Soyuz 11: Disaster in Space

Soyuz 11
A TASS/Soviet Space agency image of the three Soyuz 11 astronauts in training for their ill-fated mission. TASS

Space exploration is dangerous. Just ask the astronauts and cosmonauts who do it. They train for safe space flight and the agencies who send them to space work very hard to make conditions as safe as possible. Astronauts will tell you that while it looks like fun, space flight is (like any other extreme flight) comes with its own set of dangers. This is something the crew of Soyuz 11 found out too late, from a small malfunction that ended their lives.

 

A Loss for the Soviets

Both American and Soviet space programs have lost astronauts in the line of duty. The Soviets' biggest major tragedy came after they lost the race to the Moon. After the Americans landed Apollo 11 on July 20, 1969, the Soviet space agency turned its attention towards constructing space stations, a task they became quite good at, but not without problems. 

Their first station was called Salyut 1 and was launched on April 19, 1971. It was the earliest predecessor for the later Skylab and the current International Space Station missions. The Soviets built Salyut 1 primarily to study the effects of long-term space flight on humans, plants, and for meteorological research. It also included a spectrogram telescope, Orion 1, and gamma-ray telescope Anna III. Both were used for astronomical studies. It was all very ambitious, but the very first crewed flight to the station in 1971 ended in disaster.

A Troubled Beginning

Salyut 1’s first crew launched aboard Soyuz 10 on April 22, 1971. Cosmonauts Vladimir Shatalov, Alexei Yeliseyev, and Nikolai Rukavishnikov were aboard. When they reached the station and attempted to dock on April 24, the hatch would not open. After making a second attempt, the mission was canceled and the crew returned home.

Problems occurred during reentry and the ship’s air supply became toxic. Nikolai Rukavishnikov passed out, but he and the other two men recovered fully.

The next Salyut crew, scheduled to launch aboard Soyuz 11, were three experienced fliers: Valery Kubasov, Alexei Leonov, and Pyotr Kolodin. Prior to launch, Kubasov was suspected of having contracted tuberculosis, which caused the Soviet space authorities to replace this crew with their backups, Georgi Dobrovolski, Vladislav Volkov and Viktor Patsayev, who launched on June 6, 1971.

A Successful Docking

After the docking problems that Soyuz 10 experienced, the Soyuz 11 crew used automated systems to maneuver within a hundred meters of the station. Then they hand-docked the ship. However, problems plagued this mission, too. The primary instrument aboard the station, the Orion telescope, would not function because its cover failed to jettison. The cramped working conditions and a personality clash between the commander Dobrovolskiy (a rookie) and the veteran Volkov made it very difficult to conduct experiments. After a small fire flared up, the mission was cut short and the astronauts departed after 24 days, instead of the planned 30. Despite these problems, the mission was still considered a success.

Disaster Strikes

Shortly after Soyuz 11 undocked and made an initial retrofire, communication was lost with the crew far earlier than normal. Usually, contact is lost during the atmospheric re-entry, which is to be expected. Contact with the crew was lost long before the capsule entered the atmosphere. It descended and made a soft landing and was recovered on June 29, 1971, 23:17 GMT. When the hatch was opened, rescue personnel found all three crew members dead.  What could have happened?

Space tragedies require thorough investigation so that mission planners can understand what happened and why. The Soviet space agency's investigation showed that a valve which was not supposed to open until an altitude of four kilometers was reached had been jerked open during the undocking maneuver. This caused the cosmonauts' oxygen to bleed into space.

The crew tried to close the valve but ran out of time. Due to space limitations, they were not wearing space suits. The official Soviet document on the accident explained more fully: 

"At approximately 723 seconds after retrofire, the 12 Soyuz pyro cartridges fired simultaneously instead of sequentially to separate the two modules .... the force of the discharge caused the internal mechanism of the pressure equalization valve to release a seal that was usually discarded pyrotechnically much later to adjust the cabin pressure automatically. When the valve opened at a height of 168 kilometers the gradual but steady loss of pressure was fatal to the crew within about 30 seconds. By 935 seconds after retrofire, the cabin pressure had dropped to zero...only thorough analysis of telemetry records of the attitude control system thruster firings that had been made to counteract the force of the escaping gases and through the pyrotechnic powder traces found in the throat of the pressure equalization valve were Soviet specialists able to determine that the valve had malfunctioned and had been the sole cause of the deaths."

The End of Salyut

The USSR did not send any other crews to Salyut 1. It was later deorbited and burned up on reentry. Later crews were limited to two cosmonauts, to allow room for the required space suits during take-off and landing. It was a bitter lesson in spacecraft design and safety, for which three men paid with their lives. 

At latest count, 18 space fliers (including the crew of Salyut 1) have died in accidents and malfunctions.

As humans continue to explore space, there will be more deaths, because space is, as the late astronaut Gus Grissom once pointed out, a risky business. He also said that the conquest of space is worth the risk of life, and people in space agencies around the world today recognize that risk even as they seek to explore beyond Earth.

Edited and updated by Carolyn Collins Petersen.