For the Moon race, Korolev's staff started to design the immense N1 rocket in 1961, using the NK-15 liquid fuel rocket engine. He also was working on the design for the Soyuz spacecraft that was intended to carry crews to LEO and to the Moon. As well, Korolev was designing the Luna series of vehicles that would soft-land on the Moon and make robotic missions to Mars and Venus. Unexpectedly, he died in January 1966, before he could see his various plans brought to fruition.