New Problem Will Add New Tasks To Already Complicated Mission

NASA will delay its mission to the Hubble Space Telescope until next year, after the orbiting observatory suffered a failure of its command and data-handling system Saturday night.

The New York Times reports the problem lies with a transmission channel on the Hubble 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 channel failed, causing the telescope to revert to a safe mode... stopping all further data collection.

That failure has stopped the flow of Hubble's stunning deep-space images. While NASA hopes to have a backup channel up and running later this week, a permanent repair will require a new series of tasks for which the Atlantis crew has not been trained.

Early Monday afternoon, NASA announced that the launch has been moved from October 14 to sometime in 2009, possibly as early as February. The delay will be needed to test replacement parts, and train the crew for the installation.

The planned STS-125 mission was already one of the most complicated and potentially dangerous in the history of the shuttle program. The crew has already been training for two years to swap out worn circuit boards inside the telescope's Advanced Camera for Surveys and the Space Telescope Imaging Spectrograph. When Hubble was launched 18 years ago, designers didn't envision it remaining in use this long, and the circuits being replaced were not designed for replacement in orbit.

Fortunately, the repair itself may not be so complicated -- at least, relative to other tasks already on the STS-125 crew's massive "to-do" list. The faulty part is attached to the inside of a bay the astronauts will need to access anyway, and it's attached by just 10 bolts.

"We think it's a relatively straightforward activity," said Preston Burch, who manages the Hubble program at NASA's Goddard Space Flight Center. He added discussions are now underway as to whether or not the channel repair will bump other tasks from the Hubble repair mission. It's possible a camera repair planned for two spacewalks may be accomplished in one, which would free up that slot for the relay fix.

"This may be a doable thing, that we can have our cake and eat it too," Burch said.

It's possible that, on paper anyway, the on-orbit repair may be less complicated than the process NASA must undergo to activate the backup channel. Instructions on how to accomplish that are buried deep in the Hubble's owner's manual, so to speak... and the hardware used for the channel backup on Hubble has sat dormant for almost two decades.

FMI: www.nasa.gov/hubble