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 Launch Complex 75-3-5 at the Vandenberg Air Force Base. Upon successfully reaching orbit, it was assigned the Harvard designation 1960 Tau 1.
Discoverer 19 was operated in a low Earth orbit, with a perigee of 206 kilometres (Template:Convert/round mi), an apogee of 578 kilometres (Template:Convert/round mi), 83.4 degrees of inclination, and a period of 92.4 minutes. The satellite had a mass of 1,060 kilograms (Template:Convert/round lb), and was used to demonstrate technology for the Midas programme, including infrared sensors. It remained in orbit until 23 January 1961, when it decayed and reentered the atmosphere.