Abstract: Systems and methods for nuclear reactor direct drive of a cryocooler turbine. A nuclear thermal propulsion (NTP) system may have a nuclear reactor that heats a thermal working fluid for directly driving the turbine to power a cryogenic fluid management (CFM) system for keeping propellant at cryogenic temperatures. The features may be used on NTP rockets. The propellant may be liquid hydrogen.

Abstract: A gimbal assembly for a flexible conduit configured to convey a medium is disclosed herein. The gimbal assembly includes a first component including a first plurality of struts that terminate in a first socket defining a first cavity of a first geometric configuration. The gimbal assembly also includes a second component including a second plurality of struts that terminate in a second socket defining a second cavity of a second geometric configuration. A joint fastener is configured to couple the first socket to the second socket. The joint fastener includes a first portion that geometrically corresponds to the first cavity and a second portion that geometrically corresponds to the second cavity. The first portion is configured to be immovably seated within the first cavity, and the second portion is configured to be movably retained by the second socket such that the first component can rotate relative to the second component.

Abstract: A representative spacecraft system includes a launch vehicle elongated along a launch vehicle axis and having at least one stage carrying a corresponding rocket engine. The representative system further includes an annular support structure carried by the at least one stage and positioned to support a cargo spacecraft having a service module and a cargo module. The cargo module of the cargo spacecraft is positioned along the launch vehicle axis in a direction distal from the support structure, and at least a portion of the service module of the cargo spacecraft positioned within an annulus of the support structure.

Abstract: Systems and methods for equalizing fluid levels within a vent line and a propellant tank in which the vent line is located are discussed herein. The vent line includes a vent valve and an equalization valve. The vent valve can be included in a vent duct of the vent line. The equalization valve is included in a bottom wall (i.e., a low point) of the vent duct of the vent line. A controller is also included in the system to instruct a vent valve and the equalization valve to open and close.

Abstract: A representative fault-tolerant rotating electromechanical actuator comprises a permanent magnet synchronous motor with first and second windings that each comprise three phases. First and second voltage source inverters (VSI) provide output signals independently with respect to each other. The first VSI provides output signals to drive the three phases of the first winding, and the second VSI provides output signals to drive the three phases of the second winding. The three phases of the first winding are driven simultaneously with the three phases of the second winding. Control electronics monitor signals associated with the three phases of the windings and detect a fault condition within a first phase of the first winding. The control electronics command the first VSI to drive only second and third phases of the first winding while simultaneously commanding the second VSI to drive the three phases of the second winding.

Abstract: Systems and methods for a fully reusable upper stage for a multi-stage launch vehicle are provided. The reusable upper stage uses an aerospike engine for main propulsion and for vertical landing. A heat shield can include a plurality of scarfed nozzles embedded radially around a semi-spherical surface of the heat shield, wherein inboard surfaces of the plurality of scarfed nozzles collectively define an aerospike contour. The heat shield can be actively cooled to dissipate heat encountered during reentry of the upper stage.

Abstract: Embodiments disclosed herein include fastener assemblies. In an embodiment, a fastener assembly comprises a sleeve with a hole, an inner surface, and top and bottom ends. The top end has a planar surface, and the inner surface has a cylindrical surface. The fastener assembly includes a fastener downwardly extending through the hole, and having a drive slot, a head, a shank, and a threaded region. The head is positioned within the bottom end. The head is separated from the threaded region by the shank. The fastener assembly comprises a cover disposed on the top end and having an access hole and top and bottom surfaces. The cover is welded to the sleeve to define an inner cavity between the cover, sleeve, and fastener head. The access hole is positioned over the drive slot. The cover, sleeve, and fastener comprises materials having high temperature, strength and oxidation resistances.

Abstract: Systems and methods for controlling additive manufacturing processes are disclosed. The systems can include multiple laser directors, soot-removal devices, magnetic chucks, replenishable powder distribution blades, automated powder level detectors, and/or overall process automation techniques.

Abstract: Stud-propelling mechanisms for securing a launch vehicle to a landing platform, and associated systems and methods, are disclosed. A representative system includes a fastening mechanism carried by a landing support element of a portion of a launch vehicle, the mechanism configured to fasten the landing support element to the landing surface when the launch vehicle portion is on the landing surface. The fastening mechanism can include a barrel structure for propelling a stud and an interference portion positioned to receive the stud upon activation of an energetic material that propels the stud. The stud can bind in the interference portion and in the landing surface to fasten the landing support element to the landing surface. A representative method includes automatically fastening a portion of a launch vehicle to a landing surface using a stud carried by the portion of the launch vehicle.

Abstract: Quick disconnect devices for high pressure fluid transfer, and associated systems and methods are disclosed. A representative quick disconnect system includes a first connector and a second connector. The second connector can have an opening sized and shaped to receive a first end of the first connector. The second connector can include a poppet positioned to open the first connector when the first connector is connected to the second connector. The second connector can include an inner sleeve moveable between a first position wherein the poppet head forms a fluid-tight seal with the annular seat of the inner sleeve, and a second position wherein the second end portion is open to permit fluid flow through the end portion of the inner sleeve. In some embodiments, the inner sleeve is pressure balanced in every direction.

Abstract: A gimbal assembly for a flexible conduit configured to convey a medium. The gimbal assembly includes a first component including a first plurality of struts that terminate in a first socket defining a first cavity of a first geometric configuration. The gimbal assembly also includes a second component including a second plurality of struts that terminate in a second socket defining a second cavity of a second geometric configuration. A joint fastener is configured to couple the first socket to the second socket. The joint fastener includes a first portion that geometrically corresponds to the first cavity and a second portion that geometrically corresponds to the second cavity. The first portion is configured to be immovably seated within the first cavity, and the second portion is configured to be movably retained by the second socket such that the first component can rotate relative to the second component.

Abstract: Systems and methods for bonding objects using energetic welding are disclosed. A representative system includes a launch vehicle portion, one or more landing support elements positioned to support the launch vehicle portion when the launch vehicle portion lands on a landing surface, and a bonding device carried by at least one of the landing support elements and configured to form a bond between the bonding device and the landing surface when the launch vehicle portion is on the landing surface. The bond may include a weld. A further representative system includes a bonding device with an energetic material and an anchor element, wherein activating the energetic material deforms the anchor element onto a landing surface to form a weld between the bonding device and the landing surface. A representative method includes automatically bonding a portion of a launch vehicle to a landing surface in response to landing.

Abstract: A modular damper plug forming a multi-volume acoustic resonator in an acoustic liner of a rocket engine is provided. In one aspect, the damper plug includes a main body including a top surface spaced from a bottom surface by a first height, a left surface spaced from a right surface by a width, and an exterior surface spaced from an interior surface by a length. A chamber within the main body extends along a part of the height, a part of the width, and a part of the length, and communicates with the top surface through an opening. The chamber also communicates with the interior surface through one or more ducts. The main body is sized and shaped to be received in any one of a plurality of cavities in the acoustic liner. The chamber includes an upstream volume of the acoustic resonator, and the one or more ducts communicate with a downstream volume of the acoustic resonator when the damper plug is received in any one of the plurality of cavities.

Abstract: A high pressure engine propulsion system, such as a rocket engine, having improved engine performance is described herein. A liquid propellant, such as liquid oxygen, is paramagnetic. Cavitation bubbles of the liquid propellant can form in an inducer tunnel of a turbopump when the pressure in the turbopump inlet drops below the vapor pressure of the liquid propellant. The turbopump includes a magnetic field source external to the inducer tunnel to generate or provide a steady magnetic field across or through the inducer tunnel. The steady magnetic field interacts with the paramagnetic propellant, thereby reducing or eliminating cavitation bubble growth, causing cavitation bubbles to collapse, retaining cavitation bubbles within the inducer tunnel, the like, or combinations thereof.

Abstract: Composite materials and methods of manufacturing composite materials, such as for use in aerospace parts, are described herein. A representative method for manufacturing a coated composite material structure includes applying a plurality of material layers to a preform structure. The plurality of material layers can include at least one first material layer (including a first matrix precursor), and at least one second material layer (including a second matrix precursor and a coating precursor). The method can also include infusing the preform structure with the first and second matrix precursors and the coating precursor from the plurality of material layers. The method can further include heating the infused preform structure to concurrently form a composite material structure and a coating on at least a portion of the composite material structure.

Abstract: Systems and methods for laser beam welding in a vacuum and for controlling laser beam welding processes, such as for use in manufacturing aerospace parts, are described herein. In some embodiments, a laser beam welding system can include an optical head movably positioned within a vacuum chamber. The optical head can be configured to direct a laser beam toward a part positioned within the vacuum chamber to melt and fuse the part.

Abstract: A rocket engine propulsion system having improved engine performance is described herein. The rocket engine propulsion system includes multiple axial counterbalances to reduce or eliminate axial thrust exerted on components of a turbopump. The axial counterbalances can allow for a larger range of axial thrust forces while coupling this ability to a rotational speed (e.g., rotations per minute, or RPM) of a shaft. The axial counterbalances include protrusions that extend circumferentially around a shaft that mate with protrusions on swing arms. The swing arms are rotatably attached to a bracket which is constrained by a static support.

Abstract: A representative phase-shift based method for using a transformer system to detect movement of an object, and associated systems and methods are disclosed. A representative transformer system detects movement of an object and includes an excitation coil configured to receive an excitation coil input signal that results from an input sinusoidal signal. The transformer further includes first and second sensing coils, and a core configured to be operatively coupled to the object. The core moves relative to the first and second sensing coils when the object moves. First and second impedance loads are connected to the first and second sensing coils, respectively. The two impedance loads have different phase-shifting characteristics. A phase-shift sensing circuit determines a phase-shift between the excitation coil input signal and the input sinusoidal signal that is correlated with a position of the core relative to the first and second sensing coils.

Abstract: A rocket engine propulsion system having improved engine performance is described herein. The rocket engine propulsion system includes an axial counterbalance to reduce or eliminate axial thrust exerted on components of a turbopump. The axial counterbalance can allow for a larger range of axial thrust forces while coupling this ability to a rotational speed (e.g., rotations per minute, or RPM) of a shaft. The axial counterbalance includes a protrusion on that extends circumferentially around a shaft that mates with a protrusion on a swing arm. The swing arm is rotatably attached to a bracket which is constrained by a static support.

Abstract: A representative system includes an alignment tool for aligning attachment interfaces of horizontally-oriented launch vehicle portions. The tool can include a receiver assembly for connecting to a first launch vehicle portion and an actuation assembly for connecting to a second launch vehicle portion. When a first connecting element of the receiver assembly is engaged with a second connecting element of the actuation assembly, the second connecting element can apply force to the receiver assembly, and the actuator assembly applies an opposite force to the second launch vehicle portion, to align fastening features in the launch vehicle portions and/or to reshape the launch vehicle portions. A representative method includes connecting the alignment tool to the launch vehicle portions and operating the tool to apply oppositely-directed forces to align the launch vehicle portions for installing fasteners to connect the launch vehicle portions. One or more bracing beams can connect two tools together.