Space shuttle Atlantis prepares for Friday landing

Posted by Aharon Etengoff

Chicago (IL) - The crew of the space shuttle Atlantis is preparing to return to Earth after successfully repairing and upgrading the Hubble telescope. Astronauts have reportedly tested the shuttle's reaction control system steering thrusters, which will be used to control Atlantis' altitude and speed after Friday's deorbit burn.

Crew members have also tested various shuttle aerosurfaces and flight control systems that will be activated once Atlantis enters Earth's atmosphere.

STS-125 is currently scheduled to land on Friday (10:00:31 a.m. EDT) at Kennedy Space Center. However, NASA flight directors are prepared to ctivate a backup landing site at California's Edwards Air Force Base in case of inclement weather. After touchdown, the astronauts will undergo physical examinations and meet with their families.

The Hubble Space Telescope was placed into orbit by the Space Shuttle Discovery in April 1990. Since then, the telescope has undergone five servicing missions to repair various systems and flaws. The ST-125 crew completed five lengthy spacewalks to upgrade a number of items, including thermal blankets, gyroscopes, batteries, cameras and subsystems.

Hubble is expected to operate until at least 2014, when its successor, the James Webb Space Telescope (JWST) is due to be launched. JWST is an "international collaboration" between NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA).

Northrop Grumman Space Technologies is currently the prime contractor for the telescope. The company has already completed a preliminary design review of its sunshield membrane management subsystem, which will protect JWST from high temperatures by blocking harsh solar light.

"The sunshield is designed to block solar light and keep the observatory operating at cryogenic temperatures. The [shield] will help enable the Webb Telescope's infrared sensors to see distant galaxies, early stars and planetary systems, and help astronomers better understand dark matter," explained Northrop spokesperson Sally Koris. "It's a five-layer sunshield that consists of extremely thin membranes and a supporting structure composed of spreader bars and a large composite shell. The JWST sunshield will block the sun with a giant beach-umbrella-like sunshield the size of a tennis court. If you could imagine, this would be like an SPF of 1.2 million."

Northrop has also supplied a cryocooler for Japan's Greenhouse Gases Observing Satellite (GOSAT), which was recently launched to study the negative affects of global warming. Similar, high temperature cryocoolers were manufactured for the Geostationary Operational Environmental Satellite-R Series (GOES-R).

A number of future science missions are likely to benefit from cryocooler technology advancements, including the Single Aperture Far-Infrared Observatory, (SAFIR) and the Terrestrial Planet Finder (TPF).

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