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: 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 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.