In celestial mechanics, a stationary orbit is an orbit around a planet or moon where the orbiting satellite or spacecraft remains over the same spot on the surface. From the ground, the satellite would appear to be standing still, hovering above the surface in the same spot, day after day.[1]
In practice, this is accomplished by matching the rotation of the surface below, by reaching a particular altitude where the orbital speed almost matches the rotation below, in an equatorial orbit.[1] As the speed decreases slowly, then an additional boost would be needed to increase the speed back to a matching speed, or a retro-rocket could be fired to slow the speed when too fast.
The stationary-orbit region of space is known as the Clarke Belt, named after British science fiction writer Arthur C. Clarke, who published the idea in Wireless World magazine in 1945.[1] A stationary orbit is sometimes referred to as a "fixed orbit".