Hubble is finally fixed after several weeks of shutdown

After more than a month in Safe Mode, the Hubble Space Telescope is finally on the mend. The observatory shut down on June 13 due to a problem with its payload computer.

Hubble is getting old!
Hubble had halted operations on Sunday, June 13, 2021 due to an issue with its payload computer, which resides in the Science Instrument Command and Data Handling (SI C&DH) unit. However, it is he who controls the scientific instruments of Hubble. When this computer shut down, the instruments were automatically placed in safe mode.

Unfortunately, subsequent attempts to restart and reconfigure the computer and its backup computer were unsuccessful. However, the information gathered from these maintenance activities enabled engineers to determine that the possible cause of the problem lies in the Power Control Unit (PCU) which supplies power to the computer hardware.

Concretely, the PCU offers a power regulator that supplies constant electricity of five volts to the payload computer and its memory. A secondary protection circuit is then responsible for detecting abnormal voltage levels. If the voltage drops below or exceeds allowable levels, this secondary circuit signals the payload computer to shut down.

According to the analysis of the Hubble team, either the voltage level of the regulator was here outside the acceptable levels (thus triggering the secondary protection circuit), or the secondary protection circuit had degraded over time. to finally get stuck in this configuration.

Extensions until 2030?
Since the PCU reset could not be done from the ground, the team had to switch to the backup PCU. These operations began on July 15. The next day, NASA had successfully activated the backup computer system. All the telescope’s scientific instruments were finally reactivated on July 17th. The latter will resume scientific observations after completing the calibrations.

“I am proud of the Hubble team. Current and former members of this team have stepped in to provide support and expertise, ”said NASA Administrator Bill Nelson, the new NASA Administrator. “Through their dedication and thoughtful work, Hubble will continue to build on its 31-year heritage, expanding our horizons with its view of the universe.”

Astronomers remain optimistic that Hubble, which contributed to some of the most important discoveries in our cosmos, including the accelerating expansion of the universe, can continue to operate until 2030.