Liquid oxygen is the cryogenic liquid form of oxygen.

The Moon is Earth's only natural satellite and is the fifth-largest satellite in the Solar System.

A multistage rocket or step rocket is a launch vehicle that uses two or more rocket stages, each of which contains its own engines and propellant.

NASA (National Aeronautics and Space Administration) is an independent agency of the United States federal government responsible for the country's civilian space program and for aeronautics and aerospace research.

Robert H.

Sergei Korolev was a prominent Soviet engineer and spacecraft designer during the Space Age.

Spaceflight (or space flight) is an application of astronautics to fly objects, usually spacecraft, into or through outer space, either with or without humans on board.

A space station is a large spacecraft that remains in low Earth orbit for extended periods of time.