Editing Hubble Space Telescope (section)

=== Orbital decay and controlled reentry ===
[[File:Soft Capture Mechanism installed on Hubble (illustration).jpg|thumb|Illustration of the Soft Capture Mechanism (SCM) installed on Hubble]]

Hubble orbits the Earth in the extremely tenuous upper [[Earth's atmosphere|atmosphere]], and over time its orbit [[orbital decay|decays]] due to [[drag (physics)|drag]]. If not [[reboost]]ed, it will re-enter the Earth's atmosphere within some decades, with the exact date depending on how active the Sun is and its impact on the upper atmosphere. If Hubble were to descend in a completely uncontrolled re-entry, parts of the main mirror and its support structure would probably survive, leaving the potential for damage or even human fatalities.<ref>{{cite news |url=http://news.bbc.co.uk/2/hi/science/nature/3406079.stm |title=Why Hubble is being dropped |work=BBC News |first=David |last=Whitehouse |date=January 17, 2004 |access-date=January 10, 2007 |archive-date=June 14, 2017 |archive-url=https://web.archive.org/web/20170614030822/http://news.bbc.co.uk/2/hi/science/nature/3406079.stm |url-status=live }}</ref> In 2013, deputy project manager James Jeletic projected that Hubble could survive into the 2020s.<ref name="cbsnews20130530">{{cite web |url=http://www.cbsnews.com/network/news/space/home/spacenews/files/1ae7cac0d167055e41e1f0da7b0ac6a3-588.html |title=Four years after final service call, Hubble Space Telescope going strong |work=CBS News |first=William |last=Harwood |date=May 30, 2013 |access-date=June 3, 2013 |archive-date=October 30, 2019 |archive-url=https://web.archive.org/web/20191030221153/http://www.cbsnews.com/network/news/space/home/spacenews/files/1ae7cac0d167055e41e1f0da7b0ac6a3-588.html |url-status=live }}</ref> Based on solar activity and atmospheric drag, or lack thereof, a natural atmospheric reentry for Hubble will occur between 2028 and 2040.<ref name="cbsnews20130530" /><ref>{{cite news |url=http://www.space.com/29206-how-will-hubble-space-telescope-die.html |title=How Will the Hubble Space Telescope Die? |work=Space.com |first=Mike |last=Wall |date=April 24, 2015 |access-date=May 16, 2017 |archive-date=May 5, 2017 |archive-url=https://web.archive.org/web/20170505052811/http://www.space.com/29206-how-will-hubble-space-telescope-die.html |url-status=live }}</ref> In June 2016, NASA extended the service contract for Hubble until June 2021.<ref>{{Cite press release |url=http://www.nasa.gov/press-release/nasa-extends-hubble-space-telescope-science-operations-contract |title=NASA Extends Hubble Space Telescope Science Operations Contract |publisher=NASA |last=Northon |first=Karen |date=June 23, 2016 |access-date=June 26, 2016 |archive-date=June 26, 2016 |archive-url=https://web.archive.org/web/20160626065803/http://www.nasa.gov/press-release/nasa-extends-hubble-space-telescope-science-operations-contract/ |url-status=live }}</ref> In November 2021, NASA extended the service contract for Hubble until June 2026.<ref>{{Cite press release |url=https://www.nasa.gov/feature/nasa-extends-hubble-operations-contract-provides-mission-update |title=NASA Extends Hubble Operations Contract, Provides Mission Update |publisher=NASA |last=Adkins |first=Jamie |date=November 16, 2021 |access-date=June 19, 2022 |archive-date=March 17, 2022 |archive-url=https://web.archive.org/web/20220317212639/https://www.nasa.gov/feature/nasa-extends-hubble-operations-contract-provides-mission-update/ |url-status=live }}</ref>

NASA's original plan for safely de-orbiting Hubble was to [[STS-144|retrieve it using a Space Shuttle]]. Hubble would then have most likely been displayed in the [[Smithsonian Institution]]. This is no longer possible since the [[Space Shuttle retirement|Space Shuttle fleet has been retired]], and would have been unlikely in any case due to the cost of the mission and risk to the crew. Instead, NASA considered adding an external propulsion module to allow controlled re-entry.<ref>{{cite news |url=http://www.spaceref.com/news/viewnews.html?id=1050 |first=Keith |last=Cowing |title=NASA Considering Deletion of Hubble Deorbit Module |date=July 22, 2005 |access-date=January 10, 2007 |publisher=SpaceRef |archive-date=May 30, 2012 |archive-url=https://archive.today/20120530063700/http://www.spaceref.com/news/viewnews.html?id=1050 |url-status=live }}</ref> Ultimately, in 2009, as part of Servicing Mission 4, the last servicing mission by the Space Shuttle, NASA installed the Soft Capture Mechanism (SCM), to enable deorbit by either a crewed or robotic mission. The SCM, together with the Relative Navigation System (RNS), mounted on the Shuttle to collect data to "enable NASA to pursue numerous options for the safe de-orbit of Hubble", constitute the Soft Capture and Rendezvous System (SCRS).<ref name="Soft Capture" /><ref>{{cite web |title=Servicing Missions |url=https://hubblesite.org/mission-and-telescope/servicing-missions |access-date=April 7, 2022 |website=HubbleSite.org |publisher=[[Space Telescope Science Institute]] |archive-date=April 9, 2022 |archive-url=https://web.archive.org/web/20220409085742/https://hubblesite.org/mission-and-telescope/servicing-missions |url-status=live }}</ref>