Abstract: A method of coupling a first structure to a second structure includes providing a first bushing within an opening in an upper surface of the first structure, without the first bushing extending into a second opening in the second structure. The method further includes providing an inner opening of the first bushing which defines an inner diameter, and providing a fastener at least partially within the first bushing and at least partially within the second opening. An outer surface of the fastener defines an outer diameter. The first bushing and the fastener are configured such that a space between the outer surface of the fastener and the inner opening of the first bushing defines a gap dimensioned to increase in a direction away from the upper surface of the first structure.

Abstract: Collective control using vertical velocity is provided. A system can include a data processing system comprising one or more processors, coupled with memory. The data processing system can receive, from a sensor, a velocity of an aerial vehicle along a vertical axis of a body of the aerial vehicle. The data processing system can generate a command for collective control of a pitch of blades of a rotor of the aerial vehicle based on a comparison of the velocity with a reference. The data processing system can control, via an actuator, the pitch of the blades of the rotor in accordance with the command.

Abstract: In an embodiment, a method includes producing a mixed feedstock of at least three halogenated monomer feedstocks. A first of the at least three halogenated monomer feedstocks includes an SP3 carbon, a second of the at least three halogenated monomer feedstocks includes an SP2 carbon, and a third of the at least three halogenated monomer feedstocks includes at least two SP1 carbons. The method further includes producing a polyorbital-hybrid pre-ceramic polymer comprising the SP1 carbons, the SP2 carbon, and the SP3 carbon. The polyorbital-hybrid pre-ceramic polymer is produced by reducing the mixed feedstock such that one or more halogen atoms are removed from the mixed feedstock. The method also includes fabricating the polyorbital-hybrid pre-ceramic polymer into a greenware form and producing a polyorbital-hybrid ceramic carbon comprising the SP1 carbons, the SP2 carbon, and the SP3 carbon. The polyorbital-hybrid ceramic carbon is produced by thermolyzing the polyorbital pre-ceramic polymer.

Abstract: A bearing anti-creep interface having a drive shaft, a bearing race, and a hub. The drive shaft extends along a rotational axis. The bearing race has an inner surface press-fit onto the drive shaft and an axial end surface defining a bearing race interface surface. The hub has an inner surface rotationally coupled to the drive shaft and an axial end surface defining a hub interface surface. The hub interface surface is in contact with the bearing race interface surface to form an interlockingjoint. The interlocking joint is configured to transfer rotational creep force of the bearing race about the rotational axis and relative to the drive shaft into an axial pressure force applied to the hub in a direction parallel with the rotational axis.

Abstract: An artificial intelligence (AI) system includes an agent to learn a policy and provide an action; the agent can be a neural network. The AI system further includes a processor to process information associated with the action and provide a state and a reward to the agent. The state is based on a number of state variables, and the agent further updates the policy based on multiple updates of the state variables to achieve the highest reward.

Abstract: Provided herein are various enhancements for solar panels and associated solar arrays. In one example, a method of manufacturing includes forming, by an additive manufacturing process, a stackup of half-panels comprising connected pairs of the half-panels each having an integrated construction comprising a webbing structure connected to a skin layer substantially covering a face. The method also includes separating the stackup into detached pairs of the half-panels, assembling a selected detached pair of the half-panels into a full panel, and attaching photovoltaic cells to a selected face of the full panel.

Abstract: Provided herein are various enhancements for aperture antenna arrays and electronically steered arrays (ESAs). A modular subarray is provided that includes horn apertures coupled to corresponding waveguide polarizers coupled to transmit waveguide filters and receive waveguide filters that establish transmit ports and receive ports. The transmit ports and the receive ports are coupled through a waveguide adapter plate to individual isolation cavities each formed in a body of an amplifier-filter module that houses amplifier/filter elements and couple transmit radio frequency signaling and receive radio frequency signaling to coaxial connections penetrating the isolation cavities.

Abstract: In one embodiment, systems and methods include an aircraft vehicle comprising a body, a first wing coupled to the body, and a second wing coupled to the body, wherein the second wing has a length greater than the first wing, wherein each of the first wing and the second wing comprises a plurality of segments, wherein the second wing comprises a wing pylon system. The wing pylon system comprises one of the plurality of segments of the second wing, a payload, and a pylon coupling the payload to the one of the plurality of segments, the pylon being disposed underneath the one of the plurality of segments, and the payload being disposed underneath the pylon. A center of lift and a center of gravity for the aircraft vehicle are aligned and each is offset from a central axis of the body.

Abstract: Systems and methods for automatically controlling landing gear responsive to detected aerial vehicle conditions. A system can receive, from one or more sensors of the aerial vehicle, altitude information and speed information of the aerial vehicle. The system can determine to lower landing gear of the aerial vehicle based on a change in a state of the aerial vehicle, and identify a condition corresponding to a type of the aerial vehicle and the state of the aerial vehicle. The system can compare the speed information and the altitude information to the condition to determine that a condition to lower landing gear is satisfied. Responsive to determining that the condition to lower the landing gear is satisfied, the system can provide a signal to lower the landing gear.

Abstract: Load volume predication for slung loads of aerial vehicles are disclosed. A system can identify parameters of a load. The system can determine a volume occupied by a superposition of locations of the cone. The system can receive from sensors or models, characteristics of an environment associated with the aerial vehicle or the load. The system can detect an obstacle in the environment. The system can take a navigational action in response to detecting the obstacle.

Abstract: A clutch having an inner ring, an outer ring, a plurality of sprags positioned between the inner ring and the outer ring, and a spring biasing each of the plurality of sprags towards the outer ring. Each of the plurality of sprags are movable between a disengaged position spaced from the inner ring and an engaged position contacting both the inner ring and the outer ring to rotationally unitize the inner ring and the outer ring.

Abstract: In one embodiment, a method for reducing drag includes forming first periodic riblets on a smooth surface of a physical object and forming second periodic riblets on the smooth surface of the physical object. The method further includes generating a flow over the first and second periodic riblets of the physical object. Each first periodic riblet comprises a first transition region at a first end of each first periodic riblet and a second transition region at a second end of each first periodic riblet. Each second periodic riblet comprises a first transition region at a first end of each second periodic riblet and a second transition region at a second end of each second periodic riblet. Each second transition region at the second end of each first periodic riblet overlaps each first transition region at the first end of each second periodic riblet. A length of each riblet of the first and second periodic riblets runs parallel to a direction of the flow.

Abstract: An active optical compressive sensing system includes an optical source to generate light for illuminating a target and a pattern generator to generate a pattern. A pattern controller controls an operation of the pattern generator to cause generation of a desired pattern. The pattern is a spatial filtering pattern that enables data compression by generating sparse scattered data. Applying the pattern allows a logarithmic resource scaling.

Abstract: A hybrid propulsion system extracts electrical power using a combined heat engine and electrical generator. The propulsion system includes a gas generator, an electrical power generator disposed upstream of the gas generator and configured to be driven by a power turbine, an output power shaft mated to the power turbine and extending through a central axis of the gas generator and power generator unit, an engine enclosure circumferentially surrounding the power generator, and a shroud disposed between the power generator and the engine enclosure. The electrical power generator includes at least one rotating member and a stationary conductive member, wherein the at least one rotating member includes a magnetic portion, and rotation of the at least one rotating member relative to stationary conductive member generates a current transmissible by one or more coupled power output cables.

Abstract: Provided herein are various enhancements for radio frequency (RF) horn antenna systems and arrays. An example apparatus includes a horn antenna array formed in a single workpiece of material comprising horn antenna elements with integrated feed networks. Each of the integrated feed networks comprise a waveguide interface flange having a port, and a filter element having a serpentine cavity coupled to the port that is at least partially formed by a base section, where a separation interface is established between the base section and an attachable cap that forms a remainder of the serpentine cavity. Each of the integrated feed networks also comprise a polarizer element having a waveguide cavity that couples between the serpentine cavity of the filter element and an associated horn antenna element that forms a signal aperture.

Abstract: A rotor system of a rotary wing aircraft includes a rotor hub including a hub arm, a rotor blade rotatably coupled to the hub arm about a longitudinal axis of the hub arm, and a first brake assembly. The first brake assembly includes a rod coupled to the rotor blade coupling and a brake shoe coupled to the rod. The brake shoe is configured to apply a force on the hub arm. An axial position of the rod is adjustable to vary the force of the brake shoe on the hub arm.

Abstract: A rotor blade configured to be installed on a rotary wing aircraft includes a spar including an inboard portion extending from a root of the rotor blade to a first spanwise position of the rotor blade and an outboard portion meeting the inboard portion at the first spanwise position. The rotor blade further includes an upper skin and a lower skin coupled the outboard portion of the spar. The first spanwise position is defined by a most inboard point at which the upper and lower skins are coupled to the spar. The inboard portion includes a top layer, a bottom layer, and an inner cavity. The top layer has a substantially constant first thickness and the bottom layer has a substantially constant second thickness, and the distance between an outer surface of the top layer and an outer surface of the bottom layer is substantially constant.

Abstract: The present invention is directed to a redox flow battery comprising at least one electrochemical cell in fluid communication with a balancing cell, said balancing cell comprising: a first and second half-cell chamber, wherein the first half-cell chamber comprises a first electrode in contact with a first aqueous electrolyte of the redox flow battery; and wherein the second half-cell chamber comprises a second electrode comprising a catalyst for the generation of O2; and wherein the second half-cell chamber does not contain an aqueous electrolyte.

Abstract: Provided herein are various techniques and equipment for establishing secure non-classical communications between distant nodes. In one example, a method includes introducing, by at least one photon source, source photons into corresponding waveguides configured to convert the source photons into randomly timed pairs of resultant non-classical photons having corresponding polarization states. The method also includes providing first photons of each of the pairs for measurement of the corresponding polarization states and timing, and providing second photons of each of the pairs for combination into a beam for transfer to a distant node and establishment of a cryptographic key, where the second photons from one of the waveguides is presented in an orthogonal polarization before combination.

Abstract: A rotor assembly for a rotary wing aircraft includes a rotor hub including a hub arm and a central opening. The rotor assembly further includes a hydraulic actuation cylinder positioned in the central opening, a pitch change shaft assembly including a pitch change shaft positioned partially within the hydraulic actuation cylinder, a pitch beam coupled to a distal end of the pitch change shaft and configured to be coupled to a rotor blade rotatably mounted to the hub arm. The rotor assembly additionally includes at least one guide rod coupled to the rotor hub and slidably coupled to an opening in the pitch change shaft.