The Mir Space Station: History and Legacy

Mir was a space station that was operated in Low Earth Orbit (LEO) from 1986 to 2001 by the Soviet Union and then by Russia. Predecessor of the International Space Station, the Mir station was the first continuously inhabited long-term research station in orbit.

The former director of the Shuttle-Mir program, Franck L. Culbertson, said in 1996 that the term “mir” represents a community “with common goals and values in a place where they had a better chance of surviving, living a productive life and succeeding as a group” and it described perfectly the purpose of Mir.

The history of Mir

Mir was the next step of the Soviet Union’s space exploration program after the success of Salyut which was the first space station program, running from 1971 to 1986. It was structured around the launches of several successive stations: Salyut 1, the world’s first space station was launched in 1971, followed two years later by Salyut 2 which unfortunately suffered an explosion after being placed in orbit and was never occupied. The program was designed to pursue both military goals – launch of Salyut 3 and 5 – and scientific purposes – launch of Salyut 6 and 7. Each station bringing its share of technical improvements, the Salyut program, literally salute in Russian, in tribute of Yuri Gagarin’s exploits, paved the way for Mir and the International Space Station (ISS).

It was in 1976 that Mir was authorised by decree. The project was to design an improved model of the Salyut space stations. In 1979, it was decided that the Mir program was to be merged with the Almaz military space station program. But it almost did not happened since in early 1984 its advancement was halted and all funding was entirely directed to the Buran spacecraft flight tests. Fortunately Valentin Glushko, who had been ordered to put Mir into orbit for 1986, finally decided to redistribute funding to the station.

One of Mir’s important progress, compared to the Salyut station, was the plurality of mooring ports on the station, thus allowing the docking of several spacecrafts at the same time and therefore an easier relief between crews and supplies, allowing longer stays in space.

At the time, Mir was a revolutionary station since it consisted of several habitable modules. There was a central module, from Salyut 7, and then five other scientific modules from the Almaz science program. Finally, a seventh module was added in 1995 for the docking of the American space shuttle. Due to the political and economic context of the late 1980s and 1990s, the assembly of the different modules of the station had been significantly delayed. Indeed the station will not be fully operational before 1996, ten years after the launch of the station’s first module.

The purpose of having several modules was to assign a specific role to each of them. Thus in the Mir station, the central module was mainly used as the living quarters of the crew whereas the other modules were dedicated to different scientific areas. For example, the module Kvant-1 was dedicated to astrophysics, whereas the module Kristall was dedicated to technology.

The aims of Mir

The main objective of the station was to develop and test technologies that would be needed for permanent space occupation. The possibility Mir offered to make long stays in space helped understand the difficulties faced when a permanent presence in space is established and especially the effects on the human body and mind. The station still holds the record for the longest single human spaceflight: Valeri Polyakov spend 437 days and 18 hours on the station between 1994 and 1995 so as to demonstrate that a human body can stay in micro-gravity for a period of time equivalent to the one that would be needed to go to Mars.

Accordingly to the aim of the station, it served as a microgravity research laboratory in which the different crews performed experiments in biology, human biology, physics, astronomy, meteorology and spacecraft systems.

Given that the aim of the experiments hosted was to develop ways of sustaining life in space, the station raised wheat, the first crop to be grown from seed to seed in outer space. The experiments were designed to answer vital questions about how humans, animals and plants would function in space, about how our solar system originated and developed, about how we can build better technology in space and about how we can build future space stations.

The Shuttle-Mir program

Thanks to the Mir station, the Russians and the Americans learned to work together, despite the geopolitical context of the time. The beginnings of an American-Russian cooperation date back to the 1960s, even if the two countries were engaged in a merciless race to conquer the moon. At the time U.S. President John F. Kennedy and Soviet head of state Nikita Khrushchev began to discuss future ways of cooperation and in 1964 they agreed to exchange information on space biology and medicine. But the first major step was in the 1970s with the Apollo-Soyuz project.

Even in the midst of the cold war, cooperation between the two countries continued and in 1992, the United States and Russia renewed the 1987 space cooperation agreement and issued a “Joint statement on Cooperation in Space“.

Since the economic and political context was not the most favorable to the development of space activities, NASA and Roscosmos understood the need to cooperate together if they wanted to pursue the development of their own activities.

It was decided in the “Joint statement on Cooperation in Space” that the cooperation would include a “Space Shuttle and Mir Space Station mission involving the participation of U.S astronauts and Russian cosmonauts“. Thus from February 1994 to June 1998, the American space shuttle made 11 flights to Mir and the American astronauts spent 7 residencies onboard Mir.

Accidents on board of the station

The history of the Mir space station has been marked by two of the most impressive accidents that ever happened in space.

The first one occurred on February 23, 1997. An oxygen generator caught fire when it was replaced. Fire is one of the most serious disasters that can occur on board of a space station. Indeed the astronauts cannot leave the station and because of its small size, the fire can spread everywhere at an impressive speed. The station can be quickly invaded by smoke and toxic products. Russian authorities had said the fire lasted for less than two minutes but the U.S astronauts on board explained that the fire continued for at least fourteen minutes. In addition the smoke release by the fire had blocked the passage to a Soyuz capsule which would have allowed the astronauts to escape. Eventually the crew managed to extinguish the fire with a wet towel and a fire extinguisher. This accident definitely changed the engineering standards for space as well as emergency procedures.

The second one happened on June 27, 1997 when the Progress cargo spaceship collided with the Spektr module while docking. A new mooring system was apparently in the process of being tested and it appears that the cargo spaceship got out of their control. The collision resulted in a three square centimeter hole in the shell that isolates the module from the vacuum of space and also caused damage to the solar panels. This crack caused the depressurization of the module which was used as the sleeping quarters for the astronauts as well as a laboratory for the Americans.

Astronaut Michael Foale was inside the module when the crash occurred. He says he felt a slight shock and then after feeling a pressure in his ears, he immediately understood that the module was depressurizing and therefore came out directly from it. Consequently the crew had to permanently seal the Spektr module and turn off some of the equipment to conserve as much energy as possible since solar panels were damaged.

These two accidents allowed lessons to be learned on the issue of fire and depressurisation risks. It was therefore decided that the alarm systems had to be more efficient and that the astronauts had to be trained more rigorously in the emergency procedures to be followed. Lessons on improvements to the design of a space station have also been learned and have been directly applied to the ISS.

The legacy of the Mir space station

The station was deorbited in March 2001 for several reasons. First of all, funding were cut off: Russia had decided to participate to the International Space Station program in 1993 and couldn’t afford to finance both projects. Moreover the station was getting older and the components were no longer suited to the needs of the astronauts.

The deorbiting procedure was carried out in two main stages: first, the station’s thrusters had to be used to slow it down and put it in a sufficiently low orbit so that it was again strongly attracted by terrestrial gravity. Then the station gradually disintegrated in the atmosphere. The remaining twenty tons from the station fell into the Pacific Ocean.

The Mir station has left an important legacy: thanks to the trials and errors committed during its use, we have been able to develop techniques that are more and more precise and adapted to human life in space. Thanks to the Mir station, all the knowledge acquired was directly applied to the design of the ISS.

Under the aegis of Mir, a real scientific partnership between nations, even though rivals on Earth, has emerged.