Soyuz 11: The Truth About the Salyut 1 Space Disaster

It is June 30 1971, and a ground crew in Kazakhstan are waiting to recover three cosmonauts from the Soyuz 11 spacecraft. The trio, the first space station crew, are expected to be unused to terrestrial gravity after their weeks in micro-gravity. The recovery team are expecting to help the spacefarers from the scorched re-entry module.  Little do they know however that they will be faced with a terrible sight, as the cosmonauts did not make it back to Earth alive. The three-man crew were made up of Vladislav Volkov, Georgi Dobrovolski and Viktor Patsayev and made history, not only for being the only human deaths to occur in space, but for a number of other reasons as well. Sinead McNicholl looks into the disaster.

Soyuz is a series of spacecraft designed for the Soviet space program by the Korolyov Design Bureau during the 1960s. In fact Soyuz is still the workhorse of the Russian space program today bringing cosmonauts and astronauts to the International Space Station. It was originally built as part of the Soviet manned lunar program, but America’s Apollo missions got there first with Neil Armstrong walking on the Moon in July 1969. After America had triumphed with their successful lunar landings, the USSR turned their attention to developing space stations.

The Soviets had launched the world’s first space station, Salyut 1, on 19 April 1971. The Russians had talked the talk about being able to dock with a space station, now they had to walk the walk! But when Soyuz 10 reached the space station and was unable to dock with it, the plans were put in place to launch Soyuz 11 on June 7, 1971. The mission reported no problems and successfully docked with Salyut 1 on June 7. Conquering the unknown and chalking up another ‘first’ in space history for Russia, the cosmonauts then went on to spend 22 days onboard the space station. This set a new record for space endurance, smashing the 13 days set by the US’s Gemini 7 in 1965 and the 18 days set by Soyuz 9 in 1970! Soyuz 11 would hold this mantle until the first American Skylab mission in 1973.

Image of Soyuz-11 patch

Mission Patch worn by the Soyuz 11 crew (Image credit:

The crew of Soyuz 11 had a productive stay onboard Salyut making live television broadcasts, communicating with Mission Control and even celebrated a birthday onboard when Patsayev turned 38 during the mission. The cosmonauts, as well as toasting the birthday boy with tubes of prune juice, also exercised onboard using a treadmill (which vibrated the entire station when in use) plus they cast votes from space when they affirmed their support for the Communist Party.

Image of Soyuz 11 Crew

Crew of the ill-fated Soyuz 11: (L-R) Patsayev, Dobrovolsky and Volkov. (Image credit: NASA)

Ready to return to Earth after the triumph of the mission, Commander Dobrovolsky reported that the undocking from the space station was successful, however what should have been a routine trip back to Earth proved not to be so. Upon re-entry nothing was heard from the capsule by Mission Control, however, the recovery team would have been unprepared for what they were presented with upon opening the capsule. The three-man crew were lifeless still strapped into their seats, and it became apparent that they had been asphyxiated. As the country mourned, the cosmonauts were given a large state funeral and buried in the Kremlin Wall in Moscow near the remains of Yuri Gagarin. The Soyuz craft was redesigned after this incident giving extra room for the cosmonauts to wear spacesuits onboard, which the crew of Soyuz 11 had not been able to do due to the lack of room. But what caused the capsule to lose pressure and why did the Soviets feel the need to try and hide the reasons behind the accident?

It was a joint venture between America and the USSR that would reveal the main causes for the Soyuz 11 disaster. Both countries were involved in the Apollo-Soyuz Test Project (ASTP) primarily as a symbol of the mid-70s policy of “détente” that the two superpowers were pursuing at the time. The venture would provide useful engineering experience for future joint US/Russian space flights, such as the Shuttle–Mir Program and the International Space Station. However, before America would get involved in the ASTP program a few outstanding questions would need to be addressed and one of those was the reason behind the ill-fated Soyuz 11 mission.

Image of Leonov and Slayton

Veterans of space Leonov and Slayton greet each other as the USSR and USA forge a space partnership during the Apollo-Soyuz Test Project. (Image credit:NASA)

After it happened, Soviet officials gave no explanation about the disaster except to say that the incident was being investigated by a government commission. Western space experts however began to speculate about what had happened. They believed that the Russians may have detected a failure onboard the craft and even thought that they knew the moment of death of the cosmonauts. Many theorised that the cosmonauts had exceeded man’s natural limitations in space and that weightlessness played a part in their deaths. But if weightlessness had played a part could that have accounted for all three of the men’s hearts stopping at the same time? Plus the cosmonauts had been in good heath on the space station and did not complain of any ill effects due to micro-gravity. Another theory was that the incident was a result of a mechanical fault either during or soon after the firing of the Soyuz’s retrorocket.

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The bus-sized space station Salyut 1 as pictured from the departing Soyuz 11 spacecraft. (Image credit:

Theories however were not going to help the Americans learn from the Russian’s mistakes, and during their preparations for the link up with the ASTP the truth was finally revealed. It was NASA’s Deputy Director, George Low, who in meetings with Russian Professor Bushuyev, uncovered the truth. Bushuyev detailed results from a post-flight investigation, experimental re-enactment of the mission and the steps that had been taken to make sure the failure would not happen again. So what had happened? Well, the cosmonauts perished due to their cabin depressurising. This occurred when a breathing ventilation value between the orbital module and the decent module opened during decent. This occurred approximately 723 seconds after retrofire. During separation, the 12 Soyuz pyro-cartridges (solid fuel rockets) fired together instead of sequentially and the huge force caused the mechanism of the pressure equalization valve to release. The value would have opened at a height of 168km and the gradual loss of pressure would have proved fatal to all onboard within thirty seconds.

The crew may have been aware of the problem due to the hissing noise that the leak produced. They perhaps tried to close the valve manually but would not have had enough time to get it closed as it was located beneath the seats. Flight data from the Cosmonaut fitted with biomedical sensors showed that cardiac arrest occurred within forty seconds of pressure loss. Footage, which was later declassified, showed how rescue teams attempted CPR on the Cosmonauts in vain. It also came to light that the valve was for fresh air and would only have been opened after landing.


Russia’s triumphant mission which had set new records for human endurance in space, proved that spacecrafts could dock with the space station, and re-energised the space in the minds of the Russian people had ended in tragedy. In Russia the cosmonauts were thought of as heroes as the entire nation grieved their deaths. American President Richard Nixon sympathized with Russia and led a tribute to the men and the families they left behind saying that had contributed to “the widening of man’s horizons”. After all the tragedy came only four years after the US Apollo 1 disaster when a cabin fire during a launch pad test killed three astronauts, Virgil “Gus” Grissom, Edward H. White and Roger B. Chaffee.

Image of Soyuz 11 Stamp

Being remembered (image credit:

The men who have risked their lived to widen our horizons are true heroes and should never be forgotten. They went into the unknown and paved the way for our advancement in space technology and science. However, we probably owe it to their memory to keep striving to achieve, to venture deeper into the unknown and travel further. Who knows, perhaps one day we might visit another planet and we should dedicate this to all those who have pointed us in the direction to reach for the stars!

Image of Sinead McNicholl

Sinead McNicholl, Education Support Officer (Image credit: Armagh Planetarium)

(Article by Sinead McNicholl)