1971 Soyuz-11 disaster

45 years ago, on June 30, 1971, the Soyuz-11 manned spacecraft crashed. The crew of Georgy Dobrovolsky, Vladislav Volkov and Viktor Patsaev died. The tragedy occurred during the return to Earth due to depressurization of the descent vehicle at high altitude. The design of the Soyuz did not provide for spacesuits for the crew.

The depressurization occurred due to the fact that during the separation of the compartments, the ventilation valve, designed to equalize the outboard atmospheric pressure with the pressure in the descent vehicle, opened prematurely. The astronauts discovered the opening of the valve, but did not have time to eliminate the accident.