PROPULSION ENGINE TYPES Chemical propellant rocket engines produce high-speed exhaust gases from high temperature chemical combustion. Combustion occurs when two elements react when combined and generate heat. In a chemical engine, the fuel reacts rapidly with the oxidizer. Fuel and oxidizers are both called propellants. There are two basic types of such chemical engines, those using liquid propellants (example: fuels such as gasoline and kerosene combined with oxidizers such as oxygen and nitrogen tetroxide) and those that use solid propellants (example: gunpowder). In solid propellants, the fuel and oxidizer are mixed together but do not burn until they are ignited. In liquid propellant engines, the fuel and oxidizer mix in the combustion chamber, where they ignite. 18 of 39
Florida Space Research Institute ©2002