Family: Soyuz-2 (R-7)
Soyuz 2.1a/Fregat-M
Launch statistics
- 82
- Launches (as of July 27, 2026)
- 1
- Successes
- 0
- Failures
- 100.0 %
- Success rate
"Soyuz 2.1a/Fregat-M" does not denote a stand-alone rocket but a specific stack: the baseline Soyuz-2.1a model of the Russian Soyuz-2 family, topped by the optional Fregat-M upper stage. Soyuz-2 is a series of expendable medium-lift launch vehicles built by the Progress Rocket Space Centre (RKTs Progress) in Samara, and is the seventh major iteration of the Soyuz family, itself descended from the R-7. At 46.3 metres tall, 10.3 metres across at its widest and 312 tonnes at lift-off, the vehicle has the same overall dimensions in any of its variants. Soyuz-2.1a was the model that introduced the family's digital flight control system, replacing the analogue electronics of earlier Soyuz rockets. The new avionics were lighter, allowed in-flight trajectory adjustment and supported larger fairings. Its third stage retains the RD-0110 engine of the classic Soyuz, but with enlarged propellant tanks and a revised structure shared with the 2.1b. From Baikonur it places roughly 7,430 kilograms into low Earth orbit. The Fregat-M stage, built by NPO Lavochkin, is what turns the three-stage launcher into a four-stage vehicle able to reach high orbits or interplanetary trajectories. It stands 1.945 metres tall and 3.8 metres in diameter, weighs 7,640 kilograms fuelled, burns hypergolic dinitrogen tetroxide and UDMH through an S5.92 engine, and can restart up to seven times, letting it drop several payloads into different orbits during a single mission.
History
The Rus programme
Soyuz-2 began in the early 1990s under the name "Rus", led by RKTs Progress with backing from the Russian government. After the dissolution of the Soviet Union the aim was threefold: consolidate Soyuz production inside Russia, remove dependence on foreign-supplied components, and modernise the ageing Soyuz-U and Molniya-M, which still flew with an analogue control system designed in the 1960s by the Ukrainian Polisvit bureau.
Digital avionics and engines
Work on the digital flight control system started in 1993 at NPO Avtomatiki in Yekaterinburg, using triple-redundant computers and dual gyroscopes. In parallel the RD-107A and RD-108A engines of the boosters and core stage were upgraded with redesigned injectors that improved combustion and raised specific impulse by about 5 seconds. Together the improvements increased payload capacity by roughly 1,200 kilograms. Financial constraints in the late 1990s forced a phased rollout: the engines arrived first, on the transitional Soyuz-FG, while the avionics and structural changes debuted with the 2.1a.
The 2.1a in service
The first Soyuz-2.1a lifted off on 8 November 2004 at 18:30 UTC from Plesetsk on a suborbital test mission, with the third stage and a boilerplate falling into the Pacific Ocean. Operational service began in October 2006 with the launch of the MetOp-A weather satellite, precisely in combination with a Fregat stage.
What Fregat adds
Fregat, developed by NPO Lavochkin in the 1990s from the spacecraft bus of the Soviet Phobos probes, entered service in February 2000. Its architecture of six spherical tanks arranged in a circle gives it a diameter greater than its height and makes it autonomous, carrying its own guidance, navigation, attitude control and telemetry. With more than 300 payloads deployed and a 97.3% success rate, it is among the most reliable upper stages in operation. The more capable M version appeared on Soyuz-2 flights from 2010 onwards. In 2018, adding a Fregat to a Soyuz-2 launch cost about US$13.5 million.
Current status
Soyuz-2.1a has accumulated 82 launches across all its configurations, the most recent on 14 July 2026. It flies from Site 31/6 at Baikonur, Sites 43/3 and 43/4 at Plesetsk and, since 2016, Site 1S at Vostochny, for which the vehicle received specific modifications.
Launch timeline
| Date | Launch site | Outcome | Payload |
|---|---|---|---|
| Apr 3, 2026, 6:28 AM | 43/3 (43L) | Success | Note: Payload identity uncertain. Meridian is a series of communications satellite for military and civilian use. |
Images