The RD-107 and its sibling, the RD-108, are a type of rocket engine initially used to launch R-7 Semyorka missiles. RD-107 engines were later used on space launch vehicles based on the R-7. As of 2021, very similar RD-107A and RD-108A engines are used to launch the Soyuz-2.1a, and Soyuz-2.1b, which are in active service.
Rocket engine RD-107 "Vostok" in the Museum of Space and Missile Technology (Saint Petersburg).
The R-7 Semyorka, officially the GRAU index 8K71, was a Soviet missile developed during the Cold War, and the world's first intercontinental ballistic missile. The R-7 made 28 launches between 1957 and 1961. A derivative, the R-7A, was operational from 1960 to 1968. To the West it was unknown until its launch. In modified form, it launched Sputnik 1, the first artificial satellite, into orbit, and became the basis for the R-7 family which includes Sputnik, Luna, Molniya, Vostok, and Voskhod space launchers, as well as later Soyuz variants. Various modifications are still in use and it has become the world’s most reliable space launcher.
R-7 Semyorka photographed at Baikonur on a Russian stamp from 2004