A computer key to the operation of NASA’s Hubble Space Telescope has stopped working and a number of attempts to restart it have so far failed.
As NASA explains, the payload computer on the telescope “halted” shortly after 4pm ET on June 13. This machine is a NASA Standard Spacecraft Computer-1 (NSSC-1) developed in the 1980s and used as part of the Science Instrument Command and Data Handling module in order to “control and coordinate the science instruments onboard the spacecraft.”
The payload computer is meant to send a “keep-alive” signal to the main spacecraft computer, but that’s not happening since the failure so the main computer triggered the automatic safety measure of placing all science instruments into a safe mode configuration. They will remain in that mode until NASA figures out a way to fix the payload computer.
An investigation suggested the computer ceased to function due to a degrading memory module. As you’d expect, NASA has three backup memory modules it can switch between if necessary, but the command to initiate a backup module also failed. A further attempt on both the original and backup module failed again on Thursday evening, suggesting there’s another fault yet to be discovered. On Friday, NASA’s operations team started running more tests to collect more detailed information to help pinpoint the cause of the failure. That testing is ongoing with no further updates issued since then.
There is a second computer which can be switched over to, but it depends on the same four independent memory modules. NASA says the 31-year-old telescope and all the science instruments remain in good health, but unless the payload computer can be brought back into operation they won’t be able to collect and send back anymore valuable data.
