Patent ID: 8707675

Claim:
A hot-gas thruster, comprising: an electric motor operable to selectively supply a drive force; a thruster body having an inlet port, an outlet port, and an inner surface that defines a valve chamber, the inlet port for receiving a flow of hot gas, the outlet port defining a valve seat and a thrust nozzle; a poppet valve disposed at least partially within the valve chamber and including a control surface, a seating surface, an outer surface between the control surface and the seating surface, and a vent orifice in fluid communication with the outlet port, the poppet valve defining a control chamber between the control surface and the inner surface of the thruster body, the control chamber in continuous fluid communication with the inlet port via a fill orifice, the poppet valve movable between a closed position, in which the seating surface engages the valve seat, and a plurality of open positions, in which the seating surface does not engage the valve seat; a suspension spring housing coupled to the poppet valve; a pilot shaft extending through the suspension spring housing and into the poppet valve, the pilot shaft coupled to receive the drive force from the electric motor and responsive thereto to selectively move in either a first direction or a second direction; a pair of preload springs disposed within the suspension spring housing, the preload springs engaging both the suspension spring housing and the pilot shaft and supplying opposing preload forces thereto, wherein: when the pilot shaft moves in the first direction, fluid pressure in the control chamber is vented via the vent orifice to allow the poppet valve to move toward an open position, and when the pilot shaft moves in the second direction, fluid pressure in the control chamber aids the pilot shaft to move the poppet valve toward the closed position.