Kosmos 300
A Ye-8-5 model in the Museum of Cosmonautics, Moscow. | |
| Mission type | Lunar sample-return |
|---|---|
| Operator | Soviet space program |
| COSPAR ID | 1969-080A |
| SATCAT no. | 4104 |
| Mission duration | 4 days |
| Spacecraft properties | |
| Spacecraft type | Ye-8-5 |
| Manufacturer | GSMZ Lavochkin |
| Launch mass | 5,600 kg (12,300 lb) |
| Start of mission | |
| Launch date | September 23, 1969, 14:07:00 UTC |
| Rocket | Proton-K/D |
| Launch site | Baikonur 81/24 |
| End of mission | |
| Disposal | Launch failure |
| Decay date | September 27, 1969 |
| Orbital parameters | |
| Reference system | Geocentric |
| Perigee altitude | 184 km (114 mi) |
| Apogee altitude | 189 km (117 mi) |
| Inclination | 51.5° |
| Period | 88.2 min |
Kosmos 300 (Russian: Космос 300 meaning Cosmos 300) (Ye-8-5 series) was the fourth Soviet attempt at an uncrewed lunar sample return. It was probably similar in design to the later Luna 16 spacecraft. It was launched, on a Proton rocket, on September 23, 1969. The mission was a failure. The engines on the Block D upper stage failed due to an oxidizer leak, leaving the spacecraft to burn up in Earth's atmosphere.