Goals: Like its twin, which was unsuccessfully launched six days earlier, this Soviet spacecraft was intended to orbit Mars.
Accomplishments: None. One of the first-stage engines exploded on launch and the rocket carrying the probe crashed in a fireball 3 km from the launch site.
2 Apr 1969: Launch
8K82K + Blok D (Proton no. 233-01)
NIIP-5 / launch site 81P
about 3,800 kg
1) radiometer; 2) instrument to measure water vapor levels; 3) ultraviolet spectrometer; 4) radiation detector; 5) gamma spectrometer; 6) hydrogen/helium mass spectrometer; 7) spectrometer; 8) low-energy ion spectrometer and 9) imaging system (three cameras)
Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, Monographs in Aerospace History No. 24, by Asif A. Siddiqi
Solar System Log by Andrew Wilson, published 1987 by Jane's Publishing Co. Ltd.
The second M-69 spacecraft was identical to its predecessor (launched six days before) and was intended to enter orbit around Mars on 15 September 1969. Like its twin, it never reached intermediate Earth orbit.
During launch, at T+0.02 seconds, one of the six first-stage engines of the Proton exploded. Although the booster lifted off using the remaining five engines, it began veering off course and eventually assumed horizontal attitude, at which point all the remaining first-stage engines shut down. At T+41 seconds, the booster impacted the ground 3 kilometers from the launch site in a massive fireball.