Encyclopedia Astronautica
Soyuz ST / Fregat ST


Uprated Soyuz booster designed for commercial customers. Upgraded engines, modern avionics, reduced non-Russian content. Uses Fregat upper stage.

Also known as the Soyuz 2, it was a modernisation of the Soyuz launcher that increased general performance. The basic launch vehicle design remained the same. Changes were limited to:

  • The first and second stage engines featured improved performance with new injectors and mixture ratio.
  • The third stage engine performance was increased.
  • The launch vehicle was equipped with a new control system allowing in-flight orbital plane change (whereas all earlier R-7 derived vehicles flew a fixed trajectory, with the launch table rotated before launch to the appropriate azimuth).
  • A new digital telemetry system provided for launch vehicle monitoring.
  • A new, larger-diameter fairing (3.65 meters in diameter) was used.

The standard fourth stage was the Fregat orbital module.

The Fregat upper stage has a flight-proved propulsion subsystem that is based on a single-chamber Lavochkin engine. Four clusters of three 50-N hydrazine thrusters provide attitude control. The Fregat propulsion system powered the Fobos probe to Mars, and the main engine was fitted on nearly 30 interplanetary spacecraft. During its numerous missions, the engine demonstrated the highest reliability under extreme conditions, exceeding technical specifications. This application of proven, in-production hardware ensures high reliability and lower cost for the Fregat upper stage. Fregat operates on UDMH fuel and N2O4 oxidizer, and has a liftoff mass of up to 6,535 kg. The weight at burnout is 950-1,100 kg.. Vacuum thrust is 19.6 kN., and burn time is up to 877 sec. The engine can be restarted as many as 20 times.

LEO Payload: 5,500 kg (12,100 lb) to a 450 km orbit at 51.80 degrees. Payload: 4,500 kg (9,900 lb) to a 800 km SSO. Launch Price $: 35.000 million in 1999 dollars.

Stage Data - Soyuz ST / Fregat ST

  • Stage 0. 4 x Soyuz ST-0. Gross Mass: 44,400 kg (97,800 lb). Empty Mass: 3,810 kg (8,390 lb). Thrust (vac): 1,021.097 kN (229,552 lbf). Isp: 310 sec. Burn time: 120 sec. Isp(sl): 264 sec. Diameter: 2.68 m (8.79 ft). Span: 2.68 m (8.79 ft). Length: 19.60 m (64.30 ft). Propellants: Lox/Kerosene. No Engines: 1. Engine: RD-117. Status: In production. Comments: Gross mass includes 1190 kg of hydrogen peroxide and 280 kg of liquid nitrogen expended during ascent but not contributing to propulsion.
  • Stage 1. 1 x Soyuz ST-1. Gross Mass: 105,400 kg (232,300 lb). Empty Mass: 6,875 kg (15,156 lb). Thrust (vac): 999.601 kN (224,719 lbf). Isp: 311 sec. Burn time: 286 sec. Isp(sl): 245 sec. Diameter: 2.95 m (9.67 ft). Span: 2.95 m (9.67 ft). Length: 27.80 m (91.20 ft). Propellants: Lox/Kerosene. No Engines: 1. Engine: RD-118. Status: In production. Comments: Gross mass includes 2600 kg of hydrogen peroxide and 520 kg of liquid nitrogen expended during ascent but not contributing to propulsion.
  • Stage 2. 1 x Soyuz ST-2. Gross Mass: 25,200 kg (55,500 lb). Empty Mass: 2,355 kg (5,191 lb). Thrust (vac): 294.000 kN (66,093 lbf). Isp: 359 sec. Burn time: 300 sec. Diameter: 2.66 m (8.72 ft). Span: 2.66 m (8.72 ft). Length: 6.74 m (22.11 ft). Propellants: Lox/Kerosene. No Engines: 1. Engine: RD-0124. Status: In production.
  • Stage 3. 1 x Fregat. Gross Mass: 6,535 kg (14,407 lb). Empty Mass: 1,100 kg (2,400 lb). Thrust (vac): 19.600 kN (4,406 lbf). Isp: 327 sec. Burn time: 877 sec. Diameter: 3.35 m (10.99 ft). Span: 3.35 m (10.99 ft). Length: 1.50 m (4.90 ft). Propellants: N2O4/UDMH. No Engines: 1. Engine: S5.92. Status: Out of Production. Comments: Upper stage developed from propulsion bus for Lavochkin lunar and planetary probes (Luna Ye-8, Mars M1, Fobos 1F). 20 restarts.

AKA: SL-4; Sapwood; A-2.
Status: In production.
Gross mass: 305,000 kg (672,000 lb).
Payload: 5,500 kg (12,100 lb).
Height: 46.10 m (151.20 ft).
Diameter: 2.95 m (9.67 ft).
Thrust: 4,144.70 kN (931,766 lbf).
Apogee: 450 km (270 mi).
First Launch: 2009.09.17.
Last Launch: 2010.11.02.
Number: 8 .

More... - Chronology...


Associated Countries
Associated Spacecraft
  • Meteor-M New-generation Russian weather satellite, successor to the Meteor-3M, with new electronics and designed for launch by the Soyuz ST launch vehicle rather than the discontinued Tsiklon-3 and non-Russian Zenit-2. First launched in 2009. More...

Associated Engines
  • S5.92 Isayev N2O4/UDMH rocket engine. 19.6 kN. Phobos propulsion module, later adapted as Fregat upper stage. In production. Isp=327s. Gas generator cycle. Nominal and low-thrust thrust levels. More...

See also
  • R-7 The world's first ICBM became the most often used and most reliable launch vehicle in history. The original core+four strap-on booster missile had a small third stage added to produce the Vostok launch vehicle, with a payload of 5 metric tons. Addition of a larger third stage produced the Voskhod/Soyuz vehicle, with a payload over 6 metric tons. Using this with a fourth stage, the resulting Molniya booster placed communications satellites and early lunar and planetary probes in higher energy trajectories. By the year 2000 over 1,628 had been launched with an unmatched success rate of 97.5% for production models. Improved models providing commercial launch services for international customers entered service in the new millenium, and a new launch pad at Kourou was to be inaugurated in 2011. It appeared that the R-7 could easily still be in service 70 years after its first launch. More...

Associated Manufacturers and Agencies
  • Korolev Russian manufacturer of rockets, spacecraft, and rocket engines. Korolev Design Bureau, Kaliningrad, Russia. More...

Associated Launch Sites
  • Baikonur Russia's largest cosmodrome, the only one used for manned launches and with facilities for the larger Proton, N1, and Energia launch vehicles. The spaceport ended up on foreign soil after the break-up of Soviet Union. The official designations NIIP-5 and GIK-5 are used in official Soviet histories. It was also universally referred to as Tyuratam by both Soviet military staff and engineers, and the US intelligence agencies. Since the dissolution of the Soviet Union the Russian Federation has insisted on continued use of the old Soviet 'public' name of Baikonur. In its Kazakh (Kazak) version this is rendered Baykonur. More...
  • Plesetsk Plesetsk was the Soviet Union's northern cosmodrome, used for polar orbit launches of mainly military satellites, and was at one time the busiest launch centre in the world. The collapse of the Soviet Union put the main launch site of Baikonur in Kazakh territory. It now seems that once the Proton rocket is retired, Baikonur will be abandoned and Plesetsk will be Russia's primary launch centre. Upgrades to existing launch facilities will allow advanced versions of the Soyuz rocket and the new Angara launch vehicle to be launched from Plesetsk. Plesetsk's major drawback was the lower net payload in geosynchronous orbit from a northern latitude launch site. However Russia is planning to remove the disadvantage by looping geosynchronous satellites around the moon, using lunar gravity to make the necessary orbital plane change. More...

Associated Stages
  • Fregat N2O4/UDMH propellant rocket stage. Loaded/empty mass 6,535/1,100 kg. Thrust 19.60 kN. Vacuum specific impulse 327 seconds. Upper stage developed from propulsion bus for Lavochkin lunar and planetary probes (Luna Ye-8, Mars M1, Fobos 1F). 20 restarts. More...
  • Soyuz ST-0 Lox/Kerosene propellant rocket stage. Loaded/empty mass 44,400/3,810 kg. Thrust 1,021.10 kN. Vacuum specific impulse 310 seconds. Gross mass includes 1190 kg of hydrogen peroxide and 280 kg of liquid nitrogen expended during ascent but not contributing to propulsion. More...
  • Soyuz ST-1 Lox/Kerosene propellant rocket stage. Loaded/empty mass 105,400/6,875 kg. Thrust 999.60 kN. Vacuum specific impulse 311 seconds. Gross mass includes 2600 kg of hydrogen peroxide and 520 kg of liquid nitrogen expended during ascent but not contributing to propulsion. More...
  • Soyuz ST-2 Lox/Kerosene propellant rocket stage. Loaded/empty mass 25,200/2,355 kg. Thrust 294.00 kN. Vacuum specific impulse 359 seconds. More...

Soyuz ST / Fregat ST Chronology


2009 May 21 - . 21:53 GMT - . Launch Site: Plesetsk. Launch Complex: Plesetsk LC43/4. LV Family: R-7. Launch Vehicle: Soyuz ST / Fregat ST. LV Configuration: Soyuz-2-1a/Fregat.
  • Meridian 2 - . Nation: Russia. Agency: KVR. Spacecraft: Meridian. USAF Sat Cat: 35008 . COSPAR: 2009-029A. Apogee: 36,423 km (22,632 mi). Perigee: 328 km (203 mi). Inclination: 62.9000 deg. Period: 646.00 min. Summary: Secon Meridian communications satellite. Third stage cut off early. Fregat upper stage ran out of fuel during second burn, leaving satellite in useless orbit..

2009 September 17 - . 15:55 GMT - . Launch Site: Baikonur. Launch Complex: Baikonur LC31. LV Family: R-7. Launch Vehicle: Soyuz ST / Fregat ST. LV Configuration: Soyuz-2-1b/Fregat.
  • Sumbandila - . Mass: 81 kg (178 lb). Nation: Russia. Agency: RKA. Class: Technology. Type: Technology satellite. USAF Sat Cat: 35870 . COSPAR: 2009-049F. Apogee: 505 km (313 mi). Perigee: 501 km (311 mi). Inclination: 97.3000 deg. Period: 94.70 min. Summary: South African imaging satellite with a ground resolution of 6.25 m..

2009 September 17 - . 15:55 GMT - . Launch Site: Baikonur. Launch Complex: Baikonur LC31. LV Family: R-7. Launch Vehicle: Soyuz ST / Fregat ST. LV Configuration: Soyuz-2-1b/Fregat.
  • Tatyana-2 - . Mass: 90 kg (198 lb). Nation: Russia. Class: Science. Type: Science satellite. COSPAR: 2009-049. Summary: Space physics research satellite built by students from Moscow State University..
  • Sterkh 12L - . Nation: Russia. Class: Surveillance. Type: Civilian surveillance radar satellite. Spacecraft: Parus. COSPAR: 2009-049. Summary: Second dedicated Sterkh search-and-rescue satellite..
  • UGATUSAT - . Mass: 35 kg (77 lb). Nation: Russia. Class: Surveillance. Type: Surveillance satellite. COSPAR: 2009-049. Summary: Remote sensing satellite built by the Ufa State Aviation Technical University..

2009 September 17 - . 15:55 GMT - . Launch Site: Baikonur. Launch Complex: Baikonur LC31. LV Family: R-7. Launch Vehicle: Soyuz ST / Fregat ST. LV Configuration: Soyuz-2-1b/Fregat.
  • IRIS - . Nation: Russia. Agency: RKA. Class: Technology. Type: Technology satellite. USAF Sat Cat: 35867 . COSPAR: 2009-049C. Apogee: 502 km (311 mi). Perigee: 490 km (300 mi). Inclination: 97.3000 deg. Period: 94.50 min. Summary: Inflatable structure technology test - two inflatable masts carrying dummy solar arrays..
  • BLITS - . Mass: 7.00 kg (15.40 lb). Nation: Russia. Agency: RKA. Class: Earth. Type: Earth resources satellite. USAF Sat Cat: 35871 . COSPAR: 2009-049G. Apogee: 822 km (510 mi). Perigee: 818 km (508 mi). Inclination: 98.8000 deg. Period: 101.30 min. Summary: Spherical glass lens for laser geodesy, built by the NII for Precision Instruments (NIIPP), Moscow..
  • Meteor-M - . Mass: 2,700 kg (5,900 lb). Nation: Russia. Agency: RKA. Class: Earth. Type: Weather satellite. Spacecraft: Meteor-M. USAF Sat Cat: 35865 . COSPAR: 2009-049A. Apogee: 820 km (500 mi). Perigee: 818 km (508 mi). Inclination: 98.8000 deg. Period: 101.30 min. First Meteor-M satellite. This replaced the Meteor-3M satellite, with new generation weather instruments. Plagued with problems: the infrared sensor cooling broke down, an antenna did not deploy properly, camera mirrors were degraded by vibration, imagery was not delivered in a usable rectified format.

2010 October 19 - . 17:10 GMT - . Launch Site: Baikonur. Launch Complex: Baikonur LC31. LV Family: R-7. Launch Vehicle: Soyuz ST / Fregat ST. LV Configuration: Soyuz-2-1a/Fregat.
  • Globalstar M073 - . Payload: Globalstar-2 M073. Mass: 700 kg (1,540 lb). Nation: USA. Agency: RKA. Class: Communications. Type: Communications satellite. Spacecraft: Proteus. USAF Sat Cat: 37193 . COSPAR: 2010-054F. Apogee: 1,004 km (623 mi). Perigee: 955 km (593 mi). Inclination: 52.0000 deg. Period: 104.70 min.

2010 November 2 - . 00:59 GMT - . Launch Site: Plesetsk. Launch Complex: Plesetsk LC43/3. LV Family: R-7. Launch Vehicle: Soyuz ST / Fregat ST. LV Configuration: Soyuz-2-1a/Fregat.
  • Meridian 3 - . Nation: Russia. Class: Communications. Type: Communications satellite. Spacecraft: Meridian. USAF Sat Cat: 37212 . COSPAR: 2010-058A. Apogee: 39,395 km (24,478 mi). Perigee: 957 km (594 mi). Inclination: 62.8000 deg. Period: 717.70 min. Summary: Third military communications satellite in this series..

Home - Browse - Contact
© / Conditions for Use