Mars 4
| Mission type | Mars orbiter |
|---|---|
| Operator | Soviet space program |
| COSPAR ID | 1973-047A |
| SATCAT no. | 6742 |
| Mission duration | 203 days, 20 hours and 7 minutes |
| Spacecraft properties | |
| Spacecraft | 3MS No.52S |
| Manufacturer | NPO Lavochkin |
| Launch mass | 3,440 kg (7,580 lb) |
| Start of mission | |
| Launch date | 21 July 1973, 19:30:59 UTC |
| Rocket | Proton-K/D |
| Launch site | Baikonur 81/23 |
| Contractor | Khrunichev |
| End of mission | |
| Last contact | 10 February 1974, 15:38 UTC |
| Orbital parameters | |
| Reference system | Heliocentric |
| Perihelion altitude | 1.02 AU |
| Aphelion altitude | 1.63 AU |
| Inclination | 2.2° |
| Period | 556 days |
| Flyby of Mars (failed orbiter) | |
| Closest approach | 10 February 1974, 15:34 UTC |
| Distance | 1,844 km (1,146 mi) |
Mars 4 (Russian: Марс-4), also known as 3MS No.52S was a Soviet spacecraft intended to explore Mars. A 3MS spacecraft launched as part of the Mars programme, it was intended to enter orbit around Mars in 1974. However, computer problems prevented orbital insertion from occurring.