System for Flight Control of Extremely Fast (Hypersonic) Aircraft

NASA’s MHD patch technology is composed of two electrodes positioned a prescribed distance apart recessed into angled channels on the surface of the TPS of an aircraft or spacecraft and an electromagnetic coil placed directly below the electrodes with the magnetic field protruding out of the surface. Note that the recessed/angled MHD patch described here is a special version of the original MHD patch described in LAR-TOPS-363. During hypersonic flight, the conductive ionizing atmospheric flow over the surface permits current to flow between the two electrodes. This current is harnessed to power the electromagnet which in turn generates strong Lorentz forces that augment lift and drag forces for guidance, navigation, and control of the craft. Alternatively, the current can be used to charge a battery. Changing the size of the MHD patch (e.g., the length or distance between the electrodes), the strength of the electromagnet, or the direction of the magnetic field enables tuning of generated forces for a given craft design. Multiple MHD patches can be leveraged on a single craft. In-silico evaluation of the non-recessed, non-angled MHD patch technology on select aeroshell designs for mock entry into planetary atmospheres has been performed. A single 1m2 MHD patch exerts forces up to 200 kN under simulated Neptune atmosphere entry that can be used to control a craft.

This novel flightpath control system exploits the dihedral effect to control the bank angle of the vehicle by modulating sideslip (Figure 1). Exploiting the dihedral effect, in combination with significant aerodynamic forces, enables faster bank accelerations than could be practically achieved through typical control strategies, enhancing vehicle maneuverability. This approach enables vehicle designs with fewer control actuators since roll-specific actuators are not required to regulate bank angle. The proposed control method has been studied with three actuator systems (figure below), Flaps Control System (FCS); Mass Movement Control System (MMCS); and Reaction Control System (RCS). FCS consists of a flap configuration with longitudinal flaps for independent pitch control, and lateral flaps generating yaw moments. The flaps are mounted to the shoulder of the vehicles deployable rib structure. Additionally, the flaps are commanded and controlled to rotate into or out of the flow. This creates changes in the vehicles aerodynamics to maneuver the vehicle without the use of thrusters. MMCS consists of moveable masses that are mounted to several ribs of the DEV heatshield, steering the vehicle by shifting the vehicles Center of Mass (CoM). Shifting the vehicles CoM adjusts the moment arms of the forces on the vehicle and changes the pitch and yaw moments to control the vehicles flightpath. RCS thrusters are mounted to four ribs of the open-back DEV heatshield structure to provide efficient bank angle control of the vehicle by changing the vehicles roll. Combining rib-mounted RCS thrusters with a Deployable Entry Vehicle (DEV) is expected to provide greater downmass capability than a rigid capsule sized for the same launch

The advantages displayed by Glenn's AIE stem from a number of novel design concepts, centered on an annular discharge chamber with a set of annular ion optics. The annular discharge chamber increases the effective anode surface area for electron collection as compared to a conventional cylindrically shaped ion thruster of equivalent beam area. With this increased surface area, the AIE can operate at higher discharge currents and therefore high beam currents, thereby yielding a significantly increased (3x) thrust density. An annular-geometry flat electrode can be added to enable higher-perveance designs with even higher thrust densities, with improved F/P and efficiencies compared to more conventional, spherically domed electrodes. In addition, Glenn's design allows the neutralizer cathode assembly (NCA) to be placed in a central position within the annulus, which not only eliminates the cantilevered-outboard NCA used in most conventional ion thrusters but also enables a shared gimbal platform. These benefits make manufacturing the AIE simpler as well as allowing more compact engine designs. All of these advantages add up to an electric propulsion machine that yields superior performance over the entire Isp range, making the AIE attractive for next-generation SEP vehicles. Glenn's technological advance enables spacecraft to travel farther, faster, and more cheaply than with any other propulsion technology - with clear benefits for NASA and commercial space applications.

The new transparent EDS technology is lighter, easier to manufacture, and operates at a lower voltage than current transparent EDS technologies. The coating combines an optimized electrode pattern with a vapor deposited protective coating of SiO2 on top of the electrodes, which replaces either polymer layers or manually adhered cover glass (see figure on the right). The new technology has been shown to achieve similar performances (i.e., over 90% dust clearing efficiency) to previous technologies while being operated at half the voltage. The key improvement of the new EDS coating comes from an innovative method to successfully deposit a protective layer of SiO2 that is much thinner than typical cover glass. Using vapor deposition enables the new EDS to scale more successfully than other technologies that may require more manual manufacturing methods. The EDS here has been proven to reduce dust buildup well under vacuum and may be adapted for terrestrial uses where cleaning is done manually. The coatings could provide a significant improvement for dust removal of solar cells in regions (e.g., deserts) where dust buildup is inevitable, but water access is limited. The EDS may also be applicable for any transparent surface that must remain transparent in a harsh or dirty environment. The related patent is now available to license. Please note that NASA does not manufacturer products itself for commercial sale.

The invention uses the superconducting "proximity effect" and/or the "inverse proximity effect" to form a spatially varying order parameter. When designed to expel magnetic flux from a region of space, the proximity effect(s) are used in concert to make the superconducting order parameter strongly superconducting in the center and more weakly superconducting toward the perimeter. The shield is then passively cooled through the superconducting transition temperature. The superconductivity first nucleates in the center of the shielding body and expels the field from that small central region by the Meissner effect. As the sample is further cooled the region of superconducting order grows, and as it grows it sweeps the magnetic flux lines outward.