Soyuz2 (, GRAU index: 14A14) is a Russian expendable medium-lift launch vehicle 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 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.
The Soyuz-2 project was initiated in the early 1990s by RKTs Progress with support from the Government of Russia as the "Rus" program. Following the Dissolution of the Soviet Union, it aimed to consolidate production within Russia and replace foreign-supplied systems while modernizing the aging Soyuz-U and Molniya-M launch vehicles. These earlier rockets relied on 1960s-era analog guidance systems developed by the Ukrainian Polisvit Special Design Bureau.
Soyuz-2 introduced a fully digital flight control system and upgraded engines. Development of the digital system began in 1993 at NPO Avtomatiki in Yekaterinburg, incorporating triple redundancy and dual gyroscopes to improve reliability. The modernization program also included updated RD-107A and RD-108A engines for the boosters and core stage, as well as the development of the new RD-0124 third-stage engine employing oxygen-rich staged combustion. Together, these upgrades were intended to increase payload capacity by approximately .
Financial constraints in the late 1990s led to a phased implementation. The upgraded RD-107A and RD-108A engines first flew on the transitional Soyuz-FG, while the majority of structural and avionics changes were incorporated into Soyuz-2.1a. The new RD-0124 engine was later introduced with Soyuz-2.1b.
Soyuz-2.1a conducted its maiden suborbital flight from Plesetsk Cosmodrome on 8 November 2004 and entered operational service in October 2006 with the launch of MetOp-A for the European Space Agency and EUMETSAT. Soyuz-2.1b followed in December 2006. Between 2010 and 2019, the Soyuz-2 family gradually replaced Molniya-M, Soyuz-U, and Soyuz-FG.
Soyuz2.1a introduced the digital flight control system, replacing the analog unit used on previous Soyuz rockets. The system enabled in-flight trajectory adjustments and supported larger payload fairings, permitting the launch of heavier commercial satellites.
The vehicle uses upgraded RD-107A and RD-108A engines, featuring over 1,000 single-component injectors replacing earlier dual-component designs, improving combustion efficiency and increasing specific impulse by approximately .
The third stage retained the RD-0110 engine but adopted enlarged propellant tanks and a revised structure shared with Soyuz-2.1b. Combined with the lighter avionics, these changes increased payload capacity by about .
The first Soyuz2.1a launch took place on 8 November 2004 from Plesetsk Cosmodrome Site 43 with a boilerplate payload simulating a Zenit-8 reconnaissance satellite.
Soyuz2.1b retains the upgrades of the 2.1a and introduces a new third stage powered by the RD-0124 engine. Using oxygen-rich staged combustion, 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.
The first Soyuz2.1b launch occurred on 26 July 2008 from Plesetsk Cosmodrome Site 43 with a classified military payload.
The Soyuz-2 family received specific modifications for operation from the Vostochny Cosmodrome, aimed at improving reliability, compatibility with ground infrastructure, and safety:
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.
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.
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.
The first crewed launch of Soyuz2 took place on 9 April 2020, carrying Soyuz MS-16 to the ISS.
Following successful ground testing, a naphthyl (Russian: ýðÃÂÃÂøû) fueled Soyuz2.1b launch took place on 22 October 2022 at Vostochny. Naphthyl is an environmentally safe hydrocarbon fuel with fewer aromatic compounds than kerosene, which also slightly improves engine performance. There are only minor differences in thermal properties, viscosity, and surface tension, so this did not require significant engine changes.
Since 2006, Soyuz2 rockets have accumulated a total of 162 launches, 157 of which were successful, yielding a success rate.
For Soyuz flights for ESA/Ariannespace from French Guiana see Soyuz-ST.