Development The first Soyuz launcher was introduced in 1966. It was derived from the earlier
Vostok launcher, which in turn had been based on the
R-7 Semyorka, the world's first
intercontinental ballistic missile. The Soyuz used a three-stage design with the Block I third stage. Its first four test flights ended in failure, but subsequent missions achieved success. A four-stage variant, the
Molniya, was developed by adding an additional upper stage, enabling launches into highly elliptical
Molniya orbits. A later evolution, the
Soyuz-U, became the workhorse of the family. During the Cold War, the exact Soviet model designations were not publicly available. In the West, the
United States Department of Defense referred to the Soyuz launcher as SL-4, while
Charles Sheldon of the
Library of Congress devised the A-2 designation. Both systems were eventually abandoned as more accurate information became available. Production of Soyuz rockets peaked at about 60 units per year in the early 1980s. By the 21st century, the Soyuz had become the world's most frequently used space launcher, with more than 1,700 flights. Despite its age, the family has remained in service due to its comparatively low cost, high reliability, and proven performance.
Soyuz / Fregat erected at the
Baikonur Cosmodrome launch pad 1/5 (nicknamed ''
Gagarin's Start'') ahead of
Soyuz TMA-13 in October 2008. 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
Roscosmos and the
Russian Ministry of Defence in 1993 and designated "Rus" as a Russification and modernization 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 to
geostationary transfer orbit. In April 1997,
Starsem obtained a contract from the
European Space Agency (ESA) to launch two pairs of
Cluster II 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 22 September 1999 and 22 November 1999. After successful test flights of Soyuz-Fregat on 9 February 2000 and 20 March 2000, the
Cluster II satellites were launched on 16 July 2000 and 9 August 2000. Another Soyuz-Fregat launched the ESA's
Mars Express probe from Baikonur in June 2003.
ISS crew transport Between 1 February 2003 and 26 July 2005 with the grounding of the United States
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. After the retirement of the Space Shuttle fleet in 2011, the
United States space program was without any means to take astronauts into orbit, and
NASA was dependent on the Soyuz to send crew into space until 2020. NASA resumed crewed flights from the United States in 2020 through the
Commercial Crew Development program.
Recent incidents A long streak of successful Soyuz launches was broken on 15 October 2002 when the uncrewed
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 from the ground crew was killed and eight were injured. Another failure occurred on 21 June 2005, during a
Molniya military communications satellite launch from the Plesetsk launch site, which used a four-stage version of the 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
Uvatsky region of
Tyumen (
Siberia). On 24 August 2011, an uncrewed Soyuz-U carrying cargo to the International Space Station crashed, failing to reach orbit. On 23 December 2011, a Soyuz-2.1b launching a
Meridian 5 military communications satellite failed in the 7th minute of launch because of an anomaly in the third stage. On 11 October 2018, the
Soyuz MS-10 mission to the
International Space Station failed to reach orbit after an issue with the main booster. Four payload mounted solid rocket jettison motors were used to pull the Soyuz spacecraft away from the malfunctioning rocket, as the main
launch abort system tower had been jettisoned.The two crew,
Aleksey Ovchinin and
Nick Hague, followed a ballistic trajectory and landed safely over 400 km downrange from the
Baikonur Cosmodrome.
Soyuz 2 ready to launch (2007) The venerable Soyuz-U launcher was gradually replaced by a new version, named
Soyuz 2, which has a new digital guidance system and a highly modified third stage with a new engine. The first development version of Soyuz 2 called
Soyuz 2.1a, which is equipped with the digital guidance system, but is still propelled by an old third stage engine, started on 4 November 2004 from
Plesetsk on a suborbital test flight, followed by an orbital flight on 23 October 2006 from Baikonur. The fully modified launcher (version
Soyuz 2.1b) flew first on 27 December 2006 with the
CoRoT satellite from the
Baikonur Cosmodrome. On 19 January 2005, the
European Space Agency (ESA) and the
Roscosmos agreed to launch Soyuz ST rockets from the
Guiana Space Centre. The equatorial launch site allows the Soyuz to deliver 2.7 to 4.9 tonnes into
Sun-synchronous orbit, depending on the third-stage engine used. Construction of a new pad started in 2005 and was completed in April 2011. The pad used vertical loading common at
French Guiana, unlike the horizontal loading used at the
Baikonur Cosmodrome. A simulated launch was conducted in early May 2011. The first operational launch happened on 21 October 2011, bearing the first two satellites in
Galileo global positioning system. The
Soyuz-U and
Soyuz-FG rockets were gradually replaced by
Soyuz 2 from 2014 until 2019. Soyuz-U was retired in 2017, while Soyuz-FG carried
astronaut crews to the
ISS until September 2019 (final flight,
Soyuz MS-15, on 25 September 2019). Image:RocketLaunch2018-08.jpg|Soyuz-2.1b (2018) Image:"Soyuz" launch vehicles model series on MAKS-2021.jpg|From left: Soyuz-2.1v, Soyuz-2.1a, Soyuz-2.1b and
Soyuz-5) == Variants ==