Closed cycle power system

A closed cycle power system adaptable for use in terrestrial and extraterrestrial applications. A combustor is provided for combusting a fuel and an oxidizer at stoichiometric conditions. The resulting combustion efflux is combined with a third product to form a working fluid. The third product has the same atomic and molecular constituents as the fuel and oxidizer. An engine is provided for receiving the working fluid and driving power output therefrom. The exhaust from the engine is cooled and a controlled portion therefrom is extracted and condensed. The controlled portion is separated into its original atomic constituents for storage under high pressure and ultimate reuse as said fuel and oxidizer. The remaining portion of the exhaust is recompressed and reheated. That remaining portion becomes said third product which becomes combined with the comsution efflux to form a working fluid. The resulting stoichiometric closed loop process provides an efficient source of power.