Expeditions Mir was visited by a total of 28 long-duration or "principal" crews, each of which was given a sequential expedition number formatted as EO-X. Expeditions varied in length (from the 72-day flight of the crew of
EO-28 to the 437-day flight of
Valeri Polyakov), but generally lasted around six months. The station was occupied for a total of four distinct periods; 12 March–16 July 1986 (
EO-1), 5 February 1987 – 27 April 1989 (EO-2–EO-4), the record-breaking run from 5 September 1989 – 28 August 1999 (EO-5–EO-27), and 4 April–16 June 2000 (
EO-28).
Leonid Kizim and
Vladimir Solovyov first docked with
Mir on 15 March 1986. During their nearly 51-day stay on
Mir, they brought the station online and checked its systems. They unloaded two
Progress spacecraft launched after their arrival,
Progress 25 and
Progress 26. On 5 May 1986, they undocked from
Mir for a day-long journey to Salyut 7. They spent 51 days there and gathered 400 kg of scientific material from Salyut 7 for return to
Mir. While Soyuz T-15 was at Salyut 7, the uncrewed
Soyuz TM-1 arrived at the unoccupied
Mir and remained for 9 days, testing the new
Soyuz TM model. Soyuz T-15 redocked with
Mir on 26 June and delivered the experiments and 20 instruments, including a multichannel
spectrometer. The EO-1 crew spent their last 20 days on
Mir conducting Earth observations before returning to Earth on 16 July 1986, leaving the new station unoccupied. The Soyuz TM-2 launch was the beginning of a string of 6 Soyuz launches and three long-duration crews between 5 February 1987 and 27 April 1989. This period also saw the first international visitors,
Muhammed Faris (Syria),
Abdul Ahad Mohmand (Afghanistan) and
Jean-Loup Chrétien (France). With the departure of
EO-4 on
Soyuz TM-7 on 27 April 1989 the station was again left unoccupied.
Soyuz TM-9 launched
EO-6 crew members
Anatoly Solovyev and
Aleksandr Balandin on 11 February 1990. While docking, the EO-5 crew noted that three thermal blankets on the ferry were loose, potentially creating problems on reentry, but it was decided that they would be manageable. Their stay on board
Mir saw the addition of the
Kristall module, launched 31 May 1990. The first docking attempt on 6 June was aborted due to an attitude control thruster failure.
Kristall arrived at the front port on 10 June and was relocated to the lateral port opposite
Kvant-2 the next day, restoring the equilibrium of the complex. Due to the delay in the docking of
Kristall, EO-6 was extended by 10 days to permit the activation of the module's systems and to accommodate an EVA to repair the loose thermal blankets on Soyuz TM-9. The
EO-7 relief crew arrived aboard
Soyuz TM-10 on 3 August 1990. The new crew arrived at
Mir with
quail for
Kvant-2's cages, one of which laid an egg en route to the station. It was returned to Earth, along with 130 kg of experiment results and industrial products, in Soyuz TM-9. The launch of
Soyuz TM-19, carrying the
EO-16 crew, was delayed due to the unavailability of a payload fairing for the booster that was to carry it, but the spacecraft eventually left Earth on 1 July 1994 and docked two days later. They stayed only four months to allow the Soyuz schedule to line up with the planned Space Shuttle manifest, and so Polyakov greeted a second resident crew in October, prior to the undocking of Soyuz TM-19, when the
EO-17 crew arrived in
Soyuz TM-20. Five weeks after
Discovery departure, the
EO-18 crew, including the first US cosmonaut
Norman Thagard, arrived in
Soyuz TM-21. The EO-17 crew left a few days later, with Polyakov completing his record-breaking 437-day spaceflight. During EO-18, the
Spektr science module (which served as living and working space for American astronauts) was launched aboard a
Proton rocket and docked to the station, carrying research equipment from America and other nations. The expedition's crew returned to Earth aboard following the first Shuttle–
Mir docking mission,
STS-71.
Atlantis, launched on 27 June 1995, successfully docked with
Mir on 29 June becoming the first US spacecraft to dock with a Russian spacecraft since the
ASTP in 1975. The orbiter delivered the
EO-19 crew and returned the EO-18 crew to Earth. The
EO-20 crew were launched on 3 September, followed in November by the arrival of the docking module during
STS-74. On 21 February 1996, the two-man
EO-21 crew was launched aboard
Soyuz TM-23, and they were soon joined by US crew member
Shannon Lucid, who was brought to the station by
Atlantis during
STS-76. During this mission, the first joint US spacewalk on
Mir took place, deploying the
Mir Environmental Effects Payload package for the docking module. Lucid became the first American to carry out a long-duration mission aboard
Mir with her 188-day mission, which set the US single spaceflight record. During Lucid's time aboard
Mir,
Priroda, the station's final module, arrived as did French visitor
Claudie Haigneré flying the
Cassiopée mission. The flight aboard
Soyuz TM-24 also delivered the
EO-22 crew of
Valery Korzun and
Aleksandr Kaleri. On 16 September 1996, with the launch of
Atlantis and the
STS-79 flight, Lucid's stay aboard
Mir ended. During this fourth docking,
John Blaha transferred onto
Mir to take his place as resident US astronaut. His stay on the station improved operations in a number of areas, including transfer procedures for a docked space shuttle, "hand-over" procedures for long-duration American crew members, and "ham"
amateur radio communications, as well as two spacewalks to reconfigure the station's power grid. Blaha spent four months with the EO-22 crew before returning to Earth aboard
Atlantis on
STS-81 in January 1997, at which point he was replaced by physician
Jerry Linenger. During his flight, Linenger became the first American to conduct a spacewalk from a foreign space station and the first to test the Russian-built
Orlan-M spacesuit alongside Russian cosmonaut
Vasili Tsibliyev, flying
EO-23. All three crew members of EO-23 performed a "fly-around" in
Soyuz TM-25 spacecraft. After these incidents, the US Congress and NASA considered whether to abandon the programme out of concern for the astronauts' safety, but NASA administrator
Daniel Goldin decided to continue. Wolf spent 119 days aboard
Mir with the EO-24 crew and was replaced during
STS-89 with
Andy Thomas, who carried out the last US expedition on
Mir. The
EO-25 crew arrived in
Soyuz TM-27 in January 1998 before Thomas returned to Earth on the final Shuttle–
Mir mission,
STS-91.
Final days and deorbit on 23 March 2001. Following the 8 June 1998 departure of
Discovery, the EO-25 crew of
Budarin and
Musabayev remained on
Mir, completing materials experiments and compiling a station inventory. On 2 July,
Roskosmos director Yuri Koptev announced that, due to a lack of funding to keep
Mir active, the station would be deorbited in June 1999.
Mirs deorbit was carried out in three stages. The first stage involved waiting for
atmospheric drag to
reduce the station's orbit to an average of . This began with the docking of
Progress M1-5, a modified version of the
Progress-M carrying 2.5 times more fuel in place of supplies. The second stage was the transfer of the station into a orbit. This was achieved with two burns of Progress M1-5's control engines at 00:32 UTC and 02:01 UTC on 23 March 2001. After a two-orbit pause, the third and final stage of the deorbit began with the burn of Progress M1-5's control engines and main engine at 05:08 UTC, lasting 22+ minutes.
Atmospheric reentry (arbitrarily defined beginning at AMSL) occurred at 05:44 UTC near
Nadi, Fiji. Major destruction of the station began around 05:52 UTC and most of the unburned fragments fell into the
South Pacific Ocean around 06:00 UTC.
Visiting spacecraft docked with
Mir as seen from the during
STS-79 Mir was primarily supported by the Russian
Soyuz and
Progress spacecraft and had two ports available for docking them. Initially, the fore and aft ports of the core module could be used for dockings, but following the permanent berthing of
Kvant-1 to the aft port in 1987, the rear port of the new module took on this role from the core module's aft port. Each port was equipped with the plumbing required for Progress cargo ferries to replace the station's fluids and also the guidance systems needed to guide the spacecraft for docking. Two such systems were used on
Mir; the rear ports of both the core module and
Kvant-1 were equipped with both the
Igla and
Kurs systems, whilst the core module's forward port featured only the newer Kurs. Two models of Soyuz flew to
Mir;
Soyuz T-15 was the only Igla-equipped
Soyuz-T to visit the station, whilst all other flights used the newer, Kurs-equipped
Soyuz-TM. A total of 31 (30 crewed,
1 uncrewed) Soyuz spacecraft flew to the station over a 14-year period. As a result, when its cargo had been unloaded, each Progress was refilled with rubbish, spent equipment and other waste which was destroyed, along with the Progress itself, on reentry. The shuttles provided crew rotation of the American astronauts on station and carried cargo to and from the station, performing some of the largest transfers of cargo of the time. With a space shuttle docked to
Mir, the temporary enlargements of living and working areas amounted to a complex that was the largest
spacecraft in history at that time, with a combined mass of . The facility is now used to control the
Russian Orbital Segment of the ISS. and the third was sold to an educational and entertainment complex in the US in 1997.
Tommy Bartlett Exploratory purchased the unit and had it shipped to
Wisconsin Dells, Wisconsin, where it became the centrepiece of the complex's Space Exploration wing.
Safety aspects Ageing systems and atmosphere In the later years of the programme, particularly during the Shuttle-
Mir programme,
Mir suffered from various systems failures. It had been designed for five years of use, but eventually flew for fifteen, and in the 1990s was showing its age, with frequent computer crashes, loss of power, uncontrolled tumbles through space and leaking pipes.
Jerry Linenger in his book about his time on the facility says that the cooling system had developed tiny leaks too small and numerous to be repaired, that permitted the constant release of
coolant. He says that it was especially noticeable after he had made a spacewalk and become used to the bottled air in his spacesuit. When he returned to the station and again began breathing the air inside
Mir, he was shocked by the intensity of the smell and worried about the possible negative health effects of breathing such contaminated air. coolant released by
RORSAT nuclear powered satellites,
small needles, and many other objects. These objects, in addition to natural
micrometeoroids, posed a threat to the station as they could puncture pressurised modules and cause damage to other parts of the station, such as the solar arrays. Micrometeoroids also posed a risk to
spacewalking cosmonauts, as such objects could
puncture their spacesuits, causing them to depressurise. Meteor showers in particular posed a risk, and, during such storms, the crews slept in their Soyuz ferries to facilitate an emergency evacuation should
Mir be damaged. ==See also==