Abstract: A system including an apparatus for determining the presence of ice on an external surface of a structure is provided. The apparatus includes a sensor that includes first and second parallel ink or paint conductive traces separated by a gap. The apparatus also includes a circuit configured to measure the impedance or change in impedance between the first and second parallel ink or paint conductive traces.

Abstract: A convertible aircraft is configured to fly in a hover mode and a forward flight mode, the aircraft including a body defining a longitudinal axis and a thruster system coupled to the body and configured to apply forces to the body to fly the aircraft. The thruster system includes a first thruster configured to create a first thrust profile having a fixed direction and a variable amount. The thruster system includes a second thruster configured to create a second thrust profile having a variable direction and a variable amount. The thruster system is configured to operate in a first mode and a second mode. In the first mode, the first thrust profile and the second thrust profile are positive, and in the second mode, the first thrust profile is minimized and the second thrust profile is positive.

Abstract: Aerial navigation is disclosed. A system can detect a difference between forces applied to a plurality of ground contact points of an aerial vehicle taxiing on a ground surface. The system can determine an adjustment to a vertical component of a thrust. The thrust can be produced by at least one of a rotor or a propeller of the aerial vehicle to reduce the difference between the forces applied to the plurality of ground contact points of the aerial vehicle. The system can generate a control output to cause the at least one of the rotor or the propeller to adjust the vertical component of the thrust to reduce the difference between the forces.

Abstract: A rotor assembly for a rotary wing aircraft includes a rotor hub, a rotor blade coupling coupled to the rotor hub, a hub extender coupled to the rotor hub, and a first bearing assembly. The first bearing assembly includes a clevis coupled to the hub extender and including two arms, each arm including a clevis opening, two cylindrical bearings, each cylindrical bearing extending through one of the clevis openings, a spherical bearing positioned between the two arms and coupled to the rotor blade coupling, and a first pin extending through the two cylindrical bearings and the spherical bearing.

Abstract: The present disclosure is directed, in certain embodiments, to a flow cell battery system. A battery management system detects that a first power module and a second power module located adjacent to the first power module are operating at different states of charge. After determining that the second power module is at the lower state of charge than the first power module, a negative-side switch associated with the second power module is adjusted to an open position, thereby preventing flow of electrical current from a negative terminal of the second power module to electrical ground.

Abstract: A control system for an aircraft, the system including a pilot input device configured to receive a pilot input, a plurality of sensors, each of the plurality of sensors positioned on a corresponding landing gear of the aircraft and configured to sense a parameter on the corresponding landing gear, and a controller in communication with the plurality of sensors, the controller configured to calculate an output command based on the pilot input and the sensed parameters of the landing gear, the output command including instructions for controlling a rotor of the aircraft.

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 coupled to the outboard portion of the spar, a lower skin coupled to the outboard portion of the spar, and a blade extender surrounding and extending inboard of the root of the rotor blade.

Abstract: Provided herein are various enhancements for establishing dynamic mesh networking across a constellation of satellites and ground stations. An example method includes obtaining a request to generate a communication network for a time interval among a constellation of satellites. The method also includes identifying one or more connectivity graphs for the constellation based on a state of the constellation during at least the time interval and applying a selected routing algorithm against the one or more connectivity graphs to generate a communication route among the constellation during the time interval. The method further includes producing a set of parameters to configure routing of the communication route among the constellation to establish the communication network for the time interval.

Abstract: Aerial navigation is disclosed. A system can receive, via a camera coupled to the aerial vehicle, image frames of a platform. The system can generate, via a first model trained with machine learning on reference patterns, a feature map that identifies a predetermined pattern. The system can input, responsive to recognition of the predetermined pattern, a feature map generated by the first model into a second model trained with machine learning on slope-intercept functions. The system can determine, based on an offset of the zone in the image frame and the orientation of the aerial vehicle relative to the zone, a vector between the aerial vehicle and the zone. The system can provide for display, via a display device communicatively coupled to the computing system, an indication of the vector overlayed on a digital representation of the image frame.

Abstract: A rotor blade configured to couple to a rotor assembly having an axis of rotation includes a blade radius R between the axis of rotation and an outboard end of the rotor blade when coupled to the rotor assembly. When an inboard end of the rotor blade is coupled to the rotor assembly at about x/R=0.10, between about 18 percent and about 22 percent of the total mass of the rotor blade is located between about x/R=0.88 and about x/R=0.93, x corresponding to a radial location of the rotor blade measured from the axis of rotation.

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 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: 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: 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: 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.