Venera 11
Seal of Venera 11 | |
| Operator | Soviet Academy of Sciences |
|---|---|
| COSPAR ID | 1978-084A 1978-084D |
| SATCAT no. | 11020 11027 |
| Mission duration | Travel: 3 months and 16 days Lander: 95 minutes |
| Spacecraft properties | |
| Spacecraft | 4V-1 |
| Spacecraft type | 4V-1 No. 360 |
| Bus | 4MV |
| Launch mass | 4,447.3 kg (9,805 lb) |
| BOL mass | 4,715 kg (10,395 lb) |
| Landing mass | 760 kg (1,680 lb) |
| Dimensions | 2.7 m × 2.3 m × 5.7 m (8.9 ft × 7.5 ft × 18.7 ft) |
| Start of mission | |
| Launch date | September 9, 1978, 03:25:39 UTC |
| Rocket | Proton-K/D-1 8K82K |
| Launch site | Baikonur 81/23 |
| End of mission | |
| Last contact | February 1, 1980 |
| Orbital parameters | |
| Reference system | Geocentric |
| Regime | Low Earth |
| Semi-major axis | 6,569 kilometers (4,082 mi) |
| Eccentricity | 0.0312 |
| Perigee altitude | 177 kilometers (110 mi) |
| Apogee altitude | 205 kilometers (127 mi) |
| Inclination | 51.5° |
| Flyby of Venus | |
| Spacecraft component | Venera 11 flight platform |
| Closest approach | 25 December 1978 |
| Distance | ~35,000 kilometers (22,000 mi) |
| Venus lander | |
| Spacecraft component | Venera 11 descent craft |
| Landing date | 25 December 1978, 03:24 |
| Landing site | 14°S 299°E / 14°S 299°E (near Phoebe Regio) |
The Venera 11 (Russian: Венера-11 meaning Venus 11) was a Soviet uncrewed space mission which was part of the Venera program to explore the planet Venus. Venera 11 was launched on 9 September 1978 at 03:25:39 UTC.
Separating from its flight platform on December 23, 1978 the lander entered the Venus atmosphere two days later on December 25 at 11.2 km/s. During the descent, it employed aerodynamic braking followed by parachute braking and ending with atmospheric braking. It made a soft landing on the surface at 06:24 Moscow Time (03:24 UT) on 25 December after a descent time of approximately 1 hour. The touchdown speed was 7 to 8 m/s. Information was transmitted to the flight platform for retransmittal to Еarth until it moved out of range 95 minutes after touchdown. Landing coordinates are 14°S 299°E / 14°S 299°E.