Abstract: A coupling includes first and second housings, a valve element, and a guide link. The first housing is rotatable relative to the second housing. The first housing has helical cam slots and the second housing has linear cam tracks. The guide link is in the first housing and is fixed with the valve element. The guide link carries cam rollers. The cam rollers ride in the helical slots and the linear cam tracks. Rotation of the first housing causes rotation of the helical slots. The rotation of the helical slots induces the cam rollers to travel along the helical slots and along the linear cam tracks such that the guide link translates linearly. The valve element moves with the guide link between open and closed positions.

Abstract: A monopropellant thruster according to an exemplary aspect of the present disclosure includes, among other things, a first part having a catalyst bed, a thrust chamber, and a nozzle. The first part is integrally formed via a single additive manufacturing process. The thruster further includes a second part, which is a closeout. A method is also disclosed.

Abstract: A spacecraft propulsion system including a first thruster system including a first power processing unit connected to a first thruster string via a crossover switching unit and connected to a second thruster string via the crossover switching unit. A second thruster system including a second power processing unit connected to the second thruster string via the crossover switching unit and to the first thruster string via the crossover switching unit. A controller is connected to each of the first power processing unit, the second power processing unit, and the crossover switching unit.

Abstract: A shoot-through protection circuit including a first switch connected to a positive bus and connected to a first center node via a first electrical path, a second switch connected to a negative bus and connected to the first center node via a second electrical path, a circuitous third electrical path connecting the first center node to a first load output, a first magnetic core surrounding the first electrical path and the circuitous third electrical path, a second magnetic core surrounding the second electrical path and the circuitous third electrical path, and wherein a polarity of one of the first electrical path and the second electrical path is aligned with a polarity of the circuitous third electrical path within the corresponding one of the first magnetic core and the second magnetic core and a polarity of the other of the first electrical path and the second electrical path opposes the polarity of the circuitous third electrical path within the corresponding one of the first magnetic core and the seco

Abstract: A reconfigurable power processing unit for a spacecraft including a plurality of power modules. Each of the power modules includes a first power source and a second power source. The first power source and the second power source are configured to be in series in a first state and in parallel in a second state. A plurality of contactors connect each power module to at least one of another power module in the plurality of power modules and a power processing output and are configured to control the state of the power modules.

Abstract: A fuel-isolation system includes a valve body that defines a flow passage that extends from an inlet to an outlet, a rupture diaphragm in the flow passage and fluidly sealing the inlet from the outlet, and an actuator situated adjacent the rupture diaphragm. The rupture diaphragm is integral with the valve body. The actuator includes a plunger that is configured to move and cause breach of the rupture diaphragm and thereby fluidly connect the inlet and the inlet.

Abstract: A solid rocket propellant includes a hydroxyl-terminated polybudadiene (HTPB) binder system having a high molecular weight diol that is greater than thirty carbon atoms (>C30) and less than fifty carbon atoms (<C50) and excluding dimeryl diisocyanate (DDI).

Abstract: A valve device (20) includes male and female housings (22, 24) that together define a fluid through-passage (28). The male and female housings have, respectively, exterior and interior annular channels (22a, 24a). The male housing is receivable into the female housing such that the exterior and interior annular channels together define a toroidal tube. First and second valve elements (30, 32) are disposed, respectively, in the male and female housings. Ball locks (36) are receivable into the toroidal tube and axially lock the male and female housings together. A lock (40) engageable when the first and second valve elements are in functional alignment and which when engaged rotationally locks the male and female housings.

Abstract: A circuit for igniting and sustaining an electron discharge includes an ignitor circuit. The igniter circuit includes a high voltage transformer and a switch connected in series between a primary of the transformer and a DC source return. The switch is configured to receive a driving signal. A reset circuit is connected in parallel to the primary of the high voltage transformer. A first rectifier is connected in series between a secondary of the high voltage transformer and a keeper. A terminal of the secondary of transformer is connected to a cathode. The circuit for igniting and sustaining the electron discharge also includes a sustaining circuit having a current source with a return connected to a cathode and a second rectifier connected in series between the current source and the keeper.

Abstract: A liquid fuel rocket engine according to one example includes a combustor, a liquid fuel repository connected to the combustor via a fuel line and a first valve, an oxidizer repository connected to the combustor via an oxidizer line and a second valve, a valve controller configured to output a valve control current to the first valve, the valve controller storing instructions for determining at least one actual minimum impulse bit of a valve based on a current profile and a voltage profile of a single operation of the first valve, and to adjust valve controls to account for the at least one actual minimum impulse bit.

Abstract: An article includes a completed fabric structure that has multiple plies of fiber reinforced fabric. A first portion of the fabric structure has a three-directional fiber reinforced configuration and, exclusive of the first portion, a second portion of the fabric structure having a two-directional fiber reinforced configuration. In the three-directional fiber reinforced configuration there are multiple plies that are bound together via a matrix and a plurality of fibers normal through the multiple plies. In the two-directional fiber reinforced configuration the multiple plies are bound to one another via the matrix and not fibers normal through the multiple plies.

Abstract: A shoot-through protection circuit includes a current sensor providing a sensor signal connected to a comparator input via at least a burden resistor. A switch protection circuit including a protection input connected to an output of the comparator and a plurality of outputs. Each of the outputs is connected to a corresponding switch in a plurality of stacked switches. Wherein the switch protection circuit is configured to drive each switch of the plurality of stacked switches open in response to a positive output signal from the comparator.

Abstract: An injector for a liquid rocket engine includes an array of injector elements. Each injector element includes a central passage and a plurality of peripheral transverse passages. The central passages are configured to provide axial injection flow and the peripheral transverse passages are configured to provide swirl injection flow about the axial injection flow. A portion of the injector elements are configured to provide the swirl injection flow in a clockwise direction and another portion of the injector elements are configured to provide the swirl injection flow in a counter-clockwise direction. The injector elements are arranged to form a plurality of circumferential rows. The injector elements of each individual circumferential row are either all of the clockwise direction or all of the counter-clockwise direction. At least one of the circumferential rows is of the clockwise direction and at least one of the circumferential rows is of the counter-clockwise direction.

Abstract: An injector element for a liquid propellant rocket engine includes an oxidizer conduit, a central cavity that is fluidly coupled with the oxidizer conduit downstream of the oxidizer conduit, a first annulus that at least partially surrounds the oxidizer conduit and is fluidly coupled with an ignition fluid supply downstream of the ignition fluid supply, and a second annulus that at least partially surrounds the oxidizer conduit and is fluidly coupled with a fuel supply downstream of the fuel supply. The second annulus is fluidly coupled between the first annulus and the central cavity.

Abstract: A Hall thruster includes an annular discharge region and an annular cathode concentric to the annular discharge region.

Abstract: A liquid propellant rocket engine includes a pump that is disposed along a central axis. The pump includes a purge system, a collection annulus in fluid communication with the purge system, and a drain. The collection annulus has an outer diameter wall, an inner diameter wall, and an end wall. The end wall defines an annular channel that has a channel depth that varies circumferentially. The drain opens to the collection annulus. At the drain, the annular channel has a lowest point at which the channel depth is maximum depth.

Abstract: A solid rocket propellant includes a binder that has hydroxyl-terminated polybudadiene (HTPB) with a curative that is selected from isocyanate-terminated polyether, isocyanate-terminated polysiloxane, or combinations thereof.

Abstract: A turbopump includes an impeller (22) that is rotatable about an axis (A). A discharge collector (28) is located radially outward of the impeller. A passage (30) fluidly connects the impeller to the discharge collector. The passage is curved.

Abstract: A catalytic thruster includes a reaction chamber that extends between first and second opposed chamber ends. The first chamber end includes a thermal standoff cup. There is a catalyst bed in the reaction chamber, and a feed tube extends into the reaction chamber through the thermal standoff cup.

Abstract: A pump includes an axial inducer. The axial inducer includes a housing that has an internal surface that defines an axial fluid passage. A rotor is disposed about a central axis in the fluid passage. The rotor includes at least one blade that defines at least one blade tip. The internal surface of the housing defines a plurality of grooves adjacent the at least one blade tip. The grooves are elongated in a circumferential direction.