1245p 10/17 Update: Hubble reboot problems; troubleshooting

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CBS NEWS Coverage of Breaking Space News
Posted: 12:45 PM, 10/17/08

By William Harwood
CBS News Space Consultant

Changes and additions:

10/14/08 (05:25 AM): Soyuz TMA-13 docks with international space station
10/14/08 (06:30 AM): Hatches opened; Soyuz crew enters space station
10/14/08 (03:35 PM): Engineers gear up for critical commanding to switch Hubble to backup electronics
10/17/08 (12:45 PM): Initial Hubble reboot goes smoothly but anomalies interrupt reactivation

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12:45 PM, 10/17/08, Update: Initial Hubble reboot goes smoothly but anomalies interrupt reactivation

Work to switch the Hubble Space Telescope to a backup data management system after a component failed last month has been interrupted by a pair of anomalies that require additional troubleshooting, NASA officials said Friday.

"Activation of the Hubble Space Telescope science instruments and resumption of science observations have been suspended following two anomalies seen in systems onboard the telescope on Thursday," NASA said in an 11 a.m. internet statement. "All of the telescope's payloads are back in safe mode condition while engineers perform troubleshooting. An updated status report with more information will be issued shortly."

The original failure occurred Sept. 27 as NASA was preparing to launch the shuttle Atlantis Oct. 14 on a long-awaited servicing mission. Channel A of the telescope's control unit science data formatter, or CU/SDF-A, began acting erratically and the telescope's flight computer, following pre-programmed instructions, "safed" the payload computer and science instruments.

An attempt by ground controllers to reset the formatter was not successful and engineers quickly determined the box had suffered a "hard" failure. With the formatter out of action, data from Hubble's operational science instruments could not be relayed to the ground.

The shuttle flight was delayed to mid February at the earliest to give engineers time to qualify a ground computer test unit for flight to restore channel A to normal operation. In the meantime, engineers at the Goddard Space Flight Center in Greenbelt, Md., decided to switch Hubble over to its B-side data management system to restore science operations. Those components have not been powered up since launch in 1990.

The switchover began Wednesday. Telemetry from the telescope indicated the initial transition went smoothly and Hubble's 486 flight computer was reloaded. Wednesday night, engineers turned on the B-side science instrument control and data handling system, which includes the B-side data formatter. They then confirmed the Wide Field Planetary Camera 2, the one operational channel of the Advanced Camera for Surveys and the Near Infrared Camera and Multi-Object Spectrometer, or NICMOS, were able to communicate with the B-side SI C&DH system. The instruments then were put back in safe mode pending commands to switch control to the SI C&DH.

Thursday, engineers planned to bring the science instruments back on line to begin calibration and checkout.

"Scientists at the Space Telescope Science Institute in Baltimore should complete their review of the internal exposures by noon on Friday, October 17," NASA said in a statement Thursday. "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" (non-impact) 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," the statement said.

But two anomalies somewhere in that chain of activation and checkout apparently cropped up, forcing engineers to put the instruments back in safe mode pending additional troubleshooting. Todaty's initial statement did not provide any additional details. This status report will be updated when more information is available.

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Quick-Launch Web Links:

CBS News STS-126 Status Reports:
http://www.cbsnews.com/network/news/space/current.html

CBS News STS-126 Quick-Look Page:
http://www.cbsnews.com/network/news/space/currentglance.html

NASA ISS Expeditions Page:
http://www.nasa.gov/mission_pages/station/expeditions/index.html

NASA Shuttle Web: http://spaceflight.nasa.gov/shuttle/index.html
NASA Station Web: http://spaceflight.nasa.gov/station/index.html
Spaceflight Now: http://spaceflightnow.com/index.html
GoogleSatTrack: http://www.lizard-tail.com/isana/tracking/

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