US Patent 7900435 Micro-coaxial injector for rocket engine

An improved coaxial injector for injecting first and second propellants into a combustion chamber of a rocket engine is provided. The injector includes a first plate, a second plate, a plurality of channels formed in the first plate, and a plurality of tubes extending through the second plate and into the plurality of channels. The tubes inject a first propellant, such as an oxidizer, into the combustion chamber, and the channels inject a second propellant, such as a fuel, around the tubes and into the combustion chamber.