Abstract: A method of cooling a rocket engine that includes removal of a gaseous propellant from a tank containing liquid propellant, thereby cooling the propellant in the tank, cooling a rocket engine with a coolant, thereby heating the coolant, and transferring heat from the heated coolant into the propellant in the tank, thereby heating the propellant in the tank and maintaining the pressure in the tank. In certain embodiments, the coolant is injected into the rocket engine after transferring heat from the rocket engine to the propellant in the tank.

Abstract: A check valve is disclosed that includes a base having a porous first surface, a keeper coupled to the base, and a flexible leaf with a first section that is fixedly coupled between the keeper and the base and a second section that is cantilevered from the first section. The leaf has a first position when the leaf is fully in contact with the base and a second position when the leaf is fully in contact with the keeper. The leaf is configured to sealingly cover the porous first surface when the leaf is in the first position. The leaf is in an unstressed configuration when in the first position, and a maximum stress in the leaf is less than the yield stress when the leaf is in the second position. The check valve is particularly suited for use with cryogenic fluids such as liquid hydrogen and liquid oxygen.

Abstract: An improved coaxial injector for injecting first and second propellants into a combustion chamber of a rocket engine is provided. The injector includes a first plate, a second plate, a plurality of channels formed in the first plate, and a plurality of tubes extending through the second plate and into the plurality of channels. The tubes inject a first propellant, such as an oxidizer, into the combustion chamber, and the channels inject a second propellant, such as a fuel, around the tubes and into the combustion chamber.

Abstract: A coolant system for a rocket propulsion system having a rocket engine and a propellant tank includes a first heat exchanger that is operatively coupled to the rocket engine. The cooling system also includes a second heat exchanger that is operatively coupled to the propellant tank, a coolant tank that is configured to hold a coolant, and a pump. The cooling system also includes a flow circuit, through which the coolant flows with the aid of the pump. The flow circuit is defined by the pump, the first heat exchanger, the second heat exchanger and the coolant tank. The coolant is pumped by the pump from the coolant tank to the first heat exchanger. The heat of combustion from the rocket engine is transferred to the coolant to cool the rocket engine. The heated coolant transfers the heat therein to the propellant with the second heat exchanger, thereby causing a pressure of the propellant in the propellant tank to be maintained at a desired level.

Abstract: The present invention relates to rocket engine combustion chambers, and more particularly to an improved rocket engine combustion chamber having a jacket. In some embodiments, a combustion system for a rocket engine includes an injector, a cylindrical combustion chamber, and a jacket coupled to the combustion chamber and to the injector. The combustion chamber can expand axially and/or radially with respect to the jacket. The outer surface of the combustion chamber includes a plurality of flow channels. One or more piston seals and/or bellows can be included to allow axial expansion of the combustion chamber with respect to the jacket. A gap formed between the inner surface of the jacket and the outer surface of the combustion chamber allows for radial expansion of the combustion chamber with respect to the jacket.

Abstract: A system and method of driving a fuel pump and/or an oxidizer pump in a propulsion system includes pumping an oxidizer from an oxidizer supply to a rocket engine with the oxidizer pump. A first portion of the pumped oxidizer is used for combustion in the rocket engine. The heat from the combustion of the first portion of the oxidizer is then transferred to a second portion of the pumped oxidizer to convert the second portion of the oxidizer to a super-heated gaseous oxidizer. The super-heated gaseous oxidizer operates a motor, which drives the oxidizer pump and/or the fuel pump.

Abstract: A propulsion system for a rocket engine and a method of cooling a rocket engine includes a propellant tank fluidically coupled to the rocket engine to hold a pressurized propellant, a coolant tank to hold a coolant, a first heat exchanger thermally coupled to the rocket engine and fluidically coupled to the coolant tank, a second heat exchanger thermally coupled to the propellant tank and fluidically coupled to the first heat exchanger, and a third heat exchanger disposed inside the propellant tank to thermally couple a propellant withdrawn from the tank for combustion to a propellant disposed inside the tank. The coolant flows from the coolant tank to the first heat exchanger and through the first heat exchanger to cool the rocket engine. The propellant withdrawn from the propellant tank receives heat from the propellant disposed inside the tank through the third heat exchanger to convert to a gaseous propellant when withdrawn from the propellant tank as a liquid propellant.