An electrospray emitter can include an emitter structure connected to a reservoir containing a working material in electrical communication with a first electrode and an electrode separated from an apex of the emitter structure by a distance, wherein a surface of the grid electrode proximal the emitter structure comprises at least one coating.

A polarity-selectable high voltage direct current power supply including a first drive assembly that transforms a first low voltage DC input into a first medium voltage alternating current output; a first HV output assembly that transforms the first LV AC output into a first HV DC output, wherein the first HV output assembly defines a first input stage; a polarity selector coupled between the second output junction of the first drive assembly and the first and second input stages of the first HV output assembly, the polarity selector operable between a first configuration and a second configuration; wherein in the first configuration the first HV DC output has a positive polarity; and wherein in the second configuration the first HV DC output has a negative polarity.

A polarity-selectable high voltage direct current power supply including a first drive assembly that transforms a first low voltage DC input into a first medium voltage alternating current output; a first HV output assembly that transforms the first LV AC output into a first HV DC output, wherein the first HV output assembly defines a first input stage; a polarity selector coupled between the second output junction of the first drive assembly and the first and second input stages of the first HV output assembly, the polarity selector operable between a first configuration and a second configuration; wherein in the first configuration the first HV DC output has a positive polarity; and wherein in the second configuration the first HV DC output has a negative polarity.

A Neutralizer for an ion thruster of a spacecraft comprises a cathode for emission of electrons, a support with an opening inside which the cathode is supported in a radially spaced manner, and an electrically conductive shielding which surrounds said opening and is electrically insulated from the support, wherein a ring is mounted between the shielding and the cathode and is electrically insulated from the shielding and radially spaced from the cathode.

A method for controlling an ion thruster including an emission electrode, an extraction electrode and a conductive liquid which is deposited on the emission electrode, the ion thruster configured for emitting an ion beam when an electric field is applied to the conductive liquid, the ion beam providing thrust to the thruster, the thrust depending on an emission current I.sub.em and an ion emission speed, the method including the following steps: adjusting the emission current to a setpoint value I.sub.c by applying a threshold emission potential V.sub.thresh to the emission electrode by means of a current generator; and when the setpoint value I.sub.c of the emission current is reached, adjusting the emission speed by applying an extraction potential V.sub.ext to the extraction electrode by means of a voltage generator in order to bring the emission potential V.sub.em to a predetermined value V.sub.empr=V.sub.thresh+V.sub.ext.

An electrospray emitter can include an emitter structure connected to a reservoir containing a working material in electrical communication with a first electrode and an electrode separated from an apex of the emitter structure by a distance, wherein a surface of the grid electrode proximal the emitter structure comprises at least one coating.

An integrated ion thruster unit for a spacecraft can include a unit housing including a thrust face, and a plurality of tiles arranged in an array on the thrust face. Each of the tiles can include an emitter and an extractor configured to provide a reference voltage with respect to the emitter. The emitter can include a plurality of tips configured to emit ions in a thrust direction from an ionic liquid propellant in response to an applied voltage.