| Kosmos 31 | |
| Mission Type: | Technology Cosmic ray |
| Operator: | VNIIEM |
| Cospar Id: | 1964-028A |
| Satcat: | 00803 |
| Mission Duration: | 136 days |
| Spacecraft Type: | DS-MT |
| Manufacturer: | Yuzhnoye |
| Launch Mass: | 325 kg[1] |
| Launch Date: | 6 June 1964, 06:00:00 GMT |
| Launch Rocket: | Kosmos-2I 63S1 |
| Launch Site: | Kapustin Yar, Mayak-2 |
| Decay Date: | 20 October 1964 |
| Orbit Epoch: | 6 juin 1964 |
| Orbit Reference: | Geocentric[2] |
| Orbit Regime: | Low Earth |
| Orbit Periapsis: | 222 km |
| Orbit Apoapsis: | 492 km |
| Orbit Inclination: | 49.0° |
| Orbit Period: | 91.6 minutes |
| Apsis: | gee |
Kosmos 31 (ru|Космос 31 meaning Cosmos 31), also known as DS-MT No.2 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.[3]
It was launched aboard a Kosmos-2I 63S1 rocket[4] from Mayak-2 at Kapustin Yar. The launch occurred at 06:00 GMT on 6 June 1964.[5]
Kosmos 31 was placed into a low Earth orbit with a perigee of, an apogee of, 49.0° of inclination, and an orbital period of 91.6 minutes. It decayed from orbit on 20 October 1964.[6] Kosmos 31 was the second of three DS-MT satellites to be launched. The first, DS-MT No.1, was lost in a launch failure on 1 June 1963, and the third will be Kosmos 51, which will be launched on 9 December 1964.[7]