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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,315 records · Page 73
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Hydrologic land use classification of the Patuxent River watershed using remotely sensed data

The Patuxent River Watershed is located in central Maryland between Baltimore and Washington, D.C. and is approximately 2330 sq km in area and 175 km long. This region is now at a critical point because of major concerns such as water management and quality, flooding and land use within the watershed. Data from the NASA-directed LANDSAT and Earth Resources Aircraft Programs were used to provide a new dimension in information collection and processing for the management of watersheds. Digital data from LANDSAT-1 were analyzed along with selected IR photography from U-2 flight number 74-060B taken 28 April 1974, which was digitized in three channels. Processing of the data was accomplished using a multispectral analysis system. Land use themes consisting of surface water, wetlands, forest, residential, cropland/pasture, urban, and extractive were developed and delineated through the watershed. Area measurements of watershed themes were obtained and will serve as a calibration input to a deterministic hydrologic model on a sub-watershed. Using the derived residential and urban theme areas from LANDSAT an estimated basin imperviousness was also calculated. Thematic maps were produced at 1:62,500 scale. Floodprone areas were also classified and delineated at a scale of 1:24,000. Comparison with standard floodprone area maps at the same scale have indicated a few areas of discrepancy. Such information can be used for updating or checking floodprone area boundaries as well as monitoring changes in floodplain areas.

Dallam, W. C.↗
NASA NTRS1977

The preliminary design of a lift-cruise fan airplane flight control system

This paper presents the preliminary design of a stability augmentation system for a NASA V/STOL research and technology airplane. This stability augmentation system is postulated as the simplest system that meets handling-quality levels for research and technology missions flown by NASA test pilots. The airplane studied in this report is a modified T-39 fitted with tilting lift/cruise fan nacelles and a nose fan. The propulsion system features a shaft that interconnects three variable-pitch fans and three powerplants. The mathematical modeling is based on pre-wind tunnel test estimated data. The selected stability augmentation system uses variable gains scheduled with airspeed. Failure analysis of the system illustrates the benign effect of engine failure. Airplane rate sensor failure must be solved with redundancy.

Gotlieb, P.↗
NASA NTRS1983

Investigation of radiometric properties of LANDSAT-4 MSS

Two full frames of radiometrically corrected (Type A) LANDSAT-4 MSS data were analyzed digitally and visually for evidence of residual calibration differences between detectors, quantization effects, and other sensor-related artifacts. Both standard statistical and Fourier analysis techniques were employed. Opportunities for coincident coverage by LANDSATS 3 and 4 were identified in the contiguous 48 states. Paired acquisitions for two scenes were obtained and analyzed to establish relationships between signal values from common areas imaged by the two MSS Systems. Initial findings on detector-to-detector differences, coherent noise, and LANDSAT 4 to LANDSAT 3 calibration are summarized. Results show that LANDSAT 4 MSS produces data of generally good quality with dynamic ranges and target responses similar to those of previous sensors.

Rice, D. P.↗
NASA NTRS1999

Global Observation of Planetary-Scale Waves in UARS HRDI and WINDII MLT Winds

The purpose of this study is to use examine planetary-scale motions in the UARS mesosphere and lower thermospheric data. The actual study was confined to HRDI winds and temperatures, since these observations were more continuous, and spanned the 60-120 km range. Three classes of waves were studied: fast equatorial Kelvin waves, nonmigrating tides, and the midlatitude 2-day wave. The purpose of the Kelvin wave and the 2-day wave studies was to test whether the waves significantly affect the mean flow. Such studies require high-quality spectral definitions in order to derive the wave heat and momentum flux divergence which can act in comination to drive the mean flow. Accordingly, HRDI winds from several special observing campaigns were used for analyses of fast (periods under 5 days) waves. The campaigns are characterized by continuous viewing by HRDI in 2 viewing directions, for periods of 10-12 days. Data sampled in this manner lend themselves quite well to "asynoptic spectral analysis", from which motions with periods as low as one day can be retrieved with relatively minimal aliasing.

Lieberman, Ruth↗
NASA NTRS2018

The Planetary Materials Database

NASA provides funds for a variety of research programs whose principal focus is to collect and analyze terrestrial analog materials. These data are used to (1) understand and interpret planetary geology; (2) identify and characterize habitable environments and pre-biotic/biotic processes; (3) interpret returned data from present and past missions; and (4) evaluate future mission and instrument concepts prior to selection for flight. Data management plans are now required for these programs, but the collected data are still not generally available to the community. There is also little possibility to re-analyze the collected materials by other techniques, since there is no requirement to archive collected samples. The Planetary Materials Database (PMD) is a central, high-quality, long-term data repository, which aims to promote the field of astrobiology and increase scientific returns from NASA funded research by enabling data sharing, collaboration and exposure of non-NASA scientists to NASA research initiatives and missions. The PMD is a linked collection of databases developed using the Open Data Repository (ODR) system. The PMD will include detailed descriptions of terrestrial analog planetary materials as well as data from the instruments used in their analysis. The goal is to provide example patterns/spectra/analyses, etc. and background information suitable for use by the Space Science community. An early example showing the utility of these databases (although not in the ODR format) is the RRUFF mineral database. RRUFF, comprising 4,000+ pure mineral standards, is the most popular and widely used dataset of minerals and receives more than 180,000 queries per week from geologists and mineralogists worldwide. The PMD will be patterned after the CheMin database [3], a resource that contains all of the data collected by the MSL CheMin XRD instrument on Mars. Raw and processed CheMin data can be viewed, downloaded, reprocessed and reanalyzed using cloud-based “applications” linked to the data.

Blake, David↗
NASA NTRS2011

Flow Quality Survey of the NASA Ames 11-by 11-Ft Transonic Wind Tunnel

New baseline turbulence levels have been measured using a new CTA and new hot-wire sensors. Levels remain the same as measured in 1999. Data and methodology documented (almost). New baseline acoustics levels have been measured up to Mach 1.35. -Levels are higher than reported in 1999. -Data and methodology documented (almost). Application of fairings to the strut trailing edge showed up to a 10% reduction in the tunnel background noise. Data analysis and documentation for publishing is ongoing.

Amaya, Max A.↗
NASA NTRS1973

Thermoelectric Outer Planets Spacecraft (TOPS)

The research and advanced development work is reported on a ballistic-mode, outer planet spacecraft using radioisotope thermoelectric generator (RTG) power. The Thermoelectric Outer Planet Spacecraft (TOPS) project was established to provide the advanced systems technology that would allow the realistic estimates of performance, cost, reliability, and scheduling that are required for an actual flight mission. A system design of the complete RTG-powered outer planet spacecraft was made; major technical innovations of certain hardware elements were designed, developed, and tested; and reliability and quality assurance concepts were developed for long-life requirements. At the conclusion of its active phase, the TOPS Project reached its principal objectives: a development and experience base was established for project definition, and for estimating cost, performance, and reliability; an understanding of system and subsystem capabilities for successful outer planets missions was achieved. The system design answered long-life requirements with massive redundancy, controlled by on-board analysis of spacecraft performance data.

Source record↗
NASA NTRS1979

Development and demonstration of manufacturing processes for fabricating graphite/PMR-15 polyimide structural elements

The processing requirements for graphite/PMR-15 polyimide composites developed to demonstrate the structural integrity of polyimide composite structural elements at temperatures up to 589K (600 F) are described. Major tasks included: quality assurance development; materials and process development; specification verification; flat panel fabrication; stiffened panel fabrication; honeycomb panel fabrication; chopped fiber moldings; and demonstration component fabrication. Materials, processing, and quality assurance documents were prepared from experimentally derived data. Structural elements consisting of flat panels, corrugated stiffeners, I-beams, hat stiffeners, honeycomb panels, and chopped fiber moldings were made and tested. Property data from 219K (-65 F) to 589K (600 F) were obtained. All elements were made in a production environment. The size of each element was sufficient to insure production capability and structural component applicability. Problems associated with adhesive bonding, laminate and structural element analysis, material variability, and test methods were addressed.

Sheppard, C. H.↗
NASA NTRS1994

Coronal temperatures of unusually active K-dwarf binary systems

We report the results of a ROSAT pointed study of 4 BY Dra systems. Good quality pulse-height spectra are available from all four systems. Except for a required interstellar absorption component in HD 319139, the four systems have remarkably similar x-ray spectra; the two systems BD +22deg.669 and BD +23deg.635 look virtually identical in x rays. Analysis of the 4 x-ray spectra reveals that, in all cases, a single-temperature hot plasma (RS or Mewe) spectra is inadequate to fit the data, and two temperatures are required. We present examples of fitted pulse-height spectra and chi squared contours in kT(sub 1)-kT(sub 2) space.

Stern, Robert A.↗
NASA NTRS1994

Measurement Capabilities of Single-Pulse Planar Doppler Velocimetry

Preliminary investigations are described of a method that is capable of measuring instantaneous, 3-D, velocity vectors everywhere in a light sheet generated by a pulsed laser. The technique, here called Planar Doppler Velocimetry (PDV), is a variation of a new concept for velocity measurements that was called Doppler Global Velocimetry (DGV) in its original disclosure. The concept relies on the use of a narrowband laser and measurements of the Doppler shift of scattered light from particles moving with a flow. The Doppler shift is recorded as a variation in transmission through a sharp-edged spectral filter provided by iodine vapor in a cell. Entire fields of velocity can be determined by using a solid-state camera to record the intensity variations throughout the field of view. However, the implementation of DGV has been centered principally on the use of high power, continuous-wave, ion lasers and measurement times that are determined by the 30-ms framing times of standard video cameras. Hence, they provide velocity fields that are averaged in time at least over that period. On the other hand, the PDV concept described in this presentation incorporates a high energy, repetitively pulsed, Nd-YAG laser that is injection-seeded to make it narrowband and then frequency-doubled to provide light at frequencies absorbed by the iodine vapor. The duration of each pulse is less than 10 nanoseconds. When used in combination with nonstandard, scientific quality, solid state cameras, a sequence of images can be obtained that provides instantaneous velocity vectors everywhere in the field of view. The investigations described in this paper include an accurate characterization of the iodine cell spectral behavior and its influence on the PDV measurements, a derivation of the PDV signal analysis requirements, and the unique aspects of the pulsed laser behavior related to this application. In addition, PDV measurements are to be demonstrated using data from a rotating wheel target and from the flow of a subsonic jet. Initially, single optical fiber light collection and photomultiplier detectors will be substituted for solid state cameras. Those results will allow the determination of the fundamental limitations of the PDV technique without the complications of image acquisition and processing. They will then be used to provide an analysis of the measurement capabilities of PDV both in small aerodynamic research wind tunnels and in large wind tunnels designed for production airframe and propulsion testing. Future plans include the implementation of solid state cameras and the development of the required image acquisition and processing software. Eventually, the PDV technique will be applied to an aerodynamic research program related to transonic wing flutter.

McKenzie, Robert L.↗
NASA NTRS2005

Cold Flow Plume Entrainment Test Final Report NTF Test Number 2456

As part of the Space Shuttle Return to Flight (RTF) program, Marshall Space Flight Center (MSFC) performed computational fluid dynamics (CFD) analysis to define the velocity flowfields around the Shuttle stack at liftoff. These CFD predicted velocity flowfields were used in debris transport analysis (DTA). High speed flows such as plumes induce or 'entrain' mass from the surrounding environment. Previous work had shown that CFD analysis over-predicts plume induced flows. Therefore, the DTA would tend to 1) predict more debris impacts, and 2) the debris velocity (and kinetic energy) of those impacts would be too high. At a November, 2004 peer-review it was recommended that the Liftoff DTA team quantify the uncertainty in the DTA caused by the CFD's over prediction of plume induced flow. To do so, the Liftoff DTA team needed benchmark quality data for plume induced flow to quantify the CFD accuracy and its effect on the DTA. MSFC's Nozzle Test Facility (NTF) conducted the "Nozzle Induced Flows test, P#2456" to obtain experimental data for plume induced flows for nozzle flow exhausting into q quiescent freestream. Planning for the test began in December, 2004 and the experimental data was obtained in February and March of 2005. The funding for this test was provided by MSFC's Space Shuttle Propulsion Systems Integration and Engineering office.

Ruf, Joseph H.↗
NASA NTRS2017

The High Definition Earth Viewing (HDEV) Payload

The High Definition Earth Viewing (HDEV) payload enables long-term experimentation of four, commercial-of-the-shelf (COTS) high definition video, cameras mounted on the exterior of the International Space Station. The payload enables testing of cameras in the space environment. The HDEV cameras transmit imagery continuously to an encoder that then sends the video signal via Ethernet through the space station for downlink. The encoder, cameras, and other electronics are enclosed in a box pressurized to approximately one atmosphere, containing dry nitrogen, to provide a level of protection to the electronics from the space environment. The encoded video format supports streaming live video of Earth for viewing online. Camera sensor types include charge-coupled device and complementary metal-oxide semiconductor. Received imagery data is analyzed on the ground to evaluate camera sensor performance. Since payload deployment, minimal degradation to imagery quality has been observed. The HDEV payload continues to operate by live streaming and analyzing imagery. Results from the experiment reduce risk in the selection of cameras that could be considered for future use on the International Space Station and other spacecraft. This paper discusses the payload development, end-to- end architecture, experiment operation, resulting image analysis, and future work.

Muri, Paul↗
NASA NTRS2016

The Pilatus Unmanned Aircraft System for Lower Atmospheric Research

This paper presents details of the University of Colorado (CU) "Pilatus" unmanned research aircraft, assembled to provide measurements of aerosols, radiation and thermodynamics in the lower troposphere. This aircraft has a wingspan of 3.2 m and a maximum take-off weight of 25 kg, and it is powered by an electric motor to reduce engine exhaust and concerns about carburetor icing. It carries instrumentation to make measurements of broadband up- and downwelling shortwave and longwave radiation, aerosol particle size distribution, atmospheric temperature, relative humidity and pressure and to collect video of flights for subsequent analysis of atmospheric conditions during flight. In order to make the shortwave radiation measurements, care was taken to carefully position a high-quality compact inertial measurement unit (IMU) and characterize the attitude of the aircraft and its orientation to the upward-looking radiation sensor. Using measurements from both of these sensors, a correction is applied to the raw radiometer measurements to correct for aircraft attitude and sensor tilt relative to the sun. The data acquisition system was designed from scratch based on a set of key driving requirements to accommodate the variety of sensors deployed. Initial test flights completed in Colorado provide promising results with measurements from the radiation sensors agreeing with those from a nearby surface site. Additionally, estimates of surface albedo from onboard sensors were consistent with local surface conditions, including melting snow and bright runway surface. Aerosol size distributions collected are internally consistent and have previously been shown to agree well with larger, surface-based instrumentation. Finally the atmospheric state measurements evolve as expected, with the near-surface atmosphere warming over time as the day goes on, and the atmospheric relative humidity decreasing with increased temperature. No directional bias on measured temperature, as might be expected due to uneven heating of the sensor housing over the course of a racetrack pattern, was detected. The results from these flights indicate that the CU Pilatus platform is capable of performing research-grade lower tropospheric measurement missions.

de Boer, Gijs↗
NASA NTRS1985

Closed-loop, pilot/vehicle analysis of the approach and landing task

Optimal-control-theoretic modeling and frequency-domain analysis is the methodology proposed to evaluate analytically the handling qualities of higher-order manually controlled dynamic systems. Fundamental to the methodology is evaluating the interplay between pilot workload and closed-loop pilot/vehicle performance and stability robustness. The model-based metric for pilot workload is the required pilot phase compensation. Pilot/vehicle performance and loop stability is then evaluated using frequency-domain techniques. When these techniques were applied to the flight-test data for thirty-two highly-augmented fighter configurations, strong correlation was obtained between the analytical and experimental results.

Schmidt, D. K.↗
NASA NTRS1998

International Solar-Terrestrial Program Key Parameter Visualization Tool Data: USA_NASA_DDF_ISTP_KP_0057

The Global Geospace Science Program (GGS) is designed to improve greatly the understanding of the flow of energy, mass and momentum in the solar-terrestrial environment with particular emphasis on "Geospace". The Global Geospace Science Program is the US contribution to the International Solar-Terrestrial Physics (ISTP) Science Initiative. This CD-ROM issue describes the WIND and POLAR spacecraft, the scientific experiments carried onboard, the Theoretical and Ground Based investigations which constitute the US Global Geospace Science Program and the ISTP Data Systems which support the data acquisition and analysis effort. The International Solar-Terrestrial Physics Program (ISTP) Key Parameter Visualization Tool (KPVT), provided on the CD-ROM, was developed at the ISTP Science Planning and Operations Facility (SPOF). The KPVT is a generic software package for visualizing the key parameter data produced from all ISTP missions, interactively and simultaneously. The tool is designed to facilitate correlative displays of ISTP data from multiple spacecraft and instruments, and thus the selection of candidate events and data quality control. The software, written in IDL, includes a graphical/widget user interface, and runs on many platforms, including various UNIX workstations, Alpha/Open VMS, Macintosh (680x0 and PowerPC), and PC/Windows NT, Windows 3.1, and Windows 95.

Ocuna, M. H.↗
NASA NTRS1998

International Solar-Terrestrial Program Key Parameter Visualization Tool Data: USA_NASA_DDF_ISTP_KP_0056

The Global Geospace Science Program (GGS) is designed to improve greatly the understanding of the flow of energy, mass and momentum in the solar-terrestrial environment with particular emphasis on "Geospace". The Global Geospace Science Program is the US contribution to the International Solar-Terrestrial Physics (ISTP) Science Initiative. This CD-ROM issue describes the WIND and POLAR spacecraft, the scientific experiments carried onboard, the Theoretical and Ground Based investigations which constitute the US Global Geospace Science Program and the ISTP Data Systems which support the data acquisition and analysis effort. The International Solar-Terrestrial Physics Program (ISTP) Key Parameter Visualization Tool (KPVT), provided on the CD-ROM, was developed at the ISTP Science Planning and Operations Facility (SPOF). The KPVT is a generic software package for visualizing the key parameter data produced from all ISTP missions, interactively and simultaneously. The tool is designed to facilitate correlative displays of ISTP data from multiple spacecraft and instruments, and thus the selection of candidate events and data quality control. The software, written in IDL, includes a graphical/widget user interface, and runs on many platforms, including various UNIX workstations, Alpha/Open VMS, Macintosh (680x0 and PowerPC), and PC/Windows NT, Windows 3.1, and Windows 95.

Ocuna, M. H.↗
NASA NTRS1998

International Solar-Terrestrial Program Key Parameter Visualization Tool Data: USA_NASA_DDF_ISTP_IM_KP_0034

The Global Geospace Science Program (GGS) is designed to improve greatly the understanding of the flow of energy, mass and momentum in the solar-terrestrial environment with particular emphasis on "Geospace". The Global Geospace Science Program is the US contribution to the International Solar-Terrestrial Physics (ISTP) Science Initiative. This CD-ROM issue describes the WIND and POLAR spacecraft, the scientific experiments carried onboard, the Theoretical and Ground Based investigations which constitute the US Global Geospace Science Program and the ISTP Data Systems which support the data acquisition and analysis effort. The International Solar-Terrestrial Physics Program (ISTP) Key Parameter Visualization Tool (KPVT), provided on the CD-ROM, was developed at the ISTP Science Planning and Operations Facility (SPOF). The KPVT is a generic software package for visualizing the key parameter data produced from all ISTP missions, interactively and simultaneously. The tool is designed to facilitate correlative displays of ISTP data from multiple spacecraft and instruments, and thus the selection of candidate events and data quality control. The software, written in IDL, includes a graphical/widget user interface, and runs on many platforms, including various UNIX workstations, Alpha/Open VMS, Macintosh (680x0 and PowerPC), and PC/Windows NT, Windows 3.1, and Windows 95.

Ocuna, M. H.↗
NASA NTRS1998

International Solar-Terrestrial Program Key Parameter Visualization Tool Data: USA_NASA_DDF_ISTP_IM_KP_0033

The Global Geospace Science Program (GGS) is designed to improve greatly the understanding of the flow of energy, mass and momentum in the solar-terrestrial environment with particular emphasis on "Geospace". The Global Geospace Science Program is the US contribution to the International Solar-Terrestrial Physics (ISTP) Science Initiative. This CD-ROM issue describes the WIND and POLAR spacecraft, the scientific experiments carried onboard, the Theoretical and Ground Based investigations which constitute the US Global Geospace Science Program and the ISTP Data Systems which support the data acquisition and analysis effort. The International Solar-Terrestrial Physics Program (ISTP) Key Parameter Visualization Tool (KPVT), provided on the CD-ROM, was developed at the ISTP Science Planning and Operations Facility (SPOF). The KPVT is a generic software package for visualizing the key parameter data produced from all ISTP missions, interactively and simultaneously. The tool is designed to facilitate correlative displays of ISTP data from multiple spacecraft and instruments, and thus the selection of candidate events and data quality control. The software, written in IDL, includes a graphical/widget user interface, and runs on many platforms, including various UNIX workstations, Alpha/Open VMS, Macintosh (680x0 and PowerPC), and PC/Windows NT, Windows 3.1, and Windows 95.

Ocuna, M. H.↗