Discoverer 19

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 km, an apogee of 578 km, 83.4 degrees of inclination, and a period of 92.4 minutes. The satellite had a mass of 1060 kg, and was used to demonstrate technology for the Midas programme, including infrared sensors. Communication with the satellite was lost on Christmas Day 1960. It remained in orbit until 23 January 1961, when it decayed and reentered the atmosphere.