Major Failure On the Hubble Space Telescope; Repair Mission Options Being Weighed

A major failure on the Hubble Space Telescope has shut down science operations, as the spacecraft is unable to send any data to Earth, according to an article on NASA Spaceflight.com. The failure is on the “Side A” control system. There is also a back-up system, Side B which has never been used. Attempts will be made to switch to Side B later this week. This switch has never been attempted during the lifetime of the telescope, but it is hoped that the switch will work, allowing the HST to return to functionality. This may have an impact on the STS-125’s mission to repair the Hubble, delaying it to 2009, if managers decide to send up a replacement unit, or if a mitigation plan fails to restore the Telescope’s functionality.

Update: NASA held a news conference this afternoon, and said the servicing mission — which was going to launch on Oct. 14 — is definitely on hold. They will attempt to turn on Side B later this week, and depending on how that goes, they are working on a plan to have the shuttle servicing mission bring up and install a spare Science Instrument Command and Data Handling System sometime in 2009. Phil has the dicey details over at Bad Astronomy

Information obtained by NASA Spaceflight.com reads as follows:

“Side A of the CUSDF (Control Unit/Science Data Formatter) in HST went into safe hold, this means science operations have stopped. The spacecraft is still operational but unable to operate the instruments,” noted information acquired by L2.

“Attempts to recover the A side have failed so the project is now working to transfer science operations to the B side, this requires transferring the whole spacecraft from Side A to Side B so its a significant operation.

“Side B side has not been operated on orbit, for HST’s entire on orbit service life it has operated on Side A. However, the B side was fully tested before launch.

“The plan as of now is to complete the transfer to the B side later this week. The details for this will be provided later by the project.

“If the B side comes up fine we could still launch on time so I propose that we do not postpone the (Agency) FRR (Flight Readiness Review) at this time.

“If the B side does not come on line then we clearly have no mission as there is no way to get science data down. ”

“Options are in work. Earlier we had a plan to launch STS-126 first in November and follow up with HST in Feb. with the Feb. 2009 flight as back-up,” says a memo obtained by NASA Spaceflight.com

Stay tuned.

Source: NASA Spaceflight com