A reusable, high-performance, liquid-propellant rocket engine is being developed for the Space Shuttle Orbiter vehicle. The engine is a high-pressure design based on the staged combustion cycle. Control is accomplished with an electronic digital system. This controller accepts vehicle commands for start, shutdown, mixture ratio, and thrust level, plus providing appropriate signals to five major propellant valves: main fuel, main oxidizer, chamber coolant, and two preburner oxidizer valves.
Many unique design features, such as regenerative cooling at high chamber pressure, a high-efficiency three-stage fuel pump, a dual-inlet oxidizer pump, and an electric control system, are incorporated to satisfy the life, performance, and reliability requirements of the Space Shuttle Orbiter Main Engine.