Georgy Dobrovolsky, Vladislav Volkov and Viktor Patsayev had spent 23 days aboard Salyut 1, a record at the time. As the descent module separated from the rest of the spacecraft, a valve jolted open and the cabin depressurized within seconds. The crew wore no pressure suits. The capsule landed normally, and the recovery team opened the hatch to find the men dead in their seats. After the disaster, Soviet crews always wore spacesuits for launch and landing.
Soyuz 11 launched on June 6, 1971, and docked with Salyut 1 the next day, after an earlier crew had failed to get aboard. The three men conducted experiments, broadcast television reports and became national heroes. Their stay was not easy: a small fire broke out, and the station was cramped. They undocked on June 29.
In the early hours of June 30, Moscow time, explosive bolts fired to separate the descent module. The shock opened a pressure-equalization valve designed to open only near the ground. Air began rushing out. Investigators concluded that the crew tried to close the valve by hand, but it took far longer to shut than the seconds they had. They lost consciousness within about a minute.
The automated landing worked perfectly. When rescuers opened the hatch, they found the cosmonauts without signs of injury. The Soviet Union held a state funeral, and the men were buried in the Kremlin Wall. The Soyuz was redesigned to carry two cosmonauts in suits, and crewed flights did not resume for more than two years.
Key people: Georgy Dobrovolsky, Vladislav Volkov, Viktor Patsayev