Mission Type: Sample Return
Launch Vehicle: Proton booster plus upper stage and escape stages, 8K82K + Blok D (Proton no. 244-01)
Launch Site: Tyuratam (Baikonur Cosmodrome), USSR, NIIP-5 / launch site 81P
Spacecraft Mass: c. 5,700 kg
Spacecraft Instruments: 1) stereo imaging system, 2) remote arm for sample collection and 3) radiation detector
Spacecraft Dimensions: Four spherical fuel tanks and nozzles, thrusters, and landing legs set in a 4-meter-wide base.
References:
Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, Monographs in Aerospace History No. 24, by Asif A. Siddiqi

National Space Science Data Center, http://nssdc.gsfc.nasa.gov/

Solar System Log by Andrew Wilson, published 1987 by Jane's Publishing Co. Ltd.

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.