Orbital station-keeping

<p>In <a href="/facts/Astrodynamics/oB3tqNG9">astrodynamics</a>, orbital station-keeping is keeping a <a href="/facts/Spacecraft/YQqQaUw0">spacecraft</a> at a fixed distance from another spacecraft or celestial body. It requires a series of <a href="/facts/Orbital_maneuver/HAlEFRSJ">orbital maneuvers</a> made with <a href="/facts/Spacecraft_propulsion/KmpMGU9u">thruster burns</a> to keep the active craft in the same orbit as its target. For many <a href="/facts/Low_Earth_orbit/rq1TwayJ">low Earth orbit</a> satellites, the effects of <a href="/facts/Orbital_perturbation_analysis_(spacecraft)/og5hPpjQ">non-Keplerian</a> forces, i.e. the deviations of the gravitational force of the Earth from that of a <a href="/facts/Shell_theorem/jVN9eNT0">homogeneous sphere</a>, gravitational forces from Sun/Moon, <a href="/facts/Solar_radiation_pressure/xA6japY0">solar radiation pressure</a> and air <a href="/facts/Drag_(physics)/vdl4jF7I">drag</a>, must be counteracted.
For spacecraft in a <a href="/facts/Halo_orbit/NnTW9mnT">halo orbit</a> around a <a href="/facts/Lagrange_point/XCAN4o3P">Lagrange point</a>, station-keeping is even more fundamental, as such an orbit is unstable; without an active control with thruster burns, the smallest deviation in position or velocity would result in the spacecraft leaving orbit completely.
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Orbital station-keeping open-in-new

Orbital station-keeping