Patent ID: 8250853

Claim:
A hybrid expander cycle rocket engine comprising: a combustion chamber connected to a nozzle through a throat; a fuel pump driven by a fuel turbine; an oxidizer pump driven by an oxidizer turbine; a heat exchanger formed within the combustion chamber of the nozzle to convert a liquid into a gas; a first fuel line connecting an output of the fuel pump to an inlet of the heat exchanger; a second fuel line connecting an outlet of the heat exchanger to an inlet of the fuel turbine; a third fuel line connecting an outlet of the fuel turbine to an inlet of the combustion chamber; a fuel bypass line with an inlet end connected to the second fuel line and an outlet end connected to the third fuel line and bypassing the fuel turbine; a bypass regulating valve connected in the fuel bypass line to regulate an amount of fuel that bypasses the fuel turbine; a first oxidizer line connecting an outlet of the oxidizer pump to an inlet of the combustion chamber; a second oxidizer line connecting an outlet of the oxidizer pump to a gas generator; a fuel pump to gas generator line to supply some of the fuel to the gas generator; and, a gas generator line connecting an outlet of the gas generator to an inlet of the oxidizer turbine.