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Adverse yaw, present in current aircraft design, is the adverse horizontal movement around a vertical axis of an aircraft; the yaw opposes the direction of a turn. As an aircraft turns, differential drag of the left and right wings while banking contributes to aircraft yaw. Proverse yaw&#8212;yawing in the same direction as a turn&#8212;would optimize aircraft performance. Initial results from flight experiments at Armstrong demonstrated that this wing design unequivocally established proverse yaw. This wing design further reduces drag due to lift at the same time. <strong>How It Works</strong> The Armstrong team (supported by a large contingent of NASA Aeronautics Academy interns) built upon the 1933 research of the German engineer Ludwig Prandtl to design and validate a scale model of a non-elliptical loaded wing that reduces drag and increases efficiency. The key to the innovation is reducing the drag of the wing through use of an alternative bell-shaped spanload, as opposed to the conventional elliptical spanload. To achieve the bell spanload, designers used a sharply tapered wing, with 12 percent less wing area than the comparable elliptical spanload wing. The new wing has 22 percent more span and 11 percent less area, resulting in an immediate 12 percent drag reduction. Furthermore, using twist to achieve the bell spanload produces induced thrust at the wing tips, and this forward thrust increases when lift is increased at the wingtips for roll control. The result is that the aircraft rolls and yaws in the same direction as a turn, eliminating the need for a vertical tail. When combined with a blended-wing body, this approach maximizes aerodynamic performance, minimizes weight, and optimizes flight control. <strong>Why It Is Better</strong> Conventional aircraft make use of elliptical loaded wings to minimize drag. However, achieving aircraft stability and control in conventional elliptical wings produces a strong adverse yaw component in roll control (i.e., the aircraft will yaw the opposite direction with application of roll control). Therefore, a vertical tail or some other method of direct yaw control is required, such as split elevons for use as drag rudders. The use of elliptical wings also results in a suboptimal amount of structure to carry the integrated wing bending moment. Adopting the bell-shaped spanload change results in an immediate 12 percent drag reduction. In addition, optimization of the overall aircraft configuration is projected to achieve additional significant overall performance increases.

Fluid lensing exploits optofluidic lensing effects in two-fluid interfaces. When used in such interfaces, like air and water, coupled with computational imaging and a unique computer vision-processing pipeline, it not only removes strong optical distortions along the line of sight, but also significantly enhances the angular resolution and signal-to-noise ratio of an otherwise underpowered optical system. As high-frame-rate multi-spectral data are captured, fluid lensing software processes the data onboard and outputs a distortion-free 3D image of the benthic surface. This includes accounting for the way an object can look magnified or appear smaller than usual, depending on the shape of the wave passing over it, and for the increased brightness caused by caustics. By running complex calculations, the algorithm at the heart of fluid lensing technology is largely able to correct for these troublesome effects. The process introduces a fluid distortion characterization methodology, caustic bathymetry concepts, Fluid Lensing Lenslet Homography technique, and a 3D Airborne Fluid Lensing Algorithm as novel approaches for characterizing the aquatic surface wave field, modeling bathymetry using caustic phenomena, and robust high-resolution aquatic remote sensing. The formation of caustics by refractive lenslets is an important concept in the fluid lensing algorithm. The use of fluid lensing technology on drones is a novel means for 3D imaging of aquatic ecosystems from above the water's surface at the centimeter scale. Fluid lensing data are captured from low-altitude, cost-effective electric drones to achieve multi-spectral imagery and bathymetry models at the centimeter scale over regional areas. In addition, this breakthrough technology is developed for future in-space validation for remote sensing of shallow marine ecosystems from Low Earth Orbit (LEO). NASA's FluidCam instrument, developed for airborne and spaceborne remote sensing of aquatic systems, is a high-performance multi-spectral computational camera using Fluid lensing. The space-capable FluidCam instrument is robust and sturdy enough to collect data while mounted on an aircraft (including drones) over water.

The MAchine learning ESTimations for uRban Operations (MAESTRO) system is a novel approach that couples commodity sensors with advanced algorithms to provide real-time onboard local wind and kinematics estimations to a vehicle's guidance and navigation system. Sensors and computations are integrated in a novel way to predict local winds and promote safe operations in dynamic urban regions where Global Positioning System/Global Navigation Satellite System (GPS/GNSS) and other network communications may be unavailable or are difficult to obtain when surrounded by tall buildings due to multi-path reflections and signal diffusion. The system can be implemented onboard an Unmanned Aerial Systems (UAS) and once airborne, the system does not require communication with an external data source or the GPS/GNSS. Estimations of the local winds (speed and direction) are created using inputs from onboard sensors that scan the local building environment. This information can then be used by the onboard guidance and navigation system to determine safe and energy-efficient trajectories for operations in urban and suburban settings. The technology is robust to dynamic environments, input noise, missing data, and other uncertainties, and has been demonstrated successfully in lab experiments and computer simulations.

This CLAS-ACT is a lightweight, active phased array conformal antenna comprised of a thin multilayer microwave printed circuit board built on a flexible aerogel substrate using new methods of bonding. The aerogel substrate enables the antenna to be fitted onto curved surface. NASA's prototype operates at 11-15 GHz (Ku-band), but the design could be scaled to operate in the Ka-band (26 to 40 GHz). The antenna element design incorporates a dual stacked patch for wide bandwidth to operate on both the uplink and downlink frequencies with a common aperture. These elements are supported by a flexible variant of aerogel that allows the material to be thick in comparison to the wavelength of the signal with little to no additional weight. The conformal antenna offers advantages of better aerodynamics for the airframe, and potentially offers more physical area to either broadcast further distances or to broadcast at a higher data rate. The intended application for this antenna is for UAVs that need more than line of sight communications for command and control but cannot accommodate a large satellite dish. Examples may be UAVs intended for coastal monitoring, power line monitoring, emergency response, and border security where remote flying over large areas may be expected. Smaller UAVs may benefit greatly from the conformal antenna. Another possible application is a UAV mobile platform for Ku-band satellite communication. With the expectation that 5G will utilize microwave frequencies this technology may be of interest to other markets outside of satellite communications. For example, the automotive industry could benefit from a light weight conformal phased array for embedded radar. Also, the CLAS-ACT could be used for vehicle communications or even vehicle to vehicle communications.