Rocket Engine

A rocket engine is a reaction engine that produces thrust, in accordance with Newton's third law, by ejecting reaction mass rearward, typically through a combustion chamber, injectors and a nozzle that accelerates hot gases to generate forward motion. Unlike a jet engine, a rocket engine carries its own oxidizer, letting it operate outside the atmosphere, which is the property that makes spaceflight possible. Modern liquid-propellant rocket engine development accelerated through the 20th century in the United States and the Soviet Union; the first American liquid-propellant rocket engine company, Reaction Motors Inc., was founded in 1941, and rocket engines went on to power the Saturn V program from 1961 to 1975 and the Space Shuttle from 1981 to 2011.