# Soyuz MS

The Soyuz MS (Russian: Союз МС; GRAU: 11F732A48) is the latest version of the Russian Soyuz spacecraft series, first launched in 2016. The "MS" stands for "modernized systems," reflecting upgrades primarily focused on the communications and navigation subsystems. An evolution of the Soyuz TMA-M spacecraft, the Soyuz MS features minimal external changes, mainly in the placement of antennas, sensors, and thrusters. It is used by Roscosmos for human spaceflight missions.
Soyuz MS-01 conducted its maiden flight on 7 July 2016, heading to the International Space Station (ISS). The mission included a two-day checkout phase to validate the spacecraft’s new design before docking with the ISS on 9 July 2016. After remaining docked to the ISS for 113 days, the crew of MS-01 returned to Earth on 30 October 2016, safely landing on the Kazakh Steppe.
The spacecraft has experienced one in-flight abort during the Soyuz MS-10 mission. Shortly after the four boosters of its Soyuz FG carrier rocket separated, one collided with its core stage. The spacecraft’s onboard computer activated the launch escape system, which performed flawlessly, quickly pulling the reentry and orbital modules away from the failing rocket. Once at a safe distance, the system jettisoned the reentry module, allowing it to descend to the ground under parachutes. The crew landed unharmed.

## Design

Like all previous variants, the Soyuz MS spacecraft consists of three parts (from forward to aft in space and top to bottom when mounted on a rocket):
* A spheroid orbital module,
* A small aerodynamic descent module,
* A cylindrical instrumentation/propulsion module
The orbital and descent modules contain the pressurized habitable living space. By moving as much equipment and space as possible into the orbital module, which does not have to be shielded or decelerated during re-entry, the Soyuz three-part craft is larger and lighter than two-part designs. By comparison, the Apollo spacecraft's pressurized command module provided a crew of three six cubic metres (210 cu ft) of living space and had a reentry mass of 5,000 kilograms (11,000 lb); while the Soyuz MS provides the same crew with ten cubic metres (350 cu ft) of living space while the reentry module weighs 2,950 kilograms (6,500 lb).
Soyuz can carry up to three cosmonauts and provide life support for them for about 30 person-days. The life support system provides a nitrogen/oxygen atmosphere at sea level partial pressures. The atmosphere is regenerated through KO$_2$ cylinders, which absorb most of the CO$_2$ and water produced by the crew and regenerates the oxygen, and LiOH cylinders which absorb leftover CO$_2$. Estimated deliverable payload weight is up to 200 kg and up to 65 kg can be returned.
The vehicle is protected during launch by a nose fairing with a launch escape system, which is jettisoned after passing through the atmosphere. The spacecraft is highly automated, and its Kurs system is capable of navigating to an automatic docking at the ISS. However, a pilot can operate the spacecraft independently of ground control if necessary.

### Orbital module

The forward-most section of the spacecraft is the orbital module (Russian: Бытовой Отсек [БО], romanized: Bitovoy Otsek [BO]), also referred to as the habitation module.
The module features three ports. The forward port is used for docking with the ISS, the side port is used for crew entry during ground operations and potential spacewalks, and the aft port connects to the reentry module.
Designed for multiple purposes, the orbital module provides living space for the crew while in orbit, including a toilet and additional room compared to the confined reentry module. It can hold over 100 kilograms (220 lb) of cargo during launch. Since the module is jettisoned and destroyed before reentry, it is typically packed with up to 170 kilograms (370 lb) of waste before being sealed off.
The modular design enables customization for specific missions without compromising the critical systems of the reentry module. In zero gravity, the module’s orientation differs from the reentry module's, with cosmonauts standing or sitting with their heads toward the docking port.
The orbital module of the Soyuz MS includes a small forward-facing window, which allows the crew, particularly the flight engineer, to assist the commander with manual docking if automated systems fail.
A hatch between the orbital and descent modules can be sealed, allowing the orbital module to serve as an airlock. Cosmonauts could theoretically exit through the side port, though this feature has never been used, as the ISS provides larger, dedicated airlocks. The side port is the crew’s entry point when boarding the spacecraft on the launch pad.
Compared to previous versions, the orbital module of the Soyuz MS has additional anti-meteoroid shielding.

### Descent module

The mid-section of the spacecraft is the reentry module (Russian: Спускаемый Аппарат [СА], romanized: Spuskaemiy Apparat [SA]). It is where the crew is seated for launch and the journey back to Earth. It is covered by a heat-resistant covering to protect it during re-entry. It is slowed initially by the atmosphere, then by a braking parachute, followed by the main parachute, which slows the craft for landing. At one meter above the ground, solid-fuel braking engines mounted behind the heat shield are fired to give a soft landing. One of the design requirements for the reentry module was for it to have the highest possible volumetric efficiency (internal volume divided by hull area). The best shape for this is a sphere, but such a shape can provide no lift, which results in a purely ballistic reentry. Ballistic reentries are hard on the occupants due to high deceleration and can't be steered beyond their initial deorbit burn. That is why it was decided to go with the "headlight" shape that the Soyuz uses — a hemispherical forward area joined by a barely angled conical section (seven degrees) to a classic spherical section heat shield. This shape generates a small amount of lift due to the unequal weight distribution. The nickname was coined when nearly every automobile headlight was a circular paraboloid.

### Instrumentation/propulsion module

The aft-most section of the spacecraft is the instrumentation/propulsion module (Russian: Приборно-Агрегатный Отсек [ПАО], romanized: Priborniy-Agregatniy Otsek [PAO]), also referred to as the service module or aggregate compartment. It is subdivided into three main sections: the intermediate compartment, the instrumentation compartment, and the propulsion compartment.
The instrumentation compartment (Russian: Приборно Отсек [ПО], romanized: Priborniy Otsek [PO]), is a pressurized container shaped like a bulging can that contains systems for temperature control, electric power supply, long-range communications, telemetry, and instruments for orientation and control. The propulsion compartment (Russian: Агрегатный Отсек [АО], romanized: Agregatniy Otsek [AO]), a non-pressurized part of the service module, contains the main engine and a spare: liquid-fuel propulsion systems for maneuvering in orbit and initiating the descent back to Earth. The spacecraft also has a system of low-thrust engines for orientation, attached to the intermediate compartment (Russian: Переходной Отсек [ПхО], romanized: Perekhodnoi Otsek [PkhO]). Outside the service module are the sensors for the orientation system and the solar array, which is oriented towards the sun by rotating the spacecraft.

### Re-entry procedure

Because its modular construction differs from that of previous designs, the Soyuz has an unusual sequence of events prior to re-entry. The spacecraft is turned engine-forward and the main engine is fired for de-orbiting fully 180° ahead of its planned landing site. This requires the least propellant for re-entry, the spacecraft traveling on an elliptical Hohmann orbit to a point where it will be low enough in the atmosphere to re-enter.
Early Soyuz spacecraft would then have the service and orbital modules detach simultaneously. As they are connected by tubing and electrical cables to the descent module, this would aid in their separation and avoid having the descent module alter its orientation. Later, the Soyuz spacecraft detaches the orbital module before firing the main engine, which saves even more propellant and enables the descent module to return more payload. The orbital module cannot remain in orbit as an addition to a space station, as the hatch, which enables it to function as an airlock, is part of the descent module.
The parachute system is activated at an altitude of about 10 kilometres (6.2 mi). Two pilot parachutes deploy first, followed by a drogue chute that slows the spacecraft from 230 to 80 metres per second (830 to 290 km/h; 510 to 180 mph). The main parachute then deploys, further reducing the descent rate to 7.2 metres per second (26 km/h; 16 mph). The heat shield is jettisoned at an altitude of about 5.8 kilometres (3.6 mi), revealing six solid-propellant soft-landing motors that fire just 1 metre (3.3 ft) above the ground, slowing the descent rate to less than 2 metres per second (7.2 km/h; 4.5 mph). The seats inside the descent module, which are fitted with shock absorbers and liners custom molded to each crew member's body shape, cushion the final impact.
Soyuz missions typically land in the evening so that recovery helicopters can more easily see the spacecraft as it descends in the twilight, illuminated by the sun when it is above the shadow of the Earth. Since the beginning of Soyuz missions to the ISS, only five have performed nighttime landings.

## Soyuz MS improvements

The Soyuz MS received the following upgrades with respect to the Soyuz TMA-M:
* Apparatus for Satellite Navigation (ASN-K, Russian: Аппаратура Спутниковой Навигации [АСН-К], romanized: Apparatura Sputnikovoi Navigatsii): Instead of relying on six ground stations to determine its orbital path, the new ASN-K will use GLONASS and GPS signals. Compared to the prior system, ASN-K is far less bulky and can be used to locate the Soyuz descent capsule on the ground after landing. It uses four fixed antennas to achieve a positioning accuracy of 5 m (16 ft) and aims to reduce that number to as little as 3 cm (1.2 in) and to achieve an attitude accuracy of 0.5°.
* New Kurs-NA rendezvous system: The new Kurs-NA (Russian: Курс-Новая Активная, romanized: Kurs-Novaya Aktivnaya, lit. 'Course-New Active') automatic docking system is designed and manufactured in Russia, replacing its Ukrainian predecessor. This change addresses a political problem (with the two countries at war) and enhances the system’s capabilities with a higher level of computerization. While the original Kurs system was highly reliable over the years, many of its electronic components have become outdated. The Kurs-NA is 25 kg (55 lb) lighter, 30% smaller, and consumes 25% less power. Additionally, it features a single phased-array antenna, replacing four antennas on the older system, while the two narrow-angle antennas have been retained although re-positioned further toward the rear. To assist with docking, the old halogen headlight has been replaced with a brighter, more energy-efficient LED light.
* Unified Command and Telemetry System (EKTS, Russian: Единая Командно-Телеметрическая Система, romanized: Edinaya Komandno-Telemetricheskaya Sistema): Instead of solely relying on ground stations in Russian territory, the spacecraft has a satellite-capable communications system, EKTS, that connects to Russia's Luch system, providing coverage 83 percent of the day. It also retains very high frequency (VHF) and ultra high frequency (UHF) radios for communications with ground stations. The large EKTS S-band satellite antenna array, one of the most prominent new features on the ship's exterior, is also capable of communicating via American TDRS and Europe's EDRS satellites. The EKTS integrates several previous systems, including the BRTS (radio), MBITS (telemetry), and Rassvet (radio voice), which have been replaced or upgraded for compatibility. Additionally, it features a COSPAS-SARSAT transponder for real-time location tracking during reentry and landing. These changes enable the Soyuz to use the same ground segment terminals as the Russian Segment of the ISS.
* Re-arranged attitude control thrusters: the Integrated Propulsion System (Russian: Комбинированная Двигательная Установка, romanized: Kombinirovannaya Dvigatelnaya Ustanovka [KDU]) was reconfigured provide full redundancy between two independent propellant manifold loops, supplying oxidizer and fuel to 14 pairs of high-thrust attitude control engines (eight pairs of large and six pairs of small thrusters). With each thruster pair connected to a different manifold, this arrangement significantly enhanced system reliability. Additionally, the number of aft-facing thrusters was doubled, providing crucial backup in case of main engine failure. To complement these hardware modifications, the avionics unit was redesigned, and the EFIR, responsible for tracking propellant consumption, was redesigned to prevent inaccurate readings.
* Improved docking mechanism: The docking system received a backup electric driving mechanism.
* SZI-M reusable black box: A new black box, the SZI-M (Russian: Система Запоминания Информации [СЗИ-М], romanized: Sistema Zapominaniya Informatsii, lit. 'Information Storage System') black box is installed beneath the commander's seat in the descent module. Designed and manufactured in Russia, this device records voice and data throughout the mission. With a capacity of 4 GB and a recording speed of 256 Kb/s, the SZI-M is designed to withstand extreme conditions. It can tolerate falls of 150 m/s and temperatures of 700°C for 30 minutes and is rated for 100,000 overwrite cycles. It can be reused on up to ten missions.
* Power system improvements: To support the increased energy consumption from the improved electronics, a fifth battery with a 155 amp-hour capacity was added, and the cell efficiency on the solar panels improved to 14% (from 12%), and the collective area increased by 1.1 m$^2$ (12 sq ft).
* Additional micro-meteoroid protection: Additional anti-micro-meteoroid shielding was added to the habitation module walls, largely at NASA's request. This measure was designed to safeguard the spacecraft's most vulnerable component against the unlikely but potential threat of a meteoroid or space debris impact.
* Digital camera system: The spacecraft utilizes a digital television camera system based on MPEG-2, replacing the older analog system. This upgrade enables space-to-space RF communication between the spacecraft and the station and reduces interference.

## List of flights

| Mission | Launch Vehicle | Crew | Notes | Duration |
| Completed |||||
| Soyuz MS-01 | Soyuz-FG | Anatoli Ivanishin Takuya Onishi Kathleen Rubins | Delivered Expedition 48/49 crew to ISS. Originally scheduled to ferry the ISS-47/48 crew to ISS, although switched with Soyuz TMA-20M due to delays. | 115 days |
| Soyuz MS-02 | Soyuz-FG | Sergey Ryzhikov Andrey Borisenko Shane Kimbrough | Delivered Expedition 49/50 crew to ISS. Soyuz MS-02 marked the final Soyuz to carry two Russian crew members until Soyuz MS-16 due to Roscosmos deciding to reduce the Russian crew on the ISS. | 173 days |
| Soyuz MS-03 | Soyuz-FG | Oleg Novitsky Thomas Pesquet Peggy Whitson | Delivered Expedition 50/51 crew to ISS. Whitson landed on Soyuz MS-04 following 289 days in space, breaking the record for the longest single spaceflight for a woman. | 196 days |
| Soyuz MS-04 | Soyuz-FG | Fyodor Yurchikhin Jack D. Fischer | Delivered Expedition 51/52 crew to ISS. Crew was reduced to two following a Russian decision to reduce the number of crew members on the Russian Orbital Segment. | 136 days |
| Soyuz MS-05 | Soyuz-FG | Sergey Ryazansky Randolph Bresnik Paolo Nespoli | Delivered Expedition 52/53 crew to ISS. Nespoli became the first European astronaut to fly two ISS long-duration flights and took the record for the second longest amount of time in space for a European. | 139 days |
| Soyuz MS-06 | Soyuz-FG | Alexander Misurkin Mark T. Vande Hei Joseph M. Acaba | Delivered Expedition 53/54 crew to ISS. Misurkin and Vande Hei were originally assigned to Soyuz MS-04, although they were pushed back due a change in the ISS flight program, Acaba was added by NASA later. | 168 days |
| Soyuz MS-07 | Soyuz-FG | Anton Shkaplerov Scott D. Tingle Norishige Kanai | Delivered Expedition 54/55 crew to ISS. The launch was advanced forward in order to avoid it happening during the Christmas holidays, meaning the older two-day rendezvous scheme was needed. | 168 days |
| Soyuz MS-08 | Soyuz-FG | Oleg Artemyev Andrew J. Feustel Richard R. Arnold | Delivered Expedition 55/56 crew to ISS. | 198 days |
| Soyuz MS-09 | Soyuz-FG | Sergey Prokopyev Alexander Gerst Serena Auñón-Chancellor | Delivered Expedition 56/57 crew to ISS. In August 2018, a hole was detected in the spacecraft's orbital module. Two cosmonauts did a spacewalk later in the year to inspect it. | 196 days |
| Soyuz MS-10 | Soyuz-FG | Aleksey Ovchinin Nick Hague | Intended to deliver Expedition 57/58 crew to ISS, flight aborted. Both crew members were reassigned to Soyuz MS-12 and flew six months later on 14 March 2019. | 19m, 41s |
| Soyuz MS-11 | Soyuz-FG | Oleg Kononenko David Saint-Jacques Anne McClain | Delivered Expedition 58/59 crew to ISS, launch was advanced following Soyuz MS-10 in order to avoid de-crewing the ISS. | 204 days |
| Soyuz MS-12 | Soyuz-FG | Aleksey Ovchinin Nick Hague Christina Koch | Delivered Expedition 59/60 crew to ISS. Koch landed on Soyuz MS-13 and spent 328 days in space. Her seat was occupied by Hazza Al Mansouri for landing. | 203 days |
| Soyuz MS-13 | Soyuz-FG | Aleksandr Skvortsov Luca Parmitano Andrew R. Morgan | Delivered Expedition 60/61 crew to ISS. Morgan landed on Soyuz MS-15 following 272 days in space. Christina Koch returned in his seat. Her flight broke Peggy Whitson's record for the longest female spaceflight. | 201 days |
| Soyuz MS-14 | Soyuz-2.1a | — | Uncrewed test flight to validate Soyuz for use on Soyuz 2.1a rocket. The first docking attempt was aborted due to an issue on Poisk. Three days later, the spacecraft successfully docked to Zvezda. | 15 days |
| Soyuz MS-15 | Soyuz-FG | Oleg Skripochka Jessica Meir Hazza Al Mansouri | Delivered Expedition 61/62/EP-19 crew to ISS. Al Mansouri became the first person from the UAE to fly in space. He landed on Soyuz MS-12 after eight days in space as part of Visiting Expedition 19. | 205 days |
| Soyuz MS-16 | Soyuz-2.1a | Anatoli Ivanishin Ivan Vagner Christopher Cassidy | Delivered Expedition 62/63 crew to ISS. Nikolai Tikhonov and Andrei Babkin were originally assigned to the flight, although they were pushed back and replaced by Ivanishin and Vagner due to medical issues. | 195 days |
| Soyuz MS-17 | Soyuz-2.1a | Sergey Ryzhikov Sergey Kud-Sverchkov Kathleen Rubins | Delivered Expedition 63/64 crew to ISS. Marked the first crewed use of the ultra-fast three-hour rendezvous with the ISS previously tested with Progress spacecraft. | 185 days |
| Soyuz MS-18 | Soyuz-2.1a | Oleg Novitsky Pyotr Dubrov Mark T. Vande Hei | Delivered Expedition 64/65 crew to the ISS. Dubrov and Vande Hei were transferred to Expedition 66 for a year mission and returned to Earth on Soyuz MS-19 with Anton Shkaplerov after 355 days in space. | 191 days |
| Soyuz MS-19 | Soyuz-2.1a | Anton Shkaplerov Klim Shipenko Yulia Peresild | Delivered one Russian cosmonaut for Expedition 65/66 and two spaceflight participants for a movie project called The Challenge. The two spaceflight participants returned to Earth on Soyuz MS-18 with Oleg Novitsky after eleven days in space. | 176 days |
| Soyuz MS-20 | Soyuz-2.1a | Alexander Misurkin Yusaku Maezawa Yozo Hirano | Delivered one Russian cosmonaut and two Space Adventures tourists to the ISS for EP-20. The crew returned to Earth after twelve days in space as part of Visiting Expedition 20. | 12 days |
| Soyuz MS-21 | Soyuz-2.1a | Oleg Artemyev Denis Matveev Sergey Korsakov | Delivered three Russian cosmonauts for Expedition 66/67 crew to ISS. | 194 days |
| Soyuz MS-22 | Soyuz-2.1a | Sergey Prokopyev Dmitry Petelin Francisco Rubio | Delivered Expedition 67/68 crew to ISS. All three crew members were transferred to Expedition 69 for a year mission due to a coolant leak and returned to Earth on Soyuz MS-23 after 371 days in space. | 187 days |
| Soyuz MS-23 | Soyuz-2.1a | — | Uncrewed flight to replace the damaged Soyuz MS-22, which returned to Earth uncrewed due to a coolant leak. | 215 days |
| Soyuz MS-24 | Soyuz-2.1a | Oleg Kononenko Nikolai Chub Loral O'Hara | All three crew members were originally planned to fly on Soyuz MS-23, but they were pushed back due to a coolant leak on Soyuz MS-22 that required MS-23 to be launched uncrewed as its replacement. Delivered Expedition 69/70 crew to ISS. Kononenko and Chub were transferred to Expedition 71 for a year mission and returned to Earth on Soyuz MS-25 with Tracy Caldwell Dyson after 374 days in space. | 204 days |
| Soyuz MS-25 | Soyuz-2.1a | Oleg Novitsky Marina Vasilevskaya Tracy Caldwell Dyson | Delivered Expedition 70/71/EP-21 crew to ISS. Novitsky and Vasilevskaya returned to Earth on Soyuz MS-24 with Loral O'Hara after thirteen days in space as part of Visiting Expedition 21. | 184 days |
| In progress |||||
| Soyuz MS-26 | Soyuz-2.1a | Aleksey Ovchinin Ivan Vagner Donald Pettit | Delivered Expedition 71/72 crew to ISS. | ~180 days (planned) |
| Planned |||||
| Soyuz MS-27 | Soyuz-2.1a | Sergey Ryzhikov Alexey Zubritsky Jonny Kim | Planned to rotate future ISS crew. Will deliver Expedition 72/73 crew to ISS. | ~240 days (planned) |
| Soyuz MS-28 | Soyuz-2.1a | Sergey Kud-Sverchkov Sergey Mikayev Christopher Williams | Planned to rotate future ISS crew. Will deliver Expedition 73/74 crew to ISS. | ~240 days (planned) |
| Soyuz MS-29 | Soyuz-2.1a | Pyotr Dubrov Anna Kikina Anil Menon | Planned to rotate future ISS crew. Will deliver Expedition 74/75 crew to ISS. | ~240 days (planned) |