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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 829 records · Page 46
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NASA NTRS1996

STS-74 Mission Highlights Resource Tape

The flight crew of the STS-74 Space Shuttle Orbiter Atlantis Cmdr. Ken Cameron, Pilot Jim Halsell, and Mission Specialists Chris Hadfield, Jerry Ross, and William McArthur present an overview of their flight mission, whose primary objective is the rendezvous and space docking with the Russian Mir Space Station. Video film footage includes the following: prelaunch and launch activities; shuttle launch; in-orbit rendezvous; installation of the Russian-made docking module; in-orbit docking between Mir and the orbiter; general crew activities; transfer of supplies, equipment, and a crystal growth experiment to Mir; data collection from Mir thruster firings; undocking maneuvers and a Mir fly around; pre-return checkout of flight systems; and the reentry and landing of the orbiter. Earth views include horizon sunsets, atmospheric boundary layers, and a variety of geographical location footage (New Orleans; Atlanta; James Bay, Canada; Poland; Turkey; Mt. Pinatubo, Philippines; Salt Lake City, Utah; and Colorado).

Source record↗
NASA NTRS1996

The Aggregate Representation of Terrestrial Land Covers Within Global Climate Models (GCM)

This project had four initial objectives: (1) to create a realistic coupled surface-atmosphere model to investigate the aggregate description of heterogeneous surfaces; (2) to develop a simple heuristic model of surface-atmosphere interactions; (3) using the above models, to test aggregation rules for a variety of realistic cover and meteorological conditions; and (4) to reconcile biosphere-atmosphere transfer scheme (BATS) land covers with those that can be recognized from space; Our progress in meeting these objectives can be summarized as follows. Objective 1: The first objective was achieved in the first year of the project by coupling the Biosphere-Atmosphere Transfer Scheme (BATS) with a proven two-dimensional model of the atmospheric boundary layer. The resulting model, BATS-ABL, is described in detail in a Masters thesis and reported in a paper in the Journal of Hydrology Objective 2: The potential value of the heuristic model was re-evaluated early in the project and a decision was made to focus subsequent research around modeling studies with the BATS-ABL model. The value of using such coupled surface-atmosphere models in this research area was further confirmed by the success of the Tucson Aggregation Workshop. Objective 3: There was excellent progress in using the BATS-ABL model to test aggregation rules for a variety of realistic covers. The foci of attention have been the site of the First International Satellite Land Surface Climatology Project Field Experiment (FIFE) in Kansas and one of the study sites of the Anglo-Brazilian Amazonian Climate Observational Study (ABRACOS) near the city of Manaus, Amazonas, Brazil. These two sites were selected because of the ready availability of relevant field data to validate and initiate the BATS-ABL model. The results of these tests are given in a Masters thesis, and reported in two papers. Objective 4: Progress far exceeded original expectations not only in reconciling BATS land covers with those that can be recognized from space, but also in then applying remotely-sensed land cover data to map aggregate values of BATS parameters for heterogeneous covers and interpreting these parameters in terms of surface-atmosphere exchanges.

Shuttleworth, W. James↗
NASA NTRS1996

ACTS Aeronautical Terminal Experiment System Description and Link Analysis

During the summer of 1994, the performance of an experimental mobile satellite communication system was demonstrated to industry and government representatives by the NASA Lewis Research Center (LeRC) and the Jet Propulsion Laboratory (JPL). The system was based on the advanced communications technology satellite (ACTS) and consisted of a K-/Ka-band active monolithic microwave integrated circuit (MMIC) phased array antenna system, ACTS mobile terminal (AMT) and link evaluation terminal (LET). A LeRC research aircraft, Learjet model 25, was outfitted with the active MMIC phased array antenna system and AMT and served as the experimental 20/30 Ghz aeronautical terminal. The LET at LeRC in Cleveland, OH, was interfaced with portions of fixed-AMT equipment and together provided the gateway station functions including ACTS interface and public service telephone network (PSTN) interface. The ACTS was operated in its microwave switch matrix (MSM) mode with a spot beam for the Learjet and another spot beam dedicated to the LET. The Learjet was flown over several major cities across the US and demonstrated the feasibility of a full-duplex compressed voice links for an aeronautical terminal through the 20/30 Ghz ACTS channel. This paper presents a technical description of the system including the MMIC phased array antenna system, AMT, Learjet, LET, and ACTS. The array antenna system consists of a 30 Ghz transmit array (LeRc/Texas Instruments) and two 20 Ghz receive arrays (USAF Rome Lab., Boeing, and Martin Marietta), each one very small with sufficient performance for a satellite voice link. The AMT consists of 2.4/4.8/9.6 Kbps voice coder/decoder, modem, PSTN interface and RF/IF converters. Link analysis is presented and compared to the actual performance data collected during the demonstration flights.

Sohn, Philip↗
NASA NTRS1995

TAP/ASTA Flight Demo Data Analysis

Recently the Low Visibility Landing and Surface Operations (LVLASO) project team of the Systems Integration Branch at the NASA Langley Research Center completed a flight demonstration of TAP/ASTA concepts at the Atlantic City airport. This paper is concerned with the analysis of the aircraft data that was recorded by the test vehicle during the duration of the flight demonstrations.

Mejdrich, Eric↗
NASA NTRS1997

Total Solar Eclipse of 1999 August 11

On 1999 August 11, a total eclipse of the Sun will be visible from within a narrow corridor which traverses the Eastern Hemisphere. The path of the Moon's umbral shadow begins in the Atlantic and crosses central Europe, the Middle East, and India, where it ends at sunset in the Bay of Bengal. A partial eclipse will be seen within the much broader path of the Moon's penumbral shadow, which includes northeastern North America, all of Europe, northern Africa, and the western half of Asia. Detailed predictions for this event are presented and include besselian elements, geographic coordinates of the path of totality, physical ephemeris of the umbra, topocentric limb profile corrections, local circumstances for approximately 1400 cities, maps of the eclipse path, weather prospects, the lunar limb profile, and the sky during totality. Tips and suggestions are also given on how to safely view and photograph the eclipse.

Espenak, Fred↗
NASA NTRS1997

Piloted Simulation Tests of Propulsion Control as Backup to Loss of Primary Flight Controls for a B747-400 Jet Transport

Partial failures of aircraft primary flight control systems and structural damages to aircraft during flight have led to catastrophic accidents with subsequent loss of lives (e.g. DC-10, B-747, C-5, B-52, and others). Following the DC-10 accident at Sioux City, Iowa in 1989, the National Transportation Safety Board recommended 'Encourage research and development of backup flight control systems for newly certified wide-body airplanes that utilize an alternate source of motive power separate from that source used for the conventional control system.' This report describes the concept of a propulsion controlled aircraft (PCA), discusses pilot controls, displays, and procedures; and presents the results of a PCA piloted simulation test and evaluation of the B747-400 airplane conducted at NASA Ames Research Center in December, 1996. The purpose of the test was to develop and evaluate propulsion control throughout the full flight envelope of the B747-400 including worst case scenarios of engine failures and out of trim moments. Pilot ratings of PCA performance ranged from adequate to satisfactory. PCA performed well in unusual attitude recoveries at 35,000 ft altitude, performed well in fully coupled ILS approaches, performed well in single engine failures, and performed well at aft cg. PCA performance was primarily limited by out-of-trim moments.

Bull, John↗
NASA NTRS1997

Incipient Melt Formation and Devitrification at the Wanapitei Impact Structure, Ontario, Canada

The Wanapitei impact structure is approximately 8 km in diameter and lies within Wanapitei Lake, approximately 34 km northeast of the city of Sudbury. Rocks related to the 37 Ma impact event are found only in Pleistocene glacial deposits south of the lake. Most of the target rocks are metasedimentary rocks of the Proterozoic Huronian Supergroup. An almost completely vitrified, inclusion-bearing sample investigated here represents either an impact melt or a strongly shock metamorphosed, pebbly wacke. In the second, preferred interpretation, a number of partially melted and devitrified clasts are enclosed in an equally highly shock metamorphosed arkosic wacke matrix (i.e., the sample is a shocked pebbly wacke), which records the onset of shock melting. This interpretation is based on the glass composition, mineral relicts in the glass, relict rock textures, and the similar degree of shock metamorphism and incipient melting of all sample components. Boulder matrix and clasts are largely vitrified and preserve various degrees of fluidization, vesiculation, and devitrification. Peak shock pressure of approximately 50-60 GPa and stress experienced by the sample were somewhat below those required for complete melting and development of a homogeneous melt. The rapid cooling and devitrification history of the analyzed sample is comparable to that reported recently from glasses in the suevite of the Ries impact structure in Germany and may indicate that the analyzed sample experienced an annealing temperature after deposition of somewhere between 650 C and 800 C.

Dressler, B. O.↗
NASA NTRS1997

XV-15 Structural-Acoustic Data

Tiltrotor aircraft are a potentially viable means of intercity travel. The tiltrotor is able to transport passengers relatively quickly from the center of a city to destinations within a 300-mile radius. For such vehicles to be commercially viable, the interior noise and vibration levels must be acceptable to the passengers. A review of the literature revealed very little structural-acoustic data related to the tiltrotor. For this reason, structural-acoustic measurements were taken aboard an XV-15 tiltrotor. The six flight conditions included five in level flight, nominally 140-220 knots, for airplane mode (nacelle at 0 degrees) and one out-of-ground-effect (OGE) hover (nacelle at 90 degrees). The flight test measurements included nine exterior surface pressures, five structural accelerations, and two interior pressures. These sensors were located near the tip path plane on the port side of the aircraft. One minute of data was acquired at each condition. The data is presented as time histories, autospectra, coherence functions, and cross-spectra. In general, for level flight, the measured data showed very little effect of forward flight speed except to change the amplitude of the response; however, the character of the response was found to be dependent on spatial location. In contrast, in the hover mode the spatial location had very little effect on the character of the response. Additionally, the report highlights: the coherence between the transducer data and the rotor tach signal; and transfer function calculations between the exterior pressures.

Lyle, Karen H.↗
NASA NTRS1997

NASA's Involvement in Technology Development and Transfer: The Ohio Hybrid Bus Project

A government and industry cooperative is using advanced power technology in a city transit bus that will offer double the fuel economy, and reduce emissions to one tenth of government standards. The heart of the vehicle's power system is a natural gas fueled generator unit. Power from both the generator and an advanced energy storage system is provided to a variable speed electric motor attached to the rear drive axle. A unique aspect of the vehicle's design is its use of "super" capacitors for recovery of energy during braking. This is the largest vehicle ever built using this advanced energy recovery technology. This paper describes the project goals and approach, results of its system performance modeling, and the status of the development team's effort.

Viterna, Larry A.↗
NASA NTRS1997

Hybrid Electric Transit Bus

A government, industry, and university cooperative is developing an advanced hybrid electric city transit bus. Goals of this effort include doubling the fuel economy compared to current buses and reducing emissions to one-tenth of current EPA standards. Unique aspects of the vehicle's power system include the use of ultra-capacitors as an energy storage system, and a planned natural gas fueled turbogenerator developed from a small jet engine. Power from both the generator and energy storage system is provided to a variable speed electric motor attached to the rear axle. At over 15000 kg gross weight, this is the largest vehicle of its kind ever built using ultra-capacitor energy storage. This paper describes the overall power system architecture, the evolution of the control strategy, and its performance over industry standard drive cycles.

Viterna, Larry A.↗
NASA NTRS1998

Project ATLANTA (ATlanta Land-use ANalysis: Temperature and Air quality): A Study of how the Urban Landscape Affects Meteorology and Air Quality Through Time

It is our intent through this investigation to help facilitate measures that can be Project ATLANTA (ATlanta Land-use ANalysis: applied to mitigate climatological or air quality Temperature and Air-quality) is a NASA Earth degradation, or to design alternate measures to sustain Observing System (EOS) Interdisciplinary Science or improve the overall urban environment in the future. investigation that seeks to observe, measure, model, and analyze how the rapid growth of the Atlanta. The primary objectives for this research effort are: 1) To In the last half of the 20th century, Atlanta, investigate and model the relationship between Atlanta Georgia has risen as the premier commercial, urban growth, land cover change, and the development industrial, and transportation urban area of the of the urban heat island phenomenon through time at southeastern United States. The rapid growth of the nested spatial scales from local to regional; 2) To Atlanta area, particularly within the last 25 years, has investigate and model the relationship between Atlanta made Atlanta one of the fastest growing metropolitan urban growth and land cover change on air quality areas in the United States. The population of the through time at nested spatial scales from local to Atlanta metropolitan area increased 27% between 1970 regional; and 3) To model the overall effects of urban and 1980, and 33% between 1980-1990 (Research development on surface energy budget characteristics Atlanta, Inc., 1993). Concomitant with this high rate of across the Atlanta urban landscape through time at population growth, has been an explosive growth in nested spatial scales from local to regional. Our key retail, industrial, commercial, and transportation goal is to derive a better scientific understanding of how services within the Atlanta region. This has resulted in land cover changes associated with urbanization in the tremendous land cover change dynamics within the Atlanta area, principally in transforming forest lands to metropolitan region, wherein urbanization has urban land covers through time, has, and will, effect consumed vast acreas of land adjacent to the city local and regional climate, surface energy flux, and air proper and has pushed the rural/urban fringe farther quality characteristics. Allied with this goal is the and farther away from the original Atlanta urban core. prospect that the results from this research can be An enormous transition of land from forest and applied by urban planners, environmental managers agriculture to urban land uses has occurred in the and other decision-makers, for determining how Atlanta area in the last 25 years, along with subsequent urbanization has impacted the climate and overall

Quattrochi, Dale A.↗
NASA NTRS1998

Graphite Fiber Textile Preform/Cooper Matrix Composites

The purpose of this research was to produce a finned tube constructed of a highly conductive braided graphite fiber preform infiltrated with a copper matrix. In addition, the tube was to be fabricated with an integral geometry. The preform was integral in the sense that the tube and the fin could be braided to yield one continuous part. This composite component is a candidate for situations with high heat transmitting and radiation requirements. A proof-of-concept finned tube was braided and infiltrated with a copper matrix proving that a viable process was developed to fabricate the desired component. Braiding of high conductivity carbon fibers required much trial-and-error and development of special procedures. There are many tradeoffs between braidability and fiber conductivity. To understand the properties and structure of the braided finned tube, an geometric model of the braid structure was derived. This derivation set the basis for the research because knowing the tow orientations helped decipher the thermal as well as the mechanical and conduction tendencies. Infiltration of the fibers into a copper matrix was a complex procedure, and was performed by TRA, of Salt Lake City, Utah, using a proprietary process. Several batches were fabricated with a final, high quality batch serving as a confirming proof-of-concept.

Filatovs, George J.↗
NASA NTRS1999

Baseline Testing of the Hybrid Electric Transit Bus

A government, industry and academic cooperative has developed a Hybrid Electric Transit Bus (HETB). Goals of the program include doubling the fuel economy of city transit buses currently in service, and reducing emissions to one-tenth of EPA standards. Unique aspects of the vehicle's power system include the use of ultra-capacitors for the energy storage system and the planned use of a natural gas fueled turbogenerator, to be developed from a small jet engine. At over 17000 kg gross weight, this is the largest vehicle to use ultra-capacitor energy storage. A description of the HETB, the results of performance testing, and future vehicle development plans are the subject of this report.

Brown, Jeffrey C.↗
NASA NTRS1999

The Chancellor's Model School Project (CMSP)

What does it take to create and implement a 7th to 8th grade middle school program where the great majority of students achieve at high academic levels regardless of their previous elementary school backgrounds? This was the major question that guided the research and development of a 7-year long project effort entitled the Chancellor's Model School Project (CMSP) from September 1991 to August 1998. The CMSP effort conducted largely in two New York City public schools was aimed at creating and testing a prototype 7th and 8th grade model program that was organized and test-implemented in two distinct project phases: Phase I of the CMSP effort was conducted from 1991 to 1995 as a 7th to 8th grade extension of an existing K-6 elementary school, and Phase II was conducted from 1995 to 1998 as a 7th to 8th grade middle school program that became an integral part of a newly established 7-12th grade high school. In Phase I, the CMSP demonstrated that with a highly structured curriculum coupled with strong academic support and increased learning time, students participating in the CMSP were able to develop a strong foundation for rigorous high school coursework within the space of 2 years (at the 7th and 8th grades). Mathematics and Reading test score data during Phase I of the project, clearly indicated that significant academic gains were obtained by almost all students -- at both the high and low ends of the spectrum -- regardless of their previous academic performance in the K-6 elementary school experience. The CMSP effort expanded in Phase II to include a fully operating 7-12 high school model. Achievement gains at the 7th and 8th grade levels in Phase II were tempered by the fact that incoming 7th grade students' academic background at the CMSP High School was significantly lower than students participating in Phase 1. Student performance in Phase II was also affected by the broadening of the CMSP effort from a 7-8th grade program to a fully functioning 7-12 high school which as a consequence lessened the focus and structure available to the 7-8th grade students and teachers -- as compared to Phase I. Nevertheless, the CMSP does represent a unique curriculum model for 7th and 8th grade students in urban middle schools. Experience in both Phase I and Phase II of the project allowed the CMSP to be developed and tested along the broad range of parameters and characteristics that embody an operating public school in an urban environment.

Lopez, Gil↗
NASA NTRS1974

Ships/Trains/Planes/Automobiles: A Renaissance of their Interface

This paper highlights some of the major multi-modal interface problems created by technological advances, socio-political individualism and the flexibility of choices we expect from our transportation modes. The emphasis is on the need for a comprehensive national network of multi-modal priorities to enhance the movement of people and goods within the changing physical shape of our cities.

Allan, Stanley N.↗
NASA NTRS1997

Environmental Assessment and Monitoring with ICAMS (Image Characterization and Modeling System) Using Multiscale Remote-Sensing Data

With the rapid increase in spatial data, especially in the NASA-EOS (Earth Observing System) era, it is necessary to develop efficient and innovative tools to handle and analyze these data so that environmental conditions can be assessed and monitored. A main difficulty facing geographers and environmental scientists in environmental assessment and measurement is that spatial analytical tools are not easily accessible. We have recently developed a remote sensing/GIS software module called Image Characterization and Modeling System (ICAMS) to provide specialized spatial analytical tools for the measurement and characterization of satellite and other forms of spatial data. ICAMS runs on both the Intergraph-MGE and Arc/info UNIX and Windows-NT platforms. The main techniques in ICAMS include fractal measurement methods, variogram analysis, spatial autocorrelation statistics, textural measures, aggregation techniques, normalized difference vegetation index (NDVI), and delineation of land/water and vegetated/non-vegetated boundaries. In this paper, we demonstrate the main applications of ICAMS on the Intergraph-MGE platform using Landsat Thematic Mapper images from the city of Lake Charles, Louisiana. While the utilities of ICAMS' spatial measurement methods (e.g., fractal indices) in assessing environmental conditions remain to be researched, making the software available to a wider scientific community can permit the techniques in ICAMS to be evaluated and used for a diversity of applications. The findings from these various studies should lead to improved algorithms and more reliable models for environmental assessment and monitoring.

Lam, N.↗
NASA NTRS1998

Light Scattering by Nonspherical Particles

Improved understanding of electromagnetic scattering by nonspherical particles is important to many science and engineering disciplines and was the subject of the Conference on Light Scattering by Nonspherical Particles: Theory, Measurements, and Applications. The conference was held 29 September-1 October 1998 at the Goddard Institute for Space Studies in New York City and brought together 115 participants from 18 countries. The main objective of the conference was to highlight and summarize the rapid advancements in the field, including numerical methods for computing the single and multiple scattering of electromagnetic radiation by nonspherical and heterogeneous particles, measurement approaches, knowledge of characteristic features in scattering patterns, retrieval and remote sensing techniques, nonspherical particle sizing, and various practical applications. The conference consisted of twelve oral and one poster sessions. The presentations were loosely grouped based on broad topical categories. In each of these categories invited review talks highlighted and summarized specific active areas of research. To ensure a high-quality conference, all abstracts submitted had been reviewed by members of the Scientific Organizing Committee for technical merit and content. The conference program was published in the June 1998 issue of the Bulletin of the American Meteorological Society and is available on the World Wide Web at http://www.giss.nasa.gov/-crmim/conference/program.html. Authors of accepted papers and review presentations contributed to a volume of preprints published by the American Meteorological Society' and distributed to participants at the conference.

Mishchenko, Michael I.↗
NASA NTRS1971

Computerized Attendance Accounting and Emergency Assistance Communications: Viable Tools in Secondary School Administration

In the late 1968, the Space Technology Application Office at the Jet Propulsion Laboratory (JPL) initiated a pilot study to determine whether technological aids could be developed that would help secondary school administrators cope with the volatile and chaotic situations that often accompany student activism, disorders, and riots. The study was conducted in cooperation with the Sacramento City Unified School District (SCUSD) and at the John F. Kennedy Senior High School (JFK) in Sacramento, California. The problems at JFK and in the SCUSD were identified and described to the JPL team by members of the Kennedy staff and personnel at various levels and departments within the school district. The JPL team of engineers restricted their scope to problems that appeared solvable, or at least partially solvable, through the use of technological systems. Thus far, two hardware systems have been developed for use in the school. The first, a personal emergency assistance communication system, has already been tested operationally at JFK and has met the objectives established for it. The second technological aid developed was a computerized attendance accounting system. This system has been fabricated, tested, and installed at JFK. Full-scale operational testing began in April 1971. While studies and hardware tests were in progress at JFK, contacts were made with several other schools in order that, insofar as practicable, hardware designs could allow for possible adaptation to schools other than JFK.

Roberts, Vasel W.↗