Launch Date Sept. 23, 1969
Launch Site Baikonur Cosmodrome, Kazakhstan, Russia | Launch Site 81P
Destination Earth’s Moon
Type Lander, Sample Return
Status Unsuccessful
Nation Soviet Union
Alternate Names 1969-080A, 04104


This was the third Soviet attempt to bring samples of lunar soil back to Earth.


None. The spacecraft reached Earth orbit, but the booster failed to fire as needed to send the probe to the Moon. About four days after launch, it reentered Earth's atmosphere.

In Depth

This was the third attempt to send a sample-return spacecraft to the Moon (after failures in June and July 1969). On this attempt, the spacecraft successfully reached Earth orbit but failed to inject itself on a translunar trajectory.

Later investigation indicated that the Blok D upper stage had failed to fire a second time for translunar injection because of a problem with a fuel-injection valve that had become stuck during the first firing of the Blok D (for Earth orbital insertion). As a result, all the liquid oxygen in the Blok D was depleted. The Soviet press named the vehicle Kosmos 300 without alluding to its lunar goal. The payload's orbit decayed about four days after launch.


Launch Vehicle: Proton booster plus upper stage and escape stages, 8K82K + Blok D (Proton no. 244-01)

Spacecraft Mass: c. 5,700 kg

Spacecraft Instruments:

  1. stereo imaging system
  2. remote arm for sample collection
  3. radiation detector

Additional Resources

National Space Science Data Center Master Catalog: Kosmos 300

Selected References

Siddiqi, Asif A. Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, NASA, 2002.

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