Mission Type: Flyby
Launch Vehicle: 8K78 (no. G103-18)
Launch Site: Tyuratam (Baikonur Cosmodrome), U.S.S.R., NIIP-5 / launch site 1
Spacecraft Mass: c. 800 kg
Spacecraft Instruments: 1) radiation detector; 2) charged-particle detector; 3) magnetometer; 4) piezoelectric detector; 5) atomic hydrogen detector; 6) radio telescope; 7) ultraviolet and Roentgen solar radiation experiment; 8) technology experiment and 9) plasma engines
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/

This was the first of the Soviet Union's "third-generation" deep space planetary
probes of the 3MV series. Like the second generation, Soviet engineers projected four types of the 3MV: the 3MV-1 (for Venus impact), 3MV-2 (for Venus flyby), 3MV-3 (for Mars impact), and 3MV-4 (for Mars flyby). The primary difference over the second generation was vastly improved (and in many cases doubled) orientation system elements.

While these four versions were meant to study Mars and Venus, the Soviets conceived of two additional variants of the series, similar but not identical to the 3MV-1 and 3MV- 4 versions. These "test variants" were designed to verify key technological systems during simpler missions on flyby missions to the Moon and the near planets.

On this particular launch, the first to fly a "test variant," the third and fourth stages separated abnormally; after the craft reached Earth orbit, ground control lost telemetry from the Blok L upper stage designed to send the vehicle past
the Moon. The stage's main engine turbopump probably exploded upon ignition,
destroying the payload.

With this mission, the Soviets began the practice of giving Kosmos designations to lunar and planetary probes that remained stranded in Earth orbit.