Rocket engine with redundant capabilities

For a space craft vehicle a redundant system including a rocket engine for providing propulsion force, said rocket engine having an injector for feeding oxygen and hydrogen into a thrust producer means consisting of a single thrust chamber, a source of liquid hydrogen and a source of liquid oxygen connected to said injector and being located relative to said thrust chamber so that the center of gravity of said sources is in a predetermined location for each volumetric condition of said sources and bears a given and fixed relationship to the thrust chamber, said rocket engine comprising at least a pair of generally identical independent systems wherein each of said systems includes fluid connection means for conducting oxygen from said source to said oxygen injector and for conducting hydrogen from said source through indirect heat exchange relationship with said thrust chamber and then to said hydrogen injector, turbopump means for flowing the oxygen and hydrogen through said fluid connecting means, said sources being disposed relative to said thrust chamber so that the center of gravity remains substantially in coincidence with the centerline of said thrust chamber as the oxygen and hydrogen is used up.