Mir Space Station (1986-2001): Soviet and Russian Outpost

Mir was a Soviet and later Russian space station whose core module was launched on 20 February 1986 and which remained in orbit until it was deliberately brought down on 23 March 2001. Built from seven modules joined in space, it was the first modular space station and was occupied almost continuously for a decade. Mir set records for long-duration spaceflight, survived serious accidents and became a meeting place for Russian and American crews after the Cold War.

Background: from Salyut to Mir

The Soviet Union launched the world’s first space station, Salyut 1, in 1971, and followed it with a series of single-module Salyut stations. The last of these, Salyut 6 and Salyut 7, had two docking ports, allowing cargo ships to resupply crews and letting stays stretch to many months.

Mir took the idea further. Its core module, the base block, had six docking ports: one at the rear and five at the forward node. Specialised laboratory modules could be launched separately and attached, allowing the station to grow over time. Mir means both “peace” and “world” in Russian.

Building the station

The base block was launched on a Proton rocket from Baikonur. The first crew, Leonid Kizim and Vladimir Solovyov, arrived on 15 March 1986 aboard Soyuz T-15. During their mission they flew from Mir to the old Salyut 7 station and back, the only time a crew has travelled between two space stations.

Further modules followed:

• Kvant-1 (1987): astrophysics instruments and gyroscopes for attitude control.
• Kvant-2 (1989): an airlock for spacewalks and extra life-support systems.
• Kristall (1990): materials-processing furnaces and a docking port later used by US shuttles.
• Spektr (1995): Earth-observation equipment and American research hardware.
• Docking Module (1995): delivered by Space Shuttle Atlantis to make shuttle dockings easier.
• Priroda (1996): remote-sensing instruments for studying Earth.

Complete, Mir weighed well over 100 tonnes, and crews arrived on Soyuz spacecraft while uncrewed Progress freighters brought fuel, food and equipment.

Life aboard Mir

Most crews consisted of two or three cosmonauts on expeditions lasting about six months, with handovers overlapping for a few days when a new Soyuz arrived. The station ran on Moscow time, and each crew member was expected to exercise for around two hours a day on a treadmill and an exercise bicycle, held down by elastic cords, to slow the loss of muscle and bone in weightlessness.

Oxygen was produced mainly by Elektron units, which split water by electrolysis, with solid-fuel oxygen canisters as a back-up. Water was recovered from moisture in the cabin air, reducing the amount that had to be brought up by cargo ships. Experiments ranged from growing wheat and other plants in a small greenhouse to producing crystals and studying the Earth’s surface and atmosphere.

Cosmonauts also spent much of their time on maintenance. Dozens of spacewalks were made to install equipment, repair solar panels and inspect the hull. As the station aged beyond its planned lifetime, crews reported cluttered modules, failing equipment and patches of mould, and keeping Mir working became a large part of each expedition.

Records in orbit

Mir was continuously occupied from September 1989 to August 1999, nearly ten years, a record that stood until the International Space Station overtook it in 2010. Its crews carried out thousands of experiments in medicine, biology, materials science and astronomy.

The physician Valeri Polyakov stayed aboard from January 1994 to March 1995, about 437 days, still the longest single spaceflight by any human. He studied how the body adapts to weightlessness, to prepare for possible journeys to Mars.

Sergei Krikalev was aboard from May 1991 to March 1992. While he was in orbit the Soviet Union ceased to exist, and he returned as a citizen of Russia, a story that made him known as the “last Soviet citizen”. The station passed to the new Russian space agency, which struggled with shrinking budgets through the 1990s.

International visitors

Mir hosted visitors from many countries, often on short “guest” flights paid for by their governments or companies. They included cosmonauts from Syria, Bulgaria, Afghanistan, France, Austria and Germany, the Japanese journalist Toyohiro Akiyama in 1990 and Helen Sharman, the first Briton in space, in 1991. In total, more than 100 people from about a dozen countries worked aboard the station.

Shuttle-Mir

After the Cold War, the United States and Russia agreed to cooperate in space. In the Shuttle-Mir programme, also called Phase One of the International Space Station, NASA astronauts lived aboard Mir and American shuttles docked with it.

Norman Thagard became the first American aboard Mir in March 1995. In June 1995 Atlantis made the first of nine shuttle dockings, on mission STS-71, creating the largest spacecraft then assembled in orbit. Seven NASA astronauts made long stays; Shannon Lucid spent 188 days in space in 1996, then a record for an American and for any woman. The programme taught both sides how to work together, lessons applied directly to the International Space Station.

The crises of 1997

On 23 February 1997, with six people aboard, a solid-fuel oxygen-generating canister in the Kvant-1 module caught fire. Flames and thick smoke filled part of the station, and the crew used extinguishers and wore masks. Accounts of how long the fire lasted differ, but it was put out and no one was seriously injured.

On 25 June 1997 commander Vasily Tsibliyev was testing a manual docking system when the uncrewed Progress M-34 cargo ship struck the Spektr module and a solar array. Air began leaking from a puncture. Tsibliyev, flight engineer Aleksandr Lazutkin and NASA astronaut Michael Foale cut cables running through the hatch and sealed Spektr off, saving the station. Mir lost much of its power and spent weeks recovering, and Spektr was never used again.

These incidents, together with computer failures and an ageing structure, fuelled a debate in the United States about whether it was safe to keep sending astronauts. NASA continued the programme, and the last shuttle docking took place in June 1998.

The end of Mir

Russia’s commitment to the International Space Station left little money for Mir. A private venture, MirCorp, funded a final crew, Sergei Zalyotin and Aleksandr Kaleri, who stayed from April to June 2000. Efforts to find further private funding failed.

On 23 March 2001 a Progress ship docked to Mir fired its engines to lower the station’s orbit. Mir broke up during re-entry, and surviving fragments fell into the South Pacific Ocean far from shipping lanes. It had spent about 15 years in orbit, far longer than its planned lifetime of around five years.

Timeline

• 1986, 20 February: The Mir core module is launched from Baikonur.
• 1986, 15 March: The first crew, Kizim and Solovyov, arrives.
• 1987, March-April: Kvant-1 is launched and docked.
• 1989, September: Continuous occupation begins.
• 1995, 22 March: Valeri Polyakov lands after about 437 days in space.
• 1995, 29 June: Atlantis docks with Mir on STS-71.
• 1997, 23 February: A fire breaks out aboard the station.
• 1997, 25 June: Progress M-34 collides with the Spektr module.
• 2000, June: The final crew leaves Mir.
• 2001, 23 March: Mir is deorbited over the South Pacific.

Why it matters

Mir proved that humans could live and work in space for more than a year and showed how a station could be built and repaired piece by piece. As the place where Russian and American crews first lived together, it bridged the Cold War space race and the international cooperation of the ISS.