Patent ID: 7900436

Claim:
A gas-generator augmented expander cycle rocket engine, comprising: a first turbopump for pumping fuel, said first turbopump comprising a shaft having a pump at a first axial end and a turbine at a second axial end; a second turbopump for pumping oxidizer, said first turbopump comprising a shaft having a pump at a first axial end and a turbine at a second axial end; a gas-generator adapted for receiving a first portion of fuel output from said first turbopump and a first portion of oxidizer output from said second turbopump and ignite to discharge a heated combustion gas; a heat exchanger arranged downstream of said gas-generator, said heat exchanger being close-coupled to said gas-generator and having a first conduit for receiving a heated output of combustion gas from said gas-generator, and a second conduit for transferring heat arranged adjacent to said first conduit; a thrust chamber assembly comprising a primary combustion chamber at a forward facing end and a nozzle at a rearward facing end, said thrust chamber assembly having walls with a plurality of cooling passages therein for receiving a second portion of fuel output from said first turbopump and transferring heat to the second portion of the fuel passing through the cooling passages to cool said thrust chamber assembly, wherein said cooling passages and an input of the second conduit of the heat exchanger are in communication for discharging the second portion of fuel from the cooling passages into the input of the second conduit of said heat exchanger to further heat the second portion of fuel; wherein said second conduit is in communication with at least one flow path in fluid communication with a turbine of one or both of said first turbopump and said second turbopump for discharging said second portion of fuel from said second conduit into the at least one flow path in fluid communication with the turbine of one or both of said first turbopump and said second turbopump, and for driving the turbine of one or both of said first turbopump and said second turbopump by the second portion of the fuel heated by passage through the second conduit of said heat exchanger and not exposing said first turbopump and said second turbopump to combusted gas from either the gas-generator or the primary combustion chamber; and a fuel output conduit for passing a third portion of said fuel output from said first turbopump, and an oxidizer output conduit for passing a second portion of oxidizer output from said second turbopump into the primary combustion chamber of said thrust chamber assembly, for forming combustion products for discharge from the nozzle of said thrust chamber assembly to provide thrust to propel the rocket.