Abstract: A Hall thruster for use with a condensable propellant including a plasma accelerator including an anode for providing plasma discharge, a distributor for distributing the condensable propellant in a liquid or vaporized state, and an electric circuit including a cathode for emitting electrons attracted to the anode and for neutralizing ion flux emitted from the plasma accelerator. A condensable propellant feed system includes a storage vessel for storing the condensable propellant and providing liquid condensable propellant at a controlled pressure. A condensable propellant flow controller includes a pressure reducing device for controlling the flow rate of the liquid condensable propellant. A vaporizer at or above the vaporization temperature of the liquid condensable propellant vaporizes the liquid condensable propellant at a predetermined vaporization rate and flow rate.

Abstract: A solar powered spacecraft power system including a solar photovoltaic array, an electric propulsion system connected directly to the solar photovoltaic array in parallel with the spacecraft power system; the electric propulsion system including a Hall effect thruster, a thruster power supply for driving the thruster; a sensor for sensing the power output of the solar array and a controller responsive to the power output of the solar array and configured to periodically adjust an operating parameter of the thruster to operate the thruster at the maximum available output power of the solar array including comparing a previous solar array output power level with a later solar array output power level, and incrementing the operating parameter with a positive value if the later is greater and with a negative value if the later is lesser; a solar powered spacecraft power system including a solar photovoltaic array, an electric propulsion system connected directly to the solar photovoltaic array, and a power manage

Abstract: An electrospray source useful for a variety of applications and including an emitter with a porous media flow distributor having a surface forming multiple Taylor cones. A casing about the porous media flow distributor controls the direction of a working fluid through the porous media. An extractor is at a potential different than the emitter for forming the Taylor cones. A guard electrode is disposed between the emitter and the extractor and is at or above the potential of the emitter for shaping the electric field formed between the emitter and the extractor.

Abstract: An iodine fueled plasma generator system includes a plasma generator. At least one storage vessel is configured to store condensed phase iodine therein. A heating device proximate to the storage vessel is configured to create iodine vapor from the condensed phase iodine. A propellant management subsystem is configured to deliver the iodine vapor to the plasma generator. A feedback control subsystem is responsive to one or more of plasma generator discharge current, the pressure of the iodine vapor, and/or the temperature of the iodine vapor configured to regulate the flow rate of the iodine vapor to the plasma generator.

Abstract: A liquid degasser for a space device including a gas permeable material configured for contact with a flow of liquid to be de-gassed on one side and a vacuum on the other side, and wherein the gas permeable material allows gas in the liquid to diffuse to the vacuum to remove the gas from the liquid.

Abstract: A Hall thruster with a shared magnetic structure including a plurality of plasma accelerators each including an anode and a discharge zone for providing plasma discharge. An electrical circuit having one or more cathodes connected to the plurality of plasma accelerators emits electrons that are attracted to the anode in each of the plasma accelerators. A shared magnetic circuit structure establishes a transverse magnetic field in each of the plurality of plasma accelerators that creates an impedance to the flow of electrons toward the anode in each of the plurality of plasma accelerators and enables ionization of a gas moving through one or more of the plurality of plasma accelerators. The impedance localizes an axial electric field in the plurality of plasma accelerators for accelerating ionized gas through the one or more of the plurality of plasma accelerators to create thrust.

Abstract: An air/atmosphere breathing electrically powered Hall effect thruster including a thruster duct having an inlet, an exit, and a discharge zone between the inlet and the exit for receiving air from the inlet into the discharge zone, an electrical circuit having a cathode for emitting electrons and an anode in the discharge zone for attracting the electrons from the cathode through the exit, and a magnetic circuit for establishing a magnetic field in the discharge zone radially across the duct between the anode and exit which creates an impedance to the flow of electrons toward the anode and enables ionization of the air/atmosphere moving through the discharge zone and which creates an axial electric field in the duct for accelerating ionized air/atmosphere through the exit to create thrust.