How does a rocket motor work? A rocket motor operates on the principle of action and reaction. Its upward thrust is the reaction to a downward force created by escaping gases. These gases are produced when two propellents burn inside the rocket. The two propellents, the fuel and the oxidant, are pumped by turbines into the combustion chamber. Here, the fuel is ignited. When the fuel burns, it releases energy in the form of hot gases. The gases escape through the exhaust at great speed, providing the thrust which forces the rocket upwards.
The two rocket propellents are stored in tanks. These tanks are the largest part of the rocket's structure, and the weight of the propellents represents about 90% of the total weight of the rocket motor. The turbines are located below the tanks. Their function is to pump the propellents from the tanks along pipes. The propellents pass through control valves and injectors into the combustion chamber.