A propulsion system for a spacecraft includes a thrust generator for producing thrust to move the spacecraft. A propellant storage unit is in fluid communication with the thrust generator. A control assembly is in communication with the spacecraft. The control assembly includes a propellant management assembly configured to adjust a supply of propellant from the storage unit to the thrust generator. A controller is configured to control the propellant management assembly. The control assembly is configured to selectively operate the thrust generator in a first mode in which the thrust generator uses propellant to electrostatically generate thrust, and a second mode in which the thrust generator uses propellant to gas-dynamically generate thrust.

A time average peak value of low frequency magnetic noise or low frequency conductive noise generated from a power supply device which drives a Hall thruster is suppressed without mass of a satellite significantly increased. A pulse width control circuit (22) of a Hall thruster power supply device (10) outputs a spread signal (58) obtained by performing spread spectrum on a pulse signal based on a control signal (54). A voltage output circuit (21) outputs output voltage (52) to a Hall thruster (50) in accordance with the spread signal (58) output by the pulse width control circuit (22).

A neutralizer suitable for use in an ion engine comprises a halogen gas source and an electrode tube comprising an inlet opening connected to the halogen gas source for supplying a halogen gas provided by the halogen gas source into the electrode tube, a discharge space for generating a plasma from the halogen gas supplied into the electrode tube, and an outlet opening for discharging the plasma generated in the discharge space and free electrons from the electrode tube. An electron emitter is arranged in the discharge space of the electrode tube, which is at least partially made of tungsten, a tungsten alloy or a tungsten composite material containing at least one of iridium, rhenium, ruthenium, rhodium and osmium.

A pulsed metal plasma thruster (MPT) cube has a plurality of thrusters, each having a first cathode electrode and a trigger electrode separated from the first electrode by an insulator sufficient to support an initiation plasma, and a porous anode electrode positioned a separation distance from the face of all of the cathode electrodes. The cathode electrode can be either the inner electrode or the outer electrode. A power supply delivers a high voltage pulse to the trigger electrode with respect to the cathode electrode sufficient to initiate a plasma on the surface of the insulator. The plasma transfers between the anode electrode and cathode electrode of selected thrusters, thereby generating a pulse of thrust.

A satellite having a cooling system to remove heat from an electric rocket engine using a working fluid. The cooling system can include a pump that circulates working fluid along a cooling loop between the rocket engine and a radiator. The cooling system can also utilize thermoacoustic, Stirling refrigeration, and/or heat pipe techniques. One or more reservoirs can be provided to store the working fluid, and in some forms a secondary reservoir can be provided to aid in management of a center of mass of the satellite. A fluid reaction loop can be provided in which working fluid is accelerated to impart a torque on the satellite. In some forms, the working fluid can be utilized as both a coolant and a propellant for the rocket engine. The electric rocket thruster can also include one or more internal pathways for the conveyance of working fluid.

A satellite propulsion system and methods of operating the same include a first ionization stage and a second acceleration stage. The first ionization stage has a plasma source configured to produce an arc discharge and emit a preliminary plasma. The plasma source includes an external magnetic field configured to magnetize the arc discharge. The second acceleration stage has an accelerator positioned in series with the plasma source. The accelerator is configured to accelerate the preliminary plasma out through the accelerator, thereby creating an accelerated plasma flow. The application of an activation threshold voltage to the accelerator results in a surge in system performance parameters.

A satellite thruster increases satellite efficiency. The Linear Actuated μCAT has a stepper motor to move the ablative electrode forward. A LabVIEW program and Arduino microcontroller are used to analyze the Linear Actuated μCAT to determine how many steps are required for re-ignition, arc current, and the validity of the feed system. Results from testing show that micro-stepping the stepper motor is an effective way to replenish the cannibalized electrode for propellant.

An ion accelerator includes: an inner magnet having a channel extending through it in an axial direction; an outer magnet extending around the inner magnet, the magnets having like polarities so as to produce a magnetic field having two locations of zero magnetic field strength. The locations are spaced apart in the axial direction; and an anode and a cathode are arranged to generate an electrical potential difference between the locations.

A hollow cathode apparatus includes an outer tubular dielectric barrier circumferentially surrounding an outer tubular surface of the cathode tube, the outer tubular dielectric barrier being composed of a barrier material which is electrically non-conductive. Also disclosed is a system comprising the hollow cathode apparatus, an anode which is spaced from the output end of the tubular cathode, and electrical circuitry connected between the cathode tube and the anode for connection to a source of electrical power for providing an electrical potential between the cathode and anode to cause an electric current to pass from the emitter into the input gas to form a plasma which is then output through the output end of the cathode tube to form a plasma plume. The electrical circuitry comprises: a first power supply for connecting the cathode and the cathode electrode to a first source of DC power in an ignition power mode, wherein the first power supply comprises a current control device which is adapted to control the current between the cathode and the cathode electrode, wherein the current control device is arranged to function as an anti-surge current stabiliser; and a second power supply for connecting the anode and the cathode to a second source of DC power in a steady state power mode.

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.