A thrust generator is provided for producing thrust to move a spacecraft. The thrust generator includes a housing having a first end and an opposing second end. The first end is associated with a mount for coupling to the spacecraft. The housing further defines a central axis extending through the first end and the second end. The second end defines an annular propulsion outlet. At least one nozzle is positioned proximate the second end. The thrust generator is selectively operable in a first mode in which the thrust generator uses propellant to electrostatically generate thrust via the annular propulsion outlet, and a second mode in which the thrust generator uses propellant to gas-dynamically generate thrust via the at least one nozzle.

An electrothermal plasma production device is presented. The plasma production device includes: a plasma production chamber; an RF antenna external to the plasma production chamber; a propellant tank and flow regulator external to the plasma production chamber and in communication with the plasma production chamber; and a plenum disposed between the propellant tank and the plasma production chamber. The RF antenna, in combination with an AC power source, is configured to provide an RF energy to an interior region of the plasma production chamber and to an interior region of the plenum with sufficient power to ionize at least some of the propellant in the plenum. The plasma production chamber is configured to include a propellant injector for receiving propellant at a first closed end of the plasma production chamber.

Methods and systems for electric propulsion are provided. An example method includes providing a magnetic shield using an accelerating channel made of a soft magnetic material; generating, by a magnetic system, a radial magnetic field in the accelerating channel to ionize a working substance, wherein the magnetic system includes a central magnetic pole, an outer annular pole, a magnetic circuit, and coils to carry an electrical current; and generating, using an outer hollow cathode and an anode-gas distributor disposed within the accelerating channel, an electrical discharge along the accelerating channel. The accelerating channel provides the magnetic shield to force the radial magnetic field to have a maximum gradient at a location of the central magnetic pole and at a location of the outer annular pole and to force ions of a working substance to pass isolators of magnetic poles, thereby decreasing erosion of the isolators.

A Hall-effect thruster assembly includes a plurality of magnetic sources for creating a magnetic circuit. The plurality of magnetic sources are positioned between a first end and a second, opposite end of the Hall-effect thruster. The plurality of magnetic sources define a longitudinal axis extending through the first end and the second end. The first end is configured as a discharge end. A mount assembly is coupled to the second end. The mount assembly is configured to secure the plurality of magnetic sources to a spacecraft. A magnetic element is supported by the mount assembly. The magnetic element is positioned relative to the plurality of magnetic sources by the mount assembly.

Methods and apparatuses for emitting electrons from a hollow cathode are provided. The cathode includes a plasma holding region configured to hold a plasma, a gas supply source configured to supply gas to the plasma holding region, and an orifice plate disposed on a periphery of the plasma holding region. The orifice plate comprises a plurality of openings constructed to receive electrons from the plasma. The plurality of openings decouple gas conductance and electrical conductance across the orifice plate. The diameters of the plurality of openings are within a range of 20%-60%, inclusive, of a diameter of a circular opening with an area equal to a sum of the areas of the plurality of openings.

A Hall thruster includes an annular discharge region and an annular cathode concentric to the annular discharge region.

A method of producing a charge separation in a plasma having a low particle density which comprises a plurality of electrons and a plurality of positive ions. The method includes generating a magnetic field and passing the plasma having a low particle density along a first axis through the magnetic field. The magnetic field is generated having a component which is perpendicular to the first axis and is configured so as to deflect the plurality of electrons from the first axis and allow the plurality of positive ions to travel substantially undeflected along the first axis. Also provided is a magnetohydrodynamic generator and a low earth orbit thruster making use of the charge separation mechanism.

Methods and systems for a discharge power supply for providing a stabilized discharge power to a Hall-effect thruster are provided. A method includes sensing, by a first sensor circuit and based on a discharge power, a voltage sense signal, sensing, by a second sensor circuit and based on the discharge power, a current sense signal, multiplying, by a multiplying circuit, the voltage sense signal and the current sense signal to generate a feedback signal, generating, by a control logic circuit and based on control signals, further control signals, generating, by an impulse generation circuit and based on the further control signals and the feedback signal, control impulses, producing, by a transistor bridge and using the control impulses and a power source, an electrical impulses, and modifying, by an output circuit, the electrical impulses to generate the stabilized discharge power.

An ion thruster is provided allowing a plasma discharge to be generated and confined in an external confinement space created by an external magnetic field B.

A low-power Hall thruster gains significantly improved efficiency by a combination of features, including a single piece, h-shaped magnetic screen which enables a more efficient internal volume utilization as well as optimal magnetic shielding; an internally mounted cathode with varying diameter further decreases the footprint of the thruster; an anode with multiple baffles connected by axially oriented holes generates a highly azimuthally uniform propellant flow.