Combustion

Combustion

Propulsion encompasses all aerospace systems generating thrust. Depending on the flight environment and the performance objectives, the range of technologies employed is vast. Orbital flight often relies on electric propulsion, where thrusters leverage the momentum of ionized gases accelerated in electromagnetic fields to control spacecrafts’ trajectories. Rocket engines and gas turbines, on the other hand, rely on the reactions between fuel and oxidizer molecules (combustion), and the heat it produces to expand the exhaust gases and ultimately generate thrust. Regardless of whether the aircraft cruises at subsonic, supersonic or hypersonic speeds, the air surrounding it supplies the oxidizer. The tremendous thrust levels required to lift rockets off the ground however, together with the absence of an atmosphere in space, means that rockets have to carry both fuel of oxidizer, which determines in particular the state and composition of the fuel source.