NASA readies commands to switch on Hubble's back-up hardware

Observatory might be able to spot distant stars, but it can't hear a bunch of engineers holding their breath

NASA is preparing to have another crack at restoring the veteran Hubble telescope to service with a multi-day test of procedures to fire up back-up hardware aboard the spacecraft.

After US Independence Day celebrations drew to a close, engineers kicked off procedures to switch more of the Hubble's internals to back-up units, in the hope of dealing with whatever upset the payload computer and sent the telescope into safe mode nearly a month ago.

A multi-day test of procedures that would be used to turn on backup hardware on the Hubble Space Telescope began today.

Meanwhile, NASA continues to investigate the cause of the payload computer issue that began on June 13.

For previous updates: https://t.co/rQ8PGjBhm0

— Hubble (@NASAHubble) July 6, 2021

The problem has proven to be a tricky one for engineers to fix and, since there is no chance of a servicing mission (thanks to the retirement of the Space Shuttles), any resolution must be accomplished from the ground.

Former astronauts and managers alike have weighed in on the fate of the telescope, with some fearing the writing might be on the wall for the over-three-decades-old observatory.

The issue, which has resulted in the failure to read and write from memory modules by both the primary and backup payload computers, sounds like a low-level one to us.

An engineer with experience in managing spacecraft told The Reg that an inability to reliably load and execute programs on the Hubble's systems due to the failures would likely dash any hopes that the payload could perhaps be run directly from the ground, bypassing the onboard borkage.

The Hubble (up until the current issue, that is) makes use of the geosynchronous Tracking and Data Relay Satellite System (TDRSS) to downlink science data stored in its solid state memory modules to Earth. One option could be to route that data directly to the ground, although we imagine there are substantial barriers to doing so from both a software and operational standpoint.

A glance at our Space Extenders series shows how creative engineers can keep spacecraft going, even when all is thought lost.

However, with budgets strained, some within NASA may wish to cut their losses and focus on the impending launch of the James Webb Space Telescope, currently set for later this year.

Ultimately, our source told us, the best bet for Hubble would be to identify the failed bit of hardware and find a configuration that bypasses the faulty component. Doing so, however, will require a complicated sequence of commands. A borked step could easily make the current safe mode state more permanent than scientists would prefer.

NASA reckons it has worked out the procedures to turn on the back-up hardware and has kicked off a test before uploading the commands to the stricken 'scope.

Should the test go well, then the sequence can be sent to Hubble and its long hiatus from observations might at last be brought to an end. ®