This video presents an overview of the tasks to be performed during the mission to Hubble. Image Credit: NASA + View Video
Galaxies from the early universe. The birthplaces of planets. Dark matter. Dark energy. Since its launch in 1990, the Hubble Space Telescope has brought these mysteries into focus, its powerful gaze scanning the universe for the details planet-bound telescopes find impossible to detect.
Far above the Earth's surface, Hubble floats clear of the planet's light-distorting atmosphere, beaming back images that have transfixed humanity and changed the scientific world.
Hubble's triumphs continue to accumulate thanks to a unique design that allows astronauts to repair and upgrade the telescope while it remains in orbit. Repairs keep the telescope functioning smoothly, while upgrades to the instruments bring a slew of new discoveries and science.
Meet the crew that will give Hubble its extreme makeover. Image Credit: NASA
+ View Interactive
The next servicing mission, Servicing Mission 4 (SM4), in May 2009, will be the final trip to the Hubble Telescope. Over the course of five spacewalks, astronauts will install two new instruments, repair two inactive ones, and perform the component replacements that will keep the telescope functioning at least into 2014. The effort-intensive, rigorously researched, exhaustively tested mission also involves diverse groups of people on the ground throughout the country.
The mission's planning is years in the making, and its success will be the product of months of intensive preparation and the work of hundreds of people at NASA and in academia and industry.
Astronauts train at NASA's Johnson Space Center in Texas, where they learn to deal with weightlessness in a giant water tank in the Neutral Buoyancy Lab, and at Goddard Space Flight Center in Maryland, where they enter Goddard's huge intensively filtered "clean room" to work with the actual equipment they'll use and install aboard Hubble. Goddard prepares and tests instruments and hardware, while Kennedy Space Center in Florida prepares the space shuttle for the mission.
|Read these behind-the-scenes stories leading up to the mission|
+ Goddard Engineers and Divers Multi-Task for Hubble
+ NASA's Clean Room: Last Stop for New Hubble Hardware
+ NASA Goddard Provides Environmental Testing for Hubble Components
+ Hubble's In-Flight Guidance from the Ground
The Shuttle robotic arm captures the Hubble Telescope Image Credit: NASA
+ View Video During SM4, teams at Johnson and Goddard work around the clock to make sure the mission succeeds. Johnson's Mission Control Center monitors the space shuttle and astronauts, and supervises spacewalks, procedures, crew activities and health, as well as shuttle systems and experiments. Hubble personnel, including managers, scientists, and engineers from Goddard and the Space Telescope Science Institute in Maryland, will be split between supporting the mission at Johnson and those working at Goddard.
At Goddard, where the Hubble program is administered, the Space Telescope Operations Control Center controls the telescope itself, giving the commands that prepare the telescope for the astronauts' activities and test the newly installed equipment. Goddard's Control Center closes the door that protects the telescope's delicate optics, and maneuvers Hubble into position as the shuttle Atlantis approaches.
When the shuttle is about 200 feet (60 m) away from Hubble, Goddard will command the telescope to execute a roll that brings it into position for grappling. Astronauts use the shuttle's robotic arm to capture Hubble and dock it in the shuttle's cargo bay.
A team of astronauts perform upgrades on the telescope during a spacewalk in the 2002 servicing mission. One astronaut uses a handrail (left) to hold onto Hubble while the other is attached to the shuttle's robotic arm by a foot restraint (right) Image Credit: NASA
> View Larger Image Next, the astronauts begin their series of five six-and-a-half-hour spacewalks. Two astronauts work outside on Hubble at a time. One mainly handles the free-floating tasks. The other is connected by a foot restraint to the robotic arm, which is operated by a third astronaut from within the shuttle. To keep themselves from accidentally floating away, the astronauts attach safety tethers to a cable that runs along the cargo bay. Hubble was built with handrails that also make it easy for astronauts to cling to the telescope.
Out With the Old
Many of the telescope's components, especially the instruments, were designed to be easily removed and replaced during servicing missions. This mission's primary scientific priority is the installation of Hubble's new instruments, Wide Field Camera 3 (WFC3) and the Cosmic Origins Spectrograph (COS).
Wide Field Camera 3 will be the power behind studies of dark energy and dark matter, the formation of individual stars and the discovery of extremely remote galaxies previously beyond Hubble's vision. WFC3 sees three different kinds of light: near-ultraviolet, visible and near-infrared, though not simultaneously. The camera's range is much greater than that of the instruments currently aboard.
COS (black box) sits in its protective carrier waiting for delivery to the Hubble Telescope. This same carrier will protect COSTAR on its trip back to Earth at the end of the mission. Image Credit: NASA
> View Larger Image Astronauts will remove Hubble's Wide Field and Planetary Camera 2 (WFPC2) to make room for WFC3. WFC3 has a higher "resolution," or ability to distinguish details, and a larger "field of view," or area the camera is able to see, than WFPC2.
Galaxy evolution, the formation of planets, the rise of the elements needed for life, and the "cosmic web" of gas between galaxies will be some of the areas of study for the Cosmic Origins Spectrograph (COS). A spectrograph is an instrument that breaks light into its component colors, revealing information about the object emitting the light. COS sees exclusively in ultraviolet light and will improve Hubble's ultraviolet sensitivity at least 10 times, and up to 70 times when observing extremely faint objects.
COS will take the place of the device installed in Hubble during the first servicing mission to correct Hubble's flawed mirror, the Corrective Optics Space Telescope Axial Replacement (COSTAR). Since the first servicing mission, all of Hubble's replacement instruments have had technology built in to them to correct Hubble's marred vision, making COSTAR no longer necessary.
|Get the facts behind the instruments. Read these related Fact Sheets:|
+ Advanced Camera for Surveys Repair
+ Space Telescope Imaging Spectrograph Repair
+ Wide Field Camera 3
+ Cosmic Origins Spectrograph
Behind a pair of aft shroud doors, Hubble's six gyroscopes are found within 3 rate sensor units (circled in image). Image Credit: NASA > View Larger Image
The telescope's six gyroscopes are part of the system that points the telescope. When all six gyroscopes are functioning, three gyroscopes are used for pointing, and the other three are held in reserve. Time has degraded the gyroscopes to the point where three have failed, two are in use, and a third is turned off to be used as an emergency backup. Astronauts will install six new gyroscopes.
Hubble's Fine Guidance Sensors (FGS) lock onto guide stars, helping the telescope point. They can also be used as instruments to measure the position of stars in relation to other stars. Astronauts will replace one worn-out FGS with a refurbished model that was removed during a previous servicing mission.
Hubble's insulating blankets, which maintain the telescope's normal operating temperature, eventually break down because of their exposure to space. Astronauts will cover key Hubble equipment bays in fresh insulation, also called a New Outer Blanket Layer (NOBL).
Finally, they will install a new device, the "soft capture mechanism." This simple device will allow a robotic spacecraft to attach itself to Hubble someday, once the telescope is at the end of its life.
|Get the facts behind the maintenance activities. Read these related Fact Sheets:|
+ Fine Guidance Sensor
+ New Outer Blanket Layer
+ Soft Capture and Rendezvous System