Posted 12 March; updated 15 March with recovery of Wide Field Camera 3
The Hubble Space Telescope, nearing its 31st year in orbit, is showing its age.
Engineers are troubleshooting problems with the motorised system used to open and close the telescope’s aperture door amid recovery from a software glitch that briefly shut down operations.
The famed observatory’s central computer put the telescope into “safe mode,” a sort of electronic hibernation, on 7 March after detecting an error in a software update need to compensate for fluctuations in one of the gyroscopes used to move to and lock onto targets.
After analysing the issue, engineers instructed the computer to ignore the offending code while a patch is prepared and the telescope was moved out of safe mode in preparation for resumption of science operations on 11 March.
In the process of troubleshooting, engineers noticed the telescope’s protective aperture door failed to close on computer command. Closing the door is a protective measure when entering safe mode to prevent any chance of damaging heat and sunlight from entering the telescope’s tube.
Additional attempts to close the door with commands sent directly to the primary motor also failed, but the same instructions appeared to work when directed to a backup motor. Hubble’s computer software has been updated to make that motor primary while engineers continue troubleshooting.
As if all that wasn’t enough, when moving the spacecraft out of safe mode, the Wide Field Camera 3 ran into an error that prevented it from returning to operation. After a detailed analysis, engineers determined the glitch was caused by an aging power supply and low temperatures resulting from safe mode operations. The camera was successfully returned to service on 13 March.