Hubble reconfigured to one gyroscope at 35

NASA said on June 4, 2024 that it was reconfiguring the Hubble Space Telescope to operate with a single gyroscope after repeated faulty readings from one of the observatory’s three remaining gyros forced it into safe mode on May 24. The agency said the shift would allow Hubble to continue science operations “through this decade and into the next,” with most observations unaffected. Hubble returned to daily science operations on June 14 in the new mode, according to NASA. The move came 35 years after the telescope’s April 1990 launch. ### Why did NASA stop using Hubble’s normal setup? NASA said on May 31, 2024 that Hubble had entered safe mode a week earlier because one gyro was sending faulty telemetry. The telescope’s instruments remained stable and the spacecraft stayed in good health while engineers worked through options, the agency said. (science.nasa.gov) The June 4 decision followed months of recurring trouble with the same gyro. NASA said that over the previous six months the unit had increasingly produced bad readings, triggering multiple safe-mode events and interrupting observations. ### What does one gyroscope actually change? (science.nasa.gov) Hubble’s gyroscopes measure turn rates and help the telescope point and hold steady on targets. NASA said the observatory was designed with a one-gyro operating mode as a fallback if four or five of its original six gyros failed, allowing science to continue with some limitations. (science.nasa.gov) In the one-gyro configuration, NASA said another working gyro can be held in reserve rather than used continuously. The agency said that approach should support more consistent science operations and preserve hardware for later use. ### Which observations are affected, and which are not? (science.nasa.gov) NASA said on June 4 that the “majority” of Hubble observations would be unaffected in one-gyro mode. The agency said some observations would take longer, especially those requiring very precise pointing, and that Hubble would be less efficient when moving between targets. (hubblesite.org) The operating change does not alter Hubble’s instruments themselves. NASA said the telescope and its instruments were stable and functioning normally when science operations resumed. ### When did Hubble get back to work? NASA said Hubble returned to science operations on June 14, 2024 after several weeks offline. (science.nasa.gov) The agency later released an image of galaxy NGC 1546, in the constellation Dorado, as one of the first results from the new pointing mode. (spacecoastdaily.com) The June 14 restart confirmed that engineers had completed the transition announced during a June 4 media teleconference. The Space Telescope Science Institute also described the change as a move from three-gyro operations to observing with one gyro while keeping another operational unit available for future use. (science.nasa.gov) ### How long has NASA planned for this possibility? The 2009 shuttle servicing mission installed six new gyros on Hubble, and NASA said three of those remained operational before the latest problem. The agency had already built one-gyro procedures into Hubble’s pointing control system years earlier as a contingency for aging hardware. (hubblesite.org) NASA’s own Hubble history page says one-gyro mode began being used in June 2024 to extend the observatory’s life after more than three decades in orbit. That record places the latest reconfiguration in the same line of life-extension measures that have kept Hubble operating long past its original design life. (science.nasa.gov) ### What comes next for the telescope? NASA’s next public markers after the June 2024 switchover were new science releases from the one-gyro configuration, beginning with NGC 1546. The agency’s Hubble mission pages continue to document the observatory’s operating status, instrument output and any future updates on gyro performance. (science.nasa.gov 1) (science.nasa.gov 2)