Hubble revives

Switch to a backup system is successful

11:13am, October 16, 2008
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NASA engineers late on October 15 successfully rebooted the Hubble Space Telescope, which has been silent since September 27, when a unit that formats data so it can be relayed to Earth suddenly failed.

Engineers were able to switch Hubble from the failed unit to a duplicate device, officially known as the science instrument control and data handling system, which is still operating on the 18-year-old spacecraft.

The engineers then briefly switched back on several of Hubble’s instruments — the Advanced Camera for Surveys, the Wide Field Planetary Camera 2 and the Near Infrared Camera and Multi-Object Spectrometer — to ensure that each had a working interface with the duplicate unit. The instruments were then commanded back into a dormant “safe mode," in which they were hibernating since the observatory went silent.

Starting around noon October 16, engineers are scheduled to begin relaying commands to revive some of the science instruments out of their hibernation. Testing and calibration of the devices should occur before midnight.

Scientists at the Space Telescope Science Institute in Baltimore are aiming to complete a final review of the health of the science instruments by noon on October 17. Still, Hubble will not have its full complement of instruments operating. Most observations with the Advanced Camera for Surveys haven’t been possible since a short circuit that developed early last year.

In addition, because of a more recent glitch, the Near Infrared Camera and Multi-Object Spectrometer will not be immediately operating and NASA might not attempt to revive it until a shuttle servicing mission that has been delayed until February, a spokeswoman at the Space Telescope Science Institute said.

Thus, when the science instruments are revived, the Wide Field Planetary Camera 2 and Hubble’s Fine Guidance Sensors, which allow astronomers to track the motion of stars, will be the only instruments functioning at full capacity.

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