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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 271 records · Page 15
All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

Consolidation of Si3N4 by hot isostatic pressing

Silicon nitride (Si3N4) is being considered for gas turbine engine applications because present-day metallic alloys are rapidly approaching the limits of their temperature capabilities. The present investigation was undertaken to determine the feasibility of producing a sound, dense Si3N4 body without additives, using conventional gas hot-isostatic-pressing techniques and an uncommon hydraulic hot-isostatic-pressing technique. These two hot-isostatic-pressing (HIP) techniques produce much higher pressure (275-413 MN/sq m) than conventional hot-pressing techniques and have the potential of producing large bodies of desirable shapes. Evaluation was based on density measurement, microscopic examination, both optical and electron, and X-ray diffraction analysis.

Yeh, H. C.↗
NASA NTRS1991

Compact X-Ray And Extreme-Ultraviolet Monochromator

Monochromator for x-ray and extreme-ultraviolet radiation provides higher spectral resolution than achieved with thin-metal-foil broad-band-pass filters. Uses Bragg reflection to band-pass-filter radiation from high-intensity, broad-spectrum source. Operates over much broader x-ray and extreme-ultraviolet spectrum than devices based upon natural crystals. Intended to filter continuum radiation from sources like synchrotrons, laser plasma sources, free-electron lasers, and wigglers to produce monochromatic beams for testing and analysis of x-ray and extreme-ultraviolet telescopes and microscopes, for calibration of photographic films and detectors, for biological and biomedical research, for x-ray lithography, for processing of materials, and for research in properties of materials.

Hoover, Richard B.↗
NASA NTRS1990

Spatial Resolution and Detectability Limits in Thin-Film X-Ray Microanalysis

The major advantages of performing x-ray microanalysis in the analytical electron microscope (AEM) are the high compositional spatial resolution and the elemental analysis sensitivity. Unfortunately, there is usually a trade-off between these two advantages. This paper discusses the factors involved in the optimization of both spatial resolution and sensitivity during x-ray microanalysis and shows the results of such optimization experiments for several AEM instruments.

Goldstein, J. I.↗
NASA NTRS2004

Lunar and Planetary Science XXXV: Missions and Instruments: Hopes and Hope Fulfilled

The titles in this section include: 1) Mars Global Surveyor Mars Orbiter Camera in the Extended Mission: The MOC Toolkit; 2) Mars Odyssey THEMIS-VIS Calibration; 3) Early Science Operations and Results from the ESA Mars Express Mission: Focus on Imaging and Spectral Mapping; 4) The Mars Express/NASA Project at JPL; 5) Beagle 2: Mission to Mars - Current Status; 6) The Beagle 2 Microscope; 7) Mars Environmental Chamber for Dynamic Dust Deposition and Statics Analysis; 8) Locating Targets for CRISM Based on Surface Morphology and Interpretation of THEMIS Data; 9) The Phoenix Mission to Mars; 10) First Studies of Possible Landing Sites for the Phoenix Mars Scout Mission Using the BMST; 11) The 2009 Mars Telecommunications Orbiter; 12) The Aurora Exploration Program - The ExoMars Mission; 13) Electron-induced Luminescence and X-Ray Spectrometer (ELXS) System Development; 14) Remote-Raman and Micro-Raman Studies of Solid CO2, CH4, Gas Hydrates and Ice; 15) The Compact Microimaging Spectrometer (CMIS): A New Tool for In-Situ Planetary Science; 16) Preliminary Results of a New Type of Surface Property Measurement Ideal for a Future Mars Rover Mission; 17) Electrodynamic Dust Shield for Solar Panels on Mars; 18) Sensor Web for Spatio-Temporal Monitoring of a Hydrological Environment; 19) Field Testing of an In-Situ Neutron Spectrometer for Planetary Exploration: First Results; 20) A Miniature Solid-State Spectrometer for Space Applications - Field Tests; 21) Application of Laser Induced Breakdown Spectroscopy (LIBS) to Mars Polar Exploration: LIBS Analysis of Water Ice and Water Ice/Soil Mixtures; 22) LIBS Analysis of Geological Samples at Low Pressures: Application to Mars, the Moon, and Asteroids; 23) In-Situ 1-D and 2-D Mapping of Soil Core and Rock Samples Using the LIBS Long Spark; 24) Rocks Analysis at Stand Off Distance by LIBS in Martian Conditions; 25) Evaluation of a Compact Spectrograph/Detection System for a LIBS Instrument for In-Situ and Stand-Off Detection; 26) Analysis of Organic Compounds in Mars Analog Samples; 27) Report of the Organic Contamination Science Steering Group; 28) The Water-Wheel IR (WIR) - A Contact Survey Experiment for Water and Carbonates on Mars; 29) Mid-IR Fiber Optic Probe for In Situ Water Detection and Characterization; 30) Effects of Subsurface Sampling & Processing on Martian Simulant Containing Varying Quantities of Water; 31) The Subsurface Ice Probe (SIPR): A Low-Power Thermal Probe for the Martian Polar Layered Deposits; 32) Deploying Ground Penetrating Radar in Planetary Analog Sites to Evaluate Potential Instrument Capabilities on Future Mars Missions; 33) Evaluation of Rock Powdering Methods to Obtain Fine-grained Samples for CHEMIN, a Combined XRD/XRF Instrument; 34) Novel Sample-handling Approach for XRD Analysis with Minimal Sample Preparation; 35) A New Celestial Navigation Method for Mars Landers; 36) Mars Mineral Spectroscopy Web Site: A Resource for Remote Planetary Spectroscopy.

Source record↗
NASA NTRS2004

Robotic Subsurface Analyzer and Sample Handler for Resource Reconnaissance and Preliminary Site Assessment for ISRU Activities at the Lunar Cold Traps

Since the 1960s, claims have been made that water ice deposits should exist in permanently shadowed craters near both lunar poles. Recent interpretations of data from the Lunar Prospector-Neutron Spectrometer (LP- NS) confirm that significant concentrations of hydrogen exist, probably in the form of water ice, in the permanently shadowed polar cold traps. Yet, due to the large spatial resolution (45-60 Ian) of the LP-NS measurements relative to these shadowed craters (approx.5-25 km), these data offer little certainty regarding the precise location, form or distribution of these deposits. Even less is known about how such deposits of water ice might effect lunar regolith physical properties relevant to mining, excavation, water extraction and construction. These uncertainties will need to be addressed in order to validate fundamental lunar In Situ Resource Utilization (ISRU) precepts by 2011. Given the importance of the in situ utilization of water and other resources to the future of space exploration a need arises for the advanced deployment of a robotic and reconfigurable system for physical properties and resource reconnaissance. Based on a collection of high-TRL. designs, the Subsurface Analyzer and Sample Handler (SASH) addresses these needs, particularly determining the location and form of water ice and the physical properties of regolith. SASH would be capable of: (1) subsurface access via drilling, on the order of 3-10 meters into both competent targets (ice, rock) and regolith, (2) down-hole analysis through drill string embedded instrumentation and sensors (Neutron Spectrometer and Microscopic Imager), enabling water ice identification and physical properties measurements; (3) core and unconsolidated sample acquisition from rock and regolith; (4) sample handling and processing, with minimized contamination, sample containerization and delivery to a modular instrument payload. This system would be designed with three mission enabling goals, including: (1) a self-contained, low power, low mass, "black box'' configuration for operations from a lander, various classes of rovers or a surface-based platform with human assistance or robotic anchoring mechanisms; (2) reconfigurable and scalable sample handling for delivery to various types of instrumentation, depending on mission requirements; and (3) the use of advanced automation control and diagnostic techniques that will afford local human deployed, remote teleoperation and fully autonomous intelligent operations. Though a great deal of technology has been advanced toward these objectives, the SASH system faces significant design challenges, including the low gravity environment, various levels of autonomy in operations, radiation exposure, dust contamination, and temperature extremes and deltas. Significant input from the scientific and engineering communities, as well as a significant environmental testing program, will be required to guide the design process.

Gorevan, S. P.↗
NASA NTRS2012

Vesta and the HED Meteorites: Comparison of Spectral Properties

We present the main results obtained comparing the visible-near infrared (VIS-NIR) spectra Vesta s surface with howardites, eucrites, diogenites (HEDs). HEDs are commonly associated with Vesta based on spectral similarities. Because of such association, much effort is being made to merge the information from HEDs as well as Vestoids with that from Vesta to characterize the lithologic diversity of the surface of this asteroid and to infer clues regarding its thermal history. The Dawn spacecraft, orbiting around Vesta since July 2011, is performing detailed observations of this body and thus improving our knowledge of its properties. Dawn s scientific payload includes an imaging spectrometer, VIR-MS, sensitive to the VIS-NIR spectral range. VIR-MS began acquiring spectra during the approach phase that started in May 2011 and will continue its observations through July 2012 when the spacecraft will depart Vesta to travel to Ceres. The observations are uniformly distributed in latitude and longitude, allowing a global view of Vesta s crustal spectral properties. Using the information provided by VIR spectra, we studied the distribution of the spectral heterogeneities on the surface and used our findings to perform a comparison with HED spectra in the VIS-NIR spectral range searching for analogies and/or incompatibilities. In our analysis, we utilized a method to compare the results obtained at microscopic scale on HED samples and the one obtained at macroscopic scale on the surface of Vesta. The intent of this study is to improve our understanding of the connection between Vesta and the HEDs, which is one of the primary Dawn scientific objectives. Dawn VIR spectra are characterized by pyroxene absorptions and most of the surface materials exhibit howardite-like spectra. However, some large areas can be interpreted to be material richer in diogenite (based on pyroxenes band depths and band centers) and some others like eucrite-rich howardite terrains. In particular, VIR data strongly indicate in the south polar region (Rheasilvia) the presence of Mg-pyroxene-rich terrains. The hypothesis that Vesta is the HED parent body is consistent with, and strengthened by, the geologic and spectral context for pyroxene distribution provided by VIR on Dawn.

Ammannito, E.↗
NASA NTRS2013

Wear and Reactivity Studies of Melt infiltrated Ceramic Matrix Composite

As interest grows in the use of ceramic matrix composites (CMCs) for critical gas turbine engine components, the effects of the CMCs interaction with the adjoining structure needs to be understood. A series of CMC/material couples were wear tested in a custom elevated temperature test rig and tested as diffusion couples, to identify interactions. Specifically, melt infiltrated silicon carbide/silicon carbide (MI SiC/SiC) CMC was tested in combination with a nickel-based super alloy, Waspaloy, a thermal barrier coating, Yttria Stabilized Zirconia (YSZ), and a monolithic ceramic, silicon nitride (Si3N4). To make the tests more representative of actual hardware, the surface of the CMC was kept in the as-received state (not machined) with the full surface features/roughness present. Test results include: scanning electron microscope characterization of the surfaces, micro-structural characterization, and microprobe analysis.

Jarmon, David C.↗
NASA NTRS2017

Unveiling the Mysteries of Mars with a Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM)

Development of a miniaturized scanning electron microscope that will utilize the martian atmosphere to dissipate charge during analysis continues. This instrument is expected to be used on a future rover or lander to answer fundamental Mars science questions. To identify the most important questions, a survey was taken at the 47th Lunar and Planetary Science Conference (LPSC). From the gathered information initial topics were identified for a SEM on the martian surface. These priorities are identified and discussed below. Additionally, a concept of operations is provided with the goal of maximizing the science obtained with the minimum amount of communication with the instrument.

Lunar & Planetary Science & Exploration↗
NASA NTRS2020

Microscopic, Multipoint Characterization of Foreshock Bubbles With Magnetosphere Multiscale (MMS)

This work presents the first detailed analysis of foreshock bubbles (FBs) using high‐resolution Magnetospheric Multiscale (MMS) data. Between October 2017 and January 2019, MMS captured 10 foreshock transient events with burst resolution data that we show are consistent with FBs. One “textbook” event is examined and described in detail. Employing the multipoint nature of MMS, we demonstrate how the size and orientation, expansion speed, and distance since formation can be estimated. From all 10 events, FB sizes ranged from 1.1 to 9.9 RE (average of 4.4 RE), and expansion speeds ranged from 139 to 377 km/s (average of 257 km/s). FBs formed under a usual range of solar wind conditions between 3 and 20 RE upstream of Earth's bow shock. We also report on new features of FBs: deep and localized magnetic “holes” within the cores of FBs, where the total field strength drops to <1 nT.

D. L. Turner↗
NASA NTRS2005

Space Shuttle Columbia Aging Wiring Failure Analysis

A Space Shuttle Columbia main engine controller 14 AWG wire short circuited during the launch of STS-93. Post-flight examination divulged that the wire had electrically arced against the head of a nearby bolt. More extensive inspection revealed additional damage to the subject wire, and to other wires as well from the mid-body of Columbia. The shorted wire was to have been constructed from nickel-plated copper conductors surrounded by the polyimide insulation Kapton, top-coated with an aromatic polyimide resin. The wires were analyzed via scanning electron microscope (SEM), energy dispersive X-Ray spectroscopy (EDX), and electron spectroscopy for chemical analysis (ESCA); differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) were performed on the polyimide. Exemplar testing under laboratory conditions was performed to replicate the mechanical damage characteristics evident on the failed wires. The exemplar testing included a step test, where, as the name implies, a person stepped on a simulated wire bundle that rested upon a bolt head. Likewise, a shear test that forced a bolt head and a torque tip against a wire was performed to attempt to damage the insulation and conductor. Additionally, a vibration test was performed to determine if a wire bundle would abrade when vibrated against the head of a bolt. Also, an abrasion test was undertaken to determine if the polyimide of the wire could be damaged by rubbing against convolex helical tubing. Finally, an impact test was performed to ascertain if the use of the tubing would protect the wire from the strike of a foreign object.

McDaniels, Steven J.↗
NASA NTRS1992

Long Duration Space Materials Exposure (LDSE)

The Center on Materials for Space Structures (CMSS) at Case Western Reserve University is one of seventeen Commercial Centers for the Development of Space. It was founded to: (1) produce and evaluate materials for space structures; (2) develop passive and active facilities for materials exposure and analysis in space; and (3) develop improved material systems for space structures. A major active facility for materials exposure is proposed to be mounted on the exterior truss of the Space Station Freedom (SSF). This Long Duration Space Materials Exposure (LDSE) experiment will be an approximately 6 1/2 ft. x 4 ft. panel facing into the velocity vector (RAM) to provide long term exposure (up to 30 years) to atomic oxygen, UV, micro meteorites, and other low earth orbit effects. It can expose large or small active (instrumented) or passive samples. These samples may be mounted in a removable Materials Flight Experiment (MFLEX) carrier which may be periodically brought into the SSF for examination by CMSS's other SSF facility, the Space Materials Evaluation Facility (SMEF), which will contain a Scanning Electron Microscope, a Variable Angle & Scanning Ellipsometer, a Fourier Transform Infrared Spectrometer, and other analysis equipment. These facilities will allow commercial firms to test their materials in space and promptly obtain information on their materials survivability in the LEO environment.

Allen, David↗
NASA NTRS1977

Microscopic Lagrangian description of warm plasmas. I - Linear wave propagation. II - Nonlinear wave interactions

It is pointed out that the conventional iterative analysis of nonlinear plasma wave phenomena, which involves a direct use of Maxwell's equations and the equations describing the particle dynamics, leads to formidable theoretical and algebraic complexities, especially for warm plasmas. As an effective alternative, the Lagrangian method may be applied. It is shown how this method may be used in the microscopic description of small-signal wave propagation and in the study of nonlinear wave interactions. The linear theory is developed for an infinite, homogeneous, collisionless, warm magnetoplasma. A summary is presented of a perturbation expansion scheme described by Galloway and Kim (1971), and Lagrangians to third order in perturbation are considered. Attention is given to the averaged-Lagrangian density, the action-transfer and coupled-mode equations, and the general solution of the coupled-mode equations.

Kim, H.↗
NASA NTRS1977

High-resolution electron microscope

Employing scanning transmission electron microscope as interferometer, relative phases of diffraction maximums can be determined by analysis of dark field images. Synthetic aperture technique and Fourier-transform computer processing of amplitude and phase information provide high resolution images at approximately one angstrom.

Nathan, R.↗
NASA NTRS1975

Some wear studies on aircraft brake systems

An initial investigation of worn surfaces in friction pads and steel rotors used in current aircraft brakes was carried out using electron microprobe and X-ray diffraction analysis. It consists of the topographical study and the analysis of chemical element distribution. Based upon this initial examination, two approaches, microscopic and macroscopic have been conducted to interpret and formulate the wear mechanism of the aircraft brake materials. Microscopically, the wear particles were examined. The initiation and growth of surface cracks and the oxidation were emphasized in this investigation. Macroscopically, it has been found that, for the current copper based brake material sliding against 17-22 AS steel in a caliper brake, the surface temperature raised due to frictional heat is nonlinearly proportional to the load applied and slide time with speed at 1750 rpm. The wear of brake materials is then proportional to this temperature and is also a function of the melting temperature for copper.

Ho, T. L.↗
NASA NTRS1983

An optical search for 'X-ray quiet' quasars

Recent progress is described in an ongoing program to develop criteria for selecting faint QSOs in several tens of square degrees of sky previously surveyed by the Einstein X-ray Observatory. The physical properties of the selected QSOs are discussed in terms of the difficulties they present for QSO X-ray detection techniques. A series of F-plates for about two dozen fields have been obtained, but only a few of the X-ray images have been analyzed. The analysis of the plates consists of scanning several times with a binocular microscope. The number of positively identified QSOs per plate is 3, with a limiting magnitude of about 21 B. For about one half of the candidates, more than one emission line is identified at a consistent redshift, confirming that the object is a QSO. A table is presented which lists some of the flux density and luminosity data for the QSO objects detected thus far.

Anderson, S. F.↗
NASA NTRS1992

Research Instruments

The GENETI-SCANNER, newest product of Perceptive Scientific Instruments, Inc. (PSI), rapidly scans slides, locates, digitizes, measures and classifies specific objects and events in research and diagnostic applications. Founded by former NASA employees, PSI's primary product line is based on NASA image processing technology. The instruments karyotype - a process employed in analysis and classification of chromosomes - using a video camera mounted on a microscope. Images are digitized, enabling chromosome image enhancement. The system enables karyotyping to be done significantly faster, increasing productivity and lowering costs. Product is no longer being manufactured.

Source record↗
NASA NTRS1997

Modulation of statolith mass and grouping in white clover (Trifolium repens) growth in 1-g, microgravity and on the clinostat

Current models of gravity perception in higher plants focus on the buoyant weight of starch-filled amyloplasts as the initial gravity signal susceptor (statolith). However, no tests have yet determined if statolith mass is regulated to increase or decrease gravity stimulus to the plant. To this end, the root caps of white clover (Trifolium repens) grown in three gravity environments with three different levels of gravity stimulation have been examined: (i) 1-g control with normal static gravistimulation, (ii) on a slow clinostat with constant gravistimulation, and (iii) in the stimulus-free microgravity aboard the Space Shuttle. Seedlings were germinated and grown in the BioServe Fluid Processing Apparatus and root cap structure was examined at both light and electron microscopic levels, including three-dimensional cell reconstruction from serial sections. Quantitative analysis of the electron micrographs demonstrated that the starch content of amyloplasts varied with seedling age but not gravity condition. It was also discovered that, unlike in starch storage amyloplasts, all of the starch granules of statolith amyloplasts were encompassed by a fine filamentous, ribosome-excluding matrix. From light micrographic 3-D cell reconstructions, the absolute volume, number, and positional relationships between amyloplasts showed (i) that individual amyloplast volume increased in microgravity but remained constant in seedlings grown for up to three days on the clinostat, (ii) the number of amyloplasts per cell remained unchanged in microgravity but decreased on the clinostat, and (iii) the three-dimensional positions of amyloplasts were not random. Instead amyloplasts in microgravity were grouped near the cell centers while those from the clinostat appeared more dispersed. Taken together, these observations suggest that changing gravity stimulation can elicit feedback control over statolith mass by changing the size, number, and grouping of amyloplasts. These results support the starch-statolith theory of graviperception in higher plants and add to current models with a new feedback control loop as a mechanism for modulation of statolith responsiveness to inertial acceleration.

Flight Experiment↗