ALBERT

Description: In order to tackle and solve the prediction problem of the lifetime of Li-ion batteries, it is essential to have awareness of the current state and health of the battery pack. To be able to accurately predict the future state of any system, one must possess knowledge of its current and future operations. Using derived models of the current and future system behavior, a model-based prognostics approach can be implemented as a solution to the prediction problem. As more and more autonomous electric vehicles progressively emerge in our daily life, a very critical challenge lies in accurate prediction of remaining useful life of the systems/subsystems. Batteries, power electronics conditioning systems, and motors are integrated to form the powertrain in electric vehicles; one of the most critical systems. In the case of electric aircrafts, computing remaining flying time is critical for safety, since an aircraft that runs out of power (battery charge) while in the air will eventually lose control leading to catastropheThis presentation covers a physics-based modeling approach implemented for case studies in capacitor and battery prognostics which are an integral part of an electrical powertrain system. The general approach of model-based prognostics will be examined as a potential solution for safety critical problems related to battery state of charge and state of health.

Description: Emerging power metal-oxide semiconductor field-effect transistor (MOSFETs) based on silicon carbide and gallium nitride technology are finding widespread use in many electronic applications such as motor control and DC/DC converters due to their higher voltage, higher temperature tolerance, and higher frequency switching capabilities. To utilize these power devices and to meet circuit/system compactness, modularity, and operational functionality, gate drivers that provide unique attributes, such as fast switching and high-current handling capability, are needed. In addition, power systems geared for use in space mission applications require on-board devices to withstand exposure to extreme temperatures and wide thermal swings. Very little data, however, exist on the performance of such devices and circuits under extreme temperatures. In this work, the performance of a high-speed gate driver with potential use in controlling power-level transistors was evaluated under extreme temperatures and thermal cycling. The investigations were carried out to assess performance for potential use of this device in space exploration missions under extreme temperature conditions.

Description: The NASA Design and Analysis of Rotorcraft (NDARC) software is an aircraft system analysis tool that supports both conceptual design efforts and technology impact assessments. The principal tasks are to design (or size) a rotorcraft to meet specified requirements, including vertical takeoff and landing (VTOL) operation, and then analyze the performance of the aircraft for a set of conditions. For broad and lasting utility, it is important that the code have the capability to model general rotorcraft configurations, and estimate the performance and weights of advanced rotor concepts. The architecture of the NDARC code accommodates configuration flexibility, a hierarchy of models, and ultimately multidisciplinary design, analysis, and optimization. Initially the software is implemented with low-fidelity models, typically appropriate for the conceptual design environment. An NDARC job consists of one or more cases, each case optionally performing design and analysis tasks. The design task involves sizing the rotorcraft to satisfy specified design conditions and missions. The analysis tasks can include off-design mission performance calculation, flight performance calculation for point operating conditions, and generation of subsystem or component performance maps. For analysis tasks, the aircraft description can come from the sizing task, from a previous case or a previous NDARC job, or be independently generated (typically the description of an existing aircraft). The aircraft consists of a set of components, including fuselage, rotors, wings, tails, and propulsion. For each component, attributes such as performance, drag, and weight can be calculated; and the aircraft attributes are obtained from the sum of the component attributes. Description and analysis of conventional rotorcraft configurations is facilitated, while retaining the capability to model novel and advanced concepts. Specific rotorcraft configurations considered are single-main-rotor and tail-rotor helicopter, tandem helicopter, coaxial helicopter, and tiltrotor. The architecture of the code accommodates addition of new or higher-fidelity attribute models for a component, as well as addition of new components.

Description: NASA Ames Research Center (ARC) Aeromechanics Branch hosted more than 60 interns this summer and focused their energies on studying the future of vertical flight. This is the second of two reports from this past years summer interns.

Description: No abstract available

Description: An analysis was set up to model the temperature of the advanced modular power system (AMPS) power distribution cards when installed within the electronics enclosure case. The analysis was used to determine the steady-state temperature distribution of the cards within the case. To verify the analysis, an experiment was set up and conducted to simulate the operation of the cards within the enclosure. Four tests were conducted. The tests varied the position of the cold plate and evaluated the use of a thermal compound to reduce the contact resistance between the joints within the thermal path between the cards and the cold plate. Three of the four cases examined showed very good agreement between the analysis and the experiment with a less than 1-percent variation in the predicated temperatures determined through the analysis and the experimentally derived temperatures. In the remaining case, the difference between the analysis and experiment was approximately 12 percent. Both the experiment and analysis showed that the modular power conditioning cards can be maintained within their desired maximum operating temperature range of 40 to 45 C through thermal conduction to a cold plate when operating with their estimated maximum heat output of 16 W per card.

Description: This presentation illustratively communicates how to SPICE model silicon carbide (SiC) SiC junction field effect transistors (JFETs) for designing circuits for NASA GRC's upcoming prototype fabrication of SiC JFET IC Version 12.

Description: This presentation illustratively communicates integrated circuit (IC) mask design and layout rules for NASA GRC's upcoming prototype fabrication of SiC JFET IC Version 12.

Description: This presentation provides an overview of common mode conducted emissions (CMCE) measurements on power and signal cables. The presentation focuses on how such measurements directly apply to electromagnetic compatibility at the system level and provides a discussion of different techniques for performing them correctly and accurately.

Description: Vacuum airships fueled by renewable energy would reduce reliance on fossil fuel-based modes of transport, lessen the need for limited and non-renewable lifting gases, and can be achieved using novel manufacturing techniques for ultra-light, discrete lattice material systems.The Discrete Lattice Material Vacuum Airships (DLMVA) system combines novel material science and manufacturing technologies for new modes of mass transportation, resulting in a disruptive approach to reduce national resource consumption and emissions. Through the use of high performance building block elements, modular, scalable and extensible aircraft can be rapidly assembled into positive net-buoyancy systems utilizing a vacuum instead of a lifting gas. By using architected lattice material principles, show that lattice materials can overcome stability limitations of previous vacuum balloon designs. Additionally, we show that lattice vacuum balloons are strength limited, rather than stability limited. As a result,airborne infrastructure can be developed to support the proliferation of modern systems such as e-commerce and distributed communications, while simultaneously reducing dependence on finite, non-renewable, emission-heavy resources.

Description: NASA's Unmanned Aircraft Systems Integration into the National Airspace System (UAS in the NAS) project examines the technical barriers associated with the operation of UAS in civil airspace. For UAS, the removal of the pilot from onboard the aircraft has eliminated the ability of the ground-based pilot in command (PIC) to use out-the-window visual information to make judgements about a potential threat of a loss of well clear with another aircraft. NASA's Phase 1 research supported the development of a Detect and Avoid (DAA) system that supports the ground-based pilot's ability to detect potential traffic conflicts and determine a resolution maneuver, but existing display/alerting requirements did not account for multiple UAS control (1:N). Demands for increased scalability of UAS in the NAS operations are expected to create a need for simultaneous control of UAs, and thus, a new DAA HMI design will likely be necessary. Previous research, however, has found performance degradations as the number of vehicles under operator control has increased. The purpose of the current human-in-the-loop (HITL) simulation was to examine the viability of 1:N operations with the Phase 1 DAA alerting and guidance. Sixteen UAS pilots flew three scenarios with varying number of UAs under their control (1:1, 1:3, 1:5). In addition to their supervisory and sensor mission responsibilities, pilots were to utilize the DAA system to remain DAA well clear (DWC) during scripted conflicts of mixed severity. Measured response times, separation performance, mission task data, and subjective feedback were collected to assess how the multi-UAS control configuration impacted pilots' ability to maintain DAA well clear and perform the mission tasks. Overall, the DAA system proved surprisingly adaptive to multi-UAS control for preventing losses of DAA well clear (LoDWC). The findings suggest that, while multi-UAS operators are able to maintain safe separation (DWC) from other traffic, their ability to efficiently perform missions drastically decreases with their number of controlled vehicles. Pilot feedback indicated that, for this context, the use of automation support tools for completing and managing mission tasks would be appropriate and desired, especially for ensuring efficient use of assets. Finally, human-machine interface (HMI) design considerations for multi-UAS operations are discussed.

Description: No abstract available

Description: A computational framework to support the quantification of system uncertainties and sensitivities for rotorcraft applications is presented using the NASA Design and Analysis of Rotorcraft (NDARC) conceptual sizing tool. A 90 passenger conceptual tiltrotor configuration was used for case demonstration in the modeling of uncertainties in NDARCs emission module. A non-intrusive forward propagation uncertainty quantification approach was applied to ensemble simulations using a Monte Carlo methodology with stratified Latin hypercube sampling. An off-the-shelf software, DAKOTA, which supports trade studies and design space exploration, including optimization, surrogate modeling and uncertainty analysis was used to address the research goals. A toolsuite was further developed incorporating DAKOTA with automated design processes and methods using function wrappers to execute program routines including support for data post-processing. Uncertainties in rotorcraft emissions modeling using the Average Temperature Response metric for a set mission profile were studied. It was shown that for the current study, using the base-line best estimate modeling parameters for the Average Temperature Response metric, NDARC under-estimates the effects of emissions when compared with results from Monte Carlo simulations. A global sensitivity analysis was further undertaken to quantify the contribution of the various emission species on output sensitivity, hence uncertainty. The work demonstrates that the developed toolsuite is robust and will support the quantification of system uncertainties and sensitivities in future rotorcraft design efforts.

Description: This presentation is an overview of research being conducted by NASA and the AFRL, including recent successes and failures.

Description: The UAS in the NAS project Flight Test 6 (FT6) campaign scheduled for FY19Q3 will evaluate the proficiency of a Honeywell DAPA-Lite Radar installed on a Tiger Shark unmanned vehicle to detect the presence of air traffic operating in its vicinity. A 3D printed radome will be manufactured for the front of the Tiger Shark to enclose the radar during FT6 operations. The DAPA-Lite radar operates in the 24.5 GHz frequency band. Material properties of 3D printer filaments are widely available for the mechanical and thermal properties, but limited knowledge exists on the electrical properties for radome applications and no data was found to correspond at the 24.5 Ghz frequency band. To minimize project risk associated with the radome performance, transmissivity and reflectivity measurements were conducted on two candidate 3D printed dielectric material filaments (Ultem 1010 Natural and Ultem 9085 Black) and two thicknesses of a solid laminate (Ultem 1000) material. The 3D printed Ultem coupons were tested shortly after being printed and again 8 months later to examine ageing effects of the open cell structure. This paper presents the transmissivity and reflectivity measurement results collected on the Ultem coupons and concludes the 3D printed 1010 Natural coupon is a suitable candidate filament for radome applications at 24.5 GHz. The design of the structures open cell matrix has a significant impact on the materials surface reflectivity.

Description: NASA Electronic Parts and Packaging (NEPP) Program Overview and Technology Highlights The NEPP Program provides NASA's leadership for developing and maintaining guidance for the screening, qualification, test, and reliable use of electrical, electronic, and electromechanical parts by NASA, in collaboration with other government agencies and industry. The NASA Electronic Parts Assurance Group (NEPAG) is a core portion of NEPP. This presentation highlights key focus areas for 2019.

Description: The goal of this study was to perform an independent investigation of single event destructive and transient susceptibility of the Microsemi RTG4 device. The devices under test were the Microsemi RTG4 field programmable gate array (FPGA) Rev C. The devices under test will be referenced as the DUT or RTG4 Rev C throughout this document. The DUT was configured to have various test structures that are geared to measure specific potential susceptibilities of the device. DesignDevice susceptibility was determined by monitoring the DUT for Single Event Transient (SET) and Single Event Upset (SEU) induced faults by exposing the DUT to a heavy ion beam. Potential Single Event Latch-up (SEL) was checked throughout heavy-ion testing by monitoring device current.

Description: The first years effort identified sampling and interviewing as the principal risks to assessment of prompt reactions to overflights producing low-amplitude sonic booms. It also 1) established the utility of geo-information system-based route planning for LBFD flight missions, 2) developed and demonstrated a prototype of a geographically-distributed, Internet-enabled instrumentation system capable of wide-area tracking of LBFD aircraft in near-real time. The latter system permits synchronizing the conduct of interviews in multiple overflown communities with arrival times of shock waves at interviewing sites; and of measuring, archiving, and processing their acoustic signatures. Means were also recommended for constructing representative, telephone-based samples of eligible respondents living in households within carpet boom corridors adjacent to LBFD flight tracks, and for conducting interviews with cross-sectional (independent) samples of such respondents about their prompt reactions to exposure to low-amplitude sonic booms. A detailed study design was prepared and accepted by NASA for a set of single-contact attempt telephone interviews with a nationally representative sample of households. The study design focused on testing automated and live agent interview completion rates obtainable without callbacks. A minimal (two monitoring station) version of the aircraft tracking system was built and installed near a civil airport in a successful demonstration of the systems ability to detect and track aircraft movements. The field exercise also demonstrated the ability of the system to capture the acoustic emissions of departing aircraft, and to serve aircraft position and sound level information to remote, geographically-distributed analysts in near-real time. Upon approval of OMB and IRB of the detailed study plan, a stratified, nationally representative sample of landline and wireless telephone-subscribing households was constructed. A total of 12,734 telephone interview contact attempts of the sort required by a straightforward cross-sectional study design were then made. These contact attempts demonstrated the impracticality of conducting a time-critical, cross-sectional study of prompt community response to low-amplitude sonic booms by means of independent (single contact attempt per respondent for each LBFD flight mission) telephone samples of respondents. The observed interview completion rates for these single telephone contact attempts were so low (~ 1% to 3% for automated and live agent interviews, respectively) that: 1) the representativeness of collected opinions would be susceptible to intuitive challenge as inadequate, even absent conclusive evidence of non-representativeness. Refuting challenges to representativeness would have to demonstrate that the composition of the actual sample did not differ from that of the target population, a task that is tantamount to proving a negative; 2) the information required to refute allegations of non-representativeness would require a questionnaire considerably lengthier than that required simply to determine the prevalence of boom-induced startle and annoyance. Such a questionnaire would have to inquire about potentially sensitive and intrusive matters, including respondents age, gender, education, employment, home ownership, income, ethnicity, family size, and other demographic factors; and 3) unreasonable numbers of attempts would be required to re-contact households with unsuccessful initial contact attempts, given the limited time available for doing so. For example, if about 500 completed interviews were desired in a supersonically overflown community, approximately 50,000 automated interview attempts would have to be made within ten to fifteen minutes of each LBFD overflight. Such large numbers of contact attempts could well exceed the numbers of households available for interview in areas of similar boom exposure levels in some communities near LBFD flight tracks. Such large numbers of interviews could be cost-effectively undertaken only by means of automated (i.e., outgoing interactive voice response) interviewing, a data collection method ill-suited for complex and sensitive questionnaire items. The infeasibility of independent sampling for evaluating prompt responses to LBFD overflights in a cross-sectional study is due in large part to simple non-response: that is, potential respondents particularly those contacted on wireless telephones refusing to answer calls with unfamiliar caller IDs. It is also due in part, however, to 1) the lack of time to attempt to contact the same respondent more than once within a few minutes after the arrival of a shock wave at the respondents location; and 2) the need to place calls during weekday/daytime hours, when response rates are notably lower than during evenings and weekends. Despite the poor interview completion rates achieved under the above constraints, cross sectional assessments of delayed reactions to LBFD overflights could still be feasible, if multiple attempts could be made to contact respondents during evening and weekend time periods, over extended time periods. Detailed plans for a longitudinal (panel) sample were developed as an alternative to a cross sectional sample design.

Description: A full-scale isolated proprotor test was recently conducted in the USAF National Full-Scale Aerodynamics Complex (NFAC) 40- by 80-Foot Wind Tunnel at NASA Ames. The test article was a 3-bladed research rotor derived from the right-hand rotor of the AW609. For this test, the NASA Tiltrotor Test Rig (TTR) and rotor were installed in the 40- by 80-Foot Wind Tunnel. This paper covers the analyses and testing done to prepare for a safe entry. Included are brief descriptions of the following: NASTRAN models of the TTR, ground vibration tests of the TTR (and resulting modal data), loads analyses, and stability predictions using the comprehensive analysis CAMRAD II. The evolution of these analyses from early in the TTR program until the initiation of actual testing is also discussed. The intent is to show how all of these efforts were integrated to ensure a successful test. This paper includes stability predictions based on NASTRAN modal data and worst-case damping test data. The stability predictions covered all test conditions: hover, cruise (airplane mode), conversion, and helicopter mode. The predictions showed that the TTR and rotor are stable within the test envelope.

Description: Microsemi (Microchip) RTG4 embedded triple modular redundant (TMR) phase-locked-loop (PLL) SEU data is presented. SEU data analysis includes: 1) Evaluation of heavy-ion beam angular effects (rectangular parallel pipe (RPP) or no RPP), 2) Importance of finding linear energy transfer (LET) onset (L0), 3) Comparison of prediction rate techniques.

Description: No abstract available

Description: With the development of wide band-gap (WBG) technology, the switching speed of power semiconductor devices is increased, which makes circuits more sensitive to parasitics. For three-level active neutral point clamped (3L-ANPC) converters, the over-voltage of non-conducting switches can be an issue. This paper analyzes the multiple commutation loops in 3L-ANPC converter and summarizes the impact factors of the over-voltage for the non-conducting switch. It is found that the nonlinearity of the output capacitance of the device can significantly influence the over-voltage. A simple control without introducing any additional hardware circuit is proposed to attenuate the impact of the nonlinearity. With the proposed control, the peak over-voltage of the non-conducting switch can be reduced significantly. Multi-pulse test is conducted for a 3L- ANPC converter built with silicon carbide (SiC) MOSFETs. The testing results show that the peak over-voltage decreases from 892 V to 624 V with the proposed control. More detailed analysis and experimental results will be provided in the final paper.

Description: This presentation illustratively communicates how to SPICE model integrated silicon carbide (SiC) SiC resistors for designing circuits for NASA GRC's upcoming prototype fabrication of SiC JFET IC Version 12.

Description: Nuclear fission power offers an attractive alternative to solar electric or radioisotope power systems for certain applications on the Moon, Mars, and deep space science missions. The advantages of independence from solar irradiance, high energy density, and abundance of fuel allow fission power systems to enable novel, high power mission architectures. While NASA has had numerous fission power programs throughout its history, few have gone far beyond the design phase. The recent test campaign called the Kilopower Reactor Using Stirling Technology project (KRUSTY) focused on a low power, kilowatt-scale design for simplicity and reduced cost, with the driving motivation to perform a full nuclear hardware prototype test. Following the successful completion of the KRUSTY nuclear hardware test in March of 2018, NASA has begun the formulation process for a Technology Demonstration Mission (TDM) using the Kilopower reactor technology. In support of NASA's lunar surface initiatives, the Kilopower TDM will target a 1-3 kW fission electric power system that can survive the lunar night and operate for one year. The system will be heavily influenced by the KRUSTY reactor design, using a solid Uranium metal core with high temperature heat pipes and Stirling engine power conversion. During this formulation phase, continued engineering efforts are ongoing to improve heat transfer efficiency in the system, examine fission radiation damage effects, and begin to address the thermal and structural requirements of a Kilopower flight system.

Description: After testing grooved over-the-rotor acoustic casing treatments on a turbofan rotor, a follow-on study was performed to investigate the effect of flow on grooved acoustic liners. The experiment was performed to understand the scaling of acoustic liner absorption with grazing flow and investigate a potential noise source from grooved acoustic liners. Acoustic liner absorption and reflection characteristics were quantified by examining the reduction in amplitude of a plane wave traveling over 2 inch liners with grazing flow. For all liners tested, as the grazing flow Mach number is increased, the absorption curves broadened and the frequency of peak absorption decreased. Grazing flow over a series of grooves was found to generate resonances up to 152 dB sound pressure level. Adding acoustic treatment to the bottom of these grooves was found to reduce the magnitude of this resonance by up to 10 dB sound pressure level and increase its frequency by up to 10%. The quantification of the grazing flow effect and identification of a mechanism behind the noise penalty from the prior turbofan rotor experiment will aid in the design of future over-the-rotor treatments.

Description: This presentation covers recent process improvements regarding environmental parameters, w.r.t convection, and future plans for thermal models.

Description: Presentation will cover new high level requirement changes for gondolas launched by Columbia Scientific Balloon Facility (CSBF), and discuss recommendations for the design and design process.

Description: No abstract available

Description: NASA Electronic Parts and Packaging (NEPP) Program Overview Mission Statement: Provide NASA's leadership for developing and maintaining guidance for the screening, qualification, test, and reliable use of EEE parts by NASA, in collaboration with other government agencies and industry. The NASA Electronic Parts Assurance Group (NEPAG) is a core portion of NEPP.

Description: This paper describes an aero-structural modeling method for the Transonic Truss-Braced Wing (TTBW) aircraft using VSPAERO. A vortex-lattice model of the TTBW aircraft is developed, and a transonic and viscous flow correction method is implemented in the VSPAERO models to account for transonic and viscous flow effects. A correction method for the wing-strut interference aerodynamics is developed and applied to the VSPAERO solver. Also, a structural dynamic finite-element model of the TTBW aircraft is developed. This finite-element model includes the geometric nonlinear effect due to the tension in the struts which cause a deflection dependent nonlinear stiffness. The VSPAERO models are coupled to the finite-element model to provide a rapid capability for aero-structural modeling and flutter analysis. A flight-optimized jig twist model is being developed and will be applied for the purpose of generating a full flight dynamic model of the TTBW aircraft.

Description: A multi-layer wireless sensor construct is provided. The construct includes a first dielectric layer adapted to be attached to a portion of a first surface of an electrically-conductive material. A layer of mu metal is provided on the first dielectric layer. A second dielectric layer is provided on the layer of mu metal. An electrical conductor is provided on the second dielectric layer wherein the second dielectric layer separates the electrical conductor from the layer of mu metal. The electrical conductor has first and second ends and is shaped to form an unconnected open-circuit that, in the presence of a time-varying magnetic field, resonates to generate a harmonic magnetic field response having a frequency, amplitude and bandwidth.

Description: This student poster describes their experiences during the current intern period.

Description: The Icing Research Tunnel (IRT) at NASA Glenn Research Center follows the recommended practice for icing tunnel calibration outlined in SAE's ARP5905 document. The calibration team has followed the schedule of a full calibration every five years with a check calibration done every six months following. The liquid water content of the IRT has maintained stability within in the specifications presented to customers that the variation is within +/- 10% of the calibrated, target measurement. With recent measurements and instrumentation errors, a more thorough assessment of error source was desired. By constructing statistical process control charts, the ability to determine how the instrument varies in the short term, mid term, and long term was gained. The control charts offer a view of instrument error, facility error, or installation changes. It was discovered that there was a shift from target to mean baseline thus leading to the study of the overall capability indices of the liquid water content measuring instrument to perform within specifications defined in the IRT. This presentation describes data processing procedures for the Multi-Element Sensor in the IRT, including collision efficiency corrections, canonical correlation analysis, Chauvenet's Criterion for rejection of data, distribution check of data, and mean, median and mode for construction of control charts. Further data is presented to describe the repeatability of the IRT with the Multi-Element Sensor and the ability to maintain a stable process for the defined calibration schedule.

Description: ISO-26262, the road vehicle functional safety standard, underwent a major overhaul that was released in December 2018. Radiation effects, and single-event effect (SEE) hazards in particular, play an important role in autonomous vehicle safety. This connection will only increase as the level of driving automation goes from "hands off," to "eyes off," to "mind off." This translates to increased coupling with space climate and weather in addition to other traditional terrestrial radiation sources like thorium and uranium contamination in process and packaging materials. We will focus on autonomous vehicle radiation effects and present both benefits and challenges to the space weather and radiation engineering communities.

Description: NASA's all-electric X-57 airplane will utilize 14 electric motors, of which 12 are exclusively for lift augmentation during takeoff and landing. This report covers the design and development process taken to create an open reference model representative of the 12 lift augmenting motors. A combined worst case scenario was used as the design point, which represents the simultaneously occurring worst case aspects of thermal, static stress, electromagnetic, and rotor dynamic conditions. This work also highlights the tightly coupled nature of aerospace electric motor design, requiring constant iteration between all disciplines involved. Further adding to the uniqueness is the cooling method, which is limited to nacelle skin forced convection cooling only, no internal air flow is permitted. The stator outer diameter limit of 156.45 mm greatly impacts the degree of coupling between the electromagnetic design with the thermal analysis. The permanent magnet synchronous motor developed here operates between 385 V and 538 V, at a peak current of 50 A. Detailed electromagnetic, thermal, static load, and rotordynamic analysis was completed for this electric motor; all of which are required for a full design. The rotordynamic analysis took into consideration the motor housing which is designed specifically for this motor. The final electric motor has a mass of 2.34 kg, produces 24.1 Nm of torque with a specific power of 5.56 kW/kg, and has an efficiency of 96.61% at the combined worst case design point.

Description: Adding an ACTE II (Adaptive Compliant Trailing Edge II) closeout summary to the ACTE II TechPort page.

Description: An integrated circuit (IC) chip with a self-contained fluid sensor and method of making the chip. The sensor is in a conduit formed between a semiconductor substrate and a non-conductive cap with fluid entry and exit points through the cap. The conduit may be entirely in the cap, in the substrate or in both. The conduit includes encased temperature sensors at both ends and a central encased heater. The temperature sensors may each include multiple encased diodes and the heater may include multiple encased resistors.

Description: A high-voltage power transmission system is used as an extremely large antenna to extract spatiotemporal space, physical, and geological information from geomagnetically induced currents (GIC). A differential magnetometer method is used to measure GIC and involves acquiring line measurements from a first fluxgate magnetometer under a high-voltage transmission line, acquiring natural field measurements from a reference magnetometer nearby but not under the transmission line, subtracting the natural field measurements from the line measurements, and determining the GIC-related Biot-Savart field from the difference. NASA warning and alarm systems can be triggered based on determinations of GIC amplitude levels that exceed a set threshold value.

Description: Increasing the power density and efficiency of electric machines (motors and generators) is integral to bringing Electrified Aircraft (EA) to commercial realization. To that end an effort to create a High Efficiency Megawatt Motor (HEMM) with a goal of exceeding 98% efficiency and 1.46 MW of power has been undertaken at the NASA Glenn Research Center. Of the motor components the resistive losses in the stator windings are by far the largest contributor (34%) to total motor loss. The challenge is the linear relationship between resistivity and temperature, making machine operation sensitive to temperature increases. In order to accurately predict the thermal behavior of the stator the thermal conductivity of the Litz wire-potting-electrical insulation system must be known. Unfortunately, this multi material system has a wide range of thermal conductivities (0.1 W/m-K 400 W/m-K) and a high anisotropy (axial vs transverse) making the prediction of the transverse thermal conductivity an in turn the hot spot temperatures in the windings is difficult. In order to do this a device that simulates the thermal environment found in the HEMM stator was designed. This device is not unlike the motorettes (little motors) that are described in IEEE standards for testing electrical insulation lifetimes or other electric motor testing. However, because the HEMM motor design includes significant rotor electrical and thermal considerations the term motorette was not deemed appropriate. Instead statorette (or little stator) was adopted as the term for this test device. This paper discussed the design, thermal heat conjugate analysis (thermal model), manufacturing and testing of HEMM's statorette. Analysis of the results is done by thermal resistance network model and micro thermal model and is compared to analytical predictions of thermal conductivity of the insulated and potted Litz wire system.

Description: This project details the design and analysis of a structure to replace the interface of the P-3B nadir port with an optimized interface for science installations. A new nadir port plug has been designed to replace the OEM (Original Equipment Manufacturer) plug (Lockheed PN 910169) currently used in Nadir ports 1 and 2 on the NASA P-3B aircraft. The plug consists of a milled frame that can be outfitted with customizable flat plates to meet a broad range of science needs. The frame slides into place using the existing P-3B rail system using a lever and tie-rod assembly. The seal interface will contact the Fuselage skin of the aircraft and consists of a bulb E-seal that is riveted around the perimeter of the frame. The flat plate (20 inches x 31 inches) provides a large profile that can be outfitted based on science mission goals and requirements to attach multiple instruments. This is a significant increase to the aircraft capability. Previously, the OEM plug had to be modified to hold very small plates, windows, or instruments limiting the use of the ports.There were several challenges for this project that included a constrained schedule, lack of historical references, and reverse engineering. The unusually tight schedule for design, manufacture, and install limited potential approaches. In addition, design of a new interface to replace the existing plug, on an aircraft designed in the 1960's by Lockheed for the Navy with little to no documentation, required substantial reverse engineering. In order to accomplish this, a suitable method to determine interface requirements with the aircraft had to be solved. After several iterations, the solution was to implement laser scanning techniques to scan the aircraft and the OEM plug and generate a 3D model to capture the design envelope. The structure is designed to maintain a positive margin of safety when subjected to the inertial, pressure, and aerodynamic load requirements for an external installation on the P-3B, as described in the Wallops' P-3B Design Requirements 548-RQMT-0001 Rev. A . A finite element model is created in FEMAP (Finite Element Modeling And Postprocessing) and is run through NX Nastran solver to analyze the structure. After several iterations of analysis, the structure was enveloped to hold 115 pounds evenly distributed on the plate.

Description: Solar neutrons are the tell-tale of highly energetic processes (e.g. solar flares) at the Sun in which particle acceleration is taking place over a broad range in energy. Unlike charged radiation, neutrons escape unscathed from the ambient magnetic fields, providing a view of particle acceleration unhindered by the effects of transport. High-energy neutrons are challenging to measure with the traditional double scatter technique based on time-of-flight (ToF). This technique is limited by the finite flight path and active scintillator sizes required by small satellite platforms. The new SOlar Neutron TRACking (SONTRAC) concept, based on scintillating-fiber bundles, will provide high resolution imaging of fast neutrons at energies where the bulk of solar and magnetospheric neutrons resides. Recent development of the new SONTRAC instrument concept's advanced electronics and processing algorithms are presented.

Description: This presentation highlights NASA AFRCs wireless systems development plans as well as technological needs and airworthiness challenges for flight test/research applications. The presentation discusses desired wireless sensing and wireless data communication methodologies for specific aircraft areas such as wings, tail, engines, and landing gears. The presentation also provides information for potential industry partners seeking to collaborate in the development of sensors through various means as well as to verify and validate wireless sensors and systems through flight at AFRC.

Description: This report characterizes the certification practices for electric propulsion systems by modeling changes to current engine and propeller certification practices (14 CFR 23, 33 and 35 and means of compliance in standards developed by ASTM Committee F39 and F44). Industry technology paths are varied, so this report focuses on insights from the NASA X-57 Maxwell Distributed Electric Propulsion flight demonstrator system technology project. There are 122 sections of the regulation reviewed, where 28 needed tailoring or revision. A second report will examine the regulations to the X-57 system development products. A final report will describe a general regulatory gaps method for new vehicle concepts.

Description: This paper will address NASA activities to monitor and study Earth processes from long-duration unmanned aircraft systems (UAS). NASA is currently supporting both large and small UAS development and demonstration. In a follow-on to previous work, NASA Armstrong Flight Research Center is hosting test flights of a large AeroVironment solar-powered aircraft, while NASA Ames Research Center is supporting the demonstration of a light-weight solar powered aircraft by Swift Engineering. Both are designed for long duration, multi-day flight. NASA Earth Science and Aeronautics researchers have been involved in the development and use of High Altitude Long Endurance (HALE) UAS since the 1990's. The NASA Environmental Research Aircraft Sensor and Technology Program (ERAST) demonstrated the promise of HALE aircraft for providing observations while also proving the importance of triple-redundant avionics to improve system reliability for large unmanned aircraft. Early efforts to develop an operational HALE capability for earth observations languished for nearly two decades owing to insufficient solar panel efficiency, battery power density, and light-weight, yet strong, materials. During this time NASA researchers focused on using the Global Hawk to demonstrate the utility of providing diurnal measurements over severe storms (i.e. HS3) and to track stratospheric water vapor transport (ATTREX). Recent significant commercial investments are now leading to the realization of a long-held goal of week- to month-long sustained observations and measurements from the stratosphere. In addition to a historical review of NASA use and interest in HALE aircraft, this paper will present current concepts for exploiting current and planned HALE aircraft capabilities including in situ characterization of atmospheric composition and dynamics as well as imagery collection and internet connectivity. NASA researchers anticipate HALE will also provide a useful means to test smallsat instruments and components. Observations from HALE-based instruments might also provide useful gap-filler observations to flagship satellite missions where the repeat time doesn't allow for measurements of quickly changing phenomenon. HALE will likely also provide measurements and communications relay to facilitate other aircraft in multi-aircraft campaigns. We will also report on progress towards a NASA-supported flight tests solar electric vehicles planned for 2019. One is the Swift Engineering UAS designed to carry 7kg (15lbs) for 30 days at 20km altitude. The other is the AeroVironment Hawk 30, also designed for multi-day flight.

Description: No abstract available

Description: Total ionizing dose (TID) and single-event effect (SEE) room-temperature radiation test results are presented for developmental prototype 4H-SiC junction field effect transistor (JFET) semiconductor integrated circuits (ICs) that have demonstrated prolonged operation in extremely high-temperature (500 C) environments. The devices tested demonstrated over 7 Mrad(Si) TID tolerance and no destructive SEE susceptibility.

Description: Total ionizing dose, displacement damage dose, and single-event effect testing were performed to characterize and determine the suitability of candidate electronics for NASA space utilization. Devices tested include optoelectronics, digital, analog, bipolar devices, and FPGAs.

Description: Total ionizing dose, displacement damage dose, and single-event effect testing were performed to characterize and determine the suitability of candidate electronics for NASA space utilization. Devices tested include optoelectronics, digital, analog, bipolar devices, and FPGAs.

Description: No abstract available

Description: Single-Event Effects (SEE) testing was conducted on the nVidia Jetson TX2 System on Chip (SOC). Testing was conducted at Massachusetts General Hospital's (MGH) Francis H. Burr Proton Therapy Center on June 2nd, 2019.

Description: Microprocessor, Graphics Processing Units (GPUs) and DDRx memory devices have emerged as promising next-generation technologies that enables both high performance processing and acceleration of complex algorithms for the latest challenges in human spaceflight, autonomous vehicles and artificial intelligence (AI). The feature sets of these devices offer exponential increases to throughput, calculation capability and system autonomy when compared to legacy flight systems. NASA's Electronic Part and Packaging (NEPP) Program has conducted an investigation into the radiation susceptibility of leading edge devices and process technologies by establishing standardized test approaches. Unlike most discrete devices, these require state of the art test systems to induce specific hardware activity similar to application software, thus allowing the characterization of failure modes within the system. To best characterize the tested part, NEPP eliminates variables that may impact device performance under radiation. Simplification of remaining system-level variables leads to an improved understanding of complex computational devices and their intended applications. The failure modes and error signatures that are recorded during testing are used to determine radiation sensitivity of the semiconductor process and the microcode architecture of the design. This presentation will discuss the test methodology that NASA Electronic Parts and Packaging (NEPP) is working to establish for its microprocessor, GPU and DDRx memory test programs to provide guidance on these devices and their underlying technology, in regards to their potential usage in future space flight systems.

Description: Electromagnetic Compatibility (EMC) is essential to the success of any vehicle design that incorporates a complex assortment of electronic, electrical, and electromechanical systems and sub-systems that is expected to meet operational and performance requirements while exposed to a changing set of electromagnetic environments composed of both man-made and naturally occurring threats. The combined aspects of these environments are known as Electromagnetic Environmental Effects (E3). The attainment of EMC is accomplished through the application of sound engineering principles and practices that enable a complex vehicle or vehicles to operate successfully when exposed to the effects of its expected and/or specified electromagnetic environments.

Description: New manufacturing methods are needed to obtain innovative electric motor designs that have much higher power densities and/or efficiencies compared to the current state-of-the-art. Additive manufacturing offers the potential to radically change motor designs so that they have compact designs, multi-material components, innovative cooling, and optimally designed and manufactured components. New component designs enabled by additive manufacturing technologies have been designed and were fabricated to include the housing, rotors, stator cooling ring, a direct printed stator, and a wire embedded stator. The new components were integrated into the motor and tested evaluate the performance gains in comparison to the baseline electric motor configuration. Partners on the sub-project include NASA GRC, NASA LaRC, NASA AFRC, LaunchPoint Technologies, and the University of Texas El Paso.

Description: High precision attitude measurement systems obviate the need for the beacon from the receiver making it possible for the spacecraft to beam a laser communications signal to a ground station without the ground station advertising its location. The research presented targets new detection and estimation methods to improve the accuracy in locating stars on a focal plane detector, and an understanding of the effects of changes in the optics design parameters and aberration, including defocus, on the navigation solution itself. This understanding can lead to an optimization of the attitude solution with respect to those optics realm parameter changes. The methodology discussed includes the development of a model of a current star tracker system. Using this model, multiple algorithms are implemented, including a multi-hypothesis method (MHT), to detect and estimate the position of the stars on the focal plane detector. It will be shown that using the MHT for detection and estimation, a greater accuracy can be found for each star estimation from more traditional detection and estimation algorithms. The approach then uses the model to develop statistics of the star tracker and the attitude estimation outputs to understand the accuracy, or variance, of the system's attitude solution. This solution is repeated for a range of defocus aberration, and a lower limit to the variance of the attitude solution is shown. A Cramer Rao lower bound solution is derived for the star tracker system and the results are compared to the Monte Carlo analysis from the model and shown to correlate very well. The approach uses a star image not as a Gaussian spot on the focal plane as done in previous work, and use of an image that includes the effects of aberrations of the optic system, and the effects of under-sampling and noise from the focal plane detector as well. Analysis includes exploring a star tracker's accuracy improvement through the combination of focus error and under-sampling effects alone, possibly contradicting conventional wisdom and approaches.

Description: NASA Langley and Glenn Research Centers have collaborated on the usage of acoustic liners mounted very near or directly over the rotor of turbofan aircraft engines. This collaboration began over a decade ago with the investigation of a metallic foam liner. Similar to conventional acoustic liner applications, this liner was designed to absorb sound generated by the rotor-alone and rotor-stator interaction sources within the fan duct. Given its proximity to the rotor tips, the expectation was that the liner would also serve as a pressure release and thereby inhibit the amount of noise generated. Initial acoustic results were promising, but there was concern regarding potential aerodynamic penalties. Nevertheless, there were sufficient positive results to warrant further investigation. To that end, the current report presents results obtained in the NASA Langley Normal Incidence Tube for 20 acoustic liner candidates for the OTR application. The majority contain grooves at their surface, designed to minimize aerodynamic penalties caused by placing the liner in close proximity to the fan rotor tips. The intent is to assess the acoustic properties of each liner configuration, and in particular to assess the effects of including the grooves on the overall acoustic performance. An additional intent of this paper is to provide documentation regarding recent enhancements to the NASA Langley Normal Incidence Tube.

Description: A series of electromagnetic simulations was conducted for the Conformal Lightweight Antenna System for Aeronautical Communications Technologies (CLAS-ACT) Program. The program designed, built, and flight tested a 14.25 GHz conformal patch array antenna for satellite communications on a T-34C airplane. Various studies were performed to evaluate the effects of antenna element spacing, array shape, signal taper, phased array pointing angle, null steering coefficients, antenna platform, and location on the airplane. This report documents the methods and some of the results of tests done over a 2 year period.

Description: Single-event effects and total ionizing dose testing is described for a 32-layer NAND flash memory, in both SLC and MLC configurations, with special considerations for unique three-dimensional test results.

Description: A streamlined Multi-Disciplinary Analysis and Optimization (MDAO) process is being developed to provide feedback on conceptual designs and early airspace modeling assessments of unconventional aircraft. This MDAO process has been demonstrated using a Low-Boom Flight Demonstrator (LBFD) like configuration by performing a trade study of various flap sizes. The results of this trade showed that shorter takeoff distances are achieved with increased flap chord and flap deflections. This trend is unlike conventional transport type aircraft which typically show increased required takeoff distances due to the increased drag during its take-off flap configurations. The LBFD like configuration results are attributed to its high engine thrust which overcomes the higher drag associated with these takeoff flap configurations.

Description: NASAs Hypersonic Inflatable Aerodynamic Decelerator (HIAD) technology was selected for a Technology Demonstration Mission under the Space Technology Mission Directorate in 2017. HIAD is an enabling technology that can facilitate atmospheric entry of heavy payloads to planets such as Earth and Mars using a deployable aeroshell. The deployable nature of the HIAD technology allows it to avoid the size constraints imposed on current rigid aeroshell entry systems. This enables use of larger aeroshells resulting in increased entry system performance (e.g. higher pay-load mass and/or volume, higher landing altitude at Mars). The Low Earth Orbit Flight Test of an Inflatable Decelerator (LOFTID) is currently scheduled for late-2021. LOFTID will be launched out of Vandenberg Air Force Base as a secondary payload on an Atlas V rocket. The flight test features a 6m diameter, 70-deg sphere-cone aeroshell and will provide invaluable high-energy orbital re-entry flight data. This data will be essential in supporting the HIAD team to mature the technology to diameters of 10m and greater. Aeroshells of this scale are applicable to potential near-term commercial applications and future NASA missions. Currently the LOFTID project has completed fabrication of the engineering design unit (EDU) inflatable structure (IS) and the flexible thermal protection system (F-TPS). These two components along with the rigid nose and center body comprise the HIAD aeroshell system. This EDU aeroshell is the precursor to the LOFTID aeroshell that will be used for flight. The EDU was built to verify the design given the subtle differences between the LOFTID aeroshell and past aeroshell designs that have been fabricated under the NASA HIAD project. To characterize the structural performance of the LOFTID aeroshell design, three structural tests will be performed. The first test to be conducted is static load testing, which will induce a uniform load across the forward surface of the aeroshell to simulate the expected pressure forces during atmospheric entry. The IS integrated with the rigid center body will first be tested alone to provide data for analytical model correlation, and then the F-TPS will be integrated for a second series of static load testing of the full aeroshell system. Instrumentation will be employed during the test series to measure component loads during testing, and a laser scanner will be used to generate a 3D map of the aeroshell surface to verify that the shape of the structure is acceptable at the simulated flight loads. After static load testing, pack and deployment testing will be conducted multiple times on the integrated system to demonstrate the aeroshells ability to fit within the required packed volume for the LOFTID mission without experiencing significant damage. Finally, the aeroshell will undergo modal testing to characterize its structural response. This presentation will discuss the setup and execution of each of the three tests that the EDU aeroshell will undergo. In addition, initial results of the testing will be presented outlining key findings as LOFTID moves for-ward with fabrication of the flight aeroshell.

Description: Technology is changing at a fast pace. Transistor geometries are getting smaller, voltage thresholds are getting lower, design complexity is exponentially increasing, and user options are expanding. Consequently, reliable insertion of error detection and correction (EDAC) circuitry has become relatively challenging. As a response, a variety of mitigation techniques are being evaluated. They range from weak EDAC circuits that save area and power to strong mitigation strategies that are a great expense to systems. This presentation will focus on radiation induced susceptibilities for a variety of FPGA types and ASIC devices. In addition, the user will be provided information on applicable mitigation strategies per device.

Description: Electrical power and control systems designed for use in planetary exploration missions and deep space probes require electronics that are capable of efficient and reliable operation under extreme temperature conditions. In addition, space-based infrared satellites, all-electric ships, jet engines, electromagnetic launchers, magnetic levitation transport systems, and power facilities are also typical examples where system electronics are expected to be exposed to harsh temperatures and to operate under severe thermal swings. Most commercial-off-the-shelf (COTS) devices are not designed to function under such extreme conditions and very little data exist on their performance outside their specified range of operation. In this work, the performance of an ultrafast gate driver for controlling power-level transistors was evaluated under extreme temperatures and thermal cycling. The investigations were carried out to assess performance for potential use of this device in space exploration missions under extreme temperature conditions.

Description: Heat flux characterization of high-enthalpy boundary layer flows is key to optimize the performance and design of Thermal Protection System of next generation aerospace vehicles [1]. At atmospheric entry hypersonic speeds, ablation as well as surface catalycity impact boundary layer aeroheating. Out-gassing occurring from an ablative surface in planetary entry environment introduces a rich set of problems in thermodynamic, fluid dynamic, and material pyrolysis. Ablation leads to out-gassing and surface roughness, both of which are known to affect surface heating in hypersonic chemically reacting boundary layers via three main routes: gas blowing into the boundary layer from the wall, changing the surface heat transfer due to wall-flow chemical reactions, and modifying surface roughness via ablative processes.

Description: Innovative technology has to prove itself in the context of legacy regulations. The knowledgeable technologist must engage standards process and regulating authorities to understand their roles and to advise the effect of new technology, and with manufacturers to demonstrate technology benefit. A model for Innovative Technology Environment relating NASA to industry, standards and regulation is described. The needs of the standards community of the X-57 are identified, and a NASA standards structure is described. No NASA project works with standards and regulatory organizations like the X-57.

Description: This report describes a generic method for addressing any new technology to its associated set of regulations and certification criteria. The result is a framework under which a detailed assessment can be conducted. Using just such a framework, the report maps the detailed updated regulations and evolving ASTM standards to the particular technology planning and tests. As a result, a roadmap of NASA technology is documented that shows clear transfer of technology data to industry (standards developers, as well as technology developers) and the FAA regulatory policy and certification staff upon whom certification and policy will be data-driven. A clear description of benefits and gaps are identified, as well.

Description: The main goal of this project is to fulfill the need of a controller upgrade for the Cavity Environmental Control System (CECS) on the NASA SOFIA aircraft. The preceding controller had multiple disadvantages including operating in an unpressurized region, incomplete functionality implementation, limited fault and status monitoring capability, and reduced maintainability and reliability. The new controller will go through the NASA design process to fulfill all the requirements of CECS operation including complete functionality of all devices currently installed on the aircraft, added devices to improve fault and health monitoring, and overall improvement in maintainability and reliability.

Description: The analytical model for the device drain-source turn-on overvoltage in three-level active neutral point clamped (3L-ANPC) converters is established in this paper. Considering the two commutation loops in the converter, the relationship between the overvoltage and the loop inductances is evaluated. The line switching frequency device usually exhibits higher overvoltage, while the high switching frequency device is not strongly influenced by the multiple loops. A 500 kVA 3L-ANPC converter using SiC MOSFETs is tested, and the model is verified with the experimental results.

Description: We have performed the initial characterization of single crystal 4H silicon carbide (4H-SiC) pressure sensors to determine the operational reliability over time at 800 C. Important parameters such as the zero pressure offset, bridge resistance, and pressure sensitivity as they are affected by temperature were extracted. These parameters showed relative stability within the prescribed operational envelop of the sensor at 800 C. Of significance is the increase in pressure sensitivity with increasing temperature beyond 400 C, to the extent that the sensitivity at 800 C was higher than the room temperature value. The implication of this result is that the sensor can be inserted further into the high temperature environment, thereby capturing the wider bandwidth of the pressure transients than currently possible.

Description: Wing design optimization has been studied extensively and is of continued interest as optimization tools are developed and become more accessible. In each of these studies, certain assumptions and simplifications are made to make the design problem tractable. However, it is difficult to find systematic studies in which several considerations are added or removed one at a time to study how much impact they have. In this work, we examine how certain physical considerations (viscous drag, wave drag, thrust loads, and inertial relief from structural, fuel, and engine masses), impact the aerostructural optimization results for three distinct aircraft wings. The goal is to help develop a rough idea of how important these physical considerations are. We do this using gradient-based optimization and a multidisciplinary design optimization framework, OpenMDAO. We use the open-source tool OpenAeroStruct that couples a vortex lattice method to a finite element method. We establish a baseline aerostructural design optimization problem then perform a series of optimizations, each with one physical consideration removed from the baseline case. We find that depending on the size of the aircraft and flight conditions, the importance of some of these physical considerations varies considerably whereas the importance of others do not. Specifically, the optimal designs change radically without proper viscous and wave drag considerations and smaller aircraft with more distributed propulsion are more affected by the inclusion of engine loads.

Description: The accurate prediction of turbulent mixing in high-pressure turbines that incorporate various airfoil surface-cooling strategies is becoming increasing critical to the design of modern gas turbine engines where the quest for improved efficiency is driving compressor overall pressure ratios and turbine inlet temperatures to much higher levels than ever before. In the present paper, a recently developed computational capability for accurate and efficient scaleresolving simulations of turbomachinery is extended to study the turbulent mixing mechanism of a simplified abstraction of an airfoil trailing-edge cooling slot - a plane wall jet with finite lip thickness discharging into an ambient flow. The computational capability is based on an entropy stable, discontinuousGalerkin approach that extends to arbitrarily high orders of spatial and temporal accuracy. The numerical results show that the present simulations capture the trends observed in the experiments. Discrepancies between the simulations and experiments are believed to be due to differences in the inflow profiles and tunnel sidewall effects. The thick lip configuration leads to a thicker wake and higher unsteadiness in the wall jet compared to the thin lip. A detailed comparison of the turbulent flowfields is presented to highlight differences arising due to lip thickness variations.

Description: Mission success criteria at the device level and required device operation/availability can determine the risk posed by the radiation effects for a given device in a given environment, but rarely are the same from one mission to another. A large portion of New Space / SmallSat missions to date have benefitted from relatively short mission durations and chosen orbits that have less severe particle populations than their larger counterparts. As mission objectives grow and become reliant on their chosen devices operating for longer lives and in more harsh environments, requirements need to reflect the changing scope but not hinder design adoptions from previously successful missions that provide new capabilities. This presentation describes notable differences in radiation environments, the requirement changes that come with choice of orbit, and prioritizations for mission success criteria to be determined by the designers of the system and subsystems. Test methodologies based on radiation effect categories are explained briefly; when they are needed. Similarity data (and its limitations) are discussed so that caveats and short-comings are understood. Reliability and assurance quantification may not always be possible, but determining where risks are taken and how to classify them is the essential topic for the intended practice: to establish radiation requirements with the goal of getting to mission success.

Description: NASA Glenn Research Center has been pursuing the development of dynamic power conversion for several decades. Candidate NASA missions involve mutli-year travel to far away destinations, or to extreme environments where sunlight does not exist. Human-base mission studies also show that power needs would be beyond the capabilities of solar energy conversion, and instead would require nuclear reactor energy sources, for which the thermal energy must be converted to electricity. Dynamic power conversion technology has developed sufficiently to make a sound engineering argument that it is suitable for these NASA missions. Dynamic conversion power sources have yet to be flown in space, and thus suffer a disadvantage owing to their lack of heritage data on flight missions. One of the largest obstacles for adoption is the uncertainty in reliability of a device with moving parts. However, significant progress has been made toward demonstrating the technology capable in all relevant environments, with the necessary long life. Another hurdle for adoption is the lack of mission, which would drive specific requirements, and provide a solid timeline for technology development endpoint. Until a mission is identified, an alternative approach is necessary to advance a dynamic power conversion system towards flight.

Description: The Tiltrotor Test Rig (TTR) was tested in the National Full-Scale Aerodynamics Complex (NFAC) 40- by 80-Foot Wind Tunnel from 2017 to 2018. The rotor system can be configured in airplane mode, with the rotor plane perpendicular to the wind flow, and in helicopter mode, with the rotor plane parallel to the wind flow. Four microphones were placed around the TTR: two on the wind tunnel floor and two on struts. The primary goal of the test was to understand the operational capabilities of the TTR, while also acquiring research data as available. Limited measurements of the blade vortex interaction (BVI) noise of the TTR rotor were taken to not only understand the acoustic testing capabilities of the TTR in the NFAC 40- by 80-Foot Wind Tunnel, but to also compare to previous tests and to be used for future validation studies. In particular, data will be compared to measurements of an XV-15 rotor previously acquired in the NFAC 80- by 120-Foot Wind Tunnel.

Description: No abstract available

Description: There are several mechanisms which have been proposed for the existence of colossal dielectric constant in the class of perovskite calcium copper titanate (CaCu3Ti4O12 or CCTO) materials. Researches indicate that existence of twinning parallel to (100) (001) and (010) planes causes planar defects and causes changes in local electronic structure. This change can cause insulating barriers locally which contribute to the large dielectric values irrespective of processing. The combination of insulating barriers, defects and displacements caused by twinning have been attributed to the generation of large dielectric constant in CCTO. To examine some of these arguments some researchers replaced Ca with other elements and evaluated this concept. In this study we present the synthesis and characterization of Ga2/3Cu3Ti4O12-xNx (GCTON) material. This provides both distortion due to atomic size difference and defects due to insertion of nitrogen. The morphology of the compound was determined to show that processing has tremendous effect on the dielectric values. The resistivity of GCTON was several order higher than CCTO and dielectric constant was higher than 10,000.

Description: No abstract available

Description: The overall goal of this research project is to improve the response and sensitivity of the AC Retarding Potential Analyzer (RPA). The AC RPA can accurately measure the flux, energy, and energy distribution of charged particles in a space environment. The enhancement of the sensor derives from changes that increase sensitivity of flux measurements through reduction of the baseline noise. The enhanced AC RPA sensor allows diagnosis of required charge particle beams necessary for tests of materials, instruments and subsystems, for future exploration missions.

Description: Overview of agency-level electronic parts management, the NASA Electronic Parts and Packaging (NEPP) Program, and NEPP Program Fiscal Year 2019 task investment areas.

Description: Supersonic aircraft are challenging to optimally design due to the widely varying constraints and flight conditions they experience. Additionally, a large number of disciplinary subsystems must be considered due to highly complex design requirements. One subsystem that has a major effect on overall performance is the engine. In this work, we construct a supersonic mixed-flow variable cycle engine and perform multipoint gradient-based optimization using this model. We see that the operational variables allow the optimizer to tailor performance at each individual flight condition, leading to better overall performance. To simulate airframe integration constraints, we run successive optimizations with increasingly restrictive inlet areas and see decreases in engine performance. This work is part of a larger effort to incorporate engine design into aero-thermal-mission optimization of a supersonic aircraft.

Description: Many of the aircraft concepts of the future are exploring the use of hybrid-, turbo- or all-electric propulsion systems to improve performance and decrease environmental impacts. These aircraft concepts range from small rotorcraft for urban air mobility to conventional commercial transports to large blended wing body designs. Developing the conceptual design for these vehicles presents a challenge, however, as traditional aircraft design tools often were not developed to handle these unique propulsion system architectures. Previous studies on these vehicles have therefore relied on relatively simple models of the electrical transmission and distribution system. This paper presents the development of a hybrid AC-DC load flow (or power flow) analysis capability to enhance the conceptual design of these concept vehicles. Specifically, the desire was to create a load flow analysis capability within the OpenMDAO framework that is also being used to develop a set of compatible tools for rapid optimization of conceptual designs. This load flow analysis capability is unique in its flexible object-oriented structure and implementation of analytic derivatives to facilitate the use of solvers and gradient based optimization in the design process. The developed hybrid load flow analysis capability is first verified against a published 13-bus example then used to model the electrical distribution system for a turbo-electric tiltwing aircraft.

Description: Urban Air Mobility vehicles are intended to operate near or within large cities, where a significant portion of the public will be exposed to the noise they create. If these vehicles are to become acceptable to the public, designers must be able to manage the amount of noise they generate, and understand the relationship between traditional performance metrics (thrust, efficiency, etc.) and noise. As a first step to addressing this need, this work combines a blade element momentum theory tool (OpenBEMT) with an acoustic prediction tool (ANOPP2) to optimize a propeller subject to both aerodynamic and acoustic constraints. These tools are developed within a optimization framework (OpenMDAO) that allows analytic derivatives to be propagated through the models and passed to a gradient-based optimizer. This tool chain is exercised on the cruise propellers from the X-57 Maxwell, and yields propeller designs that reduced the overall sound pressure level by about 5 dB for a cost of 1% propeller efficiency.

Description: No abstract available

Description: In the 47 years since single-event effects were first observed in spacecraft electronics, radiation experts have developed an effective methodology supported by a nationwide infrastructure. A highly skilled workforce of radiation engineers has developed test facilities and methods, modeling and simulation techniques, and mitigation and design strategies to ensure space missions meet their performance and reliability requirements even in the harsh radiation environments of space. Now, increasing performance demands of space missions, the continued disruptive evolution of microcircuit technologies and growth and changes of the space industry have combined with an aging infrastructure are placing increasing strain on the radiation effects community, and the community is responding.

Description: No abstract available

Description: This paper introduces the new Portable Laser Guided Robotic antenna range (PLGR) at the National Aeronautics and Space Administration's (NASA) Glenn Research Center. Previous work used industrial robots in fixed facilities to characterize antennas and required fixtures that do not lend themselves to portable applications.NASA's PLGR system is designed for in-situ antenna measurements at a remote site. The system consists of a robot arm mounted on a vertical lift and a laser tracker, each on a portable base. The lift and laser tracker enable scanning a surface larger than the robot's reach. To accomplish this the robot first collects all points within its reach, then the system is moved and the laser tracker is used to relocate the robot before additional points are captured.The PLGR architecture will be discussed including how safety systems and path planning are combined to effectively characterize antennas. Software was written in high level languages for flexible integration of vector network analyzers and antenna controllers. Lastly, data will be shown to demonstrate the system functionality and accuracy.

Description: Single-Event Effects (SEE) testing was conducted on the AMD e9173 Graphics Processor Unit (GPU). Testing was conducted at Massachusetts General Hospital's (MGH) Francis H. Burr Proton Therapy Center.

Description: Single-Event Effects (SEE) testing was conducted on the AMD Ryzen 3 2200G microprocessor with integrated graphics. Testing was conducted at Massachusetts General Hospital's (MGH) Francis H. Burr Proton Therapy Center on June 2nd, 2019.

Description: Single-Event Effects (SEE) testing was conducted on the AMD Ryzen 3 1200 microprocessor. Testing was conducted at Massachusetts General Hospital's (MGH) Francis H. Burr Proton Therapy Center on June 2nd, 2019.

Description: The present paper details the design of the counter rotating fans for a Turboelectric Distributed Propulsion (TeDP) system. Sixteen propulsors installed in mail-slot-shape nacelles are embedded on an aerodynamically optimized hybrid wing-body configuration. The hybrid-wing/body (HWB) configuration which was previously designed to satisfy the conditions of trim, longitudinally static stability and specific cargo space is employed as the baseline configuration in pursuing an optimal distributed propulsion system. A set of distributed propulsors is conceptually designed and the collective performance is evaluated against the target thrust mandated by the mission requirements. The concept of the distributed propulsion allows the fan pressure ratio to be around 1.27~1.32 for the target thrust. In addition, further splitting of the fan pressure ratio by using the counter-rotating fans for each slot realizes the target pressure ratio with low tip speed. In the distributed propulsion system, the nature of the flow conditions and/or the thickness of the ingested boundary layer may differ and result in different propulsive reaction of each individual propulsor. The optimization is, thus, approached from both the propulsion system and individual propulsor perspectives. An optimal distribution of the thrust and power output is determined by how the system utilizes each passage's propulsive characteristics and its interaction with the airframe. These system level analysis and optimization are conducted using an actuator disk model to account for the propulsion-airframe integration numerically. With respect to the propulsor level, aerodynamic shape optimizations of the fan blades are performed in a sequential multi-objective optimization process for various design objectives, such as mass flow rate condition, fan pressure ratio, efficiency and the exit flow angle of the fan stage by using a genetic algorithm, NSGA-II. The radial chord distribution, and meanline distribution of the rotors are designed on the circumferentially averaged axi-symmetric inlet profiles and tested on the six inlet profiles from six divided sectors to reckon flow distortion. The performances of the counter rotating fans are, thus, evaluated accordingly for obtaining distortion tolerant fan. The performance of the distributed propulsion system is evaluated by two CFD tools, i.e., a multi-stage turbo-machinery CFD code and one propulsion-airframe integration flow solver coupled with a body-force model. The optimized boundary layer ingestion propulsion system of 16 distributed slots not only reaches the system target thrust, but also delivers a close to 20% fuel saving benefit against its counterpart 12 distributed clean inlet propulsion system.

Description: Safe Unmanned Aerial Vehicle (UAV) operations near the ground require navigation methods that avoid fixed obstacles such as buildings, power lines and trees. Aerial lidar surveys of ground structures are available with the precision and accuracy to geolocate obstacles, but the high volume of raw survey data can exceed the compute power of onboard processors and the rendering ability of ground-based flight planning maps. Representing ground structures with bounding polyhedra instead of point clouds greatly reduces the data size and can enable effective obstacle avoidance, as long as the bounding geometry envelopes the structures with high spatial fidelity. This report describes in detail four methods to compute bounding geometries of ground obstacles from lidar point clouds. The four methods are: 1) 2.5D Maximum Elevation Box, 2) 2.5D Ground Map Extrusion, 3) 3D Bounding Cylinder, and 4) 3D Bounding Box. The methods are applied to five point cloud datasets from lidar surveys of UAV flight research sites in Georgia and Virginia with an average point spacing that ranges from 0.1m to 0.6m. The methods are assessed using survey areas with geometrically heterogeneous ground structures: buildings, vegetation, power lines, and sub-meter structures such as road signs and guy wires. The 2.5D Maximum Elevation Box method is useful for simple structures. The 2.5D Ground Map Extrusion method efficiently encloses vegetation, but requires handdrawn ground footprints. The 3D Bounding Cylinder method excels at enclosing linear structures such as power lines and fences. The 3D Bounding Box method excels at enclosing planar structures such as buildings. The methods are compared on the basis of data compression and boundary fidelity on selected areas. The 2.5D methods yield the highest data compression but the polyhedra produced by them enclose significant amounts of empty space. Boundary fidelity is superior for the 3D methods, though this fidelity comes at the cost of a roughly thirtyfold lower data compression ratio than the 2.5D Maximum Elevation Box method. A mix of these output geometries is proposed for autonomous UAV navigation with limited on-board computing. Both the accuracy and spatial detail of emerging satellite-based survey technology lower than that of aerial lidar scanning survey technology. Sub-meter structures and thin linear structures are not reliably mapped at present by satellite-based surveys.

Description: The Airborne Spacing for Terminal Arrival Routes (ASTAR) Flight Test was conducted by the NASA Air Traffic Management Technology Demonstration 1 (ATD- 1) project to demonstrate the use of NASAs ASTAR algorithm beyond a simulated environment and assess the operational risks of performing a multi-aircraft flight test of Flight-deck Interval Management (FIM). Utilizing contemporary tools of the Federal Aviation Administrations Next Generation Air Transportation System (NextGen) such as ADS-B, the ASTAR algorithm calculated speeds that the flight crew flew to achieve a precise spacing interval behind another aircraft at the final approach fix. Airspeed commands issued by the algorithm were flown by the flight crew of the FIM-equipped aircraft to achieve or maintain an assigned spacing goal from a target vehicle. The ASTAR algorithm was integrated with the Boeing supplied B-787 ecoDemonstrator aircraft, and five flight trials were conducted as a joint effort between NASA and Boeing on December 12, 2014. Initial results indicated arrival times within several seconds of accuracy of the planned termination point between two aircraft performing FIM in a real world environment. This flight test opened the way for the much more expansive ATD-1 Avionics Phase II flight test which occurred in early 2017. The flight trials under Phase II preceded further testing by the community in preparation for inclusion of the Interval Management concept as a part of the NextGen environment.

Description: Gallium nitride (GaN), a wide bandgap (WBG) semiconductor, has emerged as a very promising material for electronic components due to the tremendous advantages it offers compared to silicon (Si), such as power capability, extreme temperature tolerance, and high frequency operation. This presentation summarizes a body of knowledge (BOK) document in reference to the development and current status of GaN technology obtained via literature and industry surveys. It provides a listing of the major manufacturers and their capabilities, as well as government, industry, and academic parties interested in the technology. The presentation also discusses GaN's applications in the area of power electronics, in particular those geared for space missions. Finally, issues relevant to the reliability of GaN-based electronic parts are addressed and limitations affecting the full utilization of this technology are identified.

Description: These slides are an overview of the FT6 Test and Evaluation program.

Description: A tool to give the public a window into Unmanned Aerial Systems (UAS) Traffic Management (UTM) operations was created from an existing data collection tool. The interface included a map and a table showing details about UAS operations that could be queried in a number of ways. Eleven participants attended the study, successfully completing a 19-item task set in about 30 minutes. They correctly found information for 87% of the non-subjective tasks at a rate of around a minute per task, and rated the usability of the tool at the end of the session above the industry benchmark. Participants gave favorable reviews of the "public portal tool", even reporting that they would be satisfied with less information that it presented. There were one or two elements of the display that users found distracting and some navigation functions that need improvement, but on balance, the public representatives liked the features they saw in, and had few criticisms of, the public portal tool. One important issue for the small Unmanned Aerial System community to resolve will be how much or how little information should be available about UTM operations to members of the public.

Description: A tool to give the public a window into Unmanned Aerial Systems (UAS) Traffic Management (UTM) operations was created from an existing data collection tool. The interface included a map and a table showing details about UAS operations that could be queried in a number of ways. Eleven participants attended the study, successfully completing a 19-item task set in about 30 minutes. They correctly found information for 87% of the non-subjective tasks at a rate of around a minute per task, and rated the usability of the tool at the end of the session above the industry benchmark. Participants gave favorable reviews of the "public portal tool", even reporting that they would be satisfied with less information that it presented. There were one or two elements of the display that users found distracting and some navigation functions that need improvement, but on balance, the public representatives liked the features they saw in, and had few criticisms of, the public portal tool. One important issue for the small Unmanned Aerial System community to resolve will be how much or how little information should be available about UTM operations to members of the public.

Description: Overview of the projects in the Advanced Air Vehicle Program, Aeronautics Research Mission Directorate.

Description: No abstract available

Description: The paper describes a feedback controls design approach for a generic regional jet turbofan engine, which can be adapted to aero engines in general. To demonstrate this approach, linear models for control design are generated at different operating conditions from a full envelope nonlinear simulation created with the NASA Glenn Research Center-developed Toolbox for the Modeling and Analysis of Thermodynamic Systems. The primary objective is to design a single feedback controller that achieves good performance, without the need of developing scheduled control designs to cover the engine operating envelope. An additional objective is to progressively design more robust controllers that can perform under large variations in plant dynamics to also cover control for engine limits and potentially for some off nominal or even damaged conditions.

Description: This project intends to update and redesign imperfections in the scanned 3D CAD model of the Viking 400 aircraft. This aircraft, similar to the Sierra-B UAS, will carry payloads of scientific instruments for research purposes. The goals of this project are to modify the current scanned model such that it better represents the physical qualities of the aircraft, as well as creating the features that are missing from the model. As the model was imported from a different software, many of the critical surfaces did not accurately reflect the actual aircraft. Those parts of the model were redesigned entirely so that they can be edited for future use, as well as correctly representing the aircraft as it is now. Additionally, parts of the aircraft that did not appear in the scanned model were designed and added to the new model. In order to prioritize ease of use for future missions, the model has been reorganized in a logical fashion that enables modification of specific parts of the aircraft. The organization of this model imitates the drawing tree of the Sierra-B, with the intention of maintaining a functional system of redesign, analysis, and implementation. Ultimately, this project will be a catalyst for making Viking 400 into a functional aircraft and increasing scientific research in airborne vehicles.

Description: This presentation describes an Intern experience working with analog to digital converters.

Description: The Parallel Electric-Gas Architecture with Synergistic Utilization Scheme (PE- GASUS) vehicle is a regional aircraft concept that uses electric and hybrid-electric propulsors located strategically to obtain aerodynamic and mission benefits. Traditional aircraft analysis tools are not well suited to analyze the PEGASUS aircraft due to the different propulsor types used. This report summarizes a methodology that addresses some of the mission analysis challenges expected in modeling this vehicle concept. An initial baseline design is selected and sensitivity studies are performed to further understand the potential benefits of the concept.