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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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Acoustic emission produced during burst tests of filament-wound bottles.

Acoustic emission was recorded during burst tests of filament-wound, composite pressure vessels. Organic and graphite fibers were tested, and two different epoxy resin systems were used: one with a low and another with a relatively high cure temperature. Acoustic emission was studied for the effects of different winding patterns, artificial flaws, winding-induced fiber fraying, different resins, and different fibers. Small effects produced in the vessels by changes in these variables were greatly magnified when they appeared as changes in acoustic emission. They would, in fact, be difficult or impossible to detect by other test means.

Hamstad, M. A.↗
NASA NTRS1974

Land use mapping and modelling for the Phoenix Quadrangle

The author has identified the following significant results. Changes in the land use in the Phoenix (1:250,000 scale) Quadrangle in Arizona have been mapped using only the images from ERTS-1, tending to verify the utility of a land use classification system proposed for use with ERTS images. Seasonal changes were studied on successive ERTS-1 images, particularly large scale color composite transparencies for August, October, February, and May, and this seasonal variation aided delineation of land use boundaries. Types of equipment used to aid interpretation included color additive viewer, a twenty-power magnifier, a density slicer, and a diazo copy machine. A Zoom Transfer Scope was used for scale and photogrammetric adjustments. Types of changes detected have been: (1) cropland or rangeland developed as new residential areas; (2) rangeland converted to new cropland or to new reservoirs; and (3) possibly new activity by the mining industries. A map of land use previously compiled from air photos was updated in this manner. ERTS-1 images complemented air photos: the photos gave detail on a one-shot basis; the ERTS-1 images provided currency and revealed seasonal variation in vegetation which aided interpretation of land use.

Place, J. L.↗
NASA NTRS1974

Optical analysis of a compound quasi-microscope for planetary landers

A quasi-microscope concept, consisting of facsimile camera augmented with an auxiliary lens as a magnifier, was introduced and analyzed. The performance achievable with this concept was primarily limited by a trade-off between resolution and object field; this approach leads to a limiting resolution of 20 microns when used with the Viking lander camera (which has an angular resolution of 0.04 deg). An optical system is analyzed which includes a field lens between camera and auxiliary lens to overcome this limitation. It is found that this system, referred to as a compound quasi-microscope, can provide improved resolution (to about 2 microns ) and a larger object field. However, this improvement is at the expense of increased complexity, special camera design requirements, and tighter tolerances on the distances between optical components.

Wall, S. D.↗
NASA NTRS1974

Evaluate ERTS imagery for mapping and detection of changes of snowcover on land and on glaciers

The author has identified the following significant results. Snowlines on a small drainage basin were accurately identified on bulk ERTS-1 images without use of digital processing, and results checked with high altitude and ground-based photography. The area and approximate shape of snow patches as small as 20,000 sq m could be correctly identified with a magnifying scanning densitometer. The resolution of ERTS is more than ample for most snow mapping needs. Mount Baker, Washington, has a large crater south of the summit and an area north of the summit which emit considerable geothermal heat in the form of fumaroles and hot ground. Temperatures are being monitored using an ERTS DCS. Debris flows are occassionally released from the crater due to water saturation at the base of a heavy snowpack lying on hydrothermally altered hot ground. These debris flows present a possible hazard to life and property, as they are discharged down the Boulder Glacier toward Baker Lake, the upper of two major hydroelectric power reservoirs which are situated above the populated Skagit River Valley. ERTS-1 images show that the most recent debris flow (20-21 August 1973) can be clearly discerned and mapped. ERTS images provide another important tool for monitoring this potential hazard.

Meier, M. F.↗
NASA NTRS1974

MSFC engineering support to Skylab operations

Major engineering support provided during the Skylab mission from the Marshall Space Flight Center and its contractors to the Mission Control Center at Houston was essential to Skylab success. The need for this type of support was anticipated during premission preparations due to the complexity and first-flight nature of the Skylab, but the requirements were greatly magnified by the problems encountered early in the mission. The MFSC engineering support organization and its interface to the Mission Control Center is described. The importance of close cooperation between the operating and engineering organizations in this type of mission is discussed. Illustrations are given from more than 1800 systems analysis actions worked out during the nine-month Skylab mission by more than 600 support engineers.

Kurtz, H. F., Jr.↗
NASA NTRS1974

Analysis for Mar Vel Black and acetylene soot low reflectivity surfaces for star tracker sunshade applications

Mar Vel Black is a revolutionary new extremely low reflectivity anodized coating developed by Martin Marietta of Denver. It is of great interest in optics in general, and in star trackers specifically because it can reduce extraneous light reflections. A sample of Mar Vel Black was evaluated. Mar Vel Black looks much like a super black surface with many small peaks and very steep sides so that any light incident upon the surface will tend to reflect many times before exiting that surface. Even a high reflectivity surface would thus appear to have a very low reflectivity under such conditions. Conversely, acetylene soot does not have the magnified surface appearance of a super black surface. Its performance is, however, predictable from the surface structure, considering the known configuration of virtually pure carbon.

Yung, E.↗
NASA NTRS1975

Design and fabrication of composite wing panels containing a production splice

Bolted specimens representative of both upper and lower wing surface splices of a transport aircraft were designed and manufactured for static and random load tension and compression fatigue testing including ground-air-ground load reversals. The specimens were fabricated with graphite-epoxy composite material. Multiple tests were conducted at various load levels and the results were used as input to a statistical wearout model. The statically designed specimens performed very well under highly magnified fatigue loadings. Two large panels, one tension and compression, were fabricated for testing by NASA-LRC.

Reed, D. L.↗
NASA NTRS1974

HiMAT - A new approach to the design of highly maneuverable aircraft

Needed improvements in the maneuvering performance of combat aircraft appear to be possible through the simultaneous application of advances in various disciplines in such a way that they complement one another and magnify the benefits derived. The highly maneuverable aircraft technology (HiMAT) program is being conducted to investigate such multidisciplinary concepts. The program has three phases: preliminary studies, conceptual design studies, and the final design and construction of a test airplane. Work is now in the second phase. The test airplane will be a scaled model flown by a remotely piloted research vehicle technique. This paper outlines the HiMAT program and indicates the types of concepts being considered.

Bellman, D. R.↗
NASA NTRS1975

X-ray method shows fibers fail during fatigue of boron-epoxy laminates

A method proposed for studying progressive fiber fracture in boron-epoxy laminates during fatigue tests is described. It is based on the intensity of X-ray absorption of the tungsten core in the boron filaments as contrasted with that of the boron and epoxy matrix. When the laminate is X-rayed, the image of the tungsten in the born filaments is recorded on a photographic plate. Breaks in the boron laminates can be easily identified by magnifying the photographic plates. The method is suitable for studying broken boron filaments in most matrix materials, and may supply key information for developing realistic fatigue and fracture models.

Roderick, G. L.↗
NASA NTRS1977

Method for fabricating a mass spectrometer inlet leak

A method of fabricating an inlet leak for measuring chemically reactive gases is proposed. The method involves the steps of preparing a selected internal surface of a high melting point metal tubing for sealing to a glass tubing. A portion of the glass tubing is inserted into the prepared portion of the metal tubing, the glass tubing having an outer diameter substantially the same as the inner diameter of the metal tubing. The inserted glass tubing is sealed to the internal surface of the metal tubing; the glass tubing is drawn under a magnifying device to reduce the entire interior diameter thereof to substantially two microns; and an end portion of the drawing glass tubing is broken away.

Harris, R. F.↗
NASA NTRS1978

Portable fluorescent-dye inspection device

Hand-held device blocks ambient light from inspection area and can be used to examine sections of large objects without requiring objects to be moved or placed in darkroom. Bellows-type flexible shield has foam ends that seal surface to be inspected. Ultraviolet lamp and magnifier mounted in bellows permit localization of light. Rigid eyeshield hood allows in situ inspection.

Sugg, F. E.↗
NASA NTRS1977

Preliminary design analysis for the solar optical telescope main mirror actuator

The resolution of the SOT Gregorian telescope was maintained if the conic foci of the elliptical secondary and parabolic primary were made to coincide within plus or minus 38 microns across the prime focus plane and to within 5 microns in focus. An error in coincidence across the focal plane caused all point images to show additional coma with all the comatic tails pointing in the same direction. An error in focus became magnified by the square of the magnification of the secondary and simply increased the diameter of the point source. Offsetting or rastering the sun may be accomplished by swinging the primary in an arc about the point of coincidence of the conic foci so long as the coincidence is kept to within the tolerance stated.

Dunn, R. B.↗
NASA NTRS1978

Tidal effects in the O-type eclipsing system LY Aurigae

Existing photometry of the O9.5 III eclipsing binary LY Aur is discussed and combined into a visual mean light curve. It is found that the observed light curve is incompatible with previous solutions based on the Russell model, but a respectable fit to the observed light curve can be achieved by assuming von Zeipel gravity darkening provided the system is allowed to be in marginal contact, which involves an unrealistically large change in the mass ratio to obtain the appropriate eclipse depths and light ratio. The alternative possibilities are considered that the primary is tidally distorted more than expected for its relative radius and the observed mass ratio or that von Zeipel gravity darkening is not appropriate for O-type stars and photometric effects exist which magnify the effects of the primary's physical distortions in the light curve. A solution is favored in which the ratio of radii is near 0.75 and the primary is very highly gravity darkened relative to von Zeipel's law.

Eaton, J. A.↗
NASA NTRS1979

Late diagenetic indicators of buried oil and gas. 2: Direct detection experiment at Cement and Garza fields, Oklahoma and Texas, using enhanced LANDSAT 1 and 2 images

The author has identified the following significant results. The Cement oil field, Oklahoma, was a test site for an experiment designed to evaluate LANDSAT's capability to detect an alteration zone in surface rocks caused by hydrocarbon microseepage. Loss of iron and impregnation of sandstone by carbonate cements and replacement of gypsum by calcite were the major alteration phenomena at Cement. The bedrock alterations were partially masked by unaltered overlying beds, thick soils, and dense natural and cultivated vegetation. Interpreters, biased by detailed ground truth, were able to map the alteration zone subjectively using a magnified, filtered, and sinusoidally stretched LANDSAT composite image; other interpreters, unbiased by ground truth data, could not duplicate that interpretation.

Donovan, T. J.↗
NASA NTRS1979

Techniques for interpretation of geoid anomalies

For purposes of geological interpretation, techniques are developed to compute directly the geoid anomaly over models of density within the earth. Ideal bodies such as line segments, vertical sheets, and rectangles are first used to calculate the geoid anomaly. Realistic bodies are modeled with formulas for two-dimensional polygons and three-dimensional polyhedra. By using Fourier transform methods the two-dimensional geoid is seen to be a filtered version of the gravity field, in which the long-wavelength components are magnified and the short-wavelength components diminished.

Chapman, M. E.↗
NASA NTRS1979

Gravitational lens of the sun - Its potential for observations and communications over interstellar distances

The gravitational field of the sun acts as a spherical lens to magnify the intensity of radiation from a distant source along a semi-infinite focal line. A spacecraft anywhere on that line in principle could observe, eavesdrop, and communicate over interstellar distances, using equipment comparable in size and power with what is now used for interplanetary distances. If one neglects coronal effects, the maximum magnification factor for coherent radiation is inversely proportional to the wavelength, being 100 million at 1 millimeter. The principal difficulties are that the nearest point on the focal half-line is about 550 times the sun-earth distance, separate spacecraft would be needed to work with each stellar system of interest, and the solar corona would severely limit the intensity of coherent radiation while also restricting operations to relatively short wavelengths.

Eshleman, V. R.↗
NASA NTRS1981

Field limiter for solar radiometers

Lenses project solar image onto aperature to exclude circumsolar radiation, more precisely measuring energy captured by receiver aperatures of highly-concentrating solar thermal-energy converters. First version uses achromatic objective lens to form image of Sun at aperature ahead of radiometer cavity. Smaller second version with shorter focal length forms image magnified by another lens and thrown onto aperature. Both Versions require calibration against standard radiometer.

Berdahl, C. M.↗
NASA NTRS1980

Chromatically corrected virtual image visual display

An in-line, three element, large diameter, optical display lens is disclosed which has a front convex-convex element, a central convex-concave element, and a rear convex-convex element. The lens, used in flight simulators, magnifies an image presented on a television monitor and, by causing light rays leaving the lens to be in essentially parallel paths, reduces eye strain of the simulator operator.

Kahlbaum, W. M., Jr.↗