Editing Hubble Space Telescope (section)

==== 2021 power control issue ====
On June 13, 2021, Hubble's payload computer halted due to a suspected issue with a memory module. An attempt to restart the computer on June 14 failed. Further attempts to switch to one of three other backup memory modules on board the spacecraft failed on June 18. On June 23 and 24, NASA engineers switched Hubble to a backup payload computer, but these operations have failed as well with the same error. On June 28, 2021, NASA announced that it was extending the investigation to other components.<ref>{{Cite web|date=June 26, 2021|title=NASA Continues Work on Hubble Space Telescope – Backup Computer Turned On, but It Fails With the Same Error|url=https://scitechdaily.com/nasa-continues-work-on-hubble-space-telescope-backup-computer-turned-on-but-it-fails-with-the-same-error/|access-date=June 26, 2021|website=SciTechDaily|archive-date=June 26, 2021|archive-url=https://web.archive.org/web/20210626142712/https://scitechdaily.com/nasa-continues-work-on-hubble-space-telescope-backup-computer-turned-on-but-it-fails-with-the-same-error/|url-status=live}}</ref><ref>{{Cite web |last=Mathewson |first=Samantha |date=2021-06-28 |title=No quick fix for Hubble Space Telescope's computer glitch, NASA says |url=https://www.space.com/nasa-investigates-hubble-space-telescope-computer-glitch |access-date=2023-10-15 |website=Space.com |language=en-us |archive-date=July 15, 2022 |archive-url=https://web.archive.org/web/20220715150344/https://www.space.com/nasa-investigates-hubble-space-telescope-computer-glitch |url-status=live }}</ref> Scientific operations were suspended while NASA worked to diagnose and resolve the issue.<ref name="AP: Computer trouble, science halted">{{Cite web |last=Dunn |first=Marcia |date=June 16, 2021 |title=Computer trouble hits Hubble Space Telescope, science halted |url=https://apnews.com/article/business-science-d0042c12554759cf2d00668d5dcd031b |access-date=June 20, 2021 |website=[[Associated Press|AP NEWS]] |archive-date=June 16, 2021 |archive-url=https://web.archive.org/web/20210616205037/https://apnews.com/article/business-science-d0042c12554759cf2d00668d5dcd031b |url-status=live }}</ref><ref>{{Cite web |last=Jenner |first=Lynn |date=June 16, 2021 |title=Operations Underway to Restore Payload Computer on NASA's Hubble |url=http://www.nasa.gov/feature/goddard/2021/operations-underway-to-restore-payload-computer-on-nasas-hubble-space-telescope |access-date=June 20, 2021 |website=NASA |archive-date=June 20, 2021 |archive-url=https://web.archive.org/web/20210620010610/http://www.nasa.gov/feature/goddard/2021/operations-underway-to-restore-payload-computer-on-nasas-hubble-space-telescope/ |url-status=live }}</ref> After identifying a malfunctioning power control unit (PCU) supplying power to one of Hubble's computers, NASA was able to switch to a backup PCU and bring Hubble back to operational mode on July 16.<ref>{{Cite web |date=2021-07-19 |title=NASA Returns Hubble Space Telescope to Science Operations – NASA |url=https://www.nasa.gov/solar-system/nasa-returns-hubble-space-telescope-to-science-operations/ |access-date=2023-10-15 |language=en-US |archive-date=October 23, 2023 |archive-url=https://web.archive.org/web/20231023194702/https://www.nasa.gov/solar-system/nasa-returns-hubble-space-telescope-to-science-operations/ |url-status=live }}</ref><ref>{{Cite web|title=Hobbled Hubble Telescope Springs Back To Life On Its Backup System|url=https://www.npr.org/2021/07/16/1016953132/hobbled-hubble-telescope-springs-back-to-life-on-its-backup-system|access-date=July 16, 2021|website=NPR|date=July 16, 2021 |archive-date=July 16, 2021|archive-url=https://web.archive.org/web/20210716201637/https://www.npr.org/2021/07/16/1016953132/hobbled-hubble-telescope-springs-back-to-life-on-its-backup-system|url-status=live|last1=Chappell |first1=Bill }}</ref><ref>{{cite news|last=Clery|first=Daniel|date=July 16, 2021|title='Hubble is back!' Famed space telescope has new lease on life after computer swap appears to fix glitch|url=https://www.science.org/content/article/hubble-back-famed-space-telescope-has-new-lease-life-after-computer-swap-appears-fix|work=[[Science (magazine)|Science]]|location=|access-date=July 16, 2021|archive-date=October 21, 2021|archive-url=https://web.archive.org/web/20211021183821/https://www.science.org/content/article/hubble-back-famed-space-telescope-has-new-lease-life-after-computer-swap-appears-fix|url-status=live}}</ref><ref>{{cite news|last=Hunt|first=Katie|date=July 19, 2021|title=The Hubble Space Telescope is functioning again after more than month offline|url=https://www.cnn.com/2021/07/19/world/hubble-telescope-nasa-scn/index.html|work=[[CNN]]|location=|access-date=July 19, 2021|archive-date=July 19, 2021|archive-url=https://web.archive.org/web/20210719131659/https://www.cnn.com/2021/07/19/world/hubble-telescope-nasa-scn/index.html|url-status=live}}</ref> On October 23, 2021, HST instruments reported missing synchronization messages<ref>{{cite web |url=https://hubblesite.org/contents/news-releases/2021/news-2021-064 |title=Hubble Instruments Remain in Safe Mode, NASA Team Investigating |website=HubbleSite.org |publisher=[[Space Telescope Science Institute]] |date=November 4, 2021 |access-date=November 24, 2021 |archive-date=November 24, 2021 |archive-url=https://web.archive.org/web/20211124151859/https://hubblesite.org/contents/news-releases/2021/news-2021-064 |url-status=live }}</ref> and went into safe mode.<ref>{{cite web|url=https://www.space.com/hubble-space-telescope-wide-field-camera-3-recovered|title=Hubble Space Telescope team revives powerful camera instrument after glitch|website=[[Space.com]]|date=November 22, 2021|access-date=November 24, 2021|archive-date=November 23, 2021|archive-url=https://web.archive.org/web/20211123205854/https://www.space.com/hubble-space-telescope-wide-field-camera-3-recovered|url-status=live}}</ref> By December 8, 2021, NASA had restored full science operations and was developing updates to make instruments more resilient to missing synchronization messages.<ref>{{Cite web |last=Adkins |first=Jamie |date=December 8, 2021 |title=NASA Returns Hubble to Full Science Operations |url=https://www.nasa.gov/feature/goddard/2021/nasa-returns-hubble-to-full-science-operations |access-date=December 8, 2021 |website=NASA |archive-date=December 7, 2021 |archive-url=https://web.archive.org/web/20211207235922/http://www.nasa.gov/feature/goddard/2021/nasa-returns-hubble-to-full-science-operations/ |url-status=live }}</ref>