A rocket needs to produce enough thrust to overcome gravity and lift its own weight. Rockets burn liquid hydrogen and oxygen in a specially built combustion chamber. For every pound of rocket fuel burned, a pound of exhaust gas is allowed to escape from a nozzle at the base of the rocket. As the high-temperature, high-velocity gases are fired downwards, they exert an equal, opposite force that fires the rocket upwards.
Like most engines, rockets burn fuel. Most rocket engines turn the fuel into hot gas. The engine pushes the gas out its back. The gas makes the rocket move forward. A rocket is different from a jet engine. A jet engine needs air to work. A rocket engine doesn’t need air. It carries with it everything it needs. A rocket engine works in space, where there is no air.
There are two main types of rocket engines. Some rockets use liquid fuel. The main engines on the space shuttle orbiter use liquid fuel. The Russian Soyuz uses liquid fuels. Other rockets use solid fuels. On the side of the space shuttle are two white solid rocket boosters. They use solid fuels. Fireworks and model rockets also fly using solid fuels.
In space, an engine has nothing to push against. So how do rockets move there? Rockets work by a scientific rule called Newton’s third law of motion. English scientist Sir Isaac Newton listed three Laws of Motion. He did this more than 300 years ago. His third law says that for every action, there is an equal and opposite reaction. The rocket pushes on its exhaust. The exhaust pushes the rocket, too. The rocket pushes the exhaust backward. The exhaust makes the rocket move forward.
This rule can be seen on Earth. Imagine a person standing on a skateboard. Imagine that person throwing a bowling ball. The ball will go forward. The person on the skateboard will move, too. The person will move backward. Because the person is heavier, the bowling ball will move farther.
Picture Credit : Google
