Hubble Space Telescope sails serenely on in safe mode after efforts to switch to backup memory modules fail
Updated The Hubble Space Telescope has continued to resist efforts by NASA last week to bring its payload computer back online.
It has now been more than a week since the computer halted on Sunday 13 June. An attempt to restart it the following Monday failed with initial indications pointing to a failing memory module.
At the time, a NASA spokesperson told The Register that the veteran telescope only required one of its four memory modules and so planned to swap to a backup module in order to resume operations.
According to NASA, "the command to initiate the backup module failed to complete." The team had another crack at bringing up both modules on Thursday 17 June but again failed.
While Hubble was designed to be serviceable by astronauts, its hardware is also highly redundant. As well as the four memory modules, there are two onboard computers. Only one is required for normal operations and the telescope can switch over to the other in the event of a problem. Both can access and use any one of those four independent memory modules, each of which contains 64K of CMOS memory.
The payload computer itself is a NASA Standard Spacecraft Computer-1 (NSSC-1) system built in the 1980s. Although the telescope and its science instruments remain in good health, the computer is required to coordinate and monitor the payload.
