A hybrid propulsion system is a system in which the propellant is stored in two different states of matter. In the case of this project, we will be dealing with a classical hybrid which uses a solid fuel grain and a liquid oxidizer. A hybrid motor has three major components: the oxidizer tank, the oxidizer valve regulation system, and the combustion chamber assembly. The oxidizer tank holds a pressurized liquid oxidizer and the valve varies the oxidizer flow into the combustion chamber. As oxidizer is pushed into
the chamber, it is atomized by the injector to facilitate its combustion with the solid fuel, which in turn generates hot exhaust gases. These gases are then accelerated through the nozzle to generate thrust.
There are many benefits to using a hybrid motor over typical liquid or solid fuel motors. For instance, a hybrid motor includes elements of a liquid motor with far less complexity. It can have a higher specific impulse and safer fabrication and storage compared to a liquid or solid fuel motor. It can also achieve variable thrust and be less expensive than a liquid motor. There are also disadvantages to a hybrid motor. In general, hybrid motors have -lower combustion efficiency than liquid fuel motors. They also have a lower system density impulse and some fuel remains after the motor burns, reducing the overall efficiency.