| Kosmos 305 | |
| Operator: | Soviet space program |
| Cospar Id: | 1969-092A |
| Satcat: | 4150 |
| Spacecraft Type: | Ye-8-5 |
| Manufacturer: | GSMZ Lavochkin |
| Launch Mass: | 5600kg (12,300lb)[1] |
| Launch Date: | UTC[2] |
| Launch Rocket: | Proton-K/D |
| Launch Site: | Baikonur 81/24 |
| Disposal Type: | Launch failure |
| Decay Date: | October 24, 1969 |
| Orbit Reference: | Geocentric |
| Orbit Periapsis: | 1820NaN0 |
| Orbit Apoapsis: | 2080NaN0 |
| Orbit Inclination: | 51.4° |
| Orbit Period: | 88.4 min |
| Apsis: | gee |
| Programme: | Luna programme |
| Previous Mission: | Kosmos 300 |
| Next Mission: | Luna 1970A |
| Programme2: | Kosmos (satellites) |
| Previous Mission2: | Kosmos 304 |
| Next Mission2: | Kosmos 306 |
Kosmos 305 (Russian: Космос 305 meaning Cosmos 305) (Ye-8-5 series) was the fifth Soviet attempt at an uncrewed lunar sample return. It was probably similar in design to the Luna 16 spacecraft. It was launched, on a Proton rocket, on October 22, 1969.[3] The engines on the Block D upper stage failed, terminating the mission. This left the spacecraft stranded in Earth orbit. It re-entered within two days.[4]