March 15, 2021 8:30 AM (EDT) Release ID: 2021-20

NASA Hubble Space Telescope's Wide Field Camera 3 restored

The Wide Field Camera 3 (WFC3) instrument of NASA’s Hubble Space Telescope was brought back online at approximately 7:00 p.m. EST Saturday, March 13. The instrument was shut down as part of the observatory’s normal safe mode operations that took place on Sunday, March 7, in response to a software error on the main flight computer. After the recovery began on Thursday, March 11, WFC3 halted the process due to a slightly below normal voltage reading for a power supply, triggering an internal instrument protection.

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The Wide Field Camera 3 (WFC3) instrument of NASA’s Hubble Space Telescope was brought back online at approximately 7:00 p.m. EST Saturday, March 13. The instrument was shut down as part of the observatory’s normal safe mode operations that took place on Sunday, March 7, in response to a software error on the main flight computer. After the recovery began on Thursday, March 11, WFC3 halted the process due to a slightly below normal voltage reading for a power supply, triggering an internal instrument protection.

Analysis showed that voltage levels in WFC3 power supplies have slowly decreased over time as their electronics age. The electronics will experience colder temperatures when the hardware is turned off in safe mode. This factor, coupled with the power that the instrument components decrease when turned back on, has contributed to the small voltage fluctuations that halt WFC3’s recovery operations. Further detailed analysis indicated that it would be safe to lower the low voltage limit slightly to avoid future interruption, and it would be safe to return the instrument to its scientific state.

The instrument has now been safely recovered. Standard instrument calibration and other pre-observation activities will be performed this week. WFC3 observations will then be incorporated into the scientific timeline so that the instrument can again collect data and continue to expand our understanding of the universe.