What is a rocket?
A rocket is a vehicle or engine that moves by pushing hot gas out of a nozzle at high speed. It carries its own fuel and oxygen, so it can work in space where there is no air.
Rocket engines burn fuel with an oxidizer, a substance that supplies oxygen. The burning produces hot, high-pressure gas that rushes out of the nozzle at the back. As the gas is forced backward, the rocket is pushed forward. Rockets can use liquid fuels, like liquid hydrogen and oxygen, or solid fuels packed into the casing.
Rockets were invented in China around the 1200s, using gunpowder for fireworks and weapons. Modern rocketry was pioneered by Konstantin Tsiolkovsky in Russia, Robert Goddard in the United States, who launched the first liquid-fueled rocket in 1926, and Hermann Oberth in Germany.
Launching to space
Large space rockets usually have several stages, which drop away when their fuel runs out, making the rest of the rocket lighter. Companies like SpaceX now land and reuse rocket boosters, greatly reducing the cost of reaching orbit.
Did You Know?
NASA's Saturn V, which carried astronauts to the Moon, was about 110 meters tall and remains one of the most powerful rockets ever flown.