Rocket engines are powerful devices that propel rockets into space by producing thrust. They work on the principle of Newton's third law of motion: for every action, there is an equal and opposite reaction. When rocket fuel burns, it creates hot gases that are expelled out of the engine at high speed, pushing the rocket forward. This technology is essential for space exploration and satellite deployment. There are two main types of rocket engines: liquid rocket engines and solid rocket engines. Liquid engines use liquid fuel and oxidizer, allowing for more control during flight, while solid engines use a pre-packed mixture that ignites all at once. Both types have been crucial in missions led by organizations like NASA and SpaceX.