Pulsed Electrogasdynamic Thruster for Attitude Control and Orbit Maneuver

A new pulsed electric thruster, named "pulsed electrogasdynamic thruster," for attitude control and orbit maneuver is proposed. In this thruster, propellant gas is introduced into the thrust nozzle through a fast acting gas valve. When the propellant gas partially fills the thruster nozzle in 100~200 microsecond, a short, high voltage pulse is applied to break down and heat the propellant gas. The typical duration of the pulsed discharge is 10 microsecond. The heated propellant gas expands through the nozzle generating a high impulse (~mN-s per pulse) at a high specific thrust (120 micro N-s/joule). The specific impulse (Isp) will be in the range of 1000~1400 sec. This process can be repeated at a frequency which satisfies the spacecraft thrust requirement. The thrust generating mechanism of the proposed thruster is gasdynamic expansion, not magnetohydrodynamic interaction. The proposed thruster is different from the conventional pulsed electrothermal thruster in that the joule heating of the propellant takes place as the propellant gas expands through the divergent nozzle, thereby eliminating the heat and momentum losses at the nozzle throat. Our objectives are: (i) establish proof of concept; (ii) develop an engineering model; and (iii) develop a proto-flight model of the proposed thruster system.