by NASA

“ The Integrated Powerhead Demonstrator is a corner-stone of the Integrated High Payoff Rocket Propulsion Technologies program, which seeks to double the performance and capability of today’s state-of-the-art rocket propulsion systems while decreasing costs associated with military and commercial access to space. The intended full-flow engine cycle is a key component in achieving this goal. ”

“ The oxidizer preburner is the first flight-capable, oxygen-rich preburner developed in the United States for a large-scale engine. The Space Shuttle main engine makes use of a preburner that generates hydrogen-rich steam -- the only American rocket engine to do so. But whereas the Shuttle main engine burns only a small amount of oxygen prior to entry into the main combustion chamber, all the oxygen used in the demonstrator engine system will be sent through the preburner. ”

“ The use of oxygen-rich steam to power the demonstrator’s oxygen turbopump is intended to dramatically increase safety of engine system operation, limiting seal failure between the pump and the turbine that could leak extremely hot gases into the turbine and cause them to burn prematurely.
Aerojet also is responsible for development of the demonstrator engine’s fuel preburner, designed to supply the fuel turbopump’s turbine with hot, hydrogen-rich steam. The Aerojet team also has designed, fabricated and tested the channel wall nozzle, a component that directs the rocket engine’s exhaust. ”