Abstract: In a spacecraft for operating a thruster that includes a microwave source, a resonant cavity, and a source of propellant which the thruster converts to hot gas and directs via a nozzle to generate thrust, a method includes operating the thruster in an ignition mode in which the microwave source outputs power at a first rate, and operating the thruster in a propulsion mode in which the microwave source outputs power at a second rate higher than the first rate.

Abstract: The disclosed propulsion system of a space vehicle and the methods of operating the propulsion system use a microwave energy source to heat propellant in a propellant chamber that pierces and traverses a waveguide carrying the microwave energy. In some implementations, the microwave energy ionizes and further heats the propellant in the propellant chamber. The partially ionized and heated propellant may exit the propellant chamber via a nozzle to generate thrust.

Abstract: A multi-mode thruster system for use in a spacecraft includes a microwave source; a cavity coupled to the microwave source and including a first inlet to receive a first fluid and a second inlet to receive a second fluid; and a nozzle provided at one end of the cavity. The thruster operates in a microwave electrothermal thruster (MET) mode to (i) generate a standing wave in the cavity using the microwave source and (ii) raise a temperature of the first fluid to generate a first hot gas that exits the cavity via the nozzle to generate thrust. The thruster operates in a chemical propulsion mode to (i) produce a reduction-oxidation reaction between the first fluid and the second fluid and (ii) generate a second hot gas that exits the cavity via the nozzle to generate thrust.

Abstract: The disclosed propulsion system of a space vehicle and the methods of operating the propulsion system use a microwave energy source to heat propellant in a propellant chamber that pierces and traverses a waveguide carrying the microwave energy. In some implementations, the microwave energy ionizes and further heats the propellant in the propellant chamber. The partially ionized and heated propellant may exit the propellant chamber via a nozzle to generate thrust.

Abstract: A multi-mode thruster system for use in a spacecraft includes a microwave source; a cavity coupled to the microwave source and including a first inlet to receive a first fluid and a second inlet to receive a second fluid; and a nozzle provided at one end of the cavity. The thruster operates in a microwave electrothermal thruster (MET) mode to (i) generate a standing wave in the cavity using the microwave source and (ii) raise a temperature of the first fluid to generate a first hot gas that exits the cavity via the nozzle to generate thrust. The thruster operates in a chemical propulsion mode to (i) produce a reduction-oxidation reaction between the first fluid and the second fluid and (ii) generate a second hot gas that exits the cavity via the nozzle to generate thrust.

Abstract: A thruster system for use in a spacecraft includes a microwave source, a resonant cavity coupled to the microwave source, wherein the microwave source is configured to generate a standing wave field in the resonant cavity, a nozzle provided at one end of the resonant cavity; and at least one injector configured to inject propellant into the resonant cavity so as to create a rotating circumferential flow. The standing wave field raises a temperature of the injected propellant to provide thrust by way of a hot gas exiting the resonant cavity via the nozzle.

Abstract: A thruster system for use in a spacecraft includes a microwave source, a resonant cavity coupled to the microwave source, wherein the microwave source is configured to generate a standing wave field in the resonant cavity, a nozzle provided at one end of the resonant cavity; and at least one injector configured to inject propellant into the resonant cavity so as to create a rotating circumferential flow. The standing wave field raises a temperature of the injected propellant to provide thrust by way of a hot gas exiting the resonant cavity via the nozzle.