panoramic-camera mast assembly and acquired column 19 of the Bonestell panorama.
Odometry:
As of sol 1666 (Sept. 9, 2008), Spirit's total odometry was 7,528.0 meters (4.7 miles).
sol 1657-1662, August 31-September 05, 2008: Spirit Continues Work on Winter Panorama
Spirit continues to conserve power during the waning Martian winter while performing light science activities. As power permits, Spirit continues to acquire the individual frames of an image mosaic known as the "Bonestell panorama," which will portray a full-color view of the rover's winter outpost.
Spirit is healthy, with all subsystems performing as expected as of the most recent report from Mars sent by NASA's Odyssey orbiter on sol 1658 (Sept. 1, 2008). Solar-array energy had increased slightly from 235 to 245 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). Tau -- a measure of atmospheric opacity caused by suspended dust -- dropped from 0.274 to 0.218, meaning the skies were slightly clearer.
Sol-by-sol summary
In addition to taking daily measurements of dust-related changes in atmospheric opacity (tau), Spirit completed the following activities:
Sol 1657 (Aug. 31, 2008): Spirit acquired column 13, part 1 of the so-called "Bonestell panorama" of the rover's winter surroundings, using all 13 color filters of the panoramic camera.
Sol 1658: Spirit relayed data from Mars to NASA's Odyssey orbiter to be transmitted to Earth.
Sol 1659: Spirit received new instructions from Earth via the rover's high-gain, X-band antenna.
Sol 1660: Spirit recharged the batteries.
Sol 1661: Spirit recharged the batteries.
Sol 1662 (Sept. 5, 2008): Spirit recharged the batteries.
Odometry:
As of sol 1658 (Sept. 1, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1651-1656, August 25-30, 2008: Spirit Still Biding Time -- and Checking the Clock
To adjust for changes, known as "drift," in synchronicity between Spirit's clock and Earth-based clocks, engineers instructed Spirit to send a "timing beep" to Earth on Martian day, or sol, 1652 (Aug. 26, 2008). For a specifically scheduled duration of time, Spirit radiated a signal to Earth over its low-gain antenna. Rover operators listened for the signal, in order to make sure Spirit's clock and Earth clocks were in agreement.
Spirit continues to ride out the Martian winter by doing minimal activities in an attempt to save power. Spirit conducts science observations every three to four Martian days, known as sols. Every four sols, the rover sends data to NASA's Odyssey orbiter for transmission to Earth. Otherwise, Spirit mostly rests and recharges the batteries. This pattern of activity is not likely to change until sunlight on the rover's solar panels consistently generates 250 watt-hours (enough energy to light a 100-watt bulb for 2.5 hours) or more. Engineers do not expect that to happen until approximately mid-October, barring wind-related, dust-cleaning events between now and then.
Spirit remains healthy, with all subsystems performing as expected as of the downlink of information from NASA's Odyssey orbiter on sol 1650 (Aug. 24, 2008). Solar-array energy as of the same sol was 232 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). Tau -- a measure of atmospheric opacity caused by suspended dust -- was 0.274. Spirit is approaching a time of year when the rover has historically seen increased atmospheric dust levels. Given the rover's already low power state, engineers will be on the lookout for dust-related changes in solar power.
Sol-by-sol summary
During the past week, Spirit completed the following activities:
Sol 1651 (Aug. 25, 2008): Spirit measured dust-related changes in atmospheric clarity (tau) with the panoramic camera. Spirit acquired column 17, part 1 of the so-called "Bonestell panorama" of the rover's winter surroundings, using all 13 color filters of the panoramic camera.
Sol 1652: Spirit received new instructions from Earth via the rover's high-gain, X-band antenna and transmitted the requested "timing beep" to Earth.
Sol 1653: Spirit recharged the batteries.
Sol 1654: Spirit measured dust-related changes in atmospheric clarity with the panoramic camera and acquired column 15, part 1 of the full-color Bonestell panorama. Spirit relayed data to NASA's Odyssey orbiter for transmission to Earth.
Sol 1655: Spirit recharged the batteries.
Sol 1656 (Aug. 30, 2008): Plans called for Spirit to receive a new set of instructions from Earth via the rover's high-gain antenna.
Odometry:
As of sol 1654 (Aug. 28, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1643-1650, August 16-24, 2008: Spirit Still Biding Time
Spirit continues to ride out the Martian winter by doing minimal activities to conserve power. The rover completes very light science observations every three to four Martian days, known as sols, and relays data to NASA's Odyssey orbiter to be transmitted to Earth every four sols. Otherwise, Spirit mostly sleeps. This pattern is not likely to change until sunlight on the rover's solar array consistently generates 250 watt-hours or more (enough energy to light a 100-watt bulb for 2.5 hours). Barring dust-cleaning winds, that is not expected to happen before about mid-October.
Spirit remains healthy, with all subsystems performing as expected as of the Odyssey downlink to Earth on sol 1646 (Aug. 19, 2008). Solar-array energy has dropped back to 229 watt-hours after recently reaching the high 230's. This drop is the result of an increase in tau -- a measure of atmospheric opacity caused by suspended dust -- from 0.19 to 0.29. Spirit is approaching a time of year when the rover has historically seen increased atmospheric dust levels. Given the rover's low power state, engineers will be watching this trend very closely.
Sol-by-sol summary
During the past week, Spirit completed the following activities:
Sol 1643 (Aug. 16, 2008): Spirit monitored atmospheric darkness caused by dust with the panoramic camera. Spirit acquired column 15, part 2 of the so-called "Bonestell panorama," using all 13 filters of the panoramic camera.
Sol 1644: Spirit recharged the batteries.
Sol 1645: Spirit recharged the batteries.
Sol 1646: Engineers on Earth transmitted a new plan of activities at X-band frequencies directly to Spirit's high-gain antenna. Spirit relayed data to NASA's Odyssey orbiter for transmission to Earth.
Sol 1647: Spirit monitored atmospheric opacity with the navigation camera and acquired column 17, part 2 of the "Bonestell camera," using all 13 color filters of the panoramic camera.
Sol 1648: Spirit recharged the batteries.
Sol 1649: Plans called for Spirit to continue to rest and recharge the batteries.
Sol 1650 (Aug. 24, 2008): Spirit was to receive a new plan of activities transmitted at X-band frequencies directly to Spirit's high-gain antenna. The rover was scheduled to relay data to NASA's Odyssey orbiter for transmission to Earth.
Odometry:
As of sol 1642 (Aug. 15, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1635-1642, August 08-15, 2008: Spirit Standing By
Though Spirit is using less energy to run heaters as Martian winter slowly gives way to spring, dust on the rover's solar arrays continues to block sunlight. Presently about one-third -- 34 percent -- of sunlight reaching the arrays is penetrating the layer of dust to generate electricity. This is a primary reason why Spirit's third winter on the red planet has been more difficult than the first two.
Energy has been steady, averaging 235 watt-hours daily (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). Tau, a measure of atmospheric dust, and the dust factor, a measure of the amount of dust on the solar arrays, have also been steady at 0.197 and 0.340, respectively. The Tau measurement indicates that 80 to 82 percent of direct sunlight makes it through the atmosphere and reaches the array (the rest is scattered or absorbed, though scattered light also contributes to Spirit's energy).
Currently, Spirit spends one of every four Martian days, or sols, taking science images. The slight energy increase isn't yet sufficient to allow more activity.
Spirit remains healthy and all subsystems are normal as of the latest downlink of information from the Odyssey orbiter on sol 1638 (Aug. 11, 2008).Sol-by-sol summary
In addition to measuring atmospheric dust with the panoramic camera, Spirit completed the following activities:
Sol 1635 (Aug. 8, 2008): Spirit implemented the runout portion of the master sequence of commands already on board the rover, then received new instructions from Earth via the rover's high-gain antenna. The rover recharged the batteries.
Sol 1636: Spirit implemented the runout portion of the master sequence of commands already on board the rover and recharged the batteries.
Sol 1637: Spirit woke up and listened for potential transmissions from Earth at X-band frequencies using the rover's broad-beam, low-gain antenna. Spirit acquired column 13, part 2 of the so-called "Bonestell panorama," using all 13 filters of the panoramic camera.
Sol 1638: Spirit woke up and listened for signals from Earth at X-band frequencies using the low-gain antenna. Spirit completed the runout portion of the master sequence of commands on board the rover and relayed data to NASA's Odyssey orbiter for transmission to Earth.
Sol 1639: Spirit woke up and listened for signals from Earth using the rover's low-gain antenna. Engineers on Earth transmitted a new plan of activities at X-band frequencies to the rover's high-gain antenna. Those plans called for Spirit to spend the day surveying the horizon and monitoring the dune field known as "El Dorado" with the panoramic camera.
Sol 1640: Plans called for Spirit to complete the runout portion of the master sequence of commands on board the rover. Spirit was to wake up and listen for signals from Earth using the low-gain antenna and recharge the batteries. To save energy, Spirit was not directed to measure atmospheric opacity, known as Tau.
Sol 1641: Plans called for Spirit to complete the runout portion of the master sequence of commands on board the rover. Spirit was to wake up and listen for signals from Earth using the low-gain antenna and recharge the batteries. Spirit was not scheduled to measure atmospheric opacity.
Sol 1642 (Aug. 15, 2008): Plans called for Spirit to wake up and listen for signals from Earth using the low-gain antenna. Later, the rover was to relay information to Odyssey about the past four sols of activity.
Odometry:
As of sol 1638 (Aug. 11, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1628-1634, August 01-07, 2008: Waiting Out the Winter
Spirit's battery levels are slowly edging upward, thanks to a slight decrease in atmospheric dust (Tau) and a gradual increase in sunlight as winter gives way to spring.
Early in the week, Spirit spent two Martian days carrying out contingency plans following a temporary delay in data transmission from Earth. Spirit implemented the so-called "runout" portion of an earlier master sequence on sols 1628 and 1629 (Aug. 1-2, 2008). Subsequent relays of new instructions from Earth on sols 1629 and 1632 (Aug. 2 and Aug. 5, 2008) went off without a hitch.
Spirit remains healthy, with all subsystems performing as expected as of sol 1630 (Aug. 3, 2008).
Sol-by-sol summary
In addition to using the panoramic camera to make daily measurements of dust-related changes in atmospheric clarity, Spirit completed the following activities:
Sol 1628 (Aug. 1, 2008): Spirit implemented the runout portion of the master sequence of commands already on board the rover.
Sol 1629: Upon awakening, Spirit continued to implement the runout portion of the master sequence sent earlier. Spirit then received new instructions directly from Earth via the rover's high-gain antenna.
Sol 1630: Spirit acquired column 13 of the "Bonestell panorama" using all 13 color filters of the panoramic camera. The rover relayed fresh data from Mars at UHF radio frequencies to NASA's Odyssey orbiter to be transmitted to Earth.
Sol 1631: Spirit recharged the batteries.
Sol 1632: Spirit received new instructions from Earth via the rover's high-gain antenna.
Sol 1633: Spirit acquired six freeze frames for a time-lapse movie in search of Martian clouds using the navigation camera. The rover took spot images of the sky for calibration purposes with the panoramic camera and monitored dust on the panoramic-camera mast assembly.
Sol 1634 (Aug. 7, 2008): Spirit transmitted fresh data to Odyssey to be relayed to Earth.
Odometry:
As of sol 1634 (Aug. 7, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1621-1627, July 25-31, 2008: With Batteries Charged, Spirit is Ready for More Science
Spirit has fully recovered from a recent rundown in battery power. Energy has improved to levels not seen since sol (Martian day) 1604 (July 7, 2008). The hit in battery energy was primarily the result of data transmissions taking place later in the day, when less solar energy was available.
During the past week, rover planners eliminated the late communications sessions. Spirit is not scheduled to have another one until sol 1636 (Aug. 9, 2008). To mitigate the impact that one will have on power, rover planners plan to shorten the duration of data transmission from 20 minutes to only 10 minutes. This will allow sufficient time to get new instructions on board the rover while minimizing battery drain.
A transmitter problem thwarted data transmission on sol 1625 (July 29, 2008). The uplink from Earth was to have loaded activity plans and maintenance instructions for sols 1626, 1627, 1628 and 1629 (July 30-Aug. 2, 2008). The sequences already on board Spirit were designed with built-in contingency plans to handle just such an event. As a result, while Spirit continues the "runout" portion of the earlier master sequence, rover operators will send a new set of commands for sols 1630, 1631 and 1632 (Aug. 3-5, 2008) on sol 1629 (Aug. 2, 2008).
Spirit remains healthy, with all subsystems performing as expected as of sol 1626.
Sol-by-sol summary
In addition to using the panoramic camera to make daily measurements of dust-related changes in visibility, Spirit completed the following activities:
Sol 1621 (July 25, 2008): Spirit recharged the batteries.
Sol 1622: Spirit received instructions from Earth via the rover's high-gain antenna and relayed data to NASA's Odyssey orbiter via the rover's UHF antenna.
Sol 1623: Spirit acquired images of sand formations with the rear hazard-avoidance and navigation cameras. The rover took six, time-lapse, movie frames in search of clouds with the navigation camera, as well as images of the sky (called "sky flats") for calibration purposes.
Sol 1624: Spirit recharged the batteries.
Sol 1625: Spirit took spot images of the sky for calibration purposes with the panoramic camera and acquired movie frames in search of clouds with the navigation camera.
Sol 1626: Spirit completed a horizon survey with the panoramic camera and relayed data to Odyssey for transmission to Earth.
Sol 1627 (July 31, 2008): Spirit recharged the batteries.
Odometry:
As of sol 1626 (July 30, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1615-1620, July 19-24, 2008: Time to Recharge the Batteries
Spirit is recovering from a recent rundown in battery power. Over the last two weeks, Spirit's battery levels have steadily dropped by about 18 percent. The decrease appears to be a result of transmitting data to Earth later in the day and staying awake longer to accommodate extra science activities.
When Spirit sends transmissions late in the day, there's not enough sunlight left to recharge the batteries. As a consequence, each late uplink has contributed to an energy deficit.
Barring sudden changes in Martian temperature or atmospheric dust levels, engineers expect it may take as long as two weeks to recharge the batteries enough to resume work on the Bonestell panorama and other science activities.
Spirit remains healthy and all subsystems are operating as expected as of Martian day, or sol, 1618 (July 22, 2008).
Sol-by-sol summary
In addition to daily, panoramic-camera measurements of atmospheric opacity caused by dust, Spirit completed the following activities:
Sol 1615 (July 19, 2008): Spirit received new instructions from Earth via the rover's high-gain antenna.
Sol 1616: Spirit monitored dust accumulation on the panoramic-camera mast assembly.
Sol 1617: Spirit recharged the batteries.
Sol 1618: Spirit received instructions from Earth over the rover's high-gain antenna and relayed data to Earth via NASA's Mars Odyssey orbiter.
Sol 1619: Spirit took spot images of the sky for calibration purposes with the panoramic camera and acquired movie frames in search of clouds with the navigation camera.
Sol 1620 (July 24, 2008): Spirit recharged the batteries.
Odometry:
As of sol 1618 (July 22, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1608-1614, July 11-18, 2008: A Juggling Act
Winter planning for Spirit requires human operators to perform a complex juggling act to maintain overall rover health. They must manage engineering activities, such as receiving science and engineering data from Mars and sending new operation plans from Earth, as well as try to fit in science observations when possible. But they must also give the rover sufficient downtime between these activities to recharge the batteries. In recent months, the team's juggling skills have continued to improve.
Meanwhile, Mars has been helping out with steady temperatures and low levels of atmospheric dust, providing stability when it comes to allocating energy for heating and predicting the amount of sunlight reaching the rover's solar panels to generate electricity. Solar energy has been steady between 225 watt-hours to 230 watt-hours, of which about 65 to 75 watt-hours is required for heating the batteries and the miniature thermal emission spectrometer.
The overall state of charge on the battery has dropped slightly as a result of the timing of engineering and science activities. To restore the state of charge, the rover team will be making adjustments in upcoming plans.
Spirit is healthy and all subsystems are performing as expected as of sol 1610 (July 13, 2008).
Sol-by-sol summary
During the past week, in addition to making daily measurements of atmospheric opacity caused by dust with the panoramic camera, Spirit completed the following activities:
Sol 1608 (July 11, 2008): Spirit received new instructions from Earth via the rover's high-gain antenna.
Sol 1609: Spirit acquired column 17, part 3 of the so-called "Bonestell panorama" using all 13 color filters of the panoramic camera. The rover acquired six, time-lapse, movie frames in search of clouds with the navigation camera.
Sol 1610: Spirit relayed science and engineering data to NASA's Odyssey orbiter for transmission to Earth.
Sol 1611: Spirit received instructions from Earth over the rover's high-gain antenna and sent a timing beep to Earth at X-band frequencies.
Sol 1612: Spirit acquired column 15, part 3 of the full-color Bonestell panorama.
Sol 1613: Spirit recharged the battery.
Sol 1614 (July 18, 2008): Spirit relayed science and engineering data to Odyssey for transmission to Earth.
Odometry:
As of sol 1610 (July 13, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1601-1607, July 04-10, 2008: Solar Energy Evens Out
A week after the winter solstice, NASA's Mars rover Spirit is experiencing stable solar energy levels of between 225 watt-hours and 230 watt-hours. (One hundred watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). Spirit continues to perform light science activities every three to four Martian days, or sols. Science activities this week included acquiring additional frames of the so-called "Bonestell panorama" of Spirit's overwintering locale.
The rover continues to relay data to NASA's Odyssey orbiter every four sols. The reduced level of activity has allowed Spirit to maintain a healthy battery charge despite the low level of solar energy input.
Spirit is healthy and all subsystems were performing as expected as of the downlink of fresh data from Odyssey on Sol 1606 (July 9, 2008).
Sol-by-sol summary
During the past week, Spirit completed the following activities:
Sol 1601 (July 4, 2008): Spirit assessed atmospheric dust levels based on the darkness of the sky with the panoramic camera.
Sol 1602: Spirit assessed atmospheric dust, monitored the dune field known as "El Dorado," and took spot images of the sky for calibration purposes with the panoramic camera. The rover relayed data to Odyssey for transmission to Earth.
Sol 1603: Spirit recharged the battery and measured atmospheric dust opacity with the panoramic camera.
Sol 1604: Spirit received a new activity plan from Earth via the rover's high-gain antenna and assessed atmospheric dust levels with the panoramic camera.
Sol 1605: Spirit again gauged atmospheric dust levels and also surveyed the horizon with the panoramic camera. The rover acquired Column 16, Part 4 of the Bonestell panorama, using all 13 color filters of the panoramic camera.
Sol 1606: Spirit assessed atmospheric dust with the panoramic camera and sent fresh data to Odyssey for transmision to Earth.
Sol 1607 (July 10, 2008): Spirit recharged the battery and measured atmospheric dust with the panoramic camera.
Odometry:
As of sol 1606 (July 9, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1594-1600, June 27-July 03, 2008: Biding Time
Spirit continues to ride out the Martian winter by doing minimal activities to conserve power. The rover conducts very light science activities every three to four Martian days, or sols, and relays data to NASA's Odyssey orbiter for transmission to Earth every 4 sols. The rest of the time, Spirit mostly sleeps.
As it has been some time since Spirit's operators were able to synchronize the spacecraft clock to Earth time, they wished to determine how far the spacecraft clock had drifted (how much it had changed over time). Synchronization of the clock is a process that requires a power-intensive, two-way, X-band communications link. When the power situation allowed it, they decided to perform an X-band "beep" (a five-minute, low-gain communication session) to estimate the amount of drift. The transmission of plans to do so on sol 1594 (June 27, 2008) were not detected by the ground station. Engineers hoped to make another attempt on sol 1604 (July 7, 2008).
Spirit is healthy and all subsystems were performing as expected as of the Odyssey downlink on sol 1598 (July 1, 2008). Solar-array energy has been steady within the range of 225 watt-hours to 230 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour).
Sol-by-sol summary
During the past week, Spirit completed the following activities:
Sol 1594 (June 27, 2008): Plans called for Spirit to perform a five-minute "beep" at X-band frequencies after relaying data to Earth via the Odyssey orbiter.
Sol 1595: Spirit recharged the battery and measured atmospheric dust opacity, known as Tau, using the panoramic camera.
Sol 1596: Spirit recharged the battery and measured atmospheric dust opacity with the panoramic camera.
Sol 1597: Spirit recharged the battery and measured atmospheric dust opacity with the panoramic camera.
Sol 1598: Spirit received new instructions from Earth via the rover's high-gain, X-band antenna and relayed data to Odyssey at UHF frequencies for transmission of the latest Martian data to Earth. The rover measured atmospheric darkness caused by suspended dust particles with the panoramic camera.
Sol 1599: Spirit conducted light remote sensing.
Sol 1600 (July 3, 2008): Spirit recharged the battery and again measured atmospheric dust with the panoramic camera.
Odometry:
As of sol 1598 (July 1, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1587-1594, June 20-27, 2008: Here Comes the Sun
With this week's passage of the longest night and shortest day of the year, also known as the winter solstice, Spirit's solar power levels should slowly but steadily increase. The winter solstice occurred on Martian day, or sol, 1591 (June 24, 2008, Pacific time).
In fact, Spirit's solar array energy and battery state of charge have already improved in recent days to the point where rover operators have begun adding some planning features back into the rover's schedule. The first change, adopted as of sol 1592 (June 25, 2008), was to return to a planning schedule covering every 3 or 4 sols. The plans themselves remain quite spartan at this time. In particular, rover operators are still planning to have Spirit relay data to Earth only every 4 sols. To do this, the rover sends data to NASA's Odyssey spacecraft, in orbit above Mars. To save power, engineers are keeping the data relays short in duration. Spirit has begun measuring dust-related atmospheric darkness every sol instead of every other sol.
Because it has been some time since engineers have been able to synchronize the spacecraft clock to Earth time, they decided to determine how much the clock had "drifted" -- that is, changed with time. To do this usually requires a power-intensive, two-way, X-Band communication session. This time, to save energy, they decided to perform an X-band "beep," a five-minute communication session using the rover's low-gain antenna, on sol 1594 (June 27, 2008). Accuracy will not be as good, but they expect to get an estimate of drift that is accurate to within about a minute.
Spirit is healthy and all subsystems are performing as expected as of the Odyssey downlink on sol 1590 (June 23, 2008). Solar array energy has been steady at 230 watt-hours, enough energy to light a 100-watt bulb for 2.5 hours.
Sol-by-sol summary
During the past week, Spirit completed the following activities:
Sol 1587 (June 20, 2008): Spirit recharged the battery.
Sol 1588: Spirit recharged the battery and received new instructions direct from Earth via the rover's high-gain dish antenna. Spirit measured atmospheric dust opacity, known as Tau, with the panoramic camera.
Sol 1589: Spirit recharged the battery.
Sol 1590: Spirit recharged the battery, measured atmospheric opacity caused by dust with the panoramic camera, and relayed data to Odyssey for transmission to Earth.
Sol 1591: Spirit recharged the battery and received a backup relay of commands from Earth via the rover's high-gain antenna.
Sol 1592: Spirit recharged the battery and conducted light remote sensing.
Sol 1593: Spirit recharged the battery.
Sol 1594 (June 27, 2008): Plans called for Spirit to send data to Odyssey for relay to Earth and transmit a five-minute signal to Earth to allow spacecraft operators to estimate drift in the spacecraft clock.
Odometry
As of sol 1586 (June 19, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1580-1586, June 13-19, 2008: Battery Power on the Rise
Spirit's battery is recharging nicely now that rover planners have reduced the frequency of communications to and from the rover during the darkest days of Martian winter. Most measures of battery health are showing an increase of about 2 amp-hours in the battery state of charge (an amp-hour is equivalent to the amount of charge flowing for one hour from a current of 1 amp). The minimum state of charge has improved from 10.92 amp-hours to 12.97 amp-hours, the maximum from 16.77 amp-hours to 18.17 amp-hours, which is fairly close to the battery's full capacity of 19.5 amp-hours.
Because battery energy increased sufficiently, the team added 12 minutes of remote sensing science to Spirit's to-do list for Sol 1586 (June 19, 2008). Spirit was to monitor atmospheric dust with the panoramic camera as well as dust on the panoramic-camera mast assembly and acquire seven, time-lapse movie frames in search of clouds with the navigation camera. Engineers anticipate that the additional activities will have no significant effect on the battery's state of charge.
Skies remain remarkably clear. Solar array energy is up slightly, averaging 229 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). Atmospheric darkness caused by dust (known as Tau) increased by an insignificant amount, going from an average of 0.193 the previous week to 0.205 this week. The dust factor, the fraction of sunlight hitting the arrays that penetrates the dust layer, also rose insignificantly, from 0.349 to 0.352.
Rover planners are generating new activity plans for Spirit only once a week to minimize uplink time and therefore the length of time the rover must stay awake. Spirit relays data to Earth only every fourth sol to minimize battery usage.
In addition to estimating the amount of scattering and absorption of sunlight by atmospheric dust, Spirit received one transmission of new instructions direct from Earth to the rover's high-gain antenna on Sol 1581 (June 14, 2008). Spirit sent two transmissions of data to Earth via Odyssey on sols 1582 and 1586 (June 15 and June 19, 2008). Data from the sol 1582 downlink showed that the backup uplink on sol 1584 (June 17, 2008) was not needed and the communications link was shortened to save energy.
Spirit remains healthy and all subsystems were performing as expected as of the downlink to Earth via NASA's Odyssey Mars orbiter on sol (Martian day) 1582 (June 15, 2008).
Sol-by-sol summary
During the past week, Spirit completed the following activities:
Sol 1580 (June 13, 2008): Spirit recharged the battery and measured atmospheric opacity caused by dust (Tau) using the panoramic camera.
Sol 1581: Spirit recharged the battery and received new instructions direct from Earth to the rover's high-gain dish antenna.
Sol 1582: Spirit soaked up the sunlight to recharge the battery, assessed atmospheric darkness caused by dust particles with the panoramic camera, and sent data to NASA's Odyssey orbiter for transmission to Earth.
Sol 1583: Spirit recharged the battery.
Sol 1584: Spirit recharged the battery, surveyed atmospheric dust with the panoramic camera, and received new commands from Earth over the rover's high-gain antenna.
Sol 1585: Spirit recharged the battery.
Sol 1586 (June 19, 2008): Plans called for Spirit to recharge the battery, conducted remote sensing, and send data to Odyssey for relay to Earth.
Odometry
As of sol 1578 (June 11, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1574-1579, June 06-12, 2008: New Tricks for an Old Rover
To conserve energy and protect one of the on-board spectrometers, spacecraft operators have established the first major change to planning for the Mars Exploration Rover mission since the end of the primary mission, which lasted for 90 days in early 2004.
Spirit's scientists have declared that their highest priority for the winter is preserving the miniature thermal emission spectrometer, an instrument that identifies minerals in rocks from a distance. To do this, the rover heats the instrument overnight and into the morning of every sol. These heaters have been running longer as winter temperatures have dropped and are now averaging about 55 watt-hours per sol.
Heating for Spirit's batteries has increased as well and is now averaging 29 watt-hours per sol. Together, the two heaters account for 84 watt-hours or about 37 percent of Spirit's total energy usage. Everything else, including on-board computers and memories, radios, cameras, sensors and actuators, gets by on about 140 watt-hours -- enough energy to run a microwave oven for a scant 7 minutes.
In response, rover operators have further reduced Spirit's activity levels. The rover now transmits data to Odyssey to be relayed to Earth only every fourth sol. Instead of spending 20 minutes each sol using the rover's high-gain antenna to listen for new instructions from Earth, Spirit spends five minutes listening for instructions using the low-gain antenna on all but two sols per week.
Rover operators create new activity plans once a week, on Fridays, that cover seven sols at a time. Because Spirit isn't engaged in activities that require rover operators to have new images or other data for planning, the rover does not have to relay data to Odyssey just before a planning day. Despite changes to multiple procedures and software tools, the transition has been remarkably smooth.
For the time being, Spirit is basically just hanging out, charging the batteries.
Recent Events
Initially, the uplink team deleted virtually all science activities except for tau measurements of atmospheric dust. They then limited transmission of rover data to NASA's Odyssey orbiter, which consumes about 30 watt-hours, to every other sol. Still, the batteries continued to use more energy than they could replenish.
Prior to this change, Spirit received new plans three times a week and listened for new instructions for 20 minutes every sol. The 20-minute, high-gain-antenna communication window was costing the rover a lot of unnecessary awake time. On the other hand, engineers on Earth needed Spirit to be awake for at least 15 minutes every sol. By changing some of the unneeded 20-minute communication windows to shorter, five-minute, low-gain-antenna communication windows, and by having the windows overlap with the required awake time, Spirit's operators have shortened the overall awake time from 39 minutes to 16 minutes and saved another 15 watt-hours per sol.
Engineers have also gotten more strategic about how they communicate with Spirit. They send a new activity plan to Spirit every week (after the Friday planning session). Because Odyssey downlinks happen only every fourth sol, they can't guarantee they'll have a communication from Odyssey showing whether an uplink actually made it to the rover. So they send the same activity plan a second time. If the first uplink is successful, software on the rover automatically changes the second, high-gain communication window to a five-minute, low-gain window, saving 15 watt-hours. When this occurs, the second uplink fails and flight software generates a bunch of warnings, known as event reports. The warnings tell engineers that the plan is on board. If the first uplink fails, the instructions to change the second uplink window don't take place.
Why do engineers do the planning on Fridays? A new schedule of communication opportunities, called a "strategic load," goes into effect every other Friday. Rover operators plan activities on Friday so they can include the strategic load in the uplink.
The new strategy is working. Battery states of charge are up about two amp-hours (an amp-hour is a measure of electrical current flowing for one hour) above the rather scary levels of two weeks ago and other indicators of battery health are similarly improving. Spirit now has some margin of protection against further increases in heating power or unpleasant changes in the Martian environment. One concern is the possibility that thin, water-ice clouds could form overhead during the Martian winter. Such clouds are nearly invisible without image enhancement but they're thick enough to noticeably lower solar array energy. Fortunately, there's been no evidence of water-ice clouds so far.
Turning the Corner
The Martian winter solstice will be on June 25, 2008 (sol 1591). During the winter solstice, the Sun is as low in the sky as it ever gets. From there, it will rise higher each sol until the summer solstice in May 2009. For Spirit, solar power levels are expected to increase in a few weeks. Unlike Earth, where the coldest temperatures arrive 4-6 weeks after the solstice, Martian temperatures will begin to rise again almost immediately -- but slowly, very, very slowly.
With little dust overhead, Spirit is seeing very little additional dust settling out on the rover's solar arrays. The dust factor, a measure of the proportion of sunlight penetrating the coating of dust on the solar arrays, has remained almost unchanged at 0.349 (meaning that 34.9 percent of the sunlight, direct and scattered, that reaches the arrays penetrates the dust layer to generate electricity).
Energy has been steady, averaging about 226 watt-hours each Martian day, or sol, and varying by only a couple of watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). This is due in large part to a clear and stable atmosphere.
Tau, a measure of dust in the atmosphere, has ranged from 0.178 to 0.207 and averaged 0.193. As a result, between 81 percent and 84 percent of the sunlight reaching Mars continues down through the atmosphere to Spirit's solar array. (The remaining 16 percent to 19 percent is either scattered or absorbed by dust particles in the atmosphere. The portion of sunlight that's scattered also contributes to Spirit's solar array energy.)
A Tau this low means the skies above Spirit are remarkably clear. Not only that, Tau has decreased by an average of about 0.01 per week over the last month. (Though scattering and absorption are different and not exactly comparable, a clear mountain day on Earth has a Tau of 0.1-0.2.)
Spirit is healthy and all subsystems are performing as expected as of the Odyssey downlink on Sol 1578 (June 11, 2008). The next planned Odyssey downlink will be on Sol 1582 (June 15, 2008).
What Do You Say When You Call Home?
One of the key ways engineers monitor Spirit is through "event records." These are messages generated by the flight software -- basically, the rover's operating system -- telling Earth how Spirit is doing and why. Most modern operating systems store such information in log files; Spirit transmits it over long distances.
Spirit's event records come in five "flavors." Activity event records note that some event has occurred. Command event records log the issuance and success or failure of commands. Warning event records indicate unexpected events. Fault event records indicate more serious problems the flight software must address, usually by disabling further use of some device or capability. Fatal event records indicate problems so severe they invoke the fault protection features of the operating system. At that point, the whole rover is "disabled" and goes into so-called "safe" mode by shutting down all activities while waiting for instructions from home.
Whether such warnings indicate a problem depends on the context. For example, every time a motor stalls (stops turning while still powered), Spirit's flight software generates a warning event record. Sometimes, the stall is intentional. For example, engineers calibrate the position of an actuator by slowly driving it into a mechanical "hardstop" at a known position. When the hardstop is reached, the motor stalls and issues a warning event record. If one of the motors stalls unexpectedly, that same event record could indicate a problem.
It's like easing into a parking space until your wheels hit the parking bumper. The resulting jolt says you are correctly parked. On the other hand, a similar jolt could mean a fender bender, depending on the context.
Spirit's operators are sending two copies of new command sequences and then sending it twice again on a backup uplink one or two sols later. Data relays are so sparse, they don't always know if the first attempt succeeded and want to minimize the risk of not getting a new sequence on board.
Typically, the first attempt is successful and the second is rejected. Flight software generates event records telling engineers that the rover received the files correctly and copied them into the primary and secondary file systems. The software then rejects the same files later because their names conflict with existing files of the same name.
Rover operators don't actually read all the event reports in text form. An identification number encodes the "flavor" of the event report and a time tag called SCLK for "spacecraft clock" translates the time into readable format. Ground software decodes these and a few other parameters and converts them into readable words.
Sol-by-sol summary
Spirit completed the following activities:
Sol 1574 (June 6, 2008): Spirit recharged the batteries, listened to instructions from Earth for five minutes using the low-gain antenna, measured atmospheric opacity caused by dust using the panoramic camera, and relayed data to the Odyssey orbiter as it passed overhead.
Sol 1575: Spirit recharged the batteries and listened to instructions from Earth for 20 minutes using the high-gain antenna.
Sol 1576: Spirit recharged the batteries, listened to instructions from Earth for five minutes using the low-gain antenna, and measured atmospheric opacity caused by dust using the panoramic camera.
Sol 1577: Spirit recharged the batteries and listened to instructions from Earth for five minutes using the low-gain antenna.
Sol 1578: Spirit recharged the batteries, listened to instructions from Earth for five minutes using the low-gain antenna, measured atmospheric opacity caused by dust using the panoramic camera, and relayed data to Odyssey during the overhead pass of the orbiter.
Sol 1579 (June 12, 2008): Spirit recharged the batteries and listened to instructions from Earth for five minutes using the low-gain antenna.
Odometry:
As of sol 1578 (June 11, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1567-1573, May 30-June 5, 2008: Not Quite Hibernation
To save energy, engineers on Earth are sending new instructions to Spirit once every seven Martian days, or sols, with an additional 10 sols of "runout" instructions in the event of an interruption in communications.
The reason for the reduced workload is that rover engineers are trying to avoid having the state of charge in Spirit's battery go below 8.0 amp-hours (an amp-hour is equivalent to the amount of charge flowing for one hour from a current of 1 amp). By doing so, they hope to avoid a low-power fault condition, during which the rover goes to sleep until it senses that it has enough energy to wake up and communicate with Earth.
Spirit has come close to tripping a low-power fault a couple of times recently, but for the most part, the minimum battery state of charge has hovered around 8.5 amp-hours. Should the battery state of charge drop below that level, engineers would have to consider another course of action, such as further reducing the load or turning off the heater to the miniature thermal emission spectrometer, one of Spirit's scientific instruments.
Rover operators selected Friday as the day for building weekly activity plans for Spirit, because it naturally fits within the two-week cycle of updates to communications "windows" -- opportunities to transmit to and receive data from the rover via NASA's Odyssey spacecraft in orbit above Mars.
Spirit received the first seven-sol plan without a glitch. Preliminary reports indicate power and battery levels remain somewhat steady, but the team will be monitoring those numbers closely.
To further reduce Spirit's workload, engineers could continue to curtail communications via Odyssey as well as direct-from-Earth transmissions to the rover's high-gain antenna. Another approach would be to build activity plans lasting 14 sols, using only one high-gain uplink every two weeks for sending new plans to Spirit (with backups to make sure the rover receives them). Because the high-gain uplinks occur during peak solar power levels on the rover, reducing their frequency would not save as much energy as using fewer Odyssey transmissions.
The other downside is that, while a 14-sol plan would reduce the load on Spirit's battery, it would also result in receiving data less often from the spacecraft. Rover planners could try to listen for direct-to-Earth transmissions indicating potential problems, such as low-power faults or spacecraft clock issues. Still, listening for an indication of trouble does not compare to getting fresh data on a regular basis, making longer planning cycles undesirable.
Spirit is healthy and all subsystems are performing within normal range. Current solar array energy has been around 223 watt-hours per Martian day, or sol (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour).
Sol-by-sol summary
During the past week, Spirit completed the following activities:
Sol 1567 (May 30, 2008): Spirit received new commands from Earth and recharged the batteries.
Sol 1568: Spirit measured atmospheric opacity caused by dust (Tau) with the panoramic camera, sent data to NASA's Odyssey orbiter to be relayed to Earth, and recharged the batteries.
Sol 1569: Spirit soaked up the sunlight to recharge the batteries.
Sol 1570 (June 2, 2008): Spirit measured atmospheric opacity caused by dust (Tau) with the panoramic camera, sent data to NASA's Odyssey orbiter to be relayed to Earth, and recharged the batteries.
Sol 1571: Spirit received new commands from Earth and recharged the batteries.
Sol 1572: Spirit measured atmospheric opacity caused by dust (Tau) with the panoramic camera and recharged the batteries.
Sol 1573 (June 5, 2008): Spirit recharged the batteries.
Odometry:
As of sol 1570 (June 2, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1559-1566, May 22-29, 2008: Energy Levels Reach Record Low
Energy production reached a record low for Spirit this past week. On Sol 1560 (May 23, 2008), solar array input was 220 watt-hours (enough energy to light a 100-watt bulb for two hours and 12 minutes). On sol 1563, Spirit expended the highest amount of energy yet on running heaters to maintain minimum temperatures for batteries (30.6 watt-hours) and the miniature thermal emission spectrometer (54.0 watt-hours). Activity levels on Spirit have been kept low this week to compensate for the reduced energy production.
As was the case last week, Spirit had insufficient energy to transmit data to Earth each day. As a result, the operations team selected which Martian days, or sols, would be used for data downlinks to Earth.
Uplinks of communications from Earth have also been curtailed. Spirit typically has a daily communications window when the rover wakes up and points its High-Gain Antenna toward Earth and listens for new commands. By passing up on some of these uplink opportunities, the rover is able to stay awake for shorter periods of time each sol. Rover operators still have the ability to send new commands if necessary.
Despite low energy levels, Spirit continues to be in good health. The rover continues to conduct atmospheric observations, especially measurements of atmospheric opacity. As explained in last week's report, these Tau measurements of the amount of dust in the atmosphere provide valuable data for science and operations planning because they affect the amount of solar energy that reaches the rover's solar panels.
All subsystems are performing as expected.
Sol-by-sol summary:
In addition to receiving direct-from-Earth instructions over the rover's high-gain antenna, Spirit completed the following activities:
Sol 1559 (May 22, 2008): Spirit received new commands from Earth, measured atmospheric opacity caused by dust (Tau) with the panoramic camera and sent data to NASA's Odyssey orbiter to be relayed to Earth.
Sol 1560: Spirit again measured atmospheric dust with the panoramic camera and recharged the batteries.
Sol 1561: Spirit received new commands from Earth. The rover measured atmospheric darkness caused by dust with the panoramic camera.
Sol 1562: Spirit recharged the batteries.
Sol 1563: Spirit measured atmospheric dust with the panoramic camera and transmitted data to Odyssey.
Sol 1564: Spirit received new commands from Earth.
Sol 1565: Spirit recharged the batteries.
Sol 1566 (May 29, 2008): Spirit measured atmospheric opacity caused by dust with the panoramic camera and sent data to Odyssey to be relayed to Earth.
Odometry:
As of sol 1566 (May 29, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1552-1558, May 15-21, 2008: Some Data Fly First Class, Others Fly Coach and Standby
Lately, Spirit has begun assigning seating priorities to data traveling to Earth. The highest-priority, critical data are like first-class passengers who get to board first, followed by other critical data, who fly coach. These data are guaranteed a seat because they must be returned to Earth to enable engineers to plan the next round of activities.
Non-critical data are like standby passengers. They get to board only if there's room after all the critical data have been seated.
The reason for the seating arrangement is that Spirit's energy levels are so low that the rover has to miss out on some opportunities to transmit data to NASA's Odyssey orbiter, which relays data from the rover to Earth. Odyssey usually passes overhead twice a day, once in the very early morning and again in the afternoon. Spirit hasn't had enough energy to stay awake for a very-early-morning pass in nearly a year, and now is missing some afternoon passes as well.
Uplinks to Odyssey use more energy than the solar arrays have been able to provide, even during peak output at noon. Because Odyssey overflights occur late in the afternoon, they require even more battery power. By deleting some of the Odyssey passes, Spirit saves energy, though doing so limits the amount and "freshness" of the data.
In addition, not all Odyssey passes are created equal. When Odyssey passes directly overhead, communication is excellent, enabling transmission of a large volume of data. When the orbiter is lower in the sky (nearer the horizon), communication can be harder and data volumes smaller.
Last week, a combination of deleted communication links and low data volumes created a problem. The rover wasn't transmitting Tau measurements of sunlight-blocking dust in the Martian atmosphere. Spirit can go a few days without updating Tau measurements, but the longer engineers on Earth go without an update, the greater their uncertainty about actual conditions on Mars. To improve the timeliness of the data, they assigned a much higher priority to new Tau measurements. Spirit used the new priority on Sol 1555 (May 18, 2008).
Overall, Spirit remains healthy and all subsystems are performing as expected.
Energy production was down slightly during the past week, dropping from the previous week's average of 231 watt-hours to an average of 229 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). Instead of remaining constant, energy declined by a watt-hour or two each Martian day, or sol. By the end of the week, power levels were down to 226 watt-hours.
Spirit has been a bit more active, using a little more battery energy and lowering the battery voltage. The lower voltage explains the lower energy production, because environmental factors such as Tau and the dust factor have remained nearly constant.
Tau, a measurement of the loss of sunlight as it passes through the atmosphere, averaged 0.23 the previous week and 0.24 this past week. The 0.01 change represents random fluctuations and is not significant. In both cases, 79 percent of the sunlight hitting Mars' atmosphere reached Spirit's solar arrays.
Spirit measures Tau by taking pictures of the Sun and calculating its brightness. A bright Sun means a low Tau, a dimmer Sun means a higher Tau. The time of day when Tau is measured makes a difference. A noontime Tau measures sunlight through the minimum depth of atmosphere. A sunset Tau measures sunlight as it travels along a slanting path through a thicker swath of atmosphere. By combining the measurements, the rover cancels out losses of sunlight caused by dust on the camera lens.
Tau measures direct sunlight only. As on Earth, dust both blocks and scatters light, and the scattered light changes direction and makes the whole sky seem to "glow." On Earth, the glow is bluish and causes the sky to appear blue. On Mars, the glow is pinkish. Without scattered light, the sky would look pitch black. Scattered light provides some of the rover's solar energy.
Spirit's other measure of energy loss is the dust factor, or the percentage of sunlight reaching the solar arrays that penetrates the dust to make electricity. The average dust factor dropped from 36 percent to 35 percent during the past week, though this, too, was not statistically significant.
Besides foregoing some of the Odyssey uplinks, Spirit has begun eliminating occasional higher-frequency links, known as X-band windows, as well. A communications window is a specific time interval when either the X-band or UHF radio is to be used to send data. When no communications window is active, the system defaults to using the X-band receiver with the low-gain antenna. Because the X-band receiver is always on when the rover is awake, Spirit doesn't save energy simply by deleting a communcations window but is able to wake up later in the day, reducing overall energy use.
On Sols 1557 and 1558 (May 20-21, 2008), Spirit reset the on-board system of fiber-optic gyroscopes and solid-state accelerometers that help the rover keep track of where and how it moves. Known as the inertial measurement unit, the system measures changes in the rover's orientation (yaw, pitch, and roll) and changes in the rover's location. (Activity plans run from roughly noon of one sol to noon of the next sol.)
Because each measurement has a small error, the sum of the measurements can accumulate a significant error (called "drift"). Normally, engineers correct this error by finding the Sun and comparing its actual position to where it would be if the inertial measurement system measurements were exact. Staying up to do that correction (called a "quick fine attitude") takes more energy than Spirit can spare and isn't necessary. Because Spirit hasn't moved since the last time the rover completed a quick fine attitude, engineers are able to use the values measured at that time.
Sol-by-sol summary:
In addition to receiving direct-from-Earth instructions over the rover's high-gain antenna, Spirit completed the following activities:
Sol 1552 (May 15, 2008): Spirit checked for drift (changes with time) in the miniature thermal emission spectrometer and completed a mini-survey of the sky and ground with the instrument. The rover transmitted data to Odyssey during its afternoon pass.
Sol 1553: In the morning, Spirit acquired column 14, part 1 of the full-color "Bonestell panorama," using all 13 filters of the panoramic camera. Spirit measured atmospheric opacity caused by dust (Tau) with the panoramic camera. The rover checked for drift in the miniature thermal emission spectrometer and completed a mini-survey of the sky and ground with the instrument.
Sol 1554: In the morning, Spirit watched the sky for clouds with the navigation camera and acquired spot images of the sky for calibration purposes with the panoramic camera. Later, the rover measured atmospheric dust with the panoramic camera. Spirit checked for drift in the miniature thermal emission spectrometer and completed a mini-survey of the sky and ground with the instrument.
Sol 1555: In the morning, Spirit surveyed the external calibration target with the miniature thermal emission spectrometer, acquired six movie frames in search of clouds with the navigation camera, measured atmospheric dust with the navigation camera, and watched for dust devils. Spirit completed its first critical-priority Tau measurement of atmospheric dust and relayed data to the Odyssey orbiter.
Sol 1556: Spirit conducted no morning science activities and did not receive X-band radio instructions direct from Earth. The rover spent the day recharging the batteries.
Sol 1557: Spirit measured atmospheric dust opacity with the panoramic camera. The rover checked for drift in the miniature thermal emission spectrometer and completed a mini-survey of the sky and ground with the instrument. Spirit transmitted data to Odyssey in the afternoon.
Sol 1558 (May 21, 2008): First thing in the morning, Spirit reset the inertial measurement unit and scanned the sky for clouds with the navigation camera. Later, the rover measured atmospheric dust opacity. Spirit checked for drift in the miniature thermal emission spectrometer and completed a mini-survey of the sky and ground with the instrument. Plans for the next morning called for Spirit to acquire column 16, part 1 of the full-color Bonestell panorama.
Odometry:
As of sol 1557 (May 20, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1546-1551, May 09-14, 2008: Rover Hindered by Moon over Madrid
Though Martian skies have been quite clear, the Moon recently prevented Spirit from having a clear view of Earth. Such events are rare, but during the past week, a lunar occultation prevented instructions from Earth from reaching the rover. In fact, they are so rare that the mission has never before had its communications blocked by a lunar occultation. There have been only two lunar occultations since the rover landed, but because they last only about 30 minutes, there is only a slight chance that they might interfere with a 20-minute uplink from Earth. If Spirit is on an energy-saving communications diet, as it is now, interference is even less likely. Spirit will not see another lunar occultatation at least through the end of 2009.
At first, mission planners thought that light rainfall at NASA's Deep Space Network station near Madrid, Spain, might have absorbed the microwaves used to transmit the instructions. But the rain in Spain wasn't enough to stop the uplink. They also wondered if something was amiss at the station or on board the rover but found nothing wrong. Then someone had a brilliant idea: Where was the Moon? Sure enough, the Moon was directly between Spain and Spirit during the failed uplink on sol 1547 (May 10, 2008).
Winter Wattage
Overall, Spirit remains healthy and all subsystems are performing as expected. Power values have remained remarkably steady and energy has averaged 231 watt-hours, varying by only a single watt-hour (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). Tau, a measure of atmospheric opacity, was 0.23 (resulting in 79 percent of direct sunlight passing through the atmosphere). The other 21 percent was either absorbed or scattered. (The scattered portion contributes to power levels but is not part of the tau measurement.)
The dust factor, too, has been steady at 0.36, meaning that only 36 percent of the sunlight that reaches the rover has been penetrating the dust to make electricity. It is this dust that has made life difficult for Spirit.
Mars passed its aphelion -- the farthest point from the Sun in its orbit -- on Sol 1549 (May 12, 2008) at 10:00 a.m. Local Solar Time, which happened to be 5:14 a.m. Pacific Daylight Time. In the southern hemisphere, where Spirit is located, Mars will be at its winter solstice -- the same day as the summer solstice in the red planet's northern hemisphere -- on Sol 1591 (June 24, 2008) at 22:13 LST (10:30 p.m. Pacific Daylight Time). The winter solstice is effectively the "peak" or mid-point of winter, when the Sun is lowest in the northern sky. Weather conditions for Spirit are expected to improve after that time.
Mars Time
Local Solar Time (LST) is like ordinary civil time on Earth. Sixty Mars seconds make a Mars minute, 60 Mars minutes make a Mars hour, and 24 Mars hours make a Mars day, or sol. Because a sol is as long as 24.66 Earth hours, Mars time intervals are 24.66/24 or 1.027 (2.7 percent) longer than corresponding time intervals on Earth. And, as on Earth, Martian time varies depending on location. Instead of universal time (UTC) or Pacific Daylight Time (PDT), Local Solar Time denotes the time at each rover's site. And just as different locations on Earth can be in different time zones, the rovers are in different time zones denoted "LSTA" or "LSTB."
Sequencing Blackout
Because Spirit is a robot, it needs to be told what to do and when to do it. The time-tagged series of commands for each sol's activities is known as a "sequence." Because it's hard to prepare more than three sequences in a single planning session, the rover's operators limit advance planning to no more than three sols at a time.
Shortly before planning Spirit's schedule of activities for sols 1547-1549 (May 10-12, 2008), engineers learned that their normal uplink session for sol 1550 (May 13, 2008) was needed by another mission. Because it was too late to adjust the sequencing plan and they couldn't create a four-sol plan, they decided to let sol 1550 be a "runout sol," during which the rover conducts very limited and standardized activities while awaiting a new set of instructions. If no new sequences arrive, the rover drops into "automode," waking up only for pre-programmed information exchanges, known as communication windows.
Spirit's operators expected the rover to attempt a standard "handover" from the old sequence for Sol 1549 (May 12, 008) to a new sequence for Sol 1550 (May 13, 2008) and then execute another runout for sol 1549 and attempt a handover to the sequence for sol 1551 (May 14, 2008), which by then would be on board the spacecraft.
Things don't always go as expected. The uplink of instructions on Sol 1547 (May 10, 2008) failed and the sequences for sols 1547-1549 did not get on board. Spirit began executing the runout on sol 1546 (May 9, 2008). Because this occurred on a weekend and the rover was safe, rover operators decided to wait until Monday to retransmit the sequences.
Again, things didn't go as expected. As a result of a lot of complexity, the sequences weren't transmitted on Sol 1549, either! All this time, Spirit continued to execute the sol 1546 runout, trying to hand over first to the Sol 1547 sequence, then the Sol 1548 sequence, and finally the Sol 1549 sequence. None were on board. Finally, after the third attempt, the Sol 1546 sequence ran out and Spirit dropped into automode on Sol 1549 at 11:51 LST.
Spirit remained in automode until the Sol 1551 sequence arrived along with a real-time activate command. The activate command started the Sol 1551 sequence and Spirit was resumed normal operations.
Interestingly, rover operators had planned to delete communications with the Odyssey orbiter to save energy. But Spirit didn't receive those instructions and went ahead and sent data to Earth on sols 1547 and 1549 (May 10 and May 12, 2008). Given the low level of activity during runout and automode, power levels were not adversely affected.
Robotic Arm Hibernation
To conserve power, Spirit's operators originally planned to stow the robotic arm in a winter hibernation position on Sol 1547. It turned out the arm would have been too cold to move without heating and team members had concerns about heating the robotic arm. Rover operators postponed the hibernation date to sol 1551 (May 14, 2008), when startup time would be later in the morning and temperatures would be warmer. They transmitted commands to move the arm. Confirmation wnould have to wait until sol 1552 (May 15, 2008).
The arm will remain in hibernation for several months. Members of the science team considered leaving the Mössbauer spectrometer in place on the soil until they realized they wouldn't have enough power to use it. They were also concerned about the possibility that a joint could fail. If that happened, they couldn't drive the following spring. They chose Spirit's winter hibernation position because it preserved the rover's ability to continue driving if the robotic arm "froze" in place, with the alpha-particle X-ray spectrometer in position to acquire atmospheric argon measurements. (Argon is a trace gas in the atmosphere. By measuring it, scientists can infer changes in barometric pressure).
With the arm in hibernation, Spirit will be ready for the worst of winter. The rover will still be active, acquring more frames of the "Bonestell panorama" as well as other images and measurements, but activity levels will decrease as the winter solstice approaches. Engineers think they may be able to support limited science activities every sol or two.
Sol-by-sol summary:
In addition to receiving direct-from-Earth instructions over the rover's high-gain antenna, Spirit completed the following activities:
Sol 1546 (May 9, 2008): Spirit measured atmospheric opacity caused by dust -- known as tau -- with the panoramic camera, checked for drift (changes with time) in the miniature thermal emission spectrometer, and completed a mini-survey of the sky and ground with the spectrometer. Spirit did not relay data to Odyssey.
Sol 1547: In the morning, Spirit acquired column 16, part 2 of the Bonestell panorama, using all 13 filters of the panoramic camera, and monitored dust accumulation on the panoramic-camera mast assembly. The attempted uplink of a new sequence of activities to the rover was unsuccessful, causing Spirit to execute runout activities. The rover relayed data to Odyssey.
Sol 1548: In the morning, Spirit spent 10 minutes measuring atmospheric opacity caused by dust with the panoramic camera and again conducted runout activities, which included sending data to Odyssey and spending 10 minutes the next morning assessing atmospheric dust with the panoramic camera. The rover did not, as planned, acquire thumbnail images of the sky or complete a horizon survey with the panoramic camera.
Sol 1549: Spirit conducted runout activities and dropped into automode.
Sol 1550: Spirit remained in automode. The rover's only activity was the transmission of data to Odyssey.
Sol 1551 (May 14, 2008): Spirit was to move the robotic arm to the winter hibernation position. The rover was not instructed to communicate with Odyssey.
Odometry:
As of sol 1551 (May 14, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles)
sol 1532-1538, Apr 24-30, 2008: "Catch-22": Staying Awake vs. Going to Sleep
Spirit's Tau measurements of atmospheric dust have remained steady, but solar array input has dropped a bit to 235 watt-hours per sol. Spirit still has enough energy to squeeze in Mössbauer studies of iron-bearing minerals at a time of year when the rover's handlers expected Spirit to be concerned only with survival. At present, the rover's target of scientific interest is a soil exposure nicknamed after Arthur C. Harmon, a former Tuskegee airman. Spirit conducted 8 more hours of Mössbauer integration, for a total of 12 hours. Scientists hope the rover will be able to collect 36 more hours' worth of data from the same target. Meanwhile, Spirit continued to acquire panoramic-camera images, using all 13 color filters, of the "Bonestell panorama," informally named in honor of famed space artist Chesley Bonestell.
Concerned that cold winter temperatures on Mars might trigger the survival heaters on the rover electronics module, rover planners took the extra precaution of disabling those particular heaters on sol 1533 (April 25, 2008) to conserve power. With the heaters turned off, the rover's handlers must monitor temperatures carefully to make sure the module doesn't get too cold. Besides the survival heaters, the remaining means of keeping the module warm enough during the night is to generate more heat during the day by keeping the rover awake for about one additional hour. Of late, 39 minutes is the shortest possible awake time for conducting minimal activities. Another 20-plus minutes of awake time are needed on days when the rover transmits data to NASA's Odyssey orbiter during its overhead pass. On other sols, rover planners may arbitrarily increase the rover's awake time to 50 minutes or longer to generate enough heat to keep the electronics module alive, even if science activities do not require Spirit to be awake that long.
In summary, the challenge for Spirit's handlers during each planning cycle is to recharge the battery enough to do significant science, then recharge the battery again to transmit data to Odyssey for downlink to Earth. By keeping the rover awake for shorter periods, they conserve energy but generate less thermal inertia (heat) for keeping the rover electronics module alive. The more consecutive sols that go by without transmitting temperature and power updates to Odyssey and from there to Earth, the more Spirit's handlers must rely on margin ("wiggle room") from earlier predictions and keep the rover awake longer to protect the electronics module. As a result, Spirit is caught in a "catch-22" set of tradeoffs among power, heat, communications, and science. This delicate balance will become increasingly more precarious as the rover moves closer to the winter solstice, with its even colder temperatures and lower solar array input.
Sol-by-sol summary:
In addition to measuring atmospheric dust levels with the panoramic camera and receiving direct-from-Earth instructions via the rover's high-gain antenna, Spirit completed the following activities:
Sol 1532 (April 24, 2008): Spirit spent 8 hours acquiring data from Arthur C. Harmon with the Mössbauer spectrometer.
Sol 1533: In the morning, Spirit took spot images of the sky with the panoramic camera for calibration purposes and acquired panoramic-camera images of the dune field known as "El Dorado." The rover recharged the battery, disabled the survival heaters on the rover electronics module, and shortened the "Up_Too_Long" computer sequence to 30 minutes.
Sol 1534: Spirit recharged the battery and relayed data to NASA's Odyssey orbiter for transmission to Earth.
Sol 1535: Spirit recharged the battery.
Sol 1536: Spirit recharged the battery and relayed data to the Odyssey orbiter. The rover checked for drift (changes with time) in the miniature thermal emission spectrometer and surveyed the sky and ground with the instrument. The rover was awake for a total of 61 minutes.
Sol 1537: In the morning, Spirit acquired full-color images, using all 13 filters of the panoramic camera, of column 12, part 2 of the Bonestell panorama. The rover recharged the battery, checked for drift in the miniature thermal emission spectrometer, and surveyed the sky and ground with the miniature thermal emission spectrometer. Spirit was awake for a total of 39 minutes.
Sol 1538 (April 30, 2008): Spirit checked for drift in the miniature thermal emission spectrometer and surveyed the sky and ground with the instrument. After sending data to Odyssey, the rover used the alpha-particle X-ray spectrometer to measure argon gas in the Martian atmosphere. Plans for the next morning called for Spirit to complete work on column 12, part 3 of the Bonestell panorama.
Odometry:
As of sol 1538 (April 30, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1525-1531, Apr 17-23, 2008: Rover "Spirit" High Despite Low Power Levels
Given the substantial coating of dust on the solar array, Spirit continues to enjoy energy levels that are higher than expected for this time of year, at around 240 watt-hours per sol (enough energy to light two 100-watt bulbs and one 40-watt bulb for one hour).
Spirit continues to make progress on the full-color "Bonestell panorama" of the rover's winter surroundings. Of 27 columns of stacked images needed for a complete mosaic, Spirit has completed work on 11 columns, each comprising three parts. Each Martian day, or sol, Spirit has enough energy to complete one part. Science team members have nicknamed the panorama after Chesley Bonestell (1888-1986), considered the father of modern space art.
Analysis of iron-bearing minerals in a patch of undisturbed soil will require an estimated 24 hours of data collection during the coming week with the Mössbauer spectrometer. The soil target is known informally as "Arthur C. Harmon." Spirit can complete 4 to 8 hours of integration with the spectrometer before needing to recharge the batteries. To conserve power, Spirit is on a communications diet, in which the rover limits data transmissions to Earth to, at most, every other sol.
Spirit is healthy and all systems are operating as expected.
Sol-by-sol summary:
In addition to communication activities that include direct-from-Earth instructions via the rover's high-gain antenna and, power permitting, data relays to Earth via the Odyssey orbiter, Spirit continues to monitor atmospheric dust levels with the panoramic camera, check for drift (changes with time) in the miniature thermal emission spectrometer, and survey the sky and ground with the spectrometer. During the past week, Spirit also completed the following activities:
Sol 1525 (April 17, 2008): Spirit acquired column 10, part 1 of the Bonestell panorama, using all 13 filters of the panoramic camera.
Sol 1526: In the morning, Spirit surveyed the external calibration target with the miniature thermal emission spectrometer and parked the panoramic camera mast assembly with the panoramic camera pointed below the horizon to minimize dust accumulation.
Sol 1527: In the morning, Spirit completed work on column 10, part 2 of the Bonestell panorama, then parked the panoramic camera mast assembly with the panoramic camera pointed below the horizon to minimize dust accumulation. The rover exchanged tools to put the Mössbauer spectrometer in position to study Arthur C. Harmon.
Sol 1528: Spirit spent the morning working on column 10, part 3 of the Bonestell panorama. The rover relayed data to Odyssey for transmission to Earth.
Sol 1529: Spirit acquired column 11, part 1 of the Bonestell panorama and spent 4.5 hours acquiring data from Arthur C. Harmon with the Mössbauer spectrometer.
Sol 1530: In the morning, Spirit monitored dust on the panoramic camera mast assembly and acquired column 11, part 2 of the Bonestell panorama. The rover then completed work on column 11, part 3 of the panorama and relayed data to Odyssey.
Sol 1531: (April 23, 2008): Spirit recharged the battery. The following morning, Spirit was to acquire column 12, part 1 of the Bonestell panorama.
Odometry:
As of sol 1531 (April 23, 2008), Spirit's total odometry remained at 7,528.0 meters (4.7 miles).
sol 1517-1524, Apr 09-16, 2008: Spirit Still "Sitting Pretty" for This Time of Year
Despite a slight increase in atmospheric opacity caused by dust, Spirit is still enjoying higher-than-expected energy levels for this time of year. Solar array input has been approximately 240 watt-hours per Martian day, or sol (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour).
Clear skies have had the unfavorable effect, however, of causing a drop in temperatures at the surface of Mars, increasing the bitter cold experienced by Spirit's rover electronics module. Nighttime temperatures are creeping closer to the point where they will trigger the survival heaters, which draw a large amount of power. A much more desirable strategy is to keep Spirit awake long enough each day to keep the electronics module sufficiently warm with heat from normal operations, providing more time for science observations. "Awake time" vs. heating time is just one of the many trade-offs the team makes each day to keep Spirit going through the Martian winter.
Sol-by-sol summary:
In addition to daily communications that include direct-from-Earth instructions via the rover's high-gain antenna and, as power permits, data relays to Earth via the Odyssey orbiter, Spirit continues to monitor atmospheric dust levels each day with the panoramic camera. In addition, during the past week, Spirit completed the following activities:
Sol 1517 (April 9, 2008): Spirit completed a mini-survey of the sky and ground with the miniature thermal emission spectrometer; acquired column 8, part 3 of the full-color "Bonestell Panorama" using all 13 filters of the panoramic camera; and shot movie frames in search of clouds with the navigation camera.
Sol 1518: Spirit completed a mini-survey of the sky and ground with the miniature thermal emission spectrometer; acquired a 2-by-1-by-1 stack of microscopic images of the rover's solar array; acquired column 9, part 1 of the Bonestell panorama; and took spot images of the sky for calibration purposes with the panoramic camera.
Sol 1519: Spirit surveyed the rover's external calibration target with the miniature thermal emission spectrometer and acquired column 9, part 2 of the Bonestell panorama. To conserve energy, the rover did not relay data to Odyssey.
Sol 1520: Spirit completed a mini-survey of the sky and ground with the miniature thermal emission spectrometer; measured atmospheric opacity caused by dust with the navigation camera (as well as the panoramic camera); and acquired movie frames in search of clouds with the navigation camera. The rover took spot images of the sky and surveyed the horizon with the panoramic camera. Spirit did not relay data to Odyssey.
Sol 1521: Spirit completed a mini-survey of the sky and ground with the miniature thermal emission spectrometer; calibrated the elevation of the miniature thermal emission spectrometer; and acquired column 9, part 3 of the Bonestell panorama.
Sol 1522: Spirit completed a mini-survey of the sky and ground with the miniature thermal emission spectrometer; took thumbnail images of the sky and surveyed the horizon with the panoramic camera; and acquired lossless-compression images of wind-blown deposits next to the rover with the hazard-avoidance cameras. Spirit did not relay data to Odyssesy.
Sol 1523: Spirit recharged the battery and did not relay data to Odyssey.
Sol 1524: (April 16, 2008): Spirit recharged the battery.
Odometry:
As of sol 1524 (April 16, 2008), Spirit's total odometry remained at 7,528.07 meters (4.68 miles).
sol 1511-1516, Apr 03-08, 2008: Clear Skies at "Home Plate"
Spirit is currently experiencing the clearest skies seen by either of NASA's two Mars Exploration Rovers. On sol 1511 (April 3, 2008), Tau measurements of atmospheric dust hit an all-time low of 0.127. By sol 1516 (April 8, 2008), this measurement had increased slightly to 0.170. The low Tau values have held power levels at around 250 watt-hours (enough energy to light a 100-watt bulb for about 2.5 hours). If Tau were not so cooperative, Spirit would be getting only about 200 watt-hours of energy, compelling the rover's handlers to disable the heaters on the miniature thermal emission spectrometer and take other measures to conserve power.
The engineering team still expects to implement energy-conservation strategies, but not for several weeks. Meanwhile, Spirit continues to make progress on remote-sensing activities, scientific investigations, and the "Bonestell panorama" of the rover's view from the north rim of "Home Plate."
Sol-by-sol summary:
To conserve energy, mission planners have restricted the number of sols on which Spirit receives direct-from-Earth instructions via the rover's high-gain antenna and transmits data to Earth via the Odyssey orbiter. Spirit continues, on a daily basis, to monitor atmospheric dust levels with the panoramic camera and survey the sky and ground with the miniature thermal emission spectrometer. In addition, during the past week, Spirit completed the following activities:
Sol 1511 (April 3, 2008): Spirit took thumbnail images of the sky with the panoramic camera.
Sol 1512: Spirit gathered compositional data from the soil target known as "Arthur C. Harmon" using the alpha-particle X-ray spectrometer. The rover used the panoramic camera to acquire super-resolution images of a target informally named "Arthur C. Clarke."
Sol 1513: Spirit acquired column 7, part 3 of the full-color Bonestell panorama, using all 13 filters of the panoramic camera.
Sol 1514: Spirit pointed the alpha-particle X-ray spectrometer skyward to measure argon gas in the Martian atmosphere and acquired stability images of the rover's 30-degree tilt. The rover transmitted data to Odyssey and spent about 4.5 hours measuring atmospheric argon. Spirit also acquired column 8, part 1 of the Bonestell panorama and took spot images of the sky for calibration purposes with the panoramic camera.
Sol 1515: Spirit surveyed the sky with the panoramic camera and monitored dust on the panoramic camera mast assembly.
Sol 1516: (April 8, 2008): Spirit acquired column 8, part 2 of the Bonestell panorama and surveyed the horizon with the panoramic camera.
Odometry:
As of sol 1516 (April 8, 2008), Spirit's total odometry remained at 7,528.07 meters (almost 4.68 miles).
sol 1504-1510, Mar. 27 - Apr 02, 2008: Spirit Advances Toward Midwinter
Seasons are about twice as long on Mars as on Earth and are offset relative to Earth because Mars takes about twice as long to complete one orbit around the Sun. At Spirit's location, the fall equinox -- the start of fall, when night and day are equal in length -- arrived Dec. 12, 2007. The winter solstice -- the time of year with the shortest day -- will arrive June 25, 2008.
Solar array energy has varied from 244 watt-hours to 256 watt-hours, averaging 250.4 watt-hours for this period (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). Tau, the measure of atmospheric dust, has averaged 0.16, varying by only a hundredth. The dust factor has been nearly constant at 0.35, meaning 35 percent of the sunlight reaching the arrays penetrates the dust layer to make electricity. A low Tau is good because it means the skies are fairly clear; a low dust factor is bad because it means the solar arrays are coated with a fair amount of dust.
Astronomers use the symbol L(s) -- pronounced L-sub-s -- to denote how far Mars has progressed in its orbit around the Sun. If you imagine looking down at the solar system, with the Sun in the middle and Mars orbiting around it, L(s) gives the location of Mars. By definition, L(s) = 0 degrees when the Sun crosses the Martian equator. This is the first day of Martian spring, the vernal equinox, when night and day are equal in length, in the northern hemisphere. It's also the first day of fall, the autumnal equinox, in the southern hemisphere. At Spirit's location in Mars' southern hemisphere, the season is currently mid- to late fall, and L(s) is about 55 degrees, roughly equivalent to Nov. 17 in Earth's northern hemisphere and May 18 in Earth's southern hemisphere. L(s) will equal 90 degrees at the time of the winter solstice.
Spirit is healthy and all subsystems are performing as expected.
Sol-by-sol summary:
To conserve energy, mission planners have restricted the number of sols on which Spirit receives direct-from-Earth instructions via the rover's high-gain antenna and transmits data to Earth via the Odyssey orbiter. Spirit continues, on a daily basis, to monitor atmospheric dust levels with the panoramic camera, check for drift (changes with time) in the miniature thermal emission spectrometer, and survey the sky and ground with the instrument. In addition, during the past week, Spirit completed the following activities:
Sol 1504 (March 27, 2008): Spirit calibrated the miniature thermal emission spectrometer and acquired a microscopic image of the capture magnet.
Sol 1505: Upon awakening, Spirit took spot images of the sky for calibration purposes with the panoramic camera and acquired column 6, part 1 of the full-color "Bonestell panorama" using all 13 filters of the panoramic camera. The rover also recharged the battery.
Sol 1506: Spirit acquired column 6, part 2 of the Bonestell panorama and monitored dust on the panoramic-camera mast assembly. Spirit looked at the miniature thermal emission spectrometer for calibration purposes, acquired microscopic images of the solar panel, and acquired images of the external magnets, which capture magnetic dust particles, using the panoramic camera.
Sol 1507: Spirit acquired column 6, part 3 of the full-color Bonestell panorama and recharged the battery.
Sol 1508: Spirit acquired column 7, part 1 of the full-color Bonestell panorama and relayed data to Odyssey during the orbiter's afternoon pass overhead.
Sol 1509: Spirit surveyed the sky at high Sun with the panoramic camera and completed a "runout" of previously loaded activities after not being able to receive new instructions from Earth. The rover recharged the battery and relayed data to Odyssey.
Sol 1510: (April 2, 2008): Spirit acquired a 1-by-1-by-3 stack of microscopic images of a soil target known informally as "Arthur_C_Hammon" and placed the alpha-particle X-ray spectrometer on the soil target. Plans for the following morning called for Spirit to acquire column 7, part 2 of the full-color Bonestell panorama.
Odometry:
As of sol 1509 (April 1, 2008), Spirit's total odometry was 7,528 meters (almost 4.7 miles).
sol 1498-1503, Mar. 20-26, 2008: Spirit Sees Clearest Skies Since Landing on Mars!
Like a calm after the recent Martian dust storms, atmospheric dust above Spirit's overwintering site has reached the lowest levels the rover has seen since arriving on Mars. To be sure, sunblocking dust that has settled on the rover's solar panels and low-angle winter sunlight have combined to reduce Spirit's energy levels. But clear skies mean more sunlight penetrates the atmosphere, making rover planners optimistic that Spirit will have a slim but adequate amount of energy to survive until Martian spring.
Earlier estimates predicted a near-starvation energy diet for Spirit during the darkest days of winter. The coming winter solstice, the peak of Martian winter, will be June 25, 2008. To conserve energy, Spirit may have to disable some heaters and curtail communications and other activities, but is expected to be able to conduct limited scientific investigations.
Solar-array energy during the past week has varied between 244 watt-hours and 254 watt-hours, averaging 249.5 watt-hours for the period (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). Tau, the measure of atmospheric dust, has averaged 0.2, varying by only a few hundredths. The dust factor has been nearly constant at 0.36 (meaning 36 percent of the sunlight reaching the arrays penetrates the dust layer to make electricity). A low Tau is good; a low dust factor is bad.
Because dust is constantly settling out from the Martian atmosphere onto the solar arrays, Tau and the change in the dust factor are related. When Tau is high, the dust factor rapidly decreases as dust from the atmosphere rains onto the arrays. When Tau is low (as it is now), the atmosphere carries less dust and the dust factor decreases more slowly. The clearer atmosphere doesn't affect dust already on the solar arrays, but it does affect the rate at which new dust is added.
The atmosphere above the Spirit site is remarkably clear at present and Tau has been as low as 0.170 -- the lowest seen by Spirit in the entire mission. Not surprisingly, the dust factor has been virtually unchanged.
Spirit also analyzed material on the external capture magnet. Spirit has several magnets of which two, the capture and filter magnets, are mounted at the front of the solar array. The capture magnet is relatively strong, the filter magnet only half as strong.
Viking data from the 1970s showed that Martian dust was slightly magnetic, comprising 1 to 7 percent magnetic material. Spirit's filter and capture magnets winnow the dust for this material. The capture magnet, being stronger, gathers all magnetic materials while the filter magnet retains only the most magnetic particles. Using the alpha-particle X-ray spectrometer, Spirit can determine the chemical composition of the captured particles. The observations will help scientists ascertain whether the magnetic material is uniform or has more than one constituent. The dust composition provides insight into whether the magnetic material is the product of weathering in the presence of water or weathering of dry bedrock.
Spirit continued to scale back the frequency of afternoon communications with the Odyssey orbiter to save energy. Overhead passes by Odyssey happen late in the day when little solar energy is available, requiring the use of significant battery power. By deleting some of the passes, Spirit can conserve energy acquired earlier in the day to provide power for subsequent science observations. The downside is that fewer passes slow the rate at which pictures and other data can be downlinked to Earth.
Spirit continued work on the Bonestell (Bon-ES-tell) panorama, a high-resolution, 360-degree mosaic of images divided into wedges (columns) spanning roughly 5 compass degrees and extending from near the rover to just above the horizon. Each column typically has three or four separate images or "parts." The panorama is named for Chesley Bonestell (1888-1986), considered the "father of modern space art."
Spirit is healthy and all subsystems are performing as expected.
Sol-by-sol summary:
To conserve energy, mission planners have restricted the number of sols on which Spirit receives direct-from-Earth instructions via the rover's high-gain antenna and transmits data to Earth via the Odyssey orbiter. Spirit continues, on a daily basis, to monitor atmospheric dust levels with the panoramic camera, check for drift (changes with time) in the miniature thermal emission spectrometer, and survey the sky and ground with the instrument. In addition, during the past week, Spirit completed the following activities:
Sol 1498 (March 20, 2008): Spirit placed the alpha-particle X-ray spectrometer on the capture magnet, took images with the hazard avoidance cameras, took images with the navigation camera for lossless-compression visual odometry, and relayed data to Odyssey.
Sol 1499: Spirit acquired column 4, part 2 of the full-color Bonestell panorama, using all 13 filters of the panoramic camera.
Sol 1500: Spirit acquired column 4, part 3 of the full-color Bonestell panorama, using all 13 filters of the panoramic camera.
Sol 1501: Spirit acquired column 5, part 1 of the full-color Bonestell panorama and relayed data to Odyssey during the orbiter's afternoon pass.
Sol 1502: Spirit took six movie frames in search of clouds with the navigation camera and acquired column 5, part 2 of the Bonestell panorama. Using the alpha-particle X-ray spectrometer, Spirit acquired data on the elemental composition of magnetic particles on the external capture magnet.
Sol 1503 (March 26, 2008): Spirit acquired column 5, part 3 of the Bonestell panorama and relayed data to Odyssey. Plans for the following morning called for Spirit to acquire super-resolution images of a rock target informally named "Roger_Zelazny" (after the science fiction author) with the panoramic camera.
Odometry:
As of sol 1501 (March 23, 2008), Spirit's total odometry was 7,528.07 meters (4.68 miles).
sol 1491-1497, Mar. 13-19, 2008: Spirit Phones Home to Set Clock
Spirit is feeling the strain of juggling activities on Mars in the face of declining power levels as the winter Sun sinks lower on the horizon. After acquiring compositional data from a rock target informally named "Wendell Pruitt," Spirit had to wait a few sols (Martian days) to have enough energy to conduct atmospheric studies and move the robotic arm out of the way for a panoramic-camera portrait of a rock target known as "Freeman." First, the rover had to make a "phone call" to Earth to correct for drift -- changes in time -- in the spacecraft clock.
When Spirit phones home using a direct-to-Earth, X-band communications link, the rover's transmitter has to be running, which requires a fair amount of energy. During more typical, direct-from-Earth communications, only the rover's receiver has to be on. To set the spacecraft clock, Spirit transmits a data product called a time packet. The time packet is used to synchronize the rover's clock back to Earth time (also known as Universal Time). A previous attempt to relay the time packet was unsuccessful, causing Spirit's clock to be off by as much as a minute and a half.
In addition to resetting the clock, Spirit completed a light schedule of activities on sols 1493-1494 (March 15-16, 2008). By sol 1496 (March 18, 2008), Spirit had generated enough solar power to proceed with measurements of argon gas in the Martian atmosphere and studies of the Freeman rock target. Interspersed with those activities, Spirit continued to work on the "Bonestell panorama" and take panoramic-camera images of a target dubbed "C.S. Lewis." The rover spent sols 1492, 1494, and 1497 (March 14, 16, and 19, 2008) recharging the battery, conducting only minimal science activities, and storing data for later transmission to Earth.
Spirit continued to have difficulty receiving spacecraft commands via the rover's high-gain, X-band, dish antenna as a result of the mast that holds the panoramic and navigation cameras getting in the way and partially obscuring the signal. To help address this challenge, rover planners had Spirit complete a self-assessment to see if the rover could independently recognize an occlusion of the high-gain signal and respond by swiveling the high-gain antenna to a different position. The self-assessment, on sol 1493 (March 15, 2008), was successful. Spirit used the technique prior to an actual uplink session on sol 1496 (March 18, 2008), when the rover's handlers were expecting a particularly severe occlusion. The activity was successful and the uplink did not appear to be impeded in any way. Currently, this activity involves having the rover use a temporary parameter that then goes away when the rover shuts down for a nap. Rover planners are considering making the temporary parameter permanent.
Looking forward, Spirit will go increasingly into "hibernate" mode as the Sun continues to dim. Rover planners predict Spirit will be able to conduct science activities until about late April.
Spirit is healthy and all subsystems are performing as expected. The latest available power readings from sol 1496 (March 18, 2008) showed power at 249 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). Spirit has no plans to move before the next Martian spring and is hard at work accomplishing as much as possible before power levels drop to a point that temporarily precludes use of the scientific instruments on the rover's arm.
Sol-by-sol summary:
To conserve energy, mission planners have restricted the number of sols on which Spirit receives direct-from-Earth instructions via the rover's high-gain antenna and transmits data to Earth via the Odyssey orbiter. Spirit continues, on a daily basis, to monitor atmospheric dust levels with the panoramic camera, check for drift (changes with time) in the miniature thermal emission spectrometer, and survey the sky and ground with the instrument. In addition, during the past week, Spirit completed the following activities:
Sol 1491 (March 13, 2008): After communicating with Odyssey, Spirit studied the elemental composition of "Wendell Pruitt" with the alpha-particle X-ray spectrometer.
Sol 1492: In addition to monitoring atmospheric dust and conducting surveys with the miniature thermal emission spectrometer, Spirit recharged the battery.
Sol 1493: Spirit initiated a direct-to-Earth communications link using the X-band antenna and transmitted a data packet to correct the spacecraft clock.
Sol 1494: In addition to monitoring atmospheric dust and conducting surveys with the miniature thermal emission spectrometer, Spirit recharged the battery.
Sol 1495: In the morning, Spirit acquired column 3, part 1 of the full-color Bonestell panorama, using all 13 filters of the panoramic camera. Spirit positioned the alpha-particle X-ray spectrometer to measure argon gas in the Martian atmosphere. The rover took a single-frame image with the navigation camera. After communicating with Odyssey, Spirit measured argon with the alpha-particle X-ray spectrometer.
Sol 1496: Spirit monitored dust accumulation on the rover mast and acquired column 3, part 3 of the full-color Bonestell panorama. The rover acquired full-color images, using all 13 filters of the panoramic camera, of the Freeman rock target.
Sol 1497 (March 19, 2008): Spirit looked for changes in the "El Dorado" dune field with the panoramic camera and acquired column 4, part 1 of the Bonestell panorama. The rover recharged the battery. The following morning, Spirit was to acquire movie frames in search of clouds with the navigation camera, acquire super-resolution, panoramic-camera images of a target dubbed "C.S. Lewis half," and survey the horizon with the panoramic camera.
Odometry:
As of sol 1496 (March 18, 2008), Spirit's total odometry was 7,528 meters (almost 4.7 miles).
sol 1484-1490, Mar. 6-12, 2008: Spirit Begins Preparing for "Hibernation" Mode
Spirit has reached its final position for the coming Martian winter and has no plans to move before the next Martian spring. During the next few months, the rover will increasingly go into a "hibernate" mode as the sun continues to dim.
Spirit is currently wrapping up a campaign of scientific studies of the rock target known as "Wendell Pruitt," interspersed with remote science observations of targets nicknamed "Lucius Theus" and "Theopolis Johnson." These targets were all named in honor of distinguished members of the "Tuskegee Airmen," the popular name for the 332nd Fighter Group, an all African-American unit of the U.S. Army Air Corps that served in the European Theater during World War II.
Spirit's previous attempt to use the wire brush on the rock abrasion tool on sol (Martian day) 1479 (March 1, 2008) failed to sufficiently brush the surface of Wendell Pruitt. The rover repeated the effort on sol 1484 (March 6, 2008) with greater success. On sol 1486 (March 8, 2008), Spirit acquired a 2-by-2-by-5 stack of stereo microscopic images of Wendell Pruitt. The rover placed the alpha-particle X-ray spectrometer on the target on sol 1489 (March 11, 2008) but postponed data collection with the instrument to conserve power for an operational readiness test in support of the Phoenix mission scheduled for the late morning of sol 1491 (March 13, 2008). At that time, the rover was to send a tone at UHF frequencies directly to the Green Bank radio telescope in West Virginia. The tone was to serve as a beacon; the rover would not be transmitting data.
Spirit continued to take panoramic-camera images for the 360-degree "Bonestell panorama." The rover recharged its battery on sols 1485, 1487, 1488, and 1490 (March 7, 9, 10, and 12, 2008). On recharge days, the rover typically conducts minimal science activity and does not relay Eartbound data to the Odyssey orbiter as it passes overhead.
A complication in Spirit's current circumstances is that the mast holding the panoramic and navigation cameras is partially obscuring the X-band, high-gain antenna that Spirit's handlers use to command the spacecraft from Earth. Engineers have been experimenting with "parking" these instruments in positions that minimize this obscuration.
Spirit is healthy and all subsystems are performing as expected. The latest available power readings from sol 1489 (March 11, 2008) showed power at 254 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour).
Sol-by-sol summary:
To conserve energy, mission planners have restricted the number of sols on which Spirit receives direct-from-Earth instructions via the rover's high-gain antenna and transmits data to Earth via the Odyssey orbiter. Spirit continues, on a daily basis, to monitor atmospheric dust levels with the panoramic camera, check for drift (changes with time) in the miniature thermal emission spectrometer, and survey the sky and ground with the instrument. In addition, during the past week, Spirit completed the following activities:
Sol 1484 (March 6, 2008): Spirit brushed the surface of Wendell Pruitt, acquired a single-frame, lossless-compression (high-resolution) image of the area in front of the rover with the navigation camera, and took stereo images with the front hazard avoidance cameras.
Sol 1485: Spirit acquired super-resolution images of half of Lucius Theus and recharged the battery.
Sol 1486: Spirit surveyed the horizon and took spot images of the sky for calibration purposes with the panoramic camera. Spirit monitored dust on the rover mast and acquired a 2-by-2-by-5 stack of stereo microscopic images of Wendell Pruitt. The rover acquired a single-frame, lossless-compression image of the area in front of the rover with the navigation camera as well as stereo images with the front hazard avoidance cameras.
Sol 1487: In the morning, Spirit acquired column 2, part 3 and column 3, part 1 of the full-color Bonestell panorama, using all 13 filters of the panoramic camera, then spent much of the Martian day recharging the battery.
Sol 1488: In the morning, Spirit used the navigation camera to take images of the sky (called "sky flats") for calibration purposes and used the panoramic camera to take super-resolution images of Theopolis Johnson. The rover turned the panoramic camera mast assembly to prepoint the camera, then recharged the batteries.
Sol 1489: Spirit placed the alpha-particle X-ray spectrometer on Wendell Pruitt and, after relaying data to Odyssey, acquired data with the instrument.
Sol 1490 (March 12, 2008): Spirit acquired column 3, part 2 of the Bonestell panorama and recharged the batteries. Plans for the next morning called for Spirit to acquire thumbnail panoramic-camera images of the sky looking starboard (to the rover's right) for calibration purposes.
Odometry:
As of sol 1489 (March 11, 2008), Spirit's total odometry remained at 7,528.07 meters (4.68 miles).
sol 1478-1483, Feb. 29- Mar. 05, 2008: Work Continues on 360-Degree View of Spirit's Winter Perch
Spirit continued work on the "Bonestell panorama," a full-color, 360-degree view of the rover's surroundings from its overwintering perch on the north-facing edge of "Home Plate." Spirit acquired images for the panoramic mosaic on sols 1478, 1479, 1480 and 1483 (Feb. 29, March 1-2, and March 5, 2008). By the time the final product is ready, the rover will have completed an estimated 60 separate pointings of the panoramic camera in all different directions. Rover planners have nicknamed the panorama in honor of Chesley Bonestell (1888-1986), considered the father of modern space art.
Spirit has also been engaged in efforts to brush away dust from a rock target known as "Wendell Pruitt." The rover used the rock abrasion tool to brush the surface on sol 1479 (March 1, 2008), but the brushing cleared only about half the expected area. On the basis of the results, the rover's handlers adjusted the command sequence to have Spirit perform a "grind scan" to locate the surface of Wendell Pruitt on sol 1482 (March 4, 2008). The goal of this maneuver was to get the rock abrasion tool in place for another attempted brushing, scheduled for sol 1484 (March 6, 2008).
Spirit is healthy and all subsystems are performing as expected.
Sol-by-sol summary:
To conserve energy, mission planners have restricted the number of sols on which Spirit receives direct-from-Earth instructions via the rover's high-gain antenna and transmits data to Earth via the Odyssey orbiter. Spirit continues, on a daily basis, to monitor atmospheric dust levels with the panoramic camera, check for drift (changes over time) in the miniature thermal emission spectrometer, and survey the sky and ground with the instrument. In addition, during the past week, Spirit completed the following activities:
Sol 1478 (Feb. 29, 2008): Spirit acquired column 1, part 2 of the full-color, panoramic camera images, using all 13 filters of the camera, that will make up the Bonestell panorama. Spirit also recharged the batteries.
Sol 1479: Using the wire brush on the rock abrasion tool, Spirit brushed the surface of Wendell Pruitt. The rover acquired a single-frame, lossless-compression (highly detailed) image of the area in front of the rover using the navigation camera. Spirit relayed data at UHF frequencies to NASA's Odyssey orbiter for transmission to Earth.
Sol 1480: Spirit acquired column 1, part 3 of the Bonestell panorama and measured argon gas in the Martian atmosphere with the alpha-particle X-ray spectrometer.
Sol 1481: Spirit acquired column 2, part 1 of the Bonestell panorama, and recharged the batteries.
Sol 1482: Spirit acquired an image with the panoramic camera pointing south, then completed "Grind Scan2" of the surface of "Wendell Pruitt." The rover acquired a single-frame, lossless-compresson image of the area in front of the spacecraft with the navigation camera. Spirit relayed data at UHF frequencies to NASA's Odyssey orbiter for transmission to Earth.
Sol 1483 (March 5, 2008): Early in the day, Spirit acquired a super-resolution image of the target nicknamed "FredericBrown half" with the panoramic camera. The rover recharged the batteries. The following morning, Spirit was to acquire full-color, panoramic camera images of column 2, part 2 of the Bonestell panorama.
Odometry:
As of sol 1482 (March 4, 2008), Spirit's total odometry remained at 7,528.07 meters (4.68 miles).
sol 1471-1477, Feb. 22-28, 2008: Sturdy Rover Gets No Penalty for Tilting
Scarcely a pinball wizard on Earth could tilt the machine nearly 30 degrees without ending play, yet engineers tilted NASA's Spirit rover 29.9 degrees and completed the robotic equivalent of a one-armed toe-touch to test its stability. The rover remained in play, racking up scientific data points after remaining perfectly balanced even while pressing the ground with the Möessbauer spectrometer at the end of its robotic arm.
During the past week, Spirit began work on a 360-degree, full-color panorama of the rover's winter surroundings as viewed from the north edge of the elevated, volcanic plateau known as "Home Plate." The resulting mosaic of high-resolution images, to be acquired during approximately 60 individual pointings of the panoramic camera, will be nicknamed the "Bonestell panorama" in honor of Chesley Bonestell (pronounced BON-es-tell), a science fiction illustrator and designer. (Last year's spectacular image mosaic of Spirit's winter haven was called the "McMurdo panorama.")
Spirit took microscopic images of dust that has settled out of the Martian sky onto the solar panels. The rover also made two attempts to complete the first of a two-part process for brushing the surface of a rock target dubbed "Wendell Pruitt" with the rock abrasion tool, another of the instruments on the rover's robotic arm. Because the results were inconclusive after the first try, Spirit's handlers decided to have the rover repeat the procedure, known as a "grind scan," during which the rover locates the surface by touching it with the brush and the grinding bit, two days later. The second attempt was successful, clearing the way for actual brushing of Wendell Pruitt.
Spirit is healthy and all subsystems are performing as expected.
Sol-by-sol summary:
In addition to measurements of atmospheric dust levels with the panoramic camera and daily communications activities, which include morning direct-from-Earth uplinks over the rover's high-gain antenna and evening relays to Earth via the UHF antenna on the Mars Odyssey orbiter, Spirit completed the following activities:
Sol 1471 (Feb. 22, 2008): Spirit completed a mini-survey of the sky and ground with the miniature thermal emission spectrometer, touched the ground and exerted 10 newtons of force with the Möessbauer spectrometer to test the rover's stability at the new tilt of 29.9 degrees, and acquired super-resolution images of a target dubbed "Gekko." Spirit took spot images of the sky for calibration purposes using the panoramic camera.
Sol 1472: Spirit checked for drift (changes over time) in the miniature thermal emission spectrometer, surveyed the external calibration target and completed a mini-survey of the sky and ground with the miniature thermal emission spectrometer, and acquired super-resolution images of a rock target known as "Monolith" with the panoramic camera.
Sol 1473: Spirit acquired full-color images, using all 13 filters of the panoramic camera, of a rock target dubbed "William A. Johnston," a deceased member of the Tuskegee Airmen. Spirit checked for drift in the miniature thermal emission spectrometer, completed a mini-survey of the sky and ground with the instrument, and acquired a 2-by-2-by-1 stack of microscopic images of a target on the rover's solar panels as well as microscopic images of the external capture magnet and filter magnet. The rover acquired single-frame, lossless-compression (high-definition) images of the area directly in front of the rover with the navigation camera.
Sol 1474: Spirit monitored dust on the rover mast, surveyed the sky at varying elevations and the ground with the miniature thermal emission spectrometer, completed another mini-survey of the sky and ground, and checked for drift in the spectrometer.
Sol 1475: Spirit took full-color images, using all 13 filters of the panoramic camera, of a rock target nicknamed "Bennett Hardy" (also a Tuskegee Airman). The rover checked for drift in the miniature thermal emission spectrometer and completed a mini-survey of the sky and ground with the instrument. Spirit made the first attempt to use a grind-scan procedure to contact the surface of Wendell Pruitt. The rover took single-frame, lossless-compression (high-definition) images with the navigation camera.
Sol 1476: Spirit acquired super-resolution images of a rock target dubbed "Reuben C. Franklin" (a Tuskegee Airman) with the panoramic camera, checked for drift in the miniature thermal emission spectrometer, and completed a mini-survey of the sky and ground with the instrument. The rover took diagnostic images of the rock abrasion tool and recharged the batteries.
Sol 1477 (Feb. 28, 2008): Spirit acquired column 1 of part 1 of the full-color Bonestell panorama, using all 13 filters of the panoramic camera. The rover checked for drift in the miniature thermal emission spectrometer and completed a mini-survey of the sky and ground with the instrument. Spirit completed the second, successful attempt to locate the surface of Wendell Pruitt using the grind-scan procedure with the rock abrasion tool. The rover acquired single-frame, lossless-compression images with the navigation camera. Plans for the following morning called for Spirit to point the panoramic camera starboard and take thumbnail images of the sky.
Odometry:
As of sol 1476 (Feb. 27, 2008), Spirit's total odometry remained at 7,528.07 meters (4.68 miles).
sol 1464-1470, Feb. 14-21, 2008: Tenacious Rover Just Might Make It
Spirit has achieved a northerly tilt of 29.9 degrees! As a result, based on power projections, Spirit has a fighting chance of surviving another winter on Mars, if the weather and environment cooperate.
Plans for sol 1471 (Feb. 22, 2008) called for a test of the stability of Spirit's new perch prior to using the rock abrasion tool by having the rover touch the Martian surface with the Mössbauer spectrometer and apply 10 newtons of pressure (called a pre-load).
Sol-by-sol summary:
In addition to measurements of atmospheric dust levels with the panoramic camera and daily communications activities, which include morning direct-from-Earth uplinks over the rover's high-gain antenna and evening relays to Earth via the UHF antenna on the Mars Odyssey orbiter, Spirit completed the following activities:
Sol 1464 (Feb. 14, 2008): Spirit edged downslope another 4 centimeters (about 1.5 inches). The rover took thumbnail images of the sky for calibration purposes with the panoramic camera.
Sol 1465: Spirit took mid-field images and spot images of the sky for calibration purposes with the panoramic camera.
Sol 1466: Spirit acquired images for updating the rover's precise attitude relative to the Sun, surveyed the horizon and took spot images of the sky with the panoramic camera, and surveyed the external calibration target with the miniature thermal emission spectrometer.
Sol 1467: Spirit acquired images of the "El Dorado" dune field with the panoramic camera and snapped movie frames in search of dust devils with the navigation camera. The rover took thumbnail images of the sky with the panoramic camera.
Sol 1468: Spirit surveyed the sky at high Sun using the panoramic camera.
Sol 1469: Spirit surveyed the sky and ground with the miniature thermal emission spectrometer and took before-and-after stereo images with the navigation camera to enable the on-board visual odometry software to determine the rover's position. Spirit acquired a 5-by-1 mosaic of forward-looking images and a 5-by-1 mosaic of rearward-looking images with the navigation camera. Also with the navigation camera, the rover assessed atmospheric opacity caused by dust and scanned the sky for clouds.
Sol 1470 (Feb. 21, 2008): Spirit unstowed the robotic arm and moved it to test the rover's stability. Spirit measured atmospheric opacity caused by dust using both the panoramic and navigation cameras. The rover took spot images of the sky with the panoramic camera and surveyed the sky and ground with the miniature thermal emission spectrometer.
Odometry:
As of sol 1470 (Feb. 21, 2008), Spirit's total odometry was 7,528.07 meters (4.68 miles).
sol 1457-1463, Feb. 7-13, 2008: Spirit Inches Downward
Spirit is tiptoeing ever so carefully down the north edge of the elevated volcanic plateau known as "Home Plate." Having completed a 4-centimeter (1.6-inch) drive on sol 1463 (Feb. 13, 2008), the rover's current northerly tilt is 27.1 degrees. Spirit's handlers plan to have the rover drive another 4 centimeters on sol 1464 (Feb. 14, 2008).
They expect Spirit to be at the rover's final winter perch by the end of next week, following a few more 4-centimeter drives. Given recent progress, Spirit may achieve a northerly, Sun-facing tilt of 30 degrees, higher than originally anticipated. Spirit remains healthy.
Sol-by-sol summary:
In addition to measurements of atmospheric dust levels with the panoramic camera and daily communications activities, which include morning direct-from-Earth uplinks over the rover's high-gain antenna and evening relays to Earth via the UHF antenna on the Mars Odyssey orbiter, Spirit completed the following activities:
Sol 1457 (Feb. 7, 2008): Spirit surveyed the Martian sky and ground using the miniature thermal emission spectrometer, stowed the rover's robotic arm, and drove downslope.
Sol 1458: Spirit acquired images of the dune field known as "El Dorado," surveyed the Martian horizon, and took spot images of the sky for calibration purposes using the rover's panoramic camera. Spirit acquired movie frames in search of dust devils using the navigation camera.
Sol 1459: Spirit drove 12 centimeters (4.7 inches) further down the north edge of Home Plate. The rover surveyed the sky and ground with the miniature thermal emission spectrometer.
Sol 1460: Spirit surveyed the sky and ground using the miniature thermal emission spectrometer and took thumbnail images of the sky with the panoramic camera.
Sol 1461: Spirit acquired mid-field and far-field images using the panoramic camera.
Sol 1462: Spirit acquired a second set of mid-field images as well as thumbnail images of the sky using the panoramic camera.
Sol 1463 (Feb. 13, 2008): Spirit drove another 4 centimeters (1.6 inches) downslope. Using the panoramic camera, Spirit surveyed the horizon, monitored changes in the El Dorado dune field, and took spot images of the sky.
Odometry:
As of sol 1463 (Feb. 13, 2008), Spirit's total odometry was 7,528.01 meters (4.68 miles).
Spirit is healthy and all subsystems are operating as expected. Energy has been steady at about 260 watt-hours per Martian day, or sol (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). On Sol 1450 (Jan. 31, 2008), measurements of atmospheric opacity caused by dust -- known as Tau -- increased by 0.02 to 0.4, then fell back to 0.38, then drifted lower still to 0.333. Small changes such as these are typical of sol-by-sol variations during Martian fall and winter. As the atmosphere cleared, however, a different measurement known as the dust factor -- an estimate of the ability of sunlight to penetrate the layer of dust on the solar arrays -- also dipped slightly and continued to slowly decline, causing overall energy levels to remain about constant.
The dust factor is now 0.374, meaning that only about three-eighths of the sunlight reaching the arrays penetrates the dust layer to generate electricity. The dust factor continues to set new lows nearly every sol. The good news is that the decline has been slower than predicted, resulting in absolute values that are higher than predicted. The difference isn't great -- about 10 to 15 watt-hours, or enough energy to light a 15-watt sewing machine bulb for one hour -- but every bit is welcome.
Sol-by-sol summary:
In addition to receiving morning instructions directly from Earth via the high-gain antenna, measuring atmospheric dust levels with the panoramic camera, checking for drift (changes in time) in the miniature thermal emission spectrometer, and surveying the sky and ground with the miniature thermal emission spectrometer, Spirit completed the following activities:
Sol 1450 (Jan. 31, 2008): Spirit brushed the surface of the rock target known as "Freeman" (commemorating the Freeman Field Mutiny, a series of attempts in 1945 by African-Americans in the U.S. Air Force to integrate an all-white officers' club) using the wire brush on the rock abrasion tool. Spirit took high-resolution images with the navigation camera to verify on-board software measurements of rover slippage based on comparison of before-and-after stereo images of the terrain (the software is known as the visual odometry system). After communicating with the Odyssey orbiter, the rover acquired panoramic-camera images of the sunset.
Sol 1451: Spirit acquired data from a rock known as "Fuzzy Smith" using the miniature thermal emission spectrometer.
Sol 1452: Spirit took measurements of the external calibration target with the miniature thermal emission spectrometer and acquired a 2-by-2-by-5 mosaic of stereo microscopic images of the brushed surface of Freeman. The rover then placed the alpha-particle X-ray spectrometer on Freeman.
Sol 1453: Spirit took measurements of the external calibration target, a rock target known as "Winston_Gaskins3," and the background of Fuzzy Smith (the specific target was nicknamed "Fuzzy Smith bg2") using the miniature thermal emission spectrometer. After sending data to the Odyssey orbiter, Spirit spent about 6.3 hours integrating data from the brushed surface of Freeman with the alpha-particle X-ray spectrometer.
Sol 1454: Spirit took measurements of the external calibration target with the miniature thermal emission spectrometer.
Sol 1455: Spirit surveyed the external calibration target with the miniature thermal emission spectrometer and, after communicating with Odyssey, spent about 6.3 hours collecting additional data from Freeman with the alpha-particle X-ray spectrometer.
Sol 1456 (Feb. 6, 2008): Spirit took measurements of the external calibration target with the miniature thermal emission spectrometer. The following morning, the rover was to acquire full-color images, using all 13 filters of the panoramic camera, of a rock target known as "Samuel_Hughes."
Odometry:
As of sol 1455 (Feb. 5, 2008), Spirit's total odometry remained at 7,527.83 meters (4.68 miles).
sol 1445-1449, Jan. 26-30, 2008: Spirit Takes Steps to Conserve Energy During Martian Winter
Spirit is responding to declining winter power levels by dipping into the batteries on one sol (Martian day), then recharging them on the next. In addition, one of the first things the rover did to conserve energy was eliminate afternoon data transfers to the Odyssey orbiter on days when the batteries were being recharged. Though this approach meant the rover wouldn't be able to send data on those sols, it saved enough energy to be worth the sacrifice. As Martian winter deepens, it's possible that, as the Opportunity rover did during the depth of the dust storm a few months ago, Spirit will use only every third Odyssey pass or adopt even more stringent power-conserving measures.
Meanwhile, Spirit remains healthy. For the most part, all subsystems are performing as expected. Energy has been holding steady in the range of 260 watt-hours. Tau (atmospheric opacity) continues to decline slightly, but the dust factor (the ability of sunlight to penetrate dust on the solar panels) also continues to decline slightly.
The winter Sun continues to dip lower in the sky. As of sol 1450 (Jan. 31, 2008), the noontime Sun was 64.6 degrees above the northern horizon, indicating that the optimal northern tilt of the rover deck would be 25.4 degrees from vertical (90 - 64.6 = 25.4). Spirit's current northward tilt is 22 degrees, relatively close to optimal. By mid-February, the optimal tilt will increase to about 28 degrees, the maximum Spirit is anticipated to be able to achieve. That's about the time when rover drivers plan to have the rover complete one more short drive to get into position for the winter.
The orbiting Odyssey spacecraft continues to provide a relay from the rovers to Earth. Each rover sends data to Odyssey via a UHF link. (UHF is "Ultra High Frequency" and represents the same band of frequencies used by the UHF channels on a TV set, channels 14-83, which transmit signals at roughly 400-500 megahertz.) Odyssey stores the data until it can transmit it to Earth using the X-band link. X-band is a microwave frequency that operates at roughly 7-8 gigahertz (megahertz and gigahertz refer, respectively, to millions of cycles per second and billions of cycles per second).
Originally, the Mars rover mission was intended to be an X-band mission, with the rovers using their X-band transmitters to return data directly to Earth. The UHF radio was intended to serve as a backup. But because relay operations via Odyssey proved wildly successful, Odyssey became the preferred avenue for returning data. For one thing, the UHF link can accommodate data at either 128 kilobits per second or 256 kilobits per second (in these cases, "kilo" actually means 1,024 rather than the usual 1,000). The highest X-band data rate for the rovers is only 28.4 kilobits per second, and most of the time, even that rate is unachievable. Odyssey, however, can return data at up to 124.4 kilobits per second using the X-band link. In fact, the lowest rate of data transmission from Odyssey is the same as the highest rate for the rovers.
During the past week, Spirit twice conducted a "grind scan" procedure with the rock abrasion tool. After the tool's encoder failed some time ago, engineers redesigned how the tool is used. Part of that redesign includes doing a "scan" before the rover grinds or brushes any surface (except, of course, that Spirit is no longer grinding into rock surfaces -- after performing more than 10 times longer than expected and contributing a great deal of science data to the mission, the grind bit wore out.)
During the "scan" procedure, the rover pushes the brush and bit into a targeted surface until it measures an increase in electrical current, which implies contact with the rock surface. Detecting the exact location of a possibly irregular surface is important for safely operating the rock abrasion tool.
The only reason Spirit is using the rock abrasion tool at this time is that the rover has moved to a new location as of sol 1440 (Jan. 21, 2008). As Spirit inches down the north-facing slope of "Home Plate," the rover will sample each new location for insight into how the rocks change and how Home Plate was formed.
As Spirit is stationed on a fairly steep slope, engineers have been concerned that moving the robotic arm might cause the rover to slip. The arm is very light and represents only a percent or two of Spirit's weight, but on a slope, it's always possible that even a slight shift could cause a slide. On top of that, the "grind scan" function requires the rover to press down on ("preload") the target. The pressure isn't much, only 15 newtons (not quite 3.5 pounds), but that, too, could conceivably cause a slip. The rover's handlers have created a plan that includes some safety checks.
The first time around, based on receipt of erroneous data, they had to double-check that the slope beneath the rover didn't exceed 20 degrees, the maximum slope previously allowed. Because Spirit was already tilted 22.4 degrees, the safety check tripped immediately and the rover did not conduct any of the planned activities with the rock abrasion tool. Rover handlers re-planned the activities and successfully completed the "scan" procedure on sol 1448 (Jan. 29, 2008).
The next step will be to actually brush the surface. But that's a story for another week.
Sol-by-sol summary:
In addition to receiving morning instructions directly from Earth via the high-gain antenna, measuring atmospheric dust levels with the panoramic camera, and checking for drift (changes in time) in the miniature thermal emission spectrometer, Spirit completed the following activities:
Sol 1445 (Jan. 26, 2008): Spirit conducted a grind scan procedure at a target called "Freeman." Spirit took high-resolution images with the navigation camera to verify on-board software measurements of rover slippage based on comparison of before-and-after stereo images of the terrain (the software is known as the visual odometry system).
Sol 1446: Spirit re-took part 12 of a mosaic of images of the rover deck and took thumbnail images of the sky with the panoramic camera. The rover acquired data from rock targets known as "Fuzzy_Smith_2" and "Winston_Gaskins_2" using the miniature thermal emission spectrometer.
Sol 1447: Spirit monitored dust accumulation on the rover mast, completed a survey of rock clasts with the panoramic camera, and surveyed the external calibration target, the sky, and the ground with the miniature thermal emission spectrometer.
Sol 1448: Spirit took spot images of the sky and surveyed the horizon with the panoramic camera and scanned the sky for clouds with the navigation camera. The rover monitored changes in the distant dune field known as "El Dorado" with the panoramic camera. Spirit conducted a grind scan at Freeman with the rock abrasion tool. Spirit took high-resolution images with the navigation camera to verify on-board software measurements of rover slippage based on comparison of before-and-after stereo images of the terrain.
Sol 1449: (Jan. 30, 2008): Spirit surveyed the sky and ground with the miniature thermal emission spectrometer and acquired movies in search of dust devils using the navigation camera. The following day, plans called for the rover to survey the external calibration target using the miniature thermal emission spectrometer.
Odometry:
As of sol 1448 (Jan. 29, 2008), Spirit's total odometry remained at 7,527.83 meters (4.68 miles).
sol 1437-1444, Jan. 18-25, 2008: Atmospheric Dust Levels Decline Slightly for Spirit
Spirit received some welcome news, as atmospheric dust levels decreased slightly, enabling power levels to remain fairly steady at 260 watt-hours to 270 watt- hours, even as the Martian sun continued to sink toward the northern horizon. (One hundred watt-hours is the amount of energy needed to light a 100-watt bulb for one hour.) Tau measurements of atmospheric opacity decreased from 0.44 to 0.36. The dust factor -- representing the fraction of predicted solar power actually generated after blocking of sunlight by dust on the solar panels -- was nearly steady, declining only 0.05 from 0.39 to 0.385.
Spirit remained perched on the north edge of "Home Plate," a slightly bowl-shaped surface feature with a raised rim that, along its northern edge, is roughly 2 meters (6 feet) above the surrounding area. Directly below Spirit, the slope is about 28 degrees. As Martian winter approaches and the Sun gets lower and lower in the sky, engineers will direct Spirit farther and farther down the slope, increasing the rover's tilt to follow the sun.
As of Sol 1444 (Jan. 25, 2008), Spirit's 22.4-degree northerly tilt was almost perfectly matched to the position of the Sun, which is about 22 degrees below the zenith (the point in the Martian sky directly above the rover). In roughly two to three weeks, Spirit will be adjusted to a final winter position with an expected tilt of about 28 degrees to the north. This will be the best Spirit can do, given the absence of steeper slopes in the vicinity. Even if there were steeper slopes nearby, safety concerns would probably preclude their use.
With more dust on the solar arrays than ever before in the mission, Spirit's third winter will be especially challenging. Estimates indicate that at the winter solstice, the point where the noontime sun will be lowest in the sky, Spirit's energy production will be near the edge of survival. But with Tau and dust accumulation both slightly better than expected and with careful management, the rover's handlers are hopeful that Spirit will ride out the winter and begin roving again in the spring.
While parked for the winter, Spirit will not be idle. Except for the period of very lowest power, the rover will be studying the atmosphere, watching for clouds, monitoring the dust accumulation, checking for frost, and surveying the immediate surroundings, along with completing other tasks.
One of the ways the rover maximizes efficiency is by replacing a large amount of redundant data with a smaller amount of data. This is known as image compression. A simple, everyday analogy is multiplication, in which the mathematical operation, (5 * 4), takes fewer characters than (4 + 4 + 4 + 4 + 4). The rover uses a process called lossless compression, or LOCO for short. There are two classes of compression, lossless and lossy. Lossy compression is sort of like standard television, producing images that are usually sufficient. Lossless compression is analogous to high-definition television and is used for a few images that need to be mathematically processed to include all the detail the cameras can capture. For Spirit, lossless compression is particularly important for collecting detailed images of the area in front of the rover directly after moving to a new location. It is used to generate maps of surfaces reachable with the robotic arm and each of the instruments, called "reachability maps," as well as mathematical models of the area around the rover that are used to simulate the rover's motion during planning, called "terrain meshes." Lossless compression is also used to create slope maps that show steepness and orientation toward the Sun.
Sol-by-sol summary:
In addition to receiving morning instructions directly from Earth via the high-gain antenna and measuring atmospheric dust levels with the panoramic camera, Spirit completed the following activities:
Sol 1437 (Jan. 18, 2008): Spirit communicated with the Odyssey orbiter while surveying the background of the rock known as "Fuzzy Smith" with the miniature thermal emission spectrometer.
Sol 1438: Spirit surveyed the sky and ground with the miniature thermal emission spectrometer, surveyed the horizon with the panoramic camera, and checked for drift -- changes with time -- in the miniature thermal emission spectrometer.
Sol 1439: Spirit acquired full-color images of the external dust capture magnets using all 13 filters of the panoramic camera, took spot images of the sky with the panoramic camera, and checked for drift in the miniature thermal emission spectrometer. The rover studied Fuzzy Smith and a rock known as "Winston Gaskins" with the miniature thermal emission spectrometer.
Sol 1440: Spirit acquired several panoramic camera images of the rover deck, scanned the sky for clouds with the navigation camera, and took spot images of the sky with the panoramic camera. The rover checked for drift in the miniature thermal emission spectrometer and adjusted position to achieve a greater northerly tilt. After adjusting position, Spirit took images with the hazard avoidance cameras and a single-frame LOCO image with the navigation camera.
Sol 1441: Spirit surveyed the horizon with the panoramic camera, surveyed the external calibration target with the miniature thermal emission spectrometer, and watched for dust devils. The rover also checked for drift in the miniature thermal emission spectrometer.
Sol 1442: Spirit acquired a 1-by-1 panoramic camera mosaic of the work volume reachable with the robotic arm and took thumbnail images of the sky with the panoramic camera. Spirit checked for drift in the miniature thermal emission spectrometer, unstowed the robotic arm, acquired diagnostic images of the rock abrasion tool with the hazard avoidance and panoramic cameras, and exchanged tools to the alpha-particle X-ray spectrometer. The rover sent data to Odyssey during the overhead pass of the orbiter.
Sol 1443: Spirit acquired a 5-by-1 standard tier of images as well as a 5-by-1, rearward-looking mosaic of images with the navigation camera. The rover conducted a horizon survey and acquired more images of the rover deck with the panoramic camera. Spirit checked for drift in the miniature thermal emission spectrometer, communicated with the Odyssey orbiter, and spent 6.75 hours acquiring data with the alpha-particle X-ray spectrometer.
Sol 1444 (Jan. 25, 2008): Spirit surveyed the sky at high Sun with the panoramic camera and checked for drift in the miniature thermal emission spectrometer. The following morning, the rover was to scan the sky for clouds with the navigation camera and take spot images of the sky with the panoramic camera.
Odometry:
As of sol 1444 (Jan. 25, 2008), Spirit's total odometry was 7,527.83 meters (4.68 miles).
sol 1430-1436, Jan. 11-17, 2008: Spirit Continues to Increase Northerly Tilt
Spirit is currently engaged in a campaign of short bumps -- adjustments in position -- that will incrementally increase the rover's northerly tilt to 22 degrees and eventually to 29 degrees by month's end. Spirit is healthy and all subsystems are operating as expected. The latest power levels measured on sol 1436 (Jan. 17, 2008) were 261 watt-hours (by definition, 100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour).
After successfully adjusting position on sol 1429 (Jan. 9, 2008) to achieve a northerly tilt of about 16 degrees, Spirit completed scientific studies of the rock target known as "Chanute." From sols 1431-1433 (Jan. 12-14, 2008), Spirit acquired a microscopic image mosaic of the brushed surface, placed the alpha-particle X-ray spectrometer on the target, and collected compositional data for about six hours. Sol 1433 was a recharge sol with no UHF-band communication. After reviewing the data, scientists agreed there was too much dust and debris in the alpha-particle X-ray spectrometer measurements. They thus decided to move the instrument to a "cleaner" location in the activity plan for sols 1434-1435 (Jan. 15-16, 2008) and collect another six hours worth of data. They documented the new site with a single-frame microscopic image.
Following sol 1435, also a recharge sol with no UHF communication, the rover's handlers planned another bump on sol 1436 (Jan. 17, 2008). Because of power limitations, they delayed a plan to inspect some strange-appearing brush patterns that may indicate normal brush wear or possible damage. They planned to use the miniature thermal emission spectrometer on sol 1437 (Jan. 18, 2008) at the start of a three-part imaging campaign on a rock known as "Fuzzy Smith."
Spirit's bump on sol 1436 was successful and put the rover at a new northerly tilt of approximately 18 degrees. The impact on power will not be known until receipt of data on sol 1437. The science team's goal is to achieve a northerly tilt of 22 degrees as soon as possible, at which point they will likely pause to perform scientific studies of a new target.
Sol-by-sol summary:
In addition to receiving morning instructions directly from Earth via the high-gain antenna, Spirit completed the following activities:
Sol 1430 (Jan. 11, 2008): Spirit monitored atmospheric dust with the panoramic camera.
Sol 1431: Spirit took full-color images of Chanute using all 13 filters of the panoramic camera. The rover monitored atmospheric dust, unstowed the robotic arm, and acquired navigation camera images. Spirit acquired a 2-by-2-by-5 mosaic of stereo microscopic images of the brushed surface of Chanute and placed the alpha-particle X-ray spectrometer on the target. The rover took images following instrument placement with the navigation camera.
Sol 1432: Spirit measured atmospheric opacity caused by dust with the panoramic and navigation cameras and scanned the sky for morning clouds with the navigation camera. The rover acquired compositional data from the brushed surface of Chanute with the alpha-particle X-ray spectrometer.
Sol 1433: Spirit monitored atmospheric dust levels using the panoramic and navigation cameras and scanned the sky for clouds with the navigation camera.
Sol 1434: Spirit measured atmospheric dust with the panoramic and navigation cameras and scanned the sky for clouds with the navigation camera. The rover acquired a 1-by-1-by-1 mosaic and a 1-by-1-by-3 mosaic of microscopic images of the brushed surface of Chanute and placed the alpha-particle X-ray spectrometer on the target. Spirit acquired navigation camera images after placing the spectrometer on the target. The rover communicated with the Odyssey orbiter and acquired data from the brushed target with the alpha-particle X-ray spectrometer.
Sol 1435: Spirit measured atmospheric dust opacity with the panoramic camera and acquired a 5-by-1 mosaic of navigation camera images of the rover deck, a 2-by-1 mosaic of panoramic camera images, and two views of the rover deck with the panoramic camera.
Sol 1436 (Jan. 17, 2008): Spirit took thumbnail images of the sky with the panoramic camera, meaasured atmospheric dust with the panoramic camera, took images of the brush on the rock abrasion tool, and bumped into a new position to increase northerly tilt. The rover took images with the hazard avoidance and navigation cameras after the bump. Spirit also acquired navigation camera images of Fuzzy Smith after the bump. The rover took a 1-by-1 image mosaic of the work volume with the panoramic camera. The following day's plans called for Spirit to measure atmospheric dust with the panoramic camera, monitor dust accumulation on the rover mast, and acquire additional images of the rover deck as well as spot images of the sky with the panoramic camera.
Odometry:
As of sol 1436 (Jan. 17, 2008), Spirit's total odometry was 7,527.71 meters (4.68 miles).
sol 1423-1429, Jan. 3-9, 2008: Spirit Tilts Toward the Sinking Sun
After directing the rover to brush the surface of the rock target known as "Chanute," engineers placed continued studies on hold while they adjusted Spirit's position to achieve a greater northerly tilt, in the direction of the sinking winter Sun. The latest available power levels measured on sol 1429 (Jan. 9, 2008) were 268 watt-hours, a sobering reminder of the onset of winter. Spirit was in the middle of a campaign of scientific studies with the brush on the rock abrasion tool, alpha-particle X-ray spectrometer, and microscopic imager. The move was successful and gave the rover a new northerly tilt of about 16 degrees.
Spirit is healthy and all subsystems are nominal.
After Spirit had completed acquisition of the "Tuskegee panorama" on sol 1423 (Jan. 3, 2008), planned science activities included brushing the surface of Chanute prior to continued investigation with the alpha-particle X-ray and Mössbauer spectrometers. To locate the surface, the rover performed a "seek scan" with the rock abrasion tool on sol 1424 (Jan. 4, 2008). This activity is a work-around procedure that compensates for a broken encoder and allows the rover to stall the motor of the rock abrasion tool when it makes contact with the surface.
The next two Martian days were recharge sols. Spirit brushed the surface of Chanute on sol 1427 (Jan. 7, 2008). This was also followed by another recharge sol. The rover's handlers then made two significant changes to the strategic plan to address the deteriorating power situation. First, because recharge sols were becoming less and less effective, they decided to begin deleting the UHF passes on these sols, starting on sol 1428 (Jan. 8, 2008). Second, they decided to proceed sooner than anticipated with plans to achieve a steeper northerly tilt of 20 degrees. Activities on sol 1429 (Jan. 9, 2008) involved a bump of 10 centimeters (4 inches) downslope. Sol 1430 (Jan. 11, 2008) was to be a recharge sol with no UHF.
The impact of the new, 16-degree northerly tilt on power will not be known until receipt of further data on sol 1431 (Jan. 12, 2008). The science team's goal is to reach 20 degrees as soon as possible, meaning they will likely execute additional short bumps similar to those of sol 1429 in the very near future. In the meantime, Spirit will complete work on Chanute.
Sol-by-sol summary:
In addition to receiving morning instructions directly from Earth via the high-gain antenna, sending data to Earth at UHF frequencies via the Odyssey orbiter, and measuring atmospheric dust levels, Spirit completed the following activities:
Sol 1423 (Jan. 3, 2008): Spirit acquired a 2-by-1 mosaic of the Tuskegee panorama.
Sol 1424: Spirit acquired a 4-by-1 mosaic of the Tuskegee panorama, performed a seek-scan maneuver to locate the surface of Chanute with the rock abrasion tool, and took navigation camera images following the procedure.
Sol 1425: Spirit acquired a 4-by-1 mosaic of the Tuskegee panorama.
Sol 1426: Spirit acquired morning thumbnail images of the sky with the panoramic camera.
Sol 1427: Spirit acquired spot images of the sky with the panoramic camera, monitored dust on the panoramic camera mast assembly, and scanned the sky for clouds with the navigation camera. The rover brushed the surface of Chanute, stowed the robotic arm, and acquired navigation camera images of the brushed surface.
Sol 1428: Spirit acquired a 4-by-1 mosaic of images of the Tuskegee panorama.
Sol 1429 (Jan. 9, 2008): Spirit surveyed the sky at low Sun with the panoramic camera, bumped downslope, took images with the hazard avoidance cameras, and acquired a navigation camera image after the change in position. The following day's plans called for the rover to survey the horizon with the panoramic camera and acquire movie frames in search of dust devils spaced at 8-minute intervals using the navigation camera.
Odometry:
As of sol 1429 (Jan. 9, 2008), Spirit's total odometry remained at 7,527.52 meters (4.68 miles).
Four years ago on Jan. 4 (Pacific time), Spirit landed on the surface of Mars, in search of habitable environments. Now the rover is facing perhaps its greatest challenge so far -- surviving the third winter on Mars with substantial amounts of dust from last year's global storms on the solar arrays. As of sol 1406 (Dec. 17, 2007), the solar arrays were about 60 percent obscured by dust (a dust factor of 0.4), the most obscuration ever. By the time of the winter solstice on sol 1593 (June 26, 2008), the solar arrays are expected to be about 70 percent obscured (a dust factor of 0.3).
To increase Spirit's chances of survival, engineers have positioned the rover on a steep, north-facing slope to maximize exposure to sunlight. Still, even with an expected north-facing tilt of greater than 25 degrees, Spirit will likely need more energy than available each sol without additional changes, according to Project Manager John Callas. These changes may include disabling the survival heater on the miniature thermal emission spectrometer, putting the instrument at risk, and disabling the survival heater of the rover's electronic module. The module was successfully tested down to minus 55 degrees C. using brand-new electronics; disabling the heater would likely result in temperatures dipping below minus 40 degrees C., a significant dip given that the rover has now completed more than 1,400 thermal cycles.
Other survival strategies include tightly managing Spirit's energy budget each sol and minimizing operating time and communication sessions. During the darkest days of winter, Spirit may spend months facing the risk of low-power faults, when the rover takes the batteries off-line and goes to sleep due to inadequate power levels.
Meanwhile, Spirit remains healthy and all subsystems are operating as expected. The rover continues to study a rock feature dubbed "Chanute," so far gathering more than 60 hours of data about iron-bearing minerals using the Mössbauer spectrometer. Energy is around 255 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). As of sol 1421 (Jan. 1, 2008), atmospheric dust levels, known as Tau, were at 0.487 and the dust factor was at 0.49.
Sol-by-sol summary:
In addition to receiving morning instructions directly from Earth via the high-gain antenna, sending data to Earth at UHF frequencies via the Odyssey orbiter, and measuring atmospheric dust levels, Spirit completed the following activities:
Sol 1416 (Dec. 27, 2007): Spirit re-started the Mössbauer spectrometer and spent 23 hours integrating data from Chanute with the instrument. The rover acquired panoramic camera images of the dune field known as "El Dorado."
Sol 1417: Spirit acquired a 4-by-1 mosaic of the so-called "Tuskegee panorama," monitored dust accumulation on the panoramic mast assembly, and re-started the Mössbauer spectrometer for 5 hours of data integration from Chanute.
Sol 1418: Spirit acquired another 4-by-1 mosaic of the Tuskegee panorama, followed by a 2-by-1 mosaic.
Sol 1419: Spirit acquired a 4-by-1 mosaic of the Tuskegee panorama and re-started the Mössbauer spectrometer for 5 hours of data collection from Chanute. The rover watched for dust devils and acquired another 4-by-1 mosaic of the Tuskegee panorama.
Sol 1420: Spirit re-started the Mössbauer spectrometer and acquired 4 hours worth of data from Chanute with the instrument. After communicating with the Odyssey spacecraft, Spirit acquired new measurements of atmospheric dust levels.
Sol 1421: Spirit acquired a 4-by-1 and a 2-by-1 mosaic of the Tuskegee panorama.
Sol 1422 (Jan. 2, 2008): Spirit acquired a 4-by-1 mosaic of the Tuskegee panorama, re-started the Mössbauer spectrometer, and spent 4 hours studying Chanute with the instrument. The rover acquired a 2-by-1 and a 4-by-1 mosaic of the Tuskegee panorama.
Odometry:
As of the rover's last drive on sol 1406 (Dec. 17, 2007), Spirit's total odometry was 7,527.52 meters (4.68 miles).
Spirit is tilted about 13 degrees to the north at a site known as "WinterHaven 3" on the northern edge of "Home Plate." During the holidays, Spirit performed studies of a rock feature called "Chanute" with instruments on the robotic arm, including the microscopic imager, alpha-particle X-ray spectrometer, and Mössbauer spectrometer. In addition, Spirit has been acquiring a panoramic view of "Home Plate" known as the "Tuskegee panorama."
Energy is currently around 277 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for 1 hour), with Tau measurements of atmospheric dust opacity at 0.502 and a dust factor of 0.4008 as of sol 1414 (Dec. 25, 2007).
Sol-by-sol summary
In addition to receiving morning instructions directly from Earth via the high-gain antenna and sending data to Earth at UHF frequencies via the Odyssey orbiter, Spirit completed the following activities:
Sol 1409 (Dec. 20, 2007): Spirit unstowed and extended the robotic arm to test its stability, acquired a 2-by-2-by-5 mosaic of microscopic images, and placed the alpha-particle X-ray spectrometer on target. The rover acquired documentation imaging of the robotic arm with the navigation camera and took panoramic camera images of the rover's tracks as well as a rock known as "Fuzzy Smith," which the rover first encountered on approaching Home Plate in 2006.
Sol 1410: Spirit scanned the sky and ground with the miniature themal emission spectrometer and integrated data from Chanute using the alpha-particle X-ray spectrometer.
Sol 1411: Spirit switched tools on the robotic arm from the alpha-particle X-ray spectrometer to the Mössbauer spectrometer using visual odometry software, collected data from Chanute with the Mössbauer spectrometer, and surveyed the horizon and took spot images of the sky with the panoramic camera.
Sol 1412: Spirit measured atmospheric dust levels with the panoramic camera, re-started the Mössbauer spectrometer for additional integration of data from Chanute, and acquired part of the Tuskegee panorama.
Sol 1413: In the morning, Spirit continued work on the Tuskegee panorama, monitored atmospheric dust levels with the panoramic camera, and re-started the Mössbauer spectrometer for continued study of Chanute.
Sol 1414: Spirit acquired additional frames of the Tuskegee panorama, measured atmospheric dust with the panoramic camera, and re-started the Mössbauer spectrometer for additional integration of data from Chanute.
Sol 1415 (Dec. 26, 2007): Spirit surveyed the morning sky, measured atmospheric dust, took spot images of the sky, and completed a sky survey at high Sun with the panoramic camera.
Odometry
As of sol 1414 (Dec. 25, 2007), Spirit's total odometry was about 7,527 meters (4.7 miles).sol 1404-1408, December 21, 2007: Spirit Makes It to a North-Facing Slope
Spirit has achieved 13 degrees of northerly tilt after backing the rear and middle wheels over the north edge of "Home Plate," where the rover will remain during the coming holidays. Power levels have already increased significantly from 260 watt-hours on sol 1404 (Dec. 15, 2007) to 291 watt-hours on sol 1408 (Dec. 19, 2007).
Spirit's ideal northerly tilt at present would be 16 degrees, and the rover's handlers plan to have the rover creep farther down the slope in mid-January to increase the northerly tilt. On Spirit's current track, they expect to see an ultimate northerly tilt of 25 degrees to 30 degrees.
In the meantime, Spirit will perform studies using instruments on the rover's robotic arm, including the microscopic imager, alpha-particle X-ray spectrometer, and Mössbauer spectrometer. Spirit's handlers still have a huge challenge ahead, but after three weeks of working on Mars time and on weekends, they are, like the rover, enjoying a long-awaited and well-deserved sigh of relief.
The science team is nicknaming features in the area after the Tuskegee Airmen, the first black pilots to serve in the U.S. military.
Sol-by-sol summary:
In addition to receiving morning instructions directly from Earth via the high-gain antenna, sending evening data to Earth at UHF frequencies via the Odyssey orbiter, and measuring atmospheric dust levels with the panoramic camera, Spirit completed the following activities:
Sol 1404 (Dec. 15, 2007): Spirit drove to the rover's last perch before descending over the north edge of Home Plate.
Sol 1405: Spirit acquired images with the navigation camera, drove the rear wheels over the rim, and acquired post-drive images with the navigation camera.
Sol 1406: Spirit drove the middle wheels over the rim of Home Plate and acquired post-drive images with the navigation camera.
Sol 1407: Spirit acquired a "quick fine attitude," a calibration activity to compensate for changes in time in the inertial measurement unit. Spirit acquired a 360-degree panorama of images with the navigation camera, images with the front and rear hazard avoidance cameras, and spot images of the sky with the panoramic camera.
Sol 1408 (Dec. 19, 2007): Spirit acquired full-color images, using all 13 filters of the panoramic camera, of the work volume reachable by instruments on the rover's robotic arm. The rover completed a survey at high sun with the panoramic camera.
Odometry:
As of sol 1408 (Dec. 19, 2007), Spirit's total odometry was 7527.52 meters (4.6 miles).
sol 1398-1403, December 17, 2007: Final Winter Haven Selection Near
To make the most of waning sunlight during the approach of Martian winter, Spirit's handlers have returned to "Mars time." This means their working hours coincide with the Martian day, as they did for the first three months after the rover landed on the red planet. Because a Martian day is about 40 minutes longer than an Earth day, Mars time can coincide with all hours of the day and night on Earth. The alarm might go off the same time one day, 40 minutes later the next day, an hour and 20 minutes later the next day, and so on.
Spirit's solar power levels continue to drop, with solar array energies recently ranging from 293 watt-hours to 254 watt-hours, depending on the vehicle's orientation relative to the Sun. (One hundred watt-hours is the amount of energy needed to light a 100-watt bulb for one hour.)
All members of the rover science team -- drivers, engineers, and scientists -- are evaluating data to select a place where the rover will attempt to survive another Martian winter, focusing on areas that will tilt the rover's solar panels to the north more than 25 degrees. They will select a final location from a narrowed list of choices based on proximity to the rover's current position and the characteristics of the terrain, with an eye for accessibility as well as continued exploration in the spring.
Spirit reached the northern edge of "Home Plate" after driving 13.24 meters (43.44 feet) on Martian day, or sol, 1397 (Dec. 8, 2007). Three Martian days later, on sol 1400 (Dec. 11, 2007), Spirit finished collecting reconnaissance images of the northern exposure of the elevated plateau.
During the past week, rover planners got a special visit from two Tuskegee Airmen, the first black pilots to serve in the U.S. military. The pilots shared stories about serving in World War II while learning about rover operations.
Sol-by-sol summary:
In addition to receiving morning instructions directly from Earth via the high-gain antenna, sending evening data to Earth at UHF frequencies via the Odyssey orbiter, and measuring atmospheric dust levels with the panoramic camera, Spirit completed the following activities:
Sol 1398 (Dec. 9, 2007): Spirit drove 6.5 meters (21.3 feet) in a path nearly parallel to the northern edge of Home Plate. The rover acquired post-drive images with the hazard avoidance cameras and a mosaic of images with the navigation camera.
Sol 1399: Spirit drove 7.19 meters (23.6 feet) toward a small promontory to acquire images of the slopes below. The rover acquired post-drive images with the hazard avoidance cameras and a mosaic of images with the navigation camera. The following morning, Spirit acquired a series of navigation camera images to complete a 360-degree view of the rover's location after completing the drive.
Sol 1400: Spirit nudged 0.75 meter (2.5 feet) closer to the edge of Home Plate for a better view of what lay below. The rover acquired post-drive images with the hazard avoidance cameras and a mosaic of images with the navigation camera.
Sol 1401: Spirit took a break from driving and acquired images with the panoramic camera before turning around to back down the steep slope where the rover will spend the winter. After turning, the rover's solar arrays blocked the view of the slope by cameras on the rover mast assembly. Following the maneuver, Spirit acquired two image mosaics with the panoramic camera.
Sol 1402: Spirit acquired a pre-drive image of a pointy rock known as "General B.O. Davis" before backing up 2.5 meters (8.2 feet) and turning 180 degrees. The rover acquired post-drive images using the hazard avoidance cameras and a mosaic of images using the navigation camera. The following morning, Spirit monitored dust on the panoramic camera mast assembly and completed a systematic ground survey and a survey of rock clasts with the panoramic camera.
Sol 1403 (Dec. 14, 2007): Plans called for Spirit to approach the edge of Home Plate backward and acquire post-drive images with the hazard avoidance cameras as well as an image mosaic with the panoramic camera.
Odometry:
As of sol 1402 (Dec. 13, 2007), Spirit's total odometry was 7523.31 meters (4.67 miles).
sol 1390-1397, December 14, 2007: Spirit Scouts "Home Plate" for Safe Haven
Spirit has arrived at the north edge of "Home Plate." The rover will spend the next few Martian days, or sols, scouting the edge of Home Plate and acquiring images of the slopes to determine the best site for "Winter Haven 3," where Spirit will try to survive another season of minimal sunlight. Once the team selects a site, Spirit will drive down the north-facing edge of Home Plate and maneuver into position to achieve the highest northerly tilt possible.
Power levels are dropping rapidly, partly because the sun continues its retreat north on its way to winter solstice, and partly because the landscape tilts slightly southward near the rim. Drive sols are so precious and few, the team has been working long hours and weekends to make the most of the remaining sunlight.
Sol-by-sol summary:
In addition to receiving morning instructions directly from Earth via the high-gain antenna, sending evening data to Earth at UHF frequencies via the Odyssey orbiter, and measuring atmospheric dust levels with the panoramic camera, Spirit completed the following activities:
Sol 1390 (Nov. 30, 2007): Spirit drove in search of Winter Haven 3 and acquired post-drive images with the navigation camera. Spirit acquired full-color images, using all 13 filters of the panoramic camera, of the low, sandy area nicknamed "Tartarus." The rover surveyed Tartarus with the miniature thermal emission spectrometer and surveyed the horizon with the panoramic camera.
Sol 1391: Spirit continued to drive in search of Winter Haven 3 and acquire post-drive images with the navigation camera. The rover assessed atmospheric opacity caused by suspended dust with the navigation camera. Spirit acquired a mosaic of images with the panoramic camera and monitored dust accumulation on the rover mast assembly.
Sol 1392: Spirit drove in search of Winter Haven 3 and acquired a post-drive image mosaic and a rearward-looking image mosaic with the navigation camera.
Sol 1393: Spirit continued to drive in search of Winter Haven 3. Spirit acquired a post-drive image mosaic and a rearward-looking image mosaic with the navigation camera. The rover also completed a survey of rock clasts and a systematic ground survey with the panoramic camera.
Sol 1394: Spirit drove in search of Winter Haven 3 and acquired post-drive and rearward-looking image mosaics with the navigation camera. Spirit also acquired an image mosaic of Home Plate with the panoramic camera.
Sol 1395: Spirit drove in search of Winter Haven 3 and acquired post-drive images with the navigation camera. Spirit acquired a mosaic of panoramic camera images of a target known as "Hummock" and a rearward-looking mosaic of navigation camera images.
Sol 1396: Spirit continued driving in search of Winter Haven 3. The rover acquired post-drive and rearward-looking image mosaics with the navigation camera. Spirit completed a survey of rock clasts and a systematic ground survey with the panoramic camera.
Sol 1397 (Dec. 8, 2007): Plans called for Spirit to continue driving in search of Winter Haven 3, acquire post-drive images with both the navigation and panoramic cameras, and conduct a systematic ground survey as well as acquire spot images of the sky with the panoramic camera.
Odometry:
As of sol 1397 (Dec. 8, 2007), Spirit's total odometry was 7495.15 meters (4.66 miles).
sol 1384-1389, November 30, 2007: Spirit Breaks Free in Race for Survival
In typical unflagging fashion, Spirit has managed to break free of piles of soil built up around the wheels in a low, sandy area that the rover's handlers have nicknamed "Tartarus," after a deep, underworld dungeon in Greek mythology. Team members are pulling out all the stops to get Spirit to a winter location where, based on solar power projections, the rover has a chance at survival.
As the crow flies, that spot is about 25 meters (82 feet) away. During the next few weeks, Spirit's journey to "Winter Haven 3" is expected to be no less difficult, requiring the rover to maneuver across a sandy, rocky valley along the western edge of "Home Plate."
During Spirit's 14 Martian days in Tartarus, the rover's trials were reminiscent of those of the previous Martian winter, when Spirit spent 12 sols churning up white material in a sandy area while trying to reach the slopes of "McCool Hill."
Guided by experienced, interplanetary drivers, the robotic geologist Spirit escaped Tartarus on sol 1388 (Nov. 28, 2007) and drove 3.43 meters (11.3 feet). This was a significant distance, given that Spirit's previous two drives were measured in centimeters (inches). The drive took the rover south away from Tartarus to look for another path around the area before driving north once again.
Spirit's handlers will be working non-stop during the weekend to take advantage of seasonal sunlight available for driving before solar power levels drop further. At present, the rover has about 310 watt-hours of power each day (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour).
Sol-by-sol summary:
In addition to receiving morning instructions directly from Earth via the high-gain antenna, sending evening data to Earth at UHF frequencies via the Odyssey orbiter, and measuring atmospheric dust levels with the panoramic camera, Spirit completed the following activities:
Sol 1384 (Nov. 24, 2007): Spirit managed to drive 6.98 meters (22.9 feet). The rover took post-drive images with the hazard avoidance cameras and a mosaic of images with the navigation camera. The next morning, Spirit measured atmospheric dust with the navigation camera and surveyed the sky and ground with the miniature thermal emission spectrometer.
Sol 1385: Spirit spent the day recharging the battery. The following morning, Spirit acquired movie frames in search of dust devils with the navigation camera and completed a survey of rock clasts with the panoramic camera.
Sol 1386: Spirit drove only 0.25 meters (10 inches) and took images with the hazard avoidance cameras. The following morning, the rover acquired full-color images of Tartarus using all 13 filters of the panoramic camera.
Sol 1387: Spirit drove only 0.14 meter (5.5 inches) and acquired post-drive images with the navigation camera. The next morning, Spirit surveyed atmospheric dust with the navigation camera and acquired additional, full-color images of Tartarus with the panoramic camera.
Sol 1388: Spirit drove 3.43 meters (11.3 feet), finally breaking free from the piles of soil built up around each of its wheels. The rover acquired post-drive images with the hazard avoidance cameras.
Sol 1389 (Nov. 29, 2007): After a morning of surveying atmospheric dust and taking additional full-color images of Tartarus, plans called for Spirit to complete a photo shoot with the navigation and hazard avoidance cameras, survey atmospheric dust with the navigation camera, and acquire thumbnail images of the sky with the panoramic camera.
Odometry:
As of sol 1388 (Nov. 28, 2007), Spirit's total odometry was 7438.82 meters (4.62 miles).
sol 1377-1383, November 26, 2007: Rover Slips in Sandy Terrain
On the way to "Winter Haven 3," the spot on the north face of "Home Plate" where NASA's Spirit rover is headed, the rover has driven into an area below a hummock (elevated area). Spirit has tried unsuccessfully during the past week to climb onto the hummock and make progress toward Winter Haven 3. Because it is critical to reach the north face while enough solar energy is available to get there, Spirit spends every available day driving. In-between drives, Spirit recharges the batteries and conducts very light remote sensing.
The rover's drive on sol 1378 (Nov. 18, 2007) ended early when Spirit's unusable, right front wheel got snagged on a buried rock, causing the rover to turn and drive into a "keep-out zone." Two Martian days later, on sol 1380 (Nov. 20, 2007), the drive faulted out again when the rover experienced more than 90-percent slip after traveling 3.6 meters (11.8 feet). The rover's handlers continue to work on strategies for enabling Spirit to drive away from the outcrop.
Spirit's top priority is to reach the north-facing slope of "Home Plate," where the rover plans to hunker down during the coming cold, winter season of waning sunlight. Spirit is healthy and all subsystems are nominal. Energy is currently around 305 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour).
Sol-by-sol summary
In addition to receiving morning instructions directly from Earth via the high-gain antenna, sending evening data to Earth at UHF frequencies via the Odyssey orbiter, and measuring atmospheric dust levels with the panoramic camera, Spirit completed the following activities:
Sol 1377 (Nov. 17, 2007): Spirit acquired an image mosaic of "West Valley" and thumbnail images of the sky with the panoramic camera.
Sol 1378: Spirit drove toward the hummock known as "Site 7," took images just before and after ending the drive with the hazard avoidance cameras, and acquired post-drive image mosaics with the navigation and panoramic cameras. The images indicated that the right front wheel had slipped off a buried rock and turned away from the targeted drive region. The rover acquired full-color foreground images, using all 13 filters of the panoramic camera.
Sol 1379: Spirit acquired a post-drive, rearward-looking mosaic of images using the navigation camera.
Sol 1380: Spirit drove 3.6 meters (11.8 feet), took images before and after the drive with the hazard avoidance cameras, and acquired post-drive image mosaics with the navigation and panoramic cameras. Early the next morning, the rover completed a survey of rock clasts and took images of the rover's tracks (to look for compositional changes revealed by trenching) and the Martian horizon with the panoramic camera.
Sol 1381: Plans called for Spirit to recharge the batteries.
Sol 1382: Plans called for Spirit to monitor dust on the miniature thermal emission spectrometer, acquire panoramic camera images of a target known as "Sorbet" near the center of Home Plate, and acquire movie frames in search of dust devils using the navigation camera.
Sol 1383 (Nov. 24, 2007): Plans called for Spirit to calibrate the panoramic camera by taking images in darkness, acquire spot images of the sky with the panoramic camera, check for drift (changes over time) in the miniature thermal emission spectrometer, and survey the sky and ground with the miniature thermal emission spectrometer.
Odometry:
As of sol 1380 (Nov. 20, 2007), Spirit's total odometry was 7,428.01 meters (4.62 miles).
sol 1370-1376, November 26, 2007: Spirit in a Race Against the Clock
With autumn only 24 Mars days away and the Sun sinking toward the northern horizon, Spirit is in a race against the clock to survive another Martian winter. As a result of dust inhibiting sunlight from reaching the solar panels, the rover must get to a suitable, north-facing location on the north rim of "Home Plate" and be safely parked for the winter by Martian day, or sol, 1412 (Dec. 23, 2007).
Spirit is already drawing more power for the drive than can be provided by the solar arrays alone. After each sol of driving, the rover spends a day recharging the batteries. That cuts potential drive time in half. In addition, the rover will not be driving on some weekend days, the Thanksgiving holidays, or days when no new instructions are being sent to the rover. Altogether, Spirit has about a dozen potential drive sols between now and the holiday season. To reach the north rim in time, Spirit must drive an average 10 meters (33 feet) per day. So far, the rover is on schedule.
Meanwhile, power is expected to decline during the next six weeks from about 325 watt-hours to about 260 watt-hours, the minimum safe power level for driving on level ground. This is due both to continued dust accumulation on the solar arrays and the lower sun angle as the Martian season moves toward winter. (One hundred watt-hours is the amount of energy needed to light a 100-watt bulb for one hour.)
Spirit's destination has been nicknamed "Winter Haven 3." Along the way, the rover will continue to measure atmospheric dust, monitor dust accumulation on the panoramic mast assembly, and measure the chemical and geologic composition of rock outcrops and sand ripples using the Mössbauer spectrometer and panoramic cameras.
Sol-by-sol summary
In addition to receiving morning instructions directly from Earth via the high-gain antenna, sending evening data to Earth at UHF frequencies via the Odyssey orbiter, and measuring atmospheric dust levels with the panoramic camera, Spirit completed the following activities:
Sol 1370 (Nov. 10, 2007): Spirit restarted the Mössbauer spectrometer and spent 23 hours collecting data on iron-bearing minerals in a rock target known as "Pecan Pie." The next morning, the rover acquired images of ripples with the panoramic camera.
Sol 1371: Spirit stowed the robotic arm and acquired full-color images, using all 13 filters of the panoramic camera, of Pecan Pie. The rover then drove 17.5 meters (57.4 feet) toward "Site 6," also known as "Site A," on Home Plate. The rover took images with the hazard avoidance camera just before and after ending the drive as well as post-drive images with the navigation and panoramic cameras.
Sol 1372: Spirit measured atmospheric dust and spent the day recharging the batteries.
Sol 1373: Spirit drove approximately 9 meters (30 feet) to Site 6, took hazard-avoidance camera images before and after finishing the drive, and acquired post-drive images with both the navigation and panoramic cameras. The following morning, Spirit acquired additional post-drive images with the navigation camera as well as panoramic cameras of an area known as "West Valley."
Sol 1374: Spirit measured atmospheric dust and spent the day recharging the batteries. The following morning, Spirit took full-color images of the rover's tracks using all 13 filters of the panoramic camera.
Sol 1375: Plans called for Spirit to drive another 15 meters (49 feet), take hazard-avoidance camera images before and after finishing the drive, and acquire post-drive images with both the navigation and panoramic cameras. The next morning, the rover was to take spot images of the sky with the panoramic camera and acquire additional post-drive images with the navigation camera. Spirit was to complete a survey of rock clasts with the panoramic camera and monitor dust on the panoramic-camera mast assembly.
Sol 1376 (Nov. 16, 2007): Plans called for Spirit to measure atmospheric dust and recharge the batteries. The following morning, Spirit was to acquire images of a hummock with the panoramic camera.
Odometry:
As of sol 1374 (Nov. 14, 2007), Spirit's total odometry was 7,415.4 meters (4.6 miles).
sol 1363-1369, November 12, 2007: Spirit Continues Drive As Power Levels Decline
Spirit has been gradually losing power, with energy levels dropping to 320 watt-hours per Martian day (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). Measurements of atmospheric dust, known as Tau, have been averaging 0.65. That dust level is typical of levels measured throughout most of the mission, but power levels are lower than in previous years because of higher dust accumulation on the solar panels. (The rover estimates dust levels by measuring opacity -- the degree to which the atmosphere is impenetrable by light. During most of Spirit's mission on Mars, except during the recent dust storms, tau values have fallen between 0 and 1.)
During the trek to reach the north edge of "Home Plate" before the next Martian winter, Spirit had time to conduct only one scientific campaign. Scientists selected a rock target nicknamed "Pecan Pie" (investigators are nicknaming targets on top of Home Plate for things served in bowls) for closer investigation, at a location known as "Site 5." Spirit brushed Pecan Pie, took pictures of it with the microscopic imager, and analyzed its composition with the alpha-particle X-ray spectrometer. Planned measurements over the weekend included an analysis of iron-bearing minerals with the Mössbauer spectrometer before resuming the drive.
The successful brush of Pecan Pie marked the first time that Spirit had used the new, two-sol brushing procedure that enabled continued use of the rock abrasion tool following the failure of the grind encoder.
Spirit continued to collect images of the west side of Home Plate (known as "West Valley" to science team members) while advancing northward. The images are important for understanding the geology as well as for planning the hoped-for, post-winter drive to a hill known as "von Braun" south of Home Plate.
Spirit remains healthy. On Sol 1369 (Nov. 9, 2007), plans called for Spirit to run a diagnostic of the rock abrasion tool by pointing it at the hazard avoidance camera for photo documentation while running the motor at various voltages. The resulting measurements of the spinning of the tool will provide a baseline for eventual failure of the motor and for comparison with Spirit's twin, Opportunity, on the other side of Mars.
Sol-by-sol summary
In addition to receiving morning instructions directly from Earth via the high-gain antenna, sending evening data to Earth at UHF frequencies via the Odyssey orbiter, measuring atmospheric dust levels with the panoramic camera, and surveying the sky and ground with the miniature thermal emission spectrometer, Spirit completed the following activities:
Sol 1363 (Nov. 3, 2007): Spirit acquired pre-drive, panoramic camera images of targets known as "Posole," "Green Chile," and "Flan," then drove 24.83 meters (84.46 feet) to Site 5 on Home Plate. The rover acquired post-drive image mosaics with the navigation and panoramic cameras. The next morning, Spirit completed a survey of rock clasts with the panoramic camera and took a mosaic of images with the navigation camera.
Sol 1364: Spirit acquired images of the distant dune field known as "El Dorado" with the panoramic camera, and after communicating with the Odyssey orbiter during its overhead pass, measured atmospheric argon with the alpha-particle X-ray spectrometer. In the morning, Spirit completed a full-color, systematic ground survey using all 13 filters of the panoramic camera.
Sol 1365: Spirit spent the day recharging the battery. The following morning, Spirit searched for dust devils using the navigation camera.
Sol 1366: Spirit placed the rock abrasion tool on Pecan Pie and acquired a mosaic of images known as the "West Valley View" with the panoramic camera. The next morning, the rover took spot images of the sky with the panoramic camera and acquired movie frames in search of dust devils with the navigation camera.
Sol 1367: Spirit acquired another mosaic of images of West Valley View with the panoramic camera. In the morning, Spirit acquired full-color images, using all 13 filters of the panoramic camera, of the rover's tracks.
Sol 1368: Spirit conducted scientific studies of Pecan Pie, including brushing the surface of the rock target with the brush on the rock abrasion tool, acquiring stereo microscopic images of the brushed surface, and collecting 9 hours of compositional data with the alpha-particle X-ray spectrometer. The rover also acquired a mosaic of images of West Valley View with the panoramic camera. The following morning, Spirit took thumbnail images of the sky with the panoramic camera.
Sol 1369 (Nov. 9, 2007): Plans called for Spirit to run diagnostic tests of the rock abrasion tool and acquire a mosaic of images of West Valley View with the panoramic camera. The rover was to spend 22 _ hours acquiring data with the Mössbauer spectrometer, be on the lookout for morning dust devils, and acquire movie frames at 8-minute intervals to record the progress of dust devils if they occurred.
Odometry:
As of sol 1367 (Oct. 30, 2007), Spirit's total odometry was 7,383.75 meters (4.59 miles).
sol 1355-1362, November 02, 2007: Spirit to Head North for the Winter
With Martian winter approaching, the science and engineering teams have been hard pressed to select a site where Spirit can spend the winter. After previously narrowing the list of candidates to two sites, Spirit's handlers decided to send the rover to the northern edge of the elevated plateau known as "Home Plate," which Spirit has been exploring for many months now.
Previously considered sites included "von Braun," "South Promontory," "Batter's Box" ("West Knoll"), and "North Home Plate." The decision means the rover will move farther away from tantalizing, new terrain to the south, but maximizes the rover's chances of surviving another winter given the excessive coating of dust on the solar arrays.
As Project Manager John Callas announced in an e-mail, "the principal discriminator was the achievable slope at each site. The north side of 'Home Plate' offers slopes of 25 degrees of northerly tilt, while 'South Promontory' offers 20 degrees of northerly tilt. That difference is about 10 watt-hours per sol, which can mean the difference between surviving and not surviving the cold, dark winter."
Meanwhile, Spirit remains healthy and all subsystems are nominal. Energy has been averaging 355 watt-hours (100 watt-hours is the amount of electricity needed to light one 100-watt bulb for one hour) and atmospheric dust measurements (Tau) have been steady at about 0.63.
Plans called for Spirit to head in a northerly direction, toward an area known as "Site 5" on top of Home Plate, starting on sol 1362 (Nov. 2, 2007). Once there, Spirit may investigate some targets with instruments on the robotic arm before continuing to the north end of Home Plate.
Meanwhile, engineers working on the rover's miniature thermal emission spectrometer have determined that degradation in performance of the spectrometer on both Spirit and its twin, Opportunity, is the result of dust deposition on the scan mirror or in the panoramic camera mast assembly. They have decided not to use the instrument on Opportunity and to use it only for high-priority targets and weekly atmospheric measurements on Spirit while they try to develop strategies for removing the dust.
In addition, tests run on sols 1355, 1358, and 1360 (Oct. 25, Oct. 29, and Oct. 31) determined that the grind motor on Spirit's rock abrasion tool failed on sol 1341 (Oct. 11, 2007) , as it did previously on Opportunity on sol 1045 (Jan. 1, 2007). However, because the rover's handlers have devised an alternate technique for grinding and brushing that takes two Martian days, they are still able to use the brushes on both rock abrasion tools.
Sol-by-sol summary
In addition to receiving morning instructions directly from Earth via the high-gain antenna, sending evening data to Earth at UHF frequencies via the Odyssey orbiter, measuring atmospheric dust levels with the panoramic camera, and surveying the sky and ground with the miniature thermal emission spectrometer, Spirit completed the following activities:
Sol 1355 (Oct. 25, 2007): Spirit unstowed the robotic arm, conducted imaging diagnostics of the rock abrasion tool, and took microscopic images of the capture magnet. The rover placed the alpha-particle X-ray spectrometer on the capture magnet, took panoramic camera images of the rover deck, and transmitted data overnight via the Odyssey orbiter. Spirit monitored dust on the panoramic camera mast assembly, surveyed the horizon with the panoramic camera, acquired a mosaic of images with the navigation camera, and acquired movie frames in search of dust devils with the navigation camera.
Sol 1356: Spirit acquired panoramic camera images of the rover deck and of rock targets nicknamed "Grays Peak," "Elk," and "San Juan." The rover acquired 6 hours worth of data with the alpha-particle X-ray spectrometer and took thumbnail images of the sky with the panoramic camera.
Sol 1357: Spirit used the navigation camera to survey the surface darkened by the rover's shadow. The rover acquired full-color images of its tracks using all 13 filters of the panoramic camera. Spirit acquired another 6 hours of data with the alpha-particle X-ray spectrometer and took spot images of the sky with the panoramic camera.
Sol 1358: Spirit took images of the filter magnet with the microscopic imager, performed diagnostic tests on the rock abrasion tool, and used the panoramic camera to take images of the rover deck and survey the horizon.
Sol 1359: Spirit turned in place for communications relays and performed a "get quick fine attitude" to check for changes in the inertial measurement unit to determine the rover's precise location. Spirit acquired post-drive images with both the navigation and panoramic cameras. In the morning, the rover completed a systematic ground survey with the panoramic camera.
Sol 1360: Spirit unstowed the robotic arm, performed diagnostic tests of the rock abrasion tool, and acquired a mosaic of microscopic images of a soil target known as "Pumpkin Pie" before placing the alpha-particle X-ray spectrometer on the target. Spirit acquired full-color images, using all 13 filters of the panoramic camera, of another soil target known as "Candy Corn." The rover collected data from Pumpkin Pie with the alpha-particle X-ray spectrometer and in the morning, scanned the sky for clouds with the navigation camera. Spirit also surveyed the horizon with the panoramic camera and acquired movie frames in search of dust devils with the navigation camera.
Sol 1361: Spirit stowed the robotic arm in preparation for the next day's drive and took full-color images, using all 13 filters of the panoramic camera, of Elk and San Juan. The rover acquired a mosaic of images with the navigation camera as part of a 360-degree panorama for drive planning. Spirit surveyed the sky at both low sun and high sun with the panoramic camera.
Sol 1362 (Nov. 2, 2007): Plans called for Spirit to drive toward Site 5, acquire full-color, mid-drive images of Pumpkin Pie with all 13 filters of the panoramic camera, and acquire post-drive images with both the navigation and panoramic cameras. The following morning, Spirit was to complete a survey of rock clasts with the panoramic camera and scan the sky for clouds with the navigation camera.
Odometry:
As of sol 1359 (Oct. 30, 2007), Spirit's total odometry was 7,339.70 meters (4.56 miles).
sol 1348-1354, October 30, 2007: Spirit Considers Options for Surviving Another Winter on Mars
Spirit's handlers are currently confronted with the decision of where to send the rover for the winter. Dust deposition on the rover's solar panels, a product of the recent dust storms, has made power predictions for the upcoming winter even worse than those experienced during Spirit's last Martian winter. Members of the science team hope to find a place where Spirit can achieve a tilt of 20 degrees or more toward the north, facing the sun.
During the week, Spirit drove approximately 50 meters (164 feet) in a southerly and southeasterly direction toward a potential off-ramp from the top of the elevated plateau known as "Home Plate."
Proposed locations for a winter haven include driving south down the off-ramp and making a break for "von Braun," a hill approximately 120 meters (390 feet) away; heading north across Home Plate and driving down the north-facing edge; or driving west of Home Plate to a hill tentatively identified as "West Knob."
On sols 1349 and 1351 (Oct. 19 and Oct. 21, 2007), Spirit acquired long-baseline stereo images of von Braun, to the south of Home Plate.
Spirit has been generating approximately 345 watt-hours of solar array energy (enough to run a 100-watt bulb for almost 3 1/2 hours) per Martian day (or sol). Measurements of atmospheric dust opacity, known as Tau, have been approximately 0.7 (higher Tau measurements correspond to more dust).
Sol-by-sol summary
In addition to receiving morning instructions directly from Earth via the high-gain antenna, sending evening data to Earth at UHF frequencies via the Odyssey orbiter, measuring atmospheric dust levels with the panoramic camera, and surveying the sky and ground with the miniature thermal emission spectrometer, Spirit completed the following activities:
Sol 1348 (Oct. 18, 2007): Spirit drove approximately 14 meters (46 feet) to get into position for the first "eye," or vantage point, of the long-baseline stereo panorama. The rover took a 7-by-1, post-drive image mosaic, measured the thermal characteristics of the external calibration target with the miniature thermal emission spectrometer, and acquired thumbnail images of the sky with the panoramic camera.
Sol 1349: Spirit created a list of files on board and then proceeded to acquire the left-eye portion of the long-baseline stereo panorama. The rover relayed data to Earth during the overnight pass of the Odyssey orbiter, completed a systematic ground survey using all 13 filters of the panoramic camera, and took spot images of the sky with the panoramic camera.
Sol 1350: Spirit drove approximately 8 meters (26 feet) to the second vantage point for the long-baseline stereo view and then acquired a post-drive image mosaic (a 6-by-1 panel) with the navigation camera. The rover acquired images of the external magnets through all filters of the panoramic camera.
Sol 1351: Spirit acquired the right-eye portion of the long-baseline stereo panorama and spent 6 1/2 hours collecting measurements of atmospheric argon with the alpha-particle X-ray spectrometer. The rover surveyed the horizon with the panoramic camera and watched for dust devils.
Sol 1352: Spirit acquired pre-drive images with the panoramic camera to fill in portions of the right-eye view of the stereo image mosaic. The rover drove approximately 6 meters (20 feet) south-southeast toward the potential south off-ramp of Home Plate and acquired a 5-by-1 mosaic of images with the navigation camera as well as a 4-by-1 mosaic of images with the panoramic camera. Spirit took spot images of the sky, conducted a survey of rock clasts with the panoramic camera, and searched for dust devils with the navigation camera.
Sol 1353: Spirit drove approximately 10 meters (33 feet) south-southeast toward the potential south off-ramp and acquired a 5-by-1, post-drive image mosaic with the navigation camera and a 4-by-1, post-drive image mosaic with the panoramic camera. The rover surveyed the horizon and completed a survey of rock clasts with the panoramic camera. Spirit watched for dust devils.
Sol 1354 (Oct. 24, 2007): Spirit acquired a 4-by-1, pre-drive panel of images of "West Knob" with the panoramic camera and drove approximately 12 meters (39 feet) south-southeast toward the potential off-ramp. The rover acquired a 5-by-1, post-drive image mosaic with the navigation camera and a 4-by-1 image mosaic with the panoramic camera. Spirit tested communications with the Mars Express orbiter, a European Space Agency mission, in preparation for next year's arrival of NASA's Phoenix lander. The rover completed a systematic ground survey and horizon survey with the panoramic camera.
Odometry:
As of sol 1354 (Oct. 24, 2007), Spirit's total odometry was 7,338.78 meters (4.56 miles).
sol 1343-1347, October 29, 2007: Spirit Continues Studies of Rocks on "Home Plate"
Spirit is healthy and continues to investigate "Home Plate." After completing extensive studies of "Site 3" using the Mössbauer spectrometer and other instruments, the rover proceeded toward "Site 4."
Meanwhile, it's already time for Spirit to start thinking about winter again. Over the coming weekend, the rover was scheduled to acquire long-baseline stereo images of Home Plate and surrounding areas in search of a safe winter haven.
The grinding encoder on Spirit's rock abrasion tool appears to have suffered the same fate as that of Spirit's twin, Opportunity, on the other side of Mars. An investigation is under way, but all indications are that activities using the rock abrasion tool will now require two Martian days, or sols.
On sol 1346 (Oct. 16, 2007), Spirit drove approximately 10 meters (33 feet) toward Site 4 and added another 12 meters (39 feet) of driving on sol 1347 (Oct. 17, 2007).
Sol-by-sol summary
In addition to receiving morning instructions directly from Earth via the high-gain antenna, returning data in the evening at UHF frequencies via the Odyssey orbiter, measuring atmospheric dust levels (known as tau measurements) with the panoramic camera, and surveying the sky and ground with the miniature thermal emission spectrometer, Spirit completed the following activities:
Sol 1343 (Oct. 13, 2007): Spirit restarted the Mössbauer spectrometer and collected data for 22 hours with the instrument from a target called "Humboldt Peak." The rover acquired remote data from a rock target known as "Mt. Eolus" with the miniature thermal emission spectrometer and a 6-by-1 image mosaic with the panoramic camera.
Sol 1344: Spirit restarted the Mössbauer spectrometer and resumed data collection from Humboldt Peak for 23 hours. The rover acquired spot images of the sky and a 4-by-1 image mosaic with the panoramic camera and collected remote data from a rock known as "Pikes Peak" using the miniature thermal emission spectrometer.
Sol 1345: Spirit resumed collecting Mössbauer data from Humboldt Peak for another 23 hours. The rover acquired remote data from a target dubbed "Mt. Sneffels" with the miniature thermal emission spectrometer and spot images of the sky with the panoramic camera. Spirit monitored dust on the rover mast assembly.
Sol 1346: Spirit ran tests on the rock abrasion tool and stowed the robotic arm before taking pre-drive images with the panoramic camera and driving about 10 meters (33 feet) toward Site 4 on Home Plate. The rover acquired a 5-by-1, post-drive image mosaic with the navigation camera as well as a 4-by-1 mosaic with the panoramic camera. The rover took spot images of the sky and foreground images with the panoramic camera.
Sol 1347 (Oct. 17, 2007): Spirit conducted a pre-drive survey of the rover's surroundings with the panoramic camera and drove another 12 meters (39 feet) toward Home Plate Site 4. The rover acquired a 7-by-1, post-drive image mosaic with the navigation camera. Spirit also took images of dust in the sky, conducted a survey of rock clasts, and acquired images of a rock target called "Conundrum Peak" using the panoramic camera.
Odometry:
As of sol 1347 (Oct. 17, 2007), Spirit's total odometry was 7,286 meters (4.5 miles).
sol 1337-1342, October 11, 2007: Hardy Rover Continues to Celebrate Milestones
After enduring seasonal dust storms much stronger than the rover was designed to survive, Spirit has now been exploring the Red Planet for two Martian years. That is a period of time longer than three years on Earth and more than 10 times the duration of the original 90-day mission. In fact, on Oct. 1, 2007, the rover entered the fifth extension of its original mission!
Spirit has arrived at a field of boulders that the science team is nicknaming after Colorado 14'ers -- Earth peaks taller than 14,000 feet. Atmospheric dust levels continue to wane, and Spirit took advantage of additional sunlight by using solar power to transmit data to Earth at night when the Odyssey orbiter passed overhead. These transmissions will free up more of Spirit's on-board computer memory.
Spirit began studies of a rock known as "Humboldt Peak" at "Site 3a." This particular rock is dark and angular and appears to be similar to "Comanche"-class rocks encountered by the rover earlier in the mission on "Husband Hill."
On sol 1339 (Oct. 9, 2007), the rover conducted a communications test with the European Space Agency's Mars Express orbiter. Mars Express will provide backup communications during the entry, descent, and landing of the Phoenix mission, due to arrive near the north pole of Mars on the United States' Memorial Day weekend of 2008.
The relays with Mars Express are a prime example of the value of having multiple spacecraft at Mars -- by using the same UHF radio frequencies as those used by the rovers and Mars Express, Phoenix will benefit from tried-and-true communications links already in place. Another example is Spirit's ability to take thermal measurements looking up into the atmosphere that fill in data that cannot be collected from above by orbiters looking down. The result is a more complete profile of the Martian atmosphere.
Sol-by-sol summary
In addition to measuring atmospheric dust levels (known as tau measurements) with the panoramic camera and surveying the sky and ground with the miniature thermal emission spectrometer, Spirit completed the following activities:
Sol 1337 (Oct. 7, 2007): Spirit acquired full-color images, using all 13 filters of the panoramic camera, of boulders at Site 3a. The rover approached Humboldt Peak and acquired post-drive images with the hazard avoidance and navigation cameras.
Sol 1338: Spirit completed a survey of rock clasts and acquired thumbnail images of the sky with the panoramic camera. The rover calibrated the miniature thermal emission spectrometer and acquired data from "Mt. Elbert" with the miniature thermal emission spectrometer. The rover transmitted data to Earth overnight via the Odyssey orbiter.
Sol 1339: Spirit calibrated the miniature thermal emission spectrometer and performed late-night tests of communications with the Mars Express orbiter.
Sol 1340: Spirit searched for morning dust devils with the navigation camera and checked for drift (changes with time) in the miniature themal emission spectrometer. Spirit acquired a stereo mosaic of microscopic images of Humboldt Peak and placed the alpha-particle X-ray spectrometer on the target for overnight studies prior to brushing the surface. The rover surveyed a target known as "Crestone Needle" with the miniature thermal emission spectrometer and then conducted an 18-hour, overnight study of Humboldt Peak with the alpha-particle X-ray spectrometer, while also relaying data to Earth via the Odyssey orbiter.
Sol 1341: Spirit took spot images of the sky with the panoramic camera, checked for drift in the miniature thermal emission spectrometer, and brushed the surface of Humboldt Peak with the rock abrasion tool. The rover placed the alpha-particle X-ray spectrometer on the newly brushed surface. Spirit surveyed targets dubbed "Snowmass" and "Castle Peak" with the miniature thermal emission spectrometer. The rover conducted a 19-hour, overnight study of the brushed surface of Humboldt Peak with the alpha-particle X-ray spectrometer.
Sol 1342 (Oct. 12, 2007): Plans called for Spirit to look for morning clouds with the navigation camera and check for drift in the miniature thermal emission spectrometer. The rover was to switch tools to the Mössbauer spectrometer and spend 23 hours collecting data from the brushed surface of Humboldt Peak with the instrument. Spirit was also scheduled to relay data to Earth during the overnight pass of the Odyssey orbiter and acquire data from a target known as "Mt. Evans" using the miniature thermal emission spectrometer. The next morning, the rover was expected to survey the sky with the panoramic camera.
Odometry:
As of sol 1337 (Oct. 7, 2007), Spirit's total odometry was 7,261.29 meters (4.5 miles).
sol 1329-1336, October 08, 2007: Rover Experiences Data Backlog
Spirit is in good health and on the move toward an appealing field of boulders at the southwest corner of "Home Plate." Preliminary data from the miniature thermal emission spectrometer indicates these boulders may be compositionally related to "Comanche"-class rocks first encountered on "Husband Hill."
Flash memory limited the rover's activities as the volume of memory in use edged up to more than 70 percent of capacity. After completing work on a 360-degree panorama from "site 3," Spirit had more than 711 megabits of unsent data in flash memory, 453 of which were data from the panoramic camera. Spirit now has enough power to transmit data to Earth during overnight Odyssey passes and took advantage of two of those opportunities this week.
Sol-by-sol summary
In addition to starting and ending each day by measuring atmospheric dust levels (known as a tau measurement) and surveying the sky and ground with the miniature thermal emission spectrometer, Spirit completed the following activities:
Sol 1329 (Sept. 29, 2007): Spirit restarted the Mössbauer spectrometer and collected data for 22 hours from a target known as "Texas Chili." The rover acquired a 3-by-2-frame mosaic of images of site 3 with the panoramic camera.
Sol 1330: Spirit acquired a microscopic image mosaic of Texas Chili and a bore sight of the microscopic imager with the panoramic camera to check the accuracy of its alignment. The rover then stowed the robotic arm, surveyed the external calibration target, and acquired a 5-point survey of the sky and ground with the miniature thermal emission spectrometer. During the afternoon overpass of the Odyssey orbiter, Spirit acquired data from a target known as "Harmony Point2" with the miniature thermal emission spectrometer.
Sol 1331: Spirit acquired a 5-by-1 image mosaic of site 3 with the panoramic camera and completed acquisition of the 360-degree panorama of the rover's surroundings as viewed from site 3. Spirit also acquired a 6-by-1 mosaic of images with the navigation camera and took thumbnail images of the sky with the panoramic camera. During the afternoon Odyssey overpass, the rover surveyed a target known as "Ohridiski2" with the miniature thermal emission spectrometer.
Sol 1332: Spirit acquired a 5-by-1 image mosaic of site 3 and a 4-by-1, pre-drive image mosaic with the panoramic camera. The rover bumped backward 50 centimeters (20 inches) and acquired full-color images of the work volume studied by instruments on the robotic arm using all 13 filters of the panoramic camera. Spirit drove 10.1 meters (33.1 feet) toward a target area known as "site 3a," pausing to take mid-drive images with the navigation camera. The rover acquired a 5-by-1, post-drive image mosaic with the navigation camera and a 4-by-1 image mosaic with the panoramic camera.
Sol 1333: Martian winds cleared away some dust from the solar panels, resulting in a 1-percent increase in solar power, or about 10 watt-hours. Total solar output for the day was 361 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt light bulb for 1 hour). Spirit surveyed the horizon with the panoramic camera and completed a full-color, systematic ground survey using all 13 filters of the panoramic camera.
Sol 1334: Spirit completed a survey of rock clasts using the panoramic camera and then continued to drive toward site 3a. After the drive, the rover acquired images with the hazard avoidance cameras and a 4-by-1 image mosaic with the navigation camera. Spirit transmitted data to Odyssey during the overnight pass of the orbiter.
Sol 1335: Spirit completed a 5-point survey and then a 7-point survey of the sky and ground using the miniature thermal emission spectrometer.
Sol 1336 (Oct. 6, 2007): Spirit monitored dust on the panoramic camera mast assembly and acquired images with the navigation camera in support of observations with the miniature thermal emission spectrometer. The rover then completed a 7-point survey of the sky and ground as well as a systematic foreground survey with the miniature thermal emission spectrometer. Spirit transmitted data to the Odyssey orbiter during its overnight pass. The rover was slated to conduct a 5-point survey of the sky and ground the next morning with the miniature thermal emission spectrometer.
Odometry:
As of sol 1333 (Oct. 3, 2007), Spirit's total odometry was 7,244.32 meters (4.5 miles).
sol 1321-1328, September 27, 2007: Spirit Arrives at "Stratigraphic Wonderland"
Spirit completed the rover's longest 5-wheel drive to date en route to a platy rock surface nicknamed "Texas Chili" in an area scientists are calling a "stratigraphic wonderland." The platy outcrop is at site 3 on top of "Home Plate" and is the focus of in-depth scientific investigation.
Two sols after not receiving a scheduled data transmission, Spirit drove 19.21 meters (63.02 feet) to the rover's current location about 15 meters (49 feet) away from a field of boulders.
Meanwhile, atmospheric dust levels continued to decline. Tau measurements of atmospheric opacity dropped to 1.06 on sol 1327 (Sept. 27, 2007), with a dust factor of 0.48. Spirit has been averaging 350 watt-hours per Martian day (100 watt-hours is the amount of electricity needed to light a 100-watt bulb for one hour).
Scientific studies of the platy outcrop included alpha-particle X-ray spectrometer measurements both before and after brushing the surface, analysis with the Mössbauer spectrometer, and acquisition of microscopic images as well as a 360-degree panorama.
Sol-by-sol summary
Spirit began each Martian day by measuring atmospheric dust with the panoramic camera, checking for drift (changes with time) in the miniature thermal emission spectrometer, and surveying the sky and ground with the miniature thermal emission spectrometer. In addition to those tasks, Spirit completed the following activities:
Sol 1321 (Sept. 21, 2007): Rather than completing the drive toward Home Plate as intended, Spirit executed the previous sol's activities. As a result of an internal failure in a station at the Deep Space Network in Madrid, rover handlers were unable to transmit instructions to Spirit via the rover's high-gain antenna.
Sol 1322: Spirit spent the first sol of a three-sol weekend collecting remote science data, including panoramic camera images of a target known as "Ambrosia" and miniature thermal emission spectrometer measurements of Ambrosia as well as targets known as "Bisque" and "Cobbler."
Sol 1323: Spirit acquired panoramic camera images of Bisque and Cobbler before completing the 19.21-meter (63.02-foot) drive to site 3 on Home Plate. The rover took images with the hazard avoidance cameras before and after ending the drive and acquired post-drive image mosaics with the navigation and panoramic cameras.
Sol 1324: Spirit acquired near-field panoramic camera images and spent the third sol of a three-sol weekend collecting untargeted remote sensing data. Observations included movie frames in search of dust devils with the navigation camera and a systematic foreground survey with the miniature thermal emission spectrometer.
Sol 1325: Spirit surveyed rock clasts with the panoramic camera and scanned the sky for clouds with the navigation camera. The rover began work on a 360-degree panorama as well as scientific studies of Texas Chili. Spirit acquired navigation camera images in support of observations with the miniature thermal emission spectrometer, completed a full-color, systematic, foreground survey using all 13 filters of the panoramic camera, and acquired a mosaic of images of site 3 with the panoramic camera. Spirit studied targets known as "Hardy Point," "Harmony Point," and "Ohridiski" with the miniature thermal emission spectrometer. The rover unstowed the robotic arm and placed the alpha-particle X-ray spectrometer on Texas Chili.
Sol 1326: In the morning, Spirit monitored dust on the rover mast. Later, the rover acquired more panoramic camera images of site 3, brushed the surface of Texas Chili with the rock abrasion tool, and acquired images of the microscopic imager with the front hazard avoidance camera to monitor dust accumulation. Spirit placed the alpha-particle X-ray spectrometer back on the target and collected data for about 18 hours.
Sol 1327: In the morning, Spirit received communications via the European Space Agency's Mars Express orbiter. The rover acquired more panoramic camera images of site 3, switched tools from the alpha-particle X-ray spectrometer to the Mössbauer spectrometer, and collected Mössbauer data from Texas Chili for about 21 hours.
Sol 1328 (Sept. 28, 2007): Spirit took thumbnail images of the sky with the panoramic camera, re-started the Mössbauer spectrometer, and collected Mössbauer data from Texas Chili for about 25 hours. The rover took more panoramic camera images of site 3 and was slated to continue doing so the following morning.
Odometry:
As of sol 1327 (Sept. 27, 2007), Spirit's total odometry was 7,234.09 meters (4.49 miles).
sol 1315-1320, September 25, 2007: Spirit Makes Progress Across "Home Plate"
Spirit is healthy after finishing a remote sensing campaign at Site 2 on "Home Plate." The work included collecting long-baseline stereo images of "Husband Hill," studying a possible fracture in the bedrock, and conducting reconnaissance looking west, southwest, and south in search of drive paths and geological information.
On Sol 1315 (Sept. 14, 2007), Spirit began driving toward Site 3, about 30 to 40 meters (100 to 130 feet) away from Site 2 at the southern end of Home Plate. Scientists wanted to gain elevation for a better view of the southern part of Home Plate and "Low Ridge." They planned to use instruments at the end of the rover's robotic arm to document alteration trends from northwest to southeast across Home Plate and get a better look at vesicular basalts and potential "Comanche"-class rocks (so named for rocks examined earlier in the mission while Spirit was crossing Husband Hill).
Later the same day, after the rover completed the drive, the Odyssey orbiter went into safe mode, and Spirit stayed put to perform remote sensing. On sols 1318 and 1319 (Sept. 17-18, 2007), Spirit communicated directly with Earth via the high-gain antenna, enabling the operations team to confirm that the rover was still healthy and had successfully completed the sol 1315 drive. On Wednesday, September 19th, Odyssey resumed relaying data from Spirit via UHF radio transmissions, clearing the way for Spirit to continue driving to Site 3.
Sol-by-sol summary
In addition to measuring atmospheric opacity with the panoramic camera, surveying the sky and ground with the miniature thermal emission spectrometer, and checking for drift (changes with time) in the miniature thermal emission spectrometer, Spirit completed the following activities:
Sol 1315 (Sept. 14, 2007): Spirit surveyed a soil target known as "Broth" and rock targets known as "Vichyssoise" and "Cioppino" with the miniature thermal emission spectrometer. The rover drove toward Home Plate Site 3, acquiring images along the way with the hazard avoidance cameras. After the drive, Spirit took images of the surroundings with the navigation and panoramic cameras.
Sol 1316: Spirit acquired 8 minutes worth of movie frames in search of dust devils using the navigation camera. Spirit acquired a panel of navigation camera images looking to the rear and a mosaic of panoramic camera images of the fracture. The rover surveyed the external calibration target with the miniature thermal emission spectrometer.
Sol 1317: Spirit monitored dust accumulation on the rover mast with the panoramic camera and acquired full-color images of the foreground using all 13 filters of the panoramic camera. The rover completed a survey of rock clasts with the panoramic camera. Spirit scanned the foreground using both the navigation camera and miniature thermal emission spectrometer. Spirit recalibrated the panoramic camera's measurements of atmospheric opacity.
Sol 1318: Spirit took thumbnail images of the sky with the panoramic camera and checked the external calibration target with the miniature thermal emission spectrometer. The rover spent most of the sol taking measurements of atmospheric dust.
Sol 1319: Spirit continued to check the external calibration target with the miniature thermal emission spectrometer and acquired movie frames in search of dust devils with the navigation camera.
Sol 1320 (Sept. 20, 2007): Spirit took thumbnail images of the sky with the panoramic camera and monitored dust accumulation on the mast with the miniature thermal emission spectrometer.
Odometry:
As of sol 1315 (Sept. 14, 2007), Spirit's total odometry was 7,214 meters (4.48 miles).
sol 1309-1314, September 18, 2007: Spirit Explores Top of "Home Plate"
After spending some time getting used to the terrain on top of "Home Plate," Spirit began driving across the top of the elevated plateau, en route to taking more images and examining a possible fracture in the bedrock.
On the rover's 1,310th Martian day, or sol, of exploration (Sept. 9, 2007), Spirit completed a drive characterization to determine how the rover responded on Home Plate terrain. After passing that test, Spirit proceeded toward a destination known as "Site 2." Plans called for the rover to acquire the second portion of a long-baseline, stereo view of "Husband Hill" and study the potential fracture. In addition, Spirit was slated to collect remote sensing data looking to the west, southwest, and south in search of possible drive paths as well as geological information.
Sol-by-sol summary
In addition to measuring atmospheric opacity with the panoramic camera, surveying the sky and ground with the miniature thermal emission spectrometer, and checking for drift (changes with time) in the miniature thermal emission spectrometer, Spirit completed the following activities:
Sol 1309 (Sept. 8, 2007): Spirit examined targets known as "Gumbo," "Goulash," "Stew," and "Pudding" with the miniature thermal emission spectrometer. Spirit took wide-range atmospheric dust measurements using the panoramic camera and then, after the evening pass of the Odyssey orbiter, recalibrated the dust measurements of the panoramic camera.
Sol 1310: Spirit acquired panoramic camera images of Gumbo and Goulash. The rover turned in place to characterize the drive toward Site 2 and started driving in that direction. Spirit took images with the hazard avoidance cameras just before and after completing the drive as well as post-drive images with the panoramic camera.
Sol 1311: Spirit surveyed the horizon with the panoramic camera.
Sol 1312: Spirit monitored dust accumulation on the rover's mast with the panoramic camera and continued driving. The rover acquired images with the hazard avoidance cameras before and after completing the drive and acquired post-drive images with the panoramic and navigation cameras. Spirit acquired a rearward-looking mosaic of navigation camera images, surveyed the external calibration target with the miniature thermal emission spectrometer, and completed a systematic ground survey using all 13 filters of the panoramic camera.
Sol 1313: Spirit surveyed the horizon with the panoramic camera.
Sol 1314 (Sept. 13, 2007): Spirit acquired full-color views, using all 13 filters of the panoramic camera, of the fracture on Home Plate. The rover acquired forward-looking images with the panoramic camera and acquired data from targets dubbed "Tapioca," "Bouillabaisse," and "Dumplings" with the miniature thermal emission spectrometer. Spirit acquired wide-range measurements of atmospheric dust with the panoramic camera and measured atmospheric argon with the alpha-particle X-ray spectrometer. After the overpass of the Odyssey orbiter, Spirit recalibrated dust measurements with the panoramic camera. The following morning, the rover was to acquire panoramic camera images of Dumplings and complete a survey of rock clasts.
Odometry:
As of sol 1312 (Sept. 11, 2007), Spirit's total odometry was 7,206 meters (4.48 miles).
sol 1303-1308, September 10, 2007: Spirit Finally Arrives at Home Plate!
After remaining beyond the margins of Home Plate ever since exiting its northeast edge on Sol 774 (March 7, 2006) to survive the first winter on Mars, Spirit finally climbed on top of the elevated, circular plateau that scientists believe is volcanic in origin.
Before completing the final drive, however, Spirit returned to the soil patch nicknamed "Gertude Weise," made of nearly pure silicon dioxide, to acquire data that will help scientists characterize how much dust has accumulated on the instrument optics of the miniature thermal emission spectrometer.
The miniature thermal emission spectrometer is inside the boxy body of the rover, below the mast. Mirrors inside the mast allow the instrument to see outside. The rover has been using the spectrometer to measure changes in the atmosphere during the recent dust storm on Mars. When the instrument is not in use, a cover protects it from dust floating in the atmosphere but it isn't air-tight.
After completing measurements of Gertrude Weise, Spirit was once again on the move. The rover attempted to "thread the needle" by driving between two rocks on sol 1304 (Sept. 3, 2007) and place the rear two wheels on the top of Home Plate (Spirit must drive backward to drag the frozen right front wheel).
As it turned out, the drive was more difficult than anticipated. On the first attempt, Spirit immediately stopped driving when the rover's wheels entered an area designated as a keepout zone. This occurred as the rover was attempting to compensate for drag from the right front wheel by turning slightly in the opposite direction. Normally, the dragging wheel causes Spirit to yaw counter-clockwise (as viewed from above), but the amount of counter-clockwise spin depends on the amount of drag encountered by the right front wheel. Rocky surfaces cause less drag than soil. In this case, the drag was less than anticipated.
On sol 1306 (Sept. 5, 2007), Spirit tried again and executed the drive flawlessly! Now that the rover's two rear wheels are on top of the eastern edge of Home Plate, Spirit is in position to explore the top of the elevated plateau along its eastern and southern edges. The next planned stop is a few meters away in an area known as "Site 2," located midway along the eastern scarp of Home Plate east scarp and several meters to the west of the scarp. (If you compared the roughly circular shape of the top of Home Plate to a clock, Site 2 would be at 3:30.)
After that, scientists plan to have Spirit proceed to "Site 3," at the southern end of Home Plate (6 o'clock position) and "Site 4," at the southwestern corner of Home Plate (7:30 position).
By collecting data at all these sites, scientists hope to interpret the geologic structure of Home Plate, determine how the rock chemistry changes from one side to the other, and elucidate a fracture that crosses the plateau from west to east. Along the way, the rover will take images of the south face of "Husband Hill" to the north and outcrops known as "Goddard" and "von Braun" to the south.
In recent months, rover handlers have been naming local features and targets around Home Plate for deceased members of the All-American Girls Professional Baseball League. Because Home Plate is bowl-shaped, scientists have decided to name features on top of Home Plate after things served in bowls. Stay tuned for upcoming yummy descriptions!
Sol-by-sol summary:
In addition to measuring atmospheric opacity with the panoramic and navigation cameras, surveying the sky and ground with the miniature thermal emission spectrometer, and checking for drift (changes with time) in the miniature thermal emission spectrometer, Spirit completed the following activities:
Sol 1303 (Sept. 2, 2007): Spirit studied a target known as "Gertrude Weise14," the background of the target, a soil target labeled "Innocent Bystander Disturbed Area 1," and a target known as "Mary Dailey3" as well as its background with the miniature thermal emission spectrometer. Spirit recalibrated the panoramic camera and acquired miniature thermal emission spectrometer data on a target dubbed "Joanne Winter2."
Sol 1304: Spirit acquired full-color images of the disturbed soil area using all 13 filters of the panoramic camera before driving 2.42 meters (7.94 feet) toward Home Plate. The rover took images just before and after completing the drive with the hazard avoidance cameras as well as post-drive images with the navigation and panoramic cameras.
Sol 1305: Spirit surveyed the rover's external calibration target using the miniature thermal emission spectrometer and acquired movie frames in search of dust devils using the navigation camera. The rover recalibrated the panoramic camera.
Sol 1306: Before beginning the sol's drive, Spirit acquired full-color images of the rover's external calibration target as well as the disturbed soil area of Innocent Bystander using all 13 filters of the panoramic camera. After completing the 8.21-meter (26.9-foot) drive, the rover took images of the surrounding terrain with the navigation camera and forward-looking images with the panoramic camera.
Sol 1307: Spirit completed a survey of rock clasts with the panoramic camera and assessed the calibration target with the miniature thermal emission spectrometer.
Sol 1308 (Sept. 7, 2007): Spirit acquired images of dust in the sky with the panoramic camera, calibrated the miniature thermal emission spectrometer, and listed files in the rover's flash memory (a type of rewritable electronic memory that retains information even when power is off). Spirit completed a systematic foreground survey using all 13 filters of the panoramic camera and measured albedo (surface reflectivity) using the panoramic camera. With the miniature thermal emission spectrometer, the rover surveyed a soil target known as "Beef_Chili," a rock target known as "Cajun_Chili," and the external calibration target.
Odometry:
As of sol 1306 (Sept. 5, 2007), Spirit's total odometry was 7,182.49 meters (4.46 miles).
sol 1295-1302, August 30, 2007: Spirit Slowly Emerges from Blanket of Dust
Spirit remains healthy as the rover slowly picks up more solar energy. The dust storms appear to be over, at least for now, and the skies are slowly clearing. Unfortunately, what energy Spirit has gained from cleaner skies has been offset by losses to dustier solar arrays. Still, Spirit has the energy, about 325 watt-hours, to finally be roving again.
Tau, a measure of atmospheric dustiness, declined slightly. As of Sol 1299 (Aug. 29, 2007), the Sun was at about 8 percent of its full brightness, an increase of a little more than 2 percent compared with five sols earlier. Dust on the rover's solar arrays increased by about 3 percent and only about 59 percent of the sunlight hitting the arrays gets through to make electricity.
But rather than getting a 1-percent boost in solar power, the rover has been just about breaking even. The reason is that Tau measures direct sunlight but there's also scattered sunlight and it, too, increased by about 1 percent.
Much of the dust previously seen on the turret has blown or fallen off. Dust contamination remains a concern, particularly for the microscopic imager, where some of the dust clumps visible in earlier images have fallen out or moved out of the line of sight.
On Sol 1296 (Aug. 25, 2007), Spirit resumed driving to "Home Plate" and more specifically, to a location with gentle slopes and few rocks known as "the on-ramp." This drive was a turn-in-place, given Spirit's frozen right front wheel, to get the rover pointed in the right direction.
After two sols of remote sensing with emphasis on characterizing whatever dust had accumulated on the panoramic camera, Spirit's handlers decided to have the rover retrace its tracks to assess what dust contamination might be present on the miniature thermal emission spectrometer. To do this, they needed to measure a known target.
With a blanket of dust everywhere, scientists needed a way to distinguish dust on targets of scientific interest from dust on the optics. The best target for that was "Gertrude Weise," a patch of nearly pure-silica soil uncovered by Spirit's wheels. Rover planners decided to have the rover drag its wheels through it again to scrape off newly acquired dust and expose the same pure silica as before. Differences between old and new measurements would be due to dust on the instrument itself; once that signature was known, it could be subtracted from future measurements.
The first drive to Gertrude Weise was a little short and didn't uncover the silica as hoped. Spirit's handlers planned a second drive on Sol 1300 (Aug. 30, 2007), during which the rover was to scuff the soil with a half-turn of the left front wheel, then scuff it more by locking both left and right front wheels and driving them backward across Gertrude Weise. They then planned to have the rover back up some more to take images and move toward the Home Plate on-ramp.
Spirit was expected to resume the long-awaited trek to Home Plate on sol 1303 (Sept. 2, 2007).
Sol-by-sol summary:
In addition to daily direct-from-Earth uplinks over the rover's high-gain antenna, relays to Earth at UHF frequences via the Odyssey orbiter, surveys of the sky and ground with the miniature thermal emission spectrometer, measurements of atmospheric opacity with the panoramic and navigation cameras, and image acquisition with the front and rear hazard avoidance cameras, Spirit completed the following activities:
Sol 1295 (Aug. 25, 2007): Spirit conducted remote sensing and acquired panoramic camera images of targets known as "Eileen Dean," "Dorothy Mueller," and "Stealing Third."
Sol 1296: Spirit drove and turned in place 156 degrees to point toward the on-ramp of Home Plate. The rover assessed dust accumulation on the lenses of the panoramic camera and measured atmospheric opacity (Tau) at different times of day.
Sol 1297: Spirit conducted remote sensing and general atmospheric science, including characterizing dust on the panoramic camera.
Sol 1298: Spirit drove, returning to Gertrude Weise.
Sol 1299: Spirit conducted remote sensing and general atmospheric science, including characterizing dust on the panoramic camera.
Sol 1300: Plans called for Spirit to drive, scuff and drag its wheels over Gertrude Weise, and acquire images of the target. The rover was to conduct atmospheric science.
Sol 1301: Plans called for Spirit to conduct remote sensing and general atmospheric science, including characterizing dust on the panoramic camera. The rover was to measure atmospheric argon with the alpha-particle X-ray spectrometer.
Sol 1302 (Sept. 1, 2007): Plans called for Spirit to conduct remote sensing and general atmospheric science, including characterizing dust on the panoramic camera.
Odometry:
As of sol 1298 (Aug. 28, 2007), Spirit's total odometry was 7,169 meters (4.45 miles).
sol 1288-1294, August 23, 2007: Spirit Tries to Coax Dust from Microscopic Imager
For the first time since arriving on Mars in 2004, Spirit attempted to remove dust from the microscopic imager in a "blobs away" campaign to help the rover recover from a series of dust storms. The rover remained healthy as the Gusev Crater region continued to emerge from the recent storms. Gloominess caused by suspended dust in the atmosphere remained high but continued its downward trend. Dust falling out of the atmosphere continued to accumulate on the solar panels, limiting power gains from decreasing atmospheric opacity, known as Tau.
Between the rover's 1,288th and 1,291st Martian days, or sols, of exploration (Aug. 18 and Aug. 21, 2007), Tau values went down from 3.2 to 3.0. During the same time, the accumulation of dust on the solar arrays rose from 0.664 to 0.640 (a dust factor of 1.0 corresponds to a perfectly clean array). Solar energy on sol 1291 (Aug. 21, 2007) was 313 watt-hours (100 watt-hours is what it takes to light a 100-watt bulb for 1 hour).
The "blobs away" campaign, designed to dump dust from the surface of the microscopic imager lens, involved repeatedly taking images, opening and closing the dust cover, pointing the instrument slightly upward at an angle of 20 degrees (with the hinge down to avoid dumping caked dust on the lens), and taking more images and opening and closing the dust cover. Improved image quality after the procedure indicated that either some dust fell out or simply moved around. Dust decontamination efforts continue.
Spirit acquired microscopic images of mobile surface ripples and a soil target nicknamed "Norma Luker" on Sol 1291 (Aug. 21 2007). Despite dust motes on the lens, the images were useful to the science team.
Engineers were investigating the cause of a failed transmission on sol 1292 (Aug. 22, 2007), in which planned activities did not get on board the spacecraft. Potential causes being investigated included an uplink glitch or interference from a simultaneous uplink to the Mars Reconnaissance Orbiter.
Spirit "drove" 42 centimeters (16 ½ inches) to a new position. Weekend plans called for the first multi-meter drive toward the elevated plateau known as "Home Plate" as well as test transmissions to the European Mars Express orbiter in support of next year's arrival of the Phoenix spacecraft now en route to Mars.
Martian weather reports as of Aug. 22 indicated a lull in afternoon storm activity on the red planet, with no new storm activity visible within a few thousand kilometers of either Mars rover site. Skies remained dusty and were expected to continue to clear slowly.
Sol-by-sol summary:
In addition to daily direct-from-Earth uplinks over the rover's high-gain antenna, relays to Earth at UHF frequences via the Odyssey orbiter, surveys of the sky and ground with the miniature thermal emission spectrometer, measurements of atmospheric opacity with the panoramic and navigation cameras, and image acquisition with the front and rear hazard avoidance cameras, Spirit completed the following activities:
Sol 1288 (Aug. 18, 2007): Spirit studied Norma Luker with the alpha-particle X-ray spectrometer.
Sol 1289: Spirit monitored dust accumulation on the rover mast, collected data on the external calibration target with the miniature thermal emission spectrometer, and completed a survey at high sun with the panoramic camera.
Sol 1290: Spirit surveyed the horizon with the panoramic camera and performed dust ejection maneuvers with the microscopic imager.
Sol 1291: Spirit took thumbnail images of the sky with the panoramic camera, checked for drift (changes with time) in the miniature thermal emission spectrometer, and acquired stereo microscopic images of Norma Luker. The rover moved the microscopic imager and acquired stereo microscopic views of surface ripples, stowed the robotic arm, and acquired hazard avoidance camera images to document the stowing of the arm.
Sol 1292: Plans for a day of remote sensing and acquisition of full-color images of a target known as "Eileen Dean" failed to get on board.
Sol 1293: Spirit checked for drift in the miniature thermal emission spectrometer, acquired movie frames in search of dust devils using the navigation camera, and took full-color images using all 13 filters of the panoramic camera of a target known as "Gertrude Weise12." The rover acquired miniature thermal emission spectrometer data from the same target before rolling a short distance away. After the short drive, the rover took images of its new location with the navigation camera and hazard avoidance cameras.
Sol 1294 (Aug. 24, 2007): Plans called for Spirit to check for drift in the miniature thermal emission spectrometer, acquire movie frames in search of dust devils with the navigation camera, and survey the horizon with the panoramic camera.
Odometry:
As of sol 1293 (Aug. 23, 2007), Spirit's total odometry was 7,154 meters (4.45 miles).
sol 1284-1287, August 20, 2007: Dust from Martian Sky Accumulates on Solar Panels
Even though the Martian sky above Gusev Crater continued to clear, solar power levels on NASA's Spirit rover remained fairly constant as dust settling from the atmosphere accumulated on top of the solar panels. Activities remained restricted. Measurements of atmospheric opacity, known as Tau, dropped from 3.6 on Martian day, or sol, 1283 (Aug. 12, 2007) to 3.3 on sol 1286 (Aug. 16, 2007), generating power levels of 301 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour).
During recent wind storms on Mars, some dust appears to have gotten past the cover of the microscopic imager, based on images Spirit acquired on sols 1279 and 1284-1286 (Aug. 8, 2007 and Aug. 14-16, 2007). Engineers conducting tests with a surrogate rover on Earth hoped to position the instrument in a downward-facing position as early as sol 1290 (Aug. 20, 2007) in an attempt to get accumulated dust to fall out.
While assessing the well-being of the microscopic imager, Spirit completed an analysis of a crushed rock target known as "Innocent Bystander" with the Mössbauer spectrometer and continued to make observations of the ground and atmosphere. The rover remains healthy and is parked just east of the elevated plateau known as "Home Plate."
The forecast for the next week is for no new dust storm activity, based on weather reports provided by Malin Space Science Systems, the builder of the Mars Color Imager on board the Mars Reconnaissance Orbiter. The camera is being used to monitor conditions on the red planet. Skies are expected to continue to clear over the next couple of months.
Sol-by-sol summary:
Except where noted, daily communications included morning, direct-from-Earth uplinks over the rover's high-gain antenna and evening relays of data to Earth at UHF frequences via the Odyssey orbiter. In addition, Spirit completed the following activities:
Sol 1284 (Aug. 13, 2007): Spirit placed the Mössbauer spectrometer back on Innocent Bystander and began analysis with the instrument. The rover also acquired images of ripples using the front and rear hazard avoidance cameras and microscopic images looking toward the sky through the dust cover of the microscopic imager. Spirit measured atmospheric opacity with the panoramic camera and surveyed the sky and ground with the miniature thermal emission spectrometer.
Sol 1285: Spirit surveyed atmospheric opacity with the panoramic and navigation camera and acquired images of ripples using the front and rear hazard avoidance cameras. The rover acquired microscopic images looking through the dust cover of the microscopic imager and surveyed the sky and ground with the miniature thermal emission spectrometer.
Sol 1286: Spirit surveyed the sky and ground with the miniature thermal emission spectrometer and measured atmospheric dust with the panoramic and navigation cameras. The rover continued with Mössbauer analysis of Innocent Bystander and took diagnostic images at different times of day looking skyward through the dust cover with the microscopic imager. Spirit surveyed the sky and ground with the miniature thermal emission spectrometer and acquired images with the front and rear hazard avoidance cameras.
Sol 1287 (Aug. 17, 2004): Spirit surveyed the sky and ground with the miniature thermal emission spectrometer and measured atmospheric dust with the panoramic and navigation cameras. The rover continued with Mössbauer analysis of Innocent Bystander and acquired images with the front and rear hazard avoidance cameras. Spirit took more skyward-oriented images through the dust cover with the microscopic imager and surveyed the sky and ground with the miniature thermal emission spectrometer.
Odometry:
As of sol 1287 (Aug. 16, 2007), Spirit's total odometry remained at 7,153 meters (4.44 miles).
sol 1274-1283, August 16, 2007: Gloomy Skies Show Signs of Clearing
Spirit is healthy as the amount of dust hoisted into the atmosphere by recent wind storms has leveled off and solar energy levels have held steady at about 280 to 300 watt-hours of energy (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). Since the rover's 1,271st Martian day, or sol, of exploration (July 31, 2007), atmospheric opacity, a measurement known as Tau, has stabilized at about 3.8. Given the apparent relative stability of the atmosphere, the rover's handlers have returned to somewhat more normal planning procedures, allowing the rover to take on more science activities. Spirit studied a crushed rock target known as "Innocent Bystander" using the Mössbauer spectrometer on sols 1275, 1278, and 1281 (Aug. 4, Aug. 7, and Aug. 10, 2007).
Spirit appears to have accumulated some dust contamination on the optics of the microscopic imager at some point during a period of 10 Martian days between sol 1257 (July 17, 2007) and sol 1277 (Aug. 6, 2007). On sol 1282 (Aug. 11, 2007), Spirit got a look at the microscopic imager with the dust cover closed using the panoramic and hazard avoidance cameras. The rover's handlers are considering using the front hazard avoidance cameras to try to get a better look at the microscopic imager with the dust cover open. They are also considering strategies for removing dust if necessary.
Spirit remains parked just to the east of the elevated plateau known as "Home Plate" with the Mössbauer spectrometer placed on Innocent Bystander.
Sol-by-sol summary:
Except where noted, daily communications included morning, direct-from-Earth uplinks over the rover's high-gain antenna and evening relays of data to Earth at UHF frequences via the Odyssey orbiter. In addition, Spirit completed the following activities:
Sol 1274 (Aug. 3, 2007): Spirit acquired wide-range, panoramic camera images for measuring atmospheric dust, searched for clouds using the navigation camera, acquired movie frames in search of dust devils, and acquired images of surface ripples to the front and rear of the rover with the hazard avoidance cameras. The rover surveyed the external calibration target with the miniature thermal emission spectrometer.
Sol 1275: Spirit conducted studies with the Mössbauer spectrometer, acquired a 3x1 mosaic of images of ripples with the navigation camera, acquired wide-range, panoramic camera images for measuring atmospheric dust, and took images of ripples with the front and rear hazard avoidance cameras. The rover scanned the sky and ground with the miniature thermal emission spectrometer.
Sol 1276: Spirit acquired images of ripples with the front and rear hazard avoidance cameras, acquired wide-range, panoramic camera images for measuring atmospheric dust, acquired a 360-degree panorama of the rover's surrounding with the navigation camera, and searched for clouds with the navigation camera.
Sol 1277: Spirit acquired a stack of microscopic images of targets known as "Stealing Second" and "Stealing Third," a microscopic image of Innocent Bystander, and both wide-range, panoramic camera images and navigation camera images for measuring atmospheric dust. The rover monitored dust on the rover mast, acquired images of ripples with the front and rear hazard avoidance cameras, and surveyed the sky and ground with the miniature thermal emission spectrometer.
Sol 1278: Spirit studied Innocent Bystander using the Mössbauer spectrometer, acquired images of ripples using the navigation camera, and measured atmospheric dust by acquiring wide-range, panoramic camera images as well as navigation camera images. The rover took thumbnail images of the sky and acquired movie frame images in search of dust devils with the navigation camera.
Sol 1279: Spirit acquired images of surface ripples using the rear and front hazard avoidance cameras, acquired a microscopic image looking through the dust cover, and acquired images of the microscopic imager from the outside using the panoramic and navigation cameras. The rover acquired wide-range, panoramic camera images as well as navigation camera images for measuring atmospheric dust, took spot images of the sky, and surveyed the horizon.
Sol 1280: Spirit measured atmospheric properties using the alpha-particle X-ray spectrometer and measured atmospheric opacity with the panoramic and navigation cameras. The rover took images of ripples with the front and rear hazard avoidance cameras, searched for clouds with the navigation camera, and conducted a mini-survey of the sky and ground with the miniature thermal emission spectrometer.
Sol 1281: Spirit acquired wide-range, panoramic camera images and navigation camera images to measure atmospheric dust. The rover conducted studies with the Mössbauer spectrometer, completed a survey at high sun with the panoramic camera, and took images of surface ripples using the navigation and panoramic cameras.
Sol 1282: Spirit extended the robotic arm for panoramic camera images, retracted the robotic arm for hazard avoidance camera images, and extended the rock abrasion tool into ready position. The rover acquired images of ripples using the front and rear hazard avoidance cameras, acquired wide-range, panoramic camera images to measure atmospheric dust, and monitored dust on the rover mast. Spirit conducted a mini-survey of the sky and ground using the miniature thermal emission spectrometer.
Sol 1283 (Aug. 12, 2007): Spirit acquired wide-range, panoramic camera images and navigation camera images for measuring atmospheric dust, took spot images of the sky, surveyed the horizon, acquired a 3x1 mosaic of navigation camera images of surface ripples, and completed a mini-survey of the sky and ground with the miniature thermal emission spectrometer.
Odometry:
As of sol 1283 (Aug. 12, 2007), Spirit's total odometry remained at 7,153 meters (4.44 miles).
sol 1268-1273, August 8, 2007: Martian Dust Begins to Settle -- Right on Top of the Solar Arrays
Spirit is healthy and continues to ride out the dust storms on Mars. In fact, atmospheric dreariness has improved in the last few Martian days, or sols, but as dust settles out of the atmosphere, it settles onto the solar arrays, keeping power levels relatively low.
Measurements of the amount of sunlight blocked from reaching the rover, known as Tau, dropped from a record high of 4.738 on sol 1265 (July 25, 2007) to 3.813 on sol 1273 (Aug. 2, 2007). Solar power levels leveled off at around 260 to 300 watt-hours per sol (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour).
Weather reports from the Mars Color Imager on the Mars Reconnaissance Orbiter indicate the storms may be in the early stages of decay. Spirit continues to use power conservatively in view of the recent jump in dust levels and the struggle for survival by Spirit's twin, the Opportunity rover, on the opposite side of the red planet.
Spirit remains parked just east of the elevated plateau known as "Home Plate," with the Mössbauer spectrometer placed on the target known as "Innocent Bystander." On sol 1273 (Aug. 2, 2007), Spirit performed a 5-hour study with the Mössbauer spectrometer.
After the dust settles, Spirit's handlers on Earth plan to have the rover continue collecting Mössbauer data from Innocent Bystander for a few sols, acquire microscopic images of the new dust layer on the soil, and drive onto Home Plate.
Sol-by-sol summary:
Except where noted, daily communications activities included morning, direct-from-Earth uplinks over the rover's high-gain antenna and evening relays of data to Earth at UHF frequences via the Odyssey orbiter. In addition, Spirit completed the following activities:
Sol 1268: Spirit measured atmospheric Tau with both the panoramic camera and navigation camera. The rover did not relay data to Earth to conserve power.
Sol 1269: Spirit measured Tau and completed a sky survey using the panoramic camera. The rover's handlers on Earth did not send instructions to the rover to conserve power.
Sol 1270: Spirit measured Tau and completed a sky survey using the panoramic camera. The rover's handlers on Earth did not send instructions to the rover to conserve power.
Sol 1271: Spirit measured Tau and completed a sky survey using the panoramic camera. The rover measured Tau using the navigation camera and acquired images of sand ripples on the surface with the front hazard avoidance camera.
Sol 1272: Spirit took more images of sand ripples with the front hazard avoidance camera as well as with the rear hazard avoidance camera. The rover acquired a mosaic of sand ripple images with the navigation camera. Spirit measured atmospheric dust, acquired images of the sky, completed a horizon survey, and acquired images of the "El Dorado" dune field with the panoramic camera. To conserve power, Spirit did not send data to Earth.
Sol 1273 (Aug. 2, 2007): Spirit studied Innocent Bystander with the Mössbauer spectrometer.
Odometry:
As of sol 1265 (July 25, 2007), Spirit's total odometry remained at 7,153 meters (4.44 miles).
sol 1261-1267, August 8, 2007: Atmospheric Gloom Reaches Record Levels
Despite setting new personal records for atmospheric opacity, Spirit is healthy and riding out the dust storm on Mars. Though science activity has been minimal, the rover was able to collect data on storm activity. On Spirit's 1,265th Martian day, or sol, of exploration (July 25, 2007), the rover reported an atmospheric opacity measurement, known as Tau, of 4.73 -- a record high for this vehicle. Solar power levels dropped to a corresponding record low of 261 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour).
Meanwhile, Spirit's handlers on Earth modified the rover's activities to reflect the reduced amount of power available. In some cases, this meant foregoing communications with the Mars Odyssey spacecraft.
Sol-by-sol summary:
Sol 1261-1263 (July 21-23, 2007): Spirit measured atmospheric opacity, known as Tau, once each sol using the panoramic camera. On sol 1261 (July 21, 2007), the rover transmitted a beep confirming the handover of a new master sequence of activities. There was no downlink of information from Spirit via UHF frequencies on sol 1263 (July 23, 2007).
Sol 1264: Spirit checked for drift (changes with time) in the miniature thermal emission spectrometer, acquired a micro-mini survey of the sky and ground using the miniature thermal emission spectrometer (meaning the scan lasted 6 1/2 minutes instead of 8 1/2 minutes), and meaasured atmospheric opacity using the panoramic camera.
Sol 1265: In the morning, Spirit measured atmospheric opacity with the panoramic camera and took images with the hazard avoidance cameras. Spirit checked for drift in the miniature thermal emission spectrometer and acquired a micro-mini survey of the sky and ground using the miniature thermal emission spectrometer.
Sol 1266: Spirit greeted the day by measuring atmospheric opacity with the panoramic camera and taking images with the hazard avoidance cameras. After receiving news of record-breaking tau, Spirit's handlers on Earth deleted a planned overnight study with the Mössbauer spectrometer. They transmitted activities for sol 1267.
Sol 1267 (July 27, 2007): Spirit measured atmospheric opacity with the panoramic camera, checked for drift in the miniature thermal emission spectrometer, and acquired a micro-mini survey of the sky and ground using the miniature thermal emission spectrometer. The rover surveyed the horizon with the panoramic camera. The next day, Spirit was to acquire images with the front hazard avoidance camera, measure atmospheric opacity with the panoramic camera, take images of the sky with the panoramic camera, and survey the sky and ground with the miniature thermal emission spectrometer.
Odometry:
As of sol 1265 (July 25, 2007), Spirit's total odometry remained at 7,153 meters (4.44 miles).
sol 1253-1260, August 8, 2007: Spirit Monitors Dust Storm While Studying Martian Terrain
Spirit is healthy and is parked next to a cluster of rock fragments known as "Innocent Bystander," which the rover has been studying "Innocent Bystander" using instruments on the rover's robotic arm, including a long analysis with the Mössbauer spectrometer. This target is of interest because it is high in silica, a feature suggesting water may have been present during formation. The rocks are also low in nanophase oxide, a possible product of weathering.
On the rover's 1,253rd Martian day, or sol, of exploration (July 13, 2007), Spirit took microscopic images of the aperture of the miniature thermal emission spectrometer while holding the microscopic imager itself, which is located at the end of the robotic arm, at different elevations. Spirit performed this experiment in preparation for running it again on Spirit's twin, the Opportunity rover, on the opposite side of Mars.
On sol 1,257 (July 17, 2007), Spirit acquired a super-resolution mosaic of microscopic images of Innocent Bystander to get a better look at the unusual granular texture of the surface.
Spirit recorded dust storm activity using the panoramic and navigation cameras.
The sky above Spirit continued to darken as a result of dust storm activity. Measurements of atmospheric opacity, known as Tau, are an estimate of how much sunlight cannot penetrate the atmosphere. During the week, Spirit recorded a Tau of 4.017 on sol 1,259 (July 19, 2007), the largest Tau to date at the rover's location. Spirit experienced a 6-percent dust cleaning of the rover's solar arrays on sol 1,258 (July 18, 2007), which left the solar arrays the cleanest they had been since sol 427 (March 16, 2005).
Sol-by-sol summary:
Sol 1253 (July 13, 2007): Spirit monitored atmospheric opacity using the panoramic camera, checked for drift (changes over time) in the miniature thermal emission spectrometer, and scanned the sky and ground using the miniature thermal emission spectrometer. Spirit took images of the miniature thermal emission spectrometer with the microscopic imager, exchanged tools to the Mössbauer spectrometer for an offset view of Innocent Bystander, and took thumbnail images of the sky using the panoramic camera. The rover acquired data from a target known as "Somp" using the miniature thermal emission spectrometer.
Sol 1254: In the morning, in addition to monitoring atmospheric opacity using the panoramic camera, Spirit took navigation cameras of the Sun, surveyed the horizon with the panoramic camera, and surveyed a target known as "Korus" using the miniature thermal emission spectrometer. Spirit checked for drift in the miniature thermal emission spectrometer and scanned the sky and ground using the miniature thermal emission spectrometer. The rover conducted Mössbauer studies of a target dubbed "Innocent Bystandar Offset2," acquired full-color panoramic camera images of a target known as "Tangor," and acquired super-resolution panoramic camera images of a target known as "Gooli." Spirit surveyed a target called "Gooli3" using the miniature thermal emission spectrometer.
Sol 1255: In the morning, Spirit took navigation camera images of the Sun, conducted a horizon survey with the panoramic camera, and acquired data from a target known as "Alice DeCambra," in addition to monitoring atmospheric opacity with the panoramic camera, checking for drift in the miniature thermal emission spectrometer, and scanning the sky and ground with the miniature thermal emission spectrometer. Spirit continued to collect Mössbauer data from Innocent Offset2, took thumbnail images of the sky with the panoramic camera, and acquired a mosaic of images of the dune field known as "El Dorado" with the panoramic camera. The rover used the miniature thermal emission spectrometer to collect data on targets known as "Mona Denton" and "Faget2."
Sol 1256: In the morning, Spirit took navigation camera images of the Sun and scanned Tangor with the miniature thermal emission spectrometer, in addition to monitoring atmospheric opacity with the panoramic camera, checking for drift in the miniature thermal emission spectrometer, and scanning the sky and ground with the miniature thermal emission spectrometer. Spirit continued Mössbauer studies of Innocent Bystander.
Sol 1257: In the morning, Spirit took navigation camera images of the Sun and used the miniature thermal emission spectrometer to study a target known as "Lenora Mandella2," in addition to monitoring atmospheric opacity with the panoramic camera, checking for drift in the miniature thermal emission spectrometer, and scanning the sky and ground with the miniature thermal emission spectrometer. Spirit acquired super-resolution, microscopic images of Innocent Bystander Offset2 and restarted the Mössbauer spectrometer for continued analysis of the same target.
Sol 1258: In the morning, Spirit monitored dust accumulation on the rover mast, took thumbnail images of the sky with the panoramic camera, checked for drift in the miniature thermal emission spectrometer, and scanned the sky and ground with the miniature thermal emission spectrometer. Spirit restarted the Mössbauer spectrometer for continued analysis of Innocent Bystander Offset2.
Sol 1259: Spirit started the day by acquiring thumbnail images of the sky in addition to checking for drift in the miniature thermal emission spectrometer and scanning the sky and ground with the miniature thermal emission spectrometer. Spirit acquired images with the hazard avoidance camera.
Sol 1260 (July 20, 2007): Shortly after sunup, Spirit scanned for dust devils by acquiring movie frames with the navigation camera. Spirit checked for drift in the miniature thermal emission spectrometer and scanned the sky and ground using the miniature thermal emission spectrometer. The next day, Spirit was to acquire a survey of the sky at high sun using the panoramic camera.
Odometry:
As of sol 1252 (July 12, 2007), Spirit's total odometry remained at 7,153 meters (4.44 miles).
sol 1247-1252, July 14, 2007: Spirit Examines Rocks Possibly Formed In Volcanic Gases or Hot Springs
Spirit is healthy after driving to a cluster of rock fragments known as "Innocent Bystander" (so named because Spirit accidentally ran over it when another rock, "Virginia Bell," was the intended target. The aim had been to crush Virginia Bell to expose a fresh surface for examination).
It was a fortuitous encounter, though, because indications are that Innocent Bystander may have been formed by either a fumarole or hot spring. A fumarole is a vent in the Earth's surface that emits steam and volcanic gases. Volcanic gases leach the original rock and leave silica-rich rock behind. If Innocent Bystander was created in a hot spring environment, then it could be siliceous sinter, a kind of silica-rich rock that precipitates directly from water.
Spirit had a solar-array dust-cleaning event on the rover's 1,252nd day, or sol, of Martian exploration (July 12, 2007). Even though Tau, a measurement of atmospheric opacity caused by dust, has been trending upward for the past several days, Spirit's solar power levels have risen slightly due to wind-related cleaning of the solar panels.
Sol-by-sol summary:
In addition to daily remote science observations of the atmosphere and terrain using the panoramic camera and the miniature thermal emission spectrometer, and communication activities including morning direct-from-Earth uplinks via the rover's high-gain antenna and evening downlinks at UHF frequencies via the Mars Odyssey orbiter, Spirit completed the following activities:
Sol 1247 (July 6, 2007): Spirit monitored atmospheric dust with the panoramic camera, scanned the sky and ground with the miniature thermal emission spectrometer, stowed the robotic arm, and drove to Innocent Bystander. Along the way, Spirit acquired mid-drive, full-color images of the work volume using all 13 filters of the panoramic camera as well as images with the hazard avoidance cameras. After transmitting data to the Odyssey orbiter, Spirit again measured atmospheric dust and took images of the sun with the navigation camera.
Sol 1248: In the morning, Spirit monitored atmospheric dust and surveyed the horizon with the panoramic camera, monitored dust on the rover mast, and acquired thumbnail images of the sky. Spirit then continued to measure atmospheric dust and scan the sky and ground with the miniature thermal emission spectrometer. The rover completed a calibration of the miniature thermal emission spectrometer as well as a survey of the sky and ground with the instrument. Spirit completed a survey at high Sun with the panoramic camera. After communicating with the Odyssey spacecraft, Spirit measured atmospheric dust.
Sol 1249: In the morning, Spirit monitored atmospheric dust with the panoramic camera, watched for dust devils, and acquired movie frames of potential dust devils with the navigation camera. Spirit continued to measure atmospheric dust opacity with the panoramic camera and scan the sky and ground witht the miniature thermal emission spectrometer. After the uplink to the Odyssey orbiter, Spirit continued to measure atmospheric opacity with the panoramic camera.
Sol 1250: In the morning, Spirit measured atmospheric opacity with the panoramic camera and surveyed the sky and ground with the miniature thermal emission spectrometer. Spirit checked for drift (changes with time) in the miniature thermal emission spectrometer. Spirit drove closer to Innocent Bystander and acquired post-drive images with the hazard avoidance cameras and a 360-degree panorama with the navigation camera. The rover continued to measure atmospheric opacity with the panoramic camera and scan the sky and ground with the miniature thermal emission spectrometer. After communicating with Odyssey, Spirit acquired navigation camera images of the Sun and again monitored atmospheric dust with the panoramic camera.
Sol 1238: In the morning, Spirit monitored dust build-up on the rover's mast, surveyed the horizon with the panoramic camera, and acquired movie frames with the navigation camera in search of dust devils. Spirit acquired microscopic images of the solar arrays, capture magnet, and filter magnet to document dust levels since the most recent dust-cleaning events on sols 1233 and 1234 (June 22-23, 2007). The rover acquired microscopic images of Eileen Dean and collected data on the target using the alpha-particle X-ray spectrometer. Spirit acquired four sets of comparative measurements with the miniature thermal emission spectrometer early in the day, in the afternoon, overnight, and early the next sol. Spirit observed the Sun with the navigation camera in support of the Mars Science Laboratory rover scheduled for launch in 2009. The goal of these observations is to see if navigation camera images of the sun can be used to orient the rover.
Sol 1251: Upon awakening, Spirit acquired images of the Sun using the navigation camera, measured atmospheric opacity with the panoramic camera, completed a survey of clasts using the panoramic camera, and surveyed the sky and ground with the miniature thermal emission spectrometer. Spirit continued to monitor atmospheric dust and scan the surroundings, then unstowed the robotic arm and acquired a 2x1x7 mosaic of microscopic images of Innocent Bystander. Spirit placed the alpha-particle X-ray spectrometer on Innocent Bystander, measured atmospheric dust and completed a survey at high Sun with the panoramic camera, and continued to monitor atmospheric dust and survey the surroundings. Spirit acquired thumbnail images of the sky using the panoramic camera, measured late atmospheric dust opacity, and scanned the calibration target and surveyed the sky and ground with the miniature thermal emission spectrometer. Spirit took a nap and awoke at 11:10 p.m. local Mars time to begin an alpha-particle X-ray study that was to last just under 12 hours.
Sol 1252 (July 12, 2007): After solar array wakeup, Spirit was slated to continue measuring atmospheric opacity with the panoramic camera, acquire images of the Sun with the navigation camera, and survey the sky and ground with the miniature thermal emission spectrometer.
Odometry:
As of sol 1250 (July 10, 2007), Spirit's total odometry remained at 7,153 meters (4.44 miles).
sol 1240-1246, July 14, 2007: Spirit Encounters First Big Dust Storm of the Season
Spirit has been dealing with the first big dust storm of the season. Tau, a measure of atmospheric opacity as an indicator of how much dust is in the atmosphere, jumped significantly, with a corresponding (and dismaying) drop in power.
At the start of the week, Tau was 1.076, corresponding to 34 percent direct sunlight and 750 watt-hours of energy. (A_watt-hour is the amount of energy in one watt of power working for one hour.) By the rover's 1,245th Martian day, or sol, of exploration (July 4, 2007), Tau had jumped to 2.437, corresponding to only 8.7 percent direct sunlight and 490 watt-hours of energy. Though there was little direct sunlight, there was a fair amount of scattered light to help augment the rover's power levels.
The storm resulted in several small cleaning and "dirtying" events, some of which removed and others of which deposited dust on the solar arrays. Individual changes have been small, though overall, slightly more dust accumulated than blew away.
To a person standing on Mars, the atmosphere would look somewhat like an overcast sky on Earth, perhaps with some dusty haze. The view would be noticeably darker than normal, with gray and slightly fuzzy shadows instead of the crisp shadows of a sunny day.
Despite the lower power levels -- and the even more conservative power estimates used for activity planning -- Spirit has managed to continue to investigate the silica-rich scuff in the rover's tracks nicknamed "Eileen Dean." The rover re-acquired microscopic images to replace the first, which were out of focus, and completed an analysis with both the Mössbauer spectrometer and the alpha-particle X-ray spectrometer.
Spirit is healthy. The rover's next destination is a target known as "Innocent Bystander," where the rover is slated to conduct further scientific analysis.
Sol-by-sol summary:
Sol 1240 (June 29, 2007): Spirit measured atmospheric dust opacity using the panoramic camera, acquired photometric data looking east toward the equator with the panoramic camera, acquired panoramic camera images of the external calibration target, acquired photometric data looking north (directly) toward the equator, and acquired panoramic camera images looking west toward the equator. Spirit again measured atmospheric dust opacity using the panoramic camera, acquired thumbnail images of the sky using the panoramic camera, and repeated the earlier scans of equatorial atmospheric conditions and the calibration target.
Sol 1241: Spirit measured atmospheric dust opacity using the panoramic camera, acquired photometric data looking east toward the equator with the panoramic camera, acquired panoramic camera images of the external calibration target, acquired photometric data looking north (directly) toward the equator, and acquired panoramic camera images looking west toward the equator. Spirit again measured atmospheric dust opacity using the panoramic camera, acquired thumbnail images of the sky using the panoramic camera, and repeated the earlier scans of equatorial atmospheric conditions and the calibration target.
Sol 1242: Spirit measured atmospheric dust opacity using the panoramic camera, acquired photometric data looking east toward the equator with the panoramic camera, acquired panoramic camera images of the external calibration target, acquired photometric data looking north (directly) toward the equator, and acquired panoramic camera images looking west toward the equator. Spirit again measured atmospheric dust opacity using the panoramic camera, acquired thumbnail images of the sky using the panoramic camera, and repeated the earlier scans of equatorial atmospheric conditions and the calibration target.
Sol 1243: Spirit measured atmospheric dust opacity using the panoramic camera, checked for drift (changes over time) in the miniature thermal emission spectrometer, surveyed the sky and ground with the miniature thermal emission spectrometer, and took thumbnail images of the sky using the panoramic camera. The rover made additional measurements of atmospheric dust opacity at different times of day using the panoramic camera, surveyed the ground and sky at different elevations using the miniature thermal emission spectrometer, and surveyed the sky at low sun with the panoramic camera.
Sol 1244: Upon the awakening of the rover's solar arrays, Spirit surveyed the sky and horizon with the panoramic camera, acquired movie frames with the navigation camera in search of dust devils, and surveyed the sky and ground with the miniature thermal emission spectrometer. The rover measured atmospheric opacity with the panoramic camera, checked for drift in the miniature thermal emission spectrometer, re-surveyed the sky and ground with the instrument, and acquired a 2x1x7 panorama of stereo microscopic images of Eileen Dean. Spirit changed tools to the Mössbauer spectrometer and used it to study Eileen Dean. Spirit acquired full-color images, using all 13 filters of the panoramic camera, of a target known as "Sorak." Spirit acquired images of the dune field known as "El Dorado" using the panoramic camera. The rover again measured atmospheric opacity with the panoramic camera, scanned the sky and ground with the miniature thermal emission spectrometer, surveyed Sorak and a target known as "Palthon2" with the miniature thermal emission spectrometer, and acquired photometric measurements with the panoramic camera. The rover again measured atmospheric opacity using the panoramic camera, acquired images of the sun with the navigation camera, surveyed the sky and ground with the miniature thermal emission spectrometer, and took more photometric measurements as well measurements of atmospheric opacity with the panoramic camera. Spirit acquired a mosaic of images of the sun with the navigation camera.
Sol 1245: After solar array wakeup, Spirit measured atmospheric opacity and acquired photometric measurements with the panoramic camera, surveyed the sky and ground with the miniature thermal emission spectrometer, and acquired thumbnail images of the sky with the panoramic camera. Spirit continued to measure atmospheric opacity with the panoramic camera, check for drift in the miniature thermal emission spectrometer, and survey the sky and ground with the miniature thermal emission spectrometer. The rover re-started the Mössbauer spectrometer for continued investigation of Eileen Dean, acquired full-color images of Palthon2 using all 13 filters of the panoramic camera, and surveyed targets known as "Sorapus" and "Manitalia" with the miniature thermal emission spectrometer. The rover continued to measure atmospheric opacity at different times of day and make photometric observations with the panoramic camera. Spirit took images of the sun with the navigation camera and surveyed the ground and sky at different elevations using the miniature thermal emission spectrometer.
Sol 1246 (July 5, 2007): Upon awakening, Spirit measured atmospheric opacity and acquired thumbnail images of the sky using the panoramic camera. Spirit surveyed the sky and ground with the miniature thermal emission spectrometer. Spirit surveyed a target known as "Naomi Meier" and checked for changes in measurements of darkness with the miniature thermal emission spectrometer. In addition to collecting ongoing measurements of atmospheric opacity and surveying the surroundings with the miniature thermal emission spectrometer, Spirit acquired stereo microscopic images of a target known as "Eileen_Dean2." Spirit switched tools to the alpha-particle X-ray spectrometer and placed it on Eileen_Dean2 before taking a nap. Upon re-awakening, the rover continued to measure atmospheric opacity and survey the surroundings. Spirit then took another nap, woke up at 11:10 p.m. local Mars time, and began a 12-hour analysis of Eileen_Dean2 using the alpha-particle X-ray spectrometer. Plans called for the rover to stop the analysis, measure atmospheric opacity, and scan the sky and ground the following morning.
Odometry:
As of sol 1246 (July 5, 2007), Spirit's total odometry remained at 7,147.93 meters (4.44 miles).
sol 1234-1239, July 02, 2007: Spirit Independently Approaches and Studies A Rock Outcrop
Spirit remains healthy after attempting to wrap up scientific studies on an outcrop that contains several tantalizing, high-silica targets. High-silica targets are of interest to scientists because water might have been involved in forming them. Spirit still has some work to do on two targets, known as "Eileen Dean" and "Innocent Bystander," before moving on to the elevated, circular plateau known as "Home Plate."
On Spirit's 1,235th sol, or Martian day of exploration (June 24, 2007), the rover successfully completed Step 4 of a new computer sequence called "IDD Autoplace." (IDD stands for Instrument Deployment Device, the technical name for the rover's robotic arm.) During the test, Spirit drove to a pre-selected target and autonomously gathered scientific data. The sequence enables the rover to select a substitute "target of opportunity" if the pre-selected target is out of range, which is exactly what happened during the first two tests.
Over the next month, Spirit will collect data in support of future Mars rover missions by taking images of the Sun each day with the navigation camera. These images are being used to develop an alternate method for orienting the rover.
Sol-by-sol summary:
In addition to daily remote science observations of the atmosphere and terrain using the panoramic camera and the miniature thermal emission spectrometer, and communication activities including morning direct-from-Earth uplinks via the rover's high-gain antenna and evening downlinks at UHF frequencies via the Mars Odyssey orbiter, Spirit completed the following activities:
Sol 1234 (June 23, 2007): Spirit acquired full-color images, using all 13 filters of the panoramic camera, of outcrop exposures known as "Virginia Bell," "Nancy Warren," and "Innocent Bystander." The rover acquired panoramic camera images of a target known as "Eileen Dean." Spirit surveyed several targets using the miniature thermal emission spectrometer, including "Mary Dailey," "NancyWarren3," "Dolores Moore," "Louella Daetweiler," "NancyWarren_background," "MaryDailey2," and "Eileen Dean."
Sol 1235: Upon awakening, Spirit surveyed the sky with the panoramic camera. Spirit then moved slightly closer to Eileen Dean. The rover completed Step 4 of the automatic targeting test by touching a spot that was offset from the target by about 5 centimeters (2 inches) with the Mössbauer spectrometer, acquiring a 1-by-1-by-seven mosaic of microscopic images, and placing the alpha-particle X-ray spectrometer on the spot and collecting data with the instrument. Spirit acquired navigation camera images and conducted a sky survey at low sun with the panoramic camera. Prior to the overpass of the Odyssey orbiter, the rover took images of the sky, known as "sky flats," for calibration purposes.
Sol 1236: Spirit used on-board software to watch for dust devils in addition to completing standard remote-science observations.
Sol 1237: Spirit rotated in place toward Eileen Dean, completing a final yaw, or pivot, of 42.8 degrees. Working autonomously, Spirit touched Eileen Dean with the Mössbauer spectrometer, acquired a 1-by-1-by-7 mosaic of microscopic images of the target, and completed alpha-particle X-ray spectrometer studies on the target. Spirit acquired images with the navigation camera. Spirit examined the rover's external calibration target with the miniature thermal emission spectrometer to verify that there was no dust contamination on the mirror as a result of recent dust-cleaning events related to Martian winds. Spirit acquired full-color images, using all 13 filters of the panoramic camera, of the rover's solar arrays, also to characterize changes in dust accumulation on the surface. Prior to the overpass of the Odyssey spacecraft, Spirit observed the Sun with the navigation camera in support of the Mars Science Laboratory rover scheduled for launch in 2009. The goal of these observations is to see if navigation camera images of the sun can be used to orient the rover.
Sol 1238: In the morning, Spirit monitored dust build-up on the rover's mast, surveyed the horizon with the panoramic camera, and acquired movie frames with the navigation camera in search of dust devils. Spirit acquired microscopic images of the solar arrays, capture magnet, and filter magnet to document dust levels since the most recent dust-cleaning events on sols 1233 and 1234 (June 22-23, 2007). The rover acquired microscopic images of Eileen Dean and collected data on the target using the alpha-particle X-ray spectrometer. Spirit acquired four sets of comparative measurements with the miniature thermal emission spectrometer early in the day, in the afternoon, overnight, and early the next sol. Spirit observed the Sun with the navigation camera in support of the Mars Science Laboratory rover scheduled for launch in 2009. The goal of these observations is to see if navigation camera images of the sun can be used to orient the rover.
Sol 1239 (June 28, 2007): The activities for this day were mostly a repeat of those of the previous sol, except for the four sets of measurements with the miniature thermal emission spectrometer. Spirit acquired 15 hours and 23 minutes of data from Eileen Dean using the alpha-particle X-ray spectrometer.
Odometry:
As of sol 1237 (June 26, 2007), Spirit's total odometry was 7,147.93 meters (4.44 miles).
sol 1226-1233, June 27, 2007: Spirit's Solar Power Levels Continue to Rise
Spring cleaning continued on NASA's Spirit rover, as atmospheric turbulence on Mars cleared away more dust from the solar panels on the rover's 1,233rd sol, or Martian day, of exploration (June 22, 2007). As a result of this most recent dust-clearing event, Spirit out-produced the electrical energy of Spirit's twin, the Opportunity rover on the opposite side of Mars, by about 50 watt-hours. (That's the amount of electricity needed to burn a 50-watt light bulb for one hour.) Tau measurements estimating the amount of dust in the atmosphere rose from 0.69 to 0.75. (Perfectly clean solar arrays would have a dust factor of 1.0, so the larger the dust factor, the cleaner the arrays.) Electrical energy rose to 738 watt-hours.
In addition, Spirit investigated an unbrushed rock outcrop known as "Nancy Warren," a candidate high-silica target. On sols 1226, 1227, and 1228 (June 15-17, 2007), the rover worked on a second investigation intended to study the brushed surface of the rock. Because the rover did not complete the brushing operation, Spirit ended up taking a second set of measurements that was identical to the first.
On the rover's 1,232nd sol of exploration (June 21, 2007), Spirit attempted to scuff a rock target known as "Virginia Bell" but didn't quite reach it and ended up scuffing a soil exposure about 15 centimeters (6 inches) away, creating a new target that scientists dubbed "Innocent Bystander."
Sol-by-sol summary:
In addition to daily observations of atmospheric dust levels using the panoramic camera, surveys of the sky and ground using the miniature thermal emission spectrometer, and communication activities including morning direct-from-Earth uplinks via the rover's high-gain antenna and evening downlinks at UHF frequencies via the Mars Odyssey orbiter, Spirit completed the following activities:
Sol 1226: Spirit placed the rock abrasion tool on Nancy Warren, placed the alpha-particle X-ray spectrometer on the target, collected data with the instrument, and completed an overnight transmission of data to the Odyssey orbiter.
Sol 1227: Spirit acquired a mosaic of microscopic images of Nancy Warren, placed the Mössbauer spectrometer on the target, and acquired data with the instrument. The rover acquired images of the spacecraft deck with the navigation camera. Spirit conducted reconnaissance and surveyed targets known as "Patricia Courtney," "Lenora Mandella," "Barbara Rotvig," and "Pauline Crawley" with the miniature thermal emission spectrometer. The rover scanned for clouds using the navigation camera and monitored dust on the rover mast.
Sol 1228: Spirit continued to study Nancy Warren using the Mössbauer spectrometer. The rover acquired a full-color panorama of light-colored wheel tracks using all 13 filters of the panoramic camera. Spirit conducted reconnaissance and surveyed the tracks as well as targets known as "Shirley Crites," "Betty McKenna," and "Naomi Meier" using the miniature thermal emission spectrometer. The rover completed an overnight transmission of data to the Odyssey orbiter and acquired an eastward-looking mosaic of images using the navigation camera.
Sol 1229: Spirit continued analysis of Nancy Warren using the Mössbauer spectrometer. The rover acquired images of the spacecraft deck with the panoramic camera to document the previous week's dust-cleaning event that occurred on sol 1224 (June 13, 2007). Spirit acquired movie frames with the navigation camera in search of dust devils.
Sol 1230: Spirit acquired microscopic images of the solar arrays, the dust capture magnet, and the filter magnet, along with panoramic camera images of the solar arrays, to document the dust-cleaning event of sol 1224 (June 13, 2007). The rover acquired microscopic images of undisturbed soil near the silica-rich outcrop known as Nancy Warren along with data using the alpha-particle X-ray spectrometer. Members of the science team hope to use the data to characterize local soil that might be contaminating the outcrop.
Sol 1231: Spirit resumed measurements of Nancy Warren using the Mössbauer spectrometer. The rover surveyed targets on Nancy Warren known as "Gertrude Weise," "Naomi Meier," "Rykors," "Silian," "Sith," "Skeel," "Sompus," and "Betty Jane Comet" using the miniature thermal emission spectrometer.
Sol 1232: Spirit acquired microscopic images of a target called "Darlene Mickelson" and attempted to crush the outcrop in the vicinity of Virginia Bell by driving over it to expose more silica-rich outcrop material. The rover acquired post-drive images of the target area using the navigation camera.
Sol 1233: Spirit acquired movie frames in search of morning dust devils using the navigation camera and surveyed the post-crush target area using the miniature thermal emission spectrometer.
Odometry:
As of sol 1232 (June 21, 2007), Spirit's total odometry was 7,143.87 meters (4.44 miles).
sol 1219-1225, June 18, 2007: Spirit's Solar Panels Get Spring Cleaning
Spirit got a second spring cleaning on Mars with a dust-cleaning event that increased power from the rover's solar arrays by 120 watt-hours (a 100-watt light bulb that burns for one hour uses 100 watt-hours of electricity). Spirit previously experienced dust-lifting winds in 2005. Energy from the rover's solar arrays is now higher than 600 watt-hours.
After completing scientific studies of rock exposures known as "Betty Wagoner" and "Elizabeth Emery," Spirit drove to another rock target called "Nancy Warren" to conduct studies with instruments on the rover's robotic arm, including the microscopic imager, the alpha-particle X-ray spectrometer, the brush on the rock abrasion tool, and the Mössbauer spectrometer. The next destination on Spirit's itinerary is the "on-ramp" of the elevated plateau-like feature known as "Home Plate."
Sol-by-sol summary:
In addition to daily observations of atmospheric dust levels using the panoramic camera, surveys of the sky and ground using the miniature thermal emission spectrometer, and communication activities including morning direct-from-Earth uplinks via the rover's high-gain antenna and evening downlinks at UHF frequencies via the Mars Odyssey orbiter, Spirit completed the following activities:
Sol 1219 (June 8, 2007): Spirit touched a rock exposure adjacent to Betty Wagoner known as "Betty Wagoner's Daughter" with the rock abrasion tool, brushed it, acquired a mosaic of microscopic images, touched the target with the Mössbauer spectrometer, and acquired more microscopic images. The rover placed the Mössbauer spectrometer back on Elizabeth Emery and collected data with the instrument, watched for dust devils, and completed an overnight relay of data to the Odyssey orbiter.
Sol 1220: Spirit acquired full-color images of the work area reachable by the robotic arm using all 13 filters of the panoramic camera and watched for morning dust devils. The rover also acquired full-color images using all 13 filters of the panoramic camera of targets known as "Melba Alspaugh," "Helen St. Aubin," and "Ruth Lessing." The rover acquired data using the miniature thermal emission spectrometer from targets known as "Melba Alspaugh2," "Betty Whiting2," "Joan Chiancola," and "Helen St. Aubin2." Spirit watched for dust devils, surveyed a target called "Jean Gilchrist" with the miniature thermal emission spectrometer, and completed an overnight transfer of data to the Odyssey spacecraft.
Sol 1221: Spirit acquired spot images of the sky with the panoramic camera and drove toward Nancy Warren. The rover acquired image mosaics with the navigation camera and panoramic camera and completed an overnight tranmission of data to Odyssey.
Sol 1222: Spirit conducted a survey of rock clasts with the panoramic camera, scanned the sky for clouds with the navigation camera, and acquired movie frames in search of dust devils with the navigation camera. The rover acquired systematic foreground images using all 13 filters of the panoramic camera and a systematic foreground raster with the miniature thermal emission spectrometer. Spirit again watched for dust devils and acquired movie frames with the navigation camera. The rover measured atmospheric argon using the alpha-particle X-ray spectrometer. Spirit surveyed the horizon with the panoramic camera and monitored dust on the rover's mast.
Sol 1223: Spirit completed a reconnaissance study of the rover's tracks using the miniature thermal emission spectrometer. The rover surveyed Nancy Warren with the miniature thermal emission spectrometer, approached Nancy Warren, and acquired post-drive image mosaics with the navigation camera. The rover completed an overnight relay of data to the Odyssey orbiter.
Sol 1224: Spirit acquired thumbnail images of the sky using the panoramic camera and conducted a high-sun survey with the panoramic camera. Spirit conducted reconnaissance with the miniature thermal emission spectrometer and completed an overnight relay of data to the Odyssey spacecraft.
Sol 1225 (June 14, 2007): Spirit unstowed the robotic arm, acquired a mosaic of microscopic images of Nancy Warren, placed the alpha-particle X-ray spectrometer on the target, and acquired data with the instrument. Spirit relayed data overnight to Odyssey.
Odometry:
As of sol 1225 (June 14, 2007), Spirit's total odometry was 7,141.67 meters (4.44 miles).
sol 1207-1218, June 11, 2007: Spirit Studies Layered Rocks at 'Home Plate'
Having completed studies of bright, silica-rich soil deposits at a target known as "Gertrude Weise," Spirit drove to a perch on the eastern edge of the circular, plateau-like feature known as "Home Plate" and began studying its stratigraphy. Spirit will next drive back in the direction of Gertrude Weise to study another nearby outcrop. The nearby outcrop, known as "Nancy Warren," appears similar to a previously studied outcrop known as "Elizabeth Mahon" that had a silica content of approximately 72 percent, somewhat lower than the 90-percent silica measaured at Gertrude Weise.
A layer of dark soil on Elizabeth Mahon likely affected the measurement of silica content with the alpha-particle X-ray spectrometer, which measures the abundance of chemical elements. Nancy Warren is interesting because it appears to have less of the dark soil coating than Elizabeth Mahon and could help scientists characterize the silica found at Gertrude Weise.
Sol-by-sol summary:
In addition to daily observations of atmospheric dust levels using the panoramic camera, surveys of the sky and ground using the miniature thermal emission spectrometer, and communication activities including morning direct-from-Earth uplinks via the rover's high-gain antenna and evening downlinks at UHF frequencies via the Mars Odyssey orbiter, Spirit completed the following activities:
Sol 1207 (May 26, 2007): Spirit re-started the Mössbauer spectrometer and continued analysis of a rock target known as "Pesapallo," representing one of the lowest stratigraphic units of Home Plate. Spirit surveyed targets known as "Margaret Brown" and "Edythe Keating" with the miniature thermal emission spectrometer. Spirit acquired movie frames in search of dust devils with the navigation camera in coordination with orbital scans of the terrain by the High Resolution Science Imaging Experiment on board the Mars Reconnaissance Orbiter. The rover acquired an image mosaic of a target called "Bullpen2" using the panoramic camera and searched for clouds using the navigation camera.
Sol 1208: Spirit acquired data from targets known as "Mary Reynolds" and "Eleanor Callow" with the miniature thermal emission spectrometer and re-started analysis of Pesapallo using the Mössbauer spectrometer. The rover completed an overnight relay of data to the Odyssey orbiter and acquired an image mosaic of a target called "Bullpen3" with the panoramic camera.
Sol 1209: Spirit used the rock abrasion tool to brush the surface of "Superpesis," a rock target on another fin-shaped outcrop of Home Plate, acquired stereo microscopic images of the target, and analyzed the target with the alpha-particle X-ray spectrometer. Spirit acquired movie frames in search of dust devils using the navigation camera.
Sol 1210: Spirit stowed the robotic arm, bumped backward, and acquired full-color images of Pesapallo using all 13 filters of the panoramic camera. Spirit drove 3 meters (10 feet) to a rock target known as "June Emerson," acquired post-drive images with the navigation camera, and took spot images of the sky with the panoramic camera.
Sol 1211: Spirit unstowed the robotic arm, brushed the surface of June Emerson with the rock abrasion tool, acquired microscopic images of June Emerson, and placed the alpha-particle X-ray spectrometer on the target. The rover surveyed additional targets known as "Dorothy Cameron" and "Adeline Kerrar" using the miniature thermal emission spectrometer. Spirit then acquired data from June Emerson using the alpha-particle X-ray spectrometer. The rover completed an overnight relay of data to the Odyssey orbiter, acquired full-color images of Dorothy Cameron using all 13 filters of the panoramic camera, and scanned the sky for clouds using the navigation camera.
Sol 1212: Spirit acquired microscopic images of rock targets called "Dorothy Key" and "Betty Foss." The rover placed the Mössbauer spectrometer on June Emerson and collected data. Spirit used the miniature thermal emission spectrometer to study rock targets known as "Helen Staubin" and "Dorothy Chapman" and completed an overnight relay of data to the Odyssey orbiter. Spirit acquired panoramic camera images of the solar array to monitor dust accumulation.
Sol 1213: Spirit acquired more data from June Emerson using the Mössbauer spectrometer and acquired data using the miniature thermal emission spectrometer from Pesapallo and targets known as "Joan Chiancola," "Jaynie Krick," and "Jean Gilchrist." Spirit acquired panoramic camera images of the rover's tracks and full-color images using all 13 filters of the panoramic camera of Jean Gilchrist and Jaynie Krick. The rover completed an overnight relay of data to the Odyssey orbiter and watched for dust devils.
Sol 1214: Spirit continued to acquire data from June Emerson using the Mössbauer spectrometer. Using the panoramic camera and the miniature thermal emission spectrometer, the rover acquired full-color images and thermal data to characterize rock targets known as "Irene Kotowicz," "Audrey Seitzinger," "Lucille Colacio," and "Mary Kustra." Spirit watched for dust devils and completed an overnight relay of information to the Odyssey orbiter. Spirit stowed the robotic arm and acquired full-color images of the reachable work volume using the panoramic camera. The rover took spot images of the sky using the panoramic camera and conducted reconnaissance using the miniature thermal emission spectrometer.
Sol 1215: Spirit drove 1.2 meters (3.9 feet) to a finely crossbedded rock target dubbed "Elizabeth Emery" and acquired post-drive navigation camera images. The rover watched for dust devils, relayed data overnight to the Odyssey spacecraft, surveyed the horizon with the panoramic camera, and did reconnaissance using the miniature thermal emission spectrometer.
Sol 1216: Spirit unstowed the robotic arm and conducted a study of Elizabeth Emery with the brush on the rock abrasion tool, the microscopic imager, and the alpha-particle X-ray spectrometer. The rover surveyed targets known as "Clara Cook" and "Ruth Lessing" with the miniature thermal emission spectrometer, relayed data overnight to the Odyssey orbiter, and acquired thumbnail images of the sky using the panoramic camera.
Sol 1217: Spirit brushed a finely crossbedded rock target known as "Jane Stoll" using the rock abrasion tool and took microscopic images of the brushed target. The rover placed the Mössbauer spectrometer back on Elizabeth Emery and collected more data. Spirit acquired full-color, 13-filter images of Dorothy Chapman with the panoramic camera and data from Jaynie Krick using the miniature thermal emission spectrometer. The rover completed an overnight relay to the Odyssey spacecraft.
Sol 1218 (June 7, 2007): Spirit acquired early-morning panoramic camera images and movie frames in search of dust devils. The rover used the rock abrasion tool to brush the surface of rock targets called "Mildred Deegan" and "Betty Wagoner" and took microscopic images of the brushed surfaces. Spirit surveyed Irene Kotowicz with the miniature thermal emission spectrometer, completed an overnight relay of data to the Odyssey orbiter, searched for clouds using the navigation camera, and acquired images of a target known as "Donna Cook" with the panoramic camera.
Odometry:
As of sol 1218 (June 7, 2007), Spirit's total odometry was 7,124.92 meters (4.43 miles).
sol 1200-1206, May 31, 2007: Remarkable Rover Continues to Astonish
Spirit is still making new discoveries despite dragging its feet, so to speak, after losing use of the right front wheel 426 sols, or Martian days, ago. In the process of creating small trenches while traversing Martian terrain, the dragging right front wheel revealed one of the most astonishing discoveries so far -- exceptionally high silica content in Martian soil, indicative of water at some point in the past. Two of Spirit's scientific instruments -- the alpha-particle X-ray spectrometer and the miniature thermal emission spectrometer -- measured a composition of about 90 percent pure silica in a soil target known as "Gertrude Weise."
Sol-by-sol summary:
In addition to daily observations of atmospheric dust levels using the panoramic camera and surveys of the sky and ground using the miniature thermal emission spectrometer, Spirit completed the following activities:
Sol 1200 (May 19, 2007): Spirit started a 23.25-hour study with the Mössbauer spectrometer and surveyed the rover's tracks as well as targets known as "Josephine Kabick," "Nalda Phillips1," "Nalda Phillips2," "Marilyn Olinger," and "Eileen Burmeister" with the miniature thermal emission spectrometer.
Sol 1201: Spirit watched for morning dust devils, stowed the robotic arm, and bumped backward in 60-centimeter (24-inch) "steps," or intervals. After each step, Spirit scuffed the soil with the left front wheel by rotating the wheel 180 degrees. The rover did this for a distance of 4.19 meters (13.8 feet). After the drive, Spirit acquired images of the scuffed terrain and the terrain ahead with the navigation camera.
Sol 1202: Spirit completed a survey at high sun using the panoramic camera. Spirit acquired panoramic camera images of the scuffed area and surveyed Gertrude Weise with the miniature thermal emission spectrometer. The rover searched for dust devils by acquiring navigation camera movies in coordination with overhead observations by the High Resolution Science Imaging Experiment on board the Mars Reconnaissance Orbiter.
Sol 1203: Spirit monitored dust on the rover mast and watched for dust devils in the morning. Spirit acquired navigation camera images before driving 6.68 meters (21.9 feet) around obstacles en route to "Home Plate." After the drive, Spirit acquired images with the hazard avoidance cameras and navigation camera.
Sol 1204: Spirit spent the first part of the sol analyzing the rover's external calibration target with the miniature thermal emission spectrometer, searching for clouds with the navigation camera, and acquiring movies in search of dust devils with the navigation camera. The rover then acquired image mosaics of the dune field known as "El Dorado" with the panoramic camera in addition to systematic foreground data with the miniature thermal emission spectrometer. Spirit acquired navigation camera images, searched again for dust devils, and acquired more panoramic camera images.
Sol 1205: Spirit completed a systematic ground survey with the panoramic camera, unstowed the robotic arm, brushed the surface of a target known as "Pesapallo," acquired stereo microscopic images of the surface, then placed the alpha-particle X-ray spectrometer on it. Spirit acquired data with the alpha-particle X-ray spectrometer for 18.75 hours.
Sol 1206 (May 25, 2007): Spirit searched for morning dust devils, retracted the robotic arm, and placed the Mössbauer spectrometer on Pesapallo. The rover acquired Mössbauer spectrometer data for 23 hours. Spirit acquired panoramic camera images of a target known as "Bullpen" and miniature thermal emission spectrometer data from a target known as "Joyce Steel." The following morning, Spirit was scheduled to conduct a survey of the horizon with the panoramic camera in addition to studies with the miniature thermal emission spectrometer.
Odometry:
As of sol 1204 (May 23, 2007), Spirit's total odometry was 7,120.34 meters (4.42 miles).
sol 1193-1199, May 24, 2007: Spirit Continues Soil Analysis
Spirit is healthy and spent the last week studying light and dark soil in and around the rover's tracks between "Home Plate" and "Mitcheltree Ridge." Spirit collected additional soil data, including about 24 hours of data using the alpha-particle X-ray spectrometer and 70 hours of data using the Mössbauer spectrometer. The primary soil targets examined during the week are known as "Kenosha Comets" and "Lefty Ganote."
Sol-by-sol summary:
In addition to daily observations of atmospheric dust levels using the panoramic camera and surveys of the sky and ground using the miniature thermal emission spectrometer, Spirit completed the following activities:
Sol 1193 (May 12, 2007): Spirit acquired alpha-particle X-ray spectrometer data from Kenosha Comets, miniature thermal emission spectrometer data from a target called "Alice Blaski," and panoramic camera images of Alice Blaski and another target known as "Mantalia." Following those tasks, Spirit napped until 11 p.m. local Mars time. Spirit then conducted a 12-hour analysis of Kenosha Comets using the alpha-particle X-ray spectrometer.
Sol 1194: Spirit started the day with acquisition of full-color images of light-colored tracks using all 13 filters of the panoramic camera. The rover acquired thumbnail images of the sky with the panoramic camera. Spirit replaced the alpha-particle X-ray spectrometer with the Mössbauer spectrometer and acquired 23.3 hours of Mössbauer data from Kenosha Comets. The rover studied a target known as "Palthon" using the miniature thermal emission spectrometer and took thumbnail images of the Martian sky with the panoramic camera.
Sol 1195: Spirit acquired another 23.3 hours worth of Mössbauer data from Kenosha Comets as well as a movie in search of dust devils using the navigation camera. The rover studied Mantalia and another target known as "Orluk" using the miniature thermal emission spectrometer.
Sol 1196: Spirit's first task of the day was to complete a sky survey using the panoramic camera. The rover stowed the robotic arm, drove backward 0.85 meters (2.8 feet), and autonomously put the alpha-particle X-ray spectrometer in position for further studies. Spirit acquired hazardous avoidance camera images prior to and after stopping and acquired navigation camera images of the terrain. Starting at 11 p.m. local Mars time, Spirit conducted an 11-hour study of the Martian atmosphere using the alpha-particle X-ray spectrometer.
Sol 1197: Spirit began the day by searching the Martian sky for clouds using the navigation camera and surveying the horizon with the panoramic camera. Spirit acquired full-color, 13-filter images of "Gertrude Weise background 3" using the panoramic camera. The rover surveyed Kenosha Comets and targets known as "Gertrude Weise background 2," "Kay Blumetta," and Gertrude Weise background 3 using the miniature thermal emission spectrometer.
Sol 1198: In the morning, Spirit acquired full-color images of Kenosha Comets using all 13 filters of the panoramic camera. The rover acquired a 360-degree panorama using the navigation camera. Spirit unstowed the robotic arm, acquired microscopic images of Lefty Ganote, and placed the alpha-particle X-ray spectrometer on Lefty Ganote. Spirit surveyed a target known as "Audrey Wagner," Kenosha Comets, and two targets in the rover's tracks known as "Tracks No. 1" and "Tracks No. 2" using the miniature thermal emission spectrometer. The rover completed a sky survey at low sun with the panoramic camera. After napping, Spirit awoke at 11 p.m. local Mars time and conducted an overnight study using the alpha-particle X-ray spectrometer that lasted 11 hours and 52 minutes.
Sol 1199 (May 18, 2007): Plans called for Spirit to begin the day with a search for dust devils using the navigation camera and a survey of a target called "Margaret Jones" using the miniature thermal emission spectrometer. After that, the rover was to place the Mössbauer spectrometer on Lefty Ganote and conduct a 23 1/4 - hour analysis, acquire full-color images of targets called "Ethel Boyce" and "Joanne Weaver" using all 13 filters of the panoramic camera, and conduct another search for dust devils the following morning by collecting movie frames with the navigation camera.
Odometry:
As of sol 1198 (May 17, 2007), Spirit's total odometry was 7,109.47 meters (4.42 miles).
sol 1186-1192, May 14, 2007: Spirit Continues Studies of Interesting Material Near 'Home Plate'
Spirit is healthy and has finished investigating a patch of churned-up, white-toned, silica-rich material known as "Gertrude Weise."
Meanwhile, the rover's first attempt to autonomously place the Mössbauer spectrometer on a target was successful. Spirit backed up over Gertrude Weise to a spot 2 meters (6.6 feet) beyond it and placed the Mössbauer spectrometer on the target. Spirit did not immediately follow up with placement of the microscopic imager on the target to avoid potential collisions.
Plans called for Spirit to coordinate searching for dust devils on the ground with overhead scans of terrain by the Mars Reconnaissance Orbiter on sol 1191 (May 10, 2007). Also on sol 1191, the rover was to combine searching for dust devils with searching for clouds. This activity was meant as a stress test, as Spirit has already successfully completed such searches independently.
Sol-by-sol summary:
In addition to daily observations of atmospheric dust levels with the panoramic camera and surveys of the sky and ground using the miniature thermal emission spectrometer, Spirit conducted the following activities:
Sol 1186 (May 5, 2007): Spirit acquired full-color, 13-filter images of a target called "Kathryn Beare" using the panoramic camera and studied Kathryn Beare and targets known as "GertrudeWeise2" and "Janice Ohara" using the miniature thermal emission spectrometer.
Sol 1187: Spirit acquired full-color, 13-filter images of Gertrude Weise, drove 5 meters (16 feet) to approach the soil target, and autonomously placed the Mössbauer spectrometer on target. The rover acquired a 360-degree panorama of the terrain using the navigation camera and also acquired a mosaic of images using the panoramic camera.
Sol 1188: Spirit took thumbnail images of the sky using the panoramic camera before spending the afternoon recharging the battery with energy from the rover's solar array.
Sol 1189: Spirit acquired movies and searched for dust devils using the navigation camera and touched a surface with the Mössbauer spectrometer. Spirit then began analysis of a target called "Kenosha Comets," collecting microscopic images and placing the alpha-particle X-ray spectrometer on the target. The rover acquired data from targets known as "Virginia Bell" and "Nancy Warren" using the miniature thermal emission spectrometer. After exchanging data with the Odyssey orbiter, Spirit conducted a 12-hour, overnight analysis of Kenosha Comets using the alpha-particle X-ray spectrometer.
Sol 1190: Spirit began the day acquiring a full-color, 13-filter panorama of Virginia Bell using the panoramic camera. The rover switched tools from the alpha-particle X-ray spectrometer to the Mössbauer spectrometer for continued study of Kenosha Comets. The rover acquired data from a target known as "Thelma Hundeby" before conducting a 23-hour, overnight study of Kenosha Comets with the Mössbauer spectrometer.
Sol 1191: Plans called for Spirit to acquire panoramic-camera movies in search of dust devils in tandem with overhead scans of terrain by the High-Resolution Imaging Science Experiment on the Mars Reconnaissance Orbiter. Plans also called for the rover to search for clouds, study Gertrude Weise with the Mössbauer spectrometer, and acquire full-color, 13-filter images of a target known as "Muriel Bevis" and of the horizon with the sun halfway below it.
Sol 1192 (May 11, 2007): Plans called for Spirit to stop the Mössbauer spectrometer, survey the rover's calibration target and tracks with the miniature thermal emission spectrometer, conduct a low-sun survey, analyze Gertrude Weise and another target known as "Elizabeth Mahon" with the Mössbauer spectrometer, and survey Muriel Bevis using the miniature thermal emission spectrometer. The rover was to acquire panoramic camera images of the calibration target and conduct a low-sun survey of "McCool Hill." The following morning, Spirit was to acquire thumbnail images of the sky using the panoramic camera and survey a target known as "Marie Wegman" using the miniature thermal emission spectrometer.
Odometry:
As of sol 1187 (May 6, 2007), Spirit's total odometry was 7,108.60 meters (4.42 miles).
sol 1179-1185, May 6, 2007: Spirit Examined Light--Colored Material Near 'Home Plate'
Spirit is healthy and has completed its investigation of a knobby rock target known as "GoodQuestion."
Next on Spirit's itinerary is a drive to the north and an attempt to climb onto "Home Plate." On the way, Spirit will examine white--toned material where one of the rover's wheels disturbed the soil. Observations using the miniature thermal emission spectrometer suggest it may be enriched in silica, similar to the "Elizabeth Mahon" rock outcrop the rover studied last week. Science team members have nicknamed the soil target "Gertrude Weise."
Sol-by-sol summary:
In addition to daily observations of atmospheric dust levels and surveys of the sky and ground using the miniature thermal emission spectrometer, Spirit conducted the following activities:
Sol 1179 (April 28, 2007): Spirit acquired panoramic camera images of targets known as "Gooli" and "Joyce Ricketts," surveyed Gooli and a target known as "Yolande Schick" with the miniature thermal emission spectrometer, and studied GoodQuestion using the alpha--particle X--ray spectrometer.
Sol 1180: Spirit surveyed the horizon with the panoramic camera, watched for dust devils, studied GoodQuestion with the Mössbauer spectrometer, and acquired panoramic camera images of GoodQuestion. The rover also surveyed a target known as "Joan Sindelar."
Sol 1181: Spirit acquired panoramic camera images of a target known as "Everett" and studied GoodQuestion using the Mössbauer spectrometer. The rover acquired panoramic camera images of a target called "Yolanda Schick."
Sol 1182: Spirit recorded a movie in search of dust devils using the navigation camera and studied light--toned soil using the miniature thermal emission spectrometer. Spirit drove 1.9 meters (6.2 feet) to the new science target, Gertrude Weise. The rover acquired mid--drive images with the navigation camera in support of observations of GoodQuestion with the miniature thermal emission spectrometer, then made those same observations. After the drive, the rover acquired more images with both the navigation and panoramic cameras.
Sol 1183: Spirit monitored dust on the rover mast, surveyed Gertrude Weise with the miniature thermal emission spectrometer, and acquired full--color images of GoodQuestion using all 13 filters of the panoramic camera. Spirit acquired super--resolution images of a target known as "Fern Shollenberger" with the panoramic camera. The rover studied targets nicknamed "Philomena Zale," "Alma Ziegler," and "Ruth Heverly" using the miniature thermal emission spectrometer.
Sol 1184: Spirit watched for dust devils in the morning and checked for drift (changes over time) in the miniature thermal emission spectrometer. Spirit drove 6.7 meters (22 feet) to a target called "White Soil." The rover acquired post--drive images with both the navigation camera and the panoramic camera.
Sol 1185 (May 4, 2007): Plans called for Spirit to watch for dust devils in the morning and complete a systematic foreground study with the miniature thermal emission spectrometer. The rover was also to acquire navigation camera images in support of observations with the miniature thermal emission spectrometer, conduct a study of atmospheric argon using the alpha--particle X--ray spectrometer, and watch for dust devils and take panoramic images of the sky the next morning.
Odometry:
As of sol 1184 (May 3, 2007), Spirit's total odometry was 7,103 meters (4.4 miles).
sol 1172-1178, May 1, 2007: Spirit Discovers Changes in Soil Near 'Home Plate'
Spirit remains healthy after completing scientific investigation of a light-toned soil patch nicknamed "Everett." Everett is interesting because scientists thought it would be rich in sulfur like other soil exposures they've investigated. Instead, it turned out to be low in sulfur and ultramafic in composition -- made of iron- and magnesium-rich silicate, a chemistry often associated with volcanic rocks. Everett appears to be different from other materials the rover has encountered around "Home Plate."
On sol 1175 (April 23, 2007), Spirit bumped back approximately 60 centimeters (24 inches) to position the robotic arm for analysis of some light-toned nodules called "Slide." Scientists were hoping Slide would be high in silica, but after the investigation discovered that it looked like a still cleaner version of "Everett." The rover is now working on a scientific analysis of a new target known as "Good Question."
Spirit surveyed rocks known as "Charlene Barnett," "Fern Battaglia," and "Joyce Ricketts" as well as an area above a landslide on "Husband Hill" known as "Headscarp" and a vesicular basalt known as "Dorothy Wind."
Spirit completed work on a big-picture mosaic of the Home Plate area called the "Ballpark Panorama."
Sol-by-sol summary:
In addition to daily observations of atmospheric dust levels and surveys of the sky and ground using the miniature thermal emission spectrometer, Spirit conducted the following activities:
Sol 1172 (April 20, 2007): Spirit acquired microscopic images of Everett, acquired columns 8 and 9 of the Ballpark Panorama with the panoramic camera, surveyed Charlene Barnett with the miniature thermal emission spectrometer, and studied Everett with the alpha particle X-ray spectrometer.
Sol 1173: Spirit studied Everett using the Mössbauer spectrometer and acquired columns 10 and 11 of the Ballpark Panorama.
Sol 1174: In the morning, Spirit searched for clouds using the navigation camera. The rover then resumed Mössbauer analysis of Everett, acquired column 12 of the Ballpark Panorama, and surveyed Fern Battaglia with the miniature thermal emission spectrometer.
Sol 1175: Spirit took panoramic images of the sky and crushed surface nodules and acquired movies in search of dust devils using the navigation camera. Spirit then stowed the robotic arm, rolled backward slightly to be able to reach Slide, acquired post-drive images with the navigation camera, and acquired panoramic camera images of the drive ahead.
Sol 1176: Spirit acquired movies in search of dust devils using the navigation camera, acquired panoramic camera images of the sky, stowed the robotic arm, acquired microscopic images of Slide, brushed the surface of Slide with the rock abrasion tool, and acquired microscopic images of the newly brushed surface. The rover studied Slide with the alpha-particle X-ray spectrometer and surveyed Dorothy Wind using the miniature thermal emission spectrometer.
Sol 1177: Spirit acquired panoramic camera images of Everett, searched for dust devils, and studied Slide with the Mössbauer spectrometer.
Sol 1178 (April 27, 2007): In the morning, Spirit acquired panoramic camera images of the "El Dorado" dune field, a landslide area on "Husband Hill" known as "Landslide," and the horizon. The rover continued to study Slide using the Mössbauer spectrometer, acquired panoramic camera images of Dorothy Wind, and acquired data from Joyce Ricketts using the miniature thermal emission spectrometer. The rover prepared to acquire microscopic images and alpha-particle X-ray spectrometer data from Good Question the following morning.
Odometry:
As of sol 1177 (April 26, 2007), Spirit's total odometry was 7,095 meters (4.4 miles).
sol 1164-1171, April 23, 2007: Spirit Continues Studies of Rocks Near 'Home Plate'
After a few attempts, Spirit finally made it to the outcrop called "Madeline English," where the rover is performing scientific studies. Madeline English is interesting because of the apparent presence of clasts -- rock fragments -- in the outcrop. Scientists are interested in determining whether the clasts have a different composition from surrounding material. If it is different, it would be one factor supporting the hypothesis that Madeline English is one of the lowest stratigraphic layers in the region.
Spirit also performed a remote sensing campaign on rocks nicknamed "Elise Harney," "Carol Habben," "Senaida Wirth," "Charlene Barnett," "Alice Haylett," and "Clara Zaph." These and other rock targets are currently being named after deceased members of the All-American Girls Profession Baseball League.
Another rock known as "Elizabeth Mahon" is interesting because it has the highest silica level of any rock analyzed on Mars. Processes that elevate the silica content in a rock generally involve liquid water.
Spirit also began began acquiring a large mosaic, known as the "Ballpark Panorama," of images of the "Home Plate" area using the panoramic camera.
Sol-by-sol summary:
In addition to daily observations of atmospheric dust levels and surveys of the sky and ground with the miniature thermal emission spectrometer, Spirit conducted the following activities:
Sol 1164 (April 12, 2007): Spirit made a second attempt to bump into position next to Madeline English and acquired end-of-drive nagivation camera images.
Sol 1165: Spirit started the day by acquiring panoramic camera images of Carol Habben, then acquired panoramic camera images of Elise Harney.
Sol 1166: Spirit watched for dust devils in the morning and then attempted for a third time to bump into position next to Madeline English. The rover acquired end-of-drive images using the navigation camera.
Sol 1167: Spirit acquired early morning images of Elise Harney with the panoramic camera, then acquired panoramic camera images of Carol Habben. The rover surveyed Senaida Wirth, Charlene Barnett, and Alice Haylett with the miniature thermal emission spectrometer.
Sol 1168: Spirit searched for dust devils in the morning, then unstowed the robotic arm and acquired microscopic images of a particular exposure of Madeline English known as "Belles." The rover surveyed Clara Zaph with the miniature thermal emission spectrometer and studied Belles using the alpha particle X-ray spectrometer.
Sol 1169: Spirit scanned the sky for clouds using the navigation camera and acquired data from Belles using the Mössbauer spectrometer. The rover acquired panoramic camera images of Home Plate.
Sol 1170: Spirit acquired panoramic images of the sky and watched for dust devils. Spirit then restarted the Mössbauer spectrometer for continued analysis of Belles before beginning work on the Ballpark Panorama.
Sol 1171 (April 19, 2007): Spirit scanned the sky for clouds using the navigation camera and acquired microscopic images of rock targets known as "Peaches" and "BlueSox" in addition to Madeline English, along with a light-colored soil target known as "Everett." The rover continued work on the Ballpark Panorama and prepared to start work the following day on a survey of white material in the rover's tracks using the miniature thermal emission spectrometer.
Odometry:
As of sol 1169 (April 17, 2007), Spirit's total odometry was 7,093 meters (4.4 miles).
sol 1159-1163, April 13, 2007: Spirit Continues Studies En Route to 'Home Plate'
Spirit is healthy and has completed a campaign of scientific studies of a rock outcrop known as "Elizabeth Mahon," on the edge of "Home Plate." Spirit is now en route to another outcrop nicknamed "Madeline English." The route involves driving backward, turning around, backing up, parking in parallel between two sizable rocks flanking the target, pivoting clockwise on the stuck right front wheel, and finally "crabbing" forward to the target. Spirit performs crabbing by steering the two rear wheels toward the stuck right front wheel, thus opposing resistance from the right front wheel and keeping yawing (swinging from side to side) to a minimum.
Spirit executed the "parallel parking" portion of the trip on the rover's 1,162nd Martian day, or sol, of exploration (April 10, 2007). The final "crab" portion was planned for sol 1164 (April 12, 2007). After the investigation of Madeline English, plans called for the rover to head north to one of several possible "on-ramps" for driving onto Home Plate.
Sol-by-sol summary:
In addition to daily observations of atmospheric dust levels and surveys of the sky and ground with the miniature thermal emission spectrometer, Spirit conducted the following activities:
Sol 1159 (April 7, 2007): Spirit acquired data from Elizabeth Mahon using the Mössbauer spectrometer, acquired panoramic camera images of a target known as "Tars Tarkas," and studied a rock known as "Johanna Hargraves" using the miniature thermal emission spectrometer.
Sol 1160: Spirit acquired full-color images using all 13 filters of the panoramic camera of Elizabeth Mahon before driving south and taking a mosaic of navigation camera images.
Sol 1161: Spirit acquired a survey of rock clasts using the panoramic camera, a survey at high sun with the panoramic camera, data using the Mössbauer spectrometer from a target known as "Muriel Coben" and a rock called "Elise Harney," and data on atmospheric density of argon gas using the alpha-particle X-ray spectrometer.
Sol 1162: Spirit drove north toward Madeline English and acquired a mosaic of navigation camera images.
Sol 1163: Spirit watched for dust devils using the WATCH computer program, acquired full-color images of Madeline English using all 13 filters of the panoramic camera, studied a rock exposure known as "Phyllis Wise 2" using the miniature thermal emission spectrometer, and acquired full-color panoramic camera images of the rock known as "Phyllis Wise."
Odometry:
As of sol 1162 (April 10, 2007), Spirit's total odometry was 7,092.29 meters (4.41 miles).
sol 1152-1158, April 10, 2007: Spirit Studies Rocks En Route to "Home Plate"
Spirit is healthy and performing scientific studies of an outcrop of light-toned clasts and cobbles nicknamed "Elizabeth Mahon" on the edge of "Home Plate" as well as a pockmarked rock outcrop nicknamed "Madeline English."
To get around obstacles and make progress over rough terrain using only five wheels, Spirit drove backward a few meters, pivoted around the front wheel, drove backward another few meters, pivoted again to face Madeline English, and finally pushed forward to reach the rock with scientific instruments on the robotic arm.
After investigating Madeline English, the rover will head back north to one of several possible "on-ramps" for driving onto Home Plate.
Sol-by-sol summary:
In addition to daily observations of atmospheric dust levels and surveys of the sky and ground with the miniature thermal emission spectrometer, Spirit conducted the following activities:
Sol 1152 (March 31, 2007): Spirit acquired panoramic camera images of a rock exposure known as "Clara Zaph" in addition to miniature thermal emission spectrometer data from "Clara Zaph 1," "Clara Zaph 2," and "Clara Zaph 3." The rover surveyed the sky and ground and targets known as "Rita Briggs" and "Twila Shively" using the miniature thermal emission spectrometer and completed a survey with the sun low in the sky using the panoramic camera.
Sol 1153: Spirit turned southeast and drove backward 4 meters over the target Elizabeth Mahon to place it within the work volume of the rover's scientific instruments. Spirit acquired post-drive images using the navigation camera and relayed data to the Odyssey orbiter overnight.
Sol 1154: Spirit acquired thumbnail images of the sky using the panoramic camera and measured argon using the alpha-particle X-ray spectrometer.
Sol 1155: Spirit unstowed the robotic arm, placed the Mössbauer spectrometer on Elizabeth Mahon, and acquired data overnight. The rover acquired a mosaic of panoramic camera images facing the drive direction and relayed data to Odyssey overnight.
Sol 1156: Spirit continued to acquire overnight data from Elizabeth Mahon using the Mössbauer spectrometer. Spirit acquired full-color images using all 13 filters of the panoramic camera of a target known as "Madeline English 2." The rover acquired miniature thermal emission spectrometer data from Madeline English 2 and targets known as "Betty Hill" and "Madeline English 3."
Sol 1157: Spirit changed tools from the Mössbauer spectrometer to the microscopic imager and acquired a mosaic of microscopic images of Elizabeth Mahon. The rover placed the alpha-particle X-ray spectrometer on the target and collected data overnight while also relaying relayed data to the Odyssey orbiter. Spirit scanned the sky for clouds using the navigation camera and acquired full-color images of white soil using all 13 filters of the panoramic camera.
Sol 1158 (April 6, 2007): Plans called for Spirit to acquire overnight data using the Mössbauer spectrometer, panoramic camera images of Madeline English, and miniature thermal emission spectrometer data on targets known as "Noreen Arnold," "Carol Habben," and "Phyllis Wise."
Odometry:
As of sol 1153 (April 1, 2007), Spirit's total odometry was 7,077.10 meters (4.40 miles).
sol 1145-1151, April 03, 2007: Spirit Begins to Look for Best Access to 'Home Plate'
Spirit is healthy and has finished her science campaign at "Mitcheltree Ridge." The rover is now heading south along the outside edge of "Home Plate" toward an outcrop named "Madeline English." After the investigation of Madeline English the rover will head back north to one of several possible "on-ramps" for making its way onto Home Plate. In the early morning of sol 1151 Spirit will perform its first overnight communications relay with Mars Odyssey since before winter (sol 846)!
Sol-by-sol summary:
In addition to specific daily activities, Spirit's conducted routine atmospheric observations, which include: panoramic camera tau measurements, miniature thermal emission spectrometer sky and ground stares, and panoramic camera sky spots.
Sol 1145 (March 24, 2007): On this sol, the rover continued Mössbauer spectrometer observations on targets "Torquas 2," and completed Mini-TES stares on "Throxus," "Arbok," "Malagor," "Glorestra," "Syl" and "Polodona." Spirit also began a panoramic camera image of Mitcheltree Ridge (North).
Sol 1146: Spirit took a microscopic stereo image of target "John Carter" and completed miniature thermal emission spectrometer stares on targets "Forandus," "Iss" and "Thavas." The rover took an alpha particle X-ray spectrometer reading on John Carter and continued its panoramic camera image of Mitcheltree Ridge (North).
Sol 1147: Spirit captured a navigation camera dust devil sequence and continued on dust devil watch. The rover also began a panoramic camera 13-Filter of Mitcheltree Ridge. The miniature thermal emission spectrometer was used to stare at targets "Darseen" and "Faget." The rover also conducted some panoramic camera photometry experiments.
Sol 1148: The rover stowed its instrument deployment device ("arm"), drove towards Home Plate and then conducted post-drive navigation and panoramic camera imaging. The panoramic camera captured sky thumbnails and the navigation camera shot another dust devil sequence.
Sol 1149: On this sol, the panoramic camera conducted a high sun survey. The rover also took a miniature thermal emission spectrometer 5-point sky & ground stare and a navigation camera dust devil sequence.
Sol 1150: Spirit used its panoramic camera to image nearby outcrop, then drove 8 meters (26 feet) south-southeast toward Madeline English. After the drive, the navigation camera and the panoramic cameras took images.
Sol 1151: Overnight, there was an Odyssey data relay. The panoramic camera conducted a clast survey (looking at rock fragments) and then monitored for dust.
Odometry:
As of sol 1150, Spirit's total odometry was 7,066 meters (4.39 miles).
sol 1141-1144, March 23, 2007: Spirit Studies Rocks in Vicinity of "Home Plate"
Spirit remains healthy and spent much of the week studying a new rock target on "Mitcheltree Ridge" called "Torquas." Scientists are trying to understand what relationship Mitcheltree Ridge has to "Home Plate" -- for example, whether it is an extension of Home Plate or an entirely different rock layer, and whether it has similar composition or morphology.
Torquas is nicknamed after a dried-up seabed covered with moss in the Barsoom science fiction saga by Edgar Rice Burroughs.
Sol-by-sol summary:
In addition to daily observations of atmospheric dust levels and surveys of the sky and ground with the miniature thermal emission spectrometer, Spirit conducted the following activities:
Sol 1141 (March 20, 2007): Spirit acquired panoramic camera images of Torquas, nudged closer to the outcrop, took post-drive images with the navigation camera, acquired images of the sky with the panoramic camera, and watched for dust devils.
Sol 1142: This was a runout sol, or Martian day, meaning the rover completed pre-loaded activities resulting from an only partially successful uplink of new instructions. The uplink was only partially successful because the rover's best-lock frequency was out of range. Runout activities included monitoring atmospheric dust, measuring light looking east and west, imaging the calibration target, and taking thumbnail images of the sky.
Sol 1143: Spirit acquired a 360-degree panorama of images with the navigation camera, stereo microscopic images of Torquas prior to brushing the surface with the rock abrasion tool, and more stereo images after brushing the rock. The rover placed the alpha-particle X-ray spectrometer on the rock and then collected data using the instrument.
Sol 1144 (March 23, 2007): Spirit's first planned task was to acquire panoramic images of Mitcheltree Ridge. Other planned activities included studies of Torquas using the Mössbauer spectrometer, surveys of layered outcrops known as "Zanor," "Banth," "Okar," and "Dor" using the miniature thermal emission spectrometer, and photometric measurements using the panoramic camera.
Odometry:
As of sol 1142 (March 21, 2007), Spirit's total odometry was 7,046 meters (4.38 miles).
sol 1132-1140, March 20, 2007: Spirit Loses, Re-Establishes Contact with Orbiter
Spirit is healthy but had to sit out a Martian day waiting to send data to Earth while the Mars Reconnaissance Orbiter was in safe mode. Both the rover and the orbiter share the same X-band frequency with Earth and must coordinate communications. Ultimately, Spirit sent data to Earth while the Mars Reconnaissance Orbiter was on the other side of Mars, out of reach of Earth.
Spirit drove 21.26 meters (69.75 feet) on the rover's 1,132nd and 1,136th sols, or Martian days, of exploration (March 10 and March 14, 2007), en route to rock targets on "Mitcheltree Ridge."
Sol-by-sol summary:
Sol 1132 (March 10, 2007): Spirit touched a soil target with the Mössbauer spectrometer, acquired microscopic images, and surveyed the sky and ground as well as a vesicular basalt known as "Faye Dancer" using the miniature thermal emission spectrometer. The rover drove 10.2 meters (33.5 feet), took images with the hazard avoidance and panoramic cameras, and acquired a 360-degree mosaic with the navigation camera.
Sol 1133: Spirit began the day by imaging the sky with the panoramic camera. The rover then pointed the navigation camera at the surrounding terrain and acquired a movie in search of dust devils. Spirit surveyed the sky and ground with the miniature thermal emission spectrometer and monitored dust on the rover mast.
Sol 1134: Spirit searched for dust devils in the morning and spent much of the day engaged in remote targeted sensing. Spirit acquired full-color images of a knob known as "Pitchers Mound" using all 13 filters of the panoramic camera. The rover acquired images of an outcrop known as "Backstop" and conducted a survey of rock clasts using the panoramic camera. Spirit acquired data on targets known as "Shirley Jameson," "Connie Wisniewski," "Margaret Stephani," and "Tjanath" using the miniature thermal emission spectrometer. The rover monitored atmospheric dust using the panoramic camera and surveyed the sky and ground as well as targets known as "Phundahl" and "Panar" using the miniature thermal emission spectrometer.
Sol 1135: Spirit began the day by examining scattered light and searching for dust devils with the navigation camera. The rover surveyed targets known as "Ptarth" and "Thark," a large slab of rock called "Torquas," and the sky and ground with the miniature thermal emission spectrometer.
Sol 1136: Spirit's first task of the day was surveying the rover's calibration target and a target known as "Toonal" using the miniature thermal emission spectrometer. Spirit then drove 11.06 meters (36.29 feet) toward an outlying outcrop associated with "Home Plate" (called "outlier 2") and acquired post-drive images using the hazard avoidance and navigation cameras. The rover surveyed the sky and ground using the miniature thermal emission spectrometer.
Sol 1137: In the morning, Spirit acquired thumbnail images of the sky using the panoramic camera and acquired a movie in search of dust devils using the navigation camera. When Spirit did not receive the next day's instructions as a result of being unable to establish a link with Earth while the Mars Reconnaissance Orbiter was in safe mode, the rover instead executed "runout" science activities for the first time in 321 sols. The pre-loaded runout activities included monitoring atmospheric dust, measuring light looking east and west, imaging the calibration target, and taking thumbnail images of the sky.
Sol 1138 (March 9, 2007): Spirit acquired full-color images of targets known as "Ompt" and "Shador" using all 13 filters of the panoramic camera. The rover studied Ompt, Shador, and additional targets known as "Zor" and "Zodanga" using the miniature thermal emission spectrometer. Spirit monitored atmospheric dust using the panoramic camera and conducted an argon experiment using the alpha-particle X-ray spectrometer.
Sol 1139: Spirit's first activities of the day included acquiring full-color images of Zodanga and Zor using all 13 filters of the panoramic camera and searching for clouds using the navigation camera. Spirit acquired hazard avoidance camera images and navigation camera images of potential scientific targets as well as a 360-degree view of the rover's surroundings using the navigation camera. Spirit monitored atmospheric dust using the panoramic camera.
Sol 1140 (March 19, 2007): Spirit took snapshots of the sky using the panoramic camera and acquired a dust devil movie using the navigation camera. The rover measured atmospheric dust, scanned the sky and ground using the miniature thermal emission spectrometer, and looked for clouds using the navigation camera.
Odometry:
As of sol 1136 (March 14, 2007), Spirit's total odometry was 7,033.61 meters (4.37 miles).
sol 1125-1131, March 12, 2007: Spirit Studies "Home Plate" from the West
Spirit is healthy after wrapping up a week of remote sensing observations on the west side of the elevated circular plateau known as "Home Plate."
Sol-by-sol summary:
Sol 1125 (March 3, 2007): Spirit took images of darkness, when the panoramic camera is exposed to no light, for calibration purposes. Spirit acquired microscopic images of the dust capture and filter magnets and surveyed several targets known as "Lothar," "Manator," "Morbus," "Ombra," "Otz Valley," and "Pankor" using the miniature thermal emission spectrometer. The rover monitored atmospheric dust levels with the panoramic camera, surveyed the sky and ground with the miniature thermal emission spectrometer, and searched for clouds using the navigation camera.
Sol 1126: Spirit's first task of the day was acquiring panoramic camera images of the dune field known as "El Dorado." The rover then drove 3.5 meters toward "Home Plate," acquired images using the front and rear hazard avoidance cameras and navigation camera, and monitored atmospheric dust with the panoramic camera. The rover scanned the sky and ground with the miniature thermal emission spectrometer.
Sol 1127: The first thing in the morning, Spirit scanned the sky for clouds using the navigation camera. The rover surveyed the sky at high sun using the panoramic camera. Spirit scanned the sky and ground with the miniature thermal emission spectrometer.
Sol 1128: Spirit started the day by looking for Martian dust devils with the navigation camera. The rover re-acquired images with the front hazard avoidance camera and tested the switch on the contact plate of the Mössbauer spectrometer by touching the filter magnet with the instrument. Spirit acquired navigation camera images and a panoramic camera mosaic of Home Plate. Spirit acquired remote sensing data from targets known as "Irene Hickson," "Joanne Winter," "Bette Trezza," and "Carolyn Morris." The rover surveyed the sky and ground with the miniature thermal emission spectrometer and measured atmospheric dust levels with the panoramic camera.
Sol 1129: Spirit started the day by looking for morning clouds. The rover conducted a survey using the panoramic camera at high sun. Spirit scanned the sky and ground with the miniature thermal emission spectrometer and used the same instrument to acquire remote sensing data from targets known as "Anna Mae Hutchison," "Faye Dancer," "Dorothy Hunter," and "Velma Abbott."
Sol 1130: Spirit searched for morning clouds with the navigation camera and acquired images, using all 13 filters of the panoramic camera, of Home Plate. The rover also acquired data from targets known as "Fredda Acker" and "Jean Gilchrist" with the miniature thermal emission spectrometer. The rover took calibration images of darkness and monitored atmospheric dust with the panoramic camera. Spirit acquired data from a target known as "Betty Warfel" using the miniature thermal emission spectrometer.
Sol 1131 (March 9, 2007): Spirit took images of the sky with the panoramic camera and surveyed the sky and ground with the miniature thermal emission spectrometer. The rover acquired miniature thermal emission spectrometer data and panoramic camera images of a target known as "Evelyn Adams." Spirit took full-color images, using all 13 filters of the panoramic camera, of a target called "Joanne Winter." The rover acquired miniature thermal emission spectrometer data from targets known as "Bethany Goldsmith," "Betty Whiting," and "Melba Alspaugh." Spirit took panoramic camera images and prepared to spend the next morning acquiring two movies in search of dust devils using the panoramic camera.
Odometry:
As of sol 1130 (March 8, 2007), Spirit's total odometry was 7,012.34 meters (4.36 miles).
sol 1118-1124, March 08, 2007: Spirit Studies Rock Outcrops, Drives Near 'Home Plate'
Spirit is healthy and making progress on the return trip to "Home Plate." The rover headed north along Home Plate to fill in gaps in imagery left behind when Spirit rushed to find a winter haven.
Use of the rover's robotic arm remains on hold until more diagnostics can be performed.
Sol-by-sol summary:
In addition to daily observations that included measuring atmospheric opacity caused by dust with the panoramic camera, scanning the sky for clouds with the navigation camera, surveying the sky and ground with the miniature thermal emission spectrometer, and taking reference images of the sky, Spirit conducted the following activities:
Sol 1118 (Feb. 24, 2007): Spirit took panoramic camera images of rock outcrops "Dorothy Kamenshek" and "Olive Little" as well as Home Plate. The rover surveyed Olive Little and targets known as "Kamtol" and "Korvas" with the miniature thermal emission spectrometer.
Sol 1119: Spirit drove 7.94 meters (26.1 feet) toward Home Plate, took navigation camera images after the drive, acquired navigation camera movies in search of dust devils, and monitored atmospheric dust.
Sol 1120: Spirit searched for clouds using the WATCH computer sequence.
Sol 1121: Spirit acquired panoramic camera images of Home Plate, drove 14.24 meters (46.72) feet, acquired post-drive navigation camera images, surveyed the horizon with the panoramic camera, and searched for clouds using the WATCH computer sequence.
Sol 1122: Spirit measured atmospheric argon using the alpha particle X-ray spectrometer and monitored atmospheric dust.
Sol 1123: Spirit acquired panoramic camera images of Home Plate, surveyed a target known as "Madeline English" with the miniature thermal emission spectrometer, drove 7.95 meters (26.1 feet) toward Home Plate, and acquired post-drive images, including looking toward the rear, with the navigation camera.
Sol 1124 (March 2, 2007): Spirit completed a survey of rock clasts using the panoramic camera.
Odometry:
As of sol 1123 (March 1, 2007), Spirit's total odometry was 7007.84 meters (4.35 miles).
sol 1113-1117, February 23, 2007: Spirit Continues Driving While Engineers Check Robotic Arm
Spirit is healthy and making progress on the return trek to "Home Plate." Rover handlers have put use of the robotic arm on hold in order to run diagnostic tests of apparent positioning errors in the placement of instruments on the arm. Meanwhile, Spirit continues driving, searching for dust devils and clouds using WATCH computer commands, and acquiring other remote sensing data.
Sol-by-sol summary
In addition to daily observations that included measuring atmospheric opacity caused by dust with the panoramic camera, scanning the sky for clouds with the navigation camera, surveying the sky and ground with the miniature thermal emission spectrometer, and taking reference images of the sky, Spirit conducted the following activities:
Sol 1113 (Feb. 19, 2007): Spirit acquired full-color images, using all 13 filters of the panoramic camera, of a knobby rock known as "Fabien" and targets known as "Kadabra" and "Kaol."
Sol 1114: Spirit rolled slightly backward, turned, and drove 8.61 meters (28.3 feet) toward Home Plate. Spirit searched for dust devils using the WATCH commands.
Sol 1115: Spirit acquired movie frames in search of dust devils and searched for clouds using the WATCH commands.
Sol 1116: Spirit drove 8 meters (26 feet), acquired westward-looking and northward-looking images after the drive, and acquired thermal data from a soil target known as "Kabal" using the miniature thermal emission spectrometer.
Sol 1117 (Feb. 23, 2007): Spirit acquired full-color images of the area in front of the rover using all 13 filters of the panoramic camera.
Odometry
As of sol 1114 (Feb. 20, 2007), Spirit's total odometry was 6,969.03 meters (4.33 miles).
sol 1104-1112, February 16, 2007: Spirit Perfects the Art of Driving on Five Wheels
Rover drivers have now refined their techniques for maneuvering on only five wheels. All of Spirit's drives during the past week ended within centimeters (inches) of the targeted endpoint. Spirit is healthy and has arrived at the rock outcrop known as "Bellingshausen" on the way back to "Home Plate."
On Feb. 10, 2007, the rover's 1,104th Martian day, or sol, of exploration, Spirit experienced a warm reset, during which the rover's computer rebooted and the rover went into auto mode, canceling activities for the weekend and awaiting instructions from Earth. This is the third time Spirit has experienced this anomaly; Spirit's twin, Opportunity, has experienced it twice. The anomaly is attributed to a well-known condition in the flight software. The rover's handlers sent new commands that activated the master sequence of activities for sol 1107 (Feb. 13, 2007).
During scientific studies of targets known as "Mount Darwin" and "Puenta Arenas" in soil disturbed by the rover's tracks, Spirit's handlers noticed positioning errors in the placement of instruments on the rover's robotic arm. In response, they scheduled diagnostic tests for sol 1110 (Feb. 16, 2007). This left the team with a tough decision: remain at Bellingshausen during the long President's Day holiday weekend or head toward Home Plate with a day of driving on sol 1114 (Feb. 20, 2007).
Tau measurements of atmospheric dust levels were 0.6, while solar power levels were 312 watt-hours (100 watt-hours is the amount of electrical energy needed to light a 100-watt bulb for one hour).
Sol-by-sol summary:
Except for the sols spent in auto mode, Spirit made daily observations that included measuring atmospheric opacity caused by dust with the panoramic camera, scanning the sky for clouds with the navigation camera, and surveying the sky and ground with the miniature thermal emission spectrometer. Spirit also conducted the following activities:
Sol 1104 (Feb. 10, 2007): Spirit went into auto mode.
Sol 1105: Spirit remained in auto mode.
Sol 1106: Spirit remained in auto mode.
Sol 1107: Spirit drove to the Bellingshausen outcrop.
Sol 1108: Spirit acquired panoramic camera images of Bellingshausen and navigation camera movie frames in search of clouds.
Sol 1109: Spirit turned and approached a rock target known as "Fabian" and acquired stereo images following the drive using the navigation camera. The rover also acquired images with the panoramic camera.
Sol 1110: Plans called for a "rover tai-chi," which involves taking images of the contact ring of the Mössbauer spectrometer with the front hazard avoidance camera before placing the instrument on a target, and for acquiring panoramic camera images of Bellingshausen.
Sol 1111: Planned activities included collecting data on targets known as "Amhor," "Bantoom," "Dusor," "Ghasta," and "Gooli" with the miniature thermal emission spectrometer.
Sol 1112 (Feb. 18, 2007): Planned activities included collecting data on targets known as "Horz," "Hastor," and "Invak" with the miniature thermal emission spectrometer.
Odometry:
As of sol 1109 (Feb. 15, 2007), Spirit's total odometry was 6,965 meters (4.3 miles).
sol 1097-1103, February 09, 2007: It's Officially Spring on Mars
Spring is in the thin, Martian atmosphere once again as NASA's Mars Exploration Rover Spirit scans the local terrain for dust devils expected this time of year. The rover remains healthy and has completed remote sensing studies of a soil target known as "Tyrone," conducted from a distance of about 10 meters (33 feet) away. Tyrone has bright soil upturned in wheel tracks.
Because Spirit is now limited to driving on five wheels, Spirit's handlers did not feel comfortable sending the rover any closer to the soft soil surrounding Tyrone. On the rover's 1,102nd Martian day, or sol, of exploration (Feb. 7, 2007), the rover turned and retraced its tracks toward the layered rock exposure known as "Montalva" en route to the circular plateau known as "Home Plate."
Engineers planned to have Spirit drive approximately 8 meters (26 feet) early on sol 1103 (Feb. 8, 2007). Planned weekend activities included remote sensing observations in addition to the long drive back to Home Plate. Estimated dust levels, known as Tau measurements, appeared to be holding steady at around 0.55. Scientists are hopeful that Martian winds will clear dust from Spirit's solar panels and boost the rover's power levels as they did at around this time last year.
Sol-by-sol summary:
In addition to daily observations that included using the panoramic camera to measure atmospheric opacity, using the navigation camera to scan the sky for clouds, and using the miniature thermal emission spectrometer to survey the sky and ground, Spirit completed the following activities:
Sol 1097 (Feb. 2, 2007): Spirit used the miniature thermal emission spectrometer to acquire data on Tyrone and a rock target known as "Korolev." Spirit placed the alpha-particle X-ray spectrometer on an exposure of white soil known as "Mount Darwin" and collected compositional data. Spirit also acquired images of Tyrone using the panoramic camera.
Sol 1098: Spirit continued to gather miniature thermal emission spectrometer data from Tyrone and alpha-particle X-ray spectrometer data from Mount Darwin.
Sol 1099: Spirit acquired microscopic images of Mount Darwin, scanned a target known as "Russkaya" with the miniature thermal emission spectrometer, and acquired more panoramic camera images of Tyrone.
Sol 1100: Spirit studied Mount Darwin with the Mössbauer spectrometer, continued to acquire data from Tyrone using the miniature thermal emission spectrometer, and acquired panoramic camera images of a sinuous feature in the dirt called "Hermite" and of the distant "El Dorado" dune field.
Sol 1101: Spirit acquired microscopic images of "Punta Arenas," a pebble in one of the rover's tracks. The panoramic camera photographed Tyrone. The miniature thermal emission spectrometer scanned distant "McCool Hill." Spirit also used the panoramic camera for images of Mount Darwin and Puenta Arenas.
Sol 1102: Spirit acquired images of McCool Hill with the panoramic camera. Then it turned to drive back toward Home Plate and updated the rover's knowledge of its position relative to the sun.
Sol 1103 (Feb. 8, 2007): Plans called for Spirit to take images of "Tyrone Vista" (the rover's view of the upturned soil known as Tyrone along with the surrounding terrain) and drive toward Montalva.
Odometry:
As of sol 1102 (Feb. 7, 2007), Spirit's total odometry was 6,926.42 meters (4.3 miles).
sol 1091-1096, February 01, 2007: Spirit Examines Churned-Up Martian Soil
Spirit is healthy and continues to scan the Martian terrain for the dust devils of spring. The rover has completed its scientific studies of a layered rock exposure known as "Montalva" on an outcrop called "Troll."
The rover is now en route toward a patch of bright soil churned up by the rover's wheels in March 2007. Known as "Tyrone," the patch of bright material, white and yellow in color, is possibly analogous to salty soils discovered by the rover earlier in the mission. Scientists plan to have the rover conduct remote sensing from a distance of about 10 meters (33 feet) in order to avoid getting mired in the sand. The rover will use its scientific instruments to get a better look at the soil exposure and determine whether it contains sulfates.
Spirit acquired movies with the navigation camera in search of dust devils on the rover's 1091st, 1093rd, and 1095th sols, or Martian days (Jan. 27, Jan. 29, and Jan. 31, 2007). The risk of dust storms is predicted to increase through mid-October 2007.
The rover drove 12 meters (39 feet) between sols 1092 (Jan. 28, 2007) and 1094 (Jan. 30, 2007).
Sol-by-sol summary:
In addition to daily observations that included measuring atmospheric dust with the panoramic camera and surveying the sky and ground with the miniature thermal emission spectrometer, Spirit completed the following activities:
Sol 1091 (Jan. 27, 2006): Spirit acquired panoramic camera images of a rock target known as "Zucchelli" as well as images for building a digital elevation model of the terrain between the rover and a rock of vesicular basalt known as "Esperanza." Spirit acquired movie frames with the navigation camera in search of dust devils and used the miniature thermal emission spectrometer to acquire data on rock targets known as "Troll 1," "Macquarie," and "Troll 2."
Sol 1092: Spirit acquired navigation camera images following the day's drive and panoramic camera images of the sky for calibration purposes.
Sol 1093: Spirit acquired movie frames with the navigation camera in search of dust devils and navigation camera images in support of observations to be made with the miniature thermal emission spectrometer. Spirit scanned the foreground with the miniature thermal emission spectrometer, monitored for dust on the rover mast with the panoramic camera, and conducted a survey of rock clasts with the panoramic camera.
Sol 1094: Spirit acquired panoramic camera images of a rock target called "Druzhnaya," drove closer to Tyrone, and acquired post-drive images of the rover's surroundings using the navigation camera.
Sol 1095: Spirit acquired data on Tyrone using the miniature thermal emission spectrometer, acquired movie frames with the navigation camera in search of dust devils, acquired data on a rock outcrop known as "Oberth," and acquired full-color images of Tyrone using all 13 filters of the panoramic camera.
Sol 1096 (Feb. 1, 2007): Spirit "bumped," or rolled a short distance, toward a scientific target to be examined with instruments on the rover arm, acquired post-drive images with the navigation camera, scanned the sky for clouds with the navigation camera, and acquired thumbnail images of the sky with the panoramic camera.
Odometry:
As of sol 1094 (Jan. 30, 2006), Spirit's total odometry was 6,915 meters (4.3 miles).
sol 1085-1090, January 27, 2007: Spirit Studies Layered Rocks and Wind-Blown Drifts
With the rover's third Martian spring just around the corner, Spirit is healthy and has started acquiring movies with the navigation camera in search of dust devils wheeling across the terrain. Spring officially begins on Martian day, or sol 1103 (Feb. 8, 2007).
During the past week, Spirit acquired microscopic images of a soil target called "Londonderry," which is an active wind drift shaped by the motion of bouncing sand grains. Spirit also acquired super-resolution panoramic camera images of an exposure of layered bedrock with rounded rock fragments known as "Zucchelli." Scientists hope the images will reveal information about color, structure, grain size, and mineralogical composition of the rock.
Spirit continued to make progress on scientific studies of a rock exposure known as "Montalva" on the lower stratigraphic unit of an outcrop known as "Troll." On the rover's 1,085th sol (Jan. 21, 2007) of exploration, Spirit used the wire brush on the rock abrasion tool to reveal more surface area and enable clean measurements with the miniature thermal emission spectrometer. Spirit then backed up to conduct analysis of the newly brushed area.
In the coming week, scientists plan to have Spirit retrace its tracks toward a soil exposure known as "Tyrone" for additional panoramic camera images and miniature thermal emission spectrometer measurements to be taken from a distance of about 10 meters (30 feet).
Sol-by-sol summary:
In addition to daily observations that included measuring atmospheric dust with the panoramic camera and surveying the sky and ground with the miniature thermal emission spectrometer, Spirit completed the following activities:
Sol 1085 (Jan. 21, 2006): Spirit acquired stereo microscopic images of Londonderry, as well as a target known as "Contact" and used the wire brush on the rock abrasion tool to brush the surface of Montalva. Spirit acquired panoramic camera images of layered rock targets known as "Los Estados," "Wollaston," and "Monte Dinero."
Sol 1086: Spirit acquired miniature thermal emission spectrometer data on rock targets called "Svea" and "Maudhem." Spirit acquired navigation camera movies in search of dust devils and acquired panoramic camera images of the Martian horizon and sky.
Sol 1087: Spirit stowed the robotic arm and backed up before taking navigation camera images in support of observations to be made with the miniature thermal emission spectrometer. Spirit acquired navigation camera images after backing up and acquired panoramic camera images of the drive direction.
Sol 1088: Spirit acquired panoramic camera images of the rock target now called "Montalva Daisy," in honor of the daisy-like arrangement of circular brushed areas on the rock's surface. The rover acquired data on Montalva Daisy and the background area around the target using the miniature thermal emission spectrometer. The rover surveyed the sky for calibration purposes using the panoramic camera.
Sol 1089: Plans called for Spirit to acquire long-baseline stereo images, using the panoramic camera, of the circular, plateau-like feature known as "Home Plate" in preparation for going back there after having survived the Martian winter. To do this, the rover moves laterally from one point to another between taking images with the left and right eyes of the camera. Plans also called for the rover to take super-resolution panoramic camera images, as well as navigation camera images of the rock target "Zucchelli," and to acquire data on Montalva using the miniature thermal emission spectrometer. The rover was also to acquire post-drive images of the terrain using the navigation camera and take thumbnail images of the sky using the panoramic camera.
Sol 1090 (Jan. 20, 2007): Plans called for Spirit to use the navigation camera to watch for dust devils and take images in support of investigations with the miniature thermal emission spectrometer. The rover was also slated to collect data with the miniature thermal emission spectrometer and complete a survey of rock clasts using the panoramic camera.
Odometry:
As of sol 1087 (Jan. 23, 2006), Spirit's total odometry was 6,896 meters (4.28 miles).
sol 1079-1084, January 19, 2007: Spirit Studies Distinctive Rock Layers with Granules and Platy Beds
Spirit is healthy and continues to make progress on scientific studies of a rock exposure known as "Montalva," which is one of the lower layers of an outcrop known as "Troll." Compositional data that Spirit collected using the alpha-particle X-ray spectrometer suggest the rock has high potassium content. To confirm this, scientists selected an adjacent exposure for further scrutiny.
In addition, Spirit began scientific analysis of an exposure known as "Riquelme" within the middle stratigraphic units of the "Troll" outcrop. Riquelme is composed of spherical particles that may be lapilli, which are pebble- to granule-size rocks ejected during a volcanic eruption. Spirit is also acquiring data about an upper exposure, nicknamed "Zucchelli," of thin platy beds in the outcrop using the panoramic camera and alpha-particle X-ray spectrometer.
During the week, Spirit acquired stereo panoramic camera images of the raised, circular plateau known as "Home Plate" for use in creating a digital elevation model. The navigation camera acquired movie frames in search of dust devils on the rover's 1082nd and 1084th sols, or Martian days of exploration (Jan. 18, 2007 and Jan. 20, 2007).
Science team members plan to have Spirit observe a transit of the Martian moon Phobos as it passes between the rover and the sun on sol 1083 (Jan. 19, 2007) and attempt to acquire panoramic camera images of comet McNaught at sunrise. It is possible that predawn sunlight will make the comet hard to see.
Dust levels have been returning to normal levels, with tau (a measure of how obscured the sun is when viewed through the atmosphere) dropping to 0.549 on sol 1081 and resulting in increased solar energy of 343 watt-hours. After recent dust storm activity on Mars, tau peaked at 1.136 on sol 1066 (Jan. 1, 2007), resulting in solar array energy of 276 watt-hours.
Sol-by-sol summary:
Sol 1079 (Jan. 15, 2006): Spirit placed the alpha-particle X-ray spectrometer on a new, offset target near Montalva, acquired miniature thermal emission spectrometer data on rock targets known as "Guillaume" and "von Neumayer," surveyed the sky and ground using the miniature thermal emission spectrometer, and spent 5 hours collecting data with the alpha-particle X-ray spectrometer.
Sol 1080: The panoramic camera acquired a full-color image of Zucchelli using all 13 filters of the panoramic camera. The microscopic imager inspected "Montalva Offset." The rover swung the robotic arm out of the way to take panoramic camera images of both that target and Riquelme. Spirit acquired microscopic images of Riquelme before placing the alpha-particle X-ray spectrometer on the target. The rover surveyed a rock target known as "Lazarev" using the miniature thermal emission spectrometer.
Sol 1081: Spirit acquired panoramic camera images of Home Plate and the dune field known as "El Dorado." Spirit checked the calibration target and surveyed a target known as "Maud Land" with the miniature thermal emission spectrometer. Spirit acquired data using the alpha-particle X-ray spectrometer, images of the sky using the panoramic camera, and movie frames of potential dust devils using the navigation camera.
Sol 1082: Plans called for Spirit to measure atmospheric dust, survey the sky and ground with the miniature thermal emission spectromter, and acquire data on "Riquelme3" using the Mössbauer spectrometer. Plans also called for Spirit to take images of the sky for calibration purposes using the panoramic and navigation cameras; survey the sky, ground, and a rock outcrop known as "d'Unville" using the miniature thermal emission spectrometer; and take panoramic camera images of the Phobos transit.
Sol 1083: Plans called for Spirit to measure atmospheric dust opacity, acquire navigation camera and panoramic camera images of the sky for calibration purposes, and survey the sky and ground with the miniature thermal emission spectrometer. Plans also called for continued work on Riquelme3, during which Spirit was to acquire additional data about iron composition with the Mössbauer spectrometer. The rover was also to study "Zucchelli3" using the miniature thermal emission spectrometer.
Sol 1084 (Jan. 20, 2007): Plans called for Spirit to measure atmospheric dust, scan the sky and ground with the miniature thermal emission spectrometer, continue Mössbauer analysis of Riquelme3, conduct miniature thermal emission spectrometer analysis of "Zucchelli4," and acquire navigation camera frames in search of dust devils. The next morning's activities were to include panoramic camera images of a soil slip known as "Lennox" and continued miniature thermal emission spectrometer analysis of "Zucchelli5."
Odometry:
As of sol 1081 (Jan. 17, 2006), Spirit's total odometry was 6,895 meters (4.28 miles).
sol 1070-1078, January 12, 2007: Spirit Continues to Test New Computer Smarts
On the rover's 1,068th sol, or Martian day of exploration on Mars (Jan. 4, 2007), Spirit used its new computer smarts to autonomously acquire images of the terrain using the hazard avoidance camera, construct a three-dimensional model of the terrain, identify rock or soil exposures of interest, and generate plans for placing the Mössbauer spectrometer and microscopic imager on 10 of those targets. Spirit's twin, the Opportunity rover on the other side of Mars, completed the same exercise. The next step of the testing process for both rovers will be to actually place scientific instruments on a target of interest.
Spirit spent much of the past week studying a layered rock exposure known as "Montalva." During the study, the rover used the brush on the rock abrasion tool, the microscopic imager, the alpha-particle X-ray spectrometer that collects information about elemental composition, and the Mössbauer spectrometer that identifies iron-bearing minerals.
Plans called for Spirit to observe three transits of the Martian moon Phobos as it passed between the rover and the sun on sols 1075 (Jan. 11, 2007), 1077 (Jan. 13, 2007), and 1078 (Jan. 14, 2007).
Sol-by-sol summary:
Sol 1070 (Jan. 6, 2006): Spirit unstowed the robotic arm and brushed the surface of Montalva, acquired a microscopic image of the rock, and placed the alpha-particle X-ray spectrometer on it for elemental analysis. Before shutting down for the evening, Spirit measured atmospheric dust using the panoramic camera.
Sol 1071: Spirit acquired a full-color image, using all 13 filters of the panoramic camera, of a boulder nicknamed "Davis." It also used the navigation camera for images of scientific targets, and used the miniature thermal emission spectrometer to measure atmospheric dust and to surveyed the sky and ground, while communicating with the Odyssey orbiter in the afternoon.
Sol 1072: Spirit scanned the foreground using the miniature thermal emission spectrometer, acquired 4 hours worth of data using the alpha-particle X-ray spectrometer, monitored atmospheric dust with the panoramic camera, and took images of the sky for calibration purposes.Sol 1073: Spirit swung the robotic arm out of view to collect full-color, 13-filter images of Montalva with the panoramic camera and acquired 4 hours of worth of data using the Mössbauer spectrometer. The rover scanned the sky and ground using the miniature thermal emission spectrometer, monitored dust accumulation on the rover mast, measured atmospheric dust, and imaged the sky for calibration purposes.
Sol 1074: Spirit used the navigation camera and the miniature thermal emission spectrometer observe a nearby rock known as "Kohnen" and another target known as "Amundsen." Spirit fired up the Mössbauer spectrometer for another 3 hours worth of analysis of Montalva. The rover turned off the Mössbauer spectrometer and monitored atmospheric dust.
Sol 1075: Spirit observed the morning transit of Phobos using the miniature thermal emission spectrometer, fired up the Mössbauer for an overnight observation, acquired thumbnail images of the sky using the panoramic camera, and searched for dust devils by acquiring video frames using the navigation camera.
Sol 1076: Plans called for Spirit to use the Mössbauer spectrometer for another 3 hours of study of Montalva and to take images of the sky for calibration purposes with the navigation and panoramic cameras. Spirit was also to monitor atmospheric dust and pre-position the panoramic camera to acquire images of the next day's transit of Phobos.
Sol 1077: Plans called for Spirit to acquire images of the sky for calibration purposes while communicating directly with Earth using the high-gain antenna. Plans also called for Spirit to use the Mössbauer for 12 hours of analysis of Montalva, heat up the electronics inside the panoramic camera, and acquire images of the Phobos transit with the panoramic camera.
Sol 1078 (Jan. 14, 2007): Plans called for Spirit to scan the sky for clouds using the navigation camera, study a target known as "Svarthammaren," and survey the sky and ground during the Phobos transit at 1:45 p.m. local solar time using the miniature thermal emission spectrometer. The rover was to survey targets known as "Sejong" and "Amery" and search the sky for clouds again the following morning using the navigation camera.
Odometry:
As of sol 1075 (Jan. 11, 2006), Spirit's total odometry was 6,895 meters (4.28 miles).
sol 1063-1069, January 05, 2007: Martian Weather Delays Travel Plans
The dust storm season has apparently arrived at Gusev, causing delays in Spirit's fourth Earth year of exploring the Red Planet. Spirit spent most of the holiday season of 2006 and 2007 keeping an eye on the sky, measuring atmospheric dust that could prevent sunlight from reaching the rover's solar panels.
During the past week, atmospheric dust levels have been typical for this time of year on Mars, measuring about 1 on the scale used by the rover. The rover estimates dust levels by measuring opacity -- the degree to which the atmosphere is impenetrable by light. This value is known as tau and varies on a continuous scale from 0 on up. During most of Spirit's mission on Mars, tau values have fallen between 0 and 1. Values between 1 and 2 can greatly limit the activities the rover can perform. Values of 2 or greater could be fatal.
In addition to measuring atmospheric dust, Spirit continued to watch for dust devils and successfully retested step No. 3 of new computer smarts that will enable the rover to autonomously place scientific instruments of the rover's robotic arm onto a target of scientific interest. During the test, Spirit was able to take images of the workspace, unstow the arm, and plan a path of approach for reaching a target.
Next up for Spirit will be an attempt to approach and conduct scientific analysis of a layered rock exposure known as "Montalva," part of a larger outcrop known as "Troll."
Sol-by-sol summary:
In addition to daily observations that included measuring atmospheric dust with the panoramic camera, searching for clouds with the navigation camera, scanning the sky and ground with the miniature thermal emission spectrometer, and imaging the sky with the panoramic camera, Spirit completed the following activities.
Sol 1063 (Dec. 29, 2006): After completing a short drive the previous day to a north-facing slope that tilted the rover's solar panels toward the sun, Spirit monitored atmospheric dust, acquired panoramic camera images of a place (called "Desolacion") where the rover's tracks cross each other, surveyed the Martian horizon with the panoramic camera, and monitored dust accumulation on the rover mast.
Sol 1064: Spirit monitored atmospheric dust and surveyed the sky and ground with the miniature thermal emission spectrometer.
Sol 1065: Spirit monitored atmospheric dust.
Sol 1066: Spirit monitored atmospheric dust.
Sol 1067: Spirit monitored atmospheric dust and searched for dust devils by acquiring successive navigation camera images that could be made into a movie.
Sol 1068 (Third Earth-year anniversary of Spirit's landing): Spirit monitored atmospheric dust, surveyed surrounding rocks with the panoramic camera, acquired full-color images of Desolacion with the panoramic camera, and retested step No. 3 of the robotic arm autonomous placement code.
Sol 1069 (Jan. 5, 2006): Plans called for Spirit to approach Montalva, acquire full-color panoramic camera images of a spongy-looking lava rock known as "Esperanza," and acquire panoramic camera images of Montalva and another layered rock exposure known as "Riquelme."
Odometry:
As of sol 1062 (Dec. 28, 2006), Spirit's total odometry was 6,891.34 meters (4.28 miles)
sol 1058-1062, January 02, 2007: Spirit Rests During Dust Storm
A sudden dust storm cut short Spirit's investigation of a volcanic rock and kicked enough dust into the Martian atmosphere to drive solar power levels to an all-time low. Spirit's team of scientists and engineers decided to move the rover to a spot where the solar panels would be tilted toward the sun to increase the amount of electrical power available.
The southern hemisphere dust storm lowered power levels to 267 watt-hours on Spirit's 1,061st sol, or Martian day, of exploring Mars (Dec. 27, 2006). Spirit had been using its Mössbauer spectrometer to analyze the mineral composition of a rock nicknamed "Esperanza," a piece of lava full of tiny holes and known as vesicular basalt. Due to concern about low power, the team prepared to drive Spirit to a north-tilted spot on the way toward a new target, a layered outcrop known as "Troll."
Spirit spent the New Year's weekend in one place, monitoring dust and actually resting on a holiday.
Sol-by-sol summary:
Sol 1058 (Dec. 24, 2006): Spirit completed 4 hours and 42 minutes of analysis of a target known as "Palma" on the rock Esperanza using the Mössbauer spectrometer. The rover tested Step No. 2 of a software program to watch for dust devils and studied a target known as "Boudouin" with the miniature thermal emission spectrometer.
Sol 1059: Spirit spent an additional 3 hours and 48 minutes collecting information about Palma with the Mössbauer spectrometer, scanned rock outcrops known as "Gurruchaga" and "Oberth" with the miniature thermal emission spectrometer, and acquired super-resolution images of a rock target known as "Molodezhnaya."
Sol 1060: Spirit acquired an additional 4 hours and 47 minutes worth of Mössbauer spectrometer data from Palma and surveyed the Martian horizon with the panoramic camera.
Sol 1061: Spirit completed 3.5 hours of Mössbauer spectrometer analysis of Palma, bringing the total number of hours spent collecting data about the rock to 25. Spirit then acquired data from a rock target known as "Scott_Base" with the miniature thermal emission spectrometer and acquired a full-color image of a soil target known as "Tyrone" using all 13 filters of the panoramic camera.
Sol 1062 (Dec. 28, 2006): The team prepared to send Spirit driving about 4 meters (13 feet) to a shallow slope selected because it would tilt the rover's solar arrays toward the sun, which was still fairly low above the northern horizon and dimmed by atmospheric dust.
Odometry:
On sol 1062 (Dec. 28, 2006), Spirit's total odometry reached 6,891.34 meters (4.28 miles).
sol 1051-1057, December 22, 2006: Spirit Tests New Computer Smarts, Studies Rocks and Terrain
Spirit is healthy and conducting scientific analysis of a rock target known as "Palma." During the past week, Spirit tested some new software sequences, including a "watch for dust devil" command and an automatic placement command.
On the rover's 1052nd Martian day, or sol, of exploring Mars (Dec. 18, 2006), Spirit ran part of the dust devil watch, acquiring six images during the process, but did not run the dust-devil detection part of the program. Rover handlers planned to rerun the test on sol 1058 (Dec. 24, 2006).
On sol 1053 (Dec. 19, 2006), Spirit terminated a test run of a command sequence for autonomous placement of the rover's robotic arm on a scientific target. The sequence involved touching a target with the Mössbauer spectrometer, changing tools to the microscopic imager and suspending it 10 centimeters (4 inches) above the target, changing tools to the alpha-particle X-ray spectrometer, and placing the alpha-particle X-ray spectrometer on the target. Spirit made preparations to run the test again on a new target on the same day that some Earthlings celebrate as Christmas Eve.
Sol-by-sol summary:
Sol 1051 (Dec. 17, 2006): Spirit turned to face a rock outcrop known as "Esperanza," acquired images with the hazard avoidance cameras and a 360-degree panorama with the panoramic camera, and scanned the sky for clouds with the navigation camera. The rover measured atmospheric dust, looked at the sky, examined the terrain, and completed a survey of individual rock grains, known as clasts, using the panoramic camera.
Sol 1052: Spirit conducted step No. 2 of the new capability to watch for dust devils and scanned the sky for clouds with the navigation camera.
Sol 1053: Spirit acquired microscopic images of Palma, conducted step No. 2 of the autonomous placement test, monitored dust in the atmosphere with the panoramic camera, scanned the sky and ground with the miniature thermal emission spectrometer, scanned the sky for clouds with the navigation camera, and monitored the rover mast for dust accumulation.
Sol 1054: Spirit scanned the sky and ground with the miniature thermal emission spectrometer and collected miniature thermal emission spectrometer data from a ground target known as "Melchior." The rover continued to measure atmospheric dust opacity and take images of the sky with the panoramic camera.
Sol 1055 (Dec. 21, 2006): Because the rover was not stationed at the appropriate distance from the target for the automatic placement test, Spirit prepared to run the test with the alpha-particle X-ray spectrometer a second time, followed by six hours of measurement with the instrument. Spirit was slated to scan the sky, ground, and a target known as "Druzhnaya" using the miniature thermal emission spectrometer as well as acquire frames for a dust devil movie.
Sol 1056: Plans called for four hours of analysis of Palma using the Mössbauer spectrometer, measurements of atmospheric dust with the panoramic camera, a check for changes over time in the miniature thermal emission spectrometer, and a scan of the ground and sky at various elevations using the miniature thermal emission spectrometer. Spirit was also to acquire panoramic camera and stereo images of a rock nicknamed "Orcadas."
Sol 1057 (Dec. 23, 2006): Plans called for Spirit to conduct an additional 3.5 hours of study of Palma using the Mössbauer spectrometer, measure atmospheric dust with the panoramic camera, check for drift (changes in time) in the miniature thermal emission spectrometer, scan the sky and ground with the miniature thermal emission spectrometer, check the calibration target of the same instrument, and use it to scan a rock target known as "Gueslaga."
Odometry:
As of sol 1054 (Dec. 20, 2006), Spirit's total odometry was 6,886.80 meters (4.28 miles).
sol 1043-1050, December 18, 2006: Relay Link Restored After Orbiter's Recovery
After Spirit drove on sol 1041 (Dec. 7, 2006), NASA's Mars Odyssey orbiter went into safe mode before the rover's could relay data to Earth about results of the drive. (Safe mode is a protective state during which only the systems essential to spacecraft health continue operating. This incident of Odyssey temporarily going into safe mode has been attributed to a burst of solar activity.) Since the rover team didn't have current information about Spirit's position and state, the rover spent eight successive Martian days, or sols, collecting untargeted remote sensing data.
Data transmission directly to Earth from Spirit on sol 1046 (Dec. 12, 2006) confirmed that Spirit was healthy. Odyssey recovered the following day and resumed relaying data from Spirit, transmitted from the rover to the orbiter in the UHF radio band.
Sol-by-sol summary:
Sol 1043 (Dec. 9, 2006): Spirit surveyed the rover's tracks using the miniature thermal emission spectrometer and measured atmospheric dust opacity with the panoramic camera. The rover surveyed the sky and ground with the miniature thermal emission spectrometer.
Sol 1044: Spirit surveyed the area where the rover spent the past Martian winter with the miniature thermal emission spectrometer and took panoramic camera images of the area.
Sol 1045: Spirit took thumbnail images of the sky with the panoramic camera and scanned the sky for clouds with the navigation camera. Spirit monitored the rover mast for dust and relayed the first bits of scientific data collected and stored on sol 1040 (Dec. 6, 2006).
Sol 1046: Spirit surveyed the rover's winter haven with the miniature thermal emission spectrometer and monitored atmospheric dust with the panoramic camera. The rover scanned the sky and ground with the miniature thermal emission spectrometer.
Sol 1047: Spirit collected miniature thermal emission spectrometer data from a soil target known as "Tyrone" and continued acquiring panoramic camera images of the rover's winter haven.
Sol 1048: Spirit acquired thumbnail images of the sky with the panoramic camera and scanned the sky for clouds with the navigation camera. The rover monitored atmospheric dust with the panoramic camera, and surveyed the sky, ground, and calibration target with the miniature thermal emission spectrometer.
Sol 1049: Spirit acquired navigation camera images in support of miniature thermal emission spectrometer measurements of the rover's surroundings. The rover monitored atmospheric dust with the panoramic camera and acquired panoramic images of the area ahead.
Sol 1050 (Dec. 16, 2006): Spirit's instructions call for scanning for clouds and dust devils with the navigation camera, surveying the mast for dust accumulation and observing the sky and ground with the miniature thermal emission spectrometer.
Odometry:
As of sol 1048 (Dec. 14, 2006), Spirit's total odometry was 6,885.62 meters meters (4.28 miles).
sol 1039-1042, December 08, 2006: Spirit Slowly Resumes Driving on Martian Terrain
Despite a non-functioning right front wheel, Spirit is healthy and on the move. The rover completed short drives on Martian days, or sols, 1039 (Dec. 5, 2006) and 1041 (Dec. 7, 2006) on its way toward a rock target informally named "Esperanza."
Sol-by-sol summary:
Sol 1039 (Dec. 5, 2006): Spirit drove 1 meter (3.3 feet) and acquired images after the drive using the hazard avoidance and navigation cameras. The rover took a super-resolution image with the panoramic camera and scanned the Martian sky for clouds with the navigation camera.
Sol 1040: Spirit scanned the sky, ground, and Esperanza using the miniature thermal emission spectrometer. The rover surveyed the sky and the horizon with the panoramic camera.
Sol 1041: Spirit turned in the direction of Esperanza, then drove another 1.5 meters (5 feet) toward the rock. Spirit acquired more detailed images after the drive with the hazard avoidance camera and a 360-degree view of the rover's surroundings with the navigation camera. The rover searched the sky for clouds with the navigation camera and took panoramic images of the "El Dorado" dune field and the Martian sky.
Sol 1042 (Dec. 8, 2006): Spirit panoramic camera took images for a full-color, 13-filter mosaic of the area studied by the rover during the last Martian winter. Spirit also scanned the area with the miniature thermal emission spectrometer.
Odometry:
As of sol 1039 (Dec. 5, 2006), Spirit's total odometry was 6,880.86 meters (4.28 miles).
sol 1024-1038, December 05, 2006: Spirit Slowly Begins Driving Again
Spirit is healthy and preparing to drive away from the rover's winter station after completing scientific investigation of a rock nicknamed "King George Island." The rock, according to principal investigator Steve Squyres, contains some of the best-rounded grains ever seen in a Martian rock. Scientists will try to determine how the grains formed -- perhaps with help from wind or water.
Spirit arrived at King George Island on Sol 1022 (Dec. 17, 2006) after a short bump (very short drive) from a disturbed soil target nicknamed "Bear Island." Upon arrival, Spirit took a mosaic of microscopic images of King George and collected data using the alpha-particle X-ray and Mössbauer spectrometers. Spirit then brushed the target with the wire bristles on the rock abrasion tool before collecting more alpha-particle X-ray and Mössbauer data for comparison with data from the unbrushed surface.
Spirit's next planned target is a rock aptly nicknamed "Esperanza," the Spanish word for hope. The first of several drives to reach that goal began on Sol 1037 (Dec. 3, 2006). On Sol 1030 (Nov. 25, 2006), the Mars Reconnaissance Orbiter used its high-resolution camera to acquire images of Spirit's "Winter Haven," where the rover has spent its second Martian winter, and of Spirit's lander, which arrived on Mars Jan. 4, 2004.
Sol-by-sol summaries:
In addition to Spirit's daily science observations, which include measuring atmospheric dust opacity with the panoramic camera, surveying the sky and ground using the miniature thermal emission spectrometer, and scanning the Martian sky for clouds using the navigation camera, the Mars rover did the following work:
Sol 1024 (Nov. 19, 2006): Spirit collected data about the Martian atmosphere using the alpha-particle X-ray spectrometer and monitored dust accumulation on the panoramic camera mast.
Sol 1025: Spirit acquired super-resolution panoramic camera images of the circular plateau-like feature known as "Home Plate" and measured the amount of light detectable at night and during Martian twilight.
Sol 1026: Spirit coordinated daily science observations with an overflight of the Mars Reconnaissance Orbiter. The rover measured surface reflectivity using the panoramic camera.
Sol 1027: Spirit acquired a mosaic of images of King George Island and collected data from the same rock target using the alpha-particle X-ray spectrometer.
Sol 1028: Spirit studied King George Island using the Mössbauer spectrometer.
Sol 1029: Spirit studied Esperanza and two other rock targets known as "Zhong Shan" and "Korolev" using the miniature thermal emission spectrometer.
Sol 1030: Spirit continued to assess King George Island using the Mössbauer spectrometer and investigated a distant rock outcrop known as "Oberth" using the miniature thermal emission spectrometer.
Sol 1031: Spirit brushed the surface of King George Island using the rock abrasion tool and acquired microscopic images and alpha-particle X-ray data of the freshly brushed surface.
Sol 1032: Spirit acquired Mössbauer data from the brushed surface of King George Island.
Sol 1033: Spirit acquired information about rock targets known as "Syowa" and "Wiltgen" using the miniature thermal emission spectrometer.
Sol 1034: Spirit collected microscopic images of two soil targets known as "Clarence" and "Deception" and recommenced analysis of the brushed surface of King George Island using the Mössbauer spectrometer.
Sol 1035: Spirit analyzed a spot on the same rock surface but offset from the target known as King George Island by acquiring microscopic images and collecting corresponding compositional data with the alpha particle X-ray spectrometer.
Sol 1036: Spirit acquired a 13-filter, full-color panorama of the soil target known as "Tyrone" and again analyzed Korolev and Esperanza from a distance using the miniature thermal emission spectrometer.
Sol 1037: Spirit stowed the robotic arm carrying scientific instruments and began driving toward Esperanza.
Sol 1038 (Dec. 4, 2006): Spirit tested new capabilities for automated placement of the robotic arm.
Odometry:
As of sol 1036 (Dec. 2, 2006), Spirit's total odometry was 6,877.63 meters (4.27 miles).
sol 1017-1023, December 04, 2006: More Remote Science for Spirit
Spirit is healthy. Downlink of information from the rover resumed after a 48-hour gap in downlink that resulted from NASA's Mars Odyssey releasing most of its Deep Space Network coverage earlier in the week to Mars Global Surveyor to support efforts to recover communications with Global Surveyor.
This week, Spirit changed robotic-arm targets from "Berkner Island" to "Bear Island" and executed a microscopic image mosaic, five hours of data collection with the alpha particle X-ray spectrometer and nearly 48 hours with the Mössbauer spectrometer. The engineering team planned and commanded Spirit's second drive of the season on sol 1022.
Sol-by-sol summaries:
Sol 1017 (Nov. 12, 2006): Spirit used its microscopic imager to take exposures for a stereo mosaic of target Bear Island, then placed the alpha particle X-ray spectrometer on that target. After the Mars Odyssey pass, the rover took a tau (atmospheric clarity) measurement and then began a five-hour reading with the alpha particle X-ray spectrometer.
Sol 1018: The panoramic camera took thumbnail images of the sky, and the navigation camera scanned for clouds. The team changed tools to the Mössbauer spectrometer and used it for a 10-hour integration on Bear Island.
Sol 1019: In the morning, the miniature thermal emission spectrometer assessed the sky and ground, and the panoramic camera examined the sky. The miniature thermal emission spectrometer then stared at target "Baudoin." Some engineering maintenance was done and then the Mössbauer spectrometer was restarted on target Bear Island.
Sol 1020: In the morning, the miniature thermal emission spectrometer assessed the sky and ground, and the panoramic camera examined the sky. The rover restarted the Mössbauer data-collection on Bear Island for a 23-hour, overnight integration.
Sol 1021: Spirit's miniature thermal emission spectrometer assessed light-toned material in the rover's tracks in the morning. The Mössbauer spectrometer was restarted on Bear Island. The panoramic camera conducted a light experiment by taking multiple images throughout the day. The miniature thermal emission spectrometer assessed target "Allan Hills" during the communications pass with Mars Odyssey. After the Odyssey pass, the Mössbauer observation was completed and the panoramic camera took a tau measurement at sunset.
Sol 1022: Spirit's arm was stowed before the rover began a short drive to a nearby outcrop. After the drive the navigation and hazard avoidance cameras took images. A tau measurement was taken as well.
Sol 1023 (Nov. 28): The panoramic camera took images of targets "El Dorado" and "Prat" as well as thumbnail images of the sky. The miniature thermal emission spectrometer conducted a sky and ground observation.
Odometry:
As of sol 1023, Spirit's odometry is 6,877.63 meters (4.27 miles).
sol 1013-1016, November 13, 2006: Spirit's 'Arm' Busy Checking New Targets
After Spirit's successful 0.71-meter (28-inch) bump on sol 1010, the team has new targets in the robotic arm's work volume for the first time in 204 sols. There is some interesting light and dark material within arm's reach and this week the team planned a robotic arm campaign including a microscopic imager mosaic, four hours of alpha particle X-ray spectrometer integration and 43 hours of Mössbauer spectrometer integration. Spirit is receiving a little over 320 Watt-hours now and is able to occasionally use the Mössbauer or alpha particle X-ray spectrometer overnight.
Sol-by-sol summary:
Sol 1013 (Nov. 8, 2006): This sol began with the usual engineering block tau (atmospheric clarity) measurement, then a calibration of the miniature thermal emission spectrometer before that instrument was used to stare at the sky and ground. Spirit then used its front hazard avoidance cameras to look at the robotic arm's work volume, then unstowed the arm and took a stereo microscopic image of target "Berkner Island." The rover then placed the alpha particle X-ray spectrometer on Berkner Island and integrated for four hours. Spirit used its miniature thermal emission spectrometer to stare at target "Davis" during the afternoon when NASA's Mars Odyssey spacecraft passed overhead.
Sol 1014: The rover changed tools to the Mössbauer spectrometer and integrated for 23 hours.
Sol 1015: During the morning of this sol, Spirit conducted dust monitoring of its panoramic camera mast assembly (its neck and head). The rover then restarted the Mössbauer on target Berkner Island for a 10-hour integration. A panoramic camera tau measurement and a miniature thermal emission spectrometer observation of sky and ground were conducted around the Odyssey pass.
Sol 1016: On this sol, Spirit took images with its navigation camera. It then restarted the Mössbauer spectrometer on Berkner Island for a 10-hour integration. Total integration time is 43 hours at this target. The rover then conducted a panoramic camera sky observation.
Odometry:
As of sol 1016 (Nov. 11, 2006), Spirit's odometry is 6,876.89 meters (4.27 miles).
sol 1006-1012, November 07, 2006: Spirit Passes 1000 Sols and Continues its Winter Campaign
Spirit is healthy and is starting to stir from its winter resting spot.
Sols 1006 through 1009 were spent working on winter campaign observations; Spirit is entering the final phase of these observations.
Sol 1010 saw Spirit stir from its winter resting spot with a 33-degree turn and a 0.71-meter (28-inch) bump. This was done so that Spirit could reach the bright soil pushed up by its right front wheel when the rover arrived here about 200 sols ago.
On Sol 1011 Spirit performed a coordinated experiment with NASA's Mars Reconnaissance Orbiter. This test was performed to characterize performance of the orbiter's UHF Electra radio. Mars Reconnaissance Orbiter will provide data relay services for NASA's Phoenix Mars Lander, which is scheduled to arrive at Mars in May 2008.
Sol-by-sol summary:
Sol 1006 (Nov. 1, 2006): Spirit assessed atmospheric clarity (a "tau" measurement) with its panoramic camera, calibrated its miniature thermal emission spectrometer and then used that instrument to stare at the sky and ground. The rover's microscopic imager was used to image the rover's magnet array and a solar panel. During the communication window with NASA's Mars Odyssey, the rover again used the miniature thermal emission spectrometer to look at the sky and ground. After the Odyssey pass, the panoramic camera imaged the sunset.
Sol 1007: In the morning of this sol, Spirit's miniature thermal emission spectrometer measured a dust spot. A tau measurement was taken by the panoramic camera and the miniature thermal emission spectrometer checked out the sky and ground. The microscopic imager took images for stereo mosaics and the miniature thermal emission spectrometer was calibrated.
Sol 1008: This morning Spirit used its navigation camera to look for clouds and then used its miniature thermal emission spectrometer to look at the sky and ground. The rover then used its panoramic camera to do a tau measurement before the miniature thermal emission spectrometer was used again. The microscopic imager was then used on targets "Palmer" and "Mawson." The arm was stowed and then the panoramic camera did a light check before it imaged the sunset.
Sol 1009: Spirit used its navigation camera this morning to look for clouds and then took thumbnail images of the sky with its panoramic camera. The panoramic camera also surveyed the horizon. The miniature thermal emission spectrometer completed a sky and ground observation before the Odyssey pass. During the communication window with Odyssey, the spectrometer stared at target "Casey Station." After the Odyssey pass the rover did a tau measurement with the panoramic camera and began to use the alpha particle X-ray spectrometer on "Argon."
Sol 1010: During the morning of this sol, Spirit used its panoramic camera to image "El Dorado." The hazard avoidance cameras were aimed at some fine ripples to assess them. The miniature thermal emission spectrometer stared at some Martian dust and the panoramic camera assessed the atmosphere. Again, the miniature thermal emission spectrometer was used to stare at the sky and ground. The rover was commanded to do a "bump," or very short movement. Post-bump images were taken with the navigation camera and the hazard avoidance cameras.
Sol 1011: Spirit used its panoramic camera to have a look at the sky before it began to take a large panoramic image. The miniature thermal emission spectrometer was used to look at the sky and ground before Spirit interacted with its Martian partner overhead, the Mars Reconnaissance Orbiter.
Sol 1012 (Nov. 7, 2006): On this sol, the panoramic camera was used to finish the panorama it began "yestersol." The panoramic camera took a tau measurement before the miniature thermal emission spectrometer had a look at the sky and ground.
Odometry:
As of sol 1010 (Nov. 5, 2006), Spirit's total odometry is 6,976.89 meters (4.34 miles).
sol 982-987, October 16, 2006: Approaching Solar Conjunction
As Spirit enters a period known as solar conjuction, when the sun interferes with transmissions between Mars and Earth, mission planners sent a complete set of plans for science activities during solar conjunction to Spirit on the rover's 982nd sol, or Martian day, of exploring inside Gusev Crater (Oct. 7, 2006). During that time, the rover will achieve a new milestone: exploring Mars for 1,000 consecutive days.
Solar conjunction will begin on sol 991 (Oct. 16, 2006) and end on sol 1015 (Nov. 10, 2006). During this period, both NASA rovers, Spirit and Opportunity, will not receive any new command loads, but they will send daily downlinks to Earth, averaging 15 megabits of data per transmission. The data will be relayed to Earth via NASA's Mars Odyssey spacecraft in orbit above Mars.
Each day during conjunction, Spirit will spend 3 hours analyzing dust collected on the rover's filter magnet using the Mössbauer spectrometer and 24 minutes conducting a variety of early morning science observations. The morning science activities are designed to monitor the atmosphere and to search for any possible surface changes. The workload will make optimum use of solar power levels available with the retreat of Martian winter.
Spirit is healthy and continues to make progress on the winter science campaign of experiments. The rover's solar energy levels continue to rise slowly. Solar power is currently about 300 watt-hours. One hundred watt-hours is the amount of electricity needed to light one 100-watt bulb for one hour.
Sol-by-sol summary:
Sol 982 (Oct. 7, 2006): Spirit measured atmospheric dust opacity with the panoramic camera and surveyed the sky, ground, and dark soil in the rover's tracks using the miniature thermal emission spectrometer. Spirit took panoramic camera images of the rover's tracks and analyzed rock targets known as "Gueslaga" and "Tor" with the miniature thermal emission spectrometer. The rover measured the brightness of the morning sky in the west using the panoramic camera.
Sol 983: Spirit measured atmospheric dust opacity with the panoramic camera and surveyed the sky, ground, and dark soil in the rover's tracks using the miniature thermal emission spectrometer. Spirit took a look at the elemental chemistry of the atmosphere with the alpha particle X-ray spectrometer. The rover acquired super-resolution panoramic camera images of a target called "Mitcheltree Ridgecrest 11."
Sol 984: Spirit measured atmospheric dust opacity with the panoramic camera and surveyed the sky, ground, and soil in the rover's tracks using the miniature thermal emission spectrometer. Spirit analyzed a rock target dubbed "O'Higgins" with the miniature thermal emission spectrometer and referenced instrument measurements to the calibration target on the rover. The rover scanned the sky for clouds with the navigation camera, measured morning sky brightness with the panoramic camera, and monitored dust on the panoramic camera mast assembly.
Sol 985: Spirit measured atmospheric opacity using the panoramic camera, surveyed the sky and ground with the miniature thermal emission spectrometer, and restarted analysis of dust collected by the filter magnets using the Mössbauer spectrometer. Spirit scanned the sky for clouds using the navigation camera and acquired thumbnail images of the sky with the panoramic camera.
Sol 986: Spirit measured atmospheric opacity using the panoramic camera, checked for drift (changes with time) in the miniature thermal emission spectrometer, and surveyed the sky and ground with the miniature thermal emission spectrometer. Spirit scanned the sky for clouds using the navigation camera and acquired thumbnail images of the sky with the panoramic camera.
Sol 987 (Oct. 12, 2006): Spirit measured atmospheric dust opacity using the panoramic camera, checked for drift in the miniature thermal emission spectrometer, and surveyed the sky and ground with the miniature thermal emission spectrometer. The rover restarted Mössbauer analysis of dust on the filter magnets. Spirit surveyed the sky during high sun using the panoramic camera.
Odometry:
As of sol 986 (Oct. 11, 2006), Spirit's total odometry remained at 6,876.18 meters (4.27 miles).
sol 977-981, October 13, 2006: Spirit Studies Layers of Volcanic Rock
Spirit is healthy and continues to make progress on a winter science campaign of experiments.
In parallel with normal planning, a special team has been developing plans to be executed during solar conjunction, when the sun obscures the line of sight between Earth and Mars and severely limits radio communication. Rover handlers will upload the plans to be executed by Spirit during solar conjunction prior to the beginning of conjunction. This year's solar conjunction period begins on the rover's 991st Martian day, or sol, (Oct. 16, 2006) and ends on sol 1005 (Oct. 30, 2006). Planning for future activities on sols 1006 and 1007 (Oct. 31 to Nov. 1, 2006) will resume Oct. 30.
Spirit continued to produce atmospheric profiles of dust, temperature at different heights, ice, and water vapor, as well as surface and sub-surface temperatures using the miniature thermal emission spectrometer. Plans also called for a scan of the sky for clouds, which, if found, could be incorporated into a multi-frame movie for observing cloud movement.
Spirit acquired super-resolution panoramic camera images of volcanic outcrops called "Marambio," "Jubany," and "Mitcheltree Ridge" on sols 979 and 981 (Oct. 4 and Oct. 6, 2006). The outcrops consist of basalt, a dense, dark rock that hardens from lava and often has a glassy appearance. These basalts were also vesicular, meaning they are porous because there were gas bubbles in the lava when it solidified.
The purpose of the super-resolution imaging campaign is to identify and map characteristics of the local geology. In particular, scientists hope to determine the relative stratigraphy of Mitcheltree Ridge, "Low Ridge," and the raised, circular plateau known as "Home Plate." Stratigraphy is the study of rock layers.
Spirit's solar energy levels continued to rise, ending the week at around 300 watt-hours. One hundred watt-hours is the amount of electricity needed to light one 100-watt bulb for one hour.
Sol-by-sol summary:
Sol 977 (Oct. 2, 2006): Spirit measured atmospheric opacity using the panoramic camera, surveyed the sky and ground with the miniature thermal emission spectrometer, used the Mössbauer spectrometer to analyze dust collected by the filter magnets, acquired panoramic camera images of the work volume accessible by the robotic arm, and collected images of the rover's tracks with the miniature thermal emission spectrometer.
Sol 978: Spirit measured atmospheric opacity using the panoramic camera, surveyed the sky and ground with the miniature thermal emission spectrometer, and collected thermal data from targets known as "Casey Station" and "Sobral." The rover acquired super-resolution images of volcanic rock outcrops called Marambio and Jubany and measured morning sky brightness in the west with the panoramic camera.
Sol 979: Spirit measured atmospheric dust opacity using the panoramic camera, surveyed the sky and ground with the miniature thermal emission spectrometer, and restarted integration of data from the Mössbauer spectrometer's inspection of dust on the filter magnets. In addition, Spirit acquired morning images of the dune field known as "El Dorado" as well as images of the Martian horizon using the panoramic camera, measured morning sky brightness in the west with the panoramic camera, and scanned the sky for clouds using the navigation camera.
Sol 980: Spirit measured atmospheric dust opacity using the panoramic camera, surveyed the sky and ground with the miniature thermal emission spectrometer, surveyed the sky with the panoramic camera, and acquired super-resolution images of Mitcheltree Ridge with the panoramic camera.
Sol 981 (Oct. 6, 2006): Spirit measured atmospheric dust opacity using the panoramic camera, surveyed the sky and ground with the miniature thermal emission spectrometer, restarted integration of data from the filter magnets with the Mössbauer spectrometer, and acquired super-resolution panoramic camera images of the soil target known as "Tyrone."
Odometry:
As of sol 981 (Oct. 6, 2006), Spirit's total odometry remained at 6,876.18 meters (4.27 miles).
sol 970-976, September 29, 2006: Solar Power Is on the Rise as Spirit 'Follows the Water'
Solar power levels on Spirit are slowly beginning to rise again following a winter low of 275 watt-hours on Martian day, or sol, 933 (Aug. 18, 2006). One hundred watt-hours is the amount of electricity needed to light one 100-watt bulb for one hour. This week, the rover's power levels rose to about 296 watt-hours.
Spirit spent much of the week analyzing atmospheric dust attracted to magnets on the spacecraft. The rover identifies iron minerals in the dust using the Mössbauer spectrometer. One of the two magnets, the filter magnet, is weaker than the capture magnet, allowing scientists to separate mineral grains that have the highest magnetic susceptibility, particularly minerals that contain iron.
During the week, Spirit studied rock targets known as "Juan Carlos," "Gueslaga," and "Tor" using the miniature thermal emission spectrometer. Juan Carlos and Tor are vesicular rocks filled with tiny holes that formed during the cooling of a froth of magma and gas. Scientists hope to determine whether these rocks are similar to or different from nearby smooth-textured volcanic rocks known as basalts. Gueslaga, meanwhile, is an entirely different kind of rock known as an "exotic," meaning it came from somewhere else and may have been emplaced during an impact event.
Spirit continued to make scientific observations of the soil target known as "Tyrone." Tyrone is a patch of bright material, white and yellow in color, that is possibly analogous to salty soils examined earlier in the mission known as "Arad" and "Paso Robles." Spirit's dragging right front wheel churned up the bright material on the rover's 784th sol of exploration of Mars (March 18, 2006). Some science team members have speculated that some component in this material is hydrated. If moisture enters or leaves the material, the miniature thermal emission spectrometer would be able to detect it. Scientists are also monitoring the soil with the rover's panoramic camera for any color changes, because variability in water content could affect the color. These observations are ongoing to account for seasonal variability.
The rover continues to operate successfully with the new flight software package.
Sol-by-sol summaries:
Sol 970 (Sept. 25, 2006): Spirit measured atmospheric opacity using the panoramic camera, surveyed the sky and ground with the miniature thermal emission spectrometer, analyzed dust on the filter magnet with the Mössbauer spectrometer, acquired morning images of the spacecraft deck with the panoramic camera, and scanned the sky for clouds with the navigation camera.
Sol 971: Spirit measured atmospheric opacity using the panoramic camera, surveyed the sky and ground with the miniature thermal emission spectrometer, collected data from the rock target known as Juan Carlos, and surveyed the horizon using the panoramic camera.
Sol 972: Spirit measured atmospheric opacity using the panoramic camera, surveyed the sky and ground with the miniature thermal emission spectrometer, restarted integration of data from the filter magnets with the Mössbauer spectrometer, acquired panoramic camera images of the work volume accessible by the robotic arm, and measured morning sky brightness in the west with the panoramic camera.
Sol 973: Spirit measured atmospheric opacity using the panoramic camera, surveyed the sky and ground with the miniature thermal emission spectrometer, studied the rock targets Gueslaga and Tor using the miniature thermal emission spectrometer, and used the panoramic camera to take images of rover tracks and measure morning sky brightness in the west.
Sol 974: Plans called for Spirit to measure atmospheric opacity using the panoramic camera, survey the sky and ground with the miniature thermal emission spectrometer, restart integration of data from the filter magnets with the Mössbauer spectrometer, survey the sky and ground with the miniature thermal emission spectrometer, scan the sky for clouds, measure morning sky brightness, and take a morning measurement of dust on the panoramic camera mast assembly with the miniature thermal emission spectrometer.
Sol 975: Plans called for Spirit to measure atmospheric opacity using the panoramic camera, survey the sky and ground with the miniature thermal emission spectrometer, and acquire morning images of the rover's tracks with all 13 filters of the panoramic camera.
Sol 976 (Oct. 1, 2006): Plans called for Spirit to measure atmospheric opacity using the panoramic camera, survey the sky and ground using the miniature thermal emission spectrometer, continue analysis of dust on the filter magnets with the Mössbauer spectrometer, and complete a morning sky survey with the panoramic camera.
Odometry:
As of sol 973 (Sept. 28, 2006), Spirit's total odometry remained at 6,876.18 meters (4.27 miles).
sol 964-969, September 22, 2006: Spirit Activates New Software
Following some dramatic scrambling by rover handlers to command both Mars Exploration Rovers to switch to new flight software during a bit of a traffic jam at the Red Planet, Spirit successfully woke up and began operating with the new software. The X-band frequency for communicating directly with Earth had become unavailable while being used by NASA's Mars Reconnaissance Orbiter during critical events for that mission. As in the past, engineers were able to use the UHF-band frequency to relay commands indirectly to the rovers via NASA's Mars Odyssey orbiter. Time was of the essence in order to begin running and testing the new software before solar conjunction in October, when Mars will be on the opposite side of the sun from Earth and radio communication will be intermittent for a couple of weeks.
The new software gives the rover enhanced autonomous operational capabilities to be tested in coming months.
Sol-by-sol summary:
Sol 964 (Sept. 19, 2006): Spirit halted operations temporarily while awaiting instructions from Earth. Rover handlers originally planned to have the rover reboot using the new flight software by sending a command over the X-band uplink. The X-band became unavailable when it was needed by the Mars Reconnaissance Orbiter. The team sent the reboot command via the UHF-band antenna on the Odyssey orbiter later the same day.
Sol 965: At 11 a.m. local solar time on Mars, Spirit woke up for the first time running the new flight software, known as version R9.2. Later the same sol, or Martian day, Spirit ran a series of engineering sequences to establish operating parameters for data products and imaging.
Sol 966: Spirit set operating parameters for driving and operating the rover's robotic arm. The rover measured atmospheric dust using the panoramic camera.
Sol 967: Plans called for Spirit to continue to test the new software. Science activities remained light as the uplink team waited for both Spirit and Spirit's twin, Opportunity, on the other side of Mars, to reboot using the new software.
Sol 968: Plans called for Spirit to return to relatively normal science operations without moving the robotic arm, while team members awaited confirmation that the rover had established the correct operating parameters for the arm. Spirit was to complete 5 hours of analysis of dust on the rover's capture magnet using the alpha particle X-ray spectrometer.
Sol 969 (Sept. 24, 2006): Plans called for Spirit to measure surface reflectivity with the panoramic camera, measure atmospheric dust, and complete a morning scan of the sky and ground with the miniature thermal emission spectrometer, followed by similar observations in the afternoon. Spirit was also instructed to measure sky brightness, check for changes over time in the panoramic camera, and study a soil target known as "Tyrone" with the miniature thermal emission spectrometer.
Odometry:
As of sol 965 (Sept. 20, 2006), Spirit's total odometry remained at 6,876.18 meters (4.27 miles).
sol 957-963, September 14, 2006: The Martian Sun Also Rises as Winter Retreats
Spirit is beginning to see an upward trend in electrical power as winter slowly recedes and the sun ascends higher in the sky each day. Electrical power from the rover's solar array rose to 287 watt-hours on the rover's 958th Martian day, or sol (Sept. 12, 2006) of exploration, compared with 277 watt-hours on sol 944 (Aug. 29, 2006). One hundred watt-hours is the amount of electricity needed to light one 100-watt bulb for one hour.
During the past week, Spirit conducted 10 hours of analysis of the elemental composition of dust on the rover's magnets using the alpha particle X-ray spectrometer. Spirit also finished taking images of the spacecraft deck.
Sol-by-sol summaries:
Sol 957 (Sept. 11, 2006): Spirit continues to complete the same set of observations each sol in parallel with engineering activities such as data management. The engineering block of activities includes monitoring atmospheric dust with the panoramic camera, and surveying the sky and ground with the miniature thermal emission spectrometer. On this particular sol, Spirit demonstrated additional multi-tasking abilities by acquiring data on a rock target known as "Vostok" using the miniature thermal emission spectrometer while transmitting data to the Odyssey spacecraft as it passed overhead.
Sol 958: Spirit acquired part 13 of the 15-part image mosaic of the spacecraft deck with the panoramic camera. Spirit spent about five hours acquiring data on the elemental composition of dust on the rover's filter magnets using the alpha particle X-ray spectrometer.
Sol 959: Spirit acquired panoramic camera images of a soil target consisting of bright material in the rover's tracks known as "Tyrone."
Sol 960: Plans called for Spirit to continue to acquire panoramic images of the rover deck, restart the alpha particle X-ray spectrometer following the overhead pass of the Odyssey spacecraft, and spend 4 hours and 50 minutes collecting elemental data of dust on the filter magnets. Plans also called for a morning measurement of sky brightness in the west with the panoramic camera (known as a pancam skyspot), a search for clouds using the navigation camera, a horizon survey with the panoramic camera, imaging of the "El Dorado" dune field with the panoramic camera, and imaging of ripples with the rear hazard avoidance camera.
Sol 961: Plans called for Spirit to acquire data from a target known as "Macquarie" with the miniature thermal emission spectrometer, acquire data from the calibration target with the miniature thermal emission spectrometer, and search for clouds with the navigation camera.
Sol 962: Plans called for Spirit to acquire the last segment of the 15-part panoramic mosaic of the spacecraft deck and conduct a 4-hour and 35-minute alpha particle X-ray spectrometer analysis of the filter magnets. Plans also called for Spirit to acquire sky images with the panoramic camera and validate measurements of complete darkness by the panoramic camera.
Sol 963 (Sept. 18, 2006): Plans called for Spirit to acquire images of the rover's tracks with the navigation camera, take microscopic images of the filter and capture magnets, and place the alpha particle X-ray spectrometer on the capture magnet. Plans also called for the rover to acquire hazard avoidance camera images of the work volume reached by the rover's robotic arm, monitor dust on the panoramic camera mast assembly, survey the horizon with the panoramic camera, and search for morning clouds with the navigation camera.
Odometry:
As of sol 958 (Sept. 12, 2006), Spirit's total odometry remained at 6,876.18 meters (4.27 miles).
sol 950-956, September 08, 2006: Spirit Monitors Dust and Searches for Clouds
Spirit is healthy and continues to make progress on the rover's winter science campaign. During the past week, Spirit continued filling in sections of the rover's deck as part of the "Deck Pan" mosaic of panoramic images.
Electrical power from the rover's solar array has continued to hold steady at approximately 280 watt-hours per sol (a hundred watt-hours is the amount of electricity needed to light one 100-watt bulb for one hour).
Sol-by-sol summaries:
Sol 950 (Sept. 4, 2006): Spirit collected images of the rover deck with the panoramic camera, checked the atmosphere for opacity caused by dust, and scanned the sky and ground with the miniature thermal emission spectrometer.
Sol 951: Spirit collected images of the rover deck with the panoramic camera, checked the atmosphere for opacity caused by dust, and scanned the sky and ground with the miniature thermal emission spectrometer.
Sol 952: Spirit collected images of the rover deck with the panoramic camera, checked the atmosphere for opacity caused by dust, and scanned the sky and ground with the miniature thermal emission spectrometer.
Sol 953: Plans called for Spirit to acquire images of the sun high in the sky and acquire data from rock targets known as "Primero" and "Castilla" using the miniature thermal emission spectrometer. Plans also included checking the atmosphere for opacity caused by dust and scanning the sky and ground with the miniature thermal emission spectrometer.
Sol 954: Plans called for Spirit to acquire panoramic camera images of the capture and filter magnets (two dust-collecting magnets on the rover deck), search for clouds using the navigation camera, check the atmosphere for opacity caused by dust, and scan the sky and ground with the miniature thermal emission spectrometer.
Sol 955: Plans called for Spirit to acquire images of the rover deck, microscopic images of the capture magnet, and miniature thermal emission spectrometer data on a rock target known as "Signy." The rover was also slated to make daily observations of the sky and ground with the panoramic camera and miniature thermal emission spectrometer.
Sol 956 (Sept. 11, 2006): Plans called for Spirit to collect images of the rover deck with the panoramic camera and microscopic images of the filter magnet, as well as make the usual daily observations of the sky and ground with the panoramic camera and miniature thermal emission spectrometer.
Odometry:
As of sol 952 (Sept. 6, 2006), Spirit's total odometry remained at 6,876.18 meters (4.27 miles).
Spirit experienced a software reset during the evening overpass of the Odyssey orbiter on sol 944 (Aug. 29, 2006). The rover was in the process of receiving command sequences for the following two Martian days, sols 945 and 946 (Aug. 30-31, 2006). As a result of the reset, the rover went into automode, meaning the rover did not attempt to execute a master sequence of activities for the day. The apparent cause was that the rover's central processing unit was overworked as several tasks were running in parallel at the time. Engineers transmitted a new, abbreviated plan of activities on sol 946 along with the plan of activities for sol 947 (Sept. 1, 2006).
Spirit is healthy and continues to make progress on the rover's winter science campaign. The rover spent part of the week filling in sections of the rover deck for the "McMurdo panorama." Electrical power from the rover's solar array has been holding steady at about 280 watt-hours per sol (a hundred watt-hours is the amount of electricity needed to light one 100-watt bulb for one hour).
Sol-by-sol summaries:
Sol 943 (Aug. 28, 2006): Spirit acquired sky images with the navigation camera. The rover scanned the atmosphere for opacity caused by dust and scanned the sky and ground with the miniature thermal emission spectrometer.
Sol 944: Spirit acquired microscopic images of the soil target known as "Halley Brunt." Spirit scanned the atmosphere for opacity caused by dust and scanned the sky and ground with the miniature thermal emission spectrometer.
Sol 945: Spirit experienced a software reset and went into automode, meaning the rover did not attempt to execute a master sequence of activities for the day. The apparent cause was that the rover's central processing unit was overworked.
Sol 946: Spirit remained in automode. Engineers transmitted an abbreviated plan of activities for the sol along with the plan of activities for sol 947.
Sol 947: Plans called for Spirit to acquire fill-in images for the McMurdo panorama and to continue to make daily observations of the sky and ground with the panoramic camera and the miniature thermal emission spectrometer.
Sol 948: Plans called for Spirit to acquire Mössbauer data on the soil target called "Halley Brunt" and to continue to make daily observations of the sky and ground with the panoramic camera and the miniature thermal emission spectrometer.
Sol 949 (Sept. 3, 2006): Plans called for the rover to acquire fill-in frames for the McMurdo panorama and to continue to make daily observations of the sky and ground with the panoramic camera and the miniature thermal emission spectrometer.
Odometry:
As of sol 945 (Aug. 30, 2006), Spirit's total odometry remained at 6,876.18 meters (4.27 miles).
sol 933-942, August 25, 2006: Spirit Continues Mid-Winter Studies of Martian Rocks and Soil
Spirit continued to make progress on the rover's winter campaign of science observations, acquiring microscopic images and data about rock composition with the alpha particle X-ray spectrometer and the miniature thermal emission spectrometer. Spirit took images of the spacecraft deck for incorporation into the "McMurdo panorama."
Spirit remains healthy. Electrical power from the rover's solar array has been holding steady at about 280 watt-hours per sol (a hundred watt-hours is the amount of electricity needed to light one 100-watt bulb for one hour).
Sol-by-sol summaries:
Sol 933 (Aug. 18, 2006): Spirit acquired super-resolution images of a basalt hill nicknamed "Dome Fuji" with the panoramic camera and monitored dust on the pancam mast assembly. Spirit scanned the atmosphere for opacity caused by dust and scanned the sky and ground with the miniature thermal emission spectrometer.
Sol 934: Spirit acquired touch-up images for the McMurdo panorama with the panoramic camera. Spirit scanned the atmosphere for opacity caused by dust and scanned the sky and ground with the miniature thermal emission spectrometer.
Sol 935: Spirit acquired panoramic camera images of a rock target called "Prat" and measured the magnitude of sunlight in addition to scanning the horizon and sky with the panoramic camera and miniature thermal emission spectrometer.
Sol 936: Spirit acquired data from a rock target called "Wasa" with the miniature thermal spectrometer. The rover continued to make daily observations of the sky and ground with the panoramic camera and miniature thermal emission spectrometer.
Sol 937: Spirit acquired microscopic images of a ripple called "Palmer" and scanned for wind-related changes in a sand target known as "Rothera." Spirit continued to make daily observations of the sky and ground with the panoramic camera and miniature thermal emission spectrometer.
Sol 938: Spirit acquired super-resolution, panoramic camera images of a possible meteorite candidate known as "Vernadsky." The rover continued to make daily observations of the sky and ground with the panoramic camera and miniature thermal emission spectrometer.
Sol 939: Spirit acquired super-resolution, panoramic camera images of a target known as "Scott Base." Spirit continued to make daily observations of the sky and ground with the panoramic camera and miniature thermal emission spectrometer.
Sol 940: Plans called for Spirit to acquire images of the rover deck with the panoramic camera and acquire miniature thermal emission spectrometer data on a rock target known as "Law-Racovita." Plans called for continued daily observations of the sky and ground with the panoramic camera and miniature thermal emission spectrometer.
Sol 941: Plans called for Spirit to acquire panoramic camera images of the rover deck as well as continue to make daily observations of the sky and ground with the panoramic camera and miniature thermal emission spectrometer.
Sol 942 (Aug. 27, 2006): Plans called for Spirit to continue acquiring panoramic camera images of the rover deck, collect data about elemental composition of the rock target called "Halley Brunt," and make daily observations of the sky and ground with the panoramic camera and miniature thermal emission spectrometer.
Odometry:
As of sol 938 (Aug. 23, 2006), Spirit's total odometry remained at 6,876.18 meters (4.27 miles).
sol 929-932, August 18, 2006: Spirit Checking 'Korolev'
Spirit is healthy and continues to make progress on its winter science campaign.
Spirit is finishing the "McMurdo mega-panorama" by acquiring touch-up images (dubbed "grout" by engineers). Spirit is nearly complete with the coverage of the ground around the rover.
Spirit continues making a series of atmospheric observations at the same time each day.
Spirit is collecting about 280 watt-hours of electrical power each sol from the rover's solar array (100 watt-hours is the amount of electricity needed to light one 100-watt bulb for one hour).
Sol-by-sol summaries:
Sol 929 (Aug. 14, 2006): Spirit studied a target called "Halley Brunt" with the panoramic camera and microscopic imager.
Sol 930: Spirit took a tau measurement, an observation during which the rover evaluates atmospheric opacity to estimate dust height.
Sol 931: Spirit took pictures with the panoramic camera of targets named "Korolev" and "McMurdo grout 10." Spirit also used the panoramic camera to take a tau measurement.
Sol 932 (Aug. 17, 2006): Spirit took a tau measurement with the panoramic camera, surveyed the sky and ground with the miniature thermal emission spectrometer, and took