Soyuz launch vehicle

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Soyuz rocket on launch pad.

The Soyuz launch vehicle (Western designation: A-2) is an expendable launch system designed and manufactured by the Korolev Design Bureau in Samara, Russia. As well as being used as the launcher for the manned Soyuz spacecraft, as part of the Soyuz program, it is now used to launch unmanned Progress supply spacecraft to the International Space Station and commercial launches marketed and operated by TsSKB-Progress and the Starsem company. There were 11 Soyuz launches in 2001 and 9 in 2002. Currently Soyuz vehicles are launched from the Baikonur Cosmodrome in Kazakhstan and the Plesetsk Cosmodrome in northwest Russia. Starting 2008 Soyuz launch vehicles will also be launched from the Centre Spatial Guyanais in French Guiana. Soyuz rockets are fueled with kerosene, but the Soyuz-U rocket used a variant called Syntin.

[edit] History

The launcher was introduced in 1966, deriving from the Vostok launcher, which in turn was based on the 8K74 or R-7a intercontinental ballistic missile. It was initially a three-stage rocket with a Block I upper stage. Later a Molniya variant was produced by adding a fourth stage, allowing it to reach the highly elliptical molniya orbit. A later variant was the Soyuz-U.

The production of Soyuz launchers reached a peak of 60 per year in the early 1980s. It has become the world's most used space launcher, flying over 850 times, far more than any other rocket. It is a very old basic design, but is notable for low cost and very high reliability, both of which appeal to commercial clients.

Soyuz rocket engines

In the early 1990s plans were made for a redesigned Soyuz with a Fregat upper stage. The Fregat engine was developed by NPO Lavochkin from the propulsion module of its Phobos interplanetary probes. Although endorsed by the Russian Space Agency and the Russian Ministry of Defence in 1993 and designated "Rus" as a Russification and modernisation of Soyuz, and later renamed Soyuz 2, a funding shortage prevented implementation of the plan. The creation of Starsem in July 1996 provided new funding for the creation of a less ambitious variant, the Soyuz-Fregat or Soyuz U/Fregat. This consisted of a slightly modified Soyuz U combined with the Fregat upper stage, with a capacity of up to 1,350 kg to geostationary transfer orbit. In April 1997, Starsem obtained a contract from the European Space Agency to launch two pairs of Cluster 2 plasma science satellites using the Soyuz-Fregat. Before the introduction of this new model, Starsem launched 24 satellites of the Globalstar constellation in 6 launches with a restartable Ikar upper stage, between September 22, 1999 and November 22, 1999. After successful test flights of Soyuz-Fregat on February 9, 2000 and March 20, 2000, the Cluster 2 satellites were launched on July 16, 2000 and August 9, 2000. Another Soyuz-Fregat launched the ESA's Mars Express probe from Baikonur in June 2003. Now the Soyuz-Fregat launcher is used by Starsem for commercial payloads. It is due to be replaced by the new launcher, now named Soyuz/ST (or Soyuz-2), which will have a new digital guidance system and a strongly modified third stage with a new engine. The first development version of Soyuz-2 called Soyuz-2-1a, which is already equipped with the digital guidance system and a modified third stage, but is still propelled by an old engine, started on November 4, 2004 from Plesetsk on a suborbital test flight. The fully modified launcher (version Soyuz-2-1b) is planned to fly first in the spring of 2006 from the Baikonur Cosmodrome.

A long string of successful Soyuz launches was broken on October 15, 2002 when the unmanned Soyuz U launch of the Photon-M satellite from Plesetsk fell back near the launch pad and exploded 29 seconds after lift-off. One person was killed and eight injured. Another failure occurred on June 21, 2005, during a Molniya military communications satellite launch from the Plesetsk launch site, which used a four-stage version of the Soyuz rocket called Molniya-M. The flight ended six minutes after the launch because of a failure of the third stage engine or an unfulfilled order to separate the second and third stages. The rocket's second and third stages, which are identical to the Soyuz, and its payload (a Molniya-3K satellite) crashed in the Uvatski region of Tyumen (Siberia) [1]. However, under this designation of Molniya-M launcher, the other 274 unmanned Soyuz launches have been successful.

Between February 1, 2003 and July 26, 2005 with the grounding of the US Space Shuttle fleet, Soyuz was the only means of transportation to and from the International Space Station. This included the transfer of supplies, via Progress spacecraft, and crew changeovers.

Soyuz (in the new version Soyuz/ST) is also planned to be brought into ESA service in 2007 under a Russo-European joint venture. It is planned to build a new launch pad in French Guiana.

[edit] Stages

Soyuz rocket assembly - the first and second stages are mated together and can be seen in the background, third stage is in the lower left corner of the image. Soyuz spaceship, covered by its launch shroud, is in the lower right corner

[edit] First stage

The first stage of Soyuz rockets consists of four identical conical liquid booster rockets, strapped to the second stage core. Each booster has a single rocket motor (four combustion chambers, two vernier combustion chambers, one set of turbopumps).

Statistics (each of 4 boosters)

• Gross mass: 44.5 t (98,100 lbm)
• Propellant: 39.2 t (86,400 lbm)
• Dry mass: 3,784 kg (8,342 lbm)
• Diameter: 2.68 m (8 ft 10 in)
• Length: 19.6 m (64 ft 4 in)
• Engines:
  • Soyuz and Soyuz-U models
    • RD-107
      • Thrust 813 kN (183 klb_f) at liftoff
      • Thrust 991 kN (223 klb_f) in vacuum
      • Specific impulse 245 kgf·s/kg (2.40 kN·s/kg) at liftoff
      • Specific impulse 310 kgf·s/kg (3.04 kN·s/kg) in vacuum
      • Chamber pressure 5.85 MPa (848 psi)
  • Soyuz-ST models
    • RD-117
      • Thrust 838 kN (188 klb_f) at liftoff
      • Thrust 1021 kN (230 klb_f) in vacuum
      • Specific impulse 245 kgf·s/kg (2.40 kN·s/kg) at liftoff (est)
      • Specific impulse 310 kgf·s/kg (3.04 kN·s/kg) in vacuum (est)
      • Chamber pressure 5.85 MPa (848 psi)

[edit] Second stage

The second stage of the Soyuz booster is a single, generally cylindrical stage with one motor (four combustion chambers, four vernier combustion chambers, one set of turbopumps) at the base. The stage gets somewhat wider near the top.

• Gross mass: 105.4 t (232,400 lbm)
• Propellant: 95.4 t (210,000 lbm)
• Propellant (Soyuz-U2 with Syntin propellant): 96.4 t (212,000 lbm)
• Dry mass: 6,875 kg (15,160 lbm)
• Length: 28 m (91 ft 10 in)
• Diameter: 2.95 m (9 ft 8 in)
• Engines:
  • Soyuz and Soyuz-U models
    • RD-108
      • Thrust 779 kN (175 klb_f) at liftoff
      • Thrust 997 kN (224 klb_f) in vacuum
      • Specific impulse 264 kgf·s/kg (2.59 kN·s/kg) at liftoff
      • Specific impulse 311 kgf·s/kg (3.05 kN·s/kg) in vacuum
      • Chamber pressure 5.1 MPa (740 psi)
  • Soyuz-U2 model with Syntin fuel
    • RD-108
      • Thrust 811 kN (182 klb_f) at liftoff
      • Thrust 1009 kN (227 klb_f) in vacuum
      • Specific impulse 264 kgf·s/kg (2.59 kN·s/kg) at liftoff
      • Specific impulse 311 kgf·s/kg (3.05 kN·s/kg) in vacuum
      • Chamber pressure 5.1 MPa (740 psi)
  • Soyuz-ST models
    • RD-118
      • Thrust 792 kN (178 klb_f) at liftoff
      • Thrust 990 kN (222 klb_f) in vacuum
      • Specific impulse 264 kgf·s/kg (2.59 kN·s/kg) at liftoff (est)
      • Specific impulse 311 kgf·s/kg (3.05 kN·s/kg) in vacuum (est)
      • Chamber pressure 5.85 MPa (848 psi)

[edit] Third stage

There are two variant upper stages in use, the Block I and Improved Block-I (used in Soyuz-2-1b).

• Gross mass: 25.2 t (55,600 lbm)
• Propellant: 21.4-22.9 t (47,200–50,500 lbm)
• Dry mass: 2355 kg (5190 lbm)
• Length: 6.7 m (22 ft 0 in)
• Diameter: 2.66 m (8 ft 9 in)
• Engine:
  • Block I
    • RD-0110
    • Thrust 298 kN (67.0 klb_f)
    • Specific impulse 330 kgf·s/kg (3.24 kN·s/kg)
    • Chamber pressure 6.8 MPa (986 psi)
  • Improved Block I
    • RD-0124
    • Thrust 294 kN (66 klb_f)
    • Specific impulse 359 kgf·s/kg (3.52 kN·s/kg)
    • Chamber pressure 16.2 MPa (2350 psi)

[edit] External links

Wikimedia Commons has media related to:

Soyuz (rocket)

• R-7 missile family page
• Starsem
• Soyuz launch log at Starsem
• Soyuz U/Fregat

[edit] References

• International Reference Guide to Space Launch Systems, Third Edition, Iaskowitz, Hopkins, and Hopkins ed., 1999, Reston, Virginia, AIAA Publications. ISBN 1-56347-353-4