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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 397 records · Page 22
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Remote sensing and water resources - U.S. Space Program

Since the launch of TIROS I in 1960, the utility of remote sensing from orbit for monitoring the earth's weather has been conclusively demonstrated. The past decade has also seen progress in applying remote sensing to the observation of terrestrial features. Variations in snow and ice cover, surface water, river and lake turbidity, and other hydrological features are now being accurately observed from orbital altitudes by the Earth Resources Technology Satellite (ERTS-1), NOAA-2, and Nimbus 5. Satellite visible, infrared and microwave measurements will be continued over the next few years, with improved spatial and spectral accuracy, by Skylab, ERTS-B, and Nimbus F. Delineations of soil and snow moisture variations, thermal patterns in lakes and estuaries, and regions of heavy precipitation are among the results anticipated.

Molloy, M. W.↗
NASA NTRS1974

Reliability analysis of Skylab ATM solar cell modules

A detailed reliability analysis was performed on both types of Skylab Apollo telescope mount solar cell modules. Failure rates used were based on testing of several modules of each type for over 4000 thermal cycles. The analysis delineated several important differences between the failure modes of the two differently designed solar cell modules, and, more importantly, showed that the modules can be expected to meet all mission requirements.

Jones, G. M.↗
NASA NTRS1974

Experimental and analytical studies in tilt-rotor aeroelasticity

An overview of an experimental and analytical research program for studying the aeroelastic and dynamic characteristics of tilt-rotor VTOL aircraft is presented. Selected results from several investigations of scaled models in the Langley transonic dynamics tunnel as well as some results from a test of a flight-worthy prop rotor in the NASA Ames full-scale wind tunnel are shown and discussed with a view toward delineating various aspects of dynamic behavior peculiar to prop rotor aircraft. Included are such items as prop rotor pylon stability, whirl flutter, gust response, and blade flapping. Theoretical predictions, based on analyses developed at Langley, are shown to be in agreement with the measured stability and response behavior.

Kvaternik, R. G.↗
NASA NTRS1974

The polyuria of paroxysmal atrial tachycardia

Two patients with paroxysmal atrial fibrillation and an associated polyuria were studied to delineate the mechanism of the increase in urine flow. A striking saluresis was noted in both patients. The increased sodium excretion was probably due to decreased sodium reabsorption, perhaps at proximal tubular nephron sites. This inhibition of sodium reabsorption could explain both the saluresis and some part or all of the polyuria. Re-evaluation of earlier case reports reveals patterns of concomitant salt and water excretion consistent with this mechanism. The saluresis cannot be explained by the previously favored hypothesis of antidiuretic hormone inhibition.

Kinney, M. J.↗
NASA NTRS1974

ERTS-1 imagery interpretation techniques in the Tennessee Valley

The author has identified the following significant results. The feasibility of delineating major soil associations and land uses through computerized analyses is discussed. Useful and potential applications in detecting landscape change and land use mapping are described. Recommendations for improving the data processing effort in a multidisciplinary program are presented.

Bodenheimer, R. E.↗
NASA NTRS1974

Geologic evaluation and applications of ERTS-1 imagery over Georgia

Satellite imagery and other remote sensing tools and techniques have provided a powerful tool to assist geologic research; significantly increased the mapping efficiency of field geologists; shown new lineaments associated with known shear and fault zones; delineated new structural features; provided a tool to reevaluate tectonic history; helped to locate potential ground-water sources and areas of aquifer recharge; defined areas of geologic hazards; shown areas of heavy siltation in major reservoirs; and, by close interval repetition, aided in monitoring surface mine reclamation activities and the environmental protection of the intricate marshland system. The Georgia Geological Survey has been engaged in regional mapping for the new state geologic map. ERTS-1 images enlarged to compatible mapping scales have increased field geologic mapping efficiency by at least 25%. There are a number of areas where data from ERTS-1 imagery has allowed a notably higher level of precision than has been available with any amount of field work on the ground.

Pickering, S. M.↗
NASA NTRS1974

Remote sensing applications in marine science programs at VIMS

Scientists at the Virginia Institute of Marine Science (VIMS) utilized remote sensing in three programs: (1) tonal variations in imagery of wetlands; (2) use of the thermal infrared to delineate the discharge cooling water at the Virginia Electric and Power Company (VEPCO) nuclear power station on the James River; and (3) the use of aerial photography to determine the volume storage function for water in the marsh-bay complex fed by Wachapreague Inlet on the Eastern Shore of Virginia. Details of the investigations are given, along with significant results.

Gordon, H. H.↗
NASA NTRS1974

Zero-Gravity Atmospheric Cloud Physics Experiment Laboratory engineering concepts/design tradeoffs. Volume 1: Study results

The work is summarized which was accomplished from January 1974 to October 1974 for the Zero-Gravity Atmospheric Cloud Physics Laboratory. The definition and development of an atmospheric cloud physics laboratory and the selection and delineation of candidate experiments that require the unique environment of zero gravity or near zero gravity are reported. The experiment program and the laboratory concept for a Spacelab payload to perform cloud microphysics research are defined. This multimission laboratory is planned to be available to the entire scientific community to utilize in furthering the basic understanding of cloud microphysical processes and phenomenon, thereby contributing to improved weather prediction and ultimately to provide beneficial weather control and modification.

Greco, R. V.↗
NASA NTRS1972

Ocean color, a three component system?

This study measures the concentrations of phytoplankton chlorophyll and yellow substance in the coastal waters of the Gulf of Maine. Sea surface observations attempt to delineate the principal biochemical parameters responsible for sea surface color. It is shown that the reddish-brown water changed to a blue-green in the open gulf.

Yentsch, C. S.↗
NASA NTRS1974

Evaluation of satellite remote sensing and automatic data techniques for characterization of wetlands and coastal marshlands

The author has identified the following significant results. ERTS digital data has been used to detect and measure accretion in the large estuarial system of the Atchafalaya River in southern Louisiana. Comparisons of aerial photography taken in October 1970 with a computer printout of ERTS digital data collected on October 1, 1972, show that in a delineated area of 1400 hectares (3460 acres) an accretion of land area in the amount of 112 hectares (277 acres) had occurred. Analysis of band 3 of the ERTS MSS was used to make a land-water map of the area. The accretion test area was marked on this map and the percentage of elements indicated as land was calculated. This percentage was then multiplied by the total test area to obtain the area of land on the date of the ERTS observation for comparison with the aerial photography. Significant improvement in classification accuracy of ERTS MSS data has been achieved by use of a priori probabilities of occurrence in pattern recognition programs. Two classifications were made with accuracies of 76.0% and 81.5%, respectively.

Cartmill, R. H.↗
NASA NTRS1974

Acceleration processes in the quasi-steady magnetoplasmadynamic discharge

The flow field characteristics within the discharge chamber and exhaust of a quasi-steady magnetoplasmadynamic (MPD) arcjet were examined to clarify the nature of the plasma acceleration process. The observation of discharge characteristics unperturbed by insulator ablation and terminal voltage fluctuations, first requires the satisfaction of three criteria: the use of refractory insulator materials; a mass injection geometry tailored to provide propellant to both electrode regions of the discharge; and a cathode of sufficient surface area to permit nominal MPD arcjet operation for given combinations of arc current and total mass flow. The axial velocity profile and electromagnetic discharge structure were measured for an arcjet configuration which functions nominally at 15.3 kA and 6 g/sec argon mass flow. An empirical two-flow plasma acceleration model is advanced which delineates inner and outer flow regions and accounts for the observed velocity profile and calculated thrust of the accelerator.

Boyle, M. J.↗
NASA NTRS1974

Cytogenic studies of blood (experiment M111)

The Skylab M111 experiment was a continuation of the preflight and postflight chromosomal analyses of the flight crews that have been performed since the Gemini 3 mission. The experiment was designed to determine whether some space flight parameter produces cytogenetic effects in human cells and to provide biological radiation dosimetric capability in the event of significant radiation exposure to a flight crew. On each of the Skylab flights, blood lymphocytes for analysis of chromosomes for structural defects were obtained from each of the prime crewmembers and from a ground-based control group before and after flight. Two types of defects were recorded. The minor defects included the following aberrations: chromatid fragments, chromosome fragments, and deletions. Structural rearrangements such as dicentrics, exchanges, ring chromosomes, and translocations were photographed, and the cells were karyotyped to delineate, when possible, the chromosome or chromosomes involved in the rearrangement. Result seems to indicate that the flight itself was not a major contributing factor.

Lockhart, L. H.↗
NASA NTRS1974

A demonstration of ERTS-1 analog and digital techniques applied to strip mining in Maryland and West Virginia

The largest contour strip mining operations in western Maryland and West Virginia are located within the Georges Creek and the Upper Potomac Basins. These two coal basins lie within the Georges Creek (Wellersburg) syncline. The disturbed strip mine areas were delineated with the surrounding geological and vegetation features using ERTS-1 data in both analog (imagery) and digital form. The two digital systems used were: (1) the ERTS-Analysis system, a point-by-point digital analysis of spectral signatures based on known spectral values, and (2) the LARS Automatic Data Processing System. The digital techniques being developed will later be incorporated into a data base for land use planning. These two systems aided in efforts to determine the extent and state of strip mining in this region. Aircraft data, ground verification information, and geological field studies also aided in the application of ERTS-1 imagery to perform an integrated analysis that assessed the adverse effects of strip mining. The results indicated that ERTS can both monitor and map the extent of strip mining to determine immediately the acreage affected and indicate where future reclamation and revegetation may be necessary.

Anderson, A. T.↗
NASA NTRS1974

Radiation measurements from polar and geosynchronous satellites

Nimbus 5 satellite data and its use to study climate and develop climate model experiments are examined. Data cover: (1) physical basis for understanding long range and climate monitoring and prediction problem, (2) delineating energy loss to space between contributions from land, ocean, and atmosphere, (3) temporal and spatial distribution in earth's energy budget and its variations due to global cloud fields, and (4) studies of the frequency of occurrence of precipitation over ocean areas.

Vonderhaar, T. H.↗
NASA NTRS1975

Earth and ocean physics

A procedure for obtaining a parameterization of the marine geoid for suitable orthogonality properties in altimetry data is discussed. The application of the technique to the Puerto Rico trench is explained and a map of the data is developed. The Goddard Earth Model (GEM-6) is described to show the method for determining the earth gravity field using data obtained from satellite tracking stations. The derivation of a global ocean tide model from satellite data is explained. The influence of solid earth and ocean tides on the inclination of GEOS-1 is plotted. The delineation of the geographical fracture pattern and boundary system of the tectonic plates using ERTS satellite is shown.

Source record↗
NASA NTRS1974

Geology of the Sklodowska Region, Lunar Farside

Investigation of an area on the lunar farside has resulted in a geologic map, development of a regional stratigraphic sequence, and interpretation of surface materials. Apollo 15 metric photographs were used in conjunction with photogrammetric techniques to produce a base map to which geologic units were later added. Geologic units were first delineated on the metric photographs and then transferred to the base map. Materials were defined and described from selected Lunar Orbiter and Apollo 15 metric, panoramic, and Hasselblad photographs on the basis of distinctive morphologic characteristics.

Kauffman, J. D.↗
NASA NTRS1975

Flight control systems properties and problems, volume 1

This volume contains a delineation of fundamental and mechanization-specific flight control characteristics and problems gleaned from many sources and spanning a period of over two decades. It is organized to present and discuss first some fundamental, generic problems of closed-loop flight control systems involving numerator characteristics (quadratic dipoles, non-minimum phase roots, and intentionally introduced zeros). Next the principal elements of the largely mechanical primary flight control system are reviewed with particular emphasis on the influence of nonlinearities. The characteristics and problems of augmentation (damping, stability, and feel) system mechanizations are then dealt with. The particular idiosyncracies of automatic control actuation and command augmentation schemes are stressed, because they constitute the major interfaces with the primary flight control system and an often highly variable vehicle response.

Mcruer, D. T.↗
NASA NTRS1975

A multisensor analysis of Nimbus-5 data recorded on 22 January 1973

The Nimbus 5 meteorological satellite has a full complement of radiation sensors. Data from these sensors were analyzed and intercompared for orbits 569 and 570. The electrically-scanning microwave radiometer (19.35-GHz region) delineated rain areas over the ocean off the U.S. east coast, in good agreement with radar imagery, and permitted the estimation of rainfall rates in this region. Residual ground water, from abnormal rainfall in the lower Mississippi Valley, was indicated under clear sky conditions by soil brightness temperature values in the Nimbus 5 electrically scanning microwave radiometer and U.S. Air Force Data Acquisition and Processing Program infrared data. The temperature-humidity infrared radiometer (6.7 micron and 11 micron) showed the height and spatial configuration of frontal clouds along the east coast and outlined the confluence of a polar jet stream with a broad subtropical jet stream along the U.S. Gulf Coast. Temperature profiles from three vertical temperature sounders are found to be in good agreement with related radiosonde ascents along orbit 569 from the subtropics to the Arctic Circle.

Allison, L. J.↗