On November 29, 2023, NASA’s Hubble Space Telescope paused science operations due to a gyroscope (gyro) issue. The telescope switched to safe mode automatically after one of its three gyroscopes provided inaccurate readings.
Gyroscopes help measure the telescope’s turn rates and play a role in determining its pointing direction. When in safe mode, scientific operations are halted, and the telescope awaits new instructions from the ground.
Hubble initially entered safe mode on November 19. Although the operations team recovered the spacecraft, allowing it to resume observations the next day, the gyro instability led to another suspension of science operations on November 21. Following a successful recovery, Hubble entered safe mode again on November 23.
Since then, the team has been running tests to characterize the issue and develop solutions. Following data analysis, the team has concluded that science operations can resume using three-gyro control. Observing the gyros’ performance during tests, the team has chosen to operate them in a higher-precision mode during scientific observations.
NASA restored the agency’s Hubble Space Telescope to science operations on Friday, December 8. The spacecraft is in good health and again operates using all three gyros.
Hubble’s primary cameras, the Wide Field Camera 3 and Advanced Camera for Surveys, have recommenced scientific observations as of Friday. The team intends to reinstate operations for the Cosmic Origins Spectrograph and Space Telescope Imaging Spectrograph later this month.