The Soyuz (saw-yooz) is a Russian spacecraft. The Soyuz carries people and supplies to and from the space station. The Soyuz can also bring people back to Earth. Russia helps the United States run the International Space Station. Other countries also help with the space station. But only Russian spacecraft carry people to it right now. [Source: NASA]

The Soyuz takes cosmonauts and astronauts to and from the space station. A Soyuz has room for three people to ride in it. The spacecraft also brings food and water to the space station. The Soyuz is like a lifeboat. At least one Soyuz is always attached to the space station. If there were an emergency on the space station, the crew could use the Soyuz to leave the space station and return to Earth.

The Soyuz has two parts. One part is the Soyuz capsule. The second part is the Soyuz rocket. The Soyuz capsule sits on top of the Soyuz rocket. The capsule has three parts. The parts are also called modules. The first part of the capsule is the Orbital Module. The crew members live in the Orbital Module while they are in orbit. This module is about the size of a large van. The Orbital Module can connect to the space station. The second part of the capsule is the Descent Module. “To descend” means to go down. The crew sits in this part when the Soyuz is launching to the space station. They also use the Descent Module for landing on Earth. The third module is home to the life support systems. It holds things like batteries, solar panels and steering engines.

Soyuz Launch, Docking and Landing

The Soyuz capsule launches on top of a Soyuz rocket. A rocket is what launches people and objects into space. After the launch, the capsule and the rocket separate. The rocket part of the Soyuz returns to Earth. The Soyuz capsule keeps going, and takes only nine minutes to reach space! [Source: NASA]

The Soyuz takes just six hours to get to the space station. The crew uses the hatch on the Soyuz to enter and leave the station. When the crew is ready to come home, they ride in the Soyuz capsule back to Earth. The Soyuz does not land like an airplane because the Soyuz does not have wheels or wings.

The rendezvous and docking are both automated, although once the spacecraft is within 492 feet of the Station, the Russian Mission Control Center just outside Moscow monitors the approach and docking. The Soyuz crew has the capability to manually intervene or execute these operations.

To land, the Soyuz drops through Earth's atmosphere. The atmosphere slows the Soyuz. The Soyuz uses parachutes to slow down even more. When the Soyuz gets close to the ground, it fires small rocket engines to slow down more. Even then, the landing is bumpy. The Soyuz lands in the grassy plains of Kazahkstan. After leaving the space station, the Soyuz takes only 3 1/2 hours to land!

Soyuz Modules

The Soyuz spacecraft consists of an Orbital Module, a Descent Module and an Instrumentation/Propulsion Module. The Orbital Module is used by the crew while on orbit during free-flight, providing the crew with extra living space during the trip to the station. It contains systems vital to rendezvous and docking with the station's Pirs Docking Compartment or other port: a docking mechanism, a hatch and rendezvous antennas.

The Orbital Module has a volume of 230 cubic feet, with a docking mechanism, hatch and rendezvous antennas located at the front end. The docking mechanism is used to dock with the space station and the hatch allows entry into the station. The rendezvous antennas are used by the automated docking system -- a radar-based system -- to maneuver towards the station for docking. There is also a window in the module. The opposite end of the Orbital Module connects to the Descent Module via a pressurized hatch. Before returning to Earth, the Orbital Module separates from the Descent Module -- after the deorbit maneuver -- and burns up upon re-entry into the atmosphere.[Source: NASA, October 22, 2010]

The Descent Module is where the cosmonauts and astronauts sit for launch, re-entry and landing. All the necessary controls and displays of the Soyuz are located here. The module also contains life support supplies and batteries used during descent, as well as the primary and backup parachutes and landing rockets. It also contains custom-fitted seat liners for each crew member's couch/seat, which are individually molded to fit each person's body -- this ensures a tight, comfortable fit when the module lands on the Earth. When crewmembers are brought to the station aboard the space shuttle, their seat liners are brought with them and transferred to the existing Soyuz spacecraft as part of crew handover activities.

The module has a periscope, which allows the crew to view the docking target on the station or the Earth below. The eight hydrogen peroxide thrusters located on the module are used to control the spacecraft's orientation, or attitude, during the descent until parachute deployment. It also has a guidance, navigation and control system to maneuver the vehicle during the descent phase of the mission. This module weighs 6,393 pounds, with a habitable volume of 141 cubic feet. Approximately 110 pounds of payload can be returned to Earth in this module and up to 331 pounds if only two crewmembers are present. The Descent Module is the only portion of the Soyuz that survives the return to Earth.

The Instrumentation/Propulsion Module contains three compartments: Intermediate, Instrumentation and Propulsion. The intermediate compartment is where the module connects to the Descent Module. It also contains oxygen storage tanks and the attitude control thrusters, as well as electronics, communications and control equipment. The primary guidance, navigation, control and computer systems of the Soyuz are in the instrumentation compartment, which is a sealed container filled with circulating nitrogen gas to cool the avionics equipment.

The propulsion compartment contains the primary thermal control system and the Soyuz radiator, which has a cooling area of 86 square feet. The propulsion system, batteries, solar arrays, radiator and structural connection to the Soyuz launch rocket are located in this compartment. The propulsion compartment contains the system that is used to perform any maneuvers while in orbit, including rendezvous and docking with the Space Station and the deorbit burns necessary to return to Earth. The propellants are nitrogen tetroxide and unsymmetric-dimethylhydrazine. The main propulsion system and the smaller reaction control system, used for attitude changes while in space, share the same propellant tanks.

The two Soyuz solar arrays are attached to either side of the rear section of the Instrumentation/Propulsion Module and are linked to rechargeable batteries. Like the Orbital Module, the intermediate section of the Instrumentation/Propulsion Module separates from the Descent Module after the final deorbit maneuver and burns up in atmosphere upon re-entry.

Soyuz TMA

The Soyuz TMA spacecraft was used between 2002 and 2012. It replaced the Soyuz TM, which was used from May 1986 to November 2002 to take astronauts and cosmonauts to Mir and then to the International Space Station beginning in November 2000. [Source: NASA, October 22, 2010]

The TMA increased safety, especially in descent and landing. It had smaller and more efficient computers and improved displays. In addition, the Soyuz TMA accommodated individuals as large as 6 feet, 3 inches tall and 209 pounds, compared to 6 feet and 187 pounds in the earlier TM. Minimum crewmember size for the TMA was 4 feet, 11 inches and 110 pounds, compared to 5 feet, 4 inches and 123 pounds for the TM.

Two new engines reduced landing speed and forces felt by crewmembers by 15 to 30 percent and a new entry control system and three-axis accelerometer increased landing accuracy. Instrumentation improvements included a color "glass cockpit," which was easier to use and gave the crew more information, with hand controllers that could be secured under an instrument panel. All the new components in the Soyuz TMA could spend up to one year in space.

New components and the entire TMA were rigorously tested on the ground, in hangar-drop tests, in airdrop tests and in space before the spacecraft was declared flight-ready. For example, the accelerometer and associated software, as well as modified boosters (incorporated to cope with the TMA's additional mass), were tested on flights of Progress unpiloted supply spacecraft, while the new cooling system was tested on two Soyuz TM flights.

Descent module structural modifications, seats and seat shock absorbers were tested in hangar drop tests. Landing system modifications, including associated software upgrades, were tested in a series of airdrop tests. Additionally, extensive tests of systems and components were conducted on the ground.

Latest Soyuz

The Soyuz TMA-M was used from 2010 to 2016. I was an upgrade of the baseline Soyuz-TMA, using a new computer, digital interior displays, updated docking equipment, and the vehicle's total mass was reduced by 70 kilograms. The new version debuted on 7 October 2010 with the launch of TMA-01M, carrying the ISS Expedition 25 crew. The Soyuz TMA-08M mission set a new record for the fastest manned docking with a space station, event utilized the new six-hour fast rendezvous instead of the previous Soyuz launches which had, since 1986, taken two days. [Source: Wikipedia]

Soyuz MS is the final planned upgrade of the Soyuz spacecraft. Its maiden flight is expected to happen in 2016. Major changes include: 1) more efficient solar panels; 2) modified docking and attitude control engine positions for redundancy during docking and de-orbit burns; 3) new Kurs NA approach and docking system which weighs half as much and consumes a third of the power of previous system.

4) new TsVM-101 computer, about one eighth the weight (8.3 kg vs. 70 kg) and much smaller than the previous Argon-16 computer; 5) unified digital command/telemetry system (MBITS) to relay telemetry via satellite, and control spacecraft when out of sight of ground stations; also provides the crew with position data when out of ground tracking range; 6) GLONASS/GPS and Cospas-Sarsat satellite systems for more accurate location during search/rescue operations after landing

Soyuz Launch Rockets

Throughout history, more than 1,500 launches have been made with Soyuz launchers to orbit satellites for telecommunications, Earth observation, weather and scientific missions, as well as for human flights. The basic Soyuz vehicle is considered a three-stage launcher in Russian terms and is composed of: 1) a lower portion consisting of four boosters in the first stage and a central core in the second stage; 2) an upper portion, consisting of the third stage, payload adapter and payload fairing. Liquid oxygen and kerosene are used as propellants in all three Soyuz stages. [Source: Jerry Wright, NASA, Sept. 25, 2013]

First Stage Boosters The four boosters of the first stage are assembled laterally around the second stage central core. The boosters are identical and cylindrical-conic in shape with the oxygen tank located in the cone-shaped portion and the kerosene tank in the cylindrical portion. An NPO Energomash RD 107 engine with four main chambers and two gimbaled vernier thrusters is used in each booster. The vernier thrusters provide three-axis flight control.

An NPO Energomash RD 108 engine powers the Soyuz second stage. This engine differs from those of the boosters by the presence of four vernier thrusters, which are necessary for three-axis flight control of the launcher after the first stage boosters have separated. An equipment bay located atop the second stage operates during the entire flight of the first and second stages. The third stage is linked to the Soyuz second stage by a latticework structure.

Launch of a Soyuz Rocket

Soyuz missions use the Baikonur Cosmodrome's proven infrastructure, and launches are performed by trained personnel with extensive operational experience. Two launch pads are dedicated to Soyuz missions. The assembled launch vehicle is moved to the launch pad on a horizontal railcar. Transfer to the launch zone occurs two days before launch, during which the vehicle is erected and a launch rehearsal is performed that includes activation of all electrical and mechanical equipment. On launch day, the vehicle is loaded with propellant and the final countdown sequence is started at three hours before the liftoff time. [Source: Jerry Wright, NASA, Sept. 25, 2013]

Ignition of the first stage boosters and the second stage central core occur simultaneously on the ground. When the boosters have completed their powered flight during ascent, they are separated, and the core second stage continues to function. First stage booster separation occurs when the predefined velocity is reached, which is about 118 seconds after liftoff.

When the second stage's powered flight is complete, the third stage engine is ignited. Separation of the two stages occurs by the direct ignition forces of the third stage engine. A single-turbopump RD 0110 engine from KB KhA powers the Soyuz third stage.

The third stage engine is fired for about 240 seconds, and cutoff occurs when the calculated velocity increment is reached. After cutoff and separation, the third stage performs an avoidance maneuver by opening an outgassing valve in the liquid oxygen tank.

Soyuz launcher tracking and telemetry is provided through systems in the second and third stages. These two stages have their own radar transponders for ground tracking. Individual telemetry transmitters are in each stage. Launcher health status is downlinked to ground stations along the flight path. Telemetry and tracking data are transmitted to the Russian Mission Control Center, where the incoming data flow is recorded. Partial realtime data processing and plotting are performed for flight following an initial performance assessment. All flight data is analyzed and documented within a few hours after launch.

Soyuz and the International Space Station

The Russian Soyuz space capsule became the only means for astronauts to reach and leave the International Space Station after the U.S. Space shuttle fleet was decommissioned in 2011. A Soyuz space capsule took the first crew to the International Space Station in November 2000. Since that time, at least one Soyuz has always been at the Station, generally to serve as a lifeboat should the crew have to return to Earth unexpectedly. After the Columbia accident in February 2003, the Soyuz TMA became the means of transportation for crewmembers going to or returning from the orbiting laboratory. [Source: NASA]

Once the Soyuz reaches orbit, it spends two days chasing the Station. The crew performs systems checks and keeps in touch with controllers at the Russian Mission Control Center during that time. Before the final rendezvous phase, the crewmembers put on pressurized suits and then monitor the automated docking sequence. The rendezvous and docking are both automated, but the Soyuz crew has the capability to manually intervene or execute these operations. Once docking is complete, the crewmembers equalize the air pressure of the Soyuz with the Station before opening the hatches.

At least one Russian Soyuz spacecraft is always docked to the Space Station. In addition, there is usually a Progress supply vehicle docked and sometimes a Space Shuttle as well. The Station is well supplied with docking ports for all three types of vehicles.

Up to three crewmembers can launch and return to Earth from the Station aboard a Soyuz TMA spacecraft. The vehicle lands on the flat steppes of Kazakhstan in central Asia. A Soyuz trip to the station takes two days from launch to docking, but the return to Earth takes less than 3.5 hours. In September 2012, Soyuz undocked from the ISS somewhere over Kenya and landed in Kazakhstan three and a half hours later.

Soyuz TMA Landing

Up to three crew members can return to Earth from the International Space Station aboard a Soyuz TMA spacecraft. The vehicle lands on the flat steppe of Kazakhstan in central Asia. The return to Earth takes less than 3.5 hours. The three elements of the Soyuz TMA spacecraft — the Orbital Module, the Descent Module and the Instrumentation/Propulsion Module — are attached end-to-end. The crew occupies the central element, the Descent Module. The other two modules are jettisoned prior to re-entry. They burn up in the atmosphere, so only the Descent Module returns to Earth. [Source: Jerry Wright, NASA, July 31, 2015]

Once the Soyuz departs, the Orbital Module is no longer needed, so it is jettisoned about three hours after undocking. The Instrumentation/Propulsion Module is shed at the same time, about half an hour after its engines perform their final task -- a deorbit burn that drops the Soyuz from orbit. With it go the spacecraft's two solar arrays. This module contains the primary guidance, navigation and computer systems for the vehicle.

A secondary guidance, navigation and control system in the Descent Module enables the crew to maneuver the vehicle after the Instrumentation/Propulsion Module has been jettisoned. The Soyuz commander can pilot the module using a rotational hand controller that manages the firing of eight hydrogen peroxide thrusters on the vehicle's exterior. This system is deactivated 15 minutes before landing, when the parachutes are deployed.

Cushioning the Landing

Having shed two-thirds of its mass, the Soyuz reaches Entry Interface -- a point 400,000 feet above the Earth, where friction due to the thickening atmosphere begins to heat its outer surfaces -- three hours after undocking. With only 23 minutes left before it lands on the grassy plains of central Asia, attention in the module turns to slowing its rate of descent. [Source: Jerry Wright, NASA, July 31, 2015]

Eight minutes later, the spacecraft is streaking through the sky at a rate of 755 feet per second. Before it touches down, its speed will slow to only 5 feet per second, and it will land at an even lower speed than that. Several onboard features ensure that the vehicle and crew land safely and in relative comfort.

Four parachutes, deployed 15 minutes before landing, dramatically slow the vehicle's rate of descent. Two pilot parachutes are the first to be released, and a drogue chute attached to the second one follows immediately after. The drogue, measuring 24 square meters (258 square feet) in area, slows the rate of descent from 755 feet per second to 262 feet per second. The main parachute is the last to emerge. It is the largest chute, with a surface area of 10,764 square feet. Its harnesses shift the vehicle's attitude to a 30-degree angle relative to the ground, dissipating heat, and then shift it again to a straight vertical descent prior to landing.

The main chute slows the Soyuz to a descent rate of only 24 feet per second, which is still too fast for a comfortable landing. One second before touchdown, two sets of three small engines on the bottom of the vehicle fire, slowing the vehicle to soften the landing. Further cushioning the impact of landing are the crew seats with their custom-fitted liners. The liners are made preflight, individually molded to fit each person's body -- this ensures a tight, comfortable fit when the module lands on the Earth. When crew members were brought to the station aboard the space shuttle, their seat liners were delivered with them and transferred to the existing Soyuz spacecraft as part of crew handover activities.

TMA Improvements for Landing

Soyuz TMA seats accommodate both larger and smaller occupants than the older model, and seat shock absorbers have been modified to suit the varying loads. The Soyuz TMA spacecraft is a replacement for the Soyuz TM, which was used from May 1986 to November 2002 to take astronauts and cosmonauts to Mir and then to the International Space Station beginning in November 2000. [Source: Jerry Wright, NASA, July 31, 2015]

The TMA increases safety, especially in descent and landing. Two new engines reduce landing speed and forces felt by crew members by 15 to 30 percent, and a new entry control system and three-axis accelerometer increase landing accuracy. Instrumentation improvements include a color "glass cockpit," which is easier to use and gives the crew more information, with hand controllers that can be secured under an instrument panel. All the new components in the Soyuz TMA can spend up to one year in space.

Descent module structural modifications, seats and seat shock absorbers were tested in hangar drop tests. Landing system modifications, including associated software upgrades, were tested in a series of airdrop tests. Additionally, extensive tests of systems and components were conducted on the ground.

Safe Landing of Soyuz in Kazakhstan

Describing the landing of the Soyuz TMA-16M in September 2015, William Harwood wrote in Spaceflight Now, “Three space station crew members — two short timers completing a 10-day flight and a veteran cosmonaut who has logged a world record 879 days aloft over five missions — undocked from the International Space Station and returned to Earth, landing safely on the steppe of Kazakhstan. With veteran commander Gennady Padalka strapped into the descent module’s center seat, flanked on the left by European Space Agency flight engineer Andreas Mogensen and on the right by Kazakh cosmonaut Aidyn Aimbetov, the Soyuz TMA-16M spacecraft separated from the aft port of the station’s Zvezda command module at 5:29 p.m. EDT (GMT-4). “Goodbye station,” one of the crew member radioed. [Source: William Harwood, Spaceflight Now, September 12, 2015 ^^^]

“After moving a safe distance away from the lab complex, Padalka monitored a programmed four-minute 42-second firing of the spacecraft’s braking rockets that slowed the ship by 286 mph, just enough to drop the far side of its orbit deep into Earth’s atmosphere on a trajectory targeting central Kazakhstan. Twenty-three minutes later, just above the discernible atmosphere, the Soyuz TMA-16M spacecraft’s three modules separated and the central crew compartment, oriented heat shield first, continued the descent. After exiting the zone of peak heating, the spacecraft’s large orange-and-white parachute deployed. “We are coming back to Earth, to our hospitable planet,” Padalka said as the spacecraft descended, visible in spectacular video shot by the Roscosmos, the Russian federal space agency. ^^^

“Moments later, the crew compartment settled to a jarring rocket-assisted touchdown at 8:51:36 p.m. EDT (6:51 a.m. Saturday local time), tilting over on its side. Russian recovery forces stationed nearby rushed to the landing site to help the returning station fliers get out of the cramped descent module for initial medical checks and satellite phone calls home to family and friends. Resting in recliners near the charred descent module, all three crew members appeared healthy and in good spirits, smiling and chatting with support crews and enjoying fresh apples and tea.

After more extensive medical checks, Padalka, Mogensen and Aimbetov, only the third Kazakh to fly in space, were scheduled to fly by helicopter to Astana, the capital of Kazakhstan, for an official welcoming ceremony with President Nursultan Nazarbayev. This was Padalka’s fifth space mission, giving him a total time aloft of 878.5 days, more than two months longer than the previous record set by cosmonaut Sergei Krikalev. The current U.S. record is held by NASA astronaut Mike Fincke, who logged 382 days in space over three flights.

Soyuz Misses Landing Target by Hundreds of Kilometers

In May 2003, in the first landing following the Columbia space shuttle disaster, a Soyuz spacecraft safely delivered a three-man, U.S.-Russian crew to Earth but landed hundreds of kilometers from where it was supposed to land, way beyond of reach of search-and-rescue helicopters. Marcia Dunn wrote in the Moscow Times, “Russian spotters found the capsule on the scrub-covered steppe north of the Aral Sea after a nerve-racking, two-hour air search for the two Americans — the first U.S. astronauts to land on foreign soil and in a foreign spacecraft — and the Russian. The three crewmen had opened the hatch and climbed out of the spacecraft, and stood waving at the search plane. [Source: Marcia Dunn, Moscow Times, May, 5 2003 <<<]

“The head of U.S. space agency NASA, Sean O'Keefe, admitted he had been nervous but he put a positive spin on the landing and lauded the Russian-U.S. cooperation. "At the time when we needed them most, Russia, our partners, have excelled," O'Keefe told reporters at Mission Control outside Moscow. "Today's challenge further demonstrates that space exploration is a very, very risky business. Today's success story is that the international space station goes on because of their [the Russians'] commitment."

“Ten search helicopters carrying NASA doctors, Russian Aviation and Space Agency and military officials and journalists set out from Astana to find the capsule. Crew members listened in to radio updates on the progress of the Soyuz's descent, and everything appeared to be going well. But at the appointed touchdown time, no parachutes or capsule could be seen in the clear sky or on the barren steppe. In one helicopter, two Russian air force officers huddled together, each holding half of one headset to an ear. As the minutes wore on, they gestured to the others on board that nothing had been heard from the spacecraft or seen on the ground. The helicopters finally headed back to Astana -- leaving the spotting to other aircraft. "Nervous. Nervous. This landing was unusual," said Talgat Musabayev, a cosmonaut who...was in one of the helicopters that returned to Astana. <<<

“At Mission Control, elation over the landing turned to confusion. There were conflicting reports of where the capsule had landed and whether communications had been established. Finally, Mission Control announced that the capsule had landed just north of the Aral Sea. The landing site was some 460 kilometers southwest of the target, said NASA spokesman Rob Navias. The capsule had landed on its side and apparently been dragged about 12 meters, probably by the main parachute. During the 3 1/2-hour flight back to the Moscow area, Bowersox told The Associated Press that he and his crewmates were well aware that they would land short of the touchdown site, but were not too worried. "I was just happy we were down, that everything was safe," he said. "It was the most beautiful dirt I've ever seen." <<<

“Allard Beutel, a NASA official at Mission Control, said the capsule had landed on a steeper trajectory than expected. A Russian ballistic researcher, Nikolai Ivanov, said such a descent would have increased the force of gravity to G-9, well above the maximum planned G-7 but still within a range the astronauts could tolerate. He also said that the so-called ballistic descent could have adversely affected the capsule's communications system, hampering the search-and-rescue efforts. Yury Semyonov, director of Energia, the company that builds spacecraft, said human error could not be excluded: Someone could have pulled one lever when they intended to reach for another. It was the first time the new Soyuz model had gone through a descent. "We very often get used to the fact that everything will work as normal," said Russian Aviation and Space Agency chief Yury Koptev. "But space is a new horizon.” The three crewmen spent 5 1/2 months aboard the space station -- two months longer than planned because after the Columbia accident extra time was needed to bring their replacements aboard another Soyuz.” <<<

Image Sources:

Text Sources: New York Times, Washington Post, Los Angeles Times, Times of London, Lonely Planet Guides, Library of Congress, U.S. government, Compton’s Encyclopedia, The Guardian, National Geographic, Smithsonian magazine, The New Yorker, Time, Newsweek, Reuters, AP, AFP, Wall Street Journal, The Atlantic Monthly, The Economist, Foreign Policy, Wikipedia, BBC, CNN, and various books, websites and other publications.

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© 2008 Jeffrey Hays

Last updated May 2016

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