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geosynchronous orbit

A geosynchronous orbit is a direct, circular, low-inclination orbit around Earth having a period of 23 hours 56 minutes 4 seconds and a corresponding altitude of 35,784 km (22,240 miles, or 6.6 Earth radii). In such an orbit, a satellite maintains a position above Earth that has the same longitude. However, if the orbit's inclination is not exactly zero, the satellite's ground-track describes a figure eight. In most cases, the orbit is chosen to have a zero inclination, and station-keeping procedures are carried out so that the spacecraft hangs motionless with respect to a point on the planet below. In this case, the orbit is said to be a geostationary orbit.

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