Mir

Mir (; lit. Peace, World or Society) was a Soviet and later Russian space station, operational in low Earth orbit from 1986 to 2001. With a greater mass than that of any previous space station, Mir was the first of the third generation type of space station, constructed from 1986 to 1996 with a modular design, and was the largest artificial satellite orbiting the Earth until its deorbit on 21 March 2001, a record now surpassed by the International Space Station (ISS). Mir served as a microgravity research laboratory in which crews conducted experiments in biology, human biology, physics, astronomy, meteorology and spacecraft systems, with an aim to develop technologies required for the permanent occupation of space. The station was the first consistently inhabited long-term research station in space, and was operated by a series of long-duration crews. The Mir programme currently holds the record for the longest uninterrupted human presence in space, at 9 years and 257 days, and for the longest single human spaceflight, of Valeri Polyakov, at 437 days 18 hours. Mir was occupied for a total of twelve and a half years of its fifteen-year lifespan, having the capacity to support a resident crew of three and larger crews for short-term visits.

Following the success of the Salyut programme, Mir represented the next stage in the Soviet Union's space station programme. The first module of the station, known as the core module or base block, was launched in 1986, and was followed by six further modules, all being launched by Proton rockets (with the exception of the docking module). When complete, the station consisted of seven pressurised modules and several unpressurised components. Power was provided by several solar arrays mounted directly to the modules. The station was maintained at an orbit between and altitude and travelled at an average speed of 27,700 km/h (17,200 mph), completing 15.7 orbits per day.

The station was originally launched as part of the Soviet Union's manned spaceflight programme's 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, the vast majority of the station's crew were Soviet or Russian, however, through a number of international collaborations, including Intercosmos, Euromir and the Shuttle-Mir Program, the station was made accessible to astronauts from North America, several western European nations and Japan, as well as cosmonauts from various eastern nations. The cost of the station was estimated by Yuri Koptev in 2001 as $4.3 billion over the lifetime of the station, including its development, assembly and orbital operation, making Mir the eleventh most expensive object ever constructed. The station was serviced by Soyuz spacecraft, Progress spacecraft and (during the Shuttle-Mir programme) US space shuttles, and was visited by astronauts and cosmonauts from 12 different nations. |- | rowspan="2" | Kvant-1
(Astrophysics Module) | TM-2 | 31 March 1987 | Proton-K | Soviet Union | rowspan="2" | | rowspan="2" | |- style="border-bottom: 3px solid gray" | colspan="4" | The first expansion module to be launched, Kvant-1 consisted of two pressurized working compartments and one unpressurised experiment compartment. Scientific equipment included an X-ray telescope, an 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 gyrodines for attitude control, life support systems including an Elektron oxygen generator and Vozdukh carbon dioxide scrubber.

Each module was also fitted with a number of external components specific to the experiments that were carried out within that module, the most obvious of which was the Travers antenna mounted to Priroda. This synthetic aperture radar consisted of a large dish-like framework mounted to the exterior of the module, with associated equipment within, and was used for Earth observations experiments, as was most of the other equipment on Priroda, including various radiometers and scan platforms. 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 the Sofora girder) used to establish the new attitude, and the CMGs reengaged.

* The drag resulting from the residual atmosphere.

Vibratory acceleration caused by mechanical systems and the crew on board the station.

Orbital corrections by the on-board gyroscopes (which span at 10,000 rpm, producing vibrations of 166.67 Hz 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 Space Race, Freedom was nearly cancelled 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. They also agreed, in preparation for this new project, that the United States would be heavily involved in the Mir program as part of an international project known as the Shuttle–Mir program. The project, sometimes called "Phase One", was intended to allow the United States to learn from Russian experience with long-duration spaceflight and to foster a spirit of cooperation between the two nations and their space agencies, the US National Aeronautics and Space Administration (NASA) and the Russian Federal Space Agency (Roskosmos). The project helped to prepare the way for further cooperative space ventures; specifically, "Phase Two" of the joint project, the construction of the International Space Station (ISS). The program 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 American astronauts occurred over the course of seven long-duration expeditions.

==Life on board== wears a respirator following a fire aboard Mir.]] Inside, the 100-ton Mir looked like 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 it sometimes supported as many as six for up to a month. Except for two short periods, Mir was continuously occupied until August 1999.

Air aboard the station has been described as 'very healthy, - it's not dry, it's not humid. Nothing smells.' by NASA astronaut John Blaha. He also describes that with the exception of the Priroda and Spektr which were added very recently, the station does look used, which is to be expected given it has been lived in for 10 to 11 years without being brought home and cleaned.

Blaha's account of the air quality aboard Mir contradicts sharply the concerns about air quality on the space station that Jerry Linenger relates in his book about his time on the facility. Linenger says that due to the age of the space station, the cooling system on board had developed a plethora of tiny leaks too small and numerous to be repaired, that permitted the constant release of coolant into the air on board making it unpleasant to breathe. He says that it was especially noticeable after he had made a space walk and become used to the clean air he had been breathing in his space suit. When he returned to the station and began breathing the air inside Mir again, he was deeply shocked by the intensity of the chemical smell and very worried about the possible negative health effects of breathing such heavily contaminated air.

Peter Rodney Llewellyn almost visited Mir in 1999 after promising US$100 million for the privilege.

Station operations

Expeditions

Early existence

Due to the pressure to launch the station in such short order, mission planners were left without Soyuz spacecraft or modules to launch to the station at first. It was decided to launch Soyuz T-15 on a dual mission to both Mir and Salyut 7.

Leonid Kizim and Vladimir Solovyov first docked with the Mir space station on March 15, 1986. During their nearly 51-day stay on Mir, they brought the station online and checked its systems. They also unloaded two Progress spacecraft launched after their arrival, Progress-25 and Progress-26.

with Kvant-1 and Soyuz TM-3.]] On May 5, 1986 they undocked from Mir for a day-long journey to Salyut 7. They spent 51 days there and gathered 400 kg of scientific material from Salyut 7 for return to Mir. While Soyuz T-15 was at Salyut 7, the unmanned Soyuz TM-1 arrived at the unoccupied Mir and remained for 9 days, testing the new Soyuz TM. Soyuz T-15 redocked with Mir on June 26 and delivered the experiments and 20 instruments, including a multichannel spectrometer. The EO-1 crew spent their last 20 days on Mir conducting Earth observations before returning to earth on July 16, 1986, leaving the new station unoccupied.

The second expedition to Mir, Mir EO-2, launched on Soyuz TM-2 on February 5, 1987. During their stay, the Kvant-1 module was launched on March 30, 1987. It was the first, experimental version of a planned series of '37K' modules scheduled to be launched to Mir on the Soviet Buran space shuttle. Kvant-1 was originally planned to dock with Salyut 7; however, due to technical problems during its development, it was reassigned for Mir. The module carried the first set of six gyroscopes for attitude control. The module also carried instruments for X-ray and ultraviolet astrophysical observation.

The Soyuz TM-2 launch was the beginning of a string of 6 Soyuz launches and three long-duration crews between February 5, 1987 and April 27, 1989. This time period also saw the first international visitors to the station, Muhammed Faris, Abdul Ahad Mohmand and Jean-Loup Chrétien. With the departure of Mir EO-4 on Soyuz TM-7 April 27, 1989 the station was once again left unoccupied.

Second start

The launch of Soyuz TM-8 on September 5, 1989 marked the beginning of the longest human presence in space to date. It also marked the beginning of Mir's second expansion. The Kvant-2 and Kristall modules were now ready for launch. Alexander Viktorenko and Aleksandr Serebrov docked with Mir and brought the station out of its five-month hibernation. On September 29 the cosmonauts installed equipment in the docking system in preparation for the arrival of Kvant 2, the first of the 20-ton add-on modules based on the TKS spacecraft from the Almaz program

in 1989.]] After a delay of 40 days due to problems with a batch of computer chips, Kvant-2 was launched on November 26. After problems deploying the craft's solar array and with the automated docking systems on both Kvant-2 and Mir, Kvant-2 was docked manually on December 6. Kvant-2 added a second set of gyrodines to Mir. The module also carried the new life support systems for recycling water and generating oxygen on board Mir, reducing its dependence on resupply from the ground. Kvant-2 also featured a large airlock with a one-meter hatch. A special backpack unit, an equivalent of the U.S. Manned Maneuvering Unit, was located inside Kvant-2's airlock.

in 1990]] Soyuz TM-9 launched Mir EO-6 crew members Anatoly Solovyev and Aleksandr Balandin on February 11, 1990. While docking, the EO-5 crew on board Mir saw that 3 thermal blankets on the Soyuz-TM 9 were loose, potentially creating problems on reentry. It was decided that this would be manageable. Their stay on board Mir saw the addition of the Kristall module. The module was launched on May 31. The first docking attempt on June 6 was aborted due to an attitude control thruster failure. The Kristall module arrived at Mir’s front port on June 10, 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 Kristall’s systems, and to accommodate the EVA to repair the loose thermal blankets on Soyuz-TM 9.

The Kristall module contained a number of furnaces for the creation of crystals in micro-gravity. Also on board was biotechnology research equipment, including a small greenhouse for plant cultivation experiments. The unit was equipped with a source of light and a feeding system. The module also contained equipment for astronomy observations. The main feature, however, was the two APAS-89 Androgynous Peripheral Attach System docking ports designed to be compatible with the Buran shuttle. Although they were never used with a Buran Shuttle, they were later used with the American Space Shuttle.

The EO-7 relief crew arrived aboard Soyuz TM-10 on August 3, 1990. The new crew arrived at Mir with quail for Kvant-2's cages. A quail 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.

Shuttle–Mir

.]]

The US involvement in Mir brought new funds to the station. The most notable use of these was the completion and launch of the Spektr & Priroda modules and the construction of a docking module to make the process of docking the shuttle to the station easier.

Linenger was succeeded by Anglo-American astronaut Michael Foale, carried up by Atlantis on STS-84, alongside Russian mission specialist Elena Kondakova. in September 1997.]]

Foale's increment proceeded fairly normally until June 25, when during the second test of the Progress manual docking system, TORU, the resupply ship collided with solar arrays on the Spektr module and crashed into the module's outer shell, holing the module and causing a depressurisation of the station, the first ever on-orbit depressurisation in the history of spaceflight. Only quick actions on the part of the crew, cutting cables leading to the module and closing Spektr's hatch, prevented the crew abandoning the station in their Soyuz lifeboat. 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. Fortunately, food, water and other vital supplies were stored in other modules, and remarkable salvage and replanning effort by Foale and the science community maximized the scientific return.

Final days and deorbit

Near the end of its life, there were plans for private interests to purchase Mir, possibly for use as the first orbital television/movie studio. The privately-funded Soyuz TM-30 mission by MirCorp, launched on April 4, 2000, carried two crew members, Sergei Zalyotin and Alexandr Kaleri, to the station for two months to do repair work with the hope of proving that the station could be made safe. But this was to be the last manned mission to Mir. While Russia was optimistic about Mir's future, its commitments to the International Space Station project left no funding to support the aging Mir.

Mir's deorbit was done in three stages. The first stage was waiting for atmospheric drag to decay Mir’s orbit an average of . This began with the docking of Progress M1-5, a modified version of the Progress M carrying 2.5 times more fuel in place of supplies. The second stage was the transfer of the station into a 165 × 220 km (103 × 137 mi) orbit. This was achieved with two burns of the Progress M1-5's control engines at 00:32 UTC and 02:01 UTC on March 23, 2001. After a two-orbit pause, the third and final stage of Mir's deorbit began with the burn of Progress M1-5's control engines and main engine at 05:08 UTC, lasting a little over 22 minutes. Reentry into Earth's atmosphere (100 km/60 mi) of the 15-year-old space station occurred at 05:44 UTC near Nadi, Fiji. Major destruction of the station began around 05:52 UTC and the unburned fragments fell into the South Pacific Ocean around 06:00 UTC.

Visiting spacecraft

docked with Mir as seen from ]] Mir was primarily supported by the Russian Soyuz and Progress spacecraft. Soyuz craft provided manned access to and from the station, allowing for crew rotations, and also functioned as a lifeboat for the station, allowing for a relatively quick return to earth in the event of an emergency. The unmanned Progress cargo vehicles were only used to resupply the station and were incapable of surviving reentry.

It was anticipated that it would also be the destination for flights by the later-abandoned Buran space shuttle. The Kristall module even carried two APAS-89 Androgynous Peripheral Attach System docking ports designed to be compatible with the Buran shuttle. These were later used with the American Space Shuttle. The shuttles provided crew rotation of the American astronauts on station as well as carrying cargo to and from the station, performing some of the largest transfers of cargo of the time. With a space shuttle docked to Mir the temporary enlargements of living and working areas amounted to a complex that was the largest spacecraft in history at that time, with a combined mass of .

Mission control centre

Safety aspects

Ageing systems and accidents

In the later years of the programme, particularly during the Shuttle-Mir programme, Mir suffered from various systems failures as the station aged. The station was originally designed to fly for five years but eventually flew for three times that length of time, and in the 1990s was showing its age—constant computer crashes, loss of power, uncontrolled tumbles through space and leaking pipes were an ever-present concern for crews. Various breakdowns of Mir's Elektron oxygen-generating system were also a concern. These breakdowns led crews to become increasingly reliant on the backup Vika solid-fuel oxygen generator (SFOG) systems, responsible for the fire during the handover between EO-22 and EO-23.

The Vika malfunction led to a fire which burned for, according to various sources, between 90 seconds and 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. Fire extinguishers mounted on the walls of the modules were immovable. A similar incident had occurred on an earlier expedition, although in that case the Vika burned for only a few seconds. Now used aboard the ISS, the Vikas continue to be a problem.

The near-miss and collision incidents during EO-23 presented further safety issues. Both were caused by failure of the same piece of equipment, the TORU manual docking system, which was undergoing tests at the time. The tests were called in order to gauge the performance of long-distance docking in order to enable the cash-strapped Russians to remove the expensive Kurs automatic docking system from Progress spacecraft.

References

External links

* NASA animation of Mir's deorbit.

Mir Diary

Site containing detailed diagrams, pictures and background info

Site contains information on problems aboard Mir

Shuttle-Mir: Phase 1 Program Joint Report

Soviet Space Stations as Analogs - NASA report

Category:Mir Category:Space stations Category:Manned spacecraft Category:Deorbited spacecraft