Kosmos 300 (Ye-8-5 series) was the fourth Soviet attempt at an unmanned lunar

Moon

The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

 sample return. It was probably similar in design to the later Luna 16

Luna 16

-External links:*...

 spacecraft. It was launched, on a Proton rocket

Proton rocket

Proton is an expendable launch system used for both commercial and Russian government space launches. The first Proton rocket was launched in 1965 and the launch system is still in use as of 2011, which makes it one of the most successful heavy boosters in the history of spaceflight...

, on September 23, 1969. The mission was a failure. The engines on the Block D upper stage failed, leaving the spacecraft stranded in Earth orbit.

External links

• Zarya - Luna programme chronology