All’s Not Well With Hubble, Yet
Plan B From Outer Space
Side A of the Hubble Space Telescope’s Science Data Formatter (the SDF) failed last month. Teams at GSFC and STSCi attempted late last week to bring up SDF Side B, the back-up channel which has not seen operation since Hubble was launched in 1990. You just knew that this wasn’t going to go without a hitch, didn’t you?
Engineers at NASA’s Hubble operations center at Goddard worked around the clock to make the transition, which included uploading hundreds of computer commands to reroute systems.
But during calibration checks on Thursday, a component of Hubble’s main camera returned a lower than normal voltage. The second glitch revolved around a communications drop out between Hubble’s main computer and one that governs its science instruments, which sent the telescope back into a protective “safe mode.”
You may remember that one of the original problems with HST was that it put itself into “safe mode”, a sort of unproductive, self-protective crouch, very readily when it was launched. Too readily. It safed itself four times at the beginning of the mission, at least until engineers “opened up” some of the instrument’s critical parameters.
“We remain optimistic at this time for recovering full science operations,” said Jon Morse, director of astrophysics with NASA’s Science Directorate. “But even the best laid plans can encounter some unanticipated difficulties.”
They’re not giving up on recovery, yet, and in fact, it would have been surprising if something of this sort hadn’t happened.
Whipple stressed that Hubble engineers were not unprepared for Thursday’s glitches, and have several options to work through or around the malfunctions. They could even reactivate Hubble using a hybrid approach that patches the telescope’s main science instruments through parts of both the Side A and Side B channels, he added.
“It was not unexpected that there might be issues,” Whipple said, adding that Hubble engineers are fully confident they can revive the telescope before next year’s planned shuttle mission to overhaul the observatory. “We expect that we will work through it and we will be back up and doing science before the servicing mission.”
No schedule for bringing HST out of safe mode has been announced, yet.