Editing Geosynchronous orbit (section)

== Retired satellites ==
[[File:Debris-GEO1280.jpg|thumb|alt=Earth from space, surrounded by small white dots|A computer-generated image of space debris. Two debris fields are shown: around geosynchronous space and low Earth orbit.]]
Geosynchronous satellites require some [[Orbital station-keeping|station-keeping]] in order to remain in position, and once they run out of thruster fuel and are no longer useful they are moved into a higher [[graveyard orbit]]. It is not feasible to deorbit geosynchronous satellites, for to do so would take far more fuel than would be used by slightly elevating the orbit; and atmospheric drag is negligible, giving GSOs lifetimes of thousands of years.<ref>{{cite web |url=https://www.nasa.gov/news/debris_faq.html |title=Frequently Asked Questions: Orbital Debris |publisher=NASA |date=September 2, 2011 |access-date=February 9, 2020 |archive-date=March 23, 2020 |archive-url=https://web.archive.org/web/20200323170238/https://www.nasa.gov/news/debris_faq.html |url-status=dead}}</ref>

The retirement process is becoming increasingly regulated and satellites must have a 90% chance of moving over 200&nbsp;km above the geostationary belt at end of life.<ref>{{cite web |url=https://phys.org/news/2017-04-satellites-die.html |title=Where old satellites go to die |website=phys.org |date=April 3, 2017 |author=EUMETSAT |author-link=EUMETSAT}}</ref>

=== Space debris ===
{{main|Space debris#Characterization}}
Space debris in geosynchronous orbits typically has a lower collision speed than at LEO since most GSO satellites orbit in the same plane, altitude and speed; however, the presence of satellites in [[eccentric orbit]]s allows for collisions at up to 4&nbsp;km/s. Although a collision is comparatively unlikely, GSO satellites have a limited ability to avoid any debris.<ref>{{cite web |url=https://physicsworld.com/a/space-debris-threat-to-geosynchronous-satellites-has-been-drastically-underestimated/ |title=Space debris threat to geosynchronous satellites has been drastically underestimated |date=December 12, 2017 |website=Physics World |first=Marric |last=Stephens}}</ref>

Debris less than 10&nbsp;cm in diameter cannot be seen from the Earth, making it difficult to assess their prevalence.<ref name="telk1">{{cite web |url=https://spacenews.com/exoanalytic-video-shows-telkom-1-satellite-erupting-debris/ |title=ExoAnalytic video shows Telkom-1 satellite erupting debris |date=August 30, 2017 |website=SpaceNews.com |first=Caleb |last=Henry}}</ref>

Despite efforts to reduce risk, spacecraft collisions have occurred. The [[European Space Agency]] telecom satellite [[Olympus-1]] was struck by a [[meteoroid]] on August 11, 1993, and eventually moved to a [[graveyard orbit]],<ref name="The Olympus failure">{{cite press release |title=N° 40–1993: OLYMPUS: End of mission |url=https://www.esa.int/Newsroom/Press_Releases/OLYMPUS_End_of_mission |publisher=[[ESA]] |access-date=23 May 2023 |archive-url=https://web.archive.org/web/20221031211545/https://www.esa.int/Newsroom/Press_Releases/OLYMPUS_End_of_mission |archive-date=31 October 2022 |date=26 August 1993 |url-status=live |id=40–1993}}</ref> and in 2006 the Russian [[Express (satellite)|Express-AM11]] communications satellite was struck by an unknown object and rendered inoperable,<ref name=srdc20060419>{{cite web |url=http://www.spaceref.com/news/viewsr.html?pid=20320 |archive-url=https://archive.today/20130104185122/http://www.spaceref.com/news/viewsr.html?pid=20320 |url-status=dead |archive-date=January 4, 2013 |title=Notification for Express-AM11 satellite users in connection with the spacecraft failure |publisher=Russian Satellite Communications Company |date=April 19, 2006 |via=Spaceref}}</ref> although its engineers had enough contact time with the satellite to send it into a graveyard orbit. In 2017 both [[AMC-9]] and [[Telkom-1]] broke apart from an unknown cause.<ref>{{cite web |url=https://spacenews.com/op-ed-do-we-care-about-orbital-debris-at-all/|title=Do we care about orbital debris at all? |first=James E. |last=Dunstan |date=January 30, 2018 |website=SpaceNews.com}}</ref><ref name="telk1"/><ref>{{cite web|url=http://spaceflight101.com/amc-9-satellite-anomaly-orbit-change/|title=AMC 9 Satellite Anomaly associated with Energetic Event & sudden Orbit Change – Spaceflight101|date=June 20, 2017|website=spaceflight101.com|access-date=January 27, 2020|archive-date=December 26, 2019|archive-url=https://web.archive.org/web/20191226011502/http://spaceflight101.com/amc-9-satellite-anomaly-orbit-change/|url-status=dead}}</ref>