a satellite revolving in a circular orbit about the earth in the earth’s equatorial plane with an angular velocity equal to the angular velocity of the earth’s rotation on its axis. Stationary satellites permanently “hang” above the same point on the earth’s equator. This property of the satellites is used in constructing communications satellite systems (seeCOMMUNICATIONS SATELLITE). The altitude of stationary satellites above the surface of the earth is approximately 35,800 km.

The orbit of a stationary satellite is sometimes called a stationary orbit.