So Far, So Good In Returning Observatory To Functional Status

NASA reports that Wednesday night, Space Telescope Operations Control Center engineers at NASA's Goddard Space Flight Center turned on and checked out Side 'B' of Hubble's Science Instrument Control and Data Handling (SIC&DH) system... powering up a backup system the space agency hopes will return the orbiting observatory to near-full functionality.

As ANN reported, a transmission channel failed September 27 on Hubble's Control Unit/Science Data Formatter, one of many such systems used to relay data from Hubble to the ground, where it is assembled into images. That caused the telescope to revert to a safe mode... stopping all further data collection, until a little-used backup system could be made ready.

The fault also resulted in NASA postponing a planned shuttle flight to service the telescope, which was scheduled to launch October 10.

NASA states that after the backup system was powered up Wednesday, the Advanced Camera for Surveys (ACS), Wide Field Planetary Camera 2 (WFPC2) and Near Infrared Camera and Multi-Object Spectrometer (NICMOS) instruments were retrieved from safe mode to establish that each has a working interface to the Side B SIC&DH. The instruments were then commanded back into safe mode, and will remain in that state until the SI C&DH begins issuing commands to them, which NASA expected to do late Thursday.

At around noon Thursday, NASA began transmitting commands to recover Hubble's science instruments from their safe modes. Internal exposures and calibrations of the telescope's science instruments will occur before midnight Thursday.

Scientists at the Space Telescope Science Institute in Baltimore should complete their review of the internal exposures by noon on Friday, October 17. This procedure involves collecting and comparing baseline exposures previously supported by Side A of the SI C&DH to new exposures supported by Side B.

This review will be one last check of the "transparency" of switching to the redundant spacecraft electronics the Hubble team activated on Wednesday. A full schedule of science observations with the WFPC2 camera, ACS' Solar Blind Channel camera, and the Fine Guidance Sensors will resume early Friday morning... after which time NASA hopes to report Hubble is operational once again.

FMI: www.nasa.gov/hubble