Mission Type: Lander, Sample Return
Launch Vehicle: 8K82K + Blok D (Proton no. 238-01)
Launch Site: NIIP-5 / launch site 81P
Spacecraft Mass: about 5700 kg
Spacecraft Instruments: 1) stereo imaging system; 2) remote arm for sample collection and 3) radiation detector
Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, Monographs in Aerospace History No. 24, by Asif A. Siddiqi
The Ye-8-5 was a variant of the basic Ye-8 lunar-rover spacecraft developed by the Lavochkin design bureau. This particular version, whose development began in 1968, was designed to recover a small portion of soil from the lunar surface and return it to Earth.
It had the same basic lander stage ("KT") as that of the rover variant (built around a structure comprising four spherical propellant tanks linked together in a square), which was installed with a robot arm to scoop up lunar soil. The rover was replaced by a new "ascent stage" that was built around three spherical propellant tanks that consisted of a main rocket engine to lift off from the Moon, a pressurized compartment for electronics, and a small, 39-kilogram spherical capsule that would detach from the stage and reenter Earth's atmosphere with its valuable payload of lunar dust.
On the first launch attempt of the Ye-8-5 robot scooper, the first three stages of the Proton worked without fault, but the Blok D fourth stage, which was to fire to attain orbital velocity, failed to ignite due to a disruption in the circuit of its guidance system. The spacecraft reentered Earth's atmosphere over the Pacific without reaching orbit.