Editing Geosynchronous orbit (section)

==Launch==
{{see also|Geostationary transfer orbit}}
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| footer            = An example of a transition from Geostationary Transfer Orbit (GTO) to Geosynchronous Orbit (GSO):<br />{{legend2|magenta|[[EchoStar XVII]]}}{{·}}{{legend2|RoyalBlue|[[Earth]]}}.
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Geosynchronous satellites are launched to the east into a prograde orbit that matches the rotation rate of the equator. The smallest inclination that a satellite can be launched into is that of the launch site's latitude, so launching the satellite from close to the equator limits the amount of [[Orbital inclination change|inclination change]] needed later.<ref name="conf"/> Additionally, launching from close to the equator allows the speed of the Earth's rotation to give the satellite a boost. A launch site should have water or deserts to the east, so any failed rockets do not fall on a populated area.<ref>{{cite web|url=https://www.eumetsat.int/website/home/Satellites/LaunchesandOrbits/LaunchingSatellites/index.html|title=Launching Satellites|website=[[EUMETSAT]]|access-date=January 26, 2020|archive-date=December 21, 2019|archive-url=https://web.archive.org/web/20191221164243/https://www.eumetsat.int/website/home/Satellites/LaunchesandOrbits/LaunchingSatellites/index.html|url-status=dead}}</ref>

Most [[launch vehicle]]s place geosynchronous satellites directly into a [[geosynchronous transfer orbit]] (GTO), an elliptical orbit with an [[apsis|apogee]] at GSO height and a low [[apsis|perigee]]. On-board satellite propulsion is then used to raise the perigee, circularise and reach GSO.<ref name="conf">{{cite conference|url=https://www.researchgate.net/publication/282014319 |conference=20th International Symposium on Space Flight Dynamics|first1=Nicholas |last1=Farber |first2=Andrea |last2=Aresini |first3=Pascal |last3=Wauthier |first4=Philippe |last4=Francken|date=September 2007 |title=A general approach to the geostationary transfer orbit mission recovery |page=2}}</ref><ref>{{cite web|url=http://www.planetary.org/blogs/jason-davis/20140116-how-to-get-a-satellite-to-gto.html |title=How to get a satellite to geostationary orbit |first=Jason |last=Davis|date=January 17, 2014|access-date=October 2, 2019 |publisher=The Planetary Society}}</ref>

Once in a viable geostationary orbit, spacecraft can change their longitudinal position by adjusting their semi-major axis such that the new period is shorter or longer than a sidereal day, in order to effect an apparent "drift" Eastward or Westward, respectively.  Once at the desired longitude, the spacecraft's period is restored to geosynchronous.<ref name="satsig-repo-gso">{{cite web |title=Repositioning geostationary satellites |url=https://www.satsig.net/orbit-research/geo-orbit-repositioning.htm |website=Satellite Signals |access-date=23 May 2023 |archive-url=https://web.archive.org/web/20221127202135/https://www.satsig.net/orbit-research/geo-orbit-repositioning.htm |archive-date=27 November 2022 |date=22 February 2022 |url-status=live}}</ref>