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 passive resonant bidirectional converter system that transports energy across a galvanic barrier includes a converter using at least first and second converter sections, each section including a pair of transfer terminals, a center tapped winding; a chopper circuit interconnected between the center tapped winding and one of the transfer terminals; an inductance feed winding interconnected between the other of the transfer terminals and the center tap and a resonant tank circuit including at least the inductance of the center tap winding and the parasitic capacitance of the chopper circuit for operating the converter section at resonance; the center tapped windings of the first and second converter sections being disposed on a first common winding core and the inductance feed windings of the first and second converter sections being disposed on a second common winding core for automatically synchronizing the resonant oscillation of the first and second converter sections and transferring energy between the c

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: A passive resonant bidirectional converter system that transports energy across a galvanic barrier includes a converter using at least first and second converter sections, each section including a pair of transfer terminals, a center tapped winding; a chopper circuit interconnected between the center tapped winding and one of the transfer terminals; an inductance feed winding interconnected between the other of the transfer terminals and the center tap and a resonant tank circuit including at least the inductance of the center tap winding and the parasitic capacitance of the chopper circuit for operating the converter section at resonance; the center tapped windings of the first and second converter sections being disposed on a first common winding core and the inductance feed windings of the first and second converter sections being disposed on a second common winding core for automatically synchronizing the resonant oscillation of the first and second converter sections and transferring energy between the c

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 multi-functional power supply system for a Hall thruster including a thruster assembly for providing a plasma discharge and a cathode assembly for providing electrons. The cathode assembly includes an emitter, a keeper with a current limiting device, and a heater. A magnetic field source is operatively associated with the cathode assembly for generating a magnetic field to control the discharge. A plasma discharge circuit creates a plasma and accelerates the plasma to produce thrust. A power supply is connected to the keeper and the plasma discharge circuit and is connected to the heater through a switching device responsive to a predetermined condition for interrupting the power to the heater and simultaneously enabling the power supply to deliver power to the keeper and the plasma discharge circuit to initiate production of thrust.

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: This invention features a combined radio frequency (RF) and Hall Effect ion source and plasma accelerator system including a plasma accelerator having an anode and a discharge zone, the plasma accelerator for providing plasma discharge. A gas distributor introduces a gas into the plasma accelerator. A cathode emits electrons attracted to the anode for ionizing the gas and neutralizing ion flux emitted from the plasma accelerator. An electrical circuit coupled between the anode and the cathode having a DC power source provides DC voltage. A magnetic circuit structure including a magnetic field source establishes a transverse magnetic field in the plasma accelerator that creates an impedance to the flow of the electrons toward the anode to enhance ionization of the gas to create plasma and which in combination with the electric circuit establishes an axial electric field in the plasma accelerator.

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.

Abstract: A pulsed Hall thruster system includes a Hall thruster having an electron source, a magnetic circuit, and a discharge chamber; a power processing unit for firing the Hall thruster to generate a discharge; a propellant storage and delivery system for providing propellant to the discharge chamber and a control unit for defining a pulse duration &tgr;<0.1d3&rgr;/{dot over (m)}, where d is the characteristic size of the thruster, &rgr; is the propellant density at standard conditions, and {dot over (m)} is the propellant mass flow rate for operating either the power processing unit to provide to the Hall thruster a power pulse of a pre-selected duration, &tgr;, or operating the propellant storage and delivery system to provide a propellant flow pulse of duration, &tgr;, or providing both as pulses, synchronized to arrive coincidentally at the discharge chamber to enable the Hall thruster to produce a discreet output impulse.