NASA is preparing to switch key systems aboard the Hubble Space Telescope to backup hardware to bypass a fault that crippled it.
On June 13, Hubble’s payload computer unexpectedly failed, forcing the telescope’s science hardware into a safe mode configuration. An initial investigation identified one of four independent memory modules as the cause. However, when operations to bypass the module failed to rectify the problem, NASA engineers were forced to look elsewhere.
After a several-week-long investigation, a NASA update on June 30 identified the Science Instrument Command and Data Handling unit as the most likely culprit of the failure. Despite having a rough idea of where to look, the update admitted that the issue could have stemmed from a “few hardware pieces.”
The two most likely culprits are the Command Unit/Science Data Formatter (CU/SDF), which sends and formats commands and data, and the Power Control Unit, which is designed to ensure a steady voltage supply to the payload computer’s hardware.
Teams spent early July designing and testing operations procedures, commands, and other related items necessary to perform the switch to bypass the affected hardware.
In a July 12 update, NASA announced that it had completed testing on a high-fidelity simulator and was ready to proceed with the operation to make the switch later this week.
While NASA prepares to switch to backup hardware to bypass the issue, the investigation into the cause of the payload computer failure is ongoing.