Abstract: Polymeric electro spray emitters and related methods are generally described. In some embodiments, an emitter may be made from an ionic electro active polymer. The composition of the electro spray emitters described herein may enable the transport of ions and/or liquid ion sources, such as an ionic liquid or room temperature molten salt, through the bulk of the polymeric emitter. In some embodiments, the described emitters may be fabricated using a mixture of an ionic electroactive polymer, a solvent, and a liquid ion source to at least partially mitigate swelling effects of the polymer emitter that may otherwise occur when the one or more emitters are exposed to the liquid ion source during operation.

Abstract: Bi-modal propulsion systems and related methods are generally described. In some embodiments, a bi-modal propulsion system may employ a single propellant for both chemical thruster(s), operating at elevated pressures, and electrical thruster(s) (e.g., electro spray thruster), operating at reduced pressures. The propellant pressure may be reduced to a desired operational range of the electrical thruster(s) using any appropriate construction including, for example, capillaries configured to reduce the pressure of the propellant to an operational range of the electrical thruster(s). In some embodiments, the reduced pressure of the propellant may be lower than a vapor pressure of at least one volatile component of the propellant, leading to the formation of “bubbles” within the propellant line. The presence of alternating gas and liquid phases along a flow path between a propellant tank and the electrical thruster(s) may help to electrically insulate the electrical thruster from the rest of the system.

Abstract: 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.

Abstract: Electrospray devices and methods of fabricating electrospray devices are described.

Abstract: 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.

Abstract: 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.

Abstract: Electrospray devices and methods of fabricating electrospray devices are described

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 is related to propulsion systems (e.g., electrospray devices such as electrospray emitters and/or electrospray thrusters) having a sublimable barrier that may act as a passive valve for a propellant (e.g., a source of ions). The sublimable barrier may be located and arranged such that it physically separates a propellant, such as a source of ions, from an ambient environment exterior to the propulsion system. After the sublimable barrier has sublimated due to exposure to vacuum, and where appropriate diffused out of the propulsion system, the propulsion system may be operated normally. In some embodiments, the sublimable barrier may be a solid sublimable organic compound.

Abstract: 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.

Abstract: An ionic liquid ion source can include a microfabricated body including a base and a tip. The body can be formed of a porous material compatible with at least one of an ionic liquid or room-temperature molten salt. The body can have a pore size gradient that decreases from the base of the body to the tip of the body, such that the at least one of an ionic liquid or room-temperature molten salt is capable of being transported through capillarity from the base to the tip.

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: An ionic liquid ion source can include a microfabricated body including a base and a tip. The body can be formed of a porous material compatible with at least one of an ionic liquid or room-temperature molten salt. The body can have a pore size gradient that decreases from the base of the body to the tip of the body, such that the at least one of an ionic liquid or room-temperature molten salt is capable of being transported through capillarity from the base to the tip.

Abstract: An ionic liquid ion source can include a microfabricated body including a base and a tip. The body can be formed of a porous material compatible with at least one of an ionic liquid or room-temperature molten salt. The body can have a pore size gradient that decreases from the base of the body to the tip of the body, such that the at least one of an ionic liquid or room-temperature molten salt is capable of being transported through capillarity from the base to the tip.

Abstract: The present disclosure is related to propulsion systems (e.g., electrospray devices such as electrospray emitters and/or electrospray thrusters) having a sublimable barrier that may act as a passive valve for a propellant (e.g., a source of ions). The sublimable barrier may be located and arranged such that it physically separates a propellant, such as a source of ions, from an ambient environment exterior to the propulsion system. After the sublimable barrier has sublimated due to exposure to vacuum, and where appropriate diffused out of the propulsion system, the propulsion system may be operated normally. In some embodiments, the sublimable barrier may be a solid sublimable organic compound.

Abstract: Methods and apparatus of adding propellant to a thruster assembly are described. A first end of a beaker is disposed in an opening of the tank, where the beaker contains propellant and the first end of the beaker includes a breakaway bottom. The thruster assembly and beaker are placed in a first environment, where the first environment is substantially a vacuum and/or an environment composed substantially of gases that can be absorbed by the propellant. A plunger in the beaker is depressed to cause the breakaway bottom of the beaker to break and the propellant to flow into the tank of the thruster assembly. The thruster assembly is removed from the first environment and the beaker is removed from the opening. A cap is added to complete the assembly. The assembly contains a vent to allow gases to escape the interior of the tank.

Abstract: An ionic liquid ion source can include a microfabricated body including a base and a tip. The body can be formed of a porous material compatible with at least one of an ionic liquid or room-temperature molten salt. The body can have a pore size gradient that decreases from the base of the body to the tip of the body, such that the at least one of an ionic liquid or room-temperature molten salt is capable of being transported through capillarity from the base to the tip.

Abstract: Methods and apparatus of adding propellant to a thruster assembly are described. A first end of a beaker is disposed in an opening of the tank, where the beaker contains propellant and the first end of the beaker includes a breakaway bottom. The thruster assembly and beaker are placed in a first environment, where the first environment is substantially a vacuum and/or an environment composed substantially of gases that can be absorbed by the propellant. A plunger in the beaker is depressed to cause the breakaway bottom of the beaker to break and the propellant to flow into the tank of the thruster assembly. The thruster assembly is removed from the first environment and the beaker is removed from the opening. A cap is added to complete the assembly. The assembly contains a vent to allow gases to escape the interior of the tank.

Abstract: An ionic liquid ion source can include a microfabricated body including a base and a tip. The body can be formed of a porous material compatible with at least one of an ionic liquid or room-temperature molten salt. The body can have a pore size gradient that decreases from the base of the body to the tip of the body, such that the at least one of an ionic liquid or room-temperature molten salt is capable of being transported through capillarity from the base to the tip.

Abstract: Electrically conductive aerogel and methods of making the same are disclosed. A solution is provided. The solution is cured to form a polymer. The polymer is carbonized to form the conductive aerogel.