Soyuz 11

The descent module came down exactly where and how it should have on 30 June 1971, parachute deployed, hull intact on the Kazakh steppe about 500 kilometres east of Dzhezkazgan. Recovery crews found the capsule outwardly undamaged and opened the hatch to silence. Inside, Georgi Dobrovolski, Vladislav Volkov and Viktor Patsayev were still strapped in their couches. Attempts at resuscitation failed. The three men had just completed the longest spaceflight in history, and they had been dead since shortly after leaving orbit.

They were not even supposed to fly. Two days before launch, doctors found a suspicious spot on prime crew member Valery Kubasov's chest X-ray, and the entire backup crew was moved up in their place. Launched on 6 June 1971, they docked with Salyut 1 the next day and became the first crew ever to live aboard a space station. Over more than three weeks they shattered the 18-day endurance record, and Patsayev became the first person to operate a telescope in space and the first to mark a birthday there, turning 38 on 19 June.

The journey home began normally on the night of 29 June. Then, at module separation around 168 kilometres altitude, the simultaneous firing of explosive bolts jarred open a pressure equalization valve meant to stay closed until the final parachute descent. The cabin's air vented to space in under a minute, and the crew, flying without pressure suits because the cramped Soyuz of 1971 had no room for them with three aboard, lost consciousness within about two minutes. The automated systems flew the reentry and landing flawlessly, bringing home a capsule that could no longer be saved.

The Soviet Union honored the three cosmonauts with a state funeral on Red Square, their ashes interred in the Kremlin Wall, with NASA astronaut Thomas Stafford among those representing the United States. Crewed Soyuz flights halted for over two years while engineers rebuilt the spacecraft for two cosmonauts wearing pressure suits, and no Soyuz crew has flown unsuited through launch or landing since. Dobrovolski, Volkov and Patsayev remain the only human beings to have died in space itself, above the Kármán line.