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

The Wide Field Camera 3 (WFC3) instrument on NASA’s Hubble Space Telescope was returned to the network on Saturday, March 13, at approximately 7:00 p.m. EST. The instrument was shut down as part of the Safe Observatory’s usual activities that occurred on Sunday, March 7, in response to a software error on the main flight computer. Following the launch of the recovery on Thursday, March 11, WFC3 suspended the proceedings due to a voltage reading slightly lower than normal, which triggered the instrument’s internal protection.

Title of the research framework

The Wide Field Camera 3 (WFC3) instrument on NASA’s Hubble Space Telescope was returned to the network on Saturday, March 13, at approximately 7:00 p.m. EST. The instrument was shut down as part of the Safe Observatory’s usual activities that occurred on Sunday, March 7, in response to a software error on the main flight computer. Following the launch of the recovery on Thursday, March 11, WFC3 suspended the proceedings due to a voltage reading slightly lower than normal, which triggered the instrument’s internal protection.

The analysis showed that the voltage levels in WFC3 power supplies slowly decrease over time as their electronics age. Electronics experience cooler temperatures when the hardware is turned off in safe mode. This factor, together with the power drawn by the instrument components when restarted, contributed to small voltage fluctuations that stopped WFC3 recovery operations. Further detailed analysis showed that it would be safe to slightly reduce the low voltage limit to avoid future suspension, and it would be safe to return the instrument to its scientific state.

The instrument is now safely returned. Standard instrument calibration and other observation activities will be conducted this week. WFC3 observations will then be included in the timeline of science so that the instrument can reassemble the data and continue to expand our understanding of the universe.