The NK-33 is a liquid rocket engine developed in the 1960s by the Kuznetsov Design Bureau in the Soviet Union. It was designed for use in the N-1 rocket, which aimed to send humans to the Moon. The engine is known for its high performance and efficiency, utilizing a combination of kerosene and liquid oxygen as propellants. After the cancellation of the N-1 program, many NK-33 engines were stored and later repurposed for other space missions. The engine gained renewed interest in the 1990s and has been used in various launch vehicles, including the Antares rocket, showcasing its reliability and advanced technology.