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NASA Network Resource and Training Site
Jul 7, 2019 NASA Technical Reports Server (NTRS)
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Coronal mass ejections (CMEs) and high-speed solar wind streams (HSS) are two solar phenomena that produce large-scale structures in the interplanetary (IP) medium. CMEs evolve into interplanetary CMEs (ICMEs) and the HSS result in corotating interaction regions (CIRs) when they interact with preceding slow solar wind. CMEs and CIRs originate from closed (active region and filament region) and open (corona) hole) magnetic field regions on the Sun, respectively. These two types of mass emissions...
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Topics: NASA Technical Reports Server (NTRS), CORONAL MASS EJECTION, ENVIRONMENT EFFECTS, SOLAR ACTIVITY,...
NASA Network Resource and Training Site
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NASA's In-Space Propulsion Technology Program is investing in technologies that have the potential to revolutionize the robotic exploration of deep space. For robotic exploration and science missions, increased efficiencies of future propulsion systems are critical to reduce overall life-cycle costs and, in some cases, enable missions previously considered impossible. Continued reliance on conventional chemical propulsion alone will not enable the robust exploration of deep space - the maximum...
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Topics: NASA Technical Reports Server (NTRS), SPACECRAFT PROPULSION, TECHNOLOGY ASSESSMENT, NASA PROGRAMS,...
Studies over the last decade have shown radioisotope-based nuclear electric propulsion to be enhancing and, in some cases, enabling for many potential robotic science missions. Also known as radioisotope electric propulsion (REP), the technology offers the performance advantages of traditional reactor-powered electric propulsion (i.e., high specific impulse propulsion at large distances from the Sun), but with much smaller, affordable spacecraft. Future use of REP requires development of...
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Topics: NASA Technical Reports Server (NTRS), NUCLEAR ELECTRIC PROPULSION, HALL THRUSTERS, ION ENGINES,...
Ring current effect on boundary of geomagnetic field in solar wind
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Topic: NASA Technical Reports Server (NTRS)
NASA Network Resource and Training Site
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Bibliography of aeronautical engineering with abstracts
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Topic: NASA Technical Reports Server (NTRS)
This bibliography lists 295 reports, articles, and other documents introduced into the NASA Scientific and Technical Information System in August 1978.
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Topics: NASA Technical Reports Server (NTRS), AERODYNAMICS, AERONAUTICAL ENGINEERING, AERONAUTICS, AIRCRAFT...
NASA Network Resource and Training Site
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This Program User's Guide discusses the Nuclear Thermal Propulsion (NTP) engine system design features and capabilities modeled in the Nuclear Engine System Simulation (NESS): Version 2.0 program (referred to as NESS throughout the remainder of this document), as well as its operation. NESS was upgraded to include many new modeling capabilities not available in the original version delivered to NASA LeRC in Dec. 1991, NESS's new features include the following: (1) an improved input format; (2)...
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Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, NUCLEAR ENGINE FOR ROCKET VEHICLES,...
Studies were conducted to develop appropriate space shuttle electrical power distribution and control (EPDC) subsystem simulation models and to apply the computer simulations to systems analysis of the EPDC. A previously developed software program (SYSTID) was adapted for this purpose. The following objectives were attained: (1) significant enhancement of the SYSTID time domain simulation software, (2) generation of functionally useful shuttle EPDC element models, and (3) illustrative...
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Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, ELECTRIC EQUIPMENT, ELECTRIC POWER...
A narrow-beam (1 degree beamwidth), multi-channel (20 to 30 and 89 GHz), polarized (89 vertical and horizontal) radiometer with full azimuth and elevation scanning capabilities has been built with the purpose of improving the detection of in-flight icing hazards to aircraft in the near airport environment. This goal was achieved by co-locating the radiometer with Colorado State University's CHILL polarized Doppler radar and taking advantage of similar beamwidth and volume scan regiments. In...
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Topics: NASA Technical Reports Server (NTRS), AIRCRAFT ICING, DOPPLER RADAR, RADIOMETERS, AVIATION...
NASA Network Resource and Training Site
Dec 3, 2016 NASA Technical Reports Server (NTRS)
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Linea Research Corporation has developed a wearable noninvasive monitor that provides continuous blood pressure and heart rate measurements in extreme environments. Designed to monitor the physiological effects of astronauts' prolonged exposure to reduced-gravity environments as well as the effectiveness of various countermeasures, the device offers wireless connectivity to allow transfer of both real-time and historical data. It can be modified to monitor the health status of astronaut crew...
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Topics: NASA Technical Reports Server (NTRS), BLOOD PRESSURE, PRESSURE MEASUREMENT, HEART RATE, MONITORS,...
The Space Power Architecture Study (SPAS) identified and evaluated power subsystem options for multimegawatt electric (MMWE) space based weapons and surveillance platforms for the Strategic Defense Initiative (SDI) applications. Steady state requirements of less than 1 MMWE are adequately covered by the SP-100 nuclear space power program and hence were not addressed in the SPAS. Four steady state power systems less than 1 MMWE were investigated with little difference between them on a mass...
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Topics: NASA Technical Reports Server (NTRS), HYDROGEN OXYGEN FUEL CELLS, SPACE POWER REACTORS, SPACECRAFT...
NASA Network Resource and Training Site
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A method of designing a self-adaptive missile guidance system is presented. The system inputs are assumed to be known in a statistical sense only. Newton's modified Wiener theory is utilized in the design of the system and to establish the performance criterion. The missile is assumed to be a beam rider, to have a g limiter, and to operate over a flight envelope where the open-loop gain varies by a factor of 20. It is shown that the percent of time that missile acceleration limiting occurs can...
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Topic: NASA Technical Reports Server (NTRS)
NASA Network Resource and Training Site
Aug 7, 2016 NASA Technical Reports Server (NTRS)
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The crisis which troubles the world market for liquid fuel in general and for carburants in particular is doubtless one of the most serious ever experienced by modern industry. It is a national crisis of economic and political independence for countries like Italy and France. The solutions suggested for meeting the lack of liquid fuel may be summed up under two general headings: the economical use of the petroleum now available; creation of petroleum substitutes from natural sources within the...
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Topic: NASA Technical Reports Server (NTRS)
NASA Network Resource and Training Site
Aug 5, 2016 NASA Technical Reports Server (NTRS)
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This compilation of the outstanding characteristics of the available aircraft engines of the world was prepared as a compact ready reference for desk use. It does not pretend to be anything but a skeleton outline of the characteristics of engines reported in the technical press as being in either the experimental, development, or production stage.
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Topic: NASA Technical Reports Server (NTRS)
Beacon satellite radio Doppler effect for earth geodetic measurements, and Scout launch vehicle for orbital, space probe, and reentry missions
Topic: NASA Technical Reports Server (NTRS)
A wind driven generator was considered as a supplement to a diesel group, for the purpose of economizing fuel when wind power is available. A specific location on Hudson's Bay, Povognituk, was selected. Technical and economic data available for a wind machine of 10-kilowatt nominal capacity and available wind data for that region were used for the study. After subtracting the yearly wind machine costs from savings in fuel costs, a net savings of $1400 per year is realized. These values are...
Topics: NASA Technical Reports Server (NTRS), ECONOMIC ANALYSIS, ELECTRIC POWER SUPPLIES, REMOTE REGIONS,...
The economic feasibility of commercial use of wind generated power in selected areas of Oregon is assessed. A number of machines for generating power have been examined. These include the Savonius rotor, translators, conventional wind turbines, the circulation controlled rotor and the vertical axis winged turbine. Of these machines, the conventional wind turbine and the vertical axis winged turbine show the greatest promise on the basis of the power developed per unit of rotor blade area....
Topics: NASA Technical Reports Server (NTRS), ECONOMIC ANALYSIS, ROTARY WINGS, STRUCTURAL STABILITY,...
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Radio noise continuum emission observed in metric and decametric wave frequencies is discussed. The radio noise is associated with actively varying sunspot groups accompanied by the S-component of microwave radio emissions. It is shown that the S-component emission in microwave frequencies generally occurs several days before the emission of the noise continuum storms of lower frequencies. It is likely that energetic electrons, 10 to 100 Kev, accelerated in association with the variation of...
Topics: NASA Technical Reports Server (NTRS), ELECTRON ENERGY, EXTRATERRESTRIAL RADIATION, MAGNETIC...
There are no author-identified significant results in this report.
Topics: NASA Technical Reports Server (NTRS), ENVIRONMENT EFFECTS, KENTUCKY, MULTISPECTRAL PHOTOGRAPHY,...
Convective instability in the solar corona growth, especially linear growth, was studied. An investigation was also made of nonlinear instability development on a computer. The computer was used to follow a growing perturbation from a small local enhancement in the density of the solar wind to a large increase in the density which would look like one of the rays seen in the sun's corona.
Topics: NASA Technical Reports Server (NTRS), MAGNETIC STARS, PERTURBATION, SOLAR CORONA, COMPUTER...
A description is given of the NASA developed all-weather ice information system for the Great Lakes winter navigation program. The system utilizes an X-band side looking airborne radar (SLAR) for determining type, location, and areal distribution of the ice cover in the Great Lakes and an airborne, S band, down looking short pulse radar for obtaining ice thickness. Digitized SLAR data are relayed in real time via the NOAA-GOES satellite in geosynchronous orbit. The SLAR images along with hand...
Topics: NASA Technical Reports Server (NTRS), GREAT LAKES (NORTH AMERICA), ICE REPORTING, INFORMATION...
There are no author-identified significant results in this report.
Topics: NASA Technical Reports Server (NTRS), COLORADO, CROP INVENTORIES, ERROR ANALYSIS, GRAINS, GREAT...
In order to study the basic mechanisms of erosion, hardened steel balls were shot into annealed 6061 Al alloy targets at velocity of up to 150 m/sec. The projectiles were collected and examined by a scanning electron microscope combined with energy-dispersive X-ray analyzer and it was found that target material in substantial amounts is adhesively transferred to the projectile. The transferred material forms on the projectile surface a layer the thickness of which increases with increases in...
Topics: NASA Technical Reports Server (NTRS), ADHESION, ALUMINUM ALLOYS, EROSION, METAL SURFACES, SURFACE...
Opportunities for commercialization of systems capable of producing hydrogen from solar energy were studied. The hydrogen product costs that might be achieved by the four selected candidate systems was compared with the pricing structure and practices of the commodity gas market. Subsequently, product cost and market price match was noted to exist in the small user sector of the hydrogen marketplace. Barriers to and historical time lags in, commercialization of new technologies are reviewed....
Topics: NASA Technical Reports Server (NTRS), ENERGY POLICY, ENERGY TECHNOLOGY, HYDROGEN PRODUCTION,...
Various aspects of optical heterodyning are considered. Topics covered heterodyning throughout the electromagnetic spectrum including detectors, local oscillators, tunable diode lasers, astronomical systems, and environmental sensors, with both active and passive systems represented.
Topics: NASA Technical Reports Server (NTRS), CONFERENCES, DIODES, INFRARED DETECTORS, OPTICAL...
Kalman filtering techniques are combined with a semianalytical orbit generator to develop a sequential orbit determination algorithm. The algorithm is investigated for computational efficiency, accuracy, and radius of convergence by comparison with truth ephemerides and a Cowell special perturbations filters (GTDS). Test cases relevant to satellite navigation are examined.
Topics: NASA Technical Reports Server (NTRS), EPHEMERIDES, GODDARD TRAJECTORY DETERMINATION SYSTEM, KALMAN...
An electricity producing cell of the reduction-oxidation (REDOX) type divided into two compartments by a membrane is disclosed. A ferrous/ferric couple in a chloride solution serves as a cathode fluid to produce a positive electric potential. A chromic/chromous couple in a chloride solution serves as an anode fluid to produce a negative potential. The electrode is an electrically conductive, inert material plated with copper, silver or gold. A thin layer of lead plates onto the copper, silver...
Topics: NASA Technical Reports Server (NTRS), CURRENT DENSITY, ELECTRODES, ELECTROPLATING, ION PLATING,...
In applying holographic interferometry, opaque objects blocking a portion of the optical beam used to form the interferogram give rise to incomplete data for standard computer tomography algorithms. An experimental technique for circumventing the problem of data blocked by opaque objects is presented. The missing data are completed by forming an interferogram using light backscattered from the opaque object, which is assumed to be diffuse. The problem of fringe localization is considered.
Topics: NASA Technical Reports Server (NTRS), DIFFRACTION PATTERNS, HOLOGRAPHIC INTERFEROMETRY, IMAGE...
Preliminary tribological studies on polyimides formulated from the diamine 2,2-bis 4-(4-aminophenoxy)phenyl hexafluorapane (4-BDAF) indicate that polyimides formulated from this diamine have excellent potential for high temperature tribological applications. The dianhydrides used to make the polyimides were pyromellitic (PMDA) and benzophenonetetracarboxylic acid (BTDA). Friction and wear studies at 25 and 200 C indicate that polyimides formulated using 50 mole percent of the PMDA dianhydride...
Topics: NASA Technical Reports Server (NTRS), DIAMINES, POLYIMIDES, SLIDING FRICTION, TRIBOLOGY, WEAR...
Hot structures fabricated from orthotropic materials are an attractive design option for future high speed vehicles. Joining subassemblies of these materials with standard cylindrical fasteners can lead to loose joints or highly stressed joints due to thermal stress. A method has been developed to eliminate thermal stresses and maintain a tight joint by shaping the fastener and mating hole. This method allows both materials (fastener and structure), with different coefficients of thermal...
Topics: NASA Technical Reports Server (NTRS), AIRCRAFT CONSTRUCTION MATERIALS, FASTENERS, ORTHOTROPISM,...
The exobiology discipline uses ground based and space flight resources to conduct a multidiscipline research effort dedicated to understanding fundamental questions about the origin, evolution, and distribution of life and life related molecules throughout the universe. Achievement of this understanding requires a methodical research strategy which traces the history of the biogenic elements from their origins in stellar formation processes through the chemical evolution of molecules essential...
Topics: NASA Technical Reports Server (NTRS), EXOBIOLOGY, EXPERIMENT DESIGN, GRAVITATIONAL EFFECTS, LIFE...
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Funding strategies are examined for the AIA rocket propulsion strategic plan. Either the government, industry, or universities can fund the project alone, or it was concluded, it works best if is a combination of these sources.
Topics: NASA Technical Reports Server (NTRS), BUDGETING, COST ANALYSIS, GOVERNMENT/INDUSTRY RELATIONS,...
There are no author-identified significant results in this report.
Topics: NASA Technical Reports Server (NTRS), PLANTS (BOTANY), SUSQUEHANNA RIVER BASIN (MD-NY-PA),...
The results of an experimental and theoretical study of many of the fundamental details of sound propagation in hard wall and soft wall annular flow ducts are reported. The theory of sound propagation along such ducts and the theory for determining the complex radiation impedance of higher order modes of an annulus are outlined, and methods for generating acoustic duct modes are developed. The results of a detailed measurement program on propagation in rigid wall annular ducts with and without...
Topics: NASA Technical Reports Server (NTRS), ACOUSTIC DUCTS, ANNULAR FLOW, LININGS, NOISE REDUCTION, SOUND...
The direct arithmetic processing of adaptive delta modulation (ADM) encoded signals, conversion from ADM encoded signals to pulse code modulation (PCM) encoded signals, and conversion from PCM to ADM encoded signals are discussed. It is shown that signals which are ADM encoded can be arithmetically processed directly, without first decoding. Operating on the DM bit stream, and employing only standard digital hardware, the sum, difference and product can be obtained in PCM and ADM format.
Topics: NASA Technical Reports Server (NTRS), DELTA MODULATION, SIGNAL PROCESSING, TECHNOLOGY UTILIZATION,...
Representatives of the U.S., British, French, and Canadian airworthiness authorities participated in a NASA/FAA program to formulate tentative civil airworthiness flight criteria for powered-lift transports. The ultimate limits of the flight envelope are defined by boundaries in the airspeed/path-angle plane. Angle of attack and airspeed margins applied to these ultimate limits provide protection against both atmospheric disturbances and disturbances resulting from pilot actions or system...
Topics: NASA Technical Reports Server (NTRS), AIRCRAFT RELIABILITY, CIVIL AVIATION, LIFT, REGULATIONS,...
Wind-tunnel tests were conducted on a baseline scramjet inlet model having fixed geometry and swept leading edges at M = 2.30, 2.96, 3.95, and 4.60 in the Langley unitary plan wind tunnel. The unit Reynolds number of the tests was held constant at 6.56 million per meter (2 million per foot). The objectives of the tests were to establish inlet performance and starting characteristics in the lower Mach number range of operation (less than M = 5). Surface pressures obtained on the inlet components...
Topics: NASA Technical Reports Server (NTRS), FLUID MECHANICS, INLET FLOW, INLET NOZZLES, SUPERSONIC...
A hierarchial, four level, standardized system for classifying land use/land cover primarily from remote-sensor data (USGS system) is described. The USGS system was developed for nonmicrowave imaging sensors such as camera systems and line scanners. The USGS system is not compatible with the land use/land cover classifications at different levels that can be made from radar imagery, and particularly from synthetic-aperture radar (SAR) imagery. The use of radar imagery for classifying land...
Topics: NASA Technical Reports Server (NTRS), CLASSIFICATIONS, LAND USE, MICROWAVE SENSORS, RADAR DATA,...
The design of a high efficiency, long life terrestrial module was completed. It utilized 256 rectangular, high efficiency solar cells to achieve high packing density and electrical output. Tooling for the fabrication of solar cells was in house and evaluation of the cell performance was begun. Based on the power output analysis, the goal of a 13% efficiency module was achievable.
Topics: NASA Technical Reports Server (NTRS), DESIGN ANALYSIS, ENERGY CONVERSION EFFICIENCY, PACKING...
The measurement of longitude of the Viking 1 landing site and the accuracy of the coordinates of features in the area around the landing site are discussed. The longitude must be measured photogrammatically from the small crater, Airy 0, which defines the 0 deg meridian on Mars. The computer program, GIANT, which was used to perform the analytical triangulations, and the photogrammetric computation of the longitude of the Viking 1 lander site are described. Improved coordinates of features in...
Topics: NASA Technical Reports Server (NTRS), COMPUTER PROGRAMS, MARS SURFACE, PHOTOGRAMMETRY, PLANETARY...
The influence of immobilization stress on spermiogenesis in rats was investigated. After 96 hour immobilization, histological changes began to manifest themselves in the form of practically complete disappearance of cell population of the wall of seminiferous tubule as well as a markedly increased number of cells with pathologic mitoses. Enzymological investigations showed various changes of activity (of acid and alkaline phosphatase and nonspecific esterase) in the 24, 48, and 96 hour...
Topics: NASA Technical Reports Server (NTRS), HYPOKINESIA, IMMOBILIZATION, PHYSIOLOGICAL EFFECTS,...
Progress in the correlation of MAGSAT anomaly maps with geological and geophysical data sets is reported. An excerpt from Bouguer gravity map of the U.S. was filtered to retain wavelengths of 250 km, thus being physically somewhat analogous to MAGSAT data at 400 km height. Residual anomalies were extracted to compare with the satellite magnetics.
Topics: NASA Technical Reports Server (NTRS), EARTH CRUST, MAGNETIC ANOMALIES, MAGNETIC SURVEYS, MINERAL...
Using digitally processed MSS/LANDSAT data as auxiliary variable, a methodology to estimate wheat (Triticum aestivum L) area by means of sampling techniques was developed. To perform this research, aerial photographs covering 720 sq km in Cruz Alta test site at the NW of Rio Grande do Sul State, were visually analyzed. LANDSAT digital data were analyzed using non-supervised and supervised classification algorithms; as post-processing the classification was submitted to spatial filtering. To...
Topics: NASA Technical Reports Server (NTRS), BRAZIL, CROP IDENTIFICATION, ESTIMATING, SAMPLING, WHEAT,...
The Cryogenic Fluid Management Experiment (CFME) was designed to characterize subcritical liquid hydrogen storage and expulsion in the low-g space environment. The CFME has now become the storage and supply tank for the Cryogenic Fluid Management Facility, which includes transfer line and receiver tanks, as well. The liquid hydrogen storage and supply vessel is supported within a vacuum jacket to two fiberglass/epoxy composite trunnions which were analyzed and designed. Analysis using the...
Topics: NASA Technical Reports Server (NTRS), CRYOGENIC FLUID STORAGE, FATIGUE (MATERIALS), LIQUID...
NASA Network Resource and Training Site
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An apparatus that is extremely effective in dispensing a wide range of droplets has been developed. This droplet dispenser is unique in that it utilizes a droplet bias voltage, as well as an ionization pulse, to release a droplet. Apparatuses that deploy individual droplets have been used in many applications, including, notably, study of combustion of liquid fuels. Experiments on isolated droplets are useful in that they enable the study of droplet phenomena under well-controlled and...
Topics: NASA Technical Reports Server (NTRS), DISPENSERS, DROPS (LIQUIDS), HIGH VOLTAGES, SYRINGES,...
A proposed method of detecting moving targets in scenes that include cluttered or noisy backgrounds is based on a soliton-resonance mathematical model. The model is derived from asymptotic solutions of the cubic Schroedinger equation for a one-dimensional system excited by a position-and-time-dependent externally applied potential. The cubic Schroedinger equation has general significance for time-dependent dispersive waves. It has been used to approximate several phenomena in classical as well...
Topics: NASA Technical Reports Server (NTRS), BOSE-EINSTEIN CONDENSATES, DETECTION, NONLINEAR OPTICS,...
The results of an evaluation of candidate metal-matrix composite materials for shuttle space radiators mounted to external structure are presented. The evaluation was specifically applicable to considerations of the manufacturing and properties of a potential space radiator. Two candidates, boron/aluminum and graphite/aluminum were obtained or made in various forms and tested in sufficient depth to allow selection of one of the two for future scale-up programs. The effort accomplished on this...
Topics: NASA Technical Reports Server (NTRS), METAL MATRIX COMPOSITES, SPACECRAFT COMPONENTS, SPACECRAFT...
The Tracking and Data Relay Satellite with a set of circularly-polarized, amplitude-sensing monopulse patterns suitable for acquiring and tracking user spacecraft at Ku-band (15.0 GHz) is discussed. The possibility of increasing the less than 0.4-degree half-power beamwidth of the data beam to almost 1.0 degree during the acquisition phase is predicated on the use of feeds situated in the first bright-ring of the Airy diffraction structure. A complex-vector simulation equivalent to the...
Topics: NASA Technical Reports Server (NTRS), MONOPULSE RADAR, TDR SATELLITES, DIFFRACTION, PATTERN...
Fe-36Ni is an alloy of choice for low thermal expansion coefficient (CTE) for optical, instrument and electrical applications in particular where dimensional stability is critical. This paper outlines the development of a particle-reinforced Fe-36Ni alloy that offers reduced density and lower CTE compared to the matrix alloy. A summary of processing capability will be given relating the composition and microstructure to mechanical and physical properties.
Topics: NASA Technical Reports Server (NTRS), THERMAL EXPANSION, DIMENSIONAL STABILITY, MECHANICAL...
An apparatus and method for measuring strain in an optical fiber using the spectral shift of Rayleigh scattered light. The interference pattern produced by an air gap reflector and backscattered radiation is measured. Using Fourier Transforms, the spectrum of any section of fiber can be extracted. Cross correlation with an unstrained measurement produces a correlation peak. The location of the correlation peak indicates the strain level in the selected portion of optical fiber.
Topics: NASA Technical Reports Server (NTRS), OPTICAL FIBERS, RAYLEIGH SCATTERING, STRAIN MEASUREMENT,...
A method and apparatus for disabling an echo canceller in a framed digital network from a remote terminal that is copuled to the network through an unframed data link. Control is effected by sending N different bit sequences from the remote terminal, where N is the number of different framing alignments that may be imposed on the unframed data by the network. The different sequences are chosen so that one will be framed by the network as the requisite control tone regardless of which framing...
Topics: NASA Technical Reports Server (NTRS), ECHO SUPPRESSORS, TELECOMMUNICATION, DATA LINKS, PATENTS,...
No abstract available
Topics: NASA Technical Reports Server (NTRS), SPACECRAFT LAUNCHING, SPACE EXPLORATION, LAUNCH VEHICLES, LOW...
Aircraft icing flight research was performed in natural icing conditions. A data base consisting of icing cloud measurements, ice shapes, and aerodynamic measurements is being developed. During research icing encounters the icing cloud was continuously measured. After the encounter, the ice accretion shapes on the wing were documented with a stereo camera system. The increase in wing section drag was measured with a wake survey probe. The overall aircraft performance loss in terms of lift and...
Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC CHARACTERISTICS, AIRCRAFT STRUCTURES, DRAG, ICE...
Experience has shown that the empirical Minnaert function is a very useful approximation to real photometric behavior near opposition (phase angle = 0), but that in general it cannot accurately model photometric scans across the face of even a homogeneous planet at higher phase angles. Given recent work on fitting the rigorous Hapke function to Voyager data for Io, we can test to what degree the Minnaert function breaks down in the case of Ionian materials by comparing photometric scans...
Topics: NASA Technical Reports Server (NTRS), ASTRONOMICAL PHOTOMETRY, IO, LIMB DARKENING, REFLECTANCE,...
The shuttle program took on the challenge of providing a manual landing capability for an operational vehicle returning from orbit. Some complex challenges were encountered in developing the longitudinal flying qualities required to land the orbiter manually in an operational environment. Approach and landing test flights indicated a tendency for pilot-induced oscillation near landing. Changes in the operational procedures reduced the difficulty of the landing task, and an adaptive stick filter...
Topics: NASA Technical Reports Server (NTRS), FLIGHT CHARACTERISTICS, MANUAL CONTROL, SPACE SHUTTLES,...
Before beginning this presentation, it is appropriate to acknowledge the sincere interest and financial support provided by the NASA LaRC under contract NAS9-17900. An outline of the material to be used in the present paper is given. It begins with a indication of the origin and objectives of the feasibility study. This is followed by a discussion of various simulation methods of establishing the persistence of shaped sonic boom signatures to large distances including the use of recoverable...
Topics: NASA Technical Reports Server (NTRS), FEASIBILITY, FIREBEE 2 TARGET DRONE AIRCRAFT, FLIGHT...
Topics: NASA Technical Reports Server (NTRS), TORQUE, TOOLS, PATENTS, Richards, Paul W. [Inventor]
Skutterudites have proven to be a useful thermoelectric system as a result of their high figure of merit, favorable mechanical properties, and good thermal stability. Binary skutterudites have received the majority of interest in recent years, as a result of successful double and triple filling schemes. Ternary skutterudites, such as Ni4Sb7Sn5, also demonstrate good thermoelectric performance, with high power factor and low thermal conductivity. Ternary skutterudites, as contrasted to binary...
Topics: NASA Technical Reports Server (NTRS), THERMOELECTRIC MATERIALS, TERNARY SYSTEMS, COMPOUNDING,...
The unique challenge of this concept to the structural designer is discussed. The potential of the application of advanced structural design concepts and new titanium fabrication processes is emphasized. Highlighted are the results of a detailed structural analysis, including weight and flutter, showing successful use of the ATLAS structural design and analysis system. It is concluded that blending of the structure may not have an adverse impact on structural efficiency, weight, and...
Topics: NASA Technical Reports Server (NTRS), STRUCTURAL DESIGN, SUPERSONIC AIRCRAFT, TITANIUM ALLOYS,...
There are no author-identified significant results in this report.
Topics: NASA Technical Reports Server (NTRS), COLORADO, DATA PROCESSING, FORESTS, IMAGE PROCESSING,...
Computer aided tomography (CAT) provides a means of noninvasively measuring the air density distribution around an aerodynamic model. This technique is global in that a large portion of the flow field can be measured. A test of the applicability of CAT to transonic velocities was studied. A hemispherical-nose cylinder afterbody model was tested at a Mach number of 0.8 with a new laser holographic interferometer at the 2- by 2-Foot Transonic Wind Tunnel. Holograms of the flow field were taken...
Topics: NASA Technical Reports Server (NTRS), AERODYNAMICS, ATMOSPHERIC DENSITY, COMPUTER AIDED TOMOGRAPHY,...
Tests were conducted on hydrofoil assemblies approximating an arrangement for use under seaplanes or surface boats. A series of hydrofoils, each supported by two struts, was towed at various depths ranging from partial submersions to a depth of 5-chord lengths. At depths greater than 4 or 5 chords, the influence of the surface of the water is small; hydrofoils operating at low speed will have characteristics similar to those of airfoils of the same section.
Topic: NASA Technical Reports Server (NTRS)
NASA is studying the effects of long-term space radiation on potential multifunctional composite materials for habitats to better determine their characteristics in the harsh space environment. Two composite materials were selected for the study and were placed in a test stand that simulated the stresses of a pressure vessel wall on the material. The samples in the test stand were exposed to radiation at either a fast dose rate or a slow dose rate, and their strain and temperature was recorded...
Topics: NASA Technical Reports Server (NTRS), COMPOSITE MATERIALS, EXTRATERRESTRIAL RADIATION, LUNAR...
A continuing challenge for modern instrument pointing control systems is to meet the increasingly stringent pointing performance requirements imposed by emerging advanced scientific, defense, and civilian payloads. Instruments such as adaptive optics telescopes, space interferometers, and optical communications make unprecedented demands on precision pointing capabilities. A cost-effective method was developed for increasing the pointing performance for this class of NASA applications. The...
Topics: NASA Technical Reports Server (NTRS), ANGULAR VELOCITY, ATTITUDE (INCLINATION), POINTING CONTROL...
The concept to place electric power generating stations on the oceans off the coast of the United States has instilled new efforts in research for improved understanding of the diffusion properties of the atmosphere in the ocean-air interface. The Atomic Energy Commission has instigated a program by the Meteorology Group at Brookhaven National Laboratory to investigate the low level, on-shore wind systems that dominate many of the coastal regions. Analytical techniques and specialized...
Topics: NASA Technical Reports Server (NTRS), OPTICAL RADAR, ELECTRIC POWER, ELECTRIC GENERATORS, OCEANS,...
Longitudinal aerodynamic characteristics of two full-scale helicopter fuselage models
Topic: NASA Technical Reports Server (NTRS)
Static pressure & stagnation pressure calibration data for defining position errors of airspeed- altitude systems of x-15 aircraft
Topic: NASA Technical Reports Server (NTRS)
Encapsulation technique minimizes embedment and thermal stresses in welded electronic modules. A coating of thinned room-temperature- vulcanizing silicone rubber having a high coefficient of expansion and flexibility at low temperature, is applied first and then an encapsulating epoxy resin having a relatively low coefficient of expansion is added.
Topic: NASA Technical Reports Server (NTRS)
Time synchronization of remote station clocks
Topic: NASA Technical Reports Server (NTRS)
Damping of piezoelectric quartz crystal driven in torsional mode of vibration in liquid helium 3 and helium 4
Topic: NASA Technical Reports Server (NTRS)
Ektachrome and Ektachrome infrared aerial photography of Twin Buttes area, Arizona
Topic: NASA Technical Reports Server (NTRS)
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Inverter drive circuit for semiconductor switch
Topic: NASA Technical Reports Server (NTRS)
There are no author-identified significant results in this report.
Topics: NASA Technical Reports Server (NTRS), FORESTS, TIMBER INVENTORY, VIRGINIA, EARTH RESOURCES PROGRAM,...
An experimental oxide dispersion strengthened (ODS) alloy, WAZ-D, derived from the WAZ-20 composition was produced by the mechanical alloying process. Cast WAZ-20 is strengthened by both a high refractory metal content, and 70 volume percent of gamma prime. The ODS alloy WAZ-D was responsive to variables of alloy content, of attritor processing, of consolidation by extrusion, and of heat treatment. The best material produced had large highly elongated grains. It exhibited tensile strengths...
Topics: NASA Technical Reports Server (NTRS), ALUMINUM ALLOYS, METAL OXIDES, NICKEL ALLOYS, OXIDE...
Numerical solutions of the viscous shock layer equations governing laminar and turbulent flows of a perfect gas and radiating and nonradiating mixtures of perfect gases in chemical equilibrium are presented for hypersonic flow over spherically blunted cones and hyperboloids. Turbulent properties are described in terms of the classical mixing length. Results are compared with boundary layer and inviscid flowfield solutions; agreement with inviscid flowfield data is satisfactory. Agreement with...
Topics: NASA Technical Reports Server (NTRS), BLUNT BODIES, HYPERSONIC FLOW, SHOCK LAYERS, VORTICES,...
A laboratory gas analysis system was developed specifically to make trace level measurements of carbon monoxide. To assure that the data collected with this system are correctly aligned with other established methods for making these measurements, an intercalibration study was conducted. The calibration gas was analyzed by the various participating laboratories and found to contain 1.28 ppm CO. Samples were collected at 25 deg, 35 deg, and 45 deg N for profile data to study the variation in...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC COMPOSITION, GAS CHROMATOGRAPHY, REMOTE SENSORS,...
There are no author-identified significant results in this report.
Topics: NASA Technical Reports Server (NTRS), ANDESITE, BARITE, GEOLOGICAL SURVEYS, HEAT CAPACITY MAPPING...
A simplified mathematical model was developed which predicts the optical propagation losses which occur when an optical beam of given wave length passes through a turbulent boundary layer or shear layer. The optical losses are predicted in terms of line spread function (or Strehl ratio) and modulation transfer function by using experimentally determined values of layer thickness, streamwise, lateral and beamwise density fluctuation length scales, and distribution of the standard deviation of...
Topics: NASA Technical Reports Server (NTRS), MATHEMATICAL MODELS, SHEAR LAYERS, TURBULENT BOUNDARY LAYER,...
Tests with cardioleader to control the physical, technical and tactical preparedness of athletes in cyclic types of sports are discussed. Ways of increasing the reliability and information content of the tests were studied.
Topics: NASA Technical Reports Server (NTRS), BIOENGINEERING, BIOMEDICAL DATA, BIOMETRICS, HUMAN...
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Inert gas thrusters considered for space propulsion systems were investigated. Electron diffusion across a magnetic field was examined utilizing a basic model. The production of doubly charged ions was correlated using only overall performance parameters. The use of this correlation is therefore possible in the design stage of large gas thrusters, where detailed plasma properties are not available. Argon hollow cathode performance was investigated over a range of emission currents, with the...
Topics: NASA Technical Reports Server (NTRS), ION PROPULSION, PLASMA PROPULSION, RARE GASES, ROCKET ENGINE...
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The long term discharge of a variety of lithium cells was characterized and the susceptibility of the cells to chemical variation during the slow discharge was tested. A shunt resistor was set across the terminals to monitor the voltage as a function of time. Failures were identified by premature voltage drops.
Topics: NASA Technical Reports Server (NTRS), ELECTRIC DISCHARGES, ENERGY TECHNOLOGY, LITHIUM COMPOUNDS,...
Metal 4, 4', 4"",-tetracarboxylic phthalocyanines (MPTC) are prepared by reaction of trimellitic anhydride, a salt or hydroxide of the desired metal (or the metal in powdered form), urea and a catalyst. A purer form of MPTC is prepared than heretofore. These tetracarboxylic acids are then polymerized by heat to sheet polymers which have superior heat and oxidation resistance. The metal is preferably a divalent metal having an atomic radius close to 1.35A.
Topics: NASA Technical Reports Server (NTRS), CARBOXYLIC ACIDS, METALS, PHTHALOCYANIN, POLYMERIC FILMS,...
A combined U-Th-Pb and Lu-Hf isotopic study of zircons was undertaken in order to determine the provenance and age of an Archean granite-greenstone terrain and to test the detailed application of the Lu-Hf system in various Archean zircons. The eastern Wawa subprovince of the Superior province consists of the low grade Michipicoten and Gamitagama greenstone belts and the granitic terrain. The Hf isotopic data indicate that the typical lithological features of a greenstone belt cycle could be...
Topics: NASA Technical Reports Server (NTRS), EARTH CRUST, EARTH MANTLE, GEOCHRONOLOGY, STRUCTURAL...
A thin film device was designed and fabricated to measure surface temperatures. An array of eight integrated thermal sensors are mounted on a 0.002 inch (0.05 mm) Kapton film and multiplexed to obtain an area thermal measurement. The device was tested on a flat plate airfoil and demonstrated a temperature variation of 0.55 C maximum and 0.05 C minimum compared to embedded thermocouples. Future improvements are also discussed.
Topics: NASA Technical Reports Server (NTRS), AIRFOILS, ARRAYS, FUNCTIONAL DESIGN SPECIFICATIONS,...
A study of intelligent guidance and control concepts for protecting against the adverse effects of wind shear during aircraft takeoffs and landings is being conducted, with current emphasis on developing an expert system for wind shear avoidance. Principal objectives are to develop methods for assessing the likelihood of wind shear encounter (based on real-time information in the cockpit), for deciding what flight path to pursue (e.g., takeoff abort, landing go-around, or normal climbout or...
Topics: NASA Technical Reports Server (NTRS), CONTROL THEORY, EXPERT SYSTEMS, FLIGHT CONTROL, WIND SHEAR,...
Kinematic sensitivity vectors and matrices for open-loop, n degrees-of-freedom manipulators are derived. First-order sensitivity vectors are defined as partial derivatives of the manipulator's position and orientation with respect to its geometrical parameters. The four-parameter kinematic model is considered, as well as the five-parameter model in case of nominally parallel joint axes. Sensitivity vectors are expressed in terms of coordinate axes of manipulator frames. Second-order sensitivity...
Topics: NASA Technical Reports Server (NTRS), KINEMATICS, MANIPULATORS, ROBOT ARMS, ROBOT DYNAMICS,...
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An improved fluid actuating system for imparting motion to a body such as a spacecraft is disclosed. The fluid actuating system consists of a fluid mass that may be controllably accelerated through at least one fluid path whereby an opposite acceleration is experienced by the spacecraft. For full control of the spacecraft's orientation, the system would include a plurality of fluid paths. The fluid paths may be circular or irregular, and the fluid paths may be located on the interior or...
Topics: NASA Technical Reports Server (NTRS), ACTUATORS, ATTITUDE CONTROL, FLUIDS, MOMENTUM TRANSFER,...
Topic: NASA Technical Reports Server (NTRS)
Report discusses the theory of energy losses in wind tunnels, the application of the Drzewiecki theory of propeller design to wind tunnel propellers, and the efficiency and steadiness of flow in model tunnels of various types.
Topic: NASA Technical Reports Server (NTRS)
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This work on accelerometry was done at McCook Field for the purpose of continuing the work done by
Topic: NASA Technical Reports Server (NTRS)
The factors which affect the extent of laminar flow on airplanes for hypersonic flight are discussed on the basis of the available data. Factors considered include flight Reynolds number, surface roughness, angle of attack, angle of leading-edge sweepback, and aerodynamic interference. Test data are presented for one complete configuration.
Topic: NASA Technical Reports Server (NTRS)
A knowledge of the quasi-steady acceleration environment on the NASA Space Shuttle Orbiter is of particular importance for materials processing experiments which are limited by slow diffusive processes. The quasi-steady (less than 1 HZ) acceleration environment on STS-73 (USML-2) was measured using the Orbital Acceleration Research Experiment (OARE) accelerometer. One of the facilities flown on USML-2 was the Crystal Growth Furnace (CGF), which was used by several Principal Investigators (PIS)...
Topics: NASA Technical Reports Server (NTRS), SPACE SHUTTLE ORBITERS, ATTITUDE (INCLINATION),...
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This report details work performed by the Center for Applied Optics (CAO) at the University of Alabama in Huntsville (UAH) on the contract entitled 'Atomic Oxygen Task' for NASA's Marshall Space Flight Center (contract NAS8-38609, Delivery Order 109, modification number 1). Atomic oxygen effects on exposed materials remain a critical concern in designing spacecraft to withstand exposure in the Low Earth Orbit (LEO) environment. The basic objective of atomic oxygen research in NASA's Materials...
Topics: NASA Technical Reports Server (NTRS), OXYGEN ATOMS, AIRCRAFT DESIGN, EXPOSURE, ENVIRONMENT EFFECTS,...
Goddard High Resolution Spectrograph (GHRS) observations have revealed the presence of broad wings in the transition-region lines of AU Mic and Capella. It has been proposed that these wings are signatures of microflares in the transition regions of these stars and that the solar analog for this phenomenon might be the 'transition region explosive events' discussed by Dere, Bartoe, & Brueckner. We have analyzed GHRS observations of Procyon (F5 IV-V) and HR 1099 (K1 IV + G5 IV) to search for...
Topics: NASA Technical Reports Server (NTRS), STAR FORMATION, CHROMOSPHERE, EMISSION SPECTRA, LINE SPECTRA,...
Monitoring observations with interval of 3 days using RXTE (X Ray Timing Explorer) of the luminous Seyfert 1 galaxy Fairall 9 were performed for one year. The purpose of the observations were to study the variability of Fairall 9 and compare the results with those from the radio-loud object 3C 390.3. The data has been received and analysis is underway, using the new background model. An observation of the quasar MR 2251-178 was made in order to determine whether or not it has a reflection...
Topics: NASA Technical Reports Server (NTRS), SEYFERT GALAXIES, INFRARED RADIATION, INFRARED SPECTRA, X RAY...
The effects of pion (PI) production are expected to play an important role in radiation exposures in the upper atmosphere or on the Martian surface. Nuclear databases for describing pion production are developed for radiation transport codes to support these studies. We analyze the secondary energy spectrum of pions produced in nucleon-nucleon (NN) collisions in the relativistic one-pion exchange model. Parametric formulas of the isospin cross sections for one-pion production channels are...
Topics: NASA Technical Reports Server (NTRS), NUCLEON-NUCLEON INTERACTIONS, PIONS, RADIATION TRANSPORT,...
Pressure broadening and pressure-induced shift coefficients due to water and nitrogen have been determined for water vapor transitions in the CO2 region of interest to Project HALOE. The temperature dependences of the widths and shifts have also been determined for selected transitions in this region. Results have been compared with values available in the literature. The line parameters have been obtained from the analysis of room temperature recordings of the spectrum of pure water and...
Topics: NASA Technical Reports Server (NTRS), SPECTRAL LINE WIDTH, INFRARED SPECTRA, WATER VAPOR, CARBON...
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The line integral convolution (LIC) technique has been known to be an effective tool for depicting flow patterns in a given vector field. There have been many extensions to make it run faster and reveal useful flow information such as velocity magnitude, motion, and direction. There are also extensions to unsteady flows and 3D vector fields. Surprisingly, none of these extensions automatically highlight flow features, which often represent the most important and interesting physical flow...
Topics: NASA Technical Reports Server (NTRS), FLOW DISTRIBUTION, UNSTEADY FLOW, PHYSICAL FACTORS, SADDLE...
The fatigue crack growth rate of aluminum-lithium (Al-Li) alloy 2195 plate and weldments was determined at 200-F, ambient temperature and -320-F. The effects of stress ratio (R), welding process, orientation and thickness were studied. Results are compared with plate data from the Space Shuttle Super Lightweight Tank (SLWT) allowables program. Data from the current series of tests, both plate and weldment, falls within the range of data generated during the SLWT allowables program.
Topics: NASA Technical Reports Server (NTRS), ALUMINUM-LITHIUM ALLOYS, CRACK PROPAGATION, WELDED JOINTS,...
This paper presents viewgraphs of the RS-68 and Linear Aerospike engines. The topics include: 1) The mission; 2) Design and Development Strategies; 3) Cost Driven Design Trades; 4) Moderate Pressure Requirements Enable Reduced Complexity; 5) Experience Based Design; 6) Development Costs Dominated by Cost of Eliminating Failure Modes; and 7) Reducing Development Costs. This paper also includes the design of the RS-68 Engine and the engine performance.
Topics: NASA Technical Reports Server (NTRS), AEROSPIKE ENGINES, LIQUID PROPELLANT ROCKET ENGINES, DESIGN...