Mission Type: Flyby
Launch Vehicle: 8K82K + Blok D (Proton-Kno. 230-01 / Blok D no. 13L)
Launch Site: NIIP-5 / launch site 81P
Spacecraft Mass: c. 5,375 kg
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.
This was the second Soviet attempt at a robotic circumlunar mission. On this launch, one of the four second-stage engines of the Proton rocket failed to ignite at T+125.5 seconds due to a break in the engine nozzle.
The wayward booster was then destroyed on command from the ground at T+129.9 seconds.