The RD-107A is a rocket engine developed in the Soviet Union, primarily used in the R-7 Semyorka launch vehicle. It operates on a combination of kerosene and liquid oxygen, providing a thrust of approximately 100 kilonewtons. This engine is notable for its reliability and efficiency, contributing to the success of early space missions. The RD-107A features a unique design with four combustion chambers, allowing for a more compact engine configuration. It played a crucial role in launching the first human, Yuri Gagarin, into space in 1961, marking a significant milestone in the Space Race.