Launch Date Oct. 22, 1969
Launch Site Baikonur Cosmodrome, Kazakhstan, Russia
Destination Earth’s Moon
Type Lander, Sample Return
Status Unsuccessful
Nation Soviet Union
Alternate Names 1969-092A, 04150


Following the failed Kosmos 300 mission, Kosmos 305 was launched with the same goal: to retrieve lunar soil samples and bring them to Earth.


None. The rocket that was to propel the probe from Earth orbit to the Moon failed to fire, and the spacecraft reentered the atmosphere after it had completed less than one orbit of the Earth.

Key Dates

Oct. 22, 1969: Launch

In Depth

Exactly one lunar month after the failure of Kosmos 300, the Soviets launched another Ye-8-5 lunar sample-return spacecraft. Once again, the spacecraft failed to leave Earth orbit.

When the Blok D upper stage was meant to fire for translunar injection, telemetry readings went off-scale and communications were lost. There had apparently been a programming failure in one of the radio-command blocks designed to command the Blok D to fire.

The Soviet press merely referred to the probe as Kosmos 305. The spacecraft's orbit decayed over Australia before the craft completed a single orbit of Earth.


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 305

Selected References

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

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