Discoverer 19, also known as RM-1, was an American satellite which was launched in 1960. It was a technology demonstration spacecraft, based on an Agena-B. The launch of Discoverer 19 occurred at 20:32 UTC on 20 December 1960. A Thor DM-21 Agena-B rocket was used, flying from at the Vandenberg Air Force Base. Upon successfully reaching orbit, it was assigned the 1960 Tau 1.