Abstract: A circuit (400, 700, 800) comprising: a first power source (402) supplying first current to a load (470) during a first Period of Time (“PoT”); a second power source (416) supplying a second current to the load during a second POT; a Unidirectional Current Valve (“UCV”) in series with the first power source; a current detector (420, 702, 802) in series with the UCV (422); and a switch (424) in parallel with a series combination of the current detector and UCV to bypass the UCV during the second PoT. The current detector determines whether the second period of time has commenced and whether the switch has closed.

Abstract: A duct includes first and second bellows sections. First and second torsional rings are attached to, respectively, the first and second bellows sections. First and second dynamic seals are sandwiched between the first and second torsional rings.

Abstract: A flow control system (22) includes a fuel passage network (34) that has first (36) and second (38) network portions that are in a parallel flow arrangement with each other. A fueldraulic device (40) is located in the first network portion. Operation of the fueldraulic device varies flow through the first network portion. A flow restriction orifice (42) is located in the fuel passage network and is arranged in series with, and upstream of, the fueldraulic device. The flow restriction orifice is operable to generate a pressure differential that varies responsive to the flow through the first network portion. A flow control valve (44) is located in the second network portion. The flow control valve is operable responsive to the pressure differential across the flow restriction orifice to control flow through the second network portion.

Abstract: A method for solar array (28a, 28b) deployment includes deploying a first portion of solar cells of a solar array responsive to a first drag condition, charging a battery (26) with the first portion of solar cells, activating an electric thruster (24) at a first power level using the first portion of solar cells, deploying a second portion of solar cells of the solar array responsive to a second drag condition that is lower than the first drag condition, and activating the electric thruster at a second power level that is higher than the first power level using the first portion of solar cells and the second portion of solar cells.

Abstract: A solid rocket motor includes a first solid propellant and a second solid propellant at least partially surrounding the first solid propellant. The second solid propellant is resistant to fragment impact and the first solid propellant has a higher impulse than the second solid propellant.

Abstract: A rocket motor includes a case and first and second nozzles in the case. The first nozzle is disposed in the second nozzle. The first nozzle includes a forward leg, a rear leg, and an intermediate leg. The intermediate leg has a convex conical geometry, and the forward leg has a forward lip that is spaced from the case. The rear leg has a rear lip that is spaced from the case. The forward leg and the rear leg at least partially define a flow passage through the first nozzle. The first nozzle is exclusively secured by the intermediate leg to at least one of the case or the second nozzle. At least a portion of a fragmentation system is disposed between the first and second nozzles.

Abstract: A modified projectile includes a projectile, a container, and a liquid propellant in the container. The container is detachably attached to the projectile.

Abstract: A thruster nozzle (24) includes a throat (28) and a nozzle end portion (30) that is integral with the throat. The nozzle end portion includes an outer wall (32) that has a plurality of circumferentially-disposed nozzle features or connectors (34). A brace (26) may be disposed at least partially around the thruster nozzle and mated with the nozzle features to restrict relative movement between the thruster nozzle and the brace. The brace may be attached with a vehicle body (22) of a vehicle.

Abstract: An ignition system includes a multi-metallic ignition body that has at least two metallic elements in contact with each other. The metallic elements define an ignition initiation temperature above which there is a self-sustaining alloying reaction. A fluorine-containing body is in contact with the multi-metallic ignition body. The metallic elements may include palladium or palladium-ruthenium and aluminum.

Abstract: A valve assembly includes a valve body, a first spring seat disposed within the valve body, a preload spring disposed within the valve body and mated with the first spring seat, and a second spring seat disposed within the valve body and mated with the preload spring. The second spring seat is adjustably mated to the valve body.

Abstract: A fragmenting nozzle system includes a first nozzle at least partially disposed within a second nozzle. The first nozzle includes an ablative shell, a syntactic foam support disposed between the ablative shell and the second nozzle, and an ignition system disposed at least partially within the syntactic foam support. For example, the ignition system is operable to generate a controlled-energy deflagration pressure wave that fragments the first nozzle but not the second nozzle.

Abstract: An end-burning grain of a solid rocket motor or other gas-generating device is supplemented with one or more sticks of high-burn-rate propellant embedded in a matrix of a relatively low-burn-rate propellant. The sticks increase the burning surface area as the grain burns by forming conical indentations in the surface.

Abstract: A turbopump machine includes a housing, a shaft rotatably supported in the housing on a set of bearings, an axial pump coupled with the shaft, a circumferential discharge volute fluidly coupled with the axial pump, and a turbine coupled with the shaft. The turbine includes a blade row disposed in an axial turbine flowpath that has an axial turbine flowpath discharge that is fluidly coupled with the circumferential discharge volute. A cooling passage is disposed between the housing and the shaft about the set of bearings. The cooling passage has a cooling passage discharge that is fluidly coupled with the circumferential discharge volute. The cooling passage discharge is adjacent the axial turbine flowpath discharge. A seal isolates the cooling passage discharge from the axial turbine flowpath discharge.

Abstract: A rocket motor (20) includes a nozzle (22) and a solid propellant section (24) in communication with the nozzle. The solid propellant section includes a first energetic grain layer (38, 32) that has a top surface and a bottom surface, and a second energetic grain layer (40, 44) that has a top surface and a bottom surface. The second layer is located on top of the first layer. The bottom surface of the second energetic grain layer partially abuts the top surface of the first energetic grain layer, and the bottom surface of the second energetic grain layer and the top surface of the first energetic grain layer define a region (46, 48) therebetween. A powder energetic (49) is disposed in the region.

Abstract: A valve assembly includes a housing (22) that has a fluid input (24) and a fluid output (26). A pintle (30) is disposed in the housing, and an actuator (36) is operatively coupled to move the pintle. The pintle includes a passage (32) that fluidly couples the fluid output with a pressure balance volume (34) located between the pintle and the housing adjacent the linear actuator. A controller (38) is electrically connected with the actuator, and there is a variable flow area (40) from the fluid input to the fluid output that is defined between the pintle and the housing.

Abstract: A propulsion system according to an exemplary aspect of the present disclosure includes, among other things, a pressurant selectively released from a pressure tank to drive a pump to sustain propellant flow for main combustion.

Abstract: A propellant includes a binder system that has a polybutadiene component, a polytetrahydrofuran component, and an anti-oxidant component. In an example, the propellant includes a solid oxidizer, a solid fuel, and a binder system that holds the solid oxidizer and the solid fuel together. The binder system includes a polybutadiene component, a hydrocarbon diluent component of a higher level of saturation than the polybutadiene component, and an anti-oxidant component.

Abstract: A method includes forming at least one fragment wrap of a fragmentation structure by providing at least one flexible fragment strand that includes a plurality of discrete fragments held together in a pattern by a flexible media, and applying the at least one flexible fragment strand around a core piece to form the at least one fragment wrap.

Abstract: A munition includes a composite case, a blast cone housed by the composite case, a grenade aft of the blast cone and housed by the composite case, a first attenuator forward of the blast cone, and a second attenuator aft of the blast cone and forward of the grenade.

Abstract: A monopropellant includes 30-70% by weight of an oxidizer including hydroxylammonium nitrate, 5-50% by weight of a fuel, and a burn rate modifier in a non-zero amount of up to 3% by weight. The burn rate modifier can be selected from vanadium salts, iron salts, and combinations thereof. The monopropellant is a stable liquid between ?20 C and 100 C at ambient pressure.