Abstract: Catalyst beds for monopropellant propulsion systems are heated by resistance heating through a conductive material that is incorporated in the catalyst bed and a pair of electrodes on opposite sides of the bed. Imposition of a voltage across the electrodes to heat the bed is performed at will without consumption of any heating components, and heating of the bed is achieved rapidly and uniformly across the entire bed.

Abstract: A propulsion system with a divergent-convergent nozzle is provided with variable thrust by a pintle whose position relative to the nozzle throat is controlled by an actuator that includes a rotor that external to, and encircling, the nozzle, and that is coupled to either the pintle or to the nozzle shell by a linkage that translates the rotary movement of the rotor into linear movement of either the pintle or the shell.

Abstract: An air inlet duct for an air-breathing combined-cycle aircraft engines is internally divided into separate channels for low-speed and high-speed components of the engine, and contains one or more movable panels that are fully contained within the duct and pivotal between an open position in which incoming air is directed to both channels and a closed position in which all incoming air is directed to the channel leading to the high-speed engine. This integrated duct utilizes all incoming air at all stages of flight with no change in either the geometry of the air capture portion of the engine or the engine itself, and no exposure of movable leading edges. The result is a minimum of shock waves and a high degree of efficiency in operation of the engine.

Abstract: Heat is extracted from the combustion gas in a rocket engine combustion chamber by diverting portions of the gas through channels in the nozzle wall. The channels are layered between channels of coolant, which in expander cycle rocket engines is uncombusted fuel, to achieve intimate heat exchange between the combustion gas and the fuel. The combustion gas channels are relatively short, returning combustion gas thus cooled to the chamber interior. By drawing combustion gas from the chamber interior into the chamber wall, the cooling process no longer relies on the combustion gas boundary layer for heat transfer as in the prior art.