29th June 1971: Soyuz 11 disaster causes the cosmonauts to become the only humans to die in space

Soyuz 11 was launched on June 6, and successfully docked with Salyut 1, the world’s first space station, the following day. The three-person crew of Georgi Dobrovolski, Viktor Patsayev, and Vladislav Volkov spent 23 days conducting a series of experiments and medical tests, marking a significant step forward in the space program.
On June 29, Soyuz 11 undocked from Salyut 1 to return to Earth. The descent appeared to be proceeding normally until contact was abruptly lost after the service module was jettisoned during the final stages of re-entry. Nevertheless recovery teams found the Soyuz 11 capsule on the ground after an automatic descent with no obvious outward damage, yet got no response from the crew inside.
Opening the hatch, they discovered all three cosmonauts dead, ‘with dark-blue patches on their faces and trails of blood from their noses and ears.’ Subsequent investigations revealed that a cabin vent valve had accidentally opened and depressurised the capsule when the service module was jettisoned at an altitude of 168 km (104 mi). The location of the valve made it impossible to block before a fatal loss of pressure. Without adequate pressure suits the crew fell unconscious and suffered cardiac arrest in less than a minute.
The Soyuz 11 disaster prompted an immediate investigation to improve safety measures for future missions, although the exact cause of death was not released for almost two years. Nevertheless the lessons learned from the tragic deaths of Dobrovolski, Patsayev, and Volkov mean that, despite other missions by both the USSR and the USA experiencing fatal disasters within the Earth’s atmosphere, the crew of Soyuz 11 are the only humans to have ever died in space.

[@DeTAYL.]

3 incredibly brave men. May they rest in peace

[@kylemarsh1624]

What a true shame. They tried to do something good and died from it. God Bless them and their families. Thank you, Gentlemen. God Bless 😊

[@otpyrcralphpierre1742]

Most safety regulations are written in Blood. RIP

[@johno9507]

The really macabre thing was 2 of the Soviet states released a postage stamp with a picture of the 3 obviously dead Cosmonauts still strapped into their spacecraft and ground personnel looking in.

[@nyckhusan2634]

There were 2 vent valves under the seats and they didn't know which one opened. They tried to close one and that was wrong. Anyway, they had only 20 sec to do it and as Leonov later determined ( he supposed to fly this ship as commander but team was changed by duplicate crew on last days before launch) it would take about one minute to close it manually, so they had no chance, unfortunately. during decompression event on the altitude of 168 km above Earth.

[@williamjones7163]

RIP Gentleman. You did not die in vain. God bless your souls and your families.

[@HailAnts]

The capsule was designed to hold two cosmonauts in their spacesuits. In order to fit three men into it the mission chiefs decided to forgo the suits..

[@danieloblinger1199]

The volume of this is much too low.

[@Anti-CornLawLeague]

But was it June 28th or 29th? What was the time zone in space?

[@historypod]

Missions use UTC / GMT for consistency. The jettison took place at 22:47 GMT.

[@bombonalvarez3802]

💐😥

[@JOESMITH-qs8ue]

Boeing. Hold my beer.

[@AlabamaMothman]

It took an incredibly brave man to get into that Russian junk and launch you into space inside of it.