Although the 3MV-3 and 3MV-4 type spacecraft were originally intended for Mars exploration, the Soviets re-equipped three of the series, left over from the 1964 Mars launch periods, for Venus exploration in 1965.

This particular vehicle was scheduled to fly past the sunlit side of Venus at no more than 24,855 miles (40,000 kilometers) and to take photographs. About 3 hours after injection into heliocentric orbit, contact was temporarily lost with the spacecraft, and although it was regained soon after, the event was symptomatic of the mission in general during which communications were generally poor.

Before closest approach in late Feb. 1966, ground control switched on all the onboard scientific instrumentation. Closest approach to the planet was at 02:52 UT on Feb. 27, 1966 at about 15,000 miles (24,000 kilometers) range.

After its flyby, when the spacecraft was supposed to relay back the collected information, ground control was unable to regain contact. Controllers finally gave up all attempts at communication on March 4, 1966.

Venera 2 eventually entered heliocentric orbit. Later investigation indicated that improper functioning of 40 thermal radiator elements caused a sharp increase in gas temperatures in the spacecraft. As a result, elements of the receiving and decoding units failed (and the solar panels overheated), and contact was lost. Ironically, the scientific instruments may have collected valuable data, but none of it was ever transmitted back to Earth.


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

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