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Soyuz-MS variant

After nearly half a century of orbital missions, Russia's veteran transport spacecraft got another upgrade with the Soyuz-MS version (also know as Series 730). The first mission of the Soyuz MS spacecraft began on July 7, 2016. The spacecraft carried a crew of three to the International Space Station, ISS. Soyuz-MS will supersede the Soyuz-TMA-M variant (Series 700).

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Key new external features of the Soyuz-MS variant.



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The work that never stops

Even before the introduction of the Soyuz TMA-M variant in October 2010, Russian engineers already had a long list of upgrades, which had not made it into then new version, but had to be implemented at a later date. Many of these improvements were dictated not so much by a desire to improve the spacecraft itself, but by the need to replace obsolete components which were going out of production or had to be imported from outside Russia, primarily from Ukraine.

As of 2010, the "wish list" of future upgrades included the following new systems:

  • The Unified Command and Telemetry System (Edinaya Komandno-Telemetricheskaya Sistema, EKTS);
  • The Satellite Navigation Equipment (Apparatura Sputnikovoi Navigatsii, ASN-K);
  • The Laser Velocity and Range Finder (Lazerny Skorostemer-Dalnomer, LSDK);
  • Equipment for Measurement of Parameters of Relative Motion, (Apparatura Izmereniya Parametrov Otnositelnogo Dvizheniya, Kurs-NA);
  • The Direction-finding and Communications System (Sistema Radiosvyazi i Pelengatsii, Rassvet-3BM);
  • A TV system with a digital transmitter, Klest-M;
  • A beefed-up Power Supply System (Sistema Elektropitaniya, SEP);
  • The Descent and Landing Recording System (Sistema Zapisi Informatsii, SZI-P);
  • An upgraded Altimeter Corrector, Kaktus-2V.

In addition, the Soyuz was expected to receive extra thrusters for the rendezvous and orientation system (dvigately prichalivaniya i orientatsii, DPO-B) and the associated avionics unit (Blok Avtomatiki, BA DPO) would be upgraded to reflect that change.

The SSVP docking port aboard Soyuz would receive backup electric motors.

The new and upgraded systems also required a number of changes in associated systems, such as the Motion Control System, SUDN; the Onboard Equipment Control System, SUBK; Communications System, STR; and the Rendezvous Radio System, RTS.

At NASA's request, Russian engineers also developed an Additional Anti-meteoroid Shielding or DPM, for the Habitation Module, BO, of the Soyuz spacecraft.

Finally, various improvements in electricity-generating solar panels were also under consideration.


First flight-worthy Soyuz MS spacecraft during processing in Baikonur.

Development history

According to early plans, most of the extras which could not make into the Soyuz TMA-M upgrade in 2010, would be introduced step-by-step into the future production versions of the TMA-M variant. As of 2010, RKK Energia hoped to complete the upgrades in just two and a half years. (566)

In November of that year, the Interfax news agency quoted the following timeline for three key features of the upgrade program:

At the time, as many as 18 various replacements and design changes were planned for the Soyuz TMA-M spacecraft:

Reasons for upgrade
1st flight
To increase reliability of the electronic generator of propellant consumption signals, EFIR.
Phase I: Upgrade of existing electronics board; Phase II: Design changes in the board.
To beef-up the Power Supply System, SEP, to address increased power demand.
Installation of upgraded solar panels with increased cell area and higher efficiency to increase input from 26 to 35 amperes. Installation of the 5th battery to increase capacity in primary and backup batteries from 350 to 425 amperes per hour.
To increase reliability of the UKT-98 computing unit to exclude errors.
Re-distribution of command-generating semi-conductors among different boards to exclude false connections.
Inability of Lisma-Postarm to supply halogen light bulbs KGZ 12-100 for SMI-4 docking lights.
Replace SMI-4 lights with more advanced SFOK light system.
To improve meteoroid protection of the habitation module per agreement with NASA.
Installation of anti-meteoroid protection on the habitation module.
Need to upgrade the Kaktus-2V landing corrector due to replacement of electronic components.
Phase I: Testing of upgraded corrector in telemetry mode only. Phase II: Functional integration of upgraded Kaktus-2V corrector.
TMA-04M or TMA-05M
The need for more advanced radio communications and direction-finding system.
Replacement of Rassvet-M with Rassvet-3BM unit enabling to determine descent module landing coordinates via GPS/GLONASS system and to transmit this data to mission control via Kospas-Sarsat radio beacons.
Discontinuation of foreign components in the flight data and voice-recording system, SZI.
Development and testing of the upgraded SZI-M system.
The need for higher fault-proof during berthing and pressurization of the docking port.
Introduction of backup electric motors into the docking mechanism.
Discontinuation of angular velocity sensors BDUS-3M production in 2011
Development, manufacturing and testing of new BDUS-3A angular velocity sensors.
Discontinuation of components for the Berthing and Orientation System, BUPO.
Development and testing of the Backup Loop Control Block, BURK, to replace BUPO.
Inability of the obsolete Kvant-V radio-command system to communicate via relay satellites.
Replacement of the Kvant-V system with the EKTS system featuring a phased array antenna and capable of communicating via: (a) ground stations; (b) via satellites.
(a): TMA-10M; (b): TMA-13M
The need to increase reliability in case of failure of any DPO thruster and ensuring crew safety with dual failure of DPO KDU sub-systems, including loss of pressure in one of the propulsion loops.
Re-arrangement of DPO thrusters (to ensure full backup of two propulsion loops).
A planned retirement of the Kama radar stations used for radio-measurements of orbital parameters.
Removal of 38G6 radio-tracking equipment from the navigation system and introduce the ASN-K satellite navigation system.
The need to switch to modern electronic components.
Replacement of the Kurs-A rendezvous system with Kurs-NA within the Motion Control and Navigation System, SUDN.
The requirement to establish the orbital coordinate system, OSK, under manual control without limitations of lighting conditions on Earth and replacement of obsolete avionics.
Replacement of the VSK-4 optical periscope with a TV-based system capable of displaying imagery on the monitor on the cosmonaut's console.
The need to switch from obsolete analog telemetry transmission system to a digital system.
Replacement of the analog Klest-M TV system with a digital transmitter.
To be determined based on experiment
The need to eliminate a possibility for the protrusion of 2ASF1-M-VKA antennas beyond the edge of the docking port in case of its deployment failure before docking with ISS.
Repositioning of the 2ASF1-M-VKA antenna.
To be determined based on experiment


In reality, the effort to upgrade Soyuz TMA-M took six years to complete.

Eventually, most of the planned upgrades were consolidated into a single program for both Progress cargo ships and Soyuz transport vehicles. The project became known as Progress-MS and Soyuz-MS, where MS stood for "modernized systems." As in many previous upgrades, the new features would be tried first on unmanned cargo ships before their certification for use on piloted vehicles. In addition, many of the improvements for the MS series could later be directly incorporated or otherwise benefit the development of the next-generation transport ship, PTK NP.

During the Moscow Air and Space Show in 2011, the head of RKK Energia promised to complete the upgrades for the MS series by the end of 2013 or beginning of 2014. However by 2012, the first launch of the Soyuz-MS spacecraft (No. 731) slipped to the first half of 2015, following the first test flight of the Progress-MS (No. 431) planned in the second half of 2014. Later, various delays eventually pushed the first Soyuz-MS mission into 2016.

During 2013, RKK Energia developed and produced documentation for the Soyuz-MS spacecraft. The company also began manufacturing components and developed blueprints for the integrated electric test stand, KS, for the modified spacecraft. RKK Energia also built a common container for transporting both Progress-MS and Soyuz-MS vehicles and prepared for its testing. The ground test program also called for the development of a dynamic prototype of the Soyuz-MS.

Beginning in 2017, the Soyuz-MS was expected to fully replace the Soyuz TMA-M spacecraft. According to Russian officials, some of the planned upgrades would still be implemented after the launch of the first Soyuz-MS.


An integrated simulator, KS, of the Soyuz-MS spacecraft at RKK Energia's checkout and testing station, KIS.


SUDN flight control and navigation system

Most significant upgrades within the Soyuz-MS series dealt with various components of the Flight Control and Navigation System, SUDN, (from Russian Sistema Upravleniya Dvizheniem i Navigatsii).

ASN-K satellite navigation system

To measure the orbital parameters of the Soyuz and Progress spacecraft, the ships' Flight Control and Navigation System, SUDN, relied on the 38G6 transmitters communicating with six Kama ground stations and Kvant-P ground terminals. By 2010, all these facilities and hardware were marked for retirement and was to be replaced with the ASN-K satellite navigation system, which could simultaneously use the GPS and GLONASS navigation satellites. The system would allow autonomous trajectory measurements by the ship's computers without reliance on ground stations.

According to RKK Energia, which developed the system, the ASN-K consists of four antennas, which are mathematically linked into a single virtual system, allowing uninterrupted navigation measurements independent from a particular orientation of the spacecraft in space. The system provides positioning accuracy within five meters. The ship's attitude (orientation in space) is determined with an accuracy of 0.5 degrees. During a rendezvous, relative coordinates can be determined within one meter and there are hopes to improve the accuracy to just three or four centimeters.

The ASN-K system was first flown on the Progress-M-25M cargo ship in October 2014. Additional tests in support of the ASN-K development were also conducted on the ISS. In April 2016, RKK Energia declared flight testing of ASN-K completed. According to RKK Energia, the new system is five or six times cheaper than its foreign counterparts thanks to the transfer of many functions from hardware to software.

Along with its use on the MS series, RKK Energia promised to install the ASN-K equipment on the next-generation transport ship, PTK.

Kurs-NA rendezvous system

To reach their destination in the Earth's orbit, all spacecraft of the MS series, including Soyuz-MS and Progress-MS were equipped with the new Kurs-NA rendezvous system. It replaced the Kurs-A system, which had been in use since 1986 and employed key components built at the Kiev Radio Plant in Ukraine. To end dependency on foreign suppliers, the production of the new Kurs-NA system was consolidated at the Izhevsk Radio Plant in Russia.

Integrated Propulsion System, KDU

The placement of the 28 attitude control thrusters, DPOs, which are part of the Integrated Propulsion System (Kombinirovannaya Dvigatelnaya Ustanovka, KDU) was rearranged on Soyuz-MS to provide full redundancy between the two independent propellant loops.

Angular velocity sensors

The production of the angular velocity sensors, BDUS-3M (for Blok Datchikov Uglovykh Skorostei), which were used by the flight control system was to be discontinued after 2011. Instead, modified sensors, designated BDUS-3A, were first flight-tested on Progress-MS-01 spacecraft and were then certified for the use on Soyuz-MS.

Motion and Orientation Control Avionics, BUPO

A number of avionics went out of production in the Motion and Orientation Control Unit, BUPO, (from Russian Blok Upravleniya Peremesheniem i Orientatsiei). The latter was replaced with a new digital control unit dubbed Blok Upravleniya Rezervnym Konturom, BURK, which can be translated as the Backup Loop Control Unit. Developed at RKK Energia, the new avionics system was first tested on Progress-MS.

EKTS radio-command system

The existing Kvant-V radio-command system, BRTS, (which stands for Bortovaya Radio-tekhnicheskaya Sistema) developed at AO RKS became obsolete, primarily because it had no ability to communicate via satellites. As a result, Soyuz was able to contact mission control and receive commands only within direct view of ground stations on the Russian territory.

Klest-M TV system

A new digital television system, TVS, which replaced an older Klest (crossbill) analog TV, allows transmission between the transport ship and the space station via onboard radio channels.

According to TASS, the new system uses MPEG-2 encoding and promises to improve TV image quality and make the transmissions less susceptible to interference.

As before, the new television system will provides footage from the inside of the spacecraft as well as images from an external camera in the front of the vehicle, which are available to Soyuz pilots and to mission controllers during docking.

In addition to its original function on Soyuz-MS, the TV system can be integrated into the rendezvous process to facilitate the guidance of the spacecraft toward its target. The Kurs-NA automated rendezvous system was designed to be activated at a distance of around of 150 kilometers from the station and provide coordinates of the station to the Soyuz's flight control system and its crew. Then, at a distance of 80 kilometers, comes the activation of the TV system, which can now beam images between both vehicles participating in the rendezvous, which should help in determining mutual coordinates between the transport ship and its destination. (783)

Location and communications system

The descent module of the Soyuz-MS was equipped with modern Kospas-Sarsat transmitters and GPS/GLONASS navigation systems to help rescue services determine the capsule's position during the descent and after its landing. A special GPS receiver was placed on the hatch of the descent module to enable the capsule to determine its position during the parachute descent. Then, the Kospas-Sarsat transponder within the radio system sends that location to the mission control in Korolev.

Testing of this system was conducted during two missions of the Soyuz spacecraft in 2011. According to ISS Reshetnev, the accuracy of locating the descent module in any weather reached between five and 10 meters.

Information recording system

The upgraded information recording system for Soyuz-MS, designated SZI-M and developed at AO RKS corporation, uses modern, domestically produced electronics. Installed under a pilot seat inside the descent module, SZI-M will act as a "black box," collecting and storing a multitude of flight data, including technical information, physiological parameters of the crew members and voice communications during the descent and landing.

Power supply system

One of the latest challenges in upgrading the Soyuz was the limitation of the ship's power-supply system. Many new systems were coming with an increasing demand for electricity, which available solar panels and storage batteries had an increasingly hard time to provide. According to estimates made around 2010, the power consumption of around eight amperes aboard the Soyuz-T variant introduced at the beginning of the 1980s, was expected to grow to as much as 14.2 amperes on the Soyuz-TMA-M spacecraft (then still in development under a designation Series 700). (780)

DPM, Meteoroid Protection System

Satisfying a long-standing request from NASA, RKK Energia introduced additional shielding to protect the thin walls of the habitation module, BO. It was designed to protect the most vulnerable part of the spacecraft in the unlikely but not impossible event of a meteoroid or space junk strike. According to some reports, the measure could also play a radiation-protection role, even though, the Soyuz flies well below the Earth's radiation belts and, normally, the crew exposure to radiation is insignificant.

According to NASA, the additional protection of the habitation module has been in place since the mission of the Soyuz TMA-04M spacecraft, as projected by the original plan from 2010.

Docking lighting system

By 2010, the Lisma-Postarm company in Saransk, Russia, could no longer guarantee the supply of KGZ 12-100 halogen light bulbs for the SMI-4 lights, which were used to illuminate the target during docking. Instead, the MS series received a new LED-based lighting system, SFOK, which was first tested on the Progress-MS-01 spacecraft.

Cosmonaut launches to move to the 2.1a variant of the Soyuz rocket

One critical step remaining unfulfilled with the introduction of the Soyuz-MS series was the transfer of the spacecraft from the older FG rocket variant to the newer Soyuz-2-1a launcher. The integrated Soyuz-2-1a launch vehicle with the Soyuz-MS spacecraft recieved an industrial designation 371KK35.

The Astra diagnostics system

According to plans approved during 2017, the Soyuz MS-10 spacecraft was supposed to be the first within the Soyuz MS series to be equipped with a new telemetry system, which could be a great help in the investigation of the mishap. The new Astra avionics unit was expected to replace the originally planned Skut-40 system to monitor extremely fast-changing parameters during the ascent to orbit and the separation of the spacecraft from the launch vehicle. The installation of the Astra telemetry system, developed at NPO IT in Korolev, was ordered in the wake of the previous launch accidents with the Progress cargo ships. It was a part of a wider plan to thoroughly analyze flight dynamics of the Soyuz rockets carrying transport ships in order to prevent related accidents. The Progress MS vehicles were also promised to be equipped with the Astra telemetry system starting with the Progress MS-10 mission. The Astra system was also tested onboard the ill-fated Soyuz-2-1b rocket launched from Vostochny on Nov. 28, 2017.

Along with the Astra system, the transport ships would also receive its own network of sensors to measure impacts and vibrations during the flight, however, in order to digest a great deal of data coming from the new measuring network, the ship's flight control system and its software would have to be upgraded accordingly.

Only on Dec. 12, 2018, did AO RKS Corporation, the parent company of NPO IT, confirm that the Astra had indeed been aboard the Soyuz MS-10 spacecraft, but the new telemetry system had never had a chance to operate due to a launch abort. However, the Astra-06 set successfully performed aboard the Soyuz MS-11 spacecraft in December 2018, RKS Corporation said.


Summary of Soyuz MS missions:

Launch date
Landing date
ISS mission
Soyuz MS-01
(No. 731)
2016 July 7
2016 Oct. 30
Expedition 48/49
Anatoly Ivanishin (Roskosmos)
Kate Rubins (NASA)
Takuya Onishi (JAXA)
Soyuz MS-02
(No. 732)
2016 Oct. 19
2017 April 10
Expedition 49/50
Sergey Ryzhikov (Roskosmos)
Andrey Borisenko (Roskosmos)
Shane Kimbrough (NASA)
Soyuz MS-03
(No. 733)
2016 Nov. 17
2017 June 2
Expedition 50/51
Oleg Novitskiy (Roskosmos)
Peggy Whitson (NASA)
Thomas Pesquet (ESA)
Soyuz MS-04
(No. 734)
2017 April 20
2017 Sept. 3
Expedition 51/52
Fyodor Yurchikhin (Roskosmos)
Jack Fischer
Peggy Whitson (NASA, down only)
Soyuz MS-05
(No. 735)
2017 July 28
2017 Dec. 14
Expedition 52/53
Sergei Ryazansky (Roskosmos)
Randolph Bresnik (NASA)
Paolo Nespoli (ESA)
Soyuz MS-06
(No. 736)
2017 Sept. 13
2018 Feb. 28
Expedition 53/54
Aleksandr Misurkin (Roskosmos)
Mark T. Vande Hei (NASA)
Joseph Acaba (NASA)
Soyuz MS-07
(No. 737)
2017 Dec. 17
2018 June 3
Expedition 54/55
Anton Shkaplerov (Roskosmos)
Scott D. Tingle (NASA)
Norishige Kanai (JAXA)
Soyuz MS-08
(No. 738)
2018 March 21
2018 Oct. 4
Expedition 55/56
Oleg Artemyev (Roskosmos)
Drew Feustel (NASA)
Ricky Arnold (NASA)
Soyuz MS-09
(No. 739)
2018 June 6
2018 Dec. 20
Expedition 56/57
Sergei Prokopiev (Roskosmos)
Alexander Gerst (ESA)
Serena Auñón-Chancellor (NASA)
Soyuz MS-10*
(No. 740)
2018 Oct. 11*
2018 Oct. 11*
Expedition 57/58
(Failed to reach orbit)
Aleksei Ovchinin (Roskosmos)
Nick Hague (NASA)
Soyuz MS-11
(No. 741)
2018 Dec. 3
In progress
Expedition 57/58
Oleg Kononenko (Roskosmos)
Anne McClain (NASA)
David Saint-Jacques (CSA)
Soyuz MS-12
(No. 742)
2019 March 14
In progress
Expedition 59/60

Aleksei Ovchinin (Roskosmos)
Christina Hammock-Koch (NASA, up only)
Tyler "Nick" Hague (NASA)
A commercial passenger (UAE, down only)

*Failed launch, emergency landing


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The article and photography by Anatoly Zak; Last update: March 15, 2019

Page editor: Alain Chabot; Last edit: October 6, 2017

All rights reserved


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Click to enlarge. Credit: Roskosmos


Old and new antennas on the Soyuz MS-01 spacecraft during its processing on May 17, 2016. Click to enlarge. Credit: Roskosmos



The habitation module of the Soyuz-MS spacecraft received new anti-meteoroid shielding. Click to enlarge. Credit: Roskosmos /


The EKTS system relies on an S-band phased array mounted on Progress-MS and Soyuz-MS spacecraft for communications with ground control via satellites. Credit: Merkuriy


The AO-753A antenna for the Kurs-NA radio rendezvous system replaced 2AO-VKS and AKR-VKA antennas. Credit: RKS


Astra telemetry system. Credit: AO NPO IT


Soyuz MS-01 blasts off on the morning of July 7, 2016. Click to enlarge. Credit: RKS


Soyuz MS-01 approaches ISS on July 9, 2016. Click to enlarge. Credit: Roskosmos


Launch of the Progress MS-07 spacecraft on Oct. 14, 2017, was an early step in transition of the Soyuz-MS series from the Soyuz-FG to the Soyuz-2-1a rocket variant. Click to enlarge. Credit: Roskosmos


Soyuz MS-09 lifts off on June 6, 2018. Click to enlarge. Credit: ESA