Mir was the first continuously inhabited long-term research station in orbit and held the record for the longest continuoushuman presence in space at 3,644 days, until it was surpassed by the ISS on 23 October 2010.[13] It holds the record for the longest single human spaceflight, withValeri 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 theSalyut programme,Mir represented the next stage in the Soviet Union's space station programme. The first module of the station, known as thecore module or base block, was launched in 1986 and followed by six further modules.Protonrockets were used to launch all of its components except for thedocking module, which was installed by USSpace Shuttle missionSTS-74 in 1995. When complete, the station consisted of seven pressurised modules and several unpressurised components. Power was provided by severalphotovoltaic arrays attached directly to the modules. The station wasmaintained at an orbit between 296 km (184 mi) and 421 km (262 mi) altitude and travelled at an average speed of 27,700 km/h (17,200 mph), completing 15.7 orbits per day.[6][page needed][7][page needed][8]
The station was launched as part of the Soviet Union'screwed spaceflight programme effort to maintain a long-term research outpost in space, and following the collapse of the USSR, was operated by the newRussian Federal Space Agency (RKA). As a result, most of the station's occupants were Soviet; through international collaborations such as theInterkosmos,Euromir andShuttle–Mir programmes, the station was made accessible to space travellers from several Asian, European and North American nations.Mirwas deorbited in March 2001 after funding was cut off. The cost of theMir programme was estimated by former RKA General DirectorYuri Koptev in 2001 as $4.2 billion over its lifetime (including development, assembly and orbital operation).[14]
Mir was authorised by a 17 February 1976 decree, to design an improved model of theSalyut DOS-17K space stations. Four Salyut space stations had been launched since 1971, with three more being launched duringMir's development. It was planned that the station's core module (DOS-7 and the backupDOS-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.[15][failed verification][unreliable source?]
It was originally planned that the ports would connect to 7.5-tonne (8.3-short-ton) modules derived from theSoyuz spacecraft. These modules would have used a Soyuz propulsion module, as in Soyuz andProgress, and the descent and orbital modules would have been replaced with a long laboratory module.[15] Following a February 1979 governmental resolution, the programme was consolidated withVladimir Chelomei's crewedAlmaz military space station programme. The docking ports were reinforced to accommodate 20-tonne (22-short-ton) space station modules based on theTKS spacecraft.NPO Energia was responsible for the overall space station, with work subcontracted toKB Salyut, due to ongoing work on theEnergiarocket andSalyut 7,Soyuz-T, andProgress 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,Luch satellite communications system,Elektron oxygen generators, andVozdukhcarbon dioxide scrubbers.[15][failed verification][unreliable source?]
It was clear that the planned processing flow could not be followed and still meet the 1986 launch date. It was decided onCosmonaut's Day (12 April) 1985 to ship the flight model of thebase block to theBaikonur 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 atKhrunichev. In October, the base block was rolled outside itscleanroom 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.[15][failed verification][unreliable source?]
A diagram showing theKonus drogue and module movements aroundMir's docking node[16]
The orbital assembly ofMir began on 19 February 1986 with the launch of theProton-K rocket. Four of the six modules which were later added (Kvant-2 in 1989,Kristall in 1990,Spektr in 1995 andPriroda in 1996) followed the same sequence to be added to the mainMir 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 itsLyappa 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 twoKonus 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.[6][page needed][17][page needed]
The other two expansion modules,Kvant-1 in 1987 and thedocking 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 theTKS 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 aboardSpace ShuttleAtlantis duringSTS-74 and mated to the orbiter'sOrbiter Docking System.Atlantis then docked, via the module, toKristall, then left the module behind when it undocked later in the mission.[17]: 248–249 [18] 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.[17][page needed]
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 inspace architecture). First generation stations such asSalyut 1 andSkylab had monolithic designs, consisting of one module with no resupply capability; the second generation stationsSalyut 6 andSalyut 7 comprised a monolithic station with two ports to allow consumables to be replenished by cargo spacecraft such asProgress. The capability ofMir 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.[17][page needed]
In its completed configuration, the space station consisted of seven different modules, each launched into orbit separately over a period of ten years by eitherProton-K rockets orSpace ShuttleAtlantis.
The base block for the entireMir complex, the core module, or DOS-7, provided the main living quarters for resident crews and contained environmental systems, early attitude control systems and the station's main engines. The module was based on hardware developed as part of theSalyut 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 forKvant-1.[19][page needed]
The first expansion module to be launched,Kvant-1 consisted of two pressurised working compartments and one unpressurised experiment compartment. Scientific equipment included anX-ray telescope, anultraviolet 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 sixgyrodynes for attitude control, in addition to life support systems including anElektron oxygen generator and aVozdukh carbon dioxide scrubber.[19][page needed]
The firstTKS based module,Kvant-2, was divided into three compartments: anEVA 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 theManned Maneuvering Unit for theOrlan space suit, referred to asIkar, a system for regenerating water from urine, a shower, theRodnik water storage system and sixgyrodynes to augment those already located inKvant-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 raisingquail.[19][page needed]
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 twoAPAS-89docking ports initially intended for use with theBuran programme and eventually used during theShuttle-Mir programme. The docking compartment also contained the Priroda 5 camera used for Earth resources experiments.Kristall also carried sixcontrol moment gyroscopes (CMGs, or "gyrodynes") for attitude control to augment those already on the station, and two collapsible solar arrays.[19][page needed]
Spektr was the first of the three modules launched during the Shuttle-Mir programme; it served as the living quarters for American astronauts and housedNASA-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 withProgress M-34 in 1997 which damaged the module, exposing it to the vacuum of space.[17][page needed]
The docking module was designed to help simplifySpace Shuttledockings toMir. Before the first shuttle docking mission (STS-71), theKristall module had to be tediously moved to ensure sufficient clearance betweenAtlantis andMir's solar arrays. With the addition of the docking module, enough clearance was provided without the need to relocateKristall. It had two identicalAPAS-89 docking ports, one attached to the distal port ofKristall with the other available for shuttle docking.[17]: 247–249
The seventh and finalMir 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 mountedsynthetic aperture radar dish.[17]: 251–253
The Travers radar antenna,Sofora girder, VDU thruster block, SPK unit and aStrela crane, alongsideKvant-2 andPriroda
In addition to the pressurised modules,Mir featured several external components. The largest component was theSofora girder, a large scaffolding-like structure consisting of 20 segments which, when assembled, projected 14 metres from its mount onKvant-1. A self-contained thruster block, the VDU (Vynosnaya Dvigatyelnaya Ustanovka), was mounted on the end ofSofora and was used to augment the roll-control thrusters on the core module. The VDU's increased distance fromMir's axis allowed an 85% decrease in fuel consumption, reducing the amount of propellant required to orient the station.[17][page needed] A second girder,Rapana, was mounted aft ofSofora onKvant-1. This girder, a small prototype of a structure intended to be used onMir-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.[17][page needed]
To assist in moving objects around the exterior of the station duringEVAs,Mir featured twoStrela 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 1.8 metres (6 ft) when collapsed, but when extended using a hand crank were 14 metres (46 ft) long, meaning that all of the station's modules could be accessed during spacewalks.[20]
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 toPriroda. Thissynthetic 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 onPriroda, including various radiometers and scan platforms.[19][page needed]Kvant-2 also featured several scan platforms and was fitted with a mounting bracket to which thecosmonaut manoeuvring unit, orIkar, was mated. This backpack was designed to assist cosmonauts in moving around the station and the plannedBuran in a manner similar to the USManned Maneuvering Unit, but it was only used once, duringEO-5.[17][page needed]
In addition to module-specific equipment,Kvant-2,Kristall,Spektr andPriroda were each equipped with oneLyappa 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.[19][page needed]
Photovoltaic (PV) arrays poweredMir. The station used a 28 voltDC supply which provided 5-, 10-, 20- and 50-amp taps. When the station was illuminated by sunlight, several solar arrays mounted on the pressurised modules provided power toMir's systems and charged thenickel-cadmium storage batteries installed throughout the station.[17] The arrays rotated in only one degree of freedom over a 180° arc, and tracked the Sun usingSun sensors 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 thatMir 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 Ah capacity, were then used to power the station until the arrays recovered their maximum output on the day side of Earth.[17]
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 m2 (409 ft2) in area, were launched on the core module, and together provided a total of 9 kW of power. A third,dorsal panel was launched onKvant-1 and mounted on the core module in 1987, providing a further 2 kW from a 22 m2 (237 ft2) area.[17]Kvant-2, launched in 1989, provided two 10 m (32.8 ft) long panels which supplied 3.5 kW each, whilstKristall was launched with two collapsible, 15 m (49.2 ft) long arrays (providing 4 kW each) which were intended to be moved toKvant-1 and installed on mounts which were attached during a spacewalk by theEO-8 crew in 1991.[17][19]
This relocation was begun in 1995, when the panels were retracted and the left panel installed onKvant-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 m2 (1360 ft2) of array with a 16 kW supply.[17] Two further arrays were flown to the station on board theSpace ShuttleAtlantis duringSTS-74, carried on the docking module. The first of these, theMir cooperative solar array, consisted of American photovoltaic cells mounted on a Russian frame. It was installed on the unoccupied mount onKvant-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 kW.[17] The other panel, originally intended to be launched onPriroda, replaced theKristall panel onKvant-1 in November 1997, completing the station's electrical system.[17]
Graph showing the changing altitude ofMir from 19 February 1986 until 21 March 2001
Mir was maintained in a near circular orbit with an average perigee of 354 km (220 mi) and an average apogee of 374 km (232 mi), travelling at an average speed of 27,700 km/h (17,200 mph) and completing 15.7 orbits per day.[6][7][8] As the station constantly lost altitude because of slightatmospheric 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 ofKvant-1, the engines on the core module could also accomplish the task.[17]
Attitude control was maintained by a combination of two mechanisms; in order to hold a set attitude, a system of twelvecontrol moment gyroscopes (CMGs, or "gyrodynes") rotating at 10,000 rpm kept the station oriented, six CMGs being located in each of theKvant-1 andKvant-2 modules.[19][21] When the attitude 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 theSofora girder) were used to attain the new attitude and the CMGs were reengaged.[21] 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.[17] Conversely, materials processing experiments required the minimisation of movement on board the station, and soMir would be oriented in agravity gradient attitude for stability.[17] Prior to the arrival of the modules containing these gyrodynes, the station's attitude 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.[17][22][page needed]
Radio communications providedtelemetry and scientific data links betweenMir and theRKA Mission Control Centre (TsUP). Radio links were also used duringrendezvous 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 theLiraantenna mounted to thecore module. TheLira antenna also had the capability to use theLuch data relay satellite system (which fell into disrepair in the 1990s) and the network of Soviettracking ships deployed in various locations around the world (which also became unavailable in the 1990s).[17]UHF radio was used by cosmonauts conductingEVAs. 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 andMir crew members via theTORU system.[17]
AtMir'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 ofweightlessness, the onboard environment was not one of weightlessness or zero gravity. The environment was often described asmicrogravity. This state of perceived weightlessness was not perfect, being disturbed by five separate effects:[23]
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 rpm, producing vibrations of 166.67 Hz[21]) or thrusters;
Tidal forces. Any parts ofMir not at exactly the same distance from Earth tended tofollow 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.
Mir'senvironmental control and life support system (ECLSS) provided or controlledatmospheric 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. TheElektron system generated oxygenelectrolytically, venting hydrogen to space. Bottled oxygen andsolid fuel oxygen generation (SFOG) canisters, a system known asVika, provided backup. Carbon dioxide was removed from the air by theVozdukh system.[17] Other byproducts of human metabolism, such as methane from the intestines and ammonia from sweat, were removed byactivated charcoal filters. Similar systems are presently used on the ISS.
The atmosphere onMir was similar toEarth's.[24] Normal air pressure on the station was 101.3 kPa (14.7 psi); the same as at sea level on Earth.[17] An Earth-like atmosphere offers benefits for crew comfort.[25]
Reinhold Ewald (right) andVasily Tsibliyev in thecore module during Ewald's visit toMirScale model replica of the MIR Space Station at the Euro Space Center Belgium
Interkosmos (Russian: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 toMir but none resulted in an extended stay in the station:
In the early 1980s, NASA planned to launch a modular space station calledFreedom as a counterpart toMir, while the Soviets were planning to constructMir-2 in the 1990s as a replacement for the station.[17][page needed] Because of budget and design constraints,Freedom never progressed past mock-ups and minor component tests and, withthe fall of the Soviet Union and the end of theSpace Race, the project was nearly cancelled entirely by theUnited States House of Representatives. Thepost-Soviet economic chaos in Russia also led to the cancellation ofMir-2, though only after its base block,DOS-8, had been constructed.[17] 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.[17] In June 1992, American presidentGeorge H. W. Bush and Russian presidentBoris Yeltsin agreed to cooperate onspace exploration. The resultingAgreement 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 Americanastronaut deployed to the Russian space stationMir and two Russiancosmonauts deployed to a Space Shuttle.[17]
In September 1993, US Vice PresidentAl Gore Jr., and Russian Prime MinisterViktor Chernomyrdin announced plans for a new space station, which eventually became theISS.[33] They also agreed, in preparation for this new project, that the United States would be heavily involved in theMir programme as part of an international project known as theShuttle–Mir Programme.[34] 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 theirspace agencies, the USNational Aeronautics and Space Administration (NASA) and theRussian 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.
Time exposure ofMir passing over Earth's surface, May 1997.A video tour ofMir from September 1996, duringSTS-79A view of the interior of thecore module's docking node, showing the crowded nature of the station.
Inside, the 130-tonne (140-short-ton)Mir resembled a crampedlabyrinth, 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.[38] As a result, NASA astronaut John Blaha reported that, with the exception ofPriroda andSpektr, 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.[39]
The time zone used on boardMir wasMoscow Time (MSK;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 MSK, 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.[17]
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 aboardMir), or make use of the station's ham radio.[17] Two amateur radio call signs, U1MIR and U2MIR, were assigned toMir in the late1980s, allowingamateur radio operators on Earth to communicate with the cosmonauts.[40] The station was also equipped with a supply ofbooks andfilms for the crew to read and watch.[22]
NASA astronaut Jerry Linenger related how life on boardMir 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 onMir, 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 onMir 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.[41][page needed]
AstronautShannon Lucid, who set the record for longest stay in space by a woman while aboardMir (surpassed bySunita Williams 11 years later on the ISS), also commented about working aboardMir: "I think going to work on a daily basis onMir 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."[39]
Shannon Lucid exercises on a treadmill during her stay aboardMir.
The most significant adverse effects of long-term weightlessness aremuscle atrophy and deterioration of theskeleton, orspaceflight osteopenia. Other significant effects include fluid redistribution, a slowing of thecardiovascular system, decreased production ofred blood cells, balance disorders, and a weakening of theimmune system. Lesser symptoms include loss of body mass, nasal congestion, sleep disturbance, excessflatulence, and puffiness of the face. These effects begin to reverse quickly upon return to the Earth.[42][page needed]
To prevent some of these effects, the station was equipped with twotreadmills (in the core module andKvant-2) and astationary bicycle (in the core module); each cosmonaut was to cycle the equivalent of 10 kilometres (6.2 mi) and run the equivalent of 5 kilometres (3.1 mi) per day.[17] 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.[43]
There were twospace toilets (ASUs) onMir, located in thecore module andKvant-2.[22] 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 theElektron system.[17]
Mir featured a shower, theBania, located inKvant-2. It was an improvement on the units installed in previousSalyut 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.[17]
On a 1998 visit toMir, bacteria and larger organisms were found to have proliferated in water globules formed from moisture that had condensed behind service panels.[44]
The station provided two permanent crew quarters, theKayutkas, 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 withinSpektr until a collision with aProgress spacecraft caused the depressurisation of that module.[17] 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.[45]
Most of the food eaten by station crews was frozen, refrigerated or canned. Meals were prepared by the cosmonauts, with the help of adietitian, before their flight to the station. The diet was designed to provide around 100 g ofprotein, 130 g offat and 330 g ofcarbohydrates per day, in addition to appropriate mineral and vitamin supplements. Meals were spaced out through the day to aid assimilation.[17] 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 ofcognac andvodka for special occasions.[22]
In the 1990s ninety species of micro-organisms were found insideMir, 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.[46] Molds that develop aboard space stations can produce acids that degrade metal, glass and rubber.[47] The molds inMir 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.[48] Researchers in 2018 reported, after detecting the presence on theInternational Space Station (ISS) of fiveEnterobacter bugandensis bacterial strains, none pathogenic to humans, thatmicroorganisms on ISS should be carefully monitored to continue ensuring a medically healthy environment for the astronauts.[49][50]
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.[48] On the other hand, some scientists are conducting research on whether this situation can be used for life in space. Scientists have discovered that fungi could actually assist space travel and detect livable environments for humankind in space. In fact, these resilient and frequently underestimated organisms might hold the key to our future on other planets. Fungi play a dramatic role in creating innovative and sustainable building materials. Most fungi possessmycelia, hair-like root structures that grow and spread across surfaces. As mycelia expand, they bind surrounding materials, as wood chips, sawdust, orregolith (the loose material covering solid rock on planetary bodies like the Moon or Mars). This growth process results in a dense, interconnected network that creates a remarkably strong and durable substance. The resulting mycelium-based material offers notablethermal insulation and radiation protection, making it an ideal candidate for construction, particularly in severe environments like outer space or other interplanetary habitats.[51]
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 ofEO-28 to the 437-day flight ofValeri Polyakov), but generally lasted around six months.[17] 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).[17] 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.[17][52][page needed] The station was occupied for a total of four distinct periods; 12 March–16 July 1986 (EO-1), 5 February 1987 – 27 April 1989 (EO-2–EO-4), the record-breaking run from 5 September 1989 – 28 August 1999 (EO-5–EO-27), and 4 April–16 June 2000 (EO-28).[52][page needed] By the end, it had beenvisited by 104 different people from twelve different nations, making it the most visited spacecraft in history (a record latersurpassed by the ISS).[17]
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 launchSoyuz T-15 on a dual mission to bothMir andSalyut 7.[15][unreliable source?]
On 5 May 1986, they undocked fromMir for a day-long journey to Salyut 7. They spent 51 days there and gathered 400 kg of scientific material from Salyut 7 for return toMir. While Soyuz T-15 was at Salyut 7, the uncrewedSoyuz TM-1 arrived at the unoccupiedMir and remained for 9 days, testing the newSoyuz TM model. Soyuz T-15 redocked withMir on 26 June and delivered the experiments and 20 instruments, including a multichannelspectrometer. The EO-1 crew spent their last 20 days onMir conducting Earth observations before returning to Earth on 16 July 1986, leaving the new station unoccupied.[54][unreliable source?]
The second expedition toMir,EO-2, launched onSoyuz TM-2 on 5 February 1987. During their stay, theKvant-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 toMir onBuran.Kvant-1 was originally planned to dock withSalyut 7; due to technical problems during its development, it was reassigned toMir. The module carried the first set of six gyroscopes for attitude control. The module also carried instruments for X-ray and ultraviolet astrophysical observations.[19]
The initial rendezvous of theKvant-1 module withMir 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,Yuri Romanenko andAleksandr Laveykin, conducted anEVA 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.[55][unreliable source?][56]
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) andJean-Loup Chrétien (France). With the departure ofEO-4 onSoyuz TM-7 on 27 April 1989 the station was again left unoccupied.[17]
The launch ofSoyuz 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.[13] It also marked the beginning ofMir's second expansion. TheKvant-2 andKristall modules were now ready for launch.Alexander Viktorenko andAleksandr Serebrov docked withMir 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 ofKvant-2, the first of the 20 tonne add-on modules based on theTKS spacecraft from theAlmaz programme.[57][unreliable source?]
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 bothKvant-2 andMir, the new module was docked manually on 6 December.Kvant-2 added a second set ofcontrol moment gyroscopes (CMGs, or "gyrodynes") toMir, 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 asIkar), an equivalent of the USManned Maneuvering Unit, was located insideKvant-2's airlock.[57][58]
Soyuz TM-9 launchedEO-6 crew membersAnatoly Solovyev andAleksandr 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 boardMir saw the addition of theKristall module, launched 31 May 1990. The first docking attempt on 6 June was aborted due to an attitude control thruster failure.Kristall arrived at the front port on 10 June and was relocated to the lateral port oppositeKvant-2 the next day, restoring the equilibrium of the complex. Due to the delay in the docking ofKristall, 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.[59][unreliable source?]
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 twoAndrogynous Peripheral Attach System (APAS-89) docking ports designed to be compatible with theBuran spacecraft. Although they were never used in aBuran docking, they were useful later during the Shuttle-Mir programme, providing a berthing location for USSpace Shuttles.[60]
TheEO-7 relief crew arrived aboardSoyuz TM-10 on 3 August 1990. The new crew arrived atMir withquail forKvant-2's cages, one of which laid an egg en route to the station. It was returned to Earth, along with 130 kg of experiment results and industrial products, in Soyuz TM-9.[59] Two more expeditions,EO-8 andEO-9, continued the work of their predecessors whilst tensions grew back on Earth.
The first human mission flown from an independentKazakhstan wasSoyuz TM-14, launched on 17 March 1992, which carried theEO-11 crew toMir, docking on 19 March before the departure of Soyuz TM-13. On 17 June, Russian PresidentBoris Yeltsin and US PresidentGeorge 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 ofSpektr andPriroda).EO-12 followed in July, alongside a brief visit by French astronautMichel Tognini.[52][page needed] The following crew,EO-13, began preparations for the Shuttle-Mir programme by flying to the station in a modified spacecraft,Soyuz TM-16 (launched on 26 January 1993), which was equipped with anAPAS-89 docking system rather than the usual probe-and-drogue, enabling it to dock toKristall 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 calledRezonans conducted on 28 January.Soyuz TM-15, meanwhile, departed with the EO-12 crew on 1 February.[52][page needed]
Throughout the period following the collapse of the USSR, crews onMir experienced occasional reminders of theeconomic chaos occurring in Russia. The initial cancellation ofSpektr andPriroda was the first such sign, followed by the reduction in communications as a result of the fleet oftracking ships being withdrawn from service byUkraine. The new Ukrainian government also vastly raised the price of theKurs docking systems, manufactured inKyiv – the Russians' attempts to reduce their dependence onKurs 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 theEO-14 crew aboardSoyuz TM-17 in July; shortly before launch there was a black-out at the pad, and the power supply to the nearby city ofLeninsk failed an hour after launch.[17][52][page needed] Nevertheless, the spacecraft launched on time and arrived at the station two days later. All ofMir'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 whileProgress M-18 vacated the core module's front port and departed.[52][page needed]
The EO-13 crew departed on 22 July, and soon afterMir passed through the annualPerseidmeteor 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.Soyuz TM-18 arrived on 10 January 1994 carrying theEO-15 crew (includingValeri Polyakov, who was to remain onMir for 14 months), andSoyuz TM-17 left on 14 January. The undocking was unusual in that the spacecraft was to pass alongKristall 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 ofKristall.[52][page needed]
The launch ofSoyuz TM-19, carrying theEO-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 theEO-17 crew arrived inSoyuz TM-20.[52][page needed]
On 3 February 1995, the launch ofSpace ShuttleDiscovery, flyingSTS-63, opened operations onMir. Referred to as the "near-Mir" mission, the mission saw the first rendezvous of a Space Shuttle withMir as the orbiter approached within 37 feet (11 m) of the station as a dress rehearsal for later docking missions and for equipment testing.[65][66][67] Five weeks afterDiscovery's departure, theEO-18 crew, including the first US cosmonautNorman Thagard, arrived inSoyuz TM-21. The EO-17 crew left a few days later, with Polyakov completing his record-breaking 437-day spaceflight. During EO-18, theSpektr science module (which served as living and working space for American astronauts) was launched aboard aProton rocket and docked to the station, carrying research equipment from America and other nations. The expedition's crew returned to Earth aboardSpace ShuttleAtlantis following the first Shuttle–Mir docking mission,STS-71.[17][22][page needed]Atlantis, launched on 27 June 1995, successfully docked withMir on 29 June becoming the first US spacecraft to dock with a Russian spacecraft since theASTP in 1975.[68] The orbiter delivered theEO-19 crew and returned the EO-18 crew to Earth.[65][69][70] TheEO-20 crew were launched on 3 September, followed in November by the arrival of the docking module duringSTS-74.[18][65][71][72]
On 21 February 1996, the two-manEO-21 crew was launched aboardSoyuz TM-23, and they were soon joined by US crew memberShannon Lucid, who was brought to the station byAtlantis duringSTS-76. During this mission, the first joint US spacewalk onMir took place, deploying theMir Environmental Effects Payload package for the docking module.[73] Lucid became the first American to carry out a long-duration mission aboardMir with her 188-day mission, which set the US single spaceflight record. During Lucid's time aboardMir,Priroda, the station's final module, arrived as did French visitorClaudie Haigneré flying theCassiopée mission. The flight aboardSoyuz TM-24 also delivered theEO-22 crew ofValery Korzun andAleksandr Kaleri.[17][65][74]
On 16 September 1996, with the launch ofAtlantis and theSTS-79 flight, Lucid's stay aboardMir ended. During this fourth docking,John Blaha transferred ontoMir to take his place as resident US astronaut. His stay on the station improved operations in a number of areas, including transfer procedures for a docked space shuttle, "hand-over" procedures for long-duration American crew members, and "ham"amateur radio communications, as well as two spacewalks to reconfigure the station's power grid. Blaha spent four months with the EO-22 crew before returning to Earth aboardAtlantis onSTS-81 in January 1997, at which point he was replaced byphysicianJerry Linenger.[65][75][76] During his flight, Linenger became the first American to conduct a spacewalk from a foreign space station and the first to test the Russian-builtOrlan-M spacesuit alongside Russian cosmonautVasili Tsibliyev, flyingEO-23. All three crew members of EO-23 performed a "fly-around" inSoyuz TM-25 spacecraft.[17] Linenger and his Russian crewmates Vasili Tsibliyev andAleksandr Lazutkin faced several difficulties during the mission, including the most severe fire aboard an orbiting spacecraft (caused by a malfunctioningVika), failures of various systems, a near collision withProgress M-33 during a long-distance TORU test and a total loss of station electrical power. The power failure also caused a loss ofattitude control, which led to an uncontrolled "tumble" through space.[17][22][page needed][41][page needed][65]
Damaged solar arrays on theMirSpektr module following a collision withProgress M-34 in September 1997.
Linenger was succeeded byAnglo-American astronautMichael Foale, carried up byAtlantis onSTS-84, alongside Russian mission specialistElena Kondakova. Foale's increment proceeded fairly normally until 25 June when during the second test of theProgress manual docking system,TORU,Progress M-34 collided with solar arrays on theSpektr 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 closingSpektr's hatch, prevented the crews having to abandon the station inSoyuz TM-25. Their efforts stabilised the station's air pressure, whilst the pressure inSpektr, containing many of Foale's experiments and personal effects, dropped to a vacuum.[22][page needed][65] In an effort to restore some of the power and systems lost following the isolation ofSpektr and to attempt to locate the leak,EO-24 commanderAnatoly Solovyev andflight engineerPavel 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 fromSpektr's systems to the rest of the station. Following these first investigations, Foale and Solovyev conducted a 6-hour EVA outsideSpektr to inspect the damage.[65][77]
After these incidents, the US Congress and NASA considered whether to abandon the programme out of concern for the astronauts' safety, but NASA administratorDaniel Goldin decided to continue.[41][page needed] The next flight toMir,STS-86, carriedDavid Wolf aboardAtlantis. 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 inSpektr's hull.[65][78] Wolf spent 119 days aboardMir with the EO-24 crew and was replaced duringSTS-89 withAndy Thomas, who carried out the last US expedition onMir.[65][79] TheEO-25 crew arrived inSoyuz TM-27 in January 1998 before Thomas returned to Earth on the final Shuttle–Mir mission,STS-91.[65][80][81]
Mir breaks up in Earth's atmosphere over theSouth Pacific on 23 March 2001.
Following the 8 June 1998 departure ofDiscovery, the EO-25 crew ofBudarin andMusabayev remained onMir, completing materials experiments and compiling a station inventory. On 2 July,Roskosmos director Yuri Koptev announced that, due to a lack of funding to keepMir active, the station would be deorbited in June 1999.[17] TheEO-26 crew ofGennady Padalka andSergei Avdeyev arrived on 15 August inSoyuz TM-28, alongside physicistYuri Baturin, who departed with the EO-25 crew on 25 August inSoyuz TM-27. The crew carried out two spacewalks, one insideSpektr to reseat some power cables and another outside to set up experiments delivered byProgress M-40, which also carried a large amount of propellant to begin alterations toMir's orbit in preparation for the station's decommissioning. 20 November 1998 saw the launch ofZarya, the first module of theISS, but delays to the new station's service moduleZvezda had led to calls forMir to be kept in orbit past 1999. Roscosmos confirmed that it would not fundMir past the set deorbit date.[17]
The crew ofEO-27,Viktor Afanasyev andJean-Pierre Haigneré, arrived inSoyuz TM-29 on 22 February 1999 alongsideIvan 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 onSofora. 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 departedMir on 28 August 1999, ending a run of continuous occupation, which had lasted for eight days short of ten years.[17] The station'scontrol moment gyroscopes (CMGs, or "gyrodynes") and main computer were shut down on 7 September, leavingProgress M-42 to controlMir and refine the station's orbital decay rate.[17]
Near the end of its life, there were plans for private interests to purchaseMir, possibly for use as the first orbitaltelevision/movie studio.[citation needed] The privately fundedSoyuz TM-30 mission by MirCorp, that was launched on 4 April 2000, carried two crew members,Sergei Zalyotin andAleksandr 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 toMir—while Russia was optimistic aboutMir's future, its commitments to the ISS project left no funding to support the aging station.[17][82]
Mir's deorbit was carried out in three stages. The first stage involved waiting foratmospheric drag toreduce the station's orbit to an average of 220 kilometres (140 mi). This began with the docking ofProgress M1-5, a modified version of theProgress-M carrying 2.5 times more fuel in place of supplies. The second stage was the transfer of the station into a 165 × 220 km (103 × 137 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 km/60 mi AMSL) occurred at 05:44 UTC nearNadi,Fiji. Major destruction of the station began around 05:52 UTC and most of the unburned fragments fell into theSouth Pacific Ocean around 06:00 UTC.[83][84]
Mir was primarily supported by the RussianSoyuz andProgress 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 ofKvant-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 onMir; the rear ports of both the core module andKvant-1 were equipped with both theIgla andKurs systems, whilst the core module's forward port featured only the newer Kurs.[17]
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.[52][page needed][85] Two models of Soyuz flew toMir;Soyuz T-15 was the only Igla-equippedSoyuz-T to visit the station, whilst all other flights used the newer, Kurs-equippedSoyuz-TM. A total of 31 (30 crewed,1 uncrewed) Soyuz spacecraft flew to the station over a fourteen-year period.[52][page needed]
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.[86] 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.[52][page needed] In order to facilitate cargo return, ten Progress flights carriedRaduga capsules, which could return around 150 kg of experimental results to Earth automatically.[52]Mir was visited by three separate models of Progress; the original7K-TG variant equipped with Igla (18 flights), theProgress-M model equipped with Kurs (43 flights), and the modifiedProgress-M1 version (3 flights), which together flew a total of 64 resupply missions.[52] Whilst the Progress spacecraft usually docked automatically without incident, the station was equipped with a remote manual docking system,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 ofProgress M-34, when the long-range use of the system resulted in the spacecraft striking the station, damagingSpektr and causingdecompression).[17]: 265
In addition to the routine Soyuz and Progress flights, it was anticipated thatMir would also be the destination for flights by the SovietBuran space shuttle, which was intended to deliver extra modules (based on the same "37K"bus asKvant-1) and provide a much improved cargo return service to the station.Kristall carried twoAndrogynous Peripheral Attach System (APAS-89) docking ports designed to be compatible with the shuttle. One port was to be used forBuran; the other for the plannedPulsar X-2 telescope, also to be delivered byBuran.[17][60] The cancellation of theBuran programme meant these capabilities were not realised until the 1990s when the ports were used instead by USSpace Shuttles as part of the Shuttle-Mir programme (after testing by the specially modifiedSoyuz TM-16 in 1993). Initially, visitingSpace Shuttle orbiters docked directly toKristall, but this required the relocation of the module to ensure sufficient distance between the shuttle andMir's solar arrays.[17] To eliminate the need to move the module and retract solar arrays for clearance issues, aMir Docking Module was later added to the end ofKristall.[87] 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 toMir, the temporary enlargements of living and working areas amounted to a complex that was the largestspacecraft in history at that time, with a combined mass of 250tonnes (280short tons).[17]
Mir and its resupply missions were controlled from the Russianmission control centre (Russian:Центр управления полётами) inKorolyov, near theRKK 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 toMir; one toSoyuz; and one to the Soviet space shuttleBuran (which was later converted for use with the ISS).[88][89] The facility is now used to control theRussian Orbital Segment of the ISS.[88] The flight control team were assigned roles similar to the system used by NASA at their mission control centre inHouston, including:[89]
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 theMir crew's lead trainer.
Three command and control modules were constructed for theMir program. One was used in space; one remained in a Moscow warehouse as a source of repair parts if needed,[90] 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 toWisconsin Dells, Wisconsin, where it became the centrepiece of the complex's Space Exploration wing.[91]
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 ofcoolant. 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 insideMir, he was shocked by the intensity of the smell and worried about the possible negative health effects of breathing such contaminated air.[41][page needed]
Various breakdowns of the Elektron oxygen-generating system were a concern; they led crews to become increasingly reliant on the backupVikasolid-fuel oxygen generator (SFOG) systems, which led to a fire during the handover between EO-22 and EO-23.[17][22][page needed] (see alsoISS ECLSS)
Several accidents occurred which threatened the station's safety, such as the glancing collision betweenKristall andSoyuz TM-17 during proximity operations in January 1994. The three most alarming incidents occurred duringEO-23. The first was on 23 February 1997 during the handover period fromEO-22 to EO-23, when a malfunction occurred in the backupVika system, achemical oxygen generator later known as solid-fuel oxygen generator (SFOG). TheVika malfunction led to a fire which burned for around 90 seconds (according to official sources at the TsUP; astronautJerry 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 thefire extinguishers mounted on the walls of the newer modules were immovable.[22][page needed][41][page needed]
The other two accidents concerned testing of the station'sTORU manual docking system to manually dockProgress M-33 andProgress M-34. The tests were to gauge the performance of long-distance docking and the feasibility of removal of the expensiveKurs 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 strikingSpektr and puncturing the module, causing the station to depressurise and leading toSpektr being permanently sealed off. This in turn led to a power crisis aboardMir 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.[17][22][page needed]
Without the protection of the Earth's atmosphere, cosmonauts were exposed to higher levels ofradiation from a steady flux ofcosmic rays and trapped protons from theSouth Atlantic Anomaly. The station's crews were exposed to anabsorbed dose of about 5.2 cGy over the course of theMir EO-18 expedition, producing anequivalent dose of 14.75 cSv, or 1133 μSv per day.[92][93] This daily dose is approximately that received from naturalbackground radiation on Earth in two years.[94] 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.[95]
The increased radiation levels pose a higher risk of crews developing cancer, and can cause damage to thechromosomes oflymphocytes. These cells are central to theimmune system and so any damage to them could contribute to the loweredimmunity 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 ofcataracts 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.[42][page needed]
At the low altitudes at whichMir orbited there is a variety ofspace debris, consisting of everything from entire spentrocket stages and defunctsatellites, to explosion fragments, paint flakes, slag from solid rocket motors,[96] coolant released byRORSAT nuclear powered satellites,[97]small needles, and many other objects. These objects, in addition to naturalmicrometeoroids,[98] 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.[99] Micrometeoroids also posed a risk tospacewalking cosmonauts, as such objects couldpuncture their spacesuits, causing them to depressurise.[100] Meteor showers in particular posed a risk, and, during such storms, the crews slept in their Soyuz ferries to facilitate an emergency evacuation shouldMir be damaged.[17]
Orphans of Apollo, a 2008 documentary film which describes how a band of entrepreneurs tried to privatize the space stationMir and the resulting story of MirCorp.
^Craig Freudenrich (20 November 2000)."How Space Stations Work". Howstuffworks.Archived from the original on 12 December 2008. Retrieved23 November 2008.
^"Biography of Chris Hadfield".Canadian Space Agency. Government of Canada. 22 July 2014.Archived from the original on 9 June 2020. Retrieved8 May 2020.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.
^Sawyer, Kathy (29 January 1995). "US & Russia Find Common Ground in Space – Nations Overcome Hurdles in Ambitious Partnership".The Washington Post.NewsBank. p. a1.
^Scott, David; Leonov, Alexei (30 April 2005).Two Sides of the Moon. Pocket Books.ISBN978-0-7434-5067-6.
^Harwood, William (15 November 1995). "Space Shuttle docks with Mir – Atlantis uses manoeuvres similar to those needed for construction".The Washington Post. NewsBank. p. a3.
^Harwood, William (28 March 1996). "Shuttle becomes hard-hat area; spacewalking astronauts practice tasks necessary to build station".The Washington Post. NewsBank. p. a3.
^Hoffman, David (22 August 1997). "Crucial Mir spacewalk carries high hopes – continued Western support could hinge on mission's success".The Washington Post. pp. a1.
Launches are separated by dots ( • ), payloads by commas ( , ), multiple names for the same satellite by slashes ( / ). Crewed flights are underlined. Launch failures are marked with the † sign. Payloads deployed from other spacecraft are (enclosed in parentheses).
