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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 811 records · Page 45
All sourcesNASA NTRSDOE OSTI
NASA NTRS1988

Hematology and biochemical findings of Spacelab 1 flight

The changes in erythropoiesis in astronauts caused by weightlessness was experimentally studied during the Spacelab 1 flight. Immediately after landing showed a mean decrease of 9,3 percent in the four astronauts. Neither hyperoxia nor an increase in blood phosphate caused the decrease. Red cell survival time and iron incorporation postflight were not significantly different from their preflight levels. Serum haptoglobin did not decrease, indicating that intravascular hemolysis was not a major cause of red cell mass change. An increase in serum ferritin after the second day of flight may have been caused by red cell breakdown early in flight. The space flight-induced decrease in red cell mass may result from a failure of erythropoesis to replace cells destroyed by the spleen soon after weightlessness is attained.

Leach, Carolyn S.↗
NASA NTRS1993

Thermography And Ultrasonics Find Flaws In Composites

Flaws first located in infrared imagery, then probed ultrasonically to reveal details. Thermographic and ultrasonic techniques, applied sequentially, constitute basis of developmental method of nondestructive inspection of structures made of lightweight composite materials like carbon-fiber/epoxy-matrix laminates. Method enables rapid detection and evaluation of damage and other flaws in composite structures. Does not require access to both sides of structure to be inspected.

Farley, Gary L.↗
NASA NTRS1992

Suevite superposition on the Bunte breccia in Noerdlinger Ries, Germany: New findings on the transport mechanism of impactites

Research undertaken in the last decades in Noerdlinger Ries, Germany, has repeatedly emphasized the sharp contact between Bunte breccia and suevite. However, extensive investigations into this layer boundary have not yet been possible due to insufficient outcrop ratios. New outcrops enabled an in-depth investigation into the superposition of suevite on the Bunte breccia, which is assigned a key role in interpreting the transport mechanisms of ejecta of large impact. In two quarries lying several kilometers east and south-southwest of the crater, the contact between the suevite and Bunte breccia was recorded in detailed sections on outcrops of over 50 m in length.

Bringemeier, D.↗
NASA NTRS1992

Findings of a review of spacecraft fire safety needs

Discussions from a workshop to guide UCLA and NASA investigators on the state of knowledge and perceived needs in spacecraft fire safety and its risk management are reviewed, for an introduction to an analytical and experimental project in this field. The report summarizes the workshop discussions and includes the visual aids used in the presentations. Probabilistic Safety Assessment (PSA) methods, which are currently not used, would be of great value to the designs and operation of future human-crew spacecraft. Key points in the discussions were the importance of understanding and testing smoldering as a likely fire scenario in space and the need for smoke damage modeling, since many fire-risk models ignore this mechanism and consider only heat damage.

Apostolakis, G. E.↗
NASA NTRS1993

Is a local bar a good place to find a companion? The near infrared morphology of Maffei 2

Maffei 2 is one of the closest large spiral galaxies lying just beyond the Local Group. It would probably be one of the most heavily studied galaxies in the sky were it not for the approximately 5 magnitudes of visual extinction resulting from its position behind the Galactic plane. It is the site of a burst of nuclear star formation indicated by strong infrared and radii continuum emission. Interferometric maps of CO-12 and CO-13 emission indicate that star formation is associated with a barlike structure consisting of arms of molecular gas that extend from within approximately 50 pc of the dynamical center out to a radius of at least 500 pc. HI maps have shown the galaxy to have an angular extent of approximately 15 feet and a neutral gas mass typical of a large spiral galaxy.

Hurt, Robert L.↗
NASA NTRS1993

Finding the rarest objects in the universe: A new, efficient method for discovering BL Lacertae objects

We present a new, efficient method for discovering new BL Lac Objects based upon the results of the Einstein Extended Medium Sensitivity Survey (EMSS). We have found that all x-ray selected BL Lacs are radio emitters, and further, that in a 'color-color' diagram (radio/optical and optical/x-ray) the BL Lac Objects occupy an area distinct from both radio loud quasars and the radio quiet QSOs and Seyferts which dominate x-ray selected samples. After obtaining radio counterparts via VLA 'snapshot' observations of a large sample of unidentified x-ray sources, the list of candidates is reduced. These candidates then can be confirmed with optical spectroscopy and/or polarimetry. Since greater than 70 percent of these sources are expected to be BL Lacs, the optical observations are very efficient. We have tested this method using unidentified sources found in the Einstein Slew Survey. The 162 Slew Survey x-ray source positions were observed with the VLA in a mixed B/C configuration at 6 cm resulting in 60 detections within 1.5 position error circle radii. These x-ray/optical/radio sources were then plotted, and 40 BL Lac candidates were identified. To date, 10 candidates have been spectroscopically observed resulting in 10 new BL Lac objects! Radio flux, optical magnitude, and polarization statistics (obtained in white light with the Steward Observatory 2.3 m CCD polarimeter) for each are given.

Stocke, John↗
NASA NTRS1992

A research experiment on facilitation and formation of joint research and development programs between government, industry, and universities: Overview, preliminary findings, and observations

Presented is an overview of an experiment to explore the free-market approach to public-private collaboration through the development and implementation of a joint venture mechanism to enable formation of R&D projects between government, industry and academia. Some preliminary results related to time-to-commercialization and economic competitiveness are discussed.

Shariq, Syed Z.↗
NASA NTRS1993

The tropical experiment of the Stratosphere-Troposphere Exchange Project (STEP) - Science objectives, operations, and summary findings

An overview is presented of the tropical component of STEP. The STEP cooperative experiments are described and summaries are presented of the STEP tropical ER-2 aircraft flights. STEP tropical results on dehydration and transfer and the mechanisms of upward transfer are summarized. Illustrations show flight paths for each sortie on satellite images and on 100 hPa synoptic flow charts, as well as the timing of flights with respect to overall cloudiness in the Australian region.

Russell, P. B.↗
NASA NTRS1956

A special method for finding body distortions that reduce the wave drag of wing and body combinations at supersonic speeds

For a given wing and supersonic Mach number, the problem of shaping an adjoining fuselage so that the combination will have a low wave drag is considered. Only fuselages that can be simulated by singularities (multipoles) distributed along the body axis are studied. However, the optimum variations of such singularities are completely specified in terms of the given wing geometry. An application is made to an elliptic wing having a biconvex section, a thickness-chord ratio equal to 0.05 at the root, and an aspect ratio equal to 3. A comparison of the theoretical results with a wind-tunnel experiment is also presented.

Lomax, Harvard↗
NASA NTRS1994

Program Finds Minimal Cut Sets

CUTSETS computer program identifies all minimal cut sets for given node. Software package contains subprograms that solve for minimal cut sets of fault trees and digraphs by use of object-oriented programming techniques. Cut-set codes used to solve graph models for reliability analysis and identify potential single-point failures in modeled system. Includes utility subprogram that converts popular COD-format diagraph-model-description files into text input files suitable for use with other CUT-SETS subprograms. FEAT (MSC-21873) and FIRM (MSC-21860). Written in C language.

Iverson, D. L.↗
NASA NTRS1991

Enhanced Damage-Resistant Optics for Spaceflight Laser Systems: Workshop findings and recommendations

NASA has defined a program to address critical laser-induced damage issues peculiar to its remote sensing systems. The Langley Research Center (LaRC), with input from the Goddard Space Flight Center (GSFC), has developed a program plan focusing on the certification of optical materials for spaceflight applications and the development of techniques to determine the reliability of such materials under extended laser exposures. This plan involves cooperative efforts between NASA and optics manufacturers to quantify the performance of optical materials for NASA systems and to ensure NASA's continued application of the highest quality optics possible for enhanced system reliability. A review panel was organized to assess NASA's optical damage concerns and to evaluate the effectiveness of the LaRC proposed program plan. This panel consisted of experts in the areas of laser-induced damage, optical coating manufacture, and the design and development of laser systems for space. The panel was presented information on NASA's current and planned laser remote sensing programs, laser-induced damage problems already encountered in NASA systems, and the proposed program plan to address these issues. Additionally, technical presentations were made on the state of the art in damage mechanisms, optical materials testing, and issues of coating manufacture germane to laser damage.

Schulze, Norman↗
NASA NTRS1991

Finding Fish from Above

This videotape shows how the use of satellites can help locate fish. The demonstration is intended for the fishing industry.

Source record↗
NASA NTRS1990

New findings and instrumentation from the NASA Lewis Microgravity Facility

The study of fundamental combustion and fluid physics phenomena in microgravity enables a new range of experiments to be performed since buoyancy-type flows are nearly eliminated, normally obscured forces and flows may be isolated, gravitational settling or sedimentation is nearly eliminated, and larger time or length scales in experiments become permissible. Some new phenomena found through ground-based microgravity research at NASA facilities is reviewed along with the instrumentation and drop tower facilities used in the research. Experiments are described in the areas of premixed gas combustion, droplet combustion, particle cloud combustion, liquid reorientation, and two-phase flow patterns. Future plans for instrumentation development are also outlined.

Ross, Howard D.↗
NASA NTRS1993

A direct approach to finding unknown boundary conditions in steady heat conduction

The capability of the boundary element method (BEM) in determining thermal boundary conditions on surfaces of a conducting solid where such quantities are unknown was demonstrated. The method uses a non-iterative direct approach in solving what is usually called the inverse heat conduction problem (IHCP). Given any over-specified thermal boundary conditions such as a combination of temperature and heat flux on a surface where such data is readily available, the algorithm computes the temperature field within the object and any unknown thermal boundary conditions on surfaces where thermal boundary values are unavailable. A two-dimensional, steady-state BEM program was developed and was tested on several simple geometries where the analytic solution was known. Results obtained with the BEM were in excellent agreement with the analytic values. The algorithm is highly flexible in treating complex geometries, mixed thermal boundary conditions, and temperature-dependent material properties and is presently being extended to three-dimensional and unsteady heat conduction problems. The accuracy and reliability of this technique was very good but tended to deteriorate when the known surface conditions were only slightly over-specified and far from the inaccessible surface.

Martin, Thomas J.↗