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The Wide-Field Infrared Survey Telescope (WFIRST) mission, scheduled for a mid-2020's launch, is currently in its definition phase. The mission is designed to investigate essential questions in the areas of dark energy, exoplanets, and infrared astrophysics. WFIRST will use a 2.4-meter primary telescope (same size as the Hubble Space Telescope's primary mirror) and two instruments: the Wide Field Instrument (WFI) and the Coronagraph Instrument (CGI). In order to address the critical science...
Topics: 4a1f1a4803ee4b2ab4683db1216f6fb6, Greenbelt, MD, United States, Hsu, Oscar C., NASA Goddard Space...
The Wide-Field Infrared Survey Telescope (WFIRST) mission, scheduled for a mid-2020's launch, is currently in its definition phase. The mission is designed to investigate essential questions in the areas of dark energy, exoplanets, and infrared astrophysics. WFIRST will use a 2.4-meter primary telescope (same size as the Hubble Space Telescope's primary mirror) and two instruments: the Wide Field Instrument (WFI) and the Coronagraph Instrument (CGI). In order to ad-dress the critical science...
Topics: 7a6dcf9464b04698810d57776c40405b, Greenbelt, MD, United States, Hsu, Oscar, NASA Goddard Space...
A NATO symposium held in 2008 identified many promising sensitivity analysis and un-certainty quantification technologies, but the maturity and suitability of these methods for realistic applications was not known. The STO Task Group AVT-191 was established to evaluate the maturity and suitability of various sensitivity analysis and uncertainty quantification methods for application to realistic problems of interest to NATO. The program ran from 2011 to 2015, and the work was organized into...
Topics: 2b8c604b43674cfeb87ae8b1f8e3095b, Air Force Research Lab., Benek, John A., Luckring, James M., NASA...
A central element of air traffic management is the safe merging and spacing of aircraft during the terminal area flight phase. This paper derives and examines an algorithm for the merging and interval managing problem for Standard Terminal Arrival Routes. It describes a factor analysis for performance based on the distribution of arrivals, the operating period of the terminal, and the topology of the arrival routes; then presents results from a performance analysis and from a safety analysis...
Topics: NASA Langley Research Center, White, Allan L.
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An aeroelastic analysis of a prototype distributed electric propulsion wing is presented. Results using MSC Nastran (Registered Trademark) doublet lattice aerodynamics are compared to those based on FUN3D Reynolds Averaged Navier- Stokes aerodynamics. Four levels of grid refinement were examined for the FUN3D solutions and solutions were seen to be well converged. It was found that no oscillatory instability existed, only that of divergence, which occurred in the first bending mode at a dynamic...
Topics: 20da1b56e5df430ba312b7d9bb179e0f, 767955de6f3946dea8bca5a80582023f, Hampton, VA, United States,...
A NATO symposium held in Greece in 2008 identified many promising sensitivity analysis and uncertainty quantification technologies, but the maturity and suitability of these methods for realistic applications was not clear. The NATO Science and Technology Organization, Task Group AVT-191 was established to evaluate the maturity and suitability of various sensitivity analysis and uncertainty quantification methods for application to realistic vehicle development problems. The program ran from...
Topics: Air Force Research Lab., Benek, John A., Luckring, James M., NASA Langley Research Center,...
This paper evaluates the ability of progressive damage analysis (PDA) finite element (FE) models to predict transverse matrix cracks in unidirectional composites. The results of the analyses are compared to closed-form linear elastic fracture mechanics (LEFM) solutions. Matrix cracks in fiber-reinforced composite materials subjected to mode I and mode II loading are studied using continuum damage mechanics and zero-thickness cohesive zone modeling approaches. The FE models used in this study...
Topics: 2dd09c1279b74ca2850c92ee974dab80, 3694704c884d45c2b9cacf4f1fe7a160,...
Damage tolerant design approaches require determination of critical damage modes and flaw sizes in order to establish nondestructive evaluation detection requirements. A finite element model is developed to assess the effect of circular facesheet-core disbonds on the strength of sandwich specimens subjected to edgewise compressive loads for the purpose of predicting the critical flaw size for a variety of design parameters. Postbuckling analyses are conducted in which an initial imperfection is...
Topics: Bergan, Andrew C., NASA Langley Research Center
As a first step toward a study of acoustic disturbance field within a conventional, hypersonic wind tunnel, direct numerical simulations (DNS) of a Mach 6 turbulent boundary layer on the inner wall of a straight axisymmetric nozzle are conducted and the results are compared with those for a flat plate. The DNS results for a nozzle radius to boundary-layer thickness ratio of 5:5 show that the turbulence statistics of the nozzle-wall boundary layer are nearly unaffected by the transverse...
Topics: Choudhari, Meelan M., Duan, Lian, Huang, Junji, Missouri Univ. of Science and Technology, NASA...
This paper provides an overview of a research and development effort sponsored by the NASA Advanced Air Transport Technology Project to achieve the required high-lift performance using active flow control (AFC) on simple hinged flaps while reducing the cruise drag associated with the external mechanisms on slotted flaps of a generic modern transport aircraft. The removal of the external fairings for the Fowler flap mechanism could help to reduce drag by 3.3 counts. The main challenge is to...
Topics: 009d55dfafb84f14ae5d21e9559f8529, 1fa5b2b10130456289a8f55541029d7c,...
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Dec 23, 2021 NASA Technical Reports Server (NTRS)
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The primary objective of this work is to develop an approach for multifidelity uncertainty quantification and to lay the framework for future design under uncertainty efforts. In this study, multifidelity is used to describe both the fidelity of the modeling of the physical systems, as well as the difference in the uncertainty in each of the models. For computational efficiency, a multifidelity surrogate modeling approach based on non-intrusive polynomial chaos using the point-collocation...
Topics: 436f3f2012bf43a88fc668b738722a5e, Gumbert, Clyde, Hampton, VA, United States, NASA Langley Research...
The development of multidisciplinary integrated Structural Health Management (SHM) tools will enable accurate detection, and prognosis of damaged aircraft under normal and adverse conditions during flight. As part of the digital twin concept, methodologies are developed by using integrated multiphysics models, sensor information and input data from an in-service vehicle to mirror and predict the life of its corresponding physical twin. SHM tools are necessary for both damage diagnostics and...
Topics: 76b29c07285d493d80842bee6b74b898, Hampton, VA, United States, Krishnamurthy, Thiagarajan, NASA...
A status report is provided on the collaboration between the Royal Institute of Technology (KTH) in Sweden and the NASA Langley Research Center regarding the aeroelastic analyses of a full-span fighter configuration wind-tunnel model. This wind-tunnel model was tested in the Transonic Dynamics Tunnel (TDT) in the summer of 2016. Large amounts of data were acquired including steady/unsteady pressures, accelerations, strains, and measured dynamic deformations. The aeroelastic analyses presented...
Topics: 71f3bede25a14ccfaa2d28cbf3f21b7b, Chwalowski, Pawel, Eller, David, Hampton, VA, United States, NASA...
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NASA's investment and research in aviation has led to new technologies and concepts that make aircraft more efficient and environmentally friendly. One aircraft design operational concept is the reduction of cruise speed to reduce fuel burned during a mission. Although this is not a new idea, it was used by all of the contractors involved in a 2008 NASA sponsored study that solicited concept and technology ideas to reduce environmental impacts for future subsonic passenger transports. NASA is...
Topics: NASA Langley Research Center, Wells, Douglas P.
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Topics: 44ef311d18584b148d40dd3a3fbab98a, 5b65b365c135484b9279fae7e656f7e7, Alabama Univ., Colle, Brian,...
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Dec 23, 2021 NASA Technical Reports Server (NTRS)
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Requirements capture the system-level capabilities in a set of complete, necessary, clear, attainable, traceable, and verifiable statements of need. Requirements should not be unduly restrictive, but should set limits that eliminate items outside the boundaries drawn, encourage competition (or alternatives), and capture source and reason of requirement. If it is not needed by the customer, it is not a requirement. They establish the verification methods that will lead to product acceptance....
Topics: Bayt, Robert, NASA Johnson Space Center
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No abstract available
Topics: Groen, Frank, NASA Headquarters
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Dec 23, 2021 NASA Technical Reports Server (NTRS)
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The NASA Near Earth Network (NEN) consists of globally distributed tracking stations, including NASA, commercial, and partner ground stations, that are strategically located to maximize the coverage provided to a variety of orbital and suborbital missions, including those in LEO (Low Earth Orbit), GEO (Geosynchronous Earth Orbit), HEO (Highly Elliptical Orbit), lunar and L1-L2 orbits. The NEN's future mission set includes and will continue to include CubeSat missions. The first NEN-supported...
Topics: NASA Wallops Flight Facility, Schaire, Scott
An experimental study was conducted to measure the effects of long term hygrothermal aging on the impact penetration resistance of triaxially braided polymer composites. Flat panels of three different materials were subjected to repeated cycles of high and low temperature and high and low humidity for two years. Samples of the panels were periodically tested under impact loading during the two year time period. The purpose of the study was to identify and quantify any degradation in impact...
Topics: 2caad99289d9411b9c0c32a53a55ed5c, 51e7c63506fb4f5a99277adc0381408a,...
A CFD model for simulating the fluid dynamics of the jet induced mixing process is utilized in this paper to model the pressure control portion of the Tank Pressure Control Experiment (TPCE) in microgravity1. The Volume of Fluid (VOF) method is used for modeling the dynamics of the interface during mixing. The simulations were performed at a range of jet Weber numbers from non-penetrating to fully penetrating. Two different initial ullage positions were considered. The computational results for...
Topics: Apogee Engineering, LLC, Colorado Springs, CO, United States, Kartuzova, O., Kassemi, M., National...
NASA's Science Mission Directorate is sponsoring the development of a 4 kW-class Hall propulsion system for implementation in NASA science and exploration missions. The main components of the system include the High Voltage Hall Accelerator (HiVHAc), an engineering model power processing unit (PPU) developed by Colorado Power Electronics, and a xenon flow control module (XFCM) developed by VACCO Industries. NASA Glenn Research Center is performing integrated tests of the Hall thruster...
Topics: 64c5504c476b43efbc82a0d101c72178, 78cb9e3a37cd4638960dc676bd5584a5,...
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The Hall-Effect Rocket with Magnetic Shielding (HERMeS) thruster is being developed and tested at NASA GRC and NASA JPL through support of the Space Technology Mission Directorate (STMD) as primary propulsion for the Asteroid Redirect Robotic Mission (ARRM). This thruster is advancing the state-of-the-art of Hall-effect thrusters and is intended to serve as a precursor to higher power systems for human interplanetary exploration. A 2000-hour wear test has been initiated at NASA GRC with the...
Topics: 001d8b64ac604e39924b5de55a095bd1, 12f6248483aa434a84694c37df99a635,...
The life of Hall Effect thrusters are primarily limited by plasma erosion and thermal related failures. NASA Glenn Research Center (GRC) in cooperation with the Jet Propulsion Laboratory (JPL) have recently completed development of a Hall thruster with specific emphasis to mitigate these limitations. Extending the operational life of Hall thursters makes them more suitable for some of NASA's longer duration interplanetary missions. This paper documents the thermal model development, refinement...
Topics: 6dd0b7eb3bc6413c9e8f3cab75ef6d03, 7841a10f60eb4986a17b512c0a9fe5f3, Clayman, Lauren, Cleveland, OH...
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The Asteroid Redirect Robotic Mission is a Solar Electric Propulsion Technology Demonstration Mission (ARRM) whose main objectives are to develop and demonstrate a high-power solar electric propulsion capability for the Agency and return an asteroidal mass for rendezvous and characterization in a companion human-crewed mission. This high-power solar electric propulsion capability, or an extensible derivative of it, has been identified as a critical part of NASA'a future beyond-low-Earth-orbit,...
Topics: 0977e0fd1b044db8929a0ba25f03ab29, 70db61149786419eafb9e3982e185637,...
A computational investigation of a pressure-gain combustor system for gas turbine applications is presented. The system consists of a valved pulse combustor and an ejector, housed within a shroud. The study focuses on two enhancements to previous models, related to the valve and ejector components. First, a new poppet inlet valve system is investigated, replacing the previously used reed valve configuration. Secondly, a new computational approach to approximating the effects of choked turbine...
Topics: 46429643d1cd419f88afa79f4f45916c, 49f920fd902a47d2b254d4abab5bc455, Brook Park, OH, United States,...
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The NASA Hall Effect Rocket with Magnetic Shielding (HERMeS) 12.5 kW Technology Demonstration Unit-1 (TDU-1) Hall thruster has been the subject of extensive technology maturation in preparation for development into a flight ready propulsion system. Part of the technology maturation was to test the TDU-1 thruster in several ground based electrical configurations to assess the thruster robustness and suitability to successful in-space operation. The ground based electrical configuration testing...
Topics: 3cb506123a5549e38751d711cac301dd, 5caa80409ff44be9b1f25570def6e2a2,...
Lifetime requirements for electric propulsion devices, including Hall Effect thrusters, are continually increasing, driven in part by NASA's inclusion of this technology in it's exploration architecture. NASA will demonstrate high-power electric propulsion system on the Solar Electric Propulsion Technology Demonstration Mission (SEP TDM). The Asteroid Redirect Robotic mission is one candidate SEP TDM, which is projected to require tens of thousands of thruster life. As thruster life is...
Topics: 3f0c4b7c52fc4692ab47cae64042cd7b, 986df8a1b09c48049a265af385ba69cd, Brook Park, OH, United States,...
The NEXT Long-Duration Test is part of a comprehensive thruster service life assessment intended to demonstrate overall throughput capability, validate service life models, quantify wear rates as a function of time and operating condition, and identify any unknown life-limiting mechanisms. The test was voluntarily terminated in February 2014 after demonstrating 51,184 hours of high-voltage operation, 918 kg of propellant throughput, and 35.5 MN-s of total impulse. The post-test inspection of...
Topics: 47b52458a9124cb28c9dd998b105af25, Cleveland, OH United States, NASA Glenn Research Center, Shastry,...
The NEXT Long-Duration Test is part of a comprehensive thruster service life assessment intended to demonstrate overall throughput capability, validate service life models, quantify wear rates as a function of time and operating condition, and identify any unknown life-limiting mechanisms. The test was voluntarily terminated in February 2014 after demonstrating 51,184 hours of high-voltage operation, 918 kg of propellant throughput, and 35.5 MN-s of total impulse. The post-test inspection of...
Topics: 2f29296a7469469ca10e9acebe0bd3bd, Cleveland, OH United States, NASA Glenn Research Center, Shastry,...
An effort was undertaken to perform CFD analysis of fluid flow in Lean-Direct Injection (LDI) combustors with axial swirl-venturi elements for next-generation LDI-3 combustor design. The National Combustion Code (NCC) was used to perform non-reacting and two-phase reacting flow computations for a newly-designed pre-filming type fuel injector LDI-3 injector, in a single-injector and a five-injector array configuration. All computations were performed with a consistent approach of...
Topics: 0c2c942814554296869fb418a815f9d8, Ajmani, Kumud, Cleveland, OH, United States, Lee, Phil, Mongia,...
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A test to characterize the effect of varying background pressure on NASA's 12.5-kW Hall Effect Rocket with Magnetic Shielding had being completed. This thruster is the baseline propulsion system for the Solar Electric Propulsion Technology Demonstration Mission (SEP TDM). Potential differences in thruster performance and oscillation characteristics when in ground facilities versus on-orbit are considered a primary risk for the propulsion system of the Asteroid Redirect Robotic Mission, which is...
Topics: 16ac74b95d6c471a929cb71a189ca859, 9337b746f6684e7b8786d80d10cb0266, Cleveland, OH United States,...
A CFD model for simulating pressure control in cryogenic storage tanks through the injection of a subcooled liquid into the ullage is presented and applied to the 1g MHTB spray bar cooling experiments. An Eulerian-Lagrangian approach is utilized to track the spray droplets and capture the interaction between the discrete droplets and the continuous ullage phase. The spray model is coupled with the VOF model by performing particle tracking in the ullage, removing particles from the ullage when...
Topics: Apogee Engineering, LLC, Case Western Reserve Univ., Colorado Springs, CO, United States,...
A Long Duration Test (LDT) was initiated in June 2005 as a part of NASA's Evolutionary Xenon Thruster (NEXT) service life validation approach. Testing was voluntarily terminated in February 2014, with the thruster accumulating 51,184 hours of operation, processing 918 kg of xenon propellant, and delivering 35.5 MN-s of total impulse. The post-test inspection objectives for the ion optics were derived from the original NEXT LDT test objectives, such as service life model validation, and expanded...
Topics: Cleveland, OH United States, NASA Glenn Research Center, Shastry, Rohit, Soulas, George C.,...
As compared to driving on Earth, the presence of lower gravity and uneven terrain on planetary bodies makes high speed driving difficult. In order to maintain ground contact and control vehicles need to be designed with special attention to dynamic response. The challenge of maintaining control on the Moon was evident during high speed operations of the Lunar Roving Vehicle (LRV) on Apollo 16, as at one point all four tires were off the ground; this event has been referred to as the Lunar Grand...
Topics: 1c9dac883e3d45cd880f2676cac5a6ad, 60150ff5c1cf49b7a6fdebbf4cc90634, Asnani, Vivake, Cleveland, OH...
The Fission Surface Power (FSP) Technology Demonstration Unit (TDU) is a system-level demonstration of fission power technology intended for use on manned missions to Mars. The Baseline FSP systems consists of a 190 kWt UO2 fast-spectrum reactor cooled by a primary pumped liquid metal loop. This liquid metal loop transfers heat to two intermediate liquid metal loops designed to isolate fission products in the primary loop from the balance of plant. The intermediate liquid metal loops transfer...
Topics: 461d48c247944d05a8849fbcc48bf47e, Briggs, Maxwell H., Cleveland, OH United States, Geng, Steven,...
Vortex generators within a two-dimensional, external-compression supersonic inlet for Mach 1.6 were investigated to determine their ability to increase total pressure recovery, reduce total pressure distortion, and improve the boundary layer. The vortex generators studied included vanes and ramps. The geometric factors of the vortex generators studied included height, length, spacing, and positions upstream and downstream of the inlet terminal shock. The flow through the inlet was simulated...
Topics: 7aaefd283de441d8b2c6a26c30814c7b, 84edaa475e704e4996b66b07c28988e3, Arlington, TX, United States,...
The High Voltage Hall Accelerator (HiVHAc) propulsion system consists of a thruster, power processing unit (PPU), and propellant feed system. An engineering model PPU was developed by Colorado Power Electronics, Inc. funded by NASA's Small Business Innovative Research Program. This PPU uses an innovative 3-phase resonant converter to deliver 4 kW of discharge power over a wide range of input and output voltage conditions. The PPU includes a digital control interface unit that automatically...
Topics: 5abeda685c214b559c4afeca516fd670, 877a253fe4bd4a85abfd6ace73313158, Cleveland, OH United States,...
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Distributed engine control is a hardware technology that radically alters the architecture for aircraft engine control systems. Of its own accord, it does not change the function of control, rather it seeks to address the implementation issues for weight-constrained vehicles that can limit overall system performance and increase life-cycle cost. However, an inherent feature of this technology, digital communication networks, alters the flow of information between critical elements of the...
Topics: 0cf6cfb17c7e4b048afae1371e737ceb, Aretskin-Hariton, Eliot, Cleveland, OH United States, Cleveland,...
The primary goal of the Consortium for the Advancement of Shape Memory Alloy Research and Technology (CASMART) is to enable the design of revolutionary applications based on shape memory alloy (SMA) technology. In order to help realize this goal and reduce the development time and required experience for the fabrication of SMA actuation systems, several modeling tools have been developed for common actuator types and are discussed herein along with case studies, which highlight the capabilities...
Topics: 17ea55c3a62e4af7aab6fb30dd6a786b, 1d185e68d54a4f1e9e87914d42bc5730,...
A set of Laser Induced Fluorescence (LIF) measurements in the near-field region of the NASA- 173M Hall thruster plume is presented at four background pressure conditions varying from 9.4 x 10(exp -6) torr to 3.3 x 10(exp -5) torr. The xenon ion velocity distribution function was measured simultaneously along the axial and radial directions. An ultimate exhaust velocity of 19.6+/-0.25 km/s achieved at a distance of 20 mm was measured, and that value was not sensitive to pressure. On the other...
Topics: 474057105c42457a871c858ac8761cf3, Aerospace Corp., El Segundo, CA, United States, Kamhawi, H., NASA...
A pathfinder prototype unit and two flight power processing units (PPUs) are being developed by the Aerojet Rocketdyne Corporation in Redmond, Washington and ZIN Technologies in Cleveland, Ohio, in support of the NEXT-C Project. This project is being led by the NASA Glenn Research Center in Cleveland, Ohio, and will also yield two flight thrusters. This hardware is being considered to be provided as Government Furnished Equipment for the New Frontiers Program, and is applicable to a variety of...
Topics: 3745bd8873d54e8ab0e9f040a0144123, 3de4cf15e7814948a4b44bda428f7a7d,...
A calorimeter has been constructed to accurately measure insulation performance with a nominal 90K outer boundary and a 20K inner boundary. Unique features of this design include use of mechanical cryocoolers instead of cryogens and measurement of the heat load with a calibrated heat conduction rod. The calorimeter is operational and has completed its first test series. The initial test series was designed to look for differences in performance between a single layer of aluminum foil and a...
Topics: 11fe41dc90fb43948c9808e20fddabff, 38bc8a57a78243f0b88b385369da9af6,...
The essence of a distributed control system is the modular partitioning of control function across a hardware implementation. This type of control architecture requires embedding electronics in a multitude of control element nodes for the execution of those functions, and their integration as a unified system. As the field of distributed aeropropulsion control moves toward reality, questions about building and validating these systems remain. This paper focuses on the development of...
Topics: 56e7c32cf2074c17a506f0bfe6ac6956, Brand, Alex, Cleveland, OH United States, Cleveland, OH, United...
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This paper covers the application of a model-based engine control (MBEC) methodology featuring a self tuning on-board model for an aircraft turbofan engine simulation. The nonlinear engine model is capable of modeling realistic engine performance, allowing for a verification of the advanced control methodology over a wide range of operating points and life cycle conditions. The on-board model is a piece-wise linear model derived from the nonlinear engine model and updated using an optimal tuner...
Topics: Chicatelli, Amy, Cleveland, OH United States, Connolly, Joseph W., Csank, Jeffrey T., NASA Glenn...
WHAATRR gilder is a PRANDTL-M flying weather and space radiation sensor laden vehicle for identifying weather hazards for aviation safety.
Topics: 018a3580ac7c49e398027af1f5d4c91b, 0c271040d6f14c7d8c6c3a5fe2c7a9b3,...
This presentation gives insight into the research activities and efforts being executed in order to integrate unmanned aircraft systems into the national airspace system. This briefing is to inform others of the UAS-NAS FY16 progress and future directions.
Topics: 2cd0556f00f7415999805aef26ab6d25, Edwards, CA United States, Grindle, Laurie, Hackenberg, Davis,...
Canopy light interception is a main driver of water use and crop yield in almond and walnut production. Fractional green canopy cover (Fc) is a good indicator of light interception and can be estimated remotely from satellite using the normalized difference vegetation index (NDVI) data. Satellite-based Fc estimates could be used to inform crop evapotranspiration models, and hence support improvements in irrigation evaluation and management capabilities. Satellite estimates of Fc in almond and...
Topics: 393bbcfd58434558bc069a5e8915b107, 9827465d075a46b68c27a1607f777b4b, California State Univ. at...
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Dec 23, 2021 NASA Technical Reports Server (NTRS)
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The NASA Earth Exchange (NEX) is a collaborative computing platform that has been developed with the objective of bringing scientists together with the software tools, massive global datasets, and supercomputing resources necessary to accelerate research in Earth systems science and global change. NEX is funded as an enabling tool for sustaining the national climate assessment. Over the past five years, researchers have used the NEX platform and produced a number of data sets highly relevant to...
Topics: 072a1cc1a19f4d5599e8873a62df8008, 3f4e8908e86441809df0efdea7503208,...
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Aerosol types measured during the Ship-Aircraft Bio-Optical Research (SABOR) experiment are related to GEOS-Chem model chemical composition. The application for this procedure to link model chemical components to aerosol type is desirable for understanding aerosol evolution over time. The Mahalanobis distance (DM) statistic is used to cluster model groupings of five chemical components (organic carbon, black carbon, sea salt, dust and sulfate) in a way analogous to the methods used by Burton et...
Topics: 06f388b6674544b789ed446824513cec, 24375fba78a34601ab36b3adc24d7ba0,...
Ozone (O3) is a greenhouse gas and toxic pollutant which plays a major role in air quality. Typically, monitoring of surface air quality and O3 mixing ratios is primarily conducted using in situ measurement networks. This is partially due to high-quality information related to air quality being limited from space-borne platforms due to coarse spatial resolution, limited temporal frequency, and minimal sensitivity to lower tropospheric and surface-level O3. The Tropospheric Emissions: Monitoring...
Topics: 084b0d02970347b38301c7f65f4a110b, 31caed8531cd4e8081518f54ae5544b7,...
In the past decades, significant efforts have been made to increase tropospheric ozone long-term monitoring. A large number of ground-based, airborne and space-borne instruments are currently providing valuable data to contribute to better understand tropospheric ozone budget and variability. Nonetheless, most of these instruments provide in-situ surface and column-integrated data, whereas vertically resolved measurements are still scarce. Besides ozonesondes and aircraft, lidar measurements...
Topics: Affiliate (JPL), California Inst. of Tech., Granados Munoz, Maria Jose, Johnson, Matthew S.,...
Atmospheric mixing ratios of carbon dioxide (CO2) are largely controlled by anthropogenic emission sources and biospheric sources/sinks. Global biospheric fluxes of CO2 are controlled by complex processes facilitating the exchange of carbon between terrestrial ecosystems and the atmosphere. These processes which play a key role in these terrestrial ecosystem-atmosphere carbon exchanges are currently not fully understood, resulting in large uncertainties in the quantification of biospheric CO2...
Topics: 908b3c5a59f84a28b7c621536c2fcc3c, California State Univ. at Monterey Bay, Dalhousie Univ.,...
As aircraft wings become much more flexible due to the use of light-weight composites material, adverse aerodynamics at off-design performance can result from changes in wing shapes due to aeroelastic deflections. Increased drag, hence increased fuel burn, is a potential consequence. Without means for aeroelastic compensation, the benefit of weight reduction from the use of light-weight material could be offset by less optimal aerodynamic performance at off-design flight conditions. Performance...
Topics: 71bc31db795045109d59dfb3aa07a5d0, Chaparro, Daniel, Drew, Michael, Moffett Field, CA United States,...
In support of NASA's Commercial Supersonics Technology (CST) project, a test was conducted in the 9-by-7 ft. supersonic section of the NASA Ames Unitary Plan Wind Tunnel (UPWT). The tests were designed to study the interaction of shocks with a supersonic jet characteristic of those that may occur on a commercial supersonic aircraft. Multiple shock generating geometries were tested to examine the interaction dynamics as they pertain to sonic boom mitigation. An integral part of the analyses of...
Topics: 0c8c0d5b160e4f109104d4a819203135, 746d1126e4c0450b8ebe355bd02e3711, Durston, Donald A., Heineck,...
The NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP) dataset is comprised of downscaled climate projections that are derived from 21 General Circulation Model (GCM) runs conducted under the Coupled Model Intercomparison Project Phase 5 (CMIP5) and across two of the four greenhouse gas emissions scenarios (RCP4.5 and RCP8.5). Each of the climate projections includes daily maximum temperature, minimum temperature, and precipitation for the periods from 1950 through 2100 and the...
Topics: 2ece6cbf5cf1432dbc582df7be11fe8f, 58f521a7915440bc84b7b3e963d90685,...
High resolution tree cover classification maps are needed to increase the accuracy of current land ecosystem and climate model outputs. Limited studies are in place that demonstrates the state-of-the-art in deriving very high resolution (VHR) tree cover products. In addition, most methods heavily rely on commercial softwares that are difficult to scale given the region of study (e.g. continents to globe). Complexities in present approaches relate to (a) scalability of the algorithm, (b) large...
Topics: 6555a5491c084cf48b614f93cf4c15e2, 83ffdf58e3a7433da32645f0a328d376,...
Significant risks for visual impairment associated with increased intracranial pressure (VIIP) are incurred by microgravity spaceflight, especially long-duration missions [1]. We hypothesize that microgravity-induced fluid shifts result in pathological changes within blood vessels of the retina that precede development of visual and other ocular impairments. Potential contributions of retinal vascular remodeling to VIIP etiology are therefore being investigated for two studies in 30deg infrared...
Topics: 0b7433df3eeb496cbc807975665c6e9c, 27fcabc324ce4a4db3fe7f972addc05d,...
Predicting cancer risk associated with cosmic radiation remains a mission-critical challenge for NASA radiation health scientists and mission planners. Epidemiological data are lacking and risk methods do not take individual radiation sensitivity into account. In our approach we hypothesize that genetic factors strongly influence risk of cancer from space radiation and that biomarkers reflecting DNA damage and cell death are ideal tools to predict risk and monitor potential health effects...
Topics: 431a9ccd102343eead8223f741d1d3c1, Berkeley, CA, United States, California Univ., Lawrence Berkeley...
NASA Network Resource and Training Site
Dec 23, 2021 NASA Technical Reports Server (NTRS)
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No abstract available
Topics: Fikes, John C., NASA Marshall Space Flight Center
NASA Network Resource and Training Site
Dec 23, 2021 NASA Technical Reports Server (NTRS)
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The CTE (Composite Technology for Exploration) Project will develop and demonstrate critical composites technologies with a focus on joints that utilize NASA expertise and capabilities. The project will advance composite technologies providing lightweight structures to support future NASA exploration missions. The CTE project will demonstrate weight-saving, performance-enhancing bonded joint technology for Space Launch System (SLS)-scale composite hardware.
Topics: Fikes, John, NASA Marshall Space Flight Center
The United States Air Force's 45th Weather Squadron (45WS) is the organization responsible for monitoring atmospheric conditions at Cape Canaveral Air Force Station and NASA Kennedy Space Center (CCAFS/KSC) and issuing warnings for hazardous weather conditions when the need arises. One such warning is issued for convective wind events, for which lead times of 30 and 60 minutes are desired for events with peak wind gusts of 35 knots or greater (i.e., Threshold-1) and 50 knots or greater (i.e.,...
Topics: 1394ed5bf6e24761bd939efa43bde1e1, 2cc689045c44482885761b7447b35ae6,...
No abstract available
Topics: 68c8d1d73d5844ae88c32a7df9c26ac1, 9552206de471403d9f2e0ef6c2edb62a,...
The Cyclone Global Navigation OKLMA 1411 UTC Satellite System (CYGNSS) is a multi-satellite constellation that launched 15 December 2016. The primary objective of CYGNSS is to use bistatic Global Positioning System (GPS) reflectometry to accurately measure near-surface wind speeds within the heavily raining inner core of tropical cyclones. CYGNSS also features rapid revisit times over a given region in the tropics - ranging from several minutes to a few hours, depending on the constellation...
Topics: 3d57956b78374d9cae246b4cc315ba86, 58e6798dea0649cba1bbb7575dcda600, Alabama Univ., Castillo, Tyler,...
No abstract available
Topics: 0497e47322ac4393a763c042832f8323, 4dc2dfcc364f4ac382ac066b1dd06511,...
The Joint Polar Satellite System (JPSS) Program Office is the supporting organization for the Suomi National Polar Orbiting Partnership (S-NPP) and JPSS-1 satellites. S-NPP carries the following sensors: VIIRS, CrIS, ATMS, OMPS, and CERES with instruments that ultimately produce over 25 data products that cover the Earths weather, oceans, and atmosphere. A team of scientists and engineers from all over the United States document, monitor and fix errors in operational software code or...
Topics: ASRC Federal Space and Defense, Griffin, Ashley
NASA Network Resource and Training Site
Dec 23, 2021 NASA Technical Reports Server (NTRS)
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Informational slides to be shared with colleagues at the the European Space Agency (ESA).
Topics: Fatoyinbo, Temilola, 4b0f200df4f74b7db2516ca868a6dbdf, 6d82a3c66ab44e2cb1ecc7759ae97827, Bollian,...
An electrically conductive elastomer was evaluated as a material candidate for a spacecraft seal. The elastomer used electrically conductive constituents as a means to reduce the resistance between mating interfaces of a sealed joint to meet spacecraft electrical bonding requirements. The compound's outgassing levels were compared against published NASA requirements. The compound was formed into a hollow O-ring seal and its compression set was measured. The O-ring seal was placed into an...
Topics: 5f36181275d74647a4d4565f7f980ee6, 64aa581668224fa193ef9e908f410f7a,...
The development of ultra-efficient commercial vehicles and the transition to low-carbon emission propulsion are seen as thrust paths within NASA Aeronautics. A critical enabler to these paths comes in the form of hybrid-electric propulsion systems. For megawatt-class systems, the best power system topology for these hybrid-electric propulsion systems is debatable. Current proposals within NASA and the Aero community suggest using a combination of AC and DC for power transmission. This paper...
Topics: 5ef2e423567f4dacba9428f3a12b2277, 772383817c614e188e4afa1653a18364, Beach, Raymond F., Cleveland,...
Gas turbine compressor and turbine blade tip clearance (i.e., the radial distance between the blade tip of an axial compressor or turbine and the containment structure) is a major contributing factor to gas path sealing, and can significantly affect engine efficiency and operational temperature. This paper details the creation of a generic but realistic high pressure turbine tip clearance model that may be used to facilitate active tip clearance control system research. This model uses a first...
Topics: 0bf00b3c95e54ad2b931c6dc53fd48a8, 2054e4e39f744a65b2699f198d40b834, Brook Park, OH, United States,...
The performance of propulsion engine systems is sensitive to weight and volume considerations. This can severely constrain the configuration and complexity of the control system hardware. Distributed Engine Control technology is a response to these concerns by providing more flexibility in designing the control system, and by extension, more functionality leading to higher performing engine systems. Consequently, there can be a weight benefit to mounting modular electronic hardware on the...
Topics: 307a220b5af34a839adc85ebf7536e06, 56eed4b607ee4c82bf65311038351e87, Chapman, Jeffryes, Cleveland,...
The cost and risk associated with the design and operation of gas turbine engine systems has led to an increasing dependence on mathematical models. In this paper, the fundamentals of engine simulation will be reviewed, an example performance analysis will be performed, and relationships useful for engine control system development will be highlighted. The focus will be on thermodynamic modeling utilizing techniques common in industry, such as: the Brayton cycle, component performance maps, map...
Topics: 10b369c445bf4f0398be5785c58fe92c, Chapman, Jeffryes W., Cleveland, OH United States, Cleveland, OH,...
This paper presents results from tests in a flame tube facility, where a bio-derived alternate fuel was compared with JP-8 for emissions and general combustion performance. A research version of General Electric Aviation (GE) TAPS injector was used for the tests. Results include combustion efficiency from gaseous emission measurements, 2D planar laser-based imaging as well as basic flow visualization of the flame. Four inlet test conditions were selected that simulate various engine power...
Topics: 3b3a54586af540489b8894b376113d1f, Anderson, Robert C., Cleveland, OH United States, Hicks, Yolanda...
The conceptual design of a parallel gas-electric hybrid propulsion system for a conventional single aisle twin engine tube and wing vehicle has been developed. The study baseline vehicle and engine technology are discussed, followed by results of the hybrid propulsion system sizing and performance analysis. The weights analysis for the electric energy storage & conversion system and thermal management system is described. Finally, the potential system benefits are assessed.
Topics: 4e1d79b4c8d3471ea962d28a53a0e20c, 53f8ab2a4054457289ceb61c4e9f60e2, East Hartford, CT, United...
NASA Network Resource and Training Site
Dec 23, 2021 NASA Technical Reports Server (NTRS)
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ISRU involves any hardware or operation that harnesses and utilizes in-situ resources (natural and discarded) to create products and services for robotic and human exploration: Assessment of physical, mineral chemical, and volatile water resources, terrain, geology, and environment (orbital and local). Production of replacement parts, complex products, machines, and integrated systems from feedstock derived from one or more processed resources. Civil engineering, infrastructure emplacement, and...
Topics: 90fbf0b4a8a8425c9337598fc3e03eaf, Cleveland, OH United States, Cocoa Beach, FL, United States,...
Stirling Radioisotope Power Systems (RPS) are being developed as an option to provide power on future space science missions where robotic spacecraft will orbit, flyby, land or rove. A Stirling Radioisotope Generator (SRG) could offer space missions a more efficient power system that uses one fourth of the nuclear fuel and decreases the thermal footprint of the current state of the art. The RPS Program Office, working in collaboration with the U.S. Department of Energy (DOE), manages projects...
Topics: 6a72dc929bae4b148474a7bc00c4b8a6, Avon, OH, United States, Brook Park, OH, United States,...