Fifty-five years later, an account by NASA historian John Uri<\/a> explains how the capsule landed normally with no one alive inside.<\/p>\n\n\n\n Late on June 29, the crew closed the hatch to Salyut and undocked. A warning light suggested the hatch to the descent module had not sealed. Ground control talked them through cleaning the seals, and the light stayed on, but everyone agreed the hatch was closed.<\/p>\n\n\n\n After three more orbits, Dobrovolski turned the spacecraft backward and fired its retrorocket for 187 seconds. Nine minutes later, at about 80 miles (129 kilometers), explosive bolts split the Soyuz into three modules. The crew sat in the bell-shaped descent capsule, the part built for reentry that engineers still test today with small capsules and experimental heat shields<\/a>.<\/p>\n\n\n\n That shock jarred open a pressure equalization valve. It was meant to let outside air in only once the capsule hung from its parachute, well inside the atmosphere. Instead it opened to the vacuum of space, and NASA says the air “escaped in less than one minute.”<\/p>\n\n\n\n According to NASA, there is evidence the cosmonauts tried to close the valve by hand. That job took several minutes. They lost consciousness as the pressure dropped and died within two minutes, about 30 minutes before landing, with no pressure suits on.<\/p>\n\n\n\n The capsule finished its reentry in fully automatic mode. On the ground, the only worry was the silence on the radio.<\/p>\n\n\n\n Its parachute opened as planned. Rescue helicopters set down beside the capsule as it landed softly 320 miles (515 kilometers) east of the city of Zhezkazgan. Resuscitation attempts by the recovery team failed.<\/p>\n\n\n\n Soviet capsules had already brought living passengers home from far beyond Earth orbit, including two steppe tortoises that flew around the Moon in 1968<\/a>. None of that experience covered a valve popping open at the wrong moment.<\/p>\n\n\n\n On April 19, 1971, the Soviet Union launched Salyut, the world’s first space station. NASA’s history office says it weighed 40,620 pounds (about 18,400 kilograms). Inside were 2,600 pounds of scientific gear, including telescopes and instruments to observe the Earth.<\/p>\n\n\n\n That habit of watching the planet from orbit continues today, as the photos a NASA astronaut takes from the space station<\/a> show. Back in 1971, an earlier crew on Soyuz 10 reached Salyut but could not get inside because of a docking problem.<\/p>\n\n\n\n Soyuz 11 launched on June 6 and docked manually the next day. Patsayev became the first person to float into a space station.<\/p>\n\n\n\n For three weeks the crew grew Chinese cabbage and onions, ran on a treadmill and drew blood samples. Patsayev operated the Orion-1 ultraviolet instrument, the first telescope run by a person in space. On June 19 he turned 38, the first birthday celebrated in space.<\/p>\n\n\n\n A small electrical fire smoldered at the rear of the station on June 16, an incident Moscow never mentioned at the time. Five days after the birthday, they beat the 18-day endurance record set by Soyuz 9. The NASA history of Salyut<\/a> calls it a then record-setting 24-day mission.<\/p>\n\n\n\n Dobrovolski, Volkov and Patsayev were the backup crew. Three days before launch, during a preflight physical at the Baikonur Cosmodrome, doctors spotted a dark spot on Valeri Kubasov’s chest X-ray, and flight surgeons grounded him over fears of tuberculosis.<\/p>\n\n\n\n Managers then argued over swapping out only Kubasov or his crewmates Aleksei Leonov and Pyotr Kolodin too, a debate NASA’s historian compares to the days before Apollo 13. Soviet rules settled it: once at Baikonur, a crew was replaced as a whole. Kubasov never had tuberculosis, physicians later concluded.<\/p>\n\n\n\n After the accident, the Soviets paused human flights while engineers redesigned the Soyuz. NASA notes that since then, all cosmonauts have worn spacesuits during Soyuz launches and landings.<\/p>\n\n\n\nA valve opened 80 miles up<\/h2>\n\n\n\n
A soft landing in Kazakhstan<\/h2>\n\n\n\n
![\"Soyuz](\"https:\/\/www.ecoticias.com\/en\/wp-content\/uploads\/2026\/10\/m1-descent-capsule-kazakhstan-landing.jpg\")
Three weeks aboard Salyut<\/h2>\n\n\n\n
![\"Viktor](\"https:\/\/www.ecoticias.com\/en\/wp-content\/uploads\/2026\/10\/m2-patsayev-orion-telescope-salyut.jpg\")
A dark spot on an X-ray<\/h2>\n\n\n\n
Pressure suits on every Soyuz<\/h2>\n\n\n\n