Kosmos 51 (Russian: Космос 51 meaning Cosmos 51), also known as DS-MT No.3 was a technology demonstration satellite which was launched by the Soviet Union in 1964 as part of the Dnepropetrovsk Sputnik programme. Its primary mission was to demonstrate an electric gyrodyne orientation system.[3] It also carried a scientific research package as a secondary payload, which was used to study cosmic rays and the luminosity of the stellar background.
Kosmos 51 was placed into a low Earth orbit with a perigee of 262 kilometres (163 mi), an apogee of 533 kilometres (331 mi), 48.8° of inclination, and an orbital period of 92.5 minutes. It decayed from orbit on 14 November 1965.[6] Kosmos 51 was the last of three DS-MT satellites to be launched. The first was lost in a launch failure on 1 June 1963, and the second was launched as Kosmos 31 on 6 June 1964.[7]
