At 19:57 UTC on Wednesday, March 29, Russia’s Soyuz-2.1v rocket launched from Site 43/4 at the Plesetsk Cosmodrome, carrying an unknown payload designated Kosmos-2568 to a Sun-synchronous orbit (SSO).
The identity of the payload is unknown, but it may be another inspector satellite, similar to one flown on a previous Soyuz-2.1v launch. If Kosmos-2568 is an inspector satellite, it may release a subsatellite later on, as previous inspector satellites have done. Kosmos-2542 was believed to have been an inspector satellite, although never confirmed by Russia, and later went on to release Kosmos-2543.
Previous inspector satellite launches have been timed to match the trajectory and flight path of American spy satellites, with the most recent being Kosmos-2561, which was launched mirroring the trajectory of the American spy satellite USA-326, launched on the NROL-87 mission in February 2022.
Plesetsk Cosmodrome is one of three Cosmodromes currently used by the Russian Military as well as Roscosmos, Russia’s state-owned space agency. The other two Cosmodromes currently in use are Baikonur Cosmodrome, located in the former Soviet Union incorporated nation of Kazakhstan, and Vostochny Cosmodrome, located in Russia’s Far East.
Plesetsk itself is located in the Arkhangelsk Oblast, north of Moscow and on the Barents Sea. Plesetsk was the second Cosmodrome built by the then Soviet Union and was initially intended to test the R-7 intercontinental ballistic missile. Plesetsk’s location would have allowed operational R-7s to target locations in the United States and North America.
During the 1960s, the former R-7 pads were repurposed to allow launches of vehicles derived from the R-7 ICBM, such as the Vostok rocket and the Soyuz family of launch vehicles. The first orbital launch from Plesetsk occurred on March 17, 1966, when a Vostok-2 rocket launched Kosmos-112, a first-generation Soviet optical reconnaissance satellite to low Earth orbit (LEO).
By 1997, 33 years after its first launch, the cosmodrome had seen over 1,500 launches, making it the most active cosmodrome in Russia at the time. Since then, the Cosmodrome has gone on to launch the R-7-derived Soyuz, the Cosmos-3M, Rokot, Tsyklon, and the most recent addition to the launchers, Angara.
Plesetsk is currently the host of the only operational Angara launch site, but another pad is currently under construction at Vostochny Cosmodrome, with launches expected to begin in 2023.
The Soyuz-2.1v doesn’t look like a traditional Soyuz-2 launch vehicle and was even referred to as Soyuz 1 during development, which began in the mid-to-late 2000s.
Since the Soyuz-2.1v rocket doesn’t use the four side boosters as other Soyuz-2 rockets do, the first stage replaces the RD-108A engine typically found on the Blok-A first stage with an NK-33 engine, which was initially developed for the N-1 Moon rocket. Since the NK-33 engine doesn’t feature any gimbaling capabilities, a four-nozzled RD-0110R engine provides thrust vectoring control on the first stage.
Since the Soyuz-2.1v lacks the four side boosters, it is also the only Soyuz rocket that does not feature a “Korolev Cross,” which occurs when the four boosters separate from the first stage. The planned Soyuz-5 rocket, which will replace all of the Soyuz-2 rockets, will also not feature the Korolev Cross.
The NK-33 engine on the first stage was initially developed for the N-1 Moon rocket, which would have featured 30 NK-33s on the first stage. The engine runs on a staged combustion cycle and uses RP-1, a refined form of kerosene, and liquid oxygen. The NK-33 engine never got a chance to fly on the N-1, but found a new purpose as the AJ-26 engine, used on the then Orbital Sciences Antares 110 rocket, with the engine being refitted by Aerojet Rocketdyne.
After an engine failure on the fifth flight of Antares, the NK-33/AJ-26 was replaced by the RD-181 engine, itself derived from the RD-180 engine used on the United Launch Alliance Atlas V.
After the current stockpile of NK-33s runs out, the Soyuz-2.1v will use the RD-193 engine, a derivative of the RD-191 engine currently used by Angara.
The second stage uses the same RD-0124 as the second stage of the Soyuz-2.1b. Instead of using the optional Fregat upper stage of the other Soyuz-2 rockets, the Soyuz-2.1v uses the Volga upper stage.
(Lead photo: A Soyuz-2.1v launches from Plesetsk with Kosmos 2542 and 2543 on board in November 2019. Credit: Russian Ministry of Defense)