Luna 18
 A Ye-8-5 model in the Museum of Cosmonautics, Moscow. | |
| Mission type | Lunar sample return |
|---|---|
| Operator | Soviet space program |
| COSPAR ID | 1971-073A |
| SATCATno. | 5448 |
| Mission duration | 9 days (launch day to day of last contact) |
| Spacecraft properties | |
| Bus | Ye-8-5 |
| Manufacturer | GSMZ Lavochkin |
| Launch mass | 5,725 kilograms (12,621 lb)[1] |
| Dry mass | 5,600 kilograms (12,300 lb)[citation needed] |
| Start of mission | |
| Launch date | 2 September 1971, 13:40:40UTC[1] |
| Rocket | Proton-K/D |
| Launch site | Baikonur81/24 |
| End of mission | |
| Last contact | 11 September 1971, 07:48UTC |
| Orbital parameters | |
| Reference system | Selenocentric |
| Eccentricity | 0.001361 |
| Periselene altitude | 1,824.9 kilometres (1,133.9 mi) |
| Aposelene altitude | 1,842.3 kilometres (1,144.8 mi) |
| Inclination | 35 degrees |
| Period | 119 minutes |
| Epoch | 6 September 1971, 20:00:00 UTC[2] |
| Lunarorbiter | |
| Orbital insertion | 7 September 1971 |
| Orbits | ~48 |
| Lunar impact(failed landing) | |
| Impact date | 11 September 1971 07:48 UTC |
| Impact site | 3°34′N56°30′E/ 3.567°N 56.500°E |
| Instruments | |
| Stereo photographic imaging system Remote arm for sample collection Radiation detector Radio altimeter | |
Luna 18,part of the Ye-8-5 series, was anuncrewed space missionof theLuna program.
Overview[edit]
Luna 18was placed in an Earth parking orbit after it was launched and was then sent towards the Moon. On 7 September 1971, it entered lunar orbit. The spacecraft completed 85 communications sessions and 54 lunar orbits before it was sent towards thelunar surfaceby use ofbraking rockets.It impacted the Moon on 11 September 1971, at 3 degrees 34 minutes N, 56 degrees 30 minutes E (selenographic coordinates) in rugged mountainous terrain. Signals ceased at the moment of impact.
This mission was the seventh Soviet attempt torecover soil samplesfrom the surface of the Moon and the first after the success ofLuna 16.After two mid-course corrections on 4 September and 6 September 1971,Luna 18entered a circular orbit around the Moon on 7 September at 100 kilometers altitude with an inclination of 35°. After several more orbital corrections, on 11 September, the vehicle began its descent to the lunar surface. Contact with the spacecraft was lost at 07:48 UT at the previously determined point of lunar landing. Impact coordinates were 3°34' north latitude and 56°30' east longitude, near the edge of theMare Fecunditatis( "Sea of Fertility" ). Officially, the Soviets announced that "the lunar landing in the complex mountainous conditions proved to be unfavorable." Later, in 1975, the Soviets published data fromLuna 18's continuous-wave radio altimeter that determined the meandensityof thelunar topsoil.
See also[edit]
References[edit]
- ^abSiddiqi, Asif (2018).Beyond Earth: A Chronicle of Deep Space Exploration, 1958–2016(PDF)(second ed.). NASA History Program Office.ISBN9781626830431.
- ^"NASA - NSSDCA - Spacecraft - Trajectory Details".nssdc.gsfc.nasa.gov.Retrieved2018-05-02.
