Booster-sustainer rocket engine and method

A liquid rocket propulsion system comprising:

• an oxidant storage tank for storing a liquid oxidant propellant;
• a fuel storage tank for storing a liquid fuel propellant;
• a multiplicity of turbopumps for pressurizing and gasifying the liquid propellants, each said turbopump including,
• a pump impeller for pressurizing one of the propellants introduced into the turbopump,
• a preburner wherein gasification occurs to produce a fluid flowstream, and
• a turbine wheel for extracting energy from the flowstream to drive the pump impeller;
• combustion means for combusting the multiplicity of fluid flowstreams produced by said turbopumps to produce exhaust gases;
• and
• nozzle means for expelling the exhaust gases from the propulsion system to produce thrust;
• wherein said multiplicity of turbopumps gasify substantially all of the propellants before the propellants are delivered to the combustion means, and the plurality of turbopumps include at least two oxidant turbopumps, each said oxidant turbopump combining a small portion of the fuel with a substantial portion of the oxidant and combusting the mixture within the oxidant turbopump's preburner to produce a gasified oxidizer-rich fluid flowstream, and at least one fuel turbopump that combines a small portion of the oxidizer with a substantial portion of the fuel within the fuel turbopump's preburner to produce a gasified fuel-rich fluid flowstream.

A method of supplying propellant to a liquid rocket having a liquid fuel stored within a fuel storage tank, a liquid oxidizer stored within an oxidizer storage tank, and a nozzle having a throat area and an exit outlet, the method comprising the steps of:

• preburning a portion of the fuel with a portion of the oxidant to gasifying substantially all of the propellants to form a plurality of fluid flowstreams;
• pressurizing the liquid propellants apart from the storage tanks using substantially all of the gasified propellants as the energy source for pressurizing the liquid propellants;
• mixing the fluid flowstreams and combusting the mixture to produce exhaust gases;
• expelling the exhaust gases through the nozzle to produce thrust.

A method of operating a rocket propulsion system having a liquid fuel stored within a fuel storage tank, a liquid oxidant stored within an oxidizer storage tank, a plurality of oxidant turbopumps for pressurizing the oxidant, each oxidant turbopump producing an oxidant rich flowstream, a plurality of fuel turbopumps for pressurizing the fuel, each fuel turbopump producing a fuel rich flowstream, combustion means for receiving, mixing and combusting the plurality of oxidant rich flowstreams and the plurality of fuel rich fluid flowstreams to produce exhaust gases, and a nozzle for expelling the exhaust gases from the propulsion system to produce thrust, the nozzle having a throat and an exit opening, the method comprising the steps of:

• operating all of said fuel and oxidant turbopumps at preselected flowrates during a booster phase of a flight, the preselected flowrates being selected such that the combined fuel rich flowstreams and oxidant rich flowstreams create an oxidant rich mixture within the combustion means during the booster phase of flight;
• selectively shutting down a primary group of the oxidant turbopumps during a sustainer phase of the flight, while operating the remaining oxidant turbopumps and the fuel turbopumps substantially at the same preselected flowrates as used during the booster phase of the flight, the preselected flowrates of the remaining operational turbopumps being selected such that the combustion means is supplied with a fuel rich mixture during the sustainer phase of the flight.