Abstract: A rocket motor has an electrically operated propellant initiator for a propellant grain that includes an electrode arrangement configured to concentrate an electric field at an ignition electrode for igniting an electrically operated propellant. The rocket motor includes a combustion chamber containing at least one propellant grain and an electrically operated propellant initiator operatively coupled to the propellant grain to initiate combustion of the propellant grain. The electrically operated propellant initiator includes the electrically operated propellant and at least one pair of electrodes configured to ignite the electrically operated propellant. The pair of electrodes includes a ground plane electrode and an ignition electrode. When an electrical input is applied to the electrically operated propellant initiator, the electric field is concentrated at the ignition electrode to ignite the electrically operated propellant at the location where the ignition electrode is arranged.

Abstract: A rocket motor has an electrically operated propellant initiator for a propellant grain that includes an electrode arrangement configured to concentrate an electric field at an ignition electrode for igniting an electrically operated propellant. The rocket motor includes a combustion chamber containing at least one propellant grain and an electrically operated propellant initiator operatively coupled to the propellant grain to initiate combustion of the propellant grain. The electrically operated propellant initiator includes the electrically operated propellant and at least one pair of electrodes configured to ignite the electrically operated propellant. The pair of electrodes includes a ground plane electrode and an ignition electrode. When an electrical input is applied to the electrically operated propellant initiator, the electric field is concentrated at the ignition electrode to ignite the electrically operated propellant at the location where the ignition electrode is arranged.

Abstract: A system is used for additively manufacturing propellant elements, such as for rocket motors, includes partially curing a propellant mixture before extruding or otherwise dispensing the material, such that the extruded propellant material is deposited on the element in a partially-cured state. The curing process for the partially-cured extruded material may be completed shortly after the material is put into place, for example by the material being heated at or above its cure temperature, such that it finishes curing before it fully cools. The propellant material may be prepared by first mixing together, a fuel, an oxidizer, and a binder, such as in an acoustic mixer. After that mixing a curative may be added to the mixture. The propellant mixture may then be directed to an extruder (or other dispenser), in which the mixture is heated to or above a cure temperature prior to the deposition, and then deposited.

Abstract: A satellite has thrusters that are integral parts of its frame. The frame defines cavities therein where thrusters are located. The thrusters may include an electrically-operated propellant and electrodes to activate combustion in the electrically-operated propellant. The frame may be additively manufactured, and the propellant and/or the electrodes may also be additively manufactured, with the frame and the propellant and/or the electrodes also being manufactured in a single process. In addition the thrusters may have nozzle portions through which combustion gases exit the thrusters. The thrusters may be located at corners and/or along edges of the frame, and may be used to accomplish any of a variety of maneuvers for the satellite. The satellite may be a small satellite, such as a CubeSat satellite, for instance having a volume of about 1 liter, and a mass of no more than about 1.33 kg.

Abstract: A rocket motor has a nozzle that is reconfigurable by erosion or ablation of the material around the throat of the nozzle. The nozzle throat has layers of materials with different erosion characteristics, with the erosion occurring so as to achieve the desired nozzle characteristics (configurations) during different parts of the fuel burn. The nozzle throat includes relatively-high-erosion material layers and relatively-low-erosion material layers, with some layers of the throat resisting erosion, while other of the layers erode or ablate relatively quickly. The relatively-low-erosion material layers may act as thermal barriers to fix the throat at relatively stable geometry for long periods of time, such as during most of the burn of different fuel segments, with the relatively-high-erosion material layers allowing rapid transition of the throat from one geometry to the next. The layers may be made by resin transfer molding (RTM).

Abstract: An effector health monitor system is configured for coupling with an energetic component. The effector health monitor system includes a characteristic sensor suite including at least first and second characteristic sensors. The first characteristic sensor is proximate to the energetic component and configured to measure a failure characteristic of the energetic component. The second characteristic sensor is configured to measure at least one environmental characteristic proximate to the energetic component. A communication hub is coupled with the first and second characteristic sensors, and is configured to communicate the measured failure and environmental characteristics outside of an effector body. A failure identification module compares the measured failure characteristic with a failure threshold and identifies a failure event.

Abstract: Microwave energy is used to ignite and control the ignition of electrically operated propellant to produce high-pressure gas. The propellant includes conductive particles that act as a free source of electrons. Incoming microwave energy accumulates electric charge in an attenuation zone, which is discharged in the form of dielectric breakdowns to create local randomly oriented currents. The propellant also includes polar molecules. The polar molecules in the attenuation zone absorb microwave energy causing the molecules to rapidly vibrate thereby increasing the temperature of the propellant. The increase in temperature and the local current densities together establish an ignition condition to ignite and sustain ignition of an ignition surface of the attenuation zone as the zone regresses without igniting the remaining bulk of the propellant.

Abstract: A combustible element includes regions of fuel material interspersed with regions of oxidizer material. The element may be made by additive manufacturing processes, such as three-dimensional printing, with the fuel material regions and the oxidizer material regions placed in appropriate locations in layer of the combustible element. For example, different extruders may be used to extrude and deposit portions of a fuel filament and an oxidizer filament at different locations in each layer of the combustible element. The combustible element may define a combustion chamber within the element, where combustion occurs when the combustible element is ignited. The fuel material and the oxidizer material may be selected, and their relative amounts may be controlled, such that desired relative amounts of fuel and oxidizer are present for combustion with desired characteristics, such as combustion rate.

Abstract: A rocket motor has a nozzle that is reconfigurable by erosion or ablation of the material around the throat of the nozzle. The nozzle throat has layers of materials with different erosion characteristics, with the erosion occurring so as to achieve the desired nozzle characteristics (configurations) during different parts of the fuel burn. The nozzle throat includes relatively-high-erosion material layers and relatively-low-erosion material layers, with some layers of the throat resisting erosion, while other of the layers erode or ablate relatively quickly. The relatively-low-erosion material layers may act as thermal barriers to fix the throat at relatively stable geometry for long periods of time, such as during most of the burn of different fuel segments, with the relatively-high-erosion material layers allowing rapid transition of the throat from one geometry to the next. The layers may be made by resin transfer molding (RTM).

Abstract: Electrically operated propellant is used to supplement the thrust provided by solid rocket motor (SRM) propellant to manage thrust produced by a SRM. The gas produced by burning the electrically operated propellant may be injected upstream of the nozzle to add mass and increase chamber pressure Pc, injected at the throat of the nozzle to reduce the effect throat area At to increase chamber pressure Pc or injected downstream of the throat to provide thrust vector control or a combination thereof. Certain types of electrically operated propellants can be turned on and off provided the chamber pressure Pc does not exceed a self-sustaining threshold pressure eliminating the requirement for physical control valves.

Abstract: A satellite has thrusters that are integral parts of its frame. The frame defines cavities therein where thrusters are located. The thrusters may include an electrically-operated propellant and electrodes to activate combustion in the electrically-operated propellant. The frame may be additively manufactured, and the propellant and/or the electrodes may also be additively manufactured, with the frame and the propellant and/or the electrodes also being manufactured in a single process. In addition the thrusters may have nozzle portions through which combustion gases exit the thrusters. The thrusters may be located at corners and/or along edges of the frame, and may be used to accomplish any of a variety of maneuvers for the satellite. The satellite may be a small satellite, such as a CubeSat satellite, for instance having a volume of about 1 liter, and a mass of no more than about 1.33 kg.

Abstract: A system is used for additively manufacturing propellant elements, such as for rocket motors, includes partially curing a propellant mixture before extruding or otherwise dispensing the material, such that the extruded propellant material is deposited on the element in a partially-cured state. The curing process for the partially-cured extruded material may be completed shortly after the material is put into place, for example by the material being heated at or above its cure temperature, such that it finishes curing before it fully cools. The propellant material may be prepared by first mixing together, a fuel, an oxidizer, and a binder, such as in an acoustic mixer. After that mixing a curative may be added to the mixture. The propellant mixture may then be directed to an extruder (or other dispenser), in which the mixture is heated to or above a cure temperature prior to the deposition, and then deposited.

Abstract: A motor assembly is provided for use with projectiles, such as munitions, having relatively low length to diameter ratios. The motor assembly has an aerospike nozzle and a casing disposed about the aerospike nozzle, where interior aerospike volume contains propellant and where walls of both the cowl of the casing and of the aerospike nozzle jointly define a combustion chamber.

Abstract: A method of additively manufacturing propellant elements, such as for rocket motors, includes partially curing a propellant mixture before extruding or otherwise dispensing the material, such that the extruded propellant material is deposited on the element in a partially-cured state. The curing process for the partially-cured extruded material may be completed shortly after the material is put into place, for example by the material being heated at or above its cure temperature, such that it finishes curing before it fully cools. The propellant material may be prepared by first mixing together, a fuel, an oxidizer, and a binder, such as in an acoustic mixer. After that mixing a curative may be added to the mixture. The propellant mixture may then be directed to an extruder (or other dispenser), in which the mixture is heated to or above a cure temperature prior to the deposition, and then deposited.

Abstract: A satellite has thrusters that are integral parts of its frame. The frame defines cavities therein where thrusters are located. The thrusters may include an electrically-operated propellant and electrodes to activate combustion in the electrically-operated propellant. The frame may be additively manufactured, and the propellant and/or the electrodes may also be additively manufactured, with the frame and the propellant and/or the electrodes also being manufactured in a single process. In addition the thrusters may have nozzle portions through which combustion gases exit the thrusters. The thrusters may be located at corners and/or along edges of the frame, and may be used to accomplish any of a variety of maneuvers for the satellite. The satellite may be a small satellite, such as a CubeSat satellite, for instance having a volume of about 1 liter, and a mass of no more than about 1.33 kg.

Abstract: A combustible element includes regions of fuel material interspersed with regions of oxidizer material. The element may be made by additive manufacturing processes, such as three-dimensional printing, with the fuel material regions and the oxidizer material regions placed in appropriate locations in layer of the combustible element. For example, different extruders may be used to extrude and deposit portions of a fuel filament and an oxidizer filament at different locations in each layer of the combustible element. The combustible element may define a combustion chamber within the element, where combustion occurs when the combustible element is ignited. The fuel material and the oxidizer material may be selected, and their relative amounts may be controlled, such that desired relative amounts of fuel and oxidizer are present for combustion with desired characteristics, such as combustion rate.

Abstract: Electrical ignition of electrically operated propellant in a gas generation system provides an ignition condition at an ignition surface between a pair of electrodes that satisfies three criteria of a current density J that exhibits a decreasing gradient along an axis normal to an ignition surface, is substantially constant across the ignition surface and exceeds an ignition threshold at the ignition surface. These criteria may be satisfied by one or more of an angled electrode configuration, a segmented electrode configuration or an additive to the electrically operated propellant that modifies its conductivity. These configurations improve burn rate control and consumption of the available propellant and are scalable to greater propellant mass to support larger gas generation systems.

Abstract: A gas generation system for generating gases, such as for use as or as part of a rocket motor in propelling a projectile, includes two or more propellant charges and electrically operated propellant initiators operatively coupled to respective of the propellant charges, to initiate combustion in the propellant charges, wherein the propellant charges are operatively isolated from one another such that the propellant charges can be individually initiated and are not ignited due to gases generated from other of the propellant charges being combusted.

Abstract: A combustible element includes regions of fuel material interspersed with regions of oxidizer material. The element may be made by additive manufacturing processes, such as three-dimensional printing, with the fuel material regions and the oxidizer material regions placed in appropriate locations in layer of the combustible element. For example, different extruders may be used to extrude and deposit portions of a fuel filament and an oxidizer filament at different locations in each layer of the combustible element. The combustible element may define a combustion chamber within the element, where combustion occurs when the combustible element is ignited. The fuel material and the oxidizer material may be selected, and their relative amounts may be controlled, such that desired relative amounts of fuel and oxidizer are present for combustion with desired characteristics, such as combustion rate.

Abstract: Electrically operated propellant thrust assist supplements an airplane's takeoff, landing or inflight maneuvers. Unlike conventional SRM propellants, the burn rate of the electrically operated propellant can be varied via an electrical input and even extinguished by interrupting the electrical to control a secondary thrust profile (e.g., amplitude, transition rates) to fulfill the needs of a given takeoff, inflight or landing maneuver and provide a smooth transition in and out of the maneuver. Multiple pairs of fixed thrusters (opposite sides of the fuselage), a single pair of gimbaled thrusters or a hybrid of fixed and gimbaled thrusters may be configured to provide all such maneuvers. Flight control inputs are passed back and forth through an interface to enable the thrust assist.