Editing Orbit (section)

==Astrodynamics==
{{Main|Orbital mechanics}}
Orbital mechanics or astrodynamics is the application of [[ballistics]] and [[celestial mechanics]] to the practical problems concerning the motion of [[rocket]]s and other [[spacecraft]]. The motion of these objects is usually calculated from [[Newton's laws of motion]] and [[Newton's law of universal gravitation]]. It is a core discipline within space mission design and control. Celestial mechanics treats more broadly the orbital dynamics of systems under the influence of [[gravity]], including spacecraft and natural astronomical bodies such as star systems, [[planet]]s, [[Natural satellite|moon]]s, and [[comet]]s. Orbital mechanics focuses on spacecraft [[trajectory|trajectories]], including [[orbital maneuver]]s, orbit plane changes, and interplanetary transfers, and is used by mission planners to predict the results of [[Spacecraft propulsion|propulsive maneuvers]]. [[General relativity]] is a more exact theory than Newton's laws for calculating orbits, and is sometimes necessary for greater accuracy or in high-gravity situations (such as orbits close to the Sun).