Electrical propulsion systems and related methods are generally described. In some embodiments, an electrical propulsion system may include an electrically-actuated valve to selectively permit flow of propellant from a reservoir tank to a thruster. The valve may physically isolate the propellant from the thruster when inactivated, exhibiting a non-wetting surface which may inhibit propellant from passing through the valve towards the thrusters. In some embodiments, a valve may be activated through application of a voltage potential to the valve relative to the propellant, which may change the wettability of the valve, permitting propellant to wet and subsequently pass through the valve. The voltage potential may be adjusted to vary the wettability of the valve, resulting in the valve effectively regulating propellant flow rate. The valve may include a conductive layer, a dielectric or insulating layer, and a non-wetting layer to enhance the non-wetting behavior of the valve.

One or more electrospray emitters form an electrospray thruster, suitable for generating thrust for maneuvering and/or moving a structure to which the thruster is attached in three-dimensional space. The thruster includes a reservoir containing a fluid, preferably an ionic liquid (IL) fluid. Each electrospray emitter includes a dielectric, with channel(s) formed through a thickness thereof, and an extraction electrode, preferably an extraction grid, on an opposite side of the dielectric from the reservoir. Upon application of a sufficient electric potential differential between the extraction electrode and the fluid, the fluid flows through the channels from the reservoir, forms a Taylor cone at an outlet of each channel, and is ejected in the direction of the extraction grid to generate a thrust by the thruster for movement and/or maneuvering of the structure to which the thruster is attached.

The present invention relates to an ion thruster for propulsion of spacecrafts, including: a reservoir for a propellant, an emitter for emitting ions of the propellant, the emitter having one or more projections of porous material and a base with a first side supporting said projections and a second side connected to the reservoir, and an extractor facing the emitter for extracting and accelerating the ions from the emitter, wherein the base is impermeable to the propellant at least on said first side and has pores or channels for providing flow of propellant from the reservoir to said projections.

The present invention relates to electrospray thrusters, processes of making electrospray thrusters, and methods of using such electrospray thrusters. Applicant's thruster incorporates a unique geometry for the emitters and extractor grid that effectively eliminates ion interception on the grid, which is the primary failure mechanism of current devices, yet maintains the electric field conditions necessary for ion emission to occur. Without grid impingement, the thrust produced by the thruster is increased and thruster operational lifetime is increased substantially. Additionally, this non-traditional geometry also allows for higher electric fields at the emitter tip for a given applied voltage, thus enabling lower operational voltage of the thruster as compared to conventional designs.

To manage propellant in a spacecraft, the method of this disclosure includes storing propellant in a tank as a mixture of liquid and gas; transferring the propellant out of the tank; converting the mixture of liquid and gas propellant into a single phase, where the single phase is either liquid or gaseous; and supplying the single phase of the propellant to a thruster.

A spacecraft structure for transporting propellant to be consumed by a thruster includes storing the propellant in the spacecraft in a solid state during at least a portion of a take-off procedure and supplying the propellant to the thruster in a liquid or vaporous state when the spacecraft is in space.

Propulsion systems, such as electrospray thrusters, may include an electrically actuated valve to permit a selective flow of propellant to a thruster. The valve may be located and arranged such that it physically separates a propellant, such as a source of ions, from a thruster of the propulsion system. In some embodiments, the application of a voltage potential to the valve may wet a plurality of through holes formed in the valve with the propellant such that the propellant flows through the valve to the thruster. After the valve has been opened, the propulsion system may be operated normally.

Electrical propulsion systems and related methods are generally described. In some embodiments, an electrical propulsion system may include an electrically-actuated valve to selectively permit flow of propellant from a reservoir tank to a thruster. The valve may physically isolate the propellant from the thruster when inactivated, exhibiting a non-wetting surface which may inhibit propellant from passing through the valve towards the thrusters. In some embodiments, a valve may be activated through application of a voltage potential to the valve relative to the propellant, which may change the wettability of the valve, permitting propellant to wet and subsequently pass through the valve. The voltage potential may be adjusted to vary the wettability of the valve, resulting in the valve effectively regulating propellant flow rate. The valve may include a conductive layer, a dielectric or insulating layer, and a non-wetting layer to enhance the non-wetting behavior of the valve.

The invention relates to a solid or liquid propellant (2) tank (1) for a thruster, the tank (1) comprising means for forming a gas (9) in the tank, the tank (1) having an opening (4) of surface area S for the extraction of a flow (20) of the propellant gas from the tank (1). According to the invention, the tank (1) comprises a propellant gas flow on-off control system comprising a grid (6) arranged opposite the opening (4) of the tank (1), a first thermal regulation system (11, 21) for heating the gas (9) in the tank and a second thermal regulation system (12, 22) for heating the grid (6), said grid (6) including holes of total surface area greater than the surface area S of the opening of the tank (1).

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.