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SPACE FLIGHT 2001 -- United States Space Activities

Launch activities in the United States in 2001 showed a distinct downturn from the previous year. There were 24 NASA, DOD, and commercial launch attempts and 23 successful launches (2000: 31 out of 31).

Space shuttle. The four reusable shuttle vehicles of the U.S. Space Transportation System (STS) continued carrying people and payloads to and from Earth orbit. During 2001, six shuttle mission were conducted in 2001, one more than in 2000, all for supply, logistics, outfitting, crew rotation and orbital assembly of the ISS. For the human space flight program, the year was particularly significant in that three of the shuttle missions involved crew rotation, i.e., replacement of resident crews on the ISS.

Advanced transportation systems activities. In the five-year-old NASA/industry cooperative effort to develop a reusable space launch vehicle (RLV) to eventually take over launchings for a fraction of today's cost of space transportation, 2001 brought some changes. On March 1, NASA announced that the X-33 and X-34 projects would not receive additional government funding, effectively ending these cooperative efforts with private industry to demonstrate in suborbital flight the technologies needed for an RLV. At the same time, NASA announced a new 5-year project, the Space Launch Initiative (SLI), also called the second-generation RLV program. On May 17, NASA awarded 22 contracts for developing the technologies that will be used to build an operational RLV before 2015.

NASA's Hyper-X program suffered a setback in 2001 when the first of three planned X-43 hypersonic test flights, the X-43A, ended in the intentional destruction of the research vehicle after its Pegasus booster rocket, used to accelerate the demonstrator to Mach 7 at 95,000 ft, went out of control early in the flight. The 12-ft. (3.6 m)-long, unpiloted, non-rocket-propelled X-43 vehicles, airlaunched from a B-52 airplane, are powered by supersonic combustion ramjets ("scramjets") on hydrogen fuel, after acceleration by the booster. The X43C follow-on program continues. Slightly larger than X-43A, the X-43C will use flight-weight versions of the Air Force HyTech hydrocarbon scramjet engine, rocket-boosted to Mach 4 and then accelerating on its own power to Mach 7. The third demonstrator, the reusable X-43B, will be next, and it will be able to land on a runway after its Mach 7 flight following the B-52 air launch.

NASA is participating in an Air-Force-led activity under a new National Hypersonic S&T Plan, formulated by the Office of the Secretary of Defense, to spearhead a much more focused government/industry effort to develop hypersonic technologies, which, among else, could enable new space transportation for NASA.

Specifically for the ISS, NASA continued work on a Crew Return Vehicle (CRV) to eventually take over the emergency lifeboat function for the space station from the currently chosen Russian Soyuz three-seater capsules. CRV could provide a shirtsleeve environment for seven crewmembers in reclined couches, standard-sized for 95% of all U.S. males. In 2001, NASA continued with full-scale flight testing of the X-38, the prototype test vehicle for the CRV, by dropping it from a B-52 and landing it under a large parafoil. (In 2002, NASA terminated the X-38 effort).

Space sciences and astronomy. In 2001, the U.S. launched six civil science spacecraft, up four from the previous year. Since 1995 NASA has markedly increased the number of civil satellites it develops and launches due to the switch in development strategy, shortly after the loss in August 1993 of the Mars Observer, from large, expensive satellites to smaller and more numerous ones.

Hubble Space Telescope. Eleven years after it was placed in orbit, the Hubble Space Telescope (HST) continued to probe far beyond the Solar System, producing imagery and data useful across a range of astronomical disciplines. Hubble was and is making discoveries at a rate that is unprecedented for a single observatory, and its contributions to astronomy and cosmology are wide-ranging. In 2001, astronomers using the HST measured the atmosphere of a planet outside our solar system. Eight new extrasolar planets were discovered that have circular orbits, similar to the orbits of planets in our own solar system.

Chandra Observatory. Launched on July 23, 1999, on shuttle mission STS-93, the massive (12,930 lbs./5,870 kg) Chandra X-ray Observatory uses a high-resolution camera, high-resolution mirrors and a charge-coupled detector (CCD) imaging spectrometer to observe, via X-rays, some of the most violent phenomena in the universe which cannot be seen by the Hubble's visual-range telescope. Throughout its second year of operation, Chandra continued to provide scientists with views of the high-energy universe never seen before which promise to revolutionize astronomical and cosmological concepts. From the images, spectra and lightcurves created from Chandra's data streams, researchers have accumulated an impressive list of scientific firsts, including a flare from a brown dwarf star and possibly iron-line emissions in the X-ray afterglow of a gamma-ray burst. A number of technical problems had to be overcome, and thanks to the robust design of the observatory, their impact on its performance has been minimal. In a symposium on "Two Years of Science with Chandra" on September 5-7, 2001, Chandra's contributions to virtually every astrophysics topic were presented, including stellar coronae, star formation, compact objects, black holes, quasars, supernova remnants, clusters of galaxies, solar system objects and the resolution of the long-standing mystery of the origin of the celestial X-ray background. In September 2001, NASA formally extended the operational mission of Chandra from 5 years to 10 years, including the science grants that fund astronomers to analyze their data and publish their results.

Galileo. In 2001, Galileo continued to return unprecedented data on Jupiter and its satellites, particularly on its bizarre moon Io. High-resolution images taken during several close passages of this intriguing moon by the spacecraft are aiding analysis of the connection between volcanism and the rise and fall of mountains on Io. Few of Io's volcanoes resemble the crater-topped volcanic peaks seen on Earth and Mars; they are in relatively flat regions, not near mountains, but nearly half of the mountains on Io sit right beside volcanic craters. By the end of its observations of Io in early 2002, the spacecraft had discovered 74 of the 120 known Ionian hot spots, and the data help scientists develop an understanding of how that distant world resurfaces itself differently that our world does. Another important discovery of Galileo was been the likelihood of a melted saltwater ocean under the moon Europa's icy crust, making it of great interest for future study of the possibility of extraterrestrial life. Galileo was launched by Shuttle mission STS-34/Atlantis on October 18, 1989. After a six-year journey to Jupiter, the spacecraft began orbiting the huge planet on December 7, 1995, and successfully completed its two-year primary mission in 1997. NASA has since extended its original two-year mission three times. By end-2001, Galileo was nearly out of the hydrazine propellant needed to keep its antenna pointed toward Earth and do maneuvers. Plans are for it to make its last flyby of a Jupiter moon in November 2002, when it passes close by Amalthea, then loop one last time away from Jupiter and finally perish in a fiery plunge into Jupiter's atmosphere in Dseptember 2003, to ensure that there is no chance the long-lived spacecraft might hit (and possibly contaminate) Europa.

Cassini. NASA's six-ton spacecraft Cassini continued its epic 6.7-year, 3.2-billion-km journey to the planet Saturn. During a final flyby with Jupiter on December 30, 2000, which boosted its velocity by 2.2 km/sec (5000 mph), Cassini collected data on the giant planet, for example, capturing bright auroras on Jupiter and its moon Io, and taking measurements on Jupiter's magnetosphere, which showed that the ionized-gas bubble encasing the planet is lopsided and leaky, with an unexpected abundance of high-energy particles bleeding out of one side, perhaps riding magnetic field lines attached to Jupiter at one end and waving loose on the other. Its readings also indicate that radiation belts very close to Jupiter would damage any future spacecraft there even more severely than previously estimated. The harshest radiation occurs within about 300,000 km (about 200,000 miles) of the giant planet, closer than the closest passages of the Galileo orbiter, and a safe 300 times closer than Cassini's flyby. By end of 2001, the spacecraft continued to fly in excellent health, with 30 months to go before it becomes the first Earth envoy to enter orbit around the ringed planet Saturn, on July 1, 2004. About six months after orbit insertion, it will release its piggybacked European-built Huygens probe for descent through the thick atmosphere of the moon Titan on January 14, 2005.

DS-1. NASA's Deep Space 1 (DS-1) technology test satellite was launched on October 24, 1998. During a highly successful primary one-year mission, it tested 12 advanced, high-risk technologies in space, including low-thrust xenon ion propulsion. Its mission was extended another two years, and on July 28, 1999, the DS 1 spacecraft flew past asteroid 9969/Braille. Camera problems limited the data received during this encounter. When the star tracker, used to navigate the spacecraft, became inoperable, the imaging camera was programmed to carry out the necessary navigation functions. On September 22, 2001, it flew a close encounter of Comet 19P/Borelly, coming within 2171 km (1357 mi.) of the asteroid's solid core and returning the best images and other science data ever received from a comet. During its fully successful hyperextended mission, DS 1 conducted further technology tests, until it was retired on December 18, 2001. Its ion propulsion system has provided the equivalent of about 4.2 km/sec (9400 miles/hr) velocity change to the spacecraft while consuming less than 70 kg (157 lbs) of xenon propellant. The system has accumulated more than 640 days of thrust time.

MAP. NASA's Microwave Anisotropy Mission (MAP) was launched on June 30 on a Delta-2. After executing several highly elliptical phasing orbits, MAP flew by the Moon, getting a gravitational "assist" to boost it to the second Lagrange libration point L2, from where its differential radiometers measure the temperature fluctuations of the cosmic microwave background radiation, with much higher resolution, sensitivity, and accuracy than the earlier Cosmic Background Explorer spacecraft launched in 1989.

Genesis. The solar probe Genesis was launched on August 8, 2001, on a Delta 2 rocket and went into perfect orbit about the first Earth-Sun Lagrangian libration point L1 on November 16. After the unconventional "Lissajous Orbit Insertion" (LOI), Genesis began five "halo" loops around L1, lasting about 30 months. Science collection started officially on November 30, 2001, when the spacecraft opened its science canister. On December 3, it extended its collector arrays to catch atoms from the solar wind. After 29 months in orbit, the sample collectors will be re-stowed and returned to Earth, where the sample return capsule will be recovered in mid-air by helicopter over the Utah desert in September 2004.

ACE & Wind. The Advanced Composition Explorer (ACE) was launched on August 25, 1997, to the libration point L1. Positioned in a halo orbit around L1, where gravitational forces are in equilibrium, ACE in 2001 continued to observe, determine and compare the isotopic and elemental composition of several distinct samples of matter, including the solar corona, the interplanetary medium, the local interstellar medium and galactic matter. Wind, launched on November 1, 1994, as part of the International Solar-Terrestrial Project (ISTP), was first placed in a sunward, multiple double-lunar swingby orbit with a maximum apogee of 350 Earth radii, followed by a halo orbit at the L1 point. Science objectives include measurements for magnetospheric and ionospheric studies, plasma processes occurring in the near-Earth solar wind, and comparison observations in the ecliptic plane for Ulysses.

Stardust. NASA's comet probe Stardust was launched on Februsary 3, 1999 on a Delta 2 to begin its mission to intercept a comet and return close-up imagery to Earth. Also, for the first time ever, comet dust and interstellar dust particles will be collected during a close encounter with Comet Wild-2 in 2004 and returned to Earth for analysis. Stardust's trajectory is making three loops around the Sun before its closest approach to the comet in January 2004. All the collected samples, captured in an aerogel collector, will be retracted into a sample return capsule, which then will be returned to Earth via parachute for a soft landing at the U.S. Air Force's Utah Test and Training Range in 2006.

NEAR-Shoemaker. Launched on February 17, 1996, the Near Earth Asteroid Rendezvous (NEAR) Shoemaker spacecraft entered orbit around the asteroid 433 Eros on February 14, 2000 (after a failure of the first of several rendezvous maneuvers on December 20, 1998, had changed plans), beginning its year-long orbit of the asteroid to determine its mass, structure, geology, composition, gravity, and magnetic field. In 2001, NEAR-Shoemaker added to its list of accomplishments by becoming the first spacecraft to land on an asteroid. On February 12, the spacecraft was gradually lowered from its 35-km (21.8 mi.) orbit until it touched down on the surface of Eros. Although designed as a purely orbiting mission, NEAR-Shoemaker survived the landing and continued operations on the asteroid until it was shut down on February 28.

Ulysses. With the European-built spacecraft and its scientific payload in excellent condition, in the middle of its current mission phase of studying the Sun's polar regions under conditions of high solar activity. Ulysses ended its South polar pass of the Sun on January 16, 2001, crossed the ecliptic on May 25 and started the second North polar pass on August 31. After reaching its maximum North solar latitude of 80.2 degrees on October 13, it ended the second North polar pass on December 10. Ulysses' signals are transmitted to its operations center at NASA's Jet Propulsion Laboratory in Pasadena, California.

Mars exploration. After the stunning failures of two Mars probes in 1999, NASA's Mars exploration program rebounded in 2001. The Red Planet moved back into the focus of scientific inquiry, with new discoveries on the turbulent past of the planet's surface and atmosphere.

Mars Odyssey. The 2001 Mars Odyssey probe was launched on April 7 and successfully reached Mars after a six-month and 286-million mile journey on October 24. Entering a highly elliptical orbit around the poles of the Red Planet, it began to change orbit parameters by aerobraking, reduce its ellipticity to become a circular orbit at 400 km by end of January 2002. The orbiter will circle Mars for at least three years, with the objective of conducting a detailed mineralogical analysis of the planet's surface from space and measuring the radiation environment. The mission has as its primary science goals to gather data to help determine whether the environment of Mars was ever conducive to life, to characterize the climate and geology of the planet, and to study potential radiation hazards to possible future astronaut missions. The orbiter will also act as a communications relay for future missions to Mars over a period of five years.

Mars Global Surveyor (MGS). MGS completed its primary mission at the end of January 2001 and entered an extended mission. The spacecraft has returned more data about the Red Planet than all other missions combined. After its arrival at Mars on September 11, 1997, MGS started a long series of aerobrake passes around the planet and, after reaching its operational orbit early in 1999, began its mapping mission on March 9. For the first three weeks, the mission proceeded with the spacecraft's 1.5-m (5 ft) high-gain antenna stowed due to concerns about the proper operation of its deployment mechanism. On March 28, 1999, the antenna was successfully deployed. Since then, MGS has been transmitting a steady stream of high-resolution images of Mars, which showed that the Red Planet is a world constantly being reshaped by forces of nature including shifting sand dunes, monster dust devils, wind storms, frosts and polar ice caps that grow and retreat with the seasons. In 2001, it sent back its 100,000th image of the Martian surface and, in tandem with the Hubble Space Telescope, had a ringside seat to the largest global dust storm on the Martian surface seen in decades.

Pioneer 10. Launched from Cape Kennedy in 1972 aboard an Atlas/Centaur on a mission to Jupiter planned for only two years, the 570-lbs. (258-kg) Pioneer 10 became the Earth's longest-lived interplanetary explorer, as it continues on its epic voyage to the stars as contact with it is still maintained by NASA's Deep Space Network. Currently at a distance of 12.19 billion kilometers (7.57 billion miles) from Earth, Pioneer 10 is passing through the transitional region between the farthest traces of the Sun's atmosphere, the heliosphere, still noticeable at that distance, and free intergalactic space. Signals transmitted by the little spacecraft today need 11 hours 17 minutes to reach Earth. Its course is pointed in the direction of the star Aldebaran, the "eye" of the constellation Taurus at a distance of 68 light-years (LY), which it will reach in two million years. But before that, at its current speed of 45,000 km/h (28,000 mph) the spacecraft will pass the red dwarf Proxima Centauri in 26,118 years, come within 3.2 LY of the red dwarf star Ross-248 in the Andromeda Nebula in 32,605 years, and fly by the white giant star Altair in 227,068 years. On April 28, 2001, a signal was received from Pioneer 10, the first time since August 5/6, 2000, and it appears that the spacecraft now transmits only when contacted (i.e., two-way coherent mode), requiring 22 hrs 35 min of ground antenna time. On July 9, 2001, exactly one year after the last antenna pointing maneuver, radio data from Pioneer 10 indicated that the maneuver had indeed been successful, and another pointing maneuver was not necessary until the first quarter 2002.

Earth Science. In 2001, NASA announced the creation of the first complete "biological record of Earth" by using data from NASA's Sea-viewing Wide Field-of-View (Sea-WIF) sensor. Researchers also suggested the Earth is becoming a greener greenhouse, determining that plant life in the northern latitudes has been growing more vigorously since 1981. In February 2001, NASA released a new map of Antarctica made from Radarsat data. Using the new maps and comparing them to maps produced in 1981, scientists will track Antarctic ice changes, a key to understanding our global environment and climate change. In 2001, NASA research also suggested that desert dust in the atmosphere over Africa might actually inhibit rainfall in the region, contributing to drought conditions.

Department of Defense space activities. United States military space organizations continued their efforts to make space a routine part of military operations across all service lines. One focus concerns plans for shifting the advanced technology base toward space in order to build a new technology foundation for more integrated air and space operations in the 21st century as space is becoming increasingly dominant in military reconnaissance, communications, warning, navigation, missile defense and weather-related areas. The distinction between space and missile activities is becoming increasingly theoretical, as evidenced by missile interception tests made in 1999: a THAAD (Theater High-Altitude Area Defense) successfully intercepted a target missile outside the Earth's atmosphere on June 10 of that year. On December 4, 2001, a missile launched from the Marshall Islands successfully intercepted a Minuteman missile at 260 km altitude with an "Exoatmospheric Kill Vehicle", the third success in the context of the GDM (Ground-based Midcourse Defense).

In 2001, there were seven military space launches from Cape Canaveral, Florida, and Vandenberg Air Force Basae, California: two Delta 2 rockets, two Atlas 2AS rockets and three Titan 4B launch vehicles. Payloads included one GPS navigation satellite, two large comsats, one large imaging spacecraft, one missile warning satellite, and two recon satellites.

Commercial space activities. In 2001, commercial space activities in the United States encountered serious industry difficulties due to a crisis in the communications space market caused by failures of satellite constellations for mobile telephony. While two satellite mobile-phone projects, Iridium LLC and ICO Global Communications Ltd., had to file for Chapter 11 U.S. bankruptcy protection already late in 1999, Orbcomm Global LP followed the same route, and Globalstar LP also showed financial weakness. Skybridge announced in March 2001 that it would postpone its planned construction of an 80-satellites network. A similar downturn hit GEO (geosynchronous orbit) satellite enterpreneurs, like Astrolink (Lockheed Martin) and Spaceways (Hughes). In December 2001, Lockheed Martin Corp. announced that it would abandon its communications service activities.

In addition to the financial crisis, some difficulties remained due to the export restrictions imposed to the US industry on sensitive technologies. In general, commercial ventures continue to play a relatively minor role in US space activities, amounting in 2001 to about 50% of commercial satellites and associated launch services worlwide.

Of the 24 total launch attempts by the United States in 2001 (vs. 31 in 2000), seven carried commercial payloads (NASA: 10; military: seven), as in 2000, with one failure. In the launch services area, Boeing launched seven Delta-2 vehicles, followed by Lockheed Martin with four Atlas 2A. The failed launch was an Orbital Science Corp. (OSC) Taurus with commercial payloads. Both sea launches of the Zenit 3SL rocket from the Odyssey launch platform floating at the Equator were successful, operated by a partnership of Boeing, RSC-Energia (Russia), NPO Yushnoye (Ukraine) and Kvaerner Group (Norway).