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Hubble Space Telescope Begins Shift From Stricken Unit To Backup System, But Further Glitches Force Shutdown

By | October 20, 2008

      NASA faces increasing chances that it will lose priceless scientific data and discoveries that it otherwise could have gathered during a third of a year, because a glitch on Sept. 27 struck a data formatter unit on the Hubble Space Telescope, and then an attempt to switch to a backup unit failed as other glitches arose.

      This left NASA having to halt all science observations on Hubble except for astrometry with the Fine Guidance Sensors.

      Experts controlling the Hubble last week attempted to work around the failed Side A science data formatter on the Hubble by switching to Side B.

      While at first the work seemed to progress well, with some systems coming up and running linked to Side B, then another problem occurred.

      These efforts involved the Hubble data management system and five components in the science instrument command and data handling system.

      The Wide Field Planetary Camera 2 switched to Side B, and so did the Near Infrared Camaera and Multi Object Spectrometer. So far so good, and NASA resumed the science timeline Thursday, with units awakening from their safe mode to operating modes.

      Then personnel attempted to switch over the Advanced Camera for Surveys (ACS), and the attempt went well until it was almost complete, when another glitch occurred.

      As the low voltage power supply to the ACS solar blind channel was commanded on, software running in a microprocessor in ACS detected an incorrect voltage level in the channel and suspended ACS.

      Then the Hubble spacecraft computer sensed the loss of a "keep alive" signal from an onboard computer and correctly responded by placing the systems back in safe mode. It is not yet known if these two events were related.

      The investigation into both anomalies is underway. All data has been collected and is being analyzed. The science instruments will remain in safe mode until the issue is resolved. All other subsystems on the spacecraft are performing nominally and astrometry observations continue.

      When the Side A unit failed Sept. 27, NASA faced the bleak prospect of losing an immense amount of data that Hubble otherwise could gather until — sometime in February — Space Shuttle Atlantis rides to the rescue with a replacement unit.

      Atlantis crew members also will perform a major repair and refurbishment overhaul on Hubble, a mission that was poised to take off last week until the Hubble glitch forced NASA to postpone liftoff for four months.

      This may mean that Hubble won’t be able to resume probing the secrets of the universe for a third of a year. Discoveries beamed down from the orbiting space observatory have gone back to just after the Big Bang when the known universe was created. Further, Hubble pictures of supernovas were captured, along with the sights of dying, colliding and newly born stars, subatomic particles streaking in a jet emerging from a black hole, and much more

      To say that the Hubble has made a gigantic contribution to astronomy is gross understatement. Since its launch in 1990, it has amazed astronomers with its unprecedented insights into the heavens.

      Hubble began its life aloft inauspiciously, with a design flaw in a mirror that meant the multi-billion-dollar space telescope at first couldn’t focus well, igniting a firestorm of criticism from the scientific community and from lawmakers such as Sen. Al Gore (D-Tenn.), who later became vice president.

      That shortcoming was fixed, however, in a refurbishment mission similar to the impending Space Shuttle Atlantis trip to upgrade the Hubble.

      Since then, the space telescope has performed brilliantly, so that many lawmakers and astronomers were appalled that the Hubble might be allowed to fade into an early death.

      A drive began to rescue the Hubble and extend its life to 2013 (when it will be replaced by the next-generation James Webb Space telescope).

      Leading the years-long and ultimately successful charge to fund a refurbishment and rescue mission for Hubble were Sen. Barbara A. Mikulski (D), who chairs the Senate Appropriations Committee commerce, justice, science and related agencies subcommittee that has jurisdiction over NASA programs. The Goddard Space Flight Center, which operates the Hubble, is in her state, Maryland.

      With funding in hand for the Hubble fix, the Atlantis STS-125 Mission to renovate the Hubble was to have lifted off last week until the Side A glitch occurred, forcing NASA to delay the Atlantis trip until sometime in February.

      When complete, Hubble will be better than ever for its final years in orbit, a telescope scanning the universe from a high vantage point far beyond the distortion, pollution, and distracting lights in the atmosphere of planet Earth.

      The down side of all this is that the Atlantis mission is delayed, and NASA — never an agency flush with money — will have to spend millions of dollars for every month it is postponed.

      But the upside is that the Side A glitch occurred before Atlantis lifted off, so it can replace the dead unit and permit Hubble to fulfill its brilliant promise until the James Webb Space Telescope is lofted into orbit no earlier than 2013.

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