A rocket malfunction prevented this Venus-bound mission from leaving Earth orbit. It fell back to Earth three days after launch.


This was the first in a second generation of Soviet deep space probes based on a unified platform called 2MV (“2” for the second generation, “MV” for Mars and Venera) designed to study Mars and Venus.

The series included four variants with the same bus, but with different payload complements: 2MV-1(for Venus impact), 2MV-2 (for Venus flyby), 2MV-3 (for Mars impact), and 2MV-4 (for Mars flyby). The buses were basically similar in design, carrying all the essential systems to support the mission as well as a main engine, the S5.17 on the two Venus probes, and the S5.19 on the Mars probes. Both had a thrust of 441 pound-force (200 kilogram-force), but the former was capable of one firing while the latter was designed for two.

The payloads were designed in two variants depending on whether the mission was a flyby mission or an impact mission. In the former, there was an instrument module, and in the latter, it carried a 35 inch (90 centimeter) diameter spherical pressurized lander covered by thermal coating. The Venus landers were cooled with an ammonia-based system, while the Mars landers used a system of air conditioners. Both landers were sterilized with a special substance on recommendation from the Academy of Sciences’ Institute of Microbiology. The buses were powered by solar panels with an area of 27 square feet (2.5 square meters) capable of providing 2.6 A.

The Venus impact probes were to use a three-stage parachute system to descend through the atmosphere. For Venus, the Soviets prepared three spacecraft for the Aug.-Sept. 1962 launch period, one flyby spacecraft and two landers.

This first spacecraft -- a flyby plus lander combination -- was successfully launched into Earth orbit, but the Blok L upper stage cut off its interplanetary burn after only 45 seconds (instead of the planned 240 seconds).

Later investigation showed that the stage had been set on a tumbling motion prior to main engine ignition due to asymmetrical firing of the solid propellant stabilizing motors. The spacecraft remained in Earth orbit for three days before reentering Earth’s atmosphere.


Siddiqi, Asif A. Beyond Earth: A Chronicle of Deep Space Exploration, 1958-2016. NASA History Program Office, 2018.

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