KVD-1 was an upper stage LOX/LH2 cryogenic engine developed by Isayev Design Bureau (now KB KhIMMASH) of Russia in early 1960s. It is a modified version of RD-56 which was developed with an intention to manufacture cryogenic engine for upper stage of Lunar N-1 launch vehicle. It was to be used in USSR moon missions. KVD-1 can produce engine thrust of 7.5 tonnes.