Soyuz2 (, GRAU index: 14A14) is a series of Russian expendable medium-lift launch vehicles and the seventh major iteration of the Soyuz rocket family. Compared to its predecessors, Soyuz-2 features significant upgrades, including improved engines and a digital flight control system that enables launches from fixed platforms and supports larger payload fairings.

Developed and produced by the Progress Rocket Space Centre (RKTs Progress) in Samara, Soyuz-2 is used to place payloads into low Earth orbit in standard configuration but can also support missions to higher orbits using an additional upper stage, most commonly the Fregat, though the smaller Volga is available as a less expensive option. Since its introduction in 2004, Soyuz-2 has gradually replaced earlier Soyuz variants and is launched from the facilities of its R-7 derived predecessors: Site 31/6 at the Baikonur Cosmodrome in Kazakhstan and Sites 43/3 and 43/4 at the Plesetsk Cosmodrome in northwestern Russia, and, since 2016, Site 1S at the Vostochny Cosmodrome in eastern Russia.

The Soyuz2 family includes several variants. The base model, Soyuz2.1a, debuted on 8 November 2004, followed by the Soyuz2.1b, with a 15 percent more powerful third stage, on 27 December 2006. A derivative version, SoyuzST, was introduced in 2011 with modifications for operation at the Guiana Space Centre, the European Space Agency's launch site in French Guiana. Launches from this site were suspended in 2022 following the Russian invasion of Ukraine.

History Development of the Soyuz-2 originated in the early 1990s as the "Rus" program led by RKTs Progress with support from the Government of Russia. Following the dissolution of the Soviet Union, the "Rus" program sought to consolidate Soyuz production within Russia, eliminate reliance on foreign-supplied components, and modernize the aging Soyuz-U and Molniya-M launch vehicles. These earlier rockets relied on a 1960s-era analog flight control system developed by the Ukrainian Polisvit Special Design Bureau.

Development of Soyuz-2 introduced a fully digital flight control system and upgraded engines. Work on the digital flight control system began in 1993 at NPO Avtomatiki in Yekaterinburg, incorporating triple-redundant computers and dual gyroscopes to improve reliability. The modernization program also included upgraded RD-107A and RD-108A engines for the boosters and core stage, featuring redesigned injectors that improved combustion efficiency and increased specific impulse by approximately , as well as the new RD-0124 third-stage engine employing an oxygen-rich staged combustion cycle. Together, these upgrades increased payload capacity by approximately .

Financial constraints during the late 1990s led to a phased implementation of the upgrades. The improved RD-107A and RD-108A engines were completed before the other planned improvements and entered service first on the transitional Soyuz-FG, while the new avionics and structural modifications debuted with Soyuz-2.1a. The RD-0124 engine was later introduced with Soyuz-2.1b.

Soyuz-2.1a made its maiden flight on 8 November 2004 from Plesetsk Cosmodrome on a suborbital test mission and entered operational service in October 2006 with the launch of MetOp-A. The first Soyuz-2.1b launched on 26 July 2008 from Plesetsk with a classified military payload. Between 2010 and 2019, the Soyuz-2 family gradually replaced the Molniya-M, Soyuz-U, and Soyuz-FG launch vehicles.

Variants

Soyuz-2.1a Soyuz-2.1a introduced the family's digital flight control system, replacing the analog system used on earlier Soyuz rockets. The new avionics were physically lighter, enabled in-flight trajectory adjustments, and supported larger payload fairings, permitting the launch of heavier commercial satellites. The variant also used the upgraded RD-107A and RD-108A engines. The third stage retained the RD-0110 engine used on earlier Soyuz family rockets, but adopted enlarged propellant tanks and a revised structure shared with Soyuz-2.1b. Together, these changes increased payload capacity by about .

Soyuz-2.1b Soyuz-2.1b retains the upgrades introduced with the 2.1a and while replacing the third-stage RD-0110 with the more efficient RD-0124, an oxygen-rich staged-combustion engine, the engine increases specific impulse from . Although maximum thrust was slightly reduced from , extended burn time with the same propellant load improved overall performance. The enhanced third stage significantly increased payload capability. From the Baikonur Cosmodrome, payload capacity to low Earth orbit rose from approximately for the 2.1a to for the 2.1b.

Vostochny modifications The Soyuz-2 family received specific modifications for operation from the Vostochny Cosmodrome, aimed at improving reliability, compatibility with ground infrastructure, and safety: The rocket was modified to remain fuelled on the launch pad for up to 100 hours and withstand transport over distances of up to from the manufacturing site in Samara to the Russian Far East. Structural and piping modifications enable vertical payload integration and safely vent excess propellant outside the Mobile Service Tower, minimizing oxygen vapour buildup inside the gantry. Upgraded computer offering six times the performance, reduced weight, and simplified wiring through multiplexing and shared data buses. New nickel-cadmium batteries eliminate the need for a dedicated charging station.

On 1 October 2015, it was revealed that parts of the assembly complex at Vostochny had been incorrectly designed for a different rocket variant, with some structures too small to accommodate Soyuz-2. This issue cast doubt on the planned inaugural launch in December 2015. The first launch successfully took place on 28 April 2016.

Notable missions Suborbital test flight On 8 November 2004, at 18:30 UTC, the first Soyuz2 rocket, in the Soyuz2.1a configuration, was launched from the Plesetsk Cosmodrome in Russia. The rocket followed a suborbital trajectory, with the third stage and Boilerplate landing in the Pacific Ocean.

Maiden launch The first attempt at launching a Soyuz2 to orbit with the MetOp-A satellite occurred on 17 July 2006. It was scrubbed two hours before the launch by an automatic sequence after the onboard computer failed to check the launch azimuth. Fuelling of the rocket was underway at the time, and all launch complex equipment and onboard preliminary checks had proceeded without incident. The rocket was left fuelled on the launch pad for the next attempt on 18 July 2006. Launch was eventually conducted on 19 October 2006.

First crewed mission The first crewed launch of Soyuz2 took place on 9 April 2020, carrying Soyuz MS-16 to the ISS.

Naphthyl fuel Following successful ground testing, a naphthyl fuelled Soyuz2.1b launch took place on 22 October 2022 at Vostochny. Naphthyl is a fuel with fewer aromatic compounds than kerosene, which slightly improves engine performance. There are only minor differences in thermal properties, viscosity, and surface tension, so this did not require significant engine changes.

Launch statistics Since 2006, Soyuz2 rockets have accumulated a total of 170 launches, 165 of which were successful, yielding a success rate.

For Soyuz flights for ESA/Arianespace from French Guiana see Soyuz-ST.

Launch outcomes

Launch sites

List of launches