Abstract: A conduit is placed between a vacuum system and the open air or other gaseous environment. A laser or other excitation source is used to ionize the air on the air-side of the conduit. An axial applied electric field is used to repel positive ions from traversing the tube and reaching the region of the vacuum. Electrons are collected in the vacuum region and disposed of using a Faraday cup. The repelled ions assist in creating a counter pressure to sweep neutral atoms out of the tube and back into the ambient air. As a result, a hollow tube can connect an evacuated volume to the open air without compromising the vacuum. This is a “windowless window.” An array of such tubes can be assembled together to increase the area of the aperture.

Abstract: An intake system for an atmosphere-breathing electric thruster is disclosed, comprising an inlet for inflow of atmosphere particles, an outlet for coupling to the thruster for fueling collected atmosphere particles to the thruster, a collector arranged between the inlet and the outlet comprising multiple channels for allowing inflowing atmosphere particles to pass through the channels towards the outlet, the channels defining an inlet area and a length, wherein a position of at least part of the channels is adjustable to alter at least one of the inlet area and the length.

Abstract: An inductive plasma acceleration apparatus, comprising a pulse laser assembly, a pulsed discharge assembly, an exciting coil assembly, a solid-state working medium, and a control assembly; the exciting coil assembly is electrically connected to the pulsed discharge assembly such that a strong pulse current is produced in the exciting coil assembly during the discharge process of the pulse discharge assembly, and an inductive pulse electromagnetic field is excited around the exciting coil assembly; the solid-state working medium is positioned on the optical path of a pulse laser emitted by the pulse laser assembly such that the solid-state working medium produces a pulse gas under the ablation action of the pulse laser, and the inductive pulse electromagnetic field is positioned on the circulation gas path of the pulse gas such that the pulse gas can enter the inductive pulse electromagnetic field.

Abstract: A vacuum arc thruster with multi-layer insulation includes a housing, an anode unit and a cathode unit spaced apart from each other in the housing, and an insulator disposed between the anode unit and the cathode unit. The insulator includes a plurality of fuel layers and a plurality of insulating layers. Each insulating layer is located between every two adjacent fuel layers. Accordingly, a multiple-layer design is formed by arranging the fuel layers and the insulating layers which are made of different materials in an alternating manner, thereby attaining the maximum field emission effect, increasing the stability and efficacy of operating the vacuum arc thruster, and prolonging the service life of the thruster.

Abstract: An apparatus generates energetic particles and generates a plasma of a vaporized solid material and gaseous precursors for the application of coatings to surfaces of a substrate by way of condensation of plasma and for electric propulsion applications.

Abstract: In an aspect of the invention there is provided a plasma thruster device comprising: an electrically insulating substrate, said substrate comprising one or more feed channels for feeding an electrically conductive liquid to a bridge structure; said substrate further provided with electrical terminals; said bridge structure configured to form, when provided with the electrically conductive liquid, an electrical conducting bridge; said bridge structure configured to form contact areas in electrical contact with said electrical terminals, said bridge structure thereby connecting the contact areas, said bridge structure arranged for forming a plasma of said electrically conductive liquid, when the electrically conductive liquid is ionized by a current peak flow circuit that contacts the contact areas via said electrical terminals.

Abstract: 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.

Abstract: High propellant throughput Hall-effect thrusters (HETs) and components thereof are disclosed. A compact and high propellant throughput HET has an improved magnetic circuit that mostly shields the discharge chamber walls from high-energy ionized propellant, low-profile sacrificial pole covers to delay magnetic pole erosion, a unique discharge chamber subassembly, a mechanically crimped cathode emitter retainer to increase efficiency, a center-mounted hollow cathode, or a combination thereof. Such feature(s) may balance propellant throughput and thruster performance, minimize the volume of the thruster envelope, and/or simplify the thruster assembly.

Abstract: A narrow channel Hall thruster comprising a thruster body with a magnetic circuit, an annular thruster channel having a channel width of less than 3 mm formed within the magnetic circuit, an annular anode, a cathode positioned externally to the thruster, and configured for electron emission, a power supply applying a positive potential to the anode, such that a plasma discharge can be generated in the annular thruster channel, and another power supply applying a negative potential to the cathode, relative to the thruster body and the anode. The second power supply reduces its negative voltage output to the cathode when the current supplied by the anode power supply exceeds a predetermined level, indicating that the discharge has reached a stable initiated condition. The reduction of the voltage output of the second power supply can be achieved either by self-regulation, or by use of a current limit circuit.

Abstract: Provided is an apparatus for generating electricity, mechanical energy, and/or process and district heat using a gas propellant chamber fueled with fissile material and enclosed in a sealed containment vessel which also contains an operating gas. The system allows for the operating gas to be compressed as it enters the nuclear fuel chamber where it is heated. As the operating gas exits the nuclear fuel chamber, the kinetic energy of the gas is converted to rotational energy by a variety of methods. The rotational energy is further converted to electricity, mechanical energy, and/or process and district heat. The operating gas circulates in the containment vessel and is cooled prior to re-entering the gas propellant chamber. The apparatus thereby provides a simpler and safer design that is both scalable and adaptable. The apparatus is easily and safely transportable and can be designed to be highly nuclear-proliferation-resistant.

Abstract: Provided herein are various leptonic power sources, leptonic control systems, and leptonic-powered engines. In one example, an apparatus includes a housing having apertures through which material can enter and exit, and an anode coupled to the housing upstream from a cathode. A leptonic source emits beam electrons into the housing to ionize the material into a plasma according to a selectable ionization degree and deposit charge onto the cathode to establish an electric field in the plasma. A magnetic field source produces a magnetic field in the plasma at selectable angle to the flow of the plasma to at least partially entrain plasma electrons. Ions of the plasma are accelerated downstream in the housing by the electric field and impart momentum to a portion of the material to produce a thrust proportional to the selectable ionization degree of the plasma and a selectable intensity of the electric field.

Abstract: A modular micro-cathode arc thruster for use in satellites. An exemplary satellite has a plurality of stacked modular arc thrusters, each having an external anode, an internal cathode, and an insulator therebetween. The arc thrusters are situated in a housing, wherein the housing has an opening to eject exhausted thrusters. Once an arc thruster is expended, the push rod ejects that arc thruster and the next arc thruster takes its place.

Abstract: A blower including a duct configured to allow air to flow in and out and a plurality of blades disposed to be parallel to the duct. Each of the blades including a first part, a second part, and an airflow generator configured to generate airflow in a direction from the inlet to the outlet by applying a voltage between the first electrode and the second electrode which are disposed between a first electrode on a side of the inlet, a second electrode on a side of the outlet, and a dielectric. In a cross section of the blade in the airflow direction when cut in a cross section perpendicular to each of the blades, the first part has a thickness decreasing in a direction toward the inlet and the second part has a thickness decreasing in a direction toward the outlet.

Abstract: Spacecraft thruster systems are disclosed. In some instances, a spacecraft thruster system may include stacked ion thrusters and/or ion thruster layers. The ion thrusters and/or ion thruster layers may be sequentially activated and jettisoned from the thruster system after use.

Abstract: The present disclosure describes systems and methods for using an ionizing fluidic accelerator that may encompass the use of an ionizing fluidic accelerator including a substrate, an electron emitter having a negative bias and being formed on the substrate, an anode having a positive bias and being formed on the substrate, and an attractor having a negative bias and being formed on the substrate. The electron emitter and the anode may be separated in a first direction and the negative bias of the electron emitter and the positive bias of the anode may produce a first electric field in the first direction. The anode and the attractor may be separated in a second direction, the positive bias of the anode and the negative bias of the attractor may produce a second electric field in the second direction, and the second direction may be orthogonal to the first direction.

Abstract: An ion powered assembly includes a collector assembly and an emitter assembly, comprising a plurality of conductive emitter wires supported by the emitter wire support structure. A control circuit is operatively connected to at least the emitter and collector assemblies and includes a power supply configured to provide voltage to the emitter and collector assemblies.

Abstract: An electric thruster comprises a propellant delivery system, wherein the propellant delivery system comprises: a pipe for carrying propellant; a valve which is adapted to adjust a volume or mass flow of the propellant in the pipe; and an expansion actuator which is adapted to actuate the valve for adjusting the volume or mass flow of the propellant. The electric thruster further comprises at least one tank which is adapted to receive propellant for the electric thruster; and a discharge chamber. The at least one tank thereby at least partially encloses an end of the discharge chamber and/or an element thermally coupled with the discharge chamber, and the valve of the propellant delivery system is arranged between the tank and the end of the discharge chamber.

Abstract: A thruster for a micro-satellite is disclosed. The thruster includes a cathode composed of a propellant material and an anode composed of ablative material. The thruster includes a housing having a proximate end and an opposite distal end having a thrust channel. The housing holds the anode and the cathode. A pulsed voltage source is coupled between the cathode and the anode causing current sufficient to create ablation of the anode and a plasma jet including ablated particles from the anode to be emitted from the thrust channel.

Abstract: The dipole drive is a new propulsion system which uses ambient space plasma as propellant, thereby avoiding the need to carry any of its own. The dipole drive is constructed from two parallel screens, one charged positive, the other negative, creating an electric field between them with no significant field outside. Ambient solar wind protons entering the dipole drive field from the negative screen side are reflected out, with the angle of incidence equaling the angle of reflection, thereby providing lift if the screen is placed at an angle to the plasma wind. Protons entering from the positive side are accelerated out the negative screen, producing thrust. The dipole drive can achieve more than 3 mN/kWe in interplanetary space and better than 10 mN/kWe in Earth, Venus, Mars, or Jupiter orbit and offers potential as a means of achieving ultra-high velocities necessary for interstellar flight.

Abstract: The invention relates to an ion thruster, comprising: a chamber, a reservoir, comprising a solid propellant (PS), housed in the chamber and comprising a conductive jacket provided with an orifice; means for forming an ion-electron plasma in the chamber, which means are able to sublime the solid propellant in the reservoir, then to generate said plasma in the chamber from the sublimed propellant coming from the reservoir through the orifice; a means for extracting and accelerating the ions and electrons of the plasma out of the chamber, which means comprises at least two grids at one end (E) of the chamber; a radiofrequency AC voltage source for generating a radiofrequency signal comprised between the plasma frequencies of the ions and of the electrons, arranged in series with a capacitor and connected, by one of its outputs and via this capacitor, to one of the grids, with the other grid being connected to the other output of said voltage source; said means for extracting and accelerating and said voltage

Abstract: Various examples related to a deployable gridded ion thruster are described. A deployable gridded ion thruster can include: a thruster body including an ion generating unit; and an expandable discharge chamber configured to expand from a stored configuration to a deployed configuration. The expandable discharge chamber can include a chamber wall having a first geometric shape compressed within the thruster body when in the stored configuration and a second geometric shape expanded outward from the thruster body when in the deployed configuration. Also described herein are methods of operation for a deployable gridded ion thruster.

Abstract: Systems and methods establish plasma in a rotating magnetic field. An exemplary embodiment is a plasma thruster that establishes a first transverse magnetic field with respect to a system axis of a plasma propulsion system; establishes a second transverse magnetic field oriented orthogonally to the first transverse magnetic field, wherein the second transverse magnetic field is out of phase with the first transverse magnetic field; and establishes a magnetic field aligned with the system axis using a plurality of magnet elements oriented along the system axis. A plasma containment portion defines an interior region, wherein an interior region of a plasma containment portion accommodates a plasma that is established by a rotating magnetic field component that is cooperatively established by the first transverse magnetic field and the second transverse magnetic field, and wherein the plasma is accelerated out of the plasma containment portion by magnetic forces to generate a propulsion force.

Abstract: The monofilament vaporization propulsion system in accordance with an embodiment of the invention includes a mechanical feed, an elongated barrel, a heater block, a tube, and a nozzle. A monofilament solid propellant is wound around a spool and fed into the mechanical feed. The elongated barrel is configured to receive the solid propellant towards a second end. The heater block is positioned near the second end of the barrel and configured to heat the propellant into a liquid propellant as the solid propellant moves towards the second end. The tube receives the liquid propellant and is configured to evaporate the liquid propellant into a gaseous propellant. The gaseous propellant enters a nozzle in communication with the tube. The gaseous propellant being fed into the nozzle entrance expands there-through to create propulsion out an nozzle exit.

Abstract: An electric power supply system for a Hall effect electric thruster. The Hall effect electric thruster includes an anode, a cathode, a heater for the cathode and an igniter. The electric power supply system includes a first power supply source to power the anode, a second power supply source to power the heater and a power supply unit to electrically supply the igniter. The power supply unit includes a third power supply source and a passive electric circuit. The third power supply source powers the passive electric circuit and is configured to generate a voltage in the form of at least one pulse.

Abstract: A flow rate regulator device is provided, including an upstream chamber, a downstream chamber, a plurality of electrically conductive capillary ducts providing parallel fluid flow connections between the upstream chamber and the downstream chamber, first and second electrical terminals configured to be connected to an electric current source, and at least one electric switch configured to connect one or more of the capillary ducts selectively between the electrical terminals. A system for feeding propellant gas to a space electric thruster is also provided, including at least one such flow rate regulator device to regulate a propellant gas flow rate. And, a flow rate regulation method is provided, using the flow rate regulator device.

Abstract: 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.

Abstract: A capacitive wireless charging system having a charging circuit and the operating characteristics of the charging circuit can be adjusted. The charging circuit includes two coupling capacitors formed by two electrode plates at least partially overlapping two other electrode plates, where the coupling characteristics of the coupling capacitors can be adjusted by moving at least one of the electrodes. When the coupling characteristics of the coupling capacitors reach a pre-determined threshold, the operating characteristics of the charging circuit can be adjusted to optimize the power transfer efficiency of the capacitive wireless charging system.

Abstract: A control system comprises sources of supply, in terms of power and in terms of control signals, capable of equally piloting each of the electric thrusters and further comprises a switching device capable of linking any one of the sources of supply to any one of the electric thrusters. The switching device comprises a rotary main roller divided into a number of angular segments comprising input and output conductive tracks and pre-wired electrical networks linking the input conductive tracks to the output conductive tracks of each angular segment, the pre-wired electrical networks associated with the different angular segments all being different and dedicated to different configurations for the piloting of the electric thrusters by the sources of supply.

Abstract: Micro-emitter arrays and methods of microfabricating such emitter arrays are provided. The microfabricated emitter arrays incorporate a plurality of emitters with heights greater than 280 microns with uniformity of +/?10 microns arranged on a supporting silicon substrate, each emitter comprising an elongated body extending from the top surface of the substrate and incorporating at least one emitter tip on the distal end of the elongated body thereof. The emitters may be disposed on the substrate in an ordered array in an X by Y grid pattern, wherein X and Y can be any number greater than zero. The micro-emitter arrays may utilize a LMIS propellant source including, for example, gallium, indium, bismuth, or tin. The substrate may incorporate at least one through-via providing a fluid pathway for the LMIS propellant to flow from a propellant reservoir beneath the substrate to the top substrate surface whereupon the micro-emitter array is disposed.

Abstract: A microthruster system may include a substrate and a source film. The substrate may include a plurality of emitter tips, and a source film deposited on the substrate. The source film may include silver. The microthruster system may also include a solid electrolyte film, which may include chalcogenide film, deposited over the source film. The solid electrolyte film may cause ions of the source film to move to the plurality of emitter tips.

Abstract: An ion source includes a chamber. The ion source further includes a first hollow cathode having a first hollow cathode cavity and a first plasma exit orifice and a second hollow cathode having a second hollow cathode cavity and a second plasma exit orifice. The first and second hollow cathodes are disposed adjacently in the chamber. The ion source further includes a first ion accelerator between and in communication with the first plasma exit orifice and the chamber. The first ion accelerator forms a first ion acceleration cavity. The ion source further includes a second ion accelerator between and in communication with the second plasma orifice and the chamber. The second ion accelerator forms a second ion acceleration cavity. The first hollow cathode and the second hollow cathode are configured to alternatively function as electrode and counter-electrode to generate a plasma.

Abstract: A discharge chamber of an ion drive, an ion drive having a discharge chamber, and a diaphragm for being affixed in a discharge chamber of an ion drive. The discharge chamber comprises a diaphragm, wherein the diaphragm of the discharge chamber comprises a magnet and is disposed and/or affixed in the discharge chamber.

Abstract: An ion source device for producing an ion beam may include a housing having an opening, a first electrode, and a second electrode. A portion of the first electrode and the second electrode may be located within the housing. The first electrode may have a first side facing the opening and may be configured to provide an electric field toward the opening. The second electrode may be configured to provide an electron presence between the first electrode and the opening at least at times when the first electrode is not providing the first electric field. The ion source device may include a magnet and may produce a magnetic field generally perpendicular to the electric field provided by the first electrode. The ion source device may provide an ion beam with low turn on delay, which may be on the order of one microsecond or less, and low turn on jitter.

Abstract: A system and method provides a fault-tolerant multi-channel pulsed plasma thruster system utilizing a control unit and an embedded real time application manipulating low-level timing events with programming, with clear examples of completely flexible control techniques of a scalable micropropulsion system having many pulsed plasma thruster channels, taking into account system aging behavior and specific mission utilization requirements that may change in the mission lifetime. The system and method also covers an architecture lending itself suitable for design of a dedicated FGPA or ASIC that would tightly integrate many channels of thruster components to build a robust, resilient and versatile micropropulsion subsystem for space applications, and indirectly for advanced multi-channel spacecraft instrumentation.

Abstract: A Hall thruster apparatus having walls constructed from a conductive material, such as graphite, and having magnetic shielding of the walls from the ionized plasma has been demonstrated to operate with nearly the same efficiency as a conventional nonmagnetically shielded design using insulators as wall components. The new design is believed to provide the potential of higher power and uniform operation over the operating life of a thruster device.

Abstract: A fuel-free spacecraft propelling system having an open-ended outer cylinder of a propelling device and an atomic oxygen collecting device is disclosed. The latter is arranged at the forwardly-propelled front end of the outer cylinder and is hermetically connected with an RF generating device and an ion cyclotron wave heating device through a magnetic confinement device. A spiral wave discharge oxygen plasma inlet and a spiral wave discharge oxygen plasma outlet in the ion cyclotron wave heating device are respectively provided with another magnetic confinement device. The propulsion of the invention does not need to carry the propellant, which greatly reduces the launch costs, and enables a spacecraft to advantageously have an increased orbit life over existing spacecraft systems.

Abstract: A control system for controlling the operation of a plurality of micro thrusters arranged in a plurality of parallel horizontal rows and a plurality of parallel vertical columns, the control system requires a power source, a first plurality of power lines connected to the power source and coupled to at least one micro thruster of the plurality of micro thrusters in a horizontal row of the plurality of parallel horizontal rows, a second plurality of power lines connected to the power source and coupled to at least one micro thruster of the plurality of micro thrusters in a vertical column of the plurality of parallel vertical columns, and a control unit coupled to the power source to control activation of the first plurality of power lines and activation of the second plurality of power lines.

Abstract: A plasma motor for extracting a positive ion flow has a single ionization stage and a device for supplying the ionization stage with an ionizable electronegative gas. The plasma motor further has a device for creating an electric field so as to produce the ionization of the gas in the ionization stage. The device for creating the electric filed includes a device for extracting a negative ion flow and, a device for extracting a positive ion flow, connected to the ionization stage. The extraction of a positive ion flow and the extraction of a negative ion flow are of the same amplitude, ensuring the electrical neutrality of the motor. The extraction of a positive ion flow and the extraction of a negative ion flow allow the neutrality of the motor to be ensured.

Abstract: A system and apparatus for controlled fusion in a field reversed configuration (FRC) magnetic topology and conversion of fusion product energies directly to electric power. Preferably, plasma ions are magnetically confined in the FRC while plasma electrons are electrostatically confined in a deep energy well, created by tuning an externally applied magnetic field. In this configuration, ions and electrons may have adequate density and temperature so that upon collisions they are fused together by the nuclear force, thus forming fusion products that emerge in the form of an annular beam. Energy is removed from the fusion product ions as they spiral past electrodes of an inverse cyclotron converter. Advantageously, the fusion fuel plasmas that can be used with the present confinement and energy conversion system include advanced (aneutronic) fuels.

Abstract: Ion optics for use in a conventional or annular or other shaped ion thruster are disclosed including a plurality of planar, spaced apart ion optic electrode pairs sized to include a diameter smaller than the diameter of thruster exhaust and retained in, on or otherwise associated with a frame across the thruster exhaust. An electrical connection may be provided for establishing electrical connectivity among a set of first upstream electrodes and an electrical connection may be provided for establishing electrical connectivity among the second downstream electrodes.

Abstract: An electric propulsion system includes a first stationary plasma thruster including a single first cathode, a first anode, and a first gas manifold, and a second stationary plasma thruster including a single second cathode, a second anode, and a second gas manifold. The system further includes an electrical connection device common to the first and second cathodes, first and second gas flow rate control devices with a common fluid flow device for feeding gas, and a selective control device for activating at any given instant only one of the first and second cathodes in co-operation with one or the other of the first and second anodes.

Abstract: A Hall thruster apparatus having walls constructed from a conductive material, such as graphite, and having magnetic shielding of the walls from the ionized plasma has been demonstrated to operate with nearly the same efficiency as a conventional non-magnetically shielded design using insulators as wall components. The new design is believed to provide the potential of higher power and uniform operation over the operating life of a thruster device.

Abstract: A heating element that includes a ceramic material doped with various elements is described. The heating element can be heated by forcing a fuel to flow through the ceramic material, where the fuel interacts with the dopants. The interaction can produce energy in the form of heat. Inventive aspects of the present material include apparatus and methods for modulation of the heat energy, physical features providing for an increase in the rate of heat release, optimization of materials and material morphology for quantity and efficiency of heat release and provision for fueling and maintenance.

Abstract: A chemical-electromagnetic hybrid propeller with variable specific impulse. Fuel gas ejected out from a spraying tube of the chemical propeller through chemical propulsion enters an ionization chamber through a first magnetic mirror tube for ionization. The fuel gas after ionization is heated up by radio-frequency ion cyclotron waves in an ion cyclotron wave heating chamber so as to improve the kinetic energy. Then a second magnetic mirror tube is used, so that ions in the fuel gas after the ionization are heated up many times in a reciprocating manner between the magnetic mirror tubes, and ejected to generate forward propulsion force. By means of the propeller, the propulsion force and the specific impulse are greatly increased.

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 plasma drive includes a plurality of plasma thrusters arrayed in each of at least one array of plasma thrusters. Plasma thrust may be generated sequentially or in a pulse from each array. Circuitry is adapted to selectively fire each thruster in each array according to a digitally controlled progression. The controlled firing progression collectively provides a cumulative thrust vector for each array. In a turbine drive embodiment the controlled progression causes sequential firing of the thrusters in each array, and the arrays in sequence. The controlled progression allows for directional control of the combined cumulative thrust vectors.

Abstract: A rocket having a motor with a user adjustable thrust is provided. The rocket includes a main cylinder containing a rocket propellant, the propellant configured to generate gas during operation and one or more nozzles arranged to direct the gas in a first direction. A thrust adjustment device is arranged to receive a portion of the gas, the thrust adjustment device configured to change the direction of flow of at least a portion of the gas.

Abstract: An electric propulsion machine includes an ion thruster having a discharge chamber housing a large surface area anode. The ion thruster includes flat annular ion optics with a small span to gap ratio. Optionally, at least a second thruster may be disposed radially offset from the ion thruster.

Abstract: An electro-hydrodynamic system that extracts energy from a gas stream, which includes an injector that injects a first species of particles having the same polarity into the gas stream, wherein particle movement with the gas stream is opposed by a first electric field; an electric field generator that generates a second electric field opposing the first, such that the net electric field at a predetermined distance downstream from the injector is approximately zero; an upstream collector that collects a second species of particles having a polarity opposite the first particle species; a downstream collector that collects the charged particle; and a load coupled between the downstream collector and the upstream collector, wherein the load converts the kinetic energy of the gas stream into electric power.

Abstract: A field-ionization based electrical ion thruster utilizes a single propellant that can be used in either a high specific-impulse mode, i.e., ion-thruster mode, or a low-specific-impulse mode, i.e., a cold-gas thruster mode. In one embodiment, the high specific impulse mode (ion thruster mode) utilizes a miniaturized positive-ion field-ionization chamber including a permeable substrate infused with properly oriented carbon nanotubes (CNTs), which is fed propellant from a porous injection plug made from permeable carbon or equivalent material. In one embodiment, field-electron emission from a neutralizer, such as a carbon nanotube array neutralizer, positioned after one or more accelerator grids is used for ion neutralization. In one embodiment, the low specific-impulse (cold-gas mode) uses a conventional supersonic nozzle-expansion to generate thrust.