Communications satellite. Computer illustration of a communications satellite in space orbiting the Earth. Clouds are seen blanketing much of the Earth. The satellite has two solar cell arrays (blue) to produce power, and a rounded dish antenna to receive and transmit communication signals. These satellites act as relay vehicles for radio signals. Communication satellites usually have a high geostationary orbit and hover at the same point above the Earth. These satellites may be used to relay telephone and fax messages, computer data, and to broadcast television signals.