| Mission type | Deep space and return to Earth (test for Venus impact)[1] |
|---|---|
| Operator | OKB-1 |
| COSPAR ID | 1963-044A |
| SATCAT no. | 00687 |
| Mission duration | 3 days |
| Spacecraft properties | |
| Spacecraft type | 3MV-1A |
| Manufacturer | OKB-1 |
| Launch mass | 890 kg[2] |
| Start of mission | |
| Launch date | 11 November 1963 06:23:34 GMT |
| Rocket | Molniya 8K78M s/n G103-18[1] |
| Launch site | Baikonur, Site 1/5 |
| Contractor | OKB-1 |
| End of mission | |
| Disposal | Upper stage failure |
| Decay date | 14 November 1963 |
| Orbital parameters | |
| Reference system | Geocentric[3] |
| Regime | Low Earth |
| Perigee altitude | 182 km |
| Apogee altitude | 216 km |
| Inclination | 64.8° |
| Period | 88.5 minutes |
| Epoch | 11 November 1963 |
Kosmos 21 (Russian: Космос 21 meaning Cosmos 21) was a Soviet spacecraft. This mission has been tentatively identified by NASA as a technology test of the Venera series space probes. It may have been an attempted Venus impact, presumably similar to the later Kosmos 27 mission, or it may have been intended from the beginning to remain in geocentric orbit. In any case, the spacecraft never left Earth orbit after insertion by the Molniya launcher. The orbit decayed on 14 November 1963, three days after launch.
- ^ a b Siddiqi, Asif A. (2018). Beyond Earth: A Chronicle of Deep Space Exploration, 1958–2016 (PDF). The NASA history series (second ed.). Washington, D.C.: NASA History Program Office. pp. 54–55. ISBN 9781626830424. LCCN 2017059404. SP2018-4041.
- ^ https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1963-044A - 27 February 2020
- ^ https://nssdc.gsfc.nasa.gov/nmc/spacecraft/displayTrajectory.action?id=1963-044A - 27 February 2020