Conduct of further scientific investigation of the moon and circumlunar space. Failed lunar soil return mission. The sample collecting apparatus could not operate and no samples were returned. The lander continued transmissions for three days after landing. In 1976, Luna 24 landed several hundred meters away and successfully returned samples.
Parameters are for lunar orbit.
Block D failure. Attempted robotic lunar soil return mission. Block D stage failed. Lunar Sample Return. The mission successfully returned 170 grams of lunar samples to the Earth on 22 August 1976.