Hubble Space Telescope: Eye wide open.The world's most prominent stargazer stargazer, common name for any of several species of marine fishes of the family Uranoscopidae, found in southern waters, and having the mouth, nostrils, and eyes set high in the head. Stargazers lie buried in the sand, waiting for their prey of small crustaceans. is back in business. Two months after a fourth gyroscope gyroscope (jī`rəskōp'), symmetrical mass, usually a wheel, mounted so that it can spin about an axis in any direction. When spinning, the gyroscope has special properties. failure robbed the Hubble Space Telescope Hubble Space Telescope (HST), the first large optical orbiting observatory. Built from 1978 to 1990 at a cost of $1.5 billion, the HST (named for astronomer E. P. Hubble) was expected to provide the clearest view yet obtained of the universe. of its cosmic view Cosmic View is an essay by Kees Boeke that combines writing and graphics to explore many levels of size and structure, from the astronomically vast to the atomically tiny. (SN: 11/27/99, p. 341), the $1.5 billion observatory has resumed operations, NASA NASA: see National Aeronautics and Space Administration. NASA in full National Aeronautics and Space Administration Independent U.S. announced last week. During a 9-day repair mission late in December, shuttle astronauts replaced the telescope's six gyroscopes and installed a 486-microprocessor computer--primitive by earthly standards but of proven reliability in the harsh environment of space. They also added new battery components and a solid-state tape recorder and upgraded the telescope's guidance system. The crew worked in pairs during three space walks, with day passing into night and back into day every 97 minutes. One astronaut's foot remained strapped to the shuttle's grappling arm while the other astronaut floated inside the telescope. Delayed 12 times due to faulty wiring and other problems with the shuttle fleet, the mission finally took off on Dec. 19. That was the last day in 1999 that NASA said it could send up the shuttle without fear of running into a Y2K See Y2K problem and Y2K compliant. Y2K - Year 2000 computer problem. Since last January, Hubble had been operating with just three gyroscopes, the minimum required to accurately point the telescope. That dicey situation had prompted NASA to propose a repair mission for last October. On Nov. 13, a fourth gyroscope failed, leaving Hubble too jittery to make observations. To save time, NASA relied on the same navigation software on the shuttle that it had used for a 1997 Hubble repair flight. It was Y2K certified just before the launch. As it was, NASA eliminated a fourth space walk to ensure that the U.S.-European crew returned to Earth on Dec. 27, in time to power down shuttle and ground software before the New Year. That meant that the crew put protective sheets of insulation over fewer electronic instruments than they had intended and abandoned plans to cover cracks in Hubble's skin with a wallpaperlike fabric. Those tasks will have to wait until the next servicing mission, now scheduled for 2001, says Hubble senior project scientist David S. Leckrone of NASA's Goddard Space Flight Center The Goddard Space Flight Center (GSFC) is a major NASA space research laboratory established on May 1, 1959 as NASA's first space flight center. GSFC employs approximately 10,000 civil servants and contractors, and is located approximately 6.5 miles northeast of Washington, D.C. in Greenbelt, Md. During that mission, astronauts plan to replace Hubble's wide-field and planetary camera with an advanced survey camera and install a new cooling system to revive the near-infrared camera that failed a year ago. |
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