Embodiments relate to a hallow cathode with integral layers of radiation shielding. The hollow cathode includes an inner cathode tube that forms a gas feed to direct gas toward a downstream end, where the directed gas forms plasma. A heater element is positioned at the downstream end of the inner cathode tube, the heater element to heat the plasma. The hollow cathode further includes an outer cathode tube with a keeper electrode to sustain a bias voltage across a gap at a downstream end of the outer cathode tube for igniting the plasma. The integral layers of radiation shielding are connected by offset radial supports and are incorporated as a single element with either the inner or outer cathode tube, where the integral layers are nested with torturous conductive paths to reduce radiation and conduction losses from the downstream end of the inner cathode tube.

A magnetic circuit for creating a magnetic field in a main annular ionization and acceleration channel of a Hall-effect plasma thruster, having an open top end for emitting ions and a closed bottom end, includes outer magnets comprising a bottom annular outer magnet, and a top annular outer magnet disposed above the bottom outer magnet; inner magnets comprising a bottom inner magnet, of cylindrical form having a bottom part of a diameter less than the diameter of a top part, disposed below the top outer magnet, and a top annular inner magnet disposed above the bottom inner magnet; the outer magnets having a same pole (N, S) on their respective top face and an opposite same pole (S, N) on their bottom face; the inner magnets having an orientation of their poles that is the reverse of that of the outer magnets; and the outer magnets and the inner magnets being disposed above the closed bottom end of the annular channel.

A control assembly for a spacecraft includes a propellant management assembly configured to adjust a supply of propellant from a storage unit to a thrust generator. The control assembly further includes a controller having a processor configured to receive an input from the spacecraft, and receive at least one input from the propellant management assembly or from the thrust generator. The processor is further configured to, based on the inputs, determine a desired operating mode of the thrust generator, and based on the determination, either 1) send an output to the propellant management assembly to operate in a first mode in which the thrust generator uses propellant to electrostatically generate thrust or 2) send an output to the propellant management assembly to operate in a second mode in which the thrust generator uses propellant to gas-dynamically generate thrust.

A Hall thruster is configured to reduce or eliminate pole erosion by electrically tying the cathode to the thruster chassis body. The electrical connection controls the ion energy hence reducing erosion at the pole. In a different configuration, the cathode is biased by a power supply, allowing further control of the ion energy and the elimination of pole erosion, thus increasing the thruster's operational lifetime.

A Hall effect thruster is provided having one or more components fabricated using additive manufacturing techniques. Additive manufacturing can be used to fabricate the propellant distributor and the discharge channel of the thruster. The propellant distributor can be separated from the anode of the thruster and can form the base of the discharge channel. The discharge channel can be detachably connected to the propellant distributor using one of a threaded connection or a snap-fit connection. The discharge channel can have an annular shape and electromagnets and magnetic poles can be placed in the surrounding areas of the discharge channel.

Chamber bottom for a plasma thruster making it possible to combine several functions in a single piece and, in particular, to fasten certain insulating parts of the plasma thruster, the chamber bottom having, in a single piece, a chamber bottom surface for closing an annular chamber formed by the chamber bottom and at least one insulating part attached to the chamber bottom, and at least a first set of tabs including fastening tabs for fastening the at least one insulating part to the chamber bottom.

Disclosed is a closed drift, narrow channel Hall thruster configured to operate at powers <30 W. The thruster includes a thruster body and a neutralizing cathode. The thruster body includes a magnetic circuit including a magnetic source and two magnetic poles, a metallic, annular thruster channel formed by the magnetic poles with a downstream channel width smaller than about 3 mm and an upstream channel width greater than the downstream channel width, an anode positioned at the channel's entry, and a gas distributor configured to release a propellant gas into the thruster channel. The magnetic circuit is configured to generate a magnetic field in the thruster channel for trapping electrons therein. The channel walls (the magnetic poles) are under bias potential. The anode and the cathode are configured to generate a substantially axial electric field in the thruster channel. In operation, propellant gas atoms ionized by trapped electrons in the thruster channel, accelerate axially, exiting via the channel's exit.

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.

Described herein is a power processing unit (PPU) for use with a Hall Effect Thruster (HET) and a Propellant Management Assembly (PMA) of a spacecraft. The PPU comprises an anode and ignitor supply subsystem that provides anode and ignitor signals to an anode and an ignitor circuit of the HET. The PPU also comprises a valve control subsystem that provides valve control signal(s) to valve(s) of the PMA. The anode and ignitor supply subsystem and the valve control subsystem are each coupled to a low voltage (LV) bus of an electrical power subsystem of the spacecraft. The anode and ignitor supply subsystem includes a step-up DC-DC converter having a transformer that steps-up a voltage of the LV bus to a higher voltage used to produce the anode and ignitor signals. The valve control subsystem is devoid of a transformer. An Electric Propulsion System (EPS) includes the PPU, HET and PMA.

Scalable power processing units (PPUs) for Hall-effect thrusters (HETs) and terrestrial systems are disclosed. A technique for current estimation may be employed on each output of parallel isolated discharge supply modules (DSMs) to force proper current/load sharing between the DSMs. A flyback power supply may be used that performs the dual functions of a cathode keeper plasma ignitor and sustainer. The flyback power supply may be tuned for a high no-load direct current (DC) output voltage to achieve cathode keeper ignition rather than requiring a separate ignitor supply, which reduces circuit complexity. To address requirements for higher voltage DC ignition than are achievable with a flyback power supply alone, a supplemental DC ignitor may be placed in parallel with the flyback power supply of some embodiments. Such simplified PPU architectures may provide a high efficiency, low part count, scalable architecture suitable for more compact and lower cost system designs.