Mir Space Station

Mir Space Station

The space station Mir became a legend in its own time reflecting RussiaÆs past space glories and her future as a leader in space.

The Russian Space Station Mir endured 15 years in orbit, three times its planned lifetime. It outlasted the Soviet Union, that launched it into space. It hosted scores of crewmembers and international visitors. It raised the first crop of wheat to be grown from seed to seed in outer space. It was the scene of joyous reunions, feats of courage, moments of panic, and months of grim determination. It suffered dangerous fires, a nearly catastrophic collision, and darkened periods of out-of-control tumbling.

Mir soared as a symbol of RussiaÆs past space glories and her potential future as a leader in space. And it served as the stageùhistoryÆs highest stageùfor the first large-scale, technical partnership between Russia and the United States after a half-century of mutual antagonism.

Mir did all of that and like most legends was controversial and paradoxical. At different times and by different people, Mir was called both "venerable" and "derelict." It was also "robust," "accident-prone," and "a marvel," as well as "a lemon."

For Russians, the very name "Mir" held meaning, feeling, and history. Mir translates into English as "world," "peace," and "village," but a single-word translation misses its full significance. Historically, after the Edict of Emancipation in 1861, the word "mir" referred to a Russian peasant community that owned its own land. A system of state-owned collective farms replaced the mir after the Russian revolution of 1917.

Read an essay by Frank Culbertson, Shuttle-Mir Program Manager, on the meanings of "Mir: WhatÆs in a Name?"

As with most legends, Mir was literally beyond the reach of most men and women, but it could be seen by many as a bright light arcing across the night sky. Mir undoubtedly provoked many thoughts around the globe about who weùas a human raceùare and where we are going.

The cosmonauts and astronauts who were fortunate enough to travel to Mir were always impressed by its appearance. Regardless, Mir remained difficult to describe. Someone once called Mir a 100-ton Tinker Toy, a term that recalled MirÆs construction. Adding modules over the years, and then sometimes rearranging them, the Russians had built the strangest, biggest structure ever seen in outer space. Traveling at an average speed of 17,885 mph, the space station orbited about 250 miles above the Earth. Mir was both great and gracefulùand incongruous and awkwardùall at the same time.

In outward appearance, Mir has also been compared to a dragonfly with its wings outstretched, and to a hedgehog whose spines could pierce a spacewalkerÆs suit. NASA-4 Mir Astronaut Jerry Linenger compared Mir to "six school buses all hooked together. It was as if four of the buses were driven into a four-way intersection at the same time. They collided and became attached. All at right angles to each other, these four buses made up the four Mir science modules. à Priroda and Spektr were relatively new additions à and looked itùeach sporting shiny gold foil, bleached-white solar blankets, and unmarred thruster pods. Kvant-2 and Kristall à showed their age. Solar blankets were yellowed à and looked as drab as a Moscow winter and were pockmarked with raggedy holes, the result of losing battles with micrometeorite and debris strikes over the years."

On the inside, Mir often surprised people, too, even when they thought they were ready for the view. By the time Americans arrived on Mirùnearly a decade into its lifeùthe station had become cluttered with used-up and broken equipment and floating bags of trash. During MirÆs lifetime, no adequate remedy was ever developed to deal with the stowage situation. Mir looked like a metal rabbit warren, or, as Mike Foale put it, "a bit like a frat house, but more organized and better looked after."

Still, Mir was home and shelter to its crews, and how it looked to them depended on their perspectives and situations. The ivory-like controls of the Base Block reminded David Wolf of classic science-fiction stories, such as The Time Machine, by H.G. Wells. After a fly-around in the cramped Soyuz capsule, Jerry Linenger wrote: "Looking into the station I could see a lone ray of light shining through the port widow and outlining the dining table. We had left some food out for dinner. It was the only time during my stay in space that Mir looked warm, inviting, and spacious. It reminded me of opening the door to a summer cottage that been boarded up for the winter, looking inside, and seeing familiar surroundings."

Mir set every record in long-duration spaceflight. Physician Valeri Polyakov lived aboard Mir for a single, continuous-orbit stay of 437 days, 17 hours and 38 minutes. He completed his stay in 1995 as American Norm Thagard began his Mir residency. Polyakov's experiences contributed greatly to the biomedical studies of long-term human spaceflight conducted by the Institute of Biomedical Problems, where he served as Deputy Director. Combined with an earlier Mir expedition flight, the Russian cosmonaut spent a total 678 days, 16 hours and 33 minutes on the Russian space station. However, his achievement for total time in space was surpassed in 1999 by Sergei Avdeyev who endured a total 747 days, 14 hours and 12 minutes, during three space missions. During Shuttle-Mir, Shannon Lucid set the space endurance record for women in 1996 when she spent 188 days, 4 hours and 00 minutes in orbit.

Just as "mir"ùthe wordùhad many meanings for Russians, Mirùthe placeùprovoked many different feelings. In February 1995, Russian cosmonaut Vladimir Titov flew aboard the "near Mir" flight, STS-63, when the Shuttle rendezvoused with Mir. Six years earlier, Titov had spent a year aboard Mir as an expedition member, when Mir consisted of only the Base Block, the two Kvant modules, a Soyuz, and a Progress spacecraft. About seeing Mir again, Titov said, "It was very wonderful, a wonderful view." STS-63 did not dock, but Titov visited Mir again as a crewmember of STS-86.

Alas, the sturdy Mir was built on a sinking foundation. Without repeated boostings, all things in low Earth orbit must eventually come down. With the new International Space Station requiring much of the Russian space programÆs attention and financing, the Mir Space Station was doomed to be deorbited. A strong effort rallied in Russia to keep Mir aloft; and at one point, Russian State Duma representatives were calling for the firing of Yuri Koptev from his post as the head of RussiaÆs aerospace agency. However, on December 30, 2000, Russian Prime Minister Mikhail Kasyanov signed a resolution calling for Mir to be sunk into the ocean, early in 2001.

Concerns circled the globe about Mir crashing into populated areas. MirÆs path crossed over nearly every city on Earth. Its orbits tracked over everything between 51 degrees North and South latitude, roughly within the limits of the Aleutian Islands to the north and the southern Andes Mountains to the south. Pieces of previous large spacecraft had landed in Canada, Australia, and southern South America, albeit fortunately without any damages or casualties.

For Mir, Russia acquired insurance in the event that its deorbit caused some physical damage. Japan kept a close watch because the final orbit would bring the Mir over the island nation. The U.S. government provided Russia with tracking and trajectory data, atmospheric conditions, and even solar activity, which can cause the EarthÆs atmosphere to expand farther into space. Although there was considerable certainty that debris could be limited to falling in the ocean, Yuri Semenov, RSC Energia President, was quoted as saying, "We donÆt have a 100-percent safety guarantee."

After more than 86,000 total orbits, Mir re-entered EarthÆs atmosphere on Friday, March 23, 2001, at 9 a.m. Moscow time. The 134-ton space structure broke up over the southern Pacific Ocean. Some of its larger pieces blazed harmlessly into the sea, about 1,800 miles east of New Zealand. Observers in Fiji reported spectacular gold- and white-streaming lights. An amazing saga and a highly successful program finally had come to a watery end.

Anatoly Solovyev had lived a total of 651 days on Mir and served as Mir-24 commander for Americans Mike Foale and David Wolf. He was quoted in Star City as saying, "I am especially sad these days. An entire era of our Soviet space program is ending, into which we invested not only our money but, what is more important, our intellectual potential."

The RussiansÆ investment began when a Soviet Proton launcher boosted MirÆs Base Block (core module) into orbit on February 20, 1986. This module resembled the existing Salyut-7 space station, but MirÆs design called for expansion through the addition of future modules. MirÆs first crew arrived in mid-March 1986, and the inaugural crew of Leonid Kizim and Vladimir Solovyev stayed aboard until May 5, 1986. This Solovyev would later become the Russian cochair of the Flight Operations Working Group for the Shuttle-Mir Program. And it was he who took charge of the Moscow Mission Control Center immediately after the Progress resupply vehicle collided with Mir, during NASA-5 Mir Astronaut Mike FoaleÆs residency.

In 1987, the Soviets added MirÆs first expansion module, Kvant-1, and had the worldÆs first modular space station. They still needed a more versatile way of transporting crews and equipment to and from Mirùsomething like the American Space Shuttle. In 1988, the Soviets launched the Buran, a winged, reusable space vehicle and a close copy of the U.S. Shuttle. Its first flight was near perfect. However, at this point in history, the Soviet Union was crumbling. No further Buran flights were attempted; four planned orbiters remained unfinished.

The Soyuz-TM vehicle and Progress-M resupply (cargo) vehicle became the transports of crews and supplies to the Mir. The Kvant-1 featured a docking port to accommodate the arrival of these spacecraft. The system worked well as the Russian space station was unoccupied on only five brief occasions until its deorbit on March 23, 2001. During its existence, the station had remained almost continuously occupied for nine years.

Mir continued to expand during the next years with the additions of modules for research and residence. Kvant-2 arrived in November 1989 with an airlock that allowed crewmembers access to the outside of the complex for extravehicular activities. Kristall, launched at the end of May 1990, housed Earth observation instruments and was used for semiconductor and biological experiments. Five years later, Spektr, a remote-sensing module for geophysical sciences, was added to the Mir.

On June 29, 1995, U.S. Space Shuttles began docking with the Russian space station. Before this first docking, the Mir-19 crew used the Lyappa manipulator arm to relocate the Kristall, thus allowing ample clearance for Atlantis. In November 1995, a new docking module arrived via STS-74 and was attached to the Kristall to provide means for future dockings without interference. The next year, on April 23, 1996, the final module, the Priroda, was added to the Mir.

The complex retained a docked Soyuz-TM vehicle at all times as this spacecraft served as the crewÆs "lifeboat." The vehicle carried a maximum of three persons, took two to three days to reach its destination, and could remain docked with the Mir for approximately 200 days before its orbital lifetime limit expired.

The resident Soyuz was used for an occasional, scheduled "fly-around" of the T-shaped Mir, but crews primarily ventured outside for extravehicular activities (EVAs). During MirÆs lifetime, crewmembers spent more than 325 hours as part of 75 planned spacewalks to conduct research and repairs on the exterior of the structure. Additional hours were spent during three intravehicular walks inside the unpressurized Spektr module. Participants in the Mir EVAs included 29 Russian cosmonauts, 3 U.S. astronauts, 2 French astronauts, and 1 European Space Agency astronaut who was a citizen of Germany. Cosmonaut Anatoly Solovyev donned the Russian Orlan spacesuit for 16 spacewalks for a total time of 77 hours, 46 minutesùmore EVA time than any other spacewalker in the world.

After the Russian space station moved into its second decade, the Mir became notorious as an accident-prone spacecraft, even as it remained unparalleled in continuous service. A 15-minute fire in an oxygen-generating device imperiled the station in February 1997. Failures of the Elektron electrolysis oxygen-enerating units and problems with attitude and environmental controls often seemed to alternate with computer malfunctions and power outages. The June 1997 collision with the Progress supply vehicle breached the integrity of the SpektrÆs hull and rendered that module uninhabitable.

But, Mir remained; and its space explorers endured. Over its lifetime, the space station hosted 125 cosmonauts and astronauts from 12 different nations. It supported 17 space expeditions, including 28 long-term crews.

Its residents arrived via the 31 spacecraft that docked with Mir; nine of the dockings involved the Space Shuttle. Additionally, 64 uncrewed cargo vessels ferried supplies and equipment periodically to Mir. And, it served as a floating laboratory for 23,000 scientific and medical experiments.

Although Mir was gone by early 2001 and the International Space Station (ISS) was growing rapidly in orbit, the U.S. and Russia were still using spacecraft as statecraft. On March 23ùthe same day as MirÆs deorbitùRussia expelled four U.S. diplomats and said it would expel 46 more, in retaliation for the American expulsion of 50 Russian diplomats for espionage-like activities. It wasnÆt the Cold War, all over again, but international tensions were certainly continuing, and the need remained for a worthy program for U.S. and Russian cooperation.

One could still apply to the ISS the same hopes that Shuttle Commander Charlie Precourt had held for it during Shuttle-Mir. Precourt had predicted that the ISS would "provide the psychological impetus for politicians to force themselves to find an agreement to disputes that otherwise they wouldnÆtùbecause theyÆll all look up there and say, æWell, we have an investment in that, too. We have to keep this relationship going in a proper direction.Æ" Although the U.S.-Russian relationship was still going in the "proper direction," toward continued cooperation in space, the proper use and the funding of ISS were still in question. NASA cost overruns for the ISS clouded the programÆs future, and RussiaÆs foreign department was threatening to reduce its participation in the ISS. To make the situation even more complicated, the ISS partner nations were discussing whether Russia should launch a wealthy, American "space tourist" to the space station.

Notwithstanding all the diplomatic wrangling, MirÆs demise also coincided neatly with the successful finish to the first U.S.-Russian expedition to the ISS. On March 22, 2001, Expedition One crewmembers Sergei Krikalev, Yuri Gidzenko, and Commander William Shepherd returned to the Johnson Space Center in Houston. They received a ride from STS-102 Shuttle Commander James Wetherbee and a crew that included former Mir resident Andy Thomas. STS-102 had ferried the Expedition Two crew of James Voss, Susan Helms, and Commander Yury Usachev to the station.

Just as the ISS itself grew out of the lessons of Mir, many of the principal people in the ISS Program drew from their experiences during the Shuttle-Mir Program. And, in Houston and in Moscow, American and Russian managers, engineers and technicians who had worked in the Shuttle-Mir Program were working to make the ISS a success.

The International Space Station was growing, but the memories of Mir refused to fade. Indeed, people had anticipated its demise for long enough that, even before it fell, it had entered nostalgia. In a 1998 interview, Vladimir Semyachkin reflected on Mir. He had developed the motion control systems and navigation systems for all vehicles and stations that were produced and launched into space by RSC Energia. Semyachkin, as much as anyone, had wrestled with MirÆs problems. He said:

"ItÆs a shameà. Our child, who we gave birth to so many years ago, à weÆre going to have to put it to sleep. But, on the other hand, we understand that sometimes thereÆs nothing to be doneà. One cannot sit, as it were, on two chairs at the same time. Nevertheless, despite this sorrow with à regard to Mir, we nonetheless do look forward to the future with a great deal of hope."

See Diagrams of the Mir Space Station

Go on a video tour of Mir with Shannon Lucid

See animation video of the Mir Space Station deorbit and reentry

Back to
Mir
TOC

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Mir Base Block

The Mir Base Block (core module) evolved from the earlier Soviet Salyut to serve as the heart of the space station. Launched in February 1986, the 13.1-meter-long, 20.4-metric ton core contained the primary living and working area, and life support and power, as well as the main computer, communications, and control equipmentùall in 90 cubic meters of habitable volume. MirÆs environment was generally maintained at temperatures of 64░F to 82░F and humidity of 20 to 70 percent. The core had four main compartments.

The Working Compartment was actually two cylinders connected by a conical section. It provided operations and living areas. Operations included monitoring, command, and scientific activities. The living area provided the necessities for long-duration missions, including a galley with a table, cooking elements, trash storage; a bicycle exerciser and treadmill with medical monitoring equipment; video equipment; and individual crew areas, each with a porthole, hinged chair, and sleeping bag. The personal hygiene area, with toilet and sink, was located in one end of the working compartment. Mir had several portholes, with shutters outside to protect them from orbital debris impacts. Two television screens permitted face-to-face communications with the ground. Four more television screens monitored the other Mir modules.

The Transfer Compartment was a spherical structure at the front end of Mir, providing one end-docking port for visiting spacecraft, plus four radial berthing ports, set in a 90-degree arrangement, for access to the stationÆs added modules. An approaching module used the Kurs (course) automatic docking system to dock with the forward port. Crews could then use the moduleÆs manipulator arm system to move it to a radial port, thus freeing the forward port for future use. The Transfer Compartment had no simulated "up and down" indicators; it was an area of Mir where astronauts reported sensations of disorientation.

The nonpressurized Assembly Compartment, on the other end of the Base Block, contained the stationÆs main engine and fuel tanks; it supported antennas, lights, and optical sensors. The pressurized Intermediate Compartment tunneled through the Assembly Compartment to connect the Working Compartment to the aft docking port, where the Kvant-1 module was permanently docked.

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Kvant I

Kvant means "quantum." When Kvant-1 was docked permanently to MirÆs aft docking port in April 1987, it increased MirÆs usable volume and expanded its scientific capabilities. Kvant-1 supported research in the physics of galaxies, quasars, and neutron stars by measuring electromagnetic emissions. The module also supported biotechnology experiments and had some station control and life support functions. The 11-metric ton Kvant-1 measured 4.4 meters by 6.3 meters long, with 40 cubic meters of pressurized volume. The module was equipped with six gyrodynes that provided accurate pointing of the station and significantly reduced the amount of fuel used for attitude control. Its aft docking port was available for Soyuz and Progress vehicles.

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Kvant II

Kvant-2 was a scientific and airlock module, providing biological research, Earth observations, and extravehicular activity capabilities.

The Kvant-2 enhanced Mir with drinking water and oxygen provisions, motion control systems, and power distribution, as well as shower and washing facilities. Its airlock contained a self-sustained cosmonaut maneuvering unit that increased the range and complexity of extravehicular activity tasks. The 19.6-metric ton Kvant-2 measured 4.4 meters by 13.7 meters long with 61.3 cubic meters of volume and 27.4 meters of solar arrays. It was the first module equipped with the Lyappa manipulator arm, used to move the modules after they docked with Mir. The Kvant-2 docked with Mir in November 1989.

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Kristall

Kristall means "crystal." This module supported biological and materials production technologies in the microgravity environment. These included semiconductors, cellular substances, and medicines. Kristall also supported astrophysical and technical experiments. It had a radial docking port, originally designed as a means of docking the Russian Shuttle-type orbiter Buran, and was used for the first STS-71 docking in 1995. Added in June 1990, the 19.6-metric ton Kristall measured 4.4 meters by 13 meters long, with 60.8 cubic meters of volume and 36-meters of solar arrays.

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Spektr

Spektr means "spectrum," and this module allowed for better investigations and monitoring of EarthÆs natural resources and atmosphere. Spektr also supported research into biotechnology, life sciences, materials science, and space technologies. American astronauts sometimes used Spektr as their living quarters. Launched in May 1995 during Norm ThagardÆs mission to Mir, Spektr carried more than 1,600 pounds of U.S. equipment, mainly for biomedical research. Included with its arrival were two pairs of solar arrays to boost power to the station and a Lyappa manipulator arm to assist in moving the modules on Mir. The 19.3-metric ton Spektr module measured 14.4 meters by 4.4 meters, with a pressurized volume of 62 cubic meters, and had four solar arrays. On June 25, 1997, an uncrewed Progress resupply vehicle collided with the Spektr module, causing solar array and hull damage, and depressurization. The Mir crew closed the hatch to the leaking Spektr, preventing further pressure loss onboard Mir.

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Priroda

Priroda means "nature," and this moduleÆs main purpose was Earth remote-sensing including the weather; the ocean-atmosphere system; land, mineral, and crop conditions; and humankindÆs impacts and opportunities in the environment. Priroda also collected information from remote-sensor buoys in nuclear power, seismic activity, and other areas to create an integrated monitoring and warning system. Launched in April 1996, Priroda, the last of the Mir modules arrived during Shannon LucidÆs stay on Mir. The 19.7-metric ton Priroda measured 4.4 meters by 12 meters long and had a pressurized volume of 66 cubic meters.

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Progress Resupply Vehicle

The unmanned, automated Progress was derived from the Soyuz crew transfer vehicle. It was designed to resupply and refuel the Russian Salyut and Mir Space Stations. A Progress typically approached and docked automatically at MirÆs aft docking port, using the Kurs (course) system. During Shuttle-Mir, Progress vehicles supplied Mir about once every two months. They are also used for the International Space Station.

Like the Soyuz, the Progress freighter measured about 7 meters long by 2.7 meters wide. It had 6.6 cubic meters of volume and carried about 2,400 kg of cargo. The refueling compartment of the Progress was replaced with a nonpressurized cargo compartment to enable the transport of materials to be used on the outside of Mir. Progress was also designed to carry small satellites, which could be released by the Mir crews. After being loaded with trash, waste, and other unnecessary items, a Progress undocked and deorbited, to burn up upon reentry over the Pacific Ocean.

Early in the Soviet space station program, crews always got into their Soyuz descent vehicles as a manually guided Progress approached, in case of an accident. The practice was discontinued after successes increased confidence.

See the Progress collision with Mir animation

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Docking Module

The Russian-built Docking Module was delivered by STS-74 on November 14, 1995. Attached to the Kristall, the Docking Module (DM) provided clearance for the Shuttle to dock easily with Mir without interference from the stationÆs solar panels.

The DM featured a pressure-sealed body and an androgynous peripheral docking system (APDS), compatible with the Kristall and Shuttle Orbiter docking systems (ODS). The Shuttle ODS, an external airlock extension, was fitted to the forward payload bay bulkhead and was accessible by the crew via the mid-deck airlock. When docked, the APDS provided locking, structural stiffness, and an airtight seal between the two structures.

The DM was 4.7 meters long from tip to tip of the identical APDSs on either end; its diameter was 2.2 meters; and weighed approximately 4.1 metric tons. The module carried to the Mir two solar arrays: one Russian and one jointly developed by the U.S. and Russia to augment MirÆs power supply. The DM carried the arrays retracted and stowed to be later deployed by cosmonauts.

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Solar Arrays

Electrical power in spacecraft can be produced in many ways; for example from batteries or by nuclear and chemical fuel cells, or by solar cell arrays. Solar panels provided most of the power on Mir, and the station sometimes appeared as if it were "more panel than module." Nevertheless, as one Russian engineer put it, "we never managed to get rid of our energy hunger." Whenever the station lost attitude controlùdue to computer or gyrodyne failuresùrestoring solar power generation was usually the main concern, because almost all the other systems ultimately depended on it.

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Interior

MirÆs interior reflected an environment for work and residency; but more than anything, it contained essential systems, equipment, and materials for survival in space. On a daily basis, crewmembers completed tasks necessary for the station to maintain its existence as well as to provide the conditions vital for the crew.

Over the years, Mir grew more and more crowded and experienced problems with stowage and inventory. The cluttered interior surrounds Aleksandr Lazutkin, Mir-23 Flight Engineer, as he exercises on the ergometer located in the Base Block.

Shuttle Commander Charlie Precourt floats through the crowded pathway to the Kristall that was also used to transfer supplies from the Orbiter to the Mir.

Mission Specialist Chris Hadfield demonstrates the limited space in the Docking Module passageway.

NASA-4 Mir Astronaut Jerry Linenger shown in the Priroda has room to work in the module that was the last to arrive to the complex.

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Soyuz-TM Crew Transport Vehicle

Soyuz means "union," which refers both to the former Soviet Union and to the uniting of spacecraft. The Soyuz-TM spacecraft typically ferried three crewmembers to and from Mir. It remained docked with Mir to be available as an escape vehicle in case of emergency, and was sometimes used to make "fly-around" inspections of the station.

The Soyuz has launched in greater numbers than any other spacecraft in history, providing access to space for more than 30 years. Soyuz-TM has a mass of 7.2 metric tons, a length of 7 meters, a maximum diameter of 2.7 meters, and a pressurized volume of 11 cubic meters. The spacecraft consists of three main sections: orbital module that contains life support, rendezvous, and docking systems, and serves as a crew habitat during nondynamic flight phases; instrument assembly module, a cylindrical shell, that has the orbital flight systems; and the descent module containing the Soyuz main systems control station and is the area where the crew stays during launch and where they conduct orbital maneuvers, rendezvous and docking, and descent. Two solar arrays (10.6-meter span) provide the vehicleÆs electrical power and can be interconnected with MirÆs electrical system to furnish an additional 1.3 kW.

Typically, the journey from the Baikonur launch site to Mir took 50 hours. Transporting crews and cargo to and from the Russian space station, the Soyuz docked on the axial port on the transfer compartment of the core module. Probe-and-drogue devices were used to mate the Soyuz with Mir; the probing rod located on the Soyuz entered the receiving cone located on the space station. After "capture," an electric drive retracted the probe and pulled the two parts of the docking mechanism together. Hooks secured the two assemblies around a docking interface seal. When docking was completed, hatches were opened and the crews began a handover period to exchange information and tasks. At the end of this duration, the departing crew left in the resident Soyuz. The replacement crew moved the Soyuz to another port to allow docking access for the next spacecraft. Because the Soyuz has a limited life in space of 5 to 6 months, the rotation of vehicles guaranteed that the Mir crewmembers had transportation back to Earth. On its return trip, th Soyuz capsule deployed parachutes after reentering the atmosphere, then fired braking rockets when it was just above the ground in Kazakhstan.

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Soyuz in Pravda

Secrecy usually veiled the Soviet space program, but the Soviets sometimes used their space successes to promote an image of technological robustness to both their own citizens and the outside world. At times, detailed descriptions of space exploits and equipment were published, including this one of an early Soyuz model, excerpted from the November 17, 1968 issue of the Soviet newspaper Pravda.

The Soyuz consists of the following main modules: the orbital module à a descent [module], intended for putting crews into orbit and returning them to Earth; and the service module, which houses the à engines.

The orbital module is in the fore part of the ship and is connected with the descent capsule. The service module is placed behind the descent capsule. When the ship is being placed into orbit, it is protected against aerodynamic and thermal overloads by a nose faring, which is jettisoned after the passage through the dense layers of the atmosphere.

The cosmonautÆs cabin [descent module] à is covered on the outside by a à heat-resistant covering to protect it from intensive aerodynamic heating during descent to Earth. After the vehicle has been slowed down by the atmosphere in its descent from orbit, the braking parachute opens à then the main parachute which is used for landing opens. Directly before landing, at a height of about one meter above the Earth, the solid-fuel braking engines of the soft-landing system are switched on.

[In the] service module à a hermetically sealed à container carries the equipment for the thermo-regulation system, the system of unified electric power supply, the equipment for long-range radio communications and radio telemetry, and instruments for the system of orientation and control. The nonpressurized part of the service module contains the liquid-fuel propulsion installation [system] that is used for maneuvering in orbit and à for à descent back to Earth. The installation has two engines (the main one and the spare one). The ship has a system of low-thrust engines for orientation.

The [sensors] for the orientation system are located outside the service module. Mounted on à the service module are the solar [arrays]. To ensure that the solar [arrays] are constantly illuminated, they are oriented towards the Sun by rotating the ship.

The à spaceship is equipped with an automatic docking system. The onboard systems of the ship may be controlled either by the cosmonaut from the control panel or automatically. The shipÆs equipment allows for the craft to be piloted à quite independently of ground control.

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Soyuz Recovery

Following landing of the tiny Soyuz descent module, crewmembers traditionally sign the outside of the capsule in gratitude for a safe landing and return to Earth.

As the Soyuz lands on its single parachute, braking rockets fire about one meter above ground to soften the landing impact. Normally four of the six rocket clusters fire, with the other two clusters held in reserve should the main parachute fail and the smaller backup chute deploy. The two reserve clusters must be disabled prior to transporting the capsule. Here technicians carefully remove one of the engine clusters with its multiple cartridges. The cartridges are then carried a safe distance from the capsule and detonated.

After being transported from the landing site to the nearby airport in Dzhezkazgan by a Mi-8 helicopter, the Soyuz is loaded onto a truck and taken to a temporary storage facility for further processing. It will then be packaged and flown back to Moscow for thorough post-flight analysis by design and construction engineers.

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Mir Expeditions (17-25)

While NASAÆs Space Shuttle typically performs missions of up to two weeks in duration, RussiaÆs Mir expeditions generally lasted about half a year. During Mir Principal Expedition16, cosmonauts unloaded the first U.S. science equipment, which had been launched on Progress 224, and conducted the first U.S. research onboard Mir with that hardware. During Mir-17, cosmonaut Valeri Polyakov set an individual record for time in space of well over a year. The visits to the Russian space station as part of the Shuttle-Mir Program began with Mir Principal Expedition 17 and ended with Mir-25.

Mir Principal Expedition 17

Launched and landed in Soyuz-TM 20
October 3, 1994ûMarch 22, 1995

Mir-17 hosted the first European Space Agency mission aboard Mir, Euromir 94, which ended November 4. Another international milestone was the rendezvous of the Space Shuttle Atlantis with Mir during the STS-63 mission. Cosmonaut Researcher Valeri Polyakov (seen from the window), established a new human spaceflight duration record with his 438-day stay on the station. Also onboard Mir-17 was Commander Aleksandr Viktorenko and Flight Engineer Elena Kondakova.

Mir Principal Expedition 18

Launched in Soyuz-TM 21
March 14, 1995

Landed in Space Shuttle Atlantis
July 7, 1995

The major objectives of the Mir-18 mission were to conduct joint U.S.-Russian medical research and weightlessness effects investigations; to reconfigure the station for the arrival of the Spektr science module; and to welcome the Space Shuttle Atlantis. The mission saw the first American to be part of a Mir crew, NASA-1 Mir Astronaut Norman Thagard (left), the addition of the first new module (Spektr) since Kristall arrived in 1990, and the first docking of a U.S. Space Shuttle (STS-71) with the Mir complex. Pictured with Thagard are Commander Vladimir Dezhurov (center) and Flight Engineer Gennady Strekalov (right).

Mir Principal Expedition 19

Launched in Atlantis (STS-71)
June 27, 1995

Landed in Soyuz-TM 21
September 11, 1995

The only complete Mir mission of 1995 with an all-Russian crew, Mir-19 had many international elements. As the first Mir crew launched on a Space Shuttle (STS-71, Atlantis), Commander Anatoly Solovyev (right) and Flight Engineer Nikolai Budarin (left) began their work in conjunction with the visiting U.S. crew and departing Mir-18 international crew. Two of their extravehicular activities involved deploying and retrieving international experiments. They ended their stay by welcoming the incoming international Euromir 95 crew.

Mir Principal Expedition 20

Launched and landed in Soyuz-TM 22
September 3, 1995ûFebruary 27, 1996

Mir-20 was the second Mir mission with a Euromir designation and the second with a European Space Agency astronaut as part of the crew. Cosmonaut Researcher Thomas Reiter (center) was the first non-Russian Mir crewmember with the added designation of Flight Engineer. Mir-20 was also the second Mir mission to include a U.S. Space Shuttle docking (STS-74, Atlantis). During that phase of the mission, the station complex housed crewmembers from four countries. Representing Russia were Commander Yuri Gidzenko, (left) and Flight Engineer Sergei Avdeyev (right). Reiter represented Germany as a member of the European Space Agency. Chris Hadfield, representing the Canadian Space Agency, arrived with the STS-74 crewùU.S. astronauts Kenneth Cameron, James Halsell, Jr., Jerry Ross, and William McArthur, Jr.

Mir Principal Expedition 21

Launched and landed in Soyuz-TM 23
February 21ûSeptember 2, 1996

Commander Yuri Onufriyenko (right) and Flight Engineer Yury Usachev (center) began their mission without the third crewmember, NASA-2 Mir Astronaut Shannon Lucid (left), who would join them on March 23 during STS-76, the third Atlantis-Mir docking mission. On one of the seven extravehicular activities during Mir-21, two STS-76 astronauts, Linda Godwin and Michael (Rich) Clifford, walked outside Mir; the first U.S. extravehicular activity (EVA) outside the two mated spacecraft and the first U.S. spacewalk outside a space station since Skylabù22 years earlier. On two other EVAs, Onufriyenko and Usachev installed a new solar array on the Kvant module. In May 1996, the last permanent module was added to the complex, Priroda, with its large complement of Earth science experiments.

Mir Principal Expedition 22

Launched and landed in Soyuz-TM 24
August 17, 1996ûMarch 2, 1997

Commander Valeri Korzun (top right), Flight Engineer Alexander Kaleri (top left), and French Researcher Claudie Andre-Deshays (bottom center) joined Shannon Lucid (top center) and the Mir-21 crew, Commander Yuri Onufriyenko (bottom right) and Flight Engineer Yury Usachev (bottom left), on Mir. Andre-Deshays returned to Earth with the Mir-21 crew after about two weeks onboard the station. LucidÆs stay with the Mir-22 Expedition crew was lengthened about six weeks due to a Space Shuttle launch postponement. STS-79 launched on September 16, 1996, delivering NASA-3 resident John Blaha and returning home with Lucid onboard on September 26. STS-81 launched on January 12, 1997, with the next U.S. resident, Jerry Linenger, who later performed a spacewalk in a Russian Orlan spacesuit.

Mir Principal Expedition 23

Launched and landed Soyuz-TM 25
February 10, 1997ûAugust 14, 1997

Mir-23 had more troubles than any other Mir expedition, including an onboard fire that occurred early in the mission with six crewmembers onboardùMir-22 crew, Valeri Korzun, Alexander Kaleri and German Researcher Reinhold Ewald; Mir-23 crew, Commander Vasily Tsibliev (left) and Flight Engineer Aleksandr Lazutkin (right); and NASA-4 resident Jerry Linenger (center). Challenges continued for the Mir-23 crew after NASA-5 Mir Astronaut Mike Foale arrived on STS-84, when a Progress resupply vehicle collided with MirÆs Spektr module, causing a loss of station control and depressurization.

Mir Principal Expedition 24

Launched and landed Soyuz-TM 26
August 5, 1997ûFebruary 15, 1998

Mir-24 hosted three American astronauts, NASA-5 resident Mike Foale, NASA-6 resident David Wolf (center), and NASA-7 resident Andy Thomas. Mir continued to have systems problems, but overall conditions improved. Wolf performed an extravehicular activity with Commander Anatoly Solovyev (right). Also onboard Mir-24 was Flight Engineer Pavel Vinogradov (left).

Mir Principal Expedition 25

Launched and landed Soyuz-TM 27
January 29, 1998ûAugust 25, 1998

Mir-25 was the last Shuttle-Mir expedition. French Astronaut Leopold Eyharts flew to Mir with the Mir-25 crew and returned to Earth with the Mir-24 crew. Russian Phase 1 Manager Valery Ryumin visited Mir with the crew of STS-91, which brought NASA-7 Mir Astronaut Andy Thomas back to Earth. Mir-25 crewmembers were Commander Talgat Musabayev and Flight Engineer Nikolai Budarin. Pictured are (top row, left to right) Ryumin, STS-91 crewmember Wendy Lawrence, Thomas, STS-91 crewmember Janet Kavandi, Budarin; (bottom row, left to right) STS-91 Commander Charlie Precourt, Musabayev, and STS-91 crewmembers Dominic Gorie and Franklin Chang-Diaz.