Soyuz (rocket family)

• 1. Introduction

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  Soyuz holds the record for the most launches in the history of spaceflight. That single fact, buried in technical documents and launch logs, is extraordinary when you consider what it means: one rocket family, born in the Soviet Union during the Cold War, has put more hardware into orbit than any other machine ever built. How does a design conceived in the 1960s outlast the Space Shuttle, survive the collapse of the Soviet Union, and end up as the only certified vehicle capable of carrying astronauts to the International Space Station for nearly a decade? The answers lie in the Soyuz's peculiar combination of political origins, engineering pragmatism, and a lineage that traces back to the world's first intercontinental ballistic missile. This is the story of a rocket that was never supposed to be permanent, and has never been replaced.

• 2. From Missile to Launcher

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  The R-7 Semyorka, the world's first intercontinental ballistic missile, is the ancestor of almost every Soyuz rocket ever flown. That heritage is not incidental. The Vostok launcher came first, derived directly from the R-7, and it put Yuri Gagarin into orbit. Soyuz came next in 1966, derived from Vostok, adding a Block I third stage to reach a three-stage configuration. The first four test flights of the new design all ended in failure. Success followed, and the rocket settled into a rhythm that would carry it for decades. During the Cold War, the Soviets did not publish their own model designations for the launcher. The United States Department of Defense called it SL-4. Charles Sheldon of the Library of Congress devised a separate designation, A-2. Both systems were eventually discarded as better information reached the West. Production of Soyuz rockets peaked at roughly 60 units per year in the early 1980s, a manufacturing tempo that reflected both Soviet ambition and the scale of the state industrial machine behind the design.

• 3. The Record Holder

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  More than 1,700 flights had accumulated by the time the Soyuz entered the 21st century, making it the world's most frequently used space launcher. The Soyuz-U variant accounts for a significant portion of that total; the source records 786 launches for the Soyuz-U alone, making it the single most launched carrier rocket ever built. Its maiden flight was on the 18th of May 1973, and it flew its final mission on the 22nd of February 2017. The family's dominance was not built on any one spectacular achievement but on a steady accumulation of missions: crewed spacecraft, reconnaissance satellites, cargo runs to Mir, and eventually to the International Space Station. Despite the volume of flights, the majority of Soyuz launches have been dedicated not to crewed missions but to deploying satellites for both governmental and commercial customers. The association with crewed spaceflight came from the recurring Soyuz spacecraft launches that gave the rocket its name in the public mind.

• 4. The Nine-Year Window

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  Between the 1st of February 2003 and the 26th of July 2005, after the Space Shuttle fleet was grounded following the Columbia disaster, Soyuz was the sole means of transportation to and from the International Space Station. That dependency continued in a different form after the Shuttle was retired in 2011. NASA found itself without any domestic vehicle for crewed spaceflight and paid Russia to fly its astronauts on Soyuz until 2020, when SpaceX's Crew Dragon completed its first crewed mission through the Commercial Crew Development program. During those years, Soyuz carried not only astronauts but also supplies via the uncrewed Progress cargo spacecraft, which shares its launch system with the crewed variant. The political and commercial implications of that period were considerable; a launcher designed for Soviet military and scientific purposes had become the indispensable lifeline of the entire world's human spaceflight program.

• 5. Incidents and Resilience

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  On the 15th of October 2002, an uncrewed Soyuz-U carrying the Photon-M satellite lifted off from Plesetsk, fell back near the launch pad, and exploded 29 seconds after lift-off. One ground crew member was killed and eight were injured. On the 24th of August 2011, a second uncrewed Soyuz-U carrying cargo to the ISS crashed and failed to reach orbit. The most dramatic incident came on the 11th of October 2018, when the crewed Soyuz MS-10 mission suffered a booster failure shortly after launch. The main launch abort system tower had already been jettisoned, so four payload-mounted solid rocket jettison motors pulled the Soyuz spacecraft away from the malfunctioning rocket. Aleksey Ovchinin and Nick Hague followed a ballistic trajectory and landed safely more than 400 km downrange from the Baikonur Cosmodrome. The crew survived because of a launch abort system designed into the Soyuz spacecraft rather than any feature of the rocket itself.

• 6. Modernization and New Markets

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  Plans for a redesigned Soyuz with a Fregat upper stage began in the early 1990s. The Fregat engine was developed by NPO Lavochkin from the propulsion module of its Phobos interplanetary probes. Roscosmos and the Russian Ministry of Defence endorsed the plan in 1993 and initially called it "Rus," later renamed Soyuz-2, but funding shortages blocked implementation. The creation of Starsem in July 1996 brought new commercial financing and produced a more modest variant, the Soyuz-U/Fregat, capable of delivering up to 1,350 kg to geostationary transfer orbit. Starsem secured a contract from the European Space Agency in April 1997 to launch the Cluster II plasma science satellites. After successful test flights on the 9th of February 2000 and the 20th of March 2000, the two pairs of Cluster II satellites flew on the 16th of July 2000 and the 9th of August 2000. The ESA's Mars Express probe followed from Baikonur in June 2003. On the 19th of January 2005, ESA and Roscosmos agreed to launch Soyuz ST rockets from the Guiana Space Centre in French Guiana, with an equatorial site capable of delivering 2.7 to 4.9 tonnes into Sun-synchronous orbit. The first operational launch from Kourou took place on the 21st of October 2011, carrying the first two satellites of Europe's Galileo global positioning system.

• 7. Engineering the Launch

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  Soyuz rockets are assembled horizontally in the Assembly and Testing Building, then transported to the launch site lying flat and raised into position. That horizontal approach differs sharply from the vertical assembly of rockets like the Saturn V, and it is one of the primary reasons the Soyuz costs less to prepare. A vertically assembled rocket requires a windproof high-rise hangar; the Soviet designers judged such a structure financially unfeasible given the failing economy of the era in which the rocket was designed. At the launch pad, the entire rocket is suspended by load-bearing mechanisms on the strap-on boosters, which in turn push against the central core. When the engines ignite, electrically initiated pyrotechnic flares mounted on birch poles light the propellants at approximately T-20 seconds. After liftoff, the strap-on boosters fall away cleanly, and in clear weather, observers on the ground can see a pattern called the Korolev cross formed by the four falling boosters. The Soyuz-2.1v, the most recent variant of the core rocket family, introduced a completely new first-stage design using the NK-33 engine originally developed for the Soviet N1 Moon launcher, and it flew its maiden flight on the 28th of December 2013.