What is a geosynchronous orbit?

An orbit is the path an object takes as it travels around another object. Spacecraft in geosynchronous orbit at an altitude of 35,785 kilometers (22,236 miles), complete one orbit in exactly one day. Because the orbital velocity matches the spin rate of the Earth, a spacecraft in a circular equatorial geosynchronous orbit appears to hover motionless over a single location on the equator.

From this extremely high vantage point, a spacecraft can see effectively about one third of the Earth's surface. This broad view and the ability to hover over a single equatorial location makes geostationary orbits very popular for communications relay spacecraft and weather monitoring spacecraft. Syncom, was the first geosynchronous satellite launched.