An amateur radio satellite is an artificial satellite built and used by amateur radio operators for use in the amateur radio satellite service. The first amateur radio satellite was OSCAR-1, launched on December 12, 1961, in the United States.
The first amateur satellites contained telemetry beacons. Since 1965, most satellites carry a linear transponder for two-way communications in real time. Some satellites have a bulletin board for store-and-forward digital communications, or a digipeater for direct packet radio connections.
Amateur satellites have been launced into low Earth orbits and into highly elliptical orbits.