View source for Astronomy:Mir

{{Short description|Soviet/Russian space station that operated in low Earth orbit from 1986 to 2001}}
{{Italic title}}
{{Infobox space station
|station              = ''Mir''
|image        = Mir Space Station viewed from Endeavour during STS-89.jpg
|image_caption= ''Mir''  seen from {{OV|105}} during [[Engineering:STS-89|STS-89]] (28 January 1998)
|insignia             = Mir insignia.svg
|insignia_size        =
|insignia_caption     = ''Mir'' insignia
|sign                 = ''Mir''
|crew                 = 3
|launch               = 20 February 1986 – 23 April 1996
|launch_pad           = LC-200/39, and LC-81/23, Baikonur Cosmodrome<br>[[Astronomy:Kennedy Space Center Launch Complex 39A|Launch Complex 39A]],<br>Kennedy Space Center
|reentry              = 23 March 2001<br>05:59 [[UTC]]
|mass                 = 129,700 kg<br>(285,940 [[Pound (mass)|lb]])
|length               = 19&nbsp;m (62.3&nbsp;ft)<br><small>from core module to ''Kvant''-1</small>
|width                = 31&nbsp;m (101.7&nbsp;ft)<br><small>from ''Priroda'' to docking module</small>
|height               = 27.5&nbsp;m (90.2&nbsp;ft)<br><small>from ''Kvant''-2 to ''Spektr''</small>
|volume               = {{val|350|u=m3}}
|pressure             = c. 101.3&nbsp;[[Pascal (unit)|kPa]] (29.91&nbsp;[[Inch of mercury|inHg]], 1 [[Physics:Atmosphere (unit)|atm]])
|perigee              = 354&nbsp;km (189&nbsp;[[Nautical mile|nmi]]) AMSL <small><math>\bar{x} \!\,</math></small>
|apogee               = 374&nbsp;km (216&nbsp;nmi) AMSL <small><math>\bar{x} \!\,</math></small>
|inclination          = 51.6 [[Degree (angle)|degrees]]
|speed                = 7.7&nbsp;km/s<br />(27,700&nbsp;km/h, 17,200&nbsp;mph)
|period               = 91.9 minutes <small><math>\bar{x} \!\,</math></small>
|orbits_day           = 15.7 <small><math>\bar{x} \!\,</math></small>
|in_orbit             = {{age in days|20 February 1986|23 March 2001}} ({{age in years and days|20 February 1986|23 March 2001|sep=and}})
|occupied             = 4,592
|orbits               = 86,331
|NSSDC_ID             = 1986-017A
|as_of                = 23 March 2001<br>(unless noted otherwise)
|stats_ref            = <ref>{{cite web |url=http://www.heavens-above.com/orbit.aspx?lat=48.213&lng=16.296&alt=302&loc=Kuffner-Sternwarte&TZ=CET&satid=16609 |access-date=30 June 2009 |publisher=Heavens-Above.com |date=23 March 2001|title=Mir-Orbit Data |archive-date=8 June 2011 |archive-url=https://web.archive.org/web/20110608215552/http://www.heavens-above.com/orbit.aspx?lat=48.213&lng=16.296&alt=302&loc=Kuffner-Sternwarte&TZ=CET&satid=16609 |url-status=live}}</ref><ref>{{cite web|url=http://www.esa.int/esaCP/ESA28WTM5JC_Life_2.html|title=Mir FAQ – Facts and history|publisher=[[Organization:European Space Agency|European Space Agency]]|access-date=19 August 2010|date=21 February 2001|archive-date=22 October 2012|archive-url=https://web.archive.org/web/20121022004442/http://www.esa.int/esaCP/ESA28WTM5JC_Life_2.html |url-status=live}}</ref><ref>{{cite web|url=http://spaceflightnow.com/mir/status.html|publisher=Spaceflight Now|title=Mir Space Station – Mission Status Center|date=23 March 2001|access-date=19 August 2010|archive-date=17 June 2009|archive-url=https://web.archive.org/web/20090617231902/http://spaceflightnow.com/mir/status.html |url-status=live}}</ref><ref>{{cite web|date=23 July 2010|access-date=22 August 2010|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1986-017A |publisher=NASA|title=NASA – NSSDC – Spacecraft – Details – Mir|df=dmy-all|archive-date=19 June 2018|archive-url=https://web.archive.org/web/20180619210408/https://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=1986-017A |url-status=live}}</ref><ref>{{cite web|access-date=22 August 2010|title=Soviet/Russian space programmes Q&A |publisher= NASASpaceflight.com |url=http://forum.nasaspaceflight.com/index.php?topic=5966.465|archive-date=16 May 2019|archive-url=https://web.archive.org/web/20190516061114/https://forum.nasaspaceflight.com/index.php?topic=5966.465 |url-status=live}}</ref><ref name="MirBIS"/><ref name="FinalBIS"/><ref name="OrbitCalc"/><ref name="MirObs">{{cite web|title=Mir Space Station Observing|url=http://www.satobs.org/mir.html|publisher=Satobs.org|access-date=12 September 2010|date=28 March 2001|archive-date=23 September 2018|archive-url=https://web.archive.org/web/20180923021140/http://www.satobs.org/mir.html |url-status=live}}</ref><ref>{{cite web|title=Baikonur LC200/39|url=http://www.astronautix.com/sites/bai20039.htm |publisher=Encyclopedia Astronautica |access-date=25 September 2010|author=Mark Wade|date=4 September 2010|url-status=dead|archive-url=https://web.archive.org/web/20100824131238/http://www.astronautix.com/sites/bai20039.htm |archive-date=24 August 2010}}{{unreliable source inline|date=February 2021}}</ref>{{unreliable source inline|date=February 2021}}<ref>{{cite web|title=Baikonur LC81/23 |url= http://www.astronautix.com/sites/baic8123.htm |publisher=Encyclopedia Astronautica|access-date=25 September 2010|author=Mark Wade|date=4 September 2010|url-status=dead|archive-url= https://web.archive.org/web/20100201083155/http://astronautix.com/sites/baic8123.htm |archive-date=1 February 2010}}{{unreliable source inline|date=February 2021}}</ref>{{unreliable source inline|date=February 2021}}<ref>{{cite report|title=Cabin Air Quality On Board Mir and the International Space Station—A Comparison|date=22 January 2007|url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20070013700_2007011164.pdf |last1=Macatangay|first1= A.V.|last2=Perry|first2= J.L.|name-list-style=amp|page=2|publisher=NASA|location=Johnson Space Center & Marshall Spaceflight Center|access-date=|archive-date=21 September 2013|archive-url=https://web.archive.org/web/20130921061157/http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20070013700_2007011164.pdf |url-status=dead}}</ref>
|configuration_image  = Mir diagram.svg
|configuration_size   =
|configuration_caption= Station elements as of May 1996
|configuration_alt    = The main components of Mir shown as a line diagram, with each module highlighted in a different colour
}}
{{Soviet space program sidebar}}

'''''Mir''''' ({{lang-ru|Мир}}, {{IPA-ru|ˈmʲir|IPA}}; {{literal translation|peace|world}}) was a space station that operated in [[Astronomy:Low Earth orbit|low Earth orbit]] from 1986 to 2001, operated by the [[Place:Soviet Union|Soviet Union]] and later by {{wipe|Russia}}. ''Mir'' was the first modular space station and was assembled in orbit from 1986&nbsp;to&nbsp;1996. It had a greater mass than any previous [[Engineering:Spacecraft|spacecraft]]. At the time it was the largest artificial satellite in orbit, succeeded by the [[Astronomy:International Space Station|International Space Station]] (ISS) after ''Mir''<nowiki>'</nowiki>s [[Astronomy:Orbital decay|orbit decayed]]. The station served as a microgravity [[Research|research]] laboratory in which crews conducted [[Experiment|experiment]]s in [[Biology:Biology|biology]], human biology, [[Physics:Physics|physics]], [[Astronomy:Astronomy|astronomy]], [[Physics:Meteorology|meteorology]], and spacecraft systems with a goal of developing technologies required for permanent occupation of [[Astronomy:Outer space|space]].

''Mir'' was the first continuously inhabited long-term research station in orbit and held the record for the longest continuous [[Astronomy:Human presence in space|human presence in space]] at 3,644 days, until it was surpassed by the ISS on 23 October 2010.<ref name="Mirrecord">{{cite news|last=Jackman|first=Frank|title=ISS Passing Old Russian Mir In Crewed Time|url=http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=space&id=news/asd/2010/10/28/11.xml|newspaper=Aviation Week|date=29 October 2010}}{{Dead link|date=August 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> It holds the record for the longest single human spaceflight, with [[Biography:Valeri Polyakov|Valeri Polyakov]] spending 437 days and 18 hours on the station between 1994 and 1995. ''Mir'' was occupied for a total of twelve and a half years out of its fifteen-year lifespan, having the capacity to support a resident crew of three, or larger crews for short visits.

Following the success of the [[Engineering:Salyut programme|Salyut programme]], ''Mir'' represented the next stage in the Soviet Union's space station programme. The first module of the station, known as the [[Astronomy:Mir Core Module|core module]] or base block, was launched in 1986 and followed by six further modules. Proton [[Engineering:Rocket|rocket]]s were used to launch all of its components except for the [[Astronomy:Mir Docking Module|docking module]], which was installed by US [[Engineering:Space Shuttle|Space Shuttle]] mission [[Engineering:STS-74|STS-74]] in 1995. When complete, the station consisted of seven pressurised modules and several unpressurised components. Power was provided by several [[Physics:Photovoltaic system#Photovoltaic arrays|photovoltaic arrays]] attached directly to the modules. The station was [[Astronomy:Orbital station-keeping|maintained at an orbit]] between {{convert|296|km|mi|0|abbr=on}} and {{convert|421|km|mi|0|abbr=on}} altitude and travelled at an average speed of 27,700&nbsp;km/h (17,200&nbsp;mph), completing 15.7 orbits per day.<ref name="MirBIS">{{cite book|title=The History of Mir 1986–2000|year=2000|publisher=British Interplanetary Society|isbn=978-0-9506597-4-9|editor=Hall, R.|url-access=registration|url=https://archive.org/details/historyofmir19860000unse}}{{page number|date=February 2021}}</ref>{{page number|date=February 2021}}<ref name="FinalBIS">{{cite book|title=Mir: The Final Year|year=2001|publisher=British Interplanetary Society|isbn=978-0-9506597-5-6|editor=Hall, R.}}{{page number|date=February 2021}}</ref>{{page number|date=February 2021}}<ref name="OrbitCalc">{{cite web|title=Orbital period of a planet|url=http://www.calctool.org/CALC/phys/astronomy/planet_orbit|publisher=CalcTool|access-date=12 September 2010|archive-date=12 November 2019|archive-url=https://web.archive.org/web/20191112095042/http://www.calctool.org/CALC/phys/astronomy/planet_orbit|url-status=live}}</ref>

The station was launched as part of the Soviet Union's [[Astronomy:Soviet space program|crewed spaceflight programme]] effort to maintain a long-term research outpost in space, and following the collapse of the USSR, was operated by the new Russian Federal Space Agency (RKA). As a result, most of the station's occupants were Soviet; through international collaborations such as the [[Astronomy:Interkosmos|Interkosmos]], [[Astronomy:Euromir|Euromir]] and [[Astronomy:Shuttle–Mir program|Shuttle–''Mir'']] programmes, the station was made accessible to space travellers from several Asian, European and North American nations. ''Mir'' [[Astronomy:Deorbit of Mir|was deorbited]] in March 2001 after funding was cut off. The cost of the ''Mir'' programme was estimated by former RKA General Director Yuri Koptev in 2001 as $4.2&nbsp;billion over its lifetime (including development, assembly and orbital operation).<ref>{{cite news|title=Russians Find Pride, and Regret, in Mir's Splashdown|url=https://www.nytimes.com/2001/03/24/science/24MIR.html|newspaper=New York Times|access-date=9 March 2011|author=Patrick E. Tyler|date=24 March 2001|archive-date=28 April 2014|archive-url=https://web.archive.org/web/20140428045543/http://www.nytimes.com/2001/03/24/science/24MIR.html|url-status=live}}</ref>

==Origins==
''Mir'' was authorised by a 17 February 1976 decree, to design an improved model of the Salyut DOS-17K space stations. Four Salyut space stations had been launched since 1971, with three more being launched during ''Mir'''s development. It was planned that the station's core module ([[Astronomy:Mir Core Module|DOS-7]] and the backup DOS-8) would be equipped with a total of four docking ports; two at either end of the station as with the Salyut stations, and an additional two ports on either side of a docking sphere at the front of the station to enable further modules to expand the station's capabilities. By August 1978, this had evolved to the final configuration of one aft port and five ports in a spherical compartment at the forward end of the station.<ref name="Encyclopedia Astronautica"/>{{failed verification|date=February 2021}}{{unreliable source inline|date=February 2021}}

It was originally planned that the ports would connect to {{convert|7.5|t|ST|adj=on}} modules derived from the Soyuz spacecraft. These modules would have used a Soyuz propulsion module, as in Soyuz and Progress, and the descent and orbital modules would have been replaced with a long laboratory module.<ref name="Encyclopedia Astronautica"/> Following a February 1979 governmental resolution, the programme was consolidated with Vladimir Chelomei's crewed [[Astronomy:Almaz|Almaz]] military space station programme. The docking ports were reinforced to accommodate {{convert|20|t|ST|adj=on}} space station modules based on the TKS spacecraft. NPO Energia was responsible for the overall space station, with work subcontracted to [[Company:Khrunichev State Research and Production Space Center|KB Salyut]], due to ongoing work on the Energia [[Engineering:Launch vehicle|rocket]] and [[Engineering:Salyut 7|Salyut 7]], Soyuz-T, and Progress spacecraft. KB Salyut began work in 1979, and drawings were released in 1982 and 1983. New systems incorporated into the station included the Salyut 5B digital flight control computer and gyrodyne flywheels (taken from Almaz), Kurs automatic rendezvous system, [[Engineering:Luch (satellite)|''Luch'' satellite]] communications system, Elektron oxygen generators, and [[Engineering:ISS ECLSS#Vozdukh|Vozdukh]] [[Chemistry:Rebreather#Carbon dioxide scrubber|carbon dioxide scrubbers]].<ref name="Encyclopedia Astronautica"/>{{failed verification|date=February 2021}}{{unreliable source inline|date=February 2021}}

By early 1984, work on ''Mir'' had halted while all resources were being put into the [[Engineering:Buran programme|Buran programme]] in order to prepare the [[Engineering:Buran (spacecraft)|''Buran'' spacecraft]] for flight testing. Funding resumed in early 1984 when [[Biography:Valentin Glushko|Valentin Glushko]] was ordered by the Central Committee's Secretary for Space and Defence to orbit ''Mir'' by early 1986, in time for the 27th Communist Party Congress.<ref name="Encyclopedia Astronautica"/>{{failed verification|date=February 2021}}{{unreliable source inline|date=February 2021}}

It was clear that the planned processing flow could not be followed and still meet the 1986 launch date. It was decided on [[Astronomy:Cosmonautics Day|Cosmonaut's Day]] (12 April) 1985 to ship the flight model of the [[Astronomy:Mir Core Module|base block]] to the Baikonur Cosmodrome and conduct the systems testing and integration there. The module arrived at the launch site on 6 May, with 1100 of 2500 cables requiring rework based on the results of tests to the ground test model at Khrunichev. In October, the base block was rolled outside its [[Engineering:Cleanroom|cleanroom]] to carry out communications tests. The first launch attempt on 16 February 1986 was scrubbed when the spacecraft communications failed, but the second launch attempt, on 19 February 1986 at 21:28:23 UTC, was successful, meeting the political deadline.<ref name="Encyclopedia Astronautica"/>{{failed verification|date=February 2021}}{{unreliable source inline|date=February 2021}}

==Station structure==

===Assembly===
[[File:Mir Docking Cone Placement and Module Movements.pdf|right|thumb|upright|A diagram showing the ''Konus'' drogue and module movements around ''Mir'''s docking node<ref name="SSA">{{cite book|title=Space Shuttle Almanac|isbn=978-0-9696313-0-9|orig-year=1992|year=2011|author1=Joel W. Powell|author2=Lee Brandon-Cremer|name-list-style=amp|url=http://www.spaceshuttlealmanac.com/|access-date=23 August 2011|archive-date=2 October 2011|archive-url=https://web.archive.org/web/20111002020622/http://www.spaceshuttlealmanac.com/|url-status=live}}</ref>]]
The orbital assembly of ''Mir'' began on 19 February 1986 with the launch of the ''[[Engineering:Proton-K|Proton-K]]'' rocket. Four of the six modules which were later added ([[Astronomy:Kvant-2|''Kvant''-2]] in 1989, ''[[Astronomy:Kristall|Kristall]]'' in 1990, ''[[Astronomy:Spektr|Spektr]]'' in 1995 and ''[[Astronomy:Priroda|Priroda]]'' in 1996) followed the same sequence to be added to the main ''Mir'' complex. Firstly, the module would be launched independently on its own Proton-K and chase the station automatically. It would then dock to the forward docking port on the core module's docking node, then extend its [[Astronomy:Lyappa arm|Lyappa arm]] to mate with a fixture on the node's exterior. The arm would then lift the module away from the forward docking port and rotate it on to the radial port where it was to mate, before lowering it to dock. The node was equipped with only two ''Konus'' drogues, which were required for dockings. This meant that, prior to the arrival of each new module, the node would have to be depressurised to allow spacewalking cosmonauts to manually relocate the drogue to the next port to be occupied.<ref name="MirBIS"/>{{page number|date=February 2021}}<ref name="SSSM"/>{{page number|date=February 2021}}

The other two expansion modules, [[Astronomy:Kvant-1|''Kvant''-1]] in 1987 and the [[Astronomy:Mir Docking Module|docking module]] in 1995, followed different procedures. ''Kvant''-1, having, unlike the four modules mentioned above, no engines of its own, was launched attached to a tug based on the TKS spacecraft which delivered the module to the aft end of the core module instead of the docking node. Once hard docking had been achieved, the tug undocked and deorbited itself. The docking module, meanwhile, was launched aboard {{OV|104}} during [[Engineering:STS-74|STS-74]] and mated to the orbiter's Orbiter Docking System. ''Atlantis'' then docked, via the module, to ''Kristall'', then left the module behind when it undocked later in the mission.<ref name="SSSM"/>{{rp|248–249}}<ref name="STS-74"/> Various other external components, including three truss structures, several experiments and other unpressurised elements were also mounted to the exterior of the station by cosmonauts conducting a total of eighty spacewalks over the course of the station's history.<ref name="SSSM"/>{{page number|date=February 2021}}

The station's assembly marked the beginning of the third generation of space station design, being the first to consist of more than one primary spacecraft (thus opening a new era in [[Engineering:Space architecture|space architecture]]). First generation stations such as [[Engineering:Salyut 1|Salyut 1]] and [[Engineering:Skylab|Skylab]] had monolithic designs, consisting of one module with no resupply capability; the second generation stations [[Engineering:Salyut 6|Salyut 6]] and [[Engineering:Salyut 7|Salyut 7]] comprised a monolithic station with two ports to allow consumables to be replenished by cargo spacecraft such as [[Engineering:Progress (spacecraft)|Progress]]. The capability of ''Mir'' to be expanded with add-on modules meant that each could be designed with a specific purpose in mind (for instance, the core module functioned largely as living quarters), thus eliminating the need to install all the station's equipment in one module.<ref name="SSSM"/>{{page number|date=February 2021}}

===Pressurised modules===
In its completed configuration, the space station consisted of seven different modules, each launched into orbit separately over a period of ten years by either [[Engineering:Proton-K|Proton-K]] rockets or {{OV|104}}.
{{Clear}}
{| class="wikitable" style="width:auto; margin:auto;"
|- style="background:#EFEFEF;" class="is-sticky"
! Module
! Expedition
! Launch date
! Launch system
! style="width:100px;"| Nation
! style="width:82px;"| Isolated view
! style="width:82px;"| Station view
|-
| rowspan="2" | ''[[Astronomy:Mir Core Module|Mir Core Module]]''<br /><small>(Core Module)</small>
| N/A
| 19 February 1986
| [[Engineering:Proton-K|Proton-K]]
| Soviet Union
| rowspan="2" | [[File:RP1357 p103 Mir base block.svg|80px]]
| rowspan="2" | [[File:Mir Core Module.JPG|center|40px]]
|- style="border-bottom: 3px solid gray"
| colspan="4" | The base block for the entire ''Mir'' complex, the core module, or DOS-7, provided the main living quarters for resident crews and contained environmental systems, early attitude<!--It's supposed to be ATTitude, meaning orientation - please don't change this to aLTitude.--> control systems and the station's main engines. The module was based on hardware developed as part of the Salyut programme, and consisted of a stepped-cylinder main compartment and a spherical 'node' module, which served as an airlock and provided ports to which four of the station's expansion modules were berthed and to which a Soyuz or Progress spacecraft could dock. The module's aft port served as the berthing location for [[Astronomy:Kvant-1|''Kvant''-1]].<ref name="MHH">{{cite book|url=http://en.wikisource.org/wiki/Mir_Hardware_Heritage|title=Mir Hardware Heritage|author=David S. F. Portree|publisher=NASA|date=March 1995|access-date=8 July 2009|archive-date=15 July 2009|archive-url=https://web.archive.org/web/20090715235246/http://en.wikisource.org/wiki/Mir_Hardware_Heritage|url-status=live}}{{page number|date=February 2021}}</ref>{{page number|date=February 2021}}
|-
| rowspan="2" | [[Astronomy:Kvant-1|''Kvant''-1]]<br /><small>(Astrophysics Module)</small>
| [[Astronomy:Mir EO-2|EO-2]]
| 31 March 1987
| [[Engineering:Proton-K|Proton-K]]
| Soviet Union
| rowspan="2" | [[File:RP1357 p162 Kvant module.svg|80px]]
| rowspan="2" | [[File:Mir-kvant.jpg|80px]]
|- style="border-bottom: 3px solid gray"
| colspan="4" | The first expansion module to be launched, ''Kvant''-1 consisted of two pressurised working compartments and one unpressurised experiment compartment. Scientific equipment included an [[Astronomy:X-ray telescope|X-ray telescope]], an [[Astronomy:Ultraviolet astronomy|ultraviolet telescope]], a wide-angle camera, high-energy X-ray experiments, an X-ray/gamma ray detector, and the Svetlana electrophoresis unit. The module also carried six [[Engineering:Gyroscope|gyrodynes]] for attitude<!--It's supposed to be ATTitude, meaning orientation - please don't change this to aLTitude.--> control, in addition to life support systems including an Elektron oxygen generator and a [[Engineering:ISS ECLSS#Vozdukh|Vozdukh]] carbon dioxide scrubber.<ref name="MHH"/>{{page number|date=February 2021}}
|-
| rowspan="2" | [[Astronomy:Kvant-2|''Kvant''-2]]<br /><small>(Augmentation Module)</small>
| [[Astronomy:Mir EO-5|EO-5]]
| 26 November 1989
| [[Engineering:Proton-K|Proton-K]]
| Soviet Union
| rowspan="2" | [[File:RP1357 p164 Kvant 2 module.svg|80px]]
| rowspan="2" | [[File:Mir Kvant 1-Base Block-Kvant 2.jpg|80px]]
|- style="border-bottom: 3px solid gray"
| colspan="4" | The first TKS based module, ''Kvant''-2, was divided into three compartments: an EVA airlock, an instrument/cargo compartment (which could function as a backup airlock), and an instrument/experiment compartment. The module also carried a Soviet version of the [[Astronomy:Manned Maneuvering Unit|Manned Maneuvering Unit]] for the [[Engineering:Orlan space suit|Orlan space suit]], referred to as ''Ikar'', a system for regenerating water from urine, a shower, the ''Rodnik'' water storage system and six gyrodynes to augment those already located in ''Kvant''-1. Scientific equipment included a high-resolution camera, spectrometers, X-ray sensors, the Volna 2 fluid flow experiment, and the Inkubator-2 unit, which was used for hatching and raising [[Biology:Quail|quail]].<ref name="MHH"/>{{page number|date=February 2021}}
|-
| rowspan="2" | ''[[Astronomy:Kristall|Kristall]]''<br /><small>(Technology Module)</small>
| [[Astronomy:Mir EO-6|EO-6]]
| 31 May 1990
| [[Engineering:Proton-K|Proton-K]]
| Soviet Union
| rowspan="2" | [[File:RP1357 p166 Kristall module.svg|80px]]
| rowspan="2" | [[File:Mir from Soyuz TM-17.jpg|80px]]
|- style="border-bottom: 3px solid gray"
| colspan="4" | ''Kristall'', the fourth module, consisted of two main sections. The first was largely used for materials processing (via various processing furnaces), astronomical observations, and a biotechnology experiment utilising the Aniur electrophoresis unit. The second section was a docking compartment which featured two APAS-89 docking ports initially intended for use with the [[Engineering:Buran programme|''Buran'' programme]] and eventually used during the Shuttle-''Mir'' programme. The docking compartment also contained the Priroda 5 camera used for Earth resources experiments. ''Kristall'' also carried six [[Engineering:Control moment gyroscope|control moment gyroscope]]s (CMGs, or "gyrodynes") for attitude<!--It's supposed to be ATTitude, meaning orientation - please don't change this to aLTitude.--> control to augment those already on the station, and two collapsible solar arrays.<ref name="MHH"/>{{page number|date=February 2021}}
|-
| rowspan="2" | ''[[Astronomy:Spektr|Spektr]]''<br /><small>(Power Module)</small>
| EO-18
| 20 May 1995
| [[Engineering:Proton-K|Proton-K]]
| Russia
| rowspan="2" | [[File:Spektr module drawing.png|80px]]
| rowspan="2" | [[File:Mir from STS-74.jpg|80px]]
|- style="border-bottom: 3px solid gray"
| colspan="4" | ''Spektr'' was the first of the three modules launched during the Shuttle-''Mir'' programme; it served as the living quarters for American astronauts and housed [[Organization:NASA|NASA]]-sponsored experiments. The module was designed for remote observation of Earth's environment and contained atmospheric and surface research equipment. It featured four solar arrays which generated approximately half of the station's electrical power. The module also had a science airlock to expose experiments to the vacuum of space selectively. ''Spektr'' was rendered unusable following the collision with [[Engineering:Progress M-34|Progress M-34]] in 1997 which damaged the module, exposing it to the vacuum of space.<ref name="SSSM"/>{{page number|date=February 2021}}
|-
| rowspan="2" | [[Astronomy:Mir Docking Module|Docking Module]]
| [[Astronomy:Mir EO-20|EO-20]]
| 15 November 1995
| {{OV|104}}<br />([[Engineering:STS-74|STS-74]])
| US
| rowspan="2" | [[File:Mir Docking Module drawing.svg|80px]]
| rowspan="2" | [[File:Mir from STS-74PLB.jpg|80px]]
|- style="border-bottom: 3px solid gray"
| colspan="4" | The docking module was designed to help simplify [[Engineering:Space Shuttle|Space Shuttle]] dockings to ''Mir''. Before the first shuttle docking mission ([[Engineering:STS-71|STS-71]]), the ''[[Astronomy:Kristall|Kristall]]'' module had to be tediously moved to ensure sufficient clearance between ''Atlantis'' and ''Mir'''s solar arrays. With the addition of the docking module, enough clearance was provided without the need to relocate ''Kristall''. It had two identical APAS-89 docking ports, one attached to the distal port of ''Kristall'' with the other available for shuttle docking.{{r|SSSM|p=247–249}}
|-
| rowspan="2" | ''[[Astronomy:Priroda|Priroda]]''<br /><small>(Earth Sensing Module)</small>
| [[Astronomy:Mir EO-21|EO-21]]
| 26 April 1996
| [[Engineering:Proton-K|Proton-K]]
| Russia
| rowspan="2" | [[File:Priroda module drawing.svg|80px]]
| rowspan="2" | [[File:Mir from STS-81.jpg|80px]]
|- style="border-bottom: 3px solid gray"
| colspan="4" | The seventh and final ''Mir'' module, ''Priroda'''s primary purpose was to conduct Earth resource experiments through remote sensing and to develop and verify remote sensing methods. The module's experiments were provided by twelve different nations, and covered microwave, visible, near infrared, and infrared spectral regions using both passive and active sounding methods. The module possessed both pressurised and unpressurised segments, and featured a large, externally mounted synthetic aperture radar dish.<ref name="SSSM"/>{{rp|251–253}}
|}

=== Unpressurised elements ===
{{anchor|VDU}}
[[File:Mir unpressurised elements.jpg|thumb|The Travers radar antenna, ''Sofora'' girder, VDU thruster block, SPK unit and a ''Strela'' crane, alongside ''Kvant''-2 and ''Priroda'']]
In addition to the pressurised modules, ''Mir'' featured several external components. The largest component was the ''Sofora'' girder, a large scaffolding-like structure consisting of 20 segments which, when assembled, projected 14 metres from its mount on ''Kvant''-1. A self-contained thruster block, the VDU (Vynosnaya Dvigatyelnaya Ustanovka), was mounted on the end of ''Sofora'' and was used to augment the roll-control thrusters on the core module. The VDU's increased distance from ''Mir'''s axis allowed an 85% decrease in fuel consumption, reducing the amount of propellant required to orient the station.<ref name="SSSM"/>{{page number|date=February 2021}} A second girder, ''Rapana'', was mounted aft of ''Sofora'' on ''Kvant''-1. This girder, a small prototype of a structure intended to be used on ''Mir''-2 to hold large parabolic dishes away from the main station structure, was 5 metres long and used as a mounting point for externally mounted exposure experiments.<ref name="SSSM"/>{{page number|date=February 2021}}

To assist in moving objects around the exterior of the station during EVAs, ''Mir'' featured two [[Astronomy:Strela (crane)|''Strela'' cargo cranes]] mounted to the sides of the core module, used for moving spacewalking cosmonauts and parts. The cranes consisted of telescopic poles assembled in sections which measured around {{convert|6|ft|m|order=flip}} when collapsed, but when extended using a hand crank were {{convert|46|ft|m|order=flip}} long, meaning that all of the station's modules could be accessed during spacewalks.<ref>{{cite book|title=Leaving Earth: Space Stations, Rival Superpowers and the Quest for Interplanetary Travel|publisher=Henry (Joseph) Press|isbn=978-0-309-08548-9|url=https://books.google.com/books?id=0e2vl0sev2IC&pg=PA297|author=Robert Zimmerman|date=3 September 2003|page=297|access-date=27 February 2018|archive-date=5 August 2020|archive-url=https://web.archive.org/web/20200805233521/https://books.google.com/books?id=0e2vl0sev2IC&pg=PA297|url-status=live}}</ref>

Each module was fitted with external components specific to the experiments that were carried out within that module, the most obvious being the Travers antenna mounted to ''Priroda''. This synthetic aperture radar consisted of a large dish-like framework mounted outside the module, with associated equipment within, used for Earth observations experiments, as was most of the other equipment on ''Priroda'', including various radiometers and scan platforms.<ref name="MHH"/>{{page number|date=February 2021}} ''Kvant''-2 also featured several scan platforms and was fitted with a mounting bracket to which the cosmonaut manoeuvring unit, or ''Ikar'', was mated. This backpack was designed to assist cosmonauts in moving around the station and the planned ''Buran'' in a manner similar to the US [[Astronomy:Manned Maneuvering Unit|Manned Maneuvering Unit]], but it was only used once, during [[Astronomy:Mir EO-5|EO-5]].<ref name="SSSM"/>{{page number|date=February 2021}}

In addition to module-specific equipment, ''Kvant''-2, ''Kristall'', ''Spektr'' and ''Priroda'' were each equipped with one [[Astronomy:Lyappa arm|''Lyappa'' arm]], a robotic arm which, after the module had docked to the core module's forward port, grappled one of two fixtures positioned on the core module's docking node. The arriving module's docking probe was then retracted, and the arm raised the module so that it could be pivoted 90° for docking to one of the four radial docking ports.<ref name="MHH"/>{{page number|date=February 2021}}

===Power supply===
[[File:Spektr before collision - cropped.jpg|thumb|The four solar arrays on ''Spektr'']]
[[Physics:Photovoltaic system#Photovoltaic arrays|Photovoltaic (PV) arrays]] powered ''Mir''. The station used a 28&nbsp;[[Volt|volt]] [[Physics:Direct current|DC]] supply which provided 5-, 10-, 20- and 50-[[Ampere|amp]] taps. When the station was illuminated by sunlight, several solar arrays mounted on the pressurised modules provided power to ''Mir'''s systems and charged the nickel-cadmium storage batteries installed throughout the station.<ref name="SSSM"/> The arrays rotated in only one degree of freedom over a 180° arc, and tracked the Sun using [[Astronomy:Sun sensor|Sun sensor]]s and motors installed in the array mounts. The station itself also had to be oriented to ensure optimum illumination of the arrays. When the station's all-sky sensor detected that ''Mir'' had entered Earth's shadow, the arrays were rotated to the optimum angle predicted for reacquiring the Sun once the station passed out of the shadow. The batteries, each of 60&nbsp;[[Ampere hour|Ah]] capacity, were then used to power the station until the arrays recovered their maximum output on the day side of Earth.<ref name="SSSM"/>

The solar arrays themselves were launched and installed over a period of eleven years, more slowly than originally planned, with the station continually suffering from a shortage of power as a result. The first two arrays, each 38&nbsp;m<sup>2</sup> (409&nbsp;ft<sup>2</sup>) in area, were launched on the core module, and together provided a total of 9&nbsp;kW of power. A third, dorsal panel was launched on ''Kvant''-1 and mounted on the core module in 1987, providing a further 2&nbsp;kW from a 22&nbsp;m<sup>2</sup> (237&nbsp;ft<sup>2</sup>) area.<ref name="SSSM"/> ''Kvant''-2, launched in 1989, provided two 10&nbsp;m (32.8&nbsp;ft) long panels which supplied 3.5&nbsp;kW each, whilst ''Kristall'' was launched with two collapsible, 15&nbsp;m (49.2&nbsp;ft) long arrays (providing 4&nbsp;kW each) which were intended to be moved to ''Kvant''-1 and installed on mounts which were attached during a spacewalk by the [[Engineering:Soyuz TM-11|EO-8]] crew in 1991.<ref name="SSSM"/><ref name="MHH"/>

This relocation was begun in 1995, when the panels were retracted and the left panel installed on ''Kvant''-1. By this time all the arrays had degraded and were supplying much less power. To rectify this, ''Spektr'' (launched in 1995), which had initially been designed to carry two arrays, was modified to hold four, providing a total of 126&nbsp;m<sup>2</sup> (1360&nbsp;ft<sup>2</sup>) of array with a 16&nbsp;kW supply.<ref name="SSSM"/> Two further arrays were flown to the station on board the {{OV|104}} during [[Engineering:STS-74|STS-74]], carried on the docking module. The first of these, the ''Mir'' cooperative solar array, consisted of American photovoltaic cells mounted on a Russian frame. It was installed on the unoccupied mount on ''Kvant''-1 in May 1996 and was connected to the socket that had previously been occupied by the core module's dorsal panel, which was by this point barely supplying 1&nbsp;kW.<ref name="SSSM"/> The other panel, originally intended to be launched on ''Priroda'', replaced the ''Kristall'' panel on ''Kvant''-1 in November 1997, completing the station's electrical system.<ref name="SSSM"/>

===Orbit control===
[[File:MirOrbitalManoeuvres.svg|thumb|Graph showing the changing altitude of ''Mir'' from 19 February 1986 until 21 March 2001]]
''Mir'' was maintained in a near circular orbit with an average perigee of {{convert|354|km|mi|0|abbr=on}} and an average apogee of {{convert|374|km|mi|0|abbr=on}}, travelling at an average speed of 27,700&nbsp;km/h (17,200&nbsp;mph) and completing 15.7 orbits per day.<ref name="MirBIS"/><ref name="FinalBIS"/><ref name="OrbitCalc"/> As the station constantly lost altitude because of slight atmospheric drag, it needed to be boosted to a higher altitude several times each year. This boost was generally performed by Progress resupply vessels, although during the Shuttle-''Mir'' programme the task was performed by US Space Shuttles, and, prior to the arrival of [[Astronomy:Kvant-1|Kvant-1]], the engines on the core module could also accomplish the task.<ref name="SSSM"/>

Attitude<!--It's supposed to be ATTitude, meaning orientation - please don't change this to aLTitude.--> control was maintained by a combination of two mechanisms; in order to hold a set attitude<!--It's supposed to be ATTitude, meaning orientation - please don't change this to aLTitude.-->, a system of twelve [[Engineering:Control moment gyroscope|control moment gyroscope]]s (CMGs, or "gyrodynes") rotating at 10,000&nbsp;[[Revolutions per minute|rpm]] kept the station oriented, six CMGs being located in each of the ''Kvant-1'' and ''Kvant-2'' modules.<ref name="MHH"/><ref name="MirGyros">{{cite report|title=Further Analysis of the Microgravity Environment on Mir Space Station during Mir-16|date=June 1996|url=http://gltrs.grc.nasa.gov/cgi-bin/GLTRS/browse.pl?1996/TM-107239.html|author1=DeLombard R.|author2=Ryaboukha S.|author3=Hrovat K.|author4=Moskowitz M.|publisher=NASA|url-status=dead|archive-url=https://web.archive.org/web/20090507111807/http://gltrs.grc.nasa.gov/cgi-bin/GLTRS/browse.pl?1996%2FTM-107239.html|archive-date=7 May 2009}}</ref> When the attitude<!--It's supposed to be ATTitude, meaning orientation - please don't change this to aLTitude.--> of the station needed to be changed, the gyrodynes were disengaged, thrusters (including those mounted directly to the modules, and the VDU thruster used for roll control mounted to the ''Sofora'' girder) were used to attain the new attitude<!--It's supposed to be ATTitude, meaning orientation - please don't change this to aLTitude.--> and the CMGs were reengaged.<ref name="MirGyros"/> This was done fairly regularly depending on experimental needs; for instance, Earth or astronomical observations required that the instrument recording images be continuously aimed at the target, and so the station was oriented to make this possible.<ref name="SSSM"/> Conversely, materials processing experiments required the minimisation of movement on board the station, and so ''Mir'' would be oriented in a [[Physics:Gravity-gradient stabilization|gravity gradient]] attitude<!--It's supposed to be ATTitude, meaning orientation - please don't change this to aLTitude.--> for stability.<ref name="SSSM"/> Prior to the arrival of the modules containing these gyrodynes, the station's attitude<!--It's supposed to be ATTitude, meaning orientation - please don't change this to aLTitude.--> was controlled using thrusters located on the core module alone, and, in an emergency, the thrusters on docked Soyuz spacecraft could be used to maintain the station's orientation.<ref name="SSSM"/><ref name="Dragonfly"/>{{page number|date=February 2021}}

===Communications===
[[Social:Radio|Radio communications]] provided [[Telemetry|telemetry]] and scientific data links between ''Mir'' and the RKA Mission Control Centre (TsUP). Radio links were also used during [[Astronomy:Space rendezvous|rendezvous and docking procedures]] and for audio and video communication between crew members, flight controllers and family members. As a result, ''Mir'' was equipped with several communication systems used for different purposes. The station communicated directly with the ground via the ''Lira'' [[Engineering:Antenna (radio)|antenna]] mounted to the [[Astronomy:Mir Core Module|core module]]. The ''Lira'' antenna also had the capability to use the [[Engineering:Luch (satellite)|''Luch'']] data relay satellite system (which fell into disrepair in the 1990s) and the network of Soviet [[Engineering:Tracking ship|tracking ship]]s deployed in various locations around the world (which also became unavailable in the 1990s).<ref name="SSSM"/> [[Physics:Ultra high frequency|UHF radio]] was used by cosmonauts conducting EVAs. UHF was also employed by other spacecraft that docked to or undocked from the station, such as Soyuz, Progress, and the Space Shuttle, in order to receive commands from the TsUP and ''Mir'' crew members via the [[Astronomy:TORU|TORU]] system.<ref name="SSSM"/>

===Microgravity===
At ''Mir'''s orbital altitude, the force of Earth's gravity was 88% of sea level gravity. While the constant free fall of the station offered a perceived sensation of [[Physics:Weightlessness|weightlessness]], the onboard environment was not one of weightlessness or zero gravity. The environment was often described as [[Physics:Micro-g environment|microgravity]]. This state of perceived weightlessness was not perfect, being disturbed by five separate effects:<ref name="gravity">{{cite web|url=http://www.spaceflight.esa.int/users/downloads/userguides/physenv.pdf|title=European Users Guide to Low Gravity Platforms|access-date=13 July 2011|date=6 December 2005|publisher=European Space Agency|pages=1–3|archive-url=https://web.archive.org/web/20090327101925/http://www.spaceflight.esa.int/users/downloads/userguides/physenv.pdf|archive-date=27 March 2009}}</ref>
* The drag resulting from the residual atmosphere;
* Vibratory acceleration caused by mechanical systems and the crew on the station;
* Orbital corrections by the on-board gyroscopes (which spun at 10,000&nbsp;rpm, producing vibrations of 166.67&nbsp;[[Hertz|Hz]]<ref name="MirGyros"/>) or thrusters;
* [[Physics:Tidal force|Tidal force]]s. Any parts of ''Mir'' not at exactly the same distance from Earth tended to [[Physics:Gravity-gradient stabilization|follow separate orbits]]. As each point was physically part of the station, this was impossible, and so each component was subject to small accelerations from tidal forces;
* The differences in orbital plane between different locations on the station.

===Life support===
''Mir''<nowiki>'</nowiki>s [[Engineering:ISS ECLSS|environmental control and life support system]] (ECLSS) provided or controlled [[Physics:Atmospheric pressure|atmospheric pressure]], fire detection, oxygen levels, waste management and water supply. The highest priority for the ECLSS was the station's atmosphere, but the system also collected, processed, and stored waste and water produced and used by the crew—a process that recycles fluid from the sink, toilet, and condensation from the air. The ''Elektron'' system generated oxygen [[Chemistry:Electrolysis|electrolytically]], venting hydrogen to space. Bottled oxygen and [[Chemistry:Chemical oxygen generator|solid fuel oxygen generation]] (SFOG) canisters, a system known as [[Astronomy:Vika oxygen generator|''Vika'']], provided backup. Carbon dioxide was removed from the air by the ''[[Engineering:ISS ECLSS#Vozdukh|Vozdukh]]'' system.<ref name="SSSM"/> Other byproducts of human metabolism, such as methane from the intestines and ammonia from sweat, were removed by [[Physics:Activated carbon|activated charcoal]] filters. Similar systems are presently used on the ISS.

The atmosphere on ''Mir'' was similar to [[Earth:Atmosphere of Earth|Earth's]].<ref>{{cite web|url=http://science.howstuffworks.com/space-station2.htm|title=How Space Stations Work|last=Craig Freudenrich|publisher=Howstuffworks|date=20 November 2000|access-date=23 November 2008|archive-date=12 December 2008|archive-url=https://web.archive.org/web/20081212014934/http://science.howstuffworks.com/space-station2.htm|url-status=live}}</ref> Normal air pressure on the station was 101.3&nbsp;kPa (14.7&nbsp;[[Pounds per square inch|psi]]); the same as at sea level on Earth.<ref name="SSSM"/> An Earth-like atmosphere offers benefits for crew comfort.{{cn|date=September 2023}}

==International cooperation==
[[File:Ewald, Reinhold.jpg|thumb|upright|Reinhold Ewald (right) and Vasily Tsibliyev in the core module during Ewald's visit to ''Mir'']]
[[File:MIR Space Station Scale model.jpg|thumb|Scale model replica of the MIR Space Station at the Euro Space Center Belgium]]
===Interkosmos===
{{Main|Astronomy:Interkosmos}}
Interkosmos ({{lang-ru|ИнтерКосмос}}) was a Soviet Union space exploration programme which allowed members from countries allied with the Soviet Union to participate in crewed and uncrewed space exploration missions. Participation was also made available to governments of countries such as France and India.

Only the last three of the programme's fourteen missions consisted of an expedition to ''Mir'' but none resulted in an extended stay in the station:
* Muhammed Faris – [[Astronomy:Mir EP-1|EP-1]] (1987) {{flag|Syria}} {{flag|Turkey}} <ref name="EA-TM3">{{cite web|author=Mark Wade|url=http://www.astronautix.com/flights/soyuztm3.htm|title=Soyuz TM-3|publisher=[[Encyclopedia Astronautica]]|access-date=11 November 2010|url-status=dead|archive-url=https://web.archive.org/web/20100108040111/http://astronautix.com/flights/soyuztm3.htm|archive-date=8 January 2010}}{{unreliable source inline|date=February 2021}}</ref>{{unreliable source inline|date=February 2021}}
* Aleksandr Panayatov Aleksandrov – [[Astronomy:Mir EP-2|EP-2]] (1988) {{flag|Bulgaria|1971}}<ref name="EA-TM5">{{cite web|author=Mark Wade|url=http://www.astronautix.com/flights/mirep2.htm|title=Mir EP-2|publisher=Encyclopedia Astronautica|access-date=8 December 2010|url-status=dead|archive-url=https://web.archive.org/web/20100108025612/http://astronautix.com/flights/mirep2.htm|archive-date=8 January 2010}}{{unreliable source inline|date=February 2021}}</ref>{{unreliable source inline|date=February 2021}}
* Abdul Ahad Mohmand – [[Astronomy:Mir EP-3|EP-3]] (1988) {{flag|Afghanistan|1987}}<ref name="EA-TM6">{{cite web|author=Mark Wade|url=http://www.astronautix.com/flights/mirep3.htm|title=Mir EP-3|publisher=Encyclopedia Astronautica|access-date=8 December 2010|url-status=dead|archive-url=https://web.archive.org/web/20101129160600/http://astronautix.com/flights/mirep3.htm|archive-date=29 November 2010}}{{unreliable source inline|date=February 2021}}</ref>{{unreliable source inline|date=February 2021}}

===European involvement===
Various European astronauts visited ''Mir'' as part of several cooperative programmes:<ref name="ESApatches">{{cite web|url=http://esamultimedia.esa.int/docs/corporate/posterpatch.pdf|publisher=ESA|title=European Manned Spaceflight Patches|date=29 October 2009|access-date=15 December 2010|archive-date=18 January 2012|archive-url=https://web.archive.org/web/20120118010139/http://esamultimedia.esa.int/docs/corporate/posterpatch.pdf|url-status=live}}</ref>
* Jean-Loup Chrétien – ''Aragatz'' (1988) {{flag|France|1974}}
* Helen Sharman – [[Astronomy:Project Juno|Project Juno]] (1991) {{flag|UK}}
* Franz Viehböck – [[Engineering:Soyuz TM-13|Austromir '91]] (1991) {{flag|Austria}}
* Klaus-Dietrich Flade – [[Engineering:Soyuz TM-14|''Mir'' '92]] (1992) {{flag|Germany}}
* Michel Tognini – [[Engineering:Soyuz TM-15|''Antarès'']] (1992) {{flag|France|1974}}
* Jean-Pierre Haigneré – [[Engineering:Soyuz TM-17|''Altair'']] (1993) {{flag|France|1974}}
* Ulf Merbold – [[Engineering:Soyuz TM-20|Euromir '94]] (1994) {{flag|Germany}}
* Thomas Reiter – [[Engineering:Soyuz TM-22|Euromir '95]] (1995) {{flag|Germany}}
* Claudie Haigneré – [[Engineering:Soyuz TM-24|''Cassiopée'']] (1996) {{flag|France|1974}}
* Reinhold Ewald – [[Engineering:Soyuz TM-25|''Mir'' '97]] (1997) {{flag|Germany}}
* Léopold Eyharts – [[Engineering:Soyuz TM-27|''Pégase'']] (1998) {{flag|France|1974}}
* Ivan Bella – [[Engineering:Soyuz TM-29|''Stefanik'']] (1999) {{flag|Slovakia}}

===Shuttle–''Mir'' program===
{{Main|Astronomy:Shuttle–Mir Program}}
[[File:Shuttle-Mir Astronauts.jpg|thumb|The [[Astronomy:List of Mir visitors|seven NASA astronauts]] who carried out long-duration missions on ''Mir'']]
In the early 1980s, NASA planned to launch a modular space station called [[Astronomy:Space Station Freedom|''Freedom'']] as a counterpart to ''Mir'', while the Soviets were planning to construct ''Mir''-2 in the 1990s as a replacement for the station.<ref name="SSSM">{{cite book|author=David Harland|title=The Story of Space Station Mir|publisher=Springer-Verlag New York Inc|date=30 November 2004|location=New York|isbn=978-0-387-23011-5|url-access=registration|url=https://archive.org/details/storyofspacestat0000harl}}{{page number|date=February 2021}}</ref>{{page number|date=February 2021}} Because of budget and design constraints, ''Freedom'' never progressed past mock-ups and minor component tests and, with the fall of the Soviet Union and the end of the [[Astronomy:Space Race|Space Race]], the project was nearly cancelled entirely by the United States House of Representatives. The post-Soviet economic chaos in Russia also led to the cancellation of ''Mir''-2, though only after its base block, DOS-8, had been constructed.<ref name="SSSM"/> Similar budgetary difficulties were faced by other nations with space station projects, which prompted the US government to negotiate with European states, Russia, Japan, and Canada in the early 1990s to begin a collaborative project.<ref name="SSSM"/> In June 1992, American president George H. W. Bush and Russian president Boris Yeltsin agreed to cooperate on [[Astronomy:Space exploration|space exploration]]. The resulting ''Agreement between the United States of America and the Russian Federation Concerning Cooperation in the Exploration and Use of Outer Space for Peaceful Purposes'' called for a short joint space programme with one American [[Astronaut|astronaut]] deployed to the Russian space station ''Mir'' and two Russian [[Astronaut#Russia|cosmonauts]] deployed to a Space Shuttle.<ref name="SSSM"/>

In September 1993, US Vice President Al Gore Jr., and Russian Prime Minister Viktor Chernomyrdin announced plans for a new space station, which eventually became the [[Astronomy:International Space Station|ISS]].<ref name="gao">{{cite web|url=http://archive.gao.gov/t2pbat3/151975.pdf|title=''Space Station: Impact of the Expanded Russian Role on Funding and Research''|access-date=3 November 2006|author=Donna Heivilin|date=21 June 1994|publisher=[[Engineering:Government Accountability Office|Government Accountability Office]]|pages=1–2|archive-date=21 July 2011|archive-url=https://web.archive.org/web/20110721083656/http://archive.gao.gov/t2pbat3/151975.pdf|url-status=live}}</ref> They also agreed, in preparation for this new project, that the United States would be heavily involved in the ''Mir'' programme as part of an international project known as the [[Astronomy:Shuttle–Mir Program|Shuttle–Mir Program]]me.<ref name="SMB">{{cite web|title=Shuttle–Mir History/Background/How "Phase 1" Started|publisher=NASA|date=4 April 2004|author=Kim Dismukes|url=http://spaceflight.nasa.gov/history/shuttle-mir/history/h-b-start.htm|access-date=12 April 2007|archive-date=4 March 2016|archive-url=https://web.archive.org/web/20160304113151/http://spaceflight.nasa.gov/history/shuttle-mir/history/h-b-start.htm|url-status=dead}}</ref> The project, sometimes called "Phase One", was intended to allow the United States to learn from Russian experience in long-duration spaceflight and to foster a spirit of cooperation between the two nations and their space agencies, the US [[Organization:National Aeronautics and Space Administration|National Aeronautics and Space Administration]] (NASA) and the Russian Federal Space Agency (Roskosmos). The project prepared the way for further cooperative space ventures, specifically, "Phase Two" of the joint project, the construction of the ISS. The programme was announced in 1993; the first mission started in 1994, and the project continued until its scheduled completion in 1998. Eleven Space Shuttle missions, a joint Soyuz flight, and almost 1000 cumulative days in space for US astronauts occurred over the course of seven long-duration expeditions.

===Other visitors=== <!-- Note: Peter Rodney Llewellyn directs to this section -->
* Toyohiro Akiyama – [[Engineering:Soyuz TM-11|''Kosmoreporter'']] (1990) {{flag|Japan}}<ref name="SSSM"/>
* Chris Hadfield – [[Engineering:STS-74|STS-74]] (1995) {{flag|Canada}}<ref>{{cite web |title=Biography of Chris Hadfield |url=https://www.asc-csa.gc.ca/eng/astronauts/canadian/former/bio-chris-hadfield.asp |website=Canadian Space Agency |publisher=Government of Canada |access-date=8 May 2020 |date=22 July 2014 |quote=In November 1995 Hadfield served as Mission Specialist 1 on STS-74, NASA's second space shuttle mission to rendezvous and dock with the Russian Space Station Mir... the only Canadian to ever board Mir. |archive-date=9 June 2020 |archive-url=https://web.archive.org/web/20200609153228/https://www.asc-csa.gc.ca/eng/astronauts/canadian/former/bio-chris-hadfield.asp |url-status=live }}</ref>
* A British con artist, Peter Rodney Llewellyn, almost visited ''Mir'' in 1999 on a private contract after promising {{wipe|United States dollar}}100 million for the privilege.<ref>{{cite news|url=http://news.bbc.co.uk/1/hi/sci/tech/353467.stm|title=No Mir flight for British businessman|work=BBC News|date=27 May 1999|access-date=13 April 2007|archive-date=16 August 2007|archive-url=https://web.archive.org/web/20070816054737/http://news.bbc.co.uk/1/hi/sci/tech/353467.stm|url-status=live}}</ref><ref name="Wired">{{cite magazine|author=Polly Sprenger|title=UK Businessman Booted Off Mir|magazine=Wired|date=26 May 1999|url=http://archive.wired.com/science/discoveries/news/1999/05/19895|access-date=16 July 2015|archive-date=23 March 2021|archive-url=https://web.archive.org/web/20210323004543/https://www.wired.com/1999/05/uk-businessman-booted-off-mir/|url-status=live}}</ref>

==Life on board==
[[File:19970530 8l.jpg|thumb|left|Time exposure of ''Mir'' passing over Earth's surface, May 1997.]]
[[File:Mirspacestationtour.ogv|thumb|right|A video tour of ''Mir'' from September 1996, during STS-79]]
[[File:Mir node interior STS-84, 2.jpg|thumb|right|A view of the interior of the core module's docking node, showing the crowded nature of the station.]]
Inside, the {{convert|130|tonne|ST|adj=on}} ''Mir'' resembled a cramped labyrinth, crowded with hoses, cables and scientific instruments—as well as articles of everyday life, such as photos, children's drawings, books and a guitar. It commonly housed three crew members, but was capable of supporting as many as six for up to a month. The station was designed to remain in orbit for around five years; it remained in orbit for fifteen.<ref>{{cite web|title=One Thing After Another|url=http://discovermagazine.com/1998/jan/theyearinscience1326|work=Discover|access-date=5 February 2011|author=Fred Guterl|date=1 January 1998|archive-date=13 January 2011|archive-url=https://web.archive.org/web/20110113193128/http://discovermagazine.com/1998/jan/theyearinscience1326|url-status=live}}</ref> As a result, NASA astronaut John Blaha reported that, with the exception of ''[[Astronomy:Priroda|Priroda]]'' and ''[[Astronomy:Spektr|Spektr]]'', which were added late in the station's life, ''Mir'' did look used, which is to be expected given it had been lived in for ten to eleven years without being brought home and cleaned.<ref name="From Mir to Mars">{{cite web|url=https://www.pbs.org/safarchive/5_cool/5_mir/mir1.html|title=From Mir to Mars|publisher=Public Broadcasting Service|access-date=14 September 2008|archive-date=24 September 2015|archive-url=https://web.archive.org/web/20150924151702/http://www.pbs.org/safarchive/5_cool/5_mir/mir1.html|url-status=live}}</ref>

===Crew schedule===
The time zone used on board ''Mir'' was [[Moscow Time]] ([[UTC+03:00|UTC+03]]). The windows were covered during night hours to give the impression of darkness because the station experienced 16 sunrises and sunsets a day. A typical day for the crew began with a wake-up at 08:00, followed by two hours of personal hygiene and breakfast. Work was conducted from 10:00 until 13:00, followed by an hour of exercise and an hour's lunch break. Three more hours of work and another hour of exercise followed lunch, and the crews began preparing for their evening meal at about 19:00. The cosmonauts were free to do as they wished in the evening, and largely worked to their own pace during the day.<ref name="SSSM"/>

In their spare time, crews were able to catch up with work, observe the Earth below, respond to letters, drawings and other items brought from Earth (and give them an official stamp to show they had been aboard ''Mir''), or make use of the station's ham radio.<ref name="SSSM"/> Two amateur radio call signs, U1MIR and U2MIR, were assigned to ''Mir'' in the late 1980s, allowing amateur radio operators on Earth to communicate with the cosmonauts.<ref>{{cite web|url=http://users.tellurian.com/gjurrens/astrohams.html |title=Astronaut Hams |url-status=dead |archive-url=https://web.archive.org/web/20061230122251/http://users.tellurian.com/gjurrens/astrohams.html |archive-date=30 December 2006 }}</ref> The station was also equipped with a supply of books and films for the crew to read and watch.<ref name="Dragonfly"/>

NASA astronaut Jerry Linenger related how life on board ''Mir'' was structured and lived according to the detailed itineraries provided by ground control. Every second on board was accounted for and all activities were timetabled. After working some time on ''Mir'', Linenger came to feel that the order in which his activities were allocated did not represent the most logical or efficient order possible for these activities. He decided to perform his tasks in an order that he felt enabled him to work more efficiently, be less fatigued, and suffer less from stress. Linenger noted that his comrades on ''Mir'' did not "improvise" in this way, and as a medical doctor he observed the effects of stress on his comrades that he believed was the outcome of following an itinerary without making modifications to it. Despite this, he commented that his comrades performed all their tasks in a supremely professional manner.<ref name="OffPlanet"/>{{page number|date=February 2021}}

Astronaut Shannon Lucid, who set the record for longest stay in space by a woman while aboard ''Mir'' (surpassed by Sunita Williams 11 years later on the ISS), also commented about working aboard ''Mir'' saying "I think going to work on a daily basis on ''Mir'' is very similar to going to work on a daily basis on an outstation in Antarctica. The big difference with going to work here is the isolation, because you really are isolated. You don't have a lot of support from the ground. You really are on your own."<ref name="From Mir to Mars"/>

===Exercise===
[[File:Lucid on Treadmill in Russian Mir Space Station - GPN-2000-001034.jpg|thumb|Shannon Lucid exercises on a treadmill during her stay aboard ''Mir''.]]
The most significant adverse effects of long-term weightlessness are [[Medicine:Muscle atrophy|muscle atrophy]] and deterioration of the [[Biology:Skeleton|skeleton]], or [[Astronomy:Spaceflight osteopenia|spaceflight osteopenia]]. Other significant effects include fluid redistribution, a slowing of the cardiovascular system, decreased production of [[Biology:Red blood cell|red blood cell]]s, balance disorders, and a weakening of the [[Biology:Immune system|immune system]]. Lesser symptoms include loss of body mass, nasal congestion, sleep disturbance, excess [[Medicine:Flatulence|flatulence]], and puffiness of the face. These effects begin to reverse quickly upon return to the Earth.<ref name="JCB">{{cite book|author=Jay Buckey|title=Space Physiology|publisher=Oxford University Press USA|date=23 February 2006|isbn=978-0-19-513725-5}}{{page number|date=February 2021}}</ref>{{page number|date=February 2021}}

To prevent some of these effects, the station was equipped with two [[Engineering:Treadmill|treadmill]]s (in the core module and ''Kvant''-2) and a [[Engineering:Stationary bicycle|stationary bicycle]] (in the core module); each cosmonaut was to cycle the equivalent of {{convert|10|km|mi}} and run the equivalent of {{convert|5|km|mi}} per day.<ref name="SSSM"/> Cosmonauts used bungee cords to strap themselves to the treadmill. Researchers believe that exercise is a good countermeasure for the bone and muscle density loss that occurs in low-gravity situations.<ref>{{cite web|url=http://www.nasa.gov/mission_pages/station/behindscenes/colbert_feature.html|access-date=23 August 2009|title=Do Tread on Me|date=19 August 2009|author=Amiko Kauderer|publisher=NASA|archive-date=21 August 2009|archive-url=https://web.archive.org/web/20090821165909/http://www.nasa.gov/mission_pages/station/behindscenes/colbert_feature.html|url-status=live}}</ref>

===Hygiene===
[[File:Russian space toilet.JPG|thumb|upright|One of the space toilets used aboard ''Mir'']]
There were two [[Astronomy:Space toilet|space toilet]]s (ASUs) on ''Mir'', located in the [[Astronomy:Mir Core Module|core module]] and [[Astronomy:Kvant-2|''Kvant''-2]].<ref name="Dragonfly"/> They used a fan-driven suction system similar to the Space Shuttle Waste Collection System. The user is first fastened to the toilet seat, which was equipped with spring-loaded restraining bars to ensure a good seal. A lever operated a powerful fan and a suction hole slid open: the air stream carried the waste away. Solid waste was collected in individual bags which were stored in an aluminium container. Full containers were transferred to Progress spacecraft for disposal. Liquid waste was evacuated by a hose connected to the front of the toilet, with anatomically appropriate "urine funnel adapters" attached to the tube so both men and women could use the same toilet. Waste was collected and transferred to the Water Recovery System, where it could be recycled back into drinking water, but was usually used to produce oxygen via the ''Elektron'' system.<ref name="SSSM"/>

''Mir'' featured a shower, the ''Bania'', located in ''Kvant''-2. It was an improvement on the units installed in previous Salyut stations, but proved difficult to use due to the time required to set up, use, and stow. The shower, which featured a plastic curtain and fan to collect water via an airflow, was later converted into a steam room; it eventually had its plumbing removed and the space was reused. When the shower was unavailable, crew members washed using wet wipes, with soap dispensed from a toothpaste tube-like container, or using a washbasin equipped with a plastic hood, located in the core module. Crews were also provided with rinse-less shampoo and edible toothpaste to save water.<ref name="SSSM"/>

On a 1998 visit to ''Mir'', bacteria and larger organisms were found to have proliferated in water globules formed from moisture that had condensed behind service panels.<ref name = date>{{cite web|url=https://science.nasa.gov/science-news/science-at-nasa/2007/11may_locad3/|title=Preventing "Sick" Spaceships – Science Mission Directorate|website=science.nasa.gov|access-date=|archive-date=14 May 2017|archive-url=https://web.archive.org/web/20170514233537/https://science.nasa.gov/science-news/science-at-nasa/2007/11may_locad3|url-status=dead|first = Trudy E. |last = Bell |date = 11 May 2007}}</ref>

===Sleeping in space===
{{main|Astronomy:Sleep in space}}
[[File:Mir Crew Quarter.jpg|thumb|right|Cosmonaut Yury Usachov in his ''Kayutka'']]
The station provided two permanent crew quarters, the ''Kayutkas'', phonebox-sized booths set towards the rear of the core module, each featuring a tethered sleeping bag, a fold-out desk, a porthole, and storage for personal effects. Visiting crews had no allocated sleep module, instead attaching a sleeping bag to an available space on a wall; US astronauts installed themselves within ''[[Astronomy:Spektr|Spektr]]'' until a collision with a Progress spacecraft caused the depressurisation of that module.<ref name="SSSM"/> It was important that crew accommodations be well ventilated; otherwise, astronauts could wake up oxygen-deprived and gasping for air, because a bubble of their own exhaled carbon dioxide had formed around their heads.<ref name="ESALife">{{cite web|url=http://www.esa.int/esaHS/ESAH1V0VMOC_astronauts_0.html|publisher=ESA|access-date=28 October 2009|date=19 July 2004|title=Daily life|archive-date=13 February 2010|archive-url=https://web.archive.org/web/20100213144154/http://www.esa.int/esaHS/ESAH1V0VMOC_astronauts_0.html|url-status=live}}</ref>

===Food and drink===
Most of the food eaten by station crews was frozen, refrigerated or canned. Meals were prepared by the cosmonauts, with the help of a dietitian, before their flight to the station. The diet was designed to provide around 100&nbsp;g of [[Biology:Protein|protein]], 130&nbsp;g of [[Chemistry:Fat|fat]] and 330&nbsp;g of [[Chemistry:Carbohydrate|carbohydrate]]s per day, in addition to appropriate mineral and vitamin supplements. Meals were spaced out through the day to aid assimilation.<ref name="SSSM"/> Canned food such as jellied beef tongue was placed into a niche in the core module's table, where it could be warmed in 5–10 minutes. Usually, crews drank tea, coffee and fruit juices, but, unlike the ISS, the station also had a supply of cognac and vodka for special occasions.<ref name="Dragonfly"/>

===Microbiological environmental hazards===
In the 1990s samples of [[Earth:Extremophile|extremophile]] molds were taken from ''Mir''. Ninety species of micro-organisms were found in 1990, four years after the station's launch. By the time of its decommission in 2001, the number of known different micro-organisms had grown to 140. As space stations get older, the problems with contamination get worse.{{cn|date=December 2020}} Molds that develop aboard space stations can produce acids that degrade metal, glass and rubber.<ref>{{cite web|url=https://science.nasa.gov/science-news/science-at-nasa/2007/11may_locad3/|author=Trudy E. Bell|year=2007|title=Preventing "Sick" Spaceships|access-date=12 July 2017|archive-date=14 May 2017|archive-url=https://web.archive.org/web/20170514233537/https://science.nasa.gov/science-news/science-at-nasa/2007/11may_locad3|url-status=live}}</ref> The molds in ''Mir'' were found growing behind panels and inside air-conditioning equipment. The molds also caused a foul smell, which was often cited as visitors' strongest impression.<ref name="bbc2001">{{cite web|url=http://news.bbc.co.uk/2/hi/world/monitoring/media_reports/1209034.stm|title=Mutant fungus from space|date=8 March 2001|website=BBC|access-date=9 May 2015|archive-date=18 May 2015|archive-url=https://web.archive.org/web/20150518095038/http://news.bbc.co.uk/2/hi/world/monitoring/media_reports/1209034.stm|url-status=live}}</ref> Researchers in 2018 reported, after detecting the presence on the [[Astronomy:International Space Station|International Space Station]] (ISS) of five ''[[Biology:Enterobacter|Enterobacter bugandensis]]'' bacterial strains, none pathogenic to humans, that [[Biology:Microorganism|microorganism]]s on ISS should be carefully monitored to continue ensuring a medically healthy environment for the astronauts.<ref name="EA-20181122">{{cite web |author=BioMed Central |title=ISS microbes should be monitored to avoid threat to astronaut health |url=https://www.eurekalert.org/pub_releases/2018-11/bc-ims112018.php |date=22 November 2018 |work=EurekAlert! |access-date=25 November 2018 |archive-date=26 November 2018 |archive-url=https://web.archive.org/web/20181126005739/https://www.eurekalert.org/pub_releases/2018-11/bc-ims112018.php |url-status=live }}</ref><ref name="BMC-20181123">{{cite journal |author=Singh, Nitin K.|display-authors=0|title=Multi-drug resistant Enterobacter bugandensis species isolated from the International Space Station and comparative genomic analyses with human pathogenic strains |date=23 November 2018 |journal=BMC Microbiology |volume=18 |issue=1 |page=175 |doi=10.1186/s12866-018-1325-2 |pmid=30466389 |pmc=6251167 |doi-access=free }}</ref>

Some biologists were concerned about the mutant fungi being a major microbiological hazard for humans, and reaching Earth in the splashdown, after having been in an isolated environment for 15 years.<ref name="bbc2001"/>

==Station operations==

===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 [[Astronomy:Mir EO-28|EO-28]] to the 437-day flight of [[Biography:Valeri Polyakov|Valeri Polyakov]]), but generally lasted around six months.<ref name="SSSM"/> Principal expedition crews consisted of two or three crew members, who often launched as part of one expedition but returned with another (Polyakov launched with EO-14 and landed with EO-17).<ref name="SSSM"/> The principal expeditions were often supplemented with visiting crews who remained on the station during the week-long handover period between one crew and the next before returning with the departing crew, the station's life support system being able to support a crew of up to six for short periods.<ref name="SSSM"/><ref name="SoyuzUS">{{cite book|title=Soyuz: A Universal Spacecraft|year=2003|publisher=Springer-Praxis|isbn=978-1-85233-657-8|author1=Rex Hall  |author2=David Shayler |name-list-style=amp }}{{page number|date=February 2021}}</ref>{{page number|date=February 2021}} The station was occupied for a total of four distinct periods; 12 March–16 July 1986 ([[Astronomy:Mir EO-1|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 ([[Astronomy:Mir EO-28|EO-28]]).<ref name="SoyuzUS"/>{{page number|date=February 2021}} By the end, it had been [[Astronomy:List of Mir visitors|visited by 104 different people from twelve different nations]], making it the most visited spacecraft in history (a record later [[Astronomy:List of International Space Station visitors|surpassed by the ISS]]).<ref name="SSSM"/>

====Early existence====
[[File:Mir-kvant.jpg|thumb|The core module with ''Kvant''-1 and Soyuz TM-3]]
Due to pressure to launch the station on schedule, mission planners were left without Soyuz spacecraft or modules to launch to the station at first. It was decided to launch [[Engineering:Soyuz T-15|Soyuz T-15]] on a dual mission to both ''Mir'' and [[Engineering:Salyut 7|Salyut 7]].<ref name="Encyclopedia Astronautica">{{cite web|title=Mir complex|publisher=Encyclopedia Astronautica|author=Mark Wade|url=http://www.astronautix.com/m/mircomplex.html|access-date=19 November 2020|archive-date=23 March 2021|archive-url=https://web.archive.org/web/20210323004602/http://www.astronautix.com/m/mircomplex.html|url-status=dead}}{{unreliable source inline|date=February 2021}}</ref>{{unreliable source inline|date=February 2021}}

[[Biography:Leonid Kizim|Leonid Kizim]] and [[Biography:Vladimir Solovyov (cosmonaut)|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, [[Engineering:Progress 25|Progress 25]] and [[Engineering:Progress 26|Progress 26]].<ref name="Manned Astronautics Soyuz-T15">{{cite web|title=Spacecraft "Soyuz-T15" |publisher=Manned Astronautics |author=Alexander Anikeev |url=http://space.kursknet.ru/cosmos/english/machines/st15.sht |access-date=16 April 2007 |url-status=dead |archive-url=https://web.archive.org/web/20090301204034/http://space.kursknet.ru/cosmos/english/machines/st15.sht |archive-date=1 March 2009 }}</ref>

On 5 May 1986, they undocked from ''Mir'' for a day-long journey to Salyut 7. They spent 51 days there and gathered 400&nbsp;kg of scientific material from Salyut 7 for return to ''Mir''. While Soyuz T-15 was at Salyut 7, the uncrewed [[Engineering:Soyuz TM-1|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 [[Physics:Spectrometer|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.<ref name="Encyclopedia Astronautica mireo">{{cite web|title=Mir EO-1|publisher=Encyclopedia Astronautica|author=Mark Wade|url=http://www.astronautix.com/flights/mireo1.htm|access-date=18 April 2007|url-status=dead|archive-url=https://web.archive.org/web/20070407163641/http://astronautix.com/flights/mireo1.htm|archive-date=7 April 2007}}{{unreliable source inline|date=February 2021}}</ref>{{unreliable source inline|date=February 2021}}

The second expedition to ''Mir'', [[Astronomy:Mir EO-2|EO-2]], launched on [[Engineering:Soyuz TM-2|Soyuz TM-2]] on 5 February 1987. During their stay, the [[Astronomy:Kvant-1|''Kvant''-1]] module, launched on 30 March 1987, arrived. It was the first experimental version of a planned series of '37K' modules scheduled to be launched to ''Mir'' on ''Buran''. ''Kvant''-1 was originally planned to dock with [[Engineering:Salyut 7|Salyut 7]]; due to technical problems during its development, it was reassigned to ''Mir''. The module carried the first set of six gyroscopes for attitude<!--It's supposed to be ATTitude, meaning orientation - please don't change this to aLTitude.--> control. The module also carried instruments for X-ray and ultraviolet astrophysical observations.<ref name="MHH"/>

The initial rendezvous of the ''Kvant''-1 module with ''Mir'' on 5 April 1987 was troubled by the failure of the onboard control system. After the failure of the second attempt to dock, the resident cosmonauts, [[Biography:Yuri Romanenko|Yuri Romanenko]] and [[Biography:Aleksandr Laveykin|Aleksandr Laveykin]], conducted an [[Astronomy:Extravehicular activity|EVA]] to fix the problem. They found a trash bag which had been left in orbit after the departure of one of the previous cargo ships and was now located between the module and the station, which prevented the docking. After removing the bag, docking was completed on 12 April.<ref name="Encyclopedia Astronautica mireo2">{{cite web|title=Mir EO-2|publisher=Encyclopedia Astronautica|author=Mark Wade|url=http://www.astronautix.com/flights/mireo2.htm|access-date=18 April 2007|url-status=dead|archive-url=https://web.archive.org/web/20070409041745/http://astronautix.com/flights/mireo2.htm|archive-date=9 April 2007}}{{unreliable source inline|date=February 2021}}</ref>{{unreliable source inline|date=February 2021}}<ref name="RussianSpaceweb.com Kvant-1">{{cite web|title=Spacecraft: Manned: Mir: Kvant-1 Module |publisher=RussianSpaceweb.com |author=Anatoly Zak |url=http://www.russianspaceweb.com/mir_kvant.html |access-date=16 April 2007 |url-status=dead |archive-url=https://web.archive.org/web/20070424231617/http://www.russianspaceweb.com/mir_kvant.html |archive-date=24 April 2007 }}</ref>

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 [[Astronomy:Mir EO-4|EO-4]] on [[Engineering:Soyuz TM-7|Soyuz TM-7]] on 27 April 1989 the station was again left unoccupied.<ref name="SSSM"/>

====Third start====
The launch of [[Engineering:Soyuz TM-8|Soyuz TM-8]] on 5 September 1989 marked the beginning of the longest human presence in space, until 23 October 2010, when this record was surpassed by the ISS.<ref name="Mirrecord"/> It also marked the beginning of ''Mir's'' second expansion. The [[Astronomy:Kvant-2|Kvant-2]] and ''[[Astronomy:Kristall|Kristall]]'' modules were now ready for launch. Alexander Viktorenko and [[Biography:Aleksandr Serebrov|Aleksandr Serebrov]] docked with ''Mir'' and brought the station out of its five-month hibernation. On 29 September the cosmonauts installed equipment in the docking system in preparation for the arrival of ''Kvant''-2, the first of the 20&nbsp;[[Tonne|tonne]] add-on modules based on the TKS spacecraft from the [[Astronomy:Almaz|Almaz]] programme.<ref name="Encyclopedia Astronautica mireo5">{{cite web|title=Mir EO-5|publisher=Encyclopedia Astronautica|author=Mark Wade|url=http://www.astronautix.com/flights/mireo5.htm|access-date=18 April 2007|url-status=dead|archive-url=https://web.archive.org/web/20070409191451/http://astronautix.com/flights/mireo5.htm|archive-date=9 April 2007 }}{{unreliable source inline|date=February 2021}}</ref>{{unreliable source inline|date=February 2021}}

[[File:Mir Kvant 1-Base Block-Kvant 2.jpg|thumb|''Mir'' following the arrival of ''Kvant''-2 in 1989]]
After a 40-day delay caused by faulty computer chips, ''Kvant''-2 was launched on 26 November 1989. After problems deploying the craft's solar array and with the automated docking systems on both ''Kvant''-2 and ''Mir'', the new module was docked manually on 6 December. ''Kvant''-2 added a second set of [[Engineering:Control moment gyroscope|control moment gyroscope]]s (CMGs, or "gyrodynes") to ''Mir'', and brought the new life support systems for recycling water and generating oxygen, reducing dependence on ground resupply. The module featured a large airlock with a one-metre hatch. A special backpack unit (known as ''Ikar''), an equivalent of the US [[Astronomy:Manned Maneuvering Unit|Manned Maneuvering Unit]], was located inside ''Kvant''-2's airlock.<ref name="Encyclopedia Astronautica mireo5"/><ref name="russianspaceweb.com Kvant-2">{{cite web|title=Spacecraft: Manned: Mir: Kvant-2 Module |publisher=RussianSpaceWeb.com |author=Anatoly Zak |url=http://www.russianspaceweb.com/mir_kvant-2.html |access-date=18 April 2007 |url-status=dead |archive-url=https://web.archive.org/web/20070424232442/http://www.russianspaceweb.com/mir_kvant-2.html |archive-date=24 April 2007 }}</ref>

[[Engineering:Soyuz TM-9|Soyuz TM-9]] launched [[Astronomy:Mir EO-6|EO-6]] crew members [[Biography:Anatoly Solovyev|Anatoly Solovyev]] and [[Biography:Aleksandr Nikolayevich Balandin|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<!--It's supposed to be ATTitude - please don't change this to aLTitude.--> 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.<ref name="Encyclopedia Astronautica mireo6">{{cite web|title=Mir EO-6|publisher=Encyclopedia Astronautica|author=Mark Wade|url=http://www.astronautix.com/flights/mireo6.htm|access-date=19 April 2007|url-status=dead|archive-url=https://web.archive.org/web/20070411092726/http://astronautix.com/flights/mireo6.htm|archive-date=11 April 2007}}{{unreliable source inline|date=February 2021}}</ref>{{unreliable source inline|date=February 2021}}

''Kristall'' contained furnaces for use in producing crystals under microgravity conditions (hence the choice of name for the module). The module was also equipped with biotechnology research equipment, including a small greenhouse for plant cultivation experiments which was equipped with a source of light and a feeding system, in addition to equipment for astronomical observations. The most obvious features of the module were the two [[Astronomy:Androgynous Peripheral Attach System|Androgynous Peripheral Attach System]] (APAS-89) docking ports designed to be compatible with the ''Buran'' spacecraft. Although they were never used in a ''Buran'' docking, they were useful later during the Shuttle-''Mir'' programme, providing a berthing location for US [[Engineering:Space Shuttle|Space Shuttle]]s.<ref name="russianspaceweb.com Kristall">{{cite web|title=Spacecraft: Manned: Mir: Kristall Module |publisher=RussianSpaceWeb.com |author=Anatoly Zak |url=http://www.russianspaceweb.com/mir_kristall.html |date=25 May 2010 |access-date=17 December 2010 |url-status=dead |archive-url=https://web.archive.org/web/20110514002915/http://www.russianspaceweb.com/mir_kristall.html |archive-date=14 May 2011 }}</ref>

The [[Astronomy:Mir EO-7|EO-7]] relief crew arrived aboard [[Engineering:Soyuz TM-10|Soyuz TM-10]] on 3 August 1990. The new crew arrived at ''Mir'' with [[Biology:Quail|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&nbsp;kg of experiment results and industrial products, in Soyuz TM-9.<ref name="Encyclopedia Astronautica mireo6"/> Two more expeditions, [[Astronomy:Mir EO-8|EO-8]] and EO-9, continued the work of their predecessors whilst tensions grew back on Earth.

====Post-Soviet period====
[[File:Mir from Soyuz TM-17.jpg|thumb|A view of ''Mir'' from Soyuz TM-17 on 3 July 1993 showing ongoing docking operations at the station]]
The EO-10 crew, launched aboard [[Engineering:Soyuz TM-13|Soyuz TM-13]] on 2 October 1991, was the last crew to launch from the USSR and continued the occupation of ''Mir'' during the fall of the Soviet Union. The crew launched as Soviet citizens and returned to Earth on 25 March 1992 as Russians. The newly formed Russian Federal Space Agency (Roscosmos) was unable to finance the unlaunched ''[[Astronomy:Spektr|Spektr]]'' and ''[[Astronomy:Priroda|Priroda]]'' modules, instead putting them into storage and ending ''Mir's'' second expansion.<ref name="Encyclopedia Astronautica mireo10">{{cite web|title=Mir EO-10|publisher=Encyclopedia Astronautica|author=Mark Wade|url=http://www.astronautix.com/flights/mireo10.htm|access-date=19 April 2007|url-status=dead|archive-url=https://web.archive.org/web/20070407211042/http://astronautix.com/flights/mireo10.htm|archive-date=7 April 2007}}{{unreliable source inline|date=February 2021}}</ref>{{unreliable source inline|date=February 2021}}<ref name="Encyclopedia Astronautica Spektr">{{cite web|title=Spektr|publisher=Encyclopedia Astronautica|author=Mark Wade|url=http://www.astronautix.com/craft/spektr.htm|access-date=21 April 2007|url-status=dead|archive-url=https://web.archive.org/web/20070407052343/http://astronautix.com/craft/spektr.htm|archive-date=7 April 2007}}{{unreliable source inline|date=February 2021}}</ref>{{unreliable source inline|date=February 2021}}<ref name="Encyclopedia Astronautica Priroda">{{cite web|title=Priroda|publisher=Encyclopedia Astronautica|author=Mark Wade|url=http://www.astronautix.com/craft/priroda.htm|access-date=21 April 2007|url-status=dead|archive-url=https://web.archive.org/web/20070410031659/http://astronautix.com/craft/priroda.htm|archive-date=10 April 2007}}{{unreliable source inline|date=February 2021}}</ref>{{unreliable source inline|date=February 2021}}

The first human mission flown from an independent Kazakhstan was [[Engineering:Soyuz TM-14|Soyuz TM-14]], launched on 17 March 1992, which carried the EO-11 crew to ''Mir'', docking on 19 March before the departure of Soyuz TM-13. On 17 June, Russian President Boris Yeltsin and US President George H. W. Bush announced what would later become the Shuttle-''Mir'' programme, a cooperative venture which proved useful to the cash-strapped Roskosmos (and led to the eventual completion and launch of ''Spektr'' and ''Priroda''). [[Astronomy:Mir EO-12|EO-12]] followed in July, alongside a brief visit by French astronaut Michel Tognini.<ref name="SoyuzUS"/>{{page number|date=February 2021}} The following crew, EO-13, began preparations for the Shuttle-''Mir'' programme by flying to the station in a modified spacecraft, [[Engineering:Soyuz TM-16|Soyuz TM-16]] (launched on 26 January 1993), which was equipped with an APAS-89 docking system rather than the usual probe-and-drogue, enabling it to dock to ''Kristall'' and test the port which would later be used by US Space Shuttles. The spacecraft also enabled controllers to obtain data on the dynamics of docking a spacecraft to a space station off the station's longitudinal axis, in addition to data on the structural integrity of this configuration via a test called ''Rezonans'' conducted on 28 January. [[Engineering:Soyuz TM-15|Soyuz TM-15]], meanwhile, departed with the EO-12 crew on 1 February.<ref name="SoyuzUS"/>{{page number|date=February 2021}}

Throughout the period following the collapse of the USSR, crews on ''Mir'' experienced occasional reminders of the economic chaos occurring in Russia. The initial cancellation of ''Spektr'' and ''Priroda'' was the first such sign, followed by the reduction in communications as a result of the fleet of [[Engineering:Tracking ship|tracking ship]]s being withdrawn from service by {{wipe|Ukraine}}. The new Ukrainian government also vastly raised the price of the ''Kurs'' docking systems, manufactured in [[Place:Kyiv|Kyiv]]{{spaced ndash}}the Russians' attempts to reduce their dependence on ''Kurs'' would later lead to accidents during TORU tests in 1997. Various Progress spacecraft had parts of their cargoes missing, either because the consumable in question had been unavailable, or because the ground crews at Baikonur had looted them. The problems became particularly obvious during the launch of the EO-14 crew aboard [[Engineering:Soyuz TM-17|Soyuz TM-17]] in July; shortly before launch there was a black-out at the pad, and the power supply to the nearby city of Leninsk failed an hour after launch.<ref name="SSSM"/><ref name="SoyuzUS"/>{{page number|date=February 2021}} Nevertheless, the spacecraft launched on time and arrived at the station two days later. All of ''Mir''<nowiki>'</nowiki>s ports were occupied, and so Soyuz TM-17 had to station-keep 200 metres away from the station for half an hour before docking while [[Engineering:Progress M-18|Progress M-18]] vacated the core module's front port and departed.<ref name="SoyuzUS"/>{{page number|date=February 2021}}

The EO-13 crew departed on 22 July, and soon after ''Mir'' passed through the annual [[Astronomy:Perseids|Perseid]] [[Astronomy:Meteor shower|meteor shower]], during which the station was hit by several particles. A spacewalk was conducted on 28 September to inspect the station's hull, but no serious damage was reported. [[Engineering:Soyuz TM-18|Soyuz TM-18]] arrived on 10 January 1994 carrying the EO-15 crew (including [[Biography:Valeri Polyakov|Valeri Polyakov]], who was to remain on ''Mir'' for 14 months), and [[Engineering:Soyuz TM-17|Soyuz TM-17]] left on 14 January. The undocking was unusual in that the spacecraft was to pass along ''Kristall'' in order to obtain photographs of the APAS to assist in the training of space shuttle pilots. Due to an error in setting up the control system, the spacecraft struck the station a glancing blow during the manoeuvre, scratching the exterior of ''Kristall''.<ref name="SoyuzUS"/>{{page number|date=February 2021}}

On 3 February 1994, ''Mir'' veteran [[Biography:Sergei Krikalev|Sergei Krikalev]] became the first Russian cosmonaut to launch on a US spacecraft, flying on {{OV|103}} during [[Engineering:STS-60|STS-60]].<ref>{{cite web|url=http://science.ksc.nasa.gov/shuttle/missions/sts-60/mission-sts-60.html|title=STS-60 Mission Summary|date=29 June 2001|publisher=NASA|access-date=10 January 2014|archive-date=3 March 2016|archive-url=https://web.archive.org/web/20160303213447/http://science.ksc.nasa.gov/shuttle/missions/sts-60/mission-sts-60.html|url-status=live}}</ref>

The launch of [[Engineering:Soyuz TM-19|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 [[Engineering:Soyuz TM-20|Soyuz TM-20]].<ref name="SoyuzUS"/>{{page number|date=February 2021}}

====Shuttle–''Mir''====
{{Main|Astronomy:Shuttle–Mir Program}}
[[File:Atlantis docked to MIR - GPN-2000-001315.jpg|thumb|{{OV|104}} docked to ''Mir'' on STS-71.]]
The 3 February launch of {{OV|103}}, flying [[Engineering:STS-63|STS-63]], opened operations on ''Mir'' for 1995. Referred to as the "near-''Mir''" mission, the mission saw the first rendezvous of a Space Shuttle with ''Mir'' as the orbiter approached within {{convert|37|ft|m}} of the station as a dress rehearsal for later docking missions and for equipment testing.<ref name="SMH Flights">{{cite web|title=Shuttle–Mir History/Shuttle Flights and Mir Increments|publisher=NASA|url=http://spaceflight.nasa.gov/history/shuttle-mir/history/h-flights.htm|access-date=30 March 2007 |archive-date= 28 September 2015|archive-url=https://web.archive.org/web/20150928151002/http://spaceflight.nasa.gov/history/shuttle-mir/history/h-flights.htm|url-status=dead}}</ref><ref>{{cite web|title=STS-63 Mission Summary|author=Jim Dumoulin|publisher=NASA|date=29 June 2001|url=http://science.ksc.nasa.gov/shuttle/missions/sts-63/mission-sts-63.html|access-date=30 March 2007|archive-date=20 March 2009|archive-url=https://web.archive.org/web/20090320085830/http://science.ksc.nasa.gov/shuttle/missions/sts-63/mission-sts-63.html|url-status=live}}</ref><ref>{{cite news|author=Kathy Sawyer|title=US & Russia Find Common Ground in Space – Nations Overcome Hurdles in Ambitious Partnership|newspaper=Washington Post|page=a1|date=29 January 1995 |publisher= [[Organization:NewsBank|NewsBank]]}}</ref> Five weeks after ''Discovery''{{'s}} departure, the EO-18 crew, including the first US cosmonaut Norman Thagard, arrived in [[Engineering:Soyuz TM-21|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 ''[[Astronomy:Spektr|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 {{OV|104}} following the first Shuttle–''Mir'' docking mission, [[Engineering:STS-71|STS-71]].<ref name="SSSM"/><ref name="Dragonfly">{{cite book|author=Bryan Burrough|date=7 January 1998 |title=Dragonfly: NASA and the Crisis Aboard Mir|place=London, UK|publisher=Fourth Estate Ltd.|isbn=978-1-84115-087-1}}{{page number|date=February 2021}}</ref>{{page number|date= February 2021}} ''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.<ref>{{cite book|author1=David Scott  |author2=Alexei Leonov |name-list-style=amp |title=Two Sides of the Moon|publisher=Pocket Books|date=30 April 2005 |isbn= 978-0-7434-5067-6}}</ref> The orbiter delivered the [[Astronomy:Mir EO-19|EO-19]] crew and returned the EO-18 crew to Earth.<ref name="SMH Flights"/><ref>{{cite web|title=STS-71 Mission Summary |author= Jim Dumoulin|publisher=NASA|date=29 June 2001|url=http://science.ksc.nasa.gov/shuttle/missions/sts-71/mission-sts-71.html|access-date=30 March 2007|archive-date=29 March 2015 |archive-url= https://web.archive.org/web/20150329042625/http://science.ksc.nasa.gov/shuttle/missions/sts-71/mission-sts-71.html|url-status=live}}</ref><ref>{{cite news|author=Nick Nuttall |title= Shuttle homes in for Mir docking|newspaper=The Times|date=29 June 1995|publisher=NewsBank}}</ref> The [[Astronomy:Mir EO-20|EO-20]] crew were launched on 3 September, followed in November by the arrival of the docking module during [[Engineering:STS-74|STS-74]].<ref name="STS-74">{{cite web|title=STS-74 Mission Summary|author=Jim Dumoulin|publisher=NASA|date=29 June 2001|url-status= dead|url= http://science.ksc.nasa.gov/shuttle/missions/sts-74/mission-sts-74.html |access-date=|archive-date=20 December 2016|archive-url=https://web.archive.org/web/20161220034436/http://science.ksc.nasa.gov/shuttle/missions/sts-74/mission-sts-74.html}}</ref><ref name="SMH Flights"/><ref>{{cite web|title=CSA – STS-74 – Daily Reports |publisher=Canadian Space Agency |date=30 October 1999 |url=http://www.asc-csa.gc.ca/eng/missions/sts-074/reports.asp |access-date=17 September 2009 |url-status=dead |archive-url=https://web.archive.org/web/20110716061546/http://www.asc-csa.gc.ca/eng/missions/sts-074/reports.asp |archive-date=16 July 2011 }}</ref><ref>{{cite news|author=William Harwood|title=Space Shuttle docks with Mir – Atlantis uses manoeuvres similar to those needed for construction|newspaper=Washington Post|page=a3|date=15 November 1995|publisher=NewsBank}}</ref>

The two-man [[Astronomy:Mir EO-21|EO-21]] crew was launched on 21 February 1996 aboard [[Engineering:Soyuz TM-23|Soyuz TM-23]] and were soon joined by US crew member Shannon Lucid, who was brought to the station by ''Atlantis'' during [[Engineering:STS-76|STS-76]]. This mission saw the first joint US spacewalk on ''Mir'' take place deploying the [[Astronomy:Mir Environmental Effects Payload|Mir Environmental Effects Payload]] package on the docking module.<ref>{{cite news|author=William Harwood|title=Shuttle becomes hard-hat area; spacewalking astronauts practice tasks necessary to build station|newspaper=Washington Post|page=a3|date=28 March 1996|publisher=NewsBank}}</ref> 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'', ''[[Astronomy:Priroda|Priroda]]'', the station's final module, arrived as did French visitor Claudie Haigneré flying the ''Cassiopée'' mission. The flight aboard [[Engineering:Soyuz TM-24|Soyuz TM-24]] also delivered the EO-22 crew of Valery Korzun and Aleksandr Kaleri.<ref name="SSSM"/><ref name="SMH Flights"/><ref>{{cite web|title=STS-76 Mission Summary|author=Jim Dumoulin|publisher=NASA|date=29 June 2001|url=http://science.ksc.nasa.gov/shuttle/missions/sts-76/mission-sts-76.html|access-date=30 March 2007|archive-url=https://web.archive.org/web/20130806102139/http://science.ksc.nasa.gov/shuttle/missions/sts-76/mission-sts-76.html|archive-date=6 August 2013|url-status=dead}}</ref>

Lucid's stay aboard ''Mir'' ended with the flight of ''Atlantis'' on [[Engineering:STS-79|STS-79]], which launched on 16 September. This, the fourth docking, saw John Blaha transferring onto ''Mir'' to take his place as resident US astronaut. His stay on the station improved operations in several areas, including transfer procedures for a docked space shuttle, "hand-over" procedures for long-duration American crew members and "ham" amateur radio communications, and also saw 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 [[Engineering:STS-81|STS-81]] in January 1997, at which point he was replaced by [[Medicine:Physician|physician]] Jerry Linenger.<ref name="SMH Flights"/><ref>{{cite web|title=STS-79 Mission Summary|author=Jim Dumoulin|publisher=NASA|date=29 June 2001|url=http://science.ksc.nasa.gov/shuttle/missions/sts-79/mission-sts-79.html|access-date=30 March 2007|archive-date=18 May 2007|archive-url=https://web.archive.org/web/20070518135705/http://science.ksc.nasa.gov/shuttle/missions/sts-79/mission-sts-79.html|url-status=live}}</ref><ref name="STS-81">{{cite web|title=STS-81 Mission Summary|author=Jim Dumoulin|publisher=NASA|date=29 June 2001|url=http://science.ksc.nasa.gov/shuttle/missions/sts-81/mission-sts-81.html|access-date=30 March 2007|archive-date=20 May 2007|archive-url=https://web.archive.org/web/20070520090649/http://science.ksc.nasa.gov/shuttle/missions/sts-81/mission-sts-81.html|url-status=live}}</ref> 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 [[Engineering:Orlan space suit|Orlan-M]] spacesuit alongside Russian cosmonaut Vasili Tsibliyev, flying [[Astronomy:Mir EO-23|EO-23]]. All three crew members of EO-23 performed a "fly-around" in [[Engineering:Soyuz TM-25|Soyuz TM-25]] spacecraft.<ref name="SSSM"/> Linenger and his Russian crewmates Vasili Tsibliyev and Aleksandr Lazutkin faced several difficulties during the mission, including the most severe fire aboard an orbiting spacecraft (caused by a malfunctioning [[Astronomy:Vika oxygen generator|''Vika'']]), failures of various systems, a near collision with [[Engineering:Progress M-33|Progress M-33]] during a long-distance TORU test and a total loss of station electrical power. The power failure also caused a loss of [[Astronomy:Spacecraft attitude control|attitude control]], which led to an uncontrolled "tumble" through space.<ref name="SSSM"/><ref name="Dragonfly"/>{{page number|date=February 2021}}<ref name="OffPlanet">{{cite book|author=Jerry Linenger|date=1 January 2001|title=Off the Planet: Surviving Five Perilous Months Aboard the Space Station Mir|url=https://archive.org/details/offplanetsurvivi00line|url-access=registration|place=New York, US|publisher=McGraw-Hill|isbn=978-0-07-137230-5}}{{page number|date=February 2021}}</ref>{{page number|date=February 2021}}<ref name="SMH Flights"/>

[[File:Damaged Spektr solar array.jpg|thumb|Damaged solar arrays on the ''Mir'' ''Spektr'' module following a collision with Progress M-34 in September 1997.]]
Linenger was succeeded by Anglo-American astronaut Michael Foale, carried up by ''Atlantis'' on [[Engineering:STS-84|STS-84]], alongside Russian mission specialist Elena Kondakova. Foale's increment proceeded fairly normally until 25 June when during the second test of the ''Progress'' manual docking system, [[Astronomy:TORU|TORU]], [[Engineering:Progress M-34|Progress M-34]] collided with solar arrays on the ''[[Astronomy:Spektr|Spektr]]'' module and crashed into the module's outer shell, puncturing the module and causing depressurisation on the station. Only quick actions on the part of the crew, cutting cables leading to the module and closing ''Spektr's'' hatch, prevented the crews having to abandon the station in [[Engineering:Soyuz TM-25|Soyuz TM-25]]. Their efforts stabilised the station's air pressure, whilst the pressure in ''Spektr'', containing many of Foale's experiments and personal effects, dropped to a vacuum.<ref name="Dragonfly"/>{{page number|date=February 2021}}<ref name="SMH Flights"/> In an effort to restore some of the power and systems lost following the isolation of ''Spektr'' and to attempt to locate the leak, [[Astronomy:Mir EO-24|EO-24]] commander [[Biography:Anatoly Solovyev|Anatoly Solovyev]] and [[Engineering:Flight engineer|flight engineer]] Pavel Vinogradov carried out a risky salvage operation later in the flight, entering the empty module during a so-called "intra-vehicular activity" or "IVA" spacewalk and inspecting the condition of hardware and running cables through a special hatch from ''Spektr's'' systems to the rest of the station. Following these first investigations, Foale and Solovyev conducted a 6-hour EVA outside ''Spektr'' to inspect the damage.<ref name="SMH Flights"/><ref>{{Cite news|author=David Hoffman|title=Crucial Mir spacewalk carries high hopes – continued Western support could hinge on mission's success|newspaper=Washington Post|pages=a1|date=22 August 1997}}</ref>

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.<ref name="OffPlanet"/>{{page number|date=February 2021}} The next flight to ''Mir'', [[Engineering:STS-86|STS-86]], carried David Wolf aboard ''Atlantis''. During the orbiter's stay, Titov and Parazynski conducted a spacewalk to affix a cap to the docking module for a future attempt by crew members to seal the leak in ''Spektr''{{'}}s hull.<ref name="SMH Flights"/><ref>{{cite web|title=STS-86 Mission Summary|author=Jim Dumoulin|publisher=NASA|date=29 June 2001|url=http://science.ksc.nasa.gov/shuttle/missions/sts-86/mission-sts-86.html|access-date=30 March 2007|archive-date=3 March 2016|archive-url=https://web.archive.org/web/20160303230243/http://science.ksc.nasa.gov/shuttle/missions/sts-86/mission-sts-86.html|url-status=live}}</ref> Wolf spent 119 days aboard ''Mir'' with the EO-24 crew and was replaced during [[Engineering:STS-89|STS-89]] with Andy Thomas, who carried out the last US expedition on ''Mir''.<ref name="SMH Flights"/><ref>{{cite web|title=STS-89 Mission Summary|author=Jim Dumoulin|publisher=NASA|date=29 June 2001|url=http://science.ksc.nasa.gov/shuttle/missions/sts-89/mission-sts-89.html|access-date=30 March 2007|archive-date=4 March 2016|archive-url=https://web.archive.org/web/20160304062707/http://science.ksc.nasa.gov/shuttle/missions/sts-89/mission-sts-89.html|url-status=live}}</ref> The EO-25 crew arrived in [[Engineering:Soyuz TM-27|Soyuz TM-27]] in January 1998 before Thomas returned to Earth on the final Shuttle–''Mir'' mission, [[Engineering:STS-91|STS-91]].<ref name="SMH Flights"/><ref>{{cite web|title=STS-91 Mission Summary|author=Jim Dumoulin|publisher=NASA|date=29 June 2001|url=http://science.ksc.nasa.gov/shuttle/missions/sts-91/mission-sts-91.html|access-date=30 March 2007|archive-date=4 March 2016|archive-url=https://web.archive.org/web/20160304111001/http://science.ksc.nasa.gov/shuttle/missions/sts-91/mission-sts-91.html|url-status=live}}</ref><ref>{{cite news|author=William Harwood|title=Final American returns from Mir|newspaper=Washington Post|page=a12|date=13 June 1998|publisher=NewsBank}}</ref>

====Final days and deorbit====
{{main|Astronomy:Deorbit of Mir}}
[[File:Mir reentry photo.jpg|thumb|upright|''Mir'' breaks up in Earth's atmosphere over the [[Earth:South Pacific Ocean|South Pacific]] 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.<ref name="SSSM"/> The EO-26 crew of Gennady Padalka and Sergei Avdeyev arrived on 15 August in [[Engineering:Soyuz TM-28|Soyuz TM-28]], alongside physicist Yuri Baturin, who departed with the EO-25 crew on 25 August in [[Engineering:Soyuz TM-27|Soyuz TM-27]]. The crew carried out two spacewalks, one inside ''Spektr'' to reseat some power cables and another outside to set up experiments delivered by [[Engineering:Progress M-40|Progress M-40]], which also carried a large amount of propellant to begin alterations to ''Mir''{{'}}s orbit in preparation for the station's decommissioning. 20 November 1998 saw the launch of ''Zarya'', the first module of the [[Astronomy:International Space Station|ISS]], but delays to the new station's service module ''Zvezda'' had led to calls for ''Mir'' to be kept in orbit past 1999. Roscosmos confirmed that it would not fund ''Mir'' past the set deorbit date.<ref name="SSSM"/>

The crew of EO-27, Viktor Afanasyev and Jean-Pierre Haigneré, arrived in [[Engineering:Soyuz TM-29|Soyuz TM-29]] on 22 February 1999 alongside Ivan Bella, who returned to Earth with Padalka in Soyuz TM-28. The crew carried out three EVAs to retrieve experiments and deploy a prototype communications antenna on ''Sofora''. On 1 June it was announced that the deorbit of the station would be delayed by six months to allow time to seek alternative funding to keep the station operating. The rest of the expedition was spent preparing the station for its deorbit; a special analog computer was installed and each of the modules, starting with the docking module, was mothballed in turn and sealed off. The crew loaded their results into Soyuz TM-29 and departed ''Mir'' on 28 August 1999, ending a run of continuous occupation, which had lasted for eight days short of ten years.<ref name="SSSM"/> The station's [[Engineering:Control moment gyroscope|control moment gyroscope]]s (CMGs, or "gyrodynes") and main computer were shut down on 7 September, leaving [[Engineering:Progress M-42|Progress M-42]] to control ''Mir'' and refine the station's orbital decay rate.<ref name="SSSM"/>

Near the end of its life, there were plans for private interests to purchase ''Mir'', possibly for use as the first orbital [[Engineering:Television studio|television]]/movie studio{{Citation needed|date=March 2021|reason=no source provided}}. The privately funded [[Engineering:Soyuz TM-30|Soyuz TM-30]] mission by MirCorp, that was launched on 4 April 2000, carried two crew members, Sergei Zalyotin and Aleksandr Kaleri, to the station for two months to do repair work with the hope of proving that the station could be made safe. This was to be the last crewed mission to ''Mir''—while Russia was optimistic about ''Mir''{{'s}} future, its commitments to the ISS project left no funding to support the aging station.<ref name="SSSM"/><ref name="CNN">{{cite news|title=Mir Destroyed in Fiery Descent|publisher=CNN|url=http://archives.cnn.com/2001/TECH/space/03/23/mir.descent/index.html|access-date=10 November 2009|date=22 March 2001|url-status=dead|archive-url=https://web.archive.org/web/20091121134003/http://archives.cnn.com/2001/TECH/space/03/23/mir.descent/index.html|archive-date=21 November 2009}}</ref>

''Mir''{{'}}s deorbit was carried out in three stages. The first stage involved waiting for [[Physics:Drag|atmospheric drag]] to [[Astronomy:Orbital decay|reduce the station's orbit]] to an average of {{convert|220|km|mi}}. This began with the docking of [[Astronomy:Progress M1-5|Progress M1-5]], a modified version of the [[Engineering:Progress-M|Progress-M]] carrying 2.5 times more fuel in place of supplies. The second stage was the transfer of the station into a 165&nbsp;×&nbsp;220&nbsp;km (103&nbsp;×&nbsp;137&nbsp;mi) 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 100&nbsp;km/60&nbsp;mi 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 [[Earth:South Pacific Ocean|South Pacific Ocean]] around 06:00 UTC.<ref name="Reentry News">{{cite web|title=The Final Days of Mir |publisher=The Aerospace Corporation |url=http://www.reentrynews.com/Mir/sequence.html |access-date=16 April 2007 |url-status=dead |archive-url=https://web.archive.org/web/20090522131135/http://www.reentrynews.com/Mir/sequence.html |archive-date=22 May 2009 }}</ref><ref name="Reentry Page">{{cite web|title=Mir Space Station Reentry Page|publisher=Space Online|url=http://www.ik1sld.org/mirreentry_page.htm|access-date=16 April 2007|archive-url=https://web.archive.org/web/20070614034327/http://www.ik1sld.org/mirreentry_page.htm|archive-date=14 June 2007}}</ref>

===Visiting spacecraft===
{{Main|Engineering:Soyuz (spacecraft)|Engineering:Progress (spacecraft)|Engineering:Space Shuttle}}
[[File:Soyuz acoplada MIR.jpg|thumb|right|Soyuz TM-24 docked with ''Mir'' as seen from the {{OV|104}} 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 [[Engineering:Igla (spacecraft docking system)|Igla]] and Kurs systems, whilst the core module's forward port featured only the newer Kurs.<ref name="SSSM"/>

Soyuz spacecraft provided personnel access to and from the station allowing for crew rotations and cargo return, and also functioned as a lifeboat for the station, allowing for a relatively quick return to Earth in the event of an emergency.<ref name="SoyuzUS"/>{{page number|date=February 2021}}<ref name="Shuttle-Mir-Soyuz">{{cite web|title=Shuttle–Mir History/Spacecraft/Mir Space Station/Soyuz|publisher=NASA|date=4 March 2004|author=Kim Dismukes|url=http://spaceflight.nasa.gov/history/shuttle-mir/spacecraft/s-mir-soyuz.htm|access-date=11 February 2010|archive-date=15 February 2009|archive-url=https://web.archive.org/web/20090215015225/http://spaceflight.nasa.gov/history/shuttle-mir/spacecraft/s-mir-soyuz.htm|url-status=dead}}</ref> Two models of Soyuz flew to ''Mir''; [[Engineering:Soyuz T-15|Soyuz T-15]] was the only Igla-equipped [[Engineering:Soyuz-T|Soyuz-T]] to visit the station, whilst all other flights used the newer, Kurs-equipped [[Engineering:Soyuz-TM|Soyuz-TM]]. A total of 31 (30 crewed, [[Engineering:Soyuz TM-1|1 uncrewed]]) Soyuz spacecraft flew to the station over a fourteen-year period.<ref name="SoyuzUS"/>{{page number|date=February 2021}}

The uncrewed Progress cargo vehicles were only used to resupply the station, carrying a variety of cargoes including water, fuel, food and experimental equipment. The spacecraft were not equipped with reentry shielding and so, unlike their Soyuz counterparts, were incapable of surviving reentry.<ref name="Shuttle-Mir-Progress">{{cite web|title=Shuttle–Mir History/Spacecraft/Mir Space Station/Progress Detailed Description|publisher=NASA|date=4 March 2004|author=Kim Dismukes|url=http://spaceflight.nasa.gov/history/shuttle-mir/spacecraft/s-mir-detailed-main.htm|access-date=11 February 2010|archive-date=2 September 2009|archive-url=https://web.archive.org/web/20090902030958/http://spaceflight.nasa.gov/history/shuttle-mir/spacecraft/s-mir-detailed-main.htm|url-status=dead}}</ref> 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.<ref name="SoyuzUS"/>{{page number|date=February 2021}} In order to facilitate cargo return, ten Progress flights carried [[Astronomy:VBK-Raduga|''Raduga'']] capsules, which could return around 150&nbsp;kg of experimental results to Earth automatically.<ref name="SoyuzUS"/> ''Mir'' was visited by three separate models of Progress; the original [[Engineering:Progress 7K-TG|7K-TG]] variant equipped with Igla (18 flights), the [[Engineering:Progress-M|Progress-M]] model equipped with Kurs (43 flights), and the modified [[Engineering:Progress-M1|Progress-M1]] version (3 flights), which together flew a total of 64 resupply missions.<ref name="SoyuzUS"/> Whilst the Progress spacecraft usually docked automatically without incident, the station was equipped with a remote manual docking system, [[Astronomy:TORU|TORU]], in case problems were encountered during the automatic approaches. With TORU, cosmonauts could guide the spacecraft safely in to dock (with the exception of the catastrophic docking of [[Engineering:Progress M-34|Progress M-34]], when the long-range use of the system resulted in the spacecraft striking the station, damaging ''Spektr'' and causing [[Engineering:Uncontrolled decompression|decompression]]).<ref name="SSSM"/>{{rp|265}}

In addition to the routine Soyuz and Progress flights, it was anticipated that ''Mir'' would also be the destination for flights by the Soviet [[Engineering:Buran programme|''Buran'' space shuttle]], which was intended to deliver extra modules (based on the same "37K" [[Engineering:Satellite bus|bus]] as ''Kvant''-1) and provide a much improved cargo return service to the station. ''[[Astronomy:Kristall|Kristall]]'' carried two [[Astronomy:Androgynous Peripheral Attach System|Androgynous Peripheral Attach System]] (APAS-89) docking ports designed to be compatible with the shuttle. One port was to be used for ''Buran''; the other for the planned ''Pulsar'' X-2 telescope, also to be delivered by ''Buran''.<ref name="SSSM"/><ref name="russianspaceweb.com Kristall"/> The cancellation of the ''Buran'' programme meant these capabilities were not realised until the 1990s when the ports were used instead by US [[Engineering:Space Shuttle|Space Shuttle]]s as part of the Shuttle-''Mir'' programme (after testing by the specially modified [[Engineering:Soyuz TM-16|Soyuz TM-16]] in 1993). Initially, visiting [[Engineering:Space Shuttle orbiter|Space Shuttle orbiter]]s docked directly to ''Kristall'', but this required the relocation of the module to ensure sufficient distance between the shuttle and ''Mir''{{'}}s solar arrays.<ref name="SSSM"/> To eliminate the need to move the module and retract solar arrays for clearance issues, a [[Astronomy:Mir Docking Module|Mir Docking Module]] was later added to the end of ''Kristall''.<ref name="Encyclopedia Astronautica mirodule">{{cite web|title=Mir Docking Module|author=Mark Wade|publisher=Encyclopedia Astronautica|url=http://www.astronautix.com/craft/mirodule.htm|access-date=11 February 2010|url-status=dead|archive-url=https://web.archive.org/web/20100108043835/http://astronautix.com/craft/mirodule.htm|archive-date=8 January 2010}}</ref> 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 [[Engineering:Spacecraft|spacecraft]] in history at that time, with a combined mass of {{convert|250|t|short ton|lk=on}}.<ref name="SSSM"/>

===Mission control centre===
{{Main|Astronomy:RKA Mission Control Center}}
[[File:Russian Mission Control Center.jpg|thumb|[[Astronomy:RKA Mission Control Center|RKA Mission Control Center]] (2007)]]
''Mir'' and its resupply missions were controlled from the Russian [[Engineering:Mission control center|mission control centre]] ({{lang-ru|Центр управления полётами}}) in Korolyov, near the RKK Energia plant. Referred to by its acronym ЦУП ("TsUP"), or simply as 'Moscow', the facility could process data from up to ten spacecraft in three separate control rooms, although each control room was dedicated to a single programme; one to ''Mir''; one to ''Soyuz''; and one to the Soviet space shuttle ''Buran'' (which was later converted for use with the ISS).<ref name="TsUP">{{cite news|url=http://www.space.com/news/spacestation/missioncontrol_russia_000814.html|work=Space.com|access-date=13 July 2011|date=14 August 2000|author=Yuri Karash|title=Russia's Mission Control: Keeping ISS Aloft|archive-url=https://web.archive.org/web/20100207165302/http://www.space.com/news/spacestation/missioncontrol_russia_000814.html|archive-date=7 February 2010}}</ref><ref name="MCC-M">{{cite web|url=http://spaceflight.nasa.gov/history/shuttle-mir/history/to-h-b-operations-mcc.htm|access-date=6 November 2010|date=4 April 2004|publisher=NASA|title=Shuttle-Mir Background – Mission Control Center – Moscow|archive-date=16 October 2011|archive-url=https://web.archive.org/web/20111016215954/http://spaceflight.nasa.gov/history/shuttle-mir/history/to-h-b-operations-mcc.htm|url-status=dead}}</ref> The facility is now used to control the Russian Orbital Segment of the ISS.<ref name="TsUP"/> The flight control team were assigned roles similar to the system used by NASA at their mission control centre in Houston, including:<ref name="MCC-M"/>
* The Flight Director, who provided policy guidance and communicated with the mission management team;
* The Flight Shift Director, who was responsible for real-time decisions within a set of flight rules;
* The Mission Deputy Shift Manager (MDSM) for the MCC was responsible for the control room's consoles, computers and peripherals;
* The MDSM for Ground Control was responsible for communications;
* The MDSM for Crew Training was similar to NASA's 'capcom,' or capsule communicator; usually someone who had served as the ''Mir'' crew's lead trainer.

===Unused equipment===
Three command and control modules were constructed for the ''Mir'' program. One was used in space; one remained in a Moscow warehouse as a source of repair parts if needed,<ref>Air & Space/Smithsonian, October/November 1997, p. 17 'Mir Lands in Wisconsin"</ref> 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.<ref>{{Cite web|title=Russian Space Station MIR|url=https://www.tommybartlett.com/exploratory/exhibits/russian-space-station/|access-date=2023-02-14|website=Tommy Bartlett Exploratory|language=en-US}}</ref>

===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 [[Physics:Coolant|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.<ref name="OffPlanet"/>{{page number|date=February 2021}}

Various breakdowns of the Elektron oxygen-generating system were a concern; they led crews to become increasingly reliant on the backup [[Astronomy:Vika oxygen generator|''Vika'']] [[Chemistry:Chemical oxygen generator|solid-fuel oxygen generator]] (SFOG) systems, which led to a fire during the handover between EO-22 and EO-23.<ref name="SSSM"/><ref name="Dragonfly"/>{{page number|date=February 2021}} (see also [[Engineering:ISS ECLSS#Vika|ISS ECLSS]])

====Accidents====
[[File:Mir after Fire.jpg|thumb|A charred panel in ''Kvant''-1 following the ''Vika'' fire]]
Several accidents occurred which threatened the station's safety, such as the glancing collision between ''[[Astronomy:Kristall|Kristall]]'' and [[Engineering:Soyuz TM-17|Soyuz TM-17]] during proximity operations in January 1994. The three most alarming incidents occurred during [[Astronomy:Mir EO-23|EO-23]]. The first was on 23 February 1997 during the handover period from EO-22 to EO-23, when a malfunction occurred in the backup [[Astronomy:Vika oxygen generator|''Vika'']] system, a [[Chemistry:Chemical oxygen generator|chemical oxygen generator]] later known as solid-fuel oxygen generator (SFOG). The ''Vika'' malfunction led to a fire which burned for around 90 seconds (according to official sources at the TsUP; astronaut Jerry Linenger insists the fire burned for around 14 minutes), and produced large amounts of toxic smoke that filled the station for around 45 minutes. This forced the crew to don respirators, but some of the respirator masks initially worn were broken. Some of the [[Engineering:Fire extinguisher|fire extinguisher]]s mounted on the walls of the newer modules were immovable.<ref name="Dragonfly"/>{{page number|date=February 2021}}<ref name="OffPlanet"/>{{page number|date=February 2021}}
[[File:Mir collision damage STS086-720-091.JPG|thumb|Picture of the damage caused by the collision with Progress M-34. Picture was taken by Space Shuttle ''Atlantis'' during STS 86]]
The other two accidents concerned testing of the station's [[Astronomy:TORU|TORU]] manual docking system to manually dock [[Engineering:Progress M-33|Progress M-33]] and [[Engineering:Progress M-34|Progress M-34]]. The tests were to gauge the performance of long-distance docking and the feasibility of removal of the expensive ''Kurs'' automatic docking system from Progress spacecraft. Due to malfunctioning equipment, both tests failed, with Progress M-33 narrowly missing the station and Progress M-34 striking ''[[Astronomy:Spektr|Spektr]]'' and puncturing the module, causing the station to depressurise and leading to ''Spektr'' being permanently sealed off. This in turn led to a power crisis aboard ''Mir'' as the module's solar arrays produced a large proportion of the station's electrical supply, causing the station to power down and begin to drift, requiring weeks of work to rectify before work could continue as normal.<ref name="SSSM"/><ref name="Dragonfly"/>{{page number|date=February 2021}}

====Radiation and orbital debris====
[[File:Space Debris Low Earth Orbit.png|thumb|right|[[Astronomy:Space debris|Space debris]] in low Earth orbit]]
Without the protection of the Earth's atmosphere, cosmonauts were exposed to higher levels of [[Physics:Radiation|radiation]] from a steady flux of [[Astronomy:Cosmic ray|cosmic ray]]s and trapped protons from the [[Astronomy:South Atlantic Anomaly|South Atlantic Anomaly]]. The station's crews were exposed to an [[Physics:Absorbed dose|absorbed dose]] of about 5.2&nbsp;[[Physics:Gray (unit)|cGy]] over the course of the Mir EO-18 expedition, producing an [[Physics:Equivalent dose|equivalent dose]] of 14.75&nbsp;[[Physics:Sievert|cSv]], or 1133&nbsp;µSv per day.<ref>{{cite journal |title=Biodosimetry Results from Space Flight Mir-18 |journal=Radiation Research |year=1997 |volume=148 |issue=5 |pages=S17–S23 |doi=10.2307/3579712 |author=Yang TC |display-authors=0 |jstor=3579712|bibcode=1997RadR..148S..17Y}}</ref><ref>{{cite journal |doi=10.1016/S0273-1177(98)01070-9 |title=Radiation environment on the Mir orbital station during solar minimum |journal=[[Astronomy:Advances in Space Research|Advances in Space Research]] |year=1998 |volume=22 |issue=4 |pages=501–510 |author=Badhwar GD |pmid=11542778 |bibcode=1998AdSpR..22..501B 
|display-authors=1 |last2=Cash |last3=Petrov |last4=Akatov |last5=Tchernykh |last6=Shurshakov |last7=Arkhangelsky}}</ref> This daily dose is approximately that received from natural [[Physics:Background radiation|background radiation]] on Earth in two years.<ref>{{cite report|title=Report of the United Nations Scientific Committee on the Effects of Atomic Radiation to the General Assembly|date=26 July 2000|url=http://www.unscear.org/docs/reports/gareport.pdf|access-date=6 February 2011|archive-date=5 February 2009|archive-url=https://web.archive.org/web/20090205040744/http://www.unscear.org/docs/reports/gareport.pdf|url-status=live}}</ref> The radiation environment of the station was not uniform; closer proximity to the station's hull led to an increased radiation dose, and the strength of radiation shielding varied between modules; ''Kvant''-2's being better than the core module, for instance.<ref>{{cite journal|title=Measurement of the Depth Distribution of Average LET and Absorbed Dose Inside a Water – Filled Phantom on Board Space Station MIR|journal=Physica Medica|year=2001|volume=17|issue=Supplement 1|pages=128–130|pmid=11770528|url=http://www.ati.ac.at/~vanaweb/papers/Arona.pdf|access-date=6 February 2011|author=Berger T|display-authors=0 }}</ref>

The increased radiation levels pose a higher risk of crews developing cancer, and can cause damage to the [[Biology:Chromosome|chromosome]]s of [[Biology:Lymphocyte|lymphocyte]]s. These cells are central to the [[Biology:Immune system|immune system]] and so any damage to them could contribute to the lowered [[Medicine:Immunity (medical)|immunity]] experienced by cosmonauts. Over time, in theory, lowered immunity results in the spread of infection between crew members, especially in such confined areas. To avoid this only healthy people were permitted aboard. Radiation has also been linked to a higher incidence of [[Medicine:Cataract|cataract]]s in cosmonauts. Protective shielding and protective drugs may lower the risks to an acceptable level, but data is scarce and longer-term exposure will result in greater risks.<ref name="JCB"/>{{page number|date=February 2021}}

At the low altitudes at which ''Mir'' orbited there is a variety of [[Astronomy:Space debris|space debris]], consisting of everything from entire spent rocket stages and defunct [[Astronomy:Satellite|satellite]]s, to explosion fragments, paint flakes, slag from solid rocket motors,<ref>{{Cite web|title=Space Debris Basics {{!}} The Aerospace Corporation|url=http://www.aerospace.org/cords/space-debris-basics/|website=www.aerospace.org|access-date=28 November 2015|archive-url=https://web.archive.org/web/20151208141911/http://www.aerospace.org/cords/space-debris-basics/|archive-date=8 December 2015|url-status=dead}}</ref> coolant released by RORSAT nuclear powered satellites,<ref>{{Cite book|title=Space Debris: Models and Risk Analysis|url=https://archive.org/details/spacedebrismodel00klin_663|url-access=limited|last=Klinkrad|first=Heiner|publisher=Praxis Publishing Ltd.|year=2006|isbn=978-3540376743|page=[https://archive.org/details/spacedebrismodel00klin_663/page/n91 83]|bibcode=2006sdmr.book.....K}}</ref> [[Engineering:Project West Ford|small needles]], and many other objects. These objects, in addition to natural [[Astronomy:Micrometeoroid|micrometeoroid]]s,<ref>{{cite journal|author=F. L. Whipple|year=1949|title=The Theory of Micrometeoroids|journal=Popular Astronomy|volume=57|page=517|bibcode=1949PA.....57..517W}}</ref> 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.<ref>{{cite web|author=Henry Nahra|url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19890016664_1989016664.pdf|title=Effect of Micrometeoroid and Space Debris Impacts on the Space Station Freedom Solar Array Surfaces|date=24–29 April 1989|publisher=NASA|access-date=7 October 2009|archive-date=6 June 2011|archive-url=https://web.archive.org/web/20110606043107/http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19890016664_1989016664.pdf|url-status=live}}</ref> Micrometeoroids also posed a risk to spacewalking cosmonauts, as such objects could puncture their spacesuits, causing them to depressurise.<ref>{{cite news|url=http://www.space.com/missionlaunches/junk_iss_020107.html|title=Space Junk and ISS: A Threatening Problem|access-date=13 July 2011|work=Space.com|date=7 January 2002|author=Leonard David|archive-url=https://web.archive.org/web/20090523163656/http://www.space.com/missionlaunches/junk_iss_020107.html|archive-date=23 May 2009}}</ref> 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.<ref name="SSSM"/>
{{clear}}

==See also==
* [[Engineering:Skylab|Skylab]], a defunct predecessor space station
* ''[[Astronomy:Out of the Present|Out of the Present]]'', 1995 documentary
* ''[[Astronomy:Orphans of Apollo|Orphans of Apollo]]'', a 2008 documentary film which describes how a band of entrepreneurs tried to privatize the space station ''Mir'' and the resulting story of MirCorp.

==References==
{{Reflist}}

==External links==
* [https://history.nasa.gov/SP-4225/imagery/videos/mirdeorbit.mpg NASA animation of ''Mir'''s deorbit]
* [http://www.zarya.info/Diaries/StationsMir/Mir.php ''Mir'' Diary]
* [https://web.archive.org/web/20090601223325/http://www.russianspaceweb.com/mir.html Diagrams, pictures and background info]
* [http://www.jamesoberg.com/05181998mirmisinfo_mir.html Information on problems aboard Mir]
* [https://web.archive.org/web/20041117163319/http://spaceflight.nasa.gov/history/shuttle-mir/references/documents/phase1-joint-report.pdf Shuttle-''Mir'': Phase 1 Program Joint Report]
* [https://history.nasa.gov/SP-4225/mir/mir.htm Mir Space Station (NASA)]
{{S-start}}
{{s-bef|before=[[Engineering:Salyut 7|Salyut 7]]}}
{{s-ttl|title=''Mir''|years=1986–2001}}
{{s-aft|after=''Mir''-2 as the ROS in the [[Astronomy:International Space Station|ISS]]}}
{{S-end}}
{{Crewed spacecraft}}
{{Mir modules}}
{{Crewed Mir flights}}
{{Shuttle-Mir}}
{{Russian human spaceflight programs}}
{{Russian space program}}
{{US human spaceflight programs}}
{{Space stations}}
{{Spaceflight}}


[[Category:Mir| ]]
[[Category:Crewed spacecraft]]
[[Category:Crewed space program of Russia]]

{{Sourceattribution|Mir}}