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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 1,351 records · Page 75
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

Experimental instrumentation system for the Phased Array Mirror Extendible Large Aperture (PAMELA) test program

Adaptive optics are used in telescopes for both viewing objects with minimum distortion and for transmitting laser beams with minimum beam divergence and dance. In order to test concepts on a smaller scale, NASA MSFC is in the process of setting up an adaptive optics test facility with precision (fraction of wavelengths) measurement equipment. The initial system under test is the adaptive optical telescope called PAMELA (Phased Array Mirror Extendible Large Aperture). Goals of this test are: assessment of test hardware specifications for PAMELA application and the determination of the sensitivities of instruments for measuring PAMELA (and other adaptive optical telescopes) imperfections; evaluation of the PAMELA system integration effort and test progress and recommended actions to enhance these activities; and development of concepts and prototypes of experimental apparatuses for PAMELA.

Boykin, William H., Jr.↗
NASA NTRS1993

A new tape product for optical data storage

A new tape product has been developed for optical data storage. Laser data recording is based on hole or pit formation in a low melting metallic alloy system. The media structure, sputter deposition process, and media characteristics, including write sensitivity, error rates, wear resistance, and archival storage are discussed.

Larsen, T. L.↗
NASA NTRS1999

Illuminating Development

Through the support of the NASA SBIR program, Control Vision, Inc. developed novel video techniques for clear, high resolution, real-time imaging of high temperature, high-energy industrial processes, such as welding, plasma arc spraying (coating), arc furnaces, metal casting and refractories (ceramics) melting. The Control Vision systems use reflected laser or strobe illumination, combined with ultra-short exposure times to create video, including the allowance of particle imaging velocimetry (PIV) of fast moving powder particles buried within a plasma stream.

Source record↗
NASA NTRS2003

High Resolution Spectroscopy to Support Atmospheric Measurements

Spectroscopic parameters (such as line position, intensity, broadening and shifting coefficients and their temperature dependences, line mixing coefficients etc.) for various molecular species of atmospheric interest are determined. In order to achieve these results, infrared spectra of several molecular bands are obtained using high-resolution recording instruments such as tunable diode laser spectrometer and Fourier transform spectrometers. Using sophisticated analysis routines (Multispectrum nonlinear least squares technique) these high-resolution infrared spectra are processed to determine the various spectral line parameters that are cited above. Spectra were taken using the McMath-Pierce Fourier transform spectrometer (FTS) at the National Solar Observatory on Kitt Peak, Arizona as well as the Bruker FTS at the Pacific Northwest National Laboratory (PNNL) at Richland, Washington. Most of the spectra are acquired not only at room temperature, but also at several different cold temperatures. This procedure is necessary to study the variation of the spectral line parameters as a function of temperature in order to simulate the Earth's and other planetary atmospheric environments. Depending upon the strength or weakness of the various bands recorded and analyzed, the length(s) of the absorption cells in which the gas samples under study are kept varied from a few centimeters up to several meters and the sample temperatures varied from approximately +30 C to -63 C. Research on several infrared bands of various molecular species and their isotopomers are undertaken. Those studies are briefly described.

Venkataraman, Malathy Devi↗
NASA NTRS1995

In-Flight Thermal Performance of the Lidar In-Space Technology Experiment

The Lidar In-Space Technology Experiment (LITE) was developed at NASA s Langley Research Center to explore the applications of lidar operated from an orbital platform. As a technology demonstration experiment, LITE was developed to gain experience designing and building future operational orbiting lidar systems. Since LITE was the first lidar system to be flown in space, an important objective was to validate instrument design principles in such areas as thermal control, laser performance, instrument alignment and control, and autonomous operations. Thermal and structural analysis models of the instrument were developed during the design process to predict the behavior of the instrument during its mission. In order to validate those mathematical models, extensive engineering data was recorded during all phases of LITE's mission. This inflight engineering data was compared with preflight predictions and, when required, adjustments to the thermal and structural models were made to more accurately match the instrument s actual behavior. The results of this process for the thermal analysis and design of LITE are presented in this paper.

Roettker, William↗
NASA NTRS2004

Advanced Computational Modeling of Vapor Deposition in a High-pressure Reactor

In search of novel approaches to produce new materials for electro-optic technologies, advances have been achieved in the development of computer models for vapor deposition reactors in space. Numerical simulations are invaluable tools for costly and difficult processes, such as those experiments designed for high pressures and microgravity conditions. Indium nitride is a candidate compound for high-speed laser and photo diodes for optical communication system, as well as for semiconductor lasers operating into the blue and ultraviolet regions. But InN and other nitride compounds exhibit large thermal decomposition at its optimum growth temperature. In addition, epitaxy at lower temperatures and subatmospheric pressures incorporates indium droplets into the InN films. However, surface stabilization data indicate that InN could be grown at 900 K in high nitrogen pressures, and microgravity could provide laminar flow conditions. Numerical models for chemical vapor deposition have been developed, coupling complex chemical kinetics with fluid dynamic properties.

Cardelino, Beatriz H.↗
NASA NTRS2004

Advanced Computational Modeling of Vapor Deposition in a High-Pressure Reactor

In search of novel approaches to produce new materials for electro-optic technologies, advances have been achieved in the development of computer models for vapor deposition reactors in space. Numerical simulations are invaluable tools for costly and difficult processes, such as those experiments designed for high pressures and microgravity conditions. Indium nitride is a candidate compound for high-speed laser and photo diodes for optical communication system, as well as for semiconductor lasers operating into the blue and ultraviolet regions. But InN and other nitride compounds exhibit large thermal decomposition at its optimum growth temperature. In addition, epitaxy at lower temperatures and subatmospheric pressures incorporates indium droplets into the InN films. However, surface stabilization data indicate that InN could be grown at 900 K in high nitrogen pressures, and microgravity could provide laminar flow conditions. Numerical models for chemical vapor deposition have been developed, coupling complex chemical kinetics with fluid dynamic properties.

Cardelino, Beatriz H.↗
NASA NTRS2005

The Diversity of Martian Volcanic features as Seen in the MOC, THEMIS, and MOM Data Sets

This one-year project (which included one-year no-cost tension) focused on the evolution of the summit areas of Martian volcanoes. It extended the studies conducted under an earlier MDAP project (Grant NAG5-9576, Principal Investigator P. Mouginis- Mark). By using data collected from the Mars Orbiter Camera (MOC), Thermal Emission Imaging System (THEMIS), and the Mars Orbiter Laser Altimeter (MOLA) instruments, we tried to better understand the diversity of constructional volcanism on Mars, and hence further understand the eruption processes. By inspecting THEMIS and MOC data, we explored the following four questions: (1) Where might near-surface volatiles have been released at the summits of the Tharsis volcanoes? Is the trapping and subsequent remobilization of degassed volatiles [Scott and Wilson, 19991 adequate to produce eruptions responsible for extensive deposits such as the ones identified on Arsia Mons [Mouginis-Mark, 2002]? To answer this question, we investigated the diversity of eruption styles by studying the summit areas of Arsia, Pavonis and Ascraeus Montes. (2) What are the geomorphic characteristics of the valley system on Hecates Tholus, a volcano that we have previously proposed experienced explosive activity [Mouginis-Murk et al., 1982]? Our inspection of THEMIS data suggests that water release on the volcano took place over an extended period of time, suggesting that hydrothermal activity may have taken place here. (3) How similar are the collapse processes observed at Martian and terrestrial calderas? New THEMIS data provide a more complete view of the entire Olympus Mons caldera, thereby enabling the comparison with the collapse features at Masaya volcano, Nicaragua, to be investigated. (4) What can we learn about the emplacement of long lava flows in the lava plains of Eastern Tharsis? The result of this work provided a greater understanding of the temporal and spatial variations in the eruptive history of volcanoes on Mars, and the influence of the volatiles within the top few kilometers of the volcanic edifice. This relationship in turn pertains to the availability of volatiles (both juvenile magmatic volatiles and ground water contained within the near-surface rocks) and to magma supply rates at appreciable distances (tens to hundreds of kilometers) from the centers of volcanoes. Explosive volcanism on Mars, a major factor in the release of water at the surface, may have been driven not only by volatiles within the parental melt, but also by magma encountering water or ice at shallow depth within the volcano [Mouginis-Mark et al., 1982, 1988; Crown and Greeley, 1993; Robinson et al., 19931.

Mouginis-Mark, Peter J.↗
NASA NTRS2015

Summary of Liquid Oxygen/Hydrogen, Direct Metal Laser Sintering Injector Testing and Evaluation Effort at Marshall Space Flight Center

The last several years have witnessed a significant advancement in the area of additive manufacturing technology. One area that has seen substantial expansion in application has been laser sintering (or melting) in a powder bed. This technology is often termed 3D printing or various acronyms that may be industry, process, or company specific. Components manufactured via 3D printing have the potential to significantly reduce development and fabrication time and cost. The usefulness of 3D printed components is influenced by several factors such as material properties and surface roughness. This paper details three injectors that were designed, fabricated, and tested in order to evaluate the utility of 3D printed components for rocket engine applications. The three injectors were tested in a hot‐fire environment with chamber pressures of approximately 1400 psia. One injector was a 28 element design printed by Directed Manufacturing. The other two injectors were identical 40 element designs printed by Directed Manufacturing and Solid Concepts. All the injectors were swirl‐coaxial designs and were subscale versions of a full‐scale injector currently in fabrication. The test and evaluation programs for the 28 element and 40 element injectors provided a substantial amount of data that confirms the feasibility of 3D printed parts for future applications. The operating conditions of previously tested, conventionally manufactured injectors were reproduced in the 28 and 40 element programs in order to contrast the performance of each. Overall, the 3D printed injectors demonstrated comparable performance to the conventionally manufactured units. The design features of the aforementioned injectors can readily be implemented in future applications with a high degree of confidence.

Barnett, Gregory↗
NASA NTRS1973

Remote Measurement of Atmospheric Temperatures By Raman Lidar

The Raman shifted return of a lidar, or optical radar, system has been utilized to make atmospheric temperature measurements. These measurements were made along a horizontal path at temperatures between -20 C and +30 C and at ranges of about 100 meters. The temperature data were acquired by recording the intensity ratio of two portions of the Raman spectrum which were simultaneously sampled from a preset range. The lidar unit employed in this testing consisted of a 4 joule-10ppm laser operating at 694.3 nm, a 10-inch Schmidt-Cassegrain telescope, and a system of time-gated detection and signal processing electronics. The detection system processed three return signal wavelength intervals - two intervals along the rotational Raman scattered spectrum and one interval centered at the Rayleigh-Mie scattered wavelength. The wavelength intervals were resolved by using a pellicle beam splitter and three optical interference filters. Raman return samples were taken from one discrete range segment during each test shot and the signal intensities were displayed in digital format. The Rayleigh-Mie techniques. The test site utilized to evaluate this measurement technique encompassed a total path length of 200 meters. Major components of the test site included a trailer-van housing the lidar unit, a controlled environment test zone, and a beam terminator. The control zone which was located about 100 meters from the trailer was 12 meters in length, 2.4 meters in diameter, and was equipped with hinged doors at each end. The temperature of the air inside the zone could be either raised or lowered with respect to ambient air through the use of infrared heaters or a liquid-nitrogen cooling system. Conditions inside the zone were continuously monitored with a thermocouple rake assembly. The test path length was terminated by a 1.2 meter square array of energy absorbing cones and a flat black screen. Tests were initially conducted at strictly ambient conditions utilizing the normal outside air temperatures as a test parameter. These tests provided a calibration of the Raman intensity ratio as a function of' temperature for the particular optical-filter arrangement used in this system while also providing a test of' the theoretical prediction formulated in the design of the system. Later tests utilized zone temperatures above and below ambient to provide temperature gradient data. These tests indicate that ten shots, or one minute of' data acquisition, from a 100 meter range can provide absolute temperature measurements with an accuracy of + 30 C and a range resolution of about 5 meters. Because this measurement accuracy compares well with that predicted for this particular unit, it is suggested that a field-application system could be built with signif'icant improvements in both absolute accuracy and range.

Salzman, Jack A.↗
NASA NTRS2023

A 3D Printable Alloy Designed for Extreme Environments

Multiprincipal-element alloys are an enabling class of materials owing to their impressive mechanical and oxidation-resistant properties, especially in extreme environments. Here we develop a new oxide-dispersion-strengthened NiCoCr-based alloy using a model-driven alloy design approach and laser-based additive manufacturing. This oxide-dispersion-strengthened alloy, called GRX-810, uses laser powder bed fusion to disperse nanoscale Y 2 O 3 particles throughout the microstructure without the use of resource-intensive processing steps such as mechanical or in situ alloying. We show the successful incorporation and dispersion of nanoscale oxides throughout the GRX-810 build volume via high-resolution characterization of its microstructure. The mechanical results of GRX-810 show a twofold improvement in strength, over 1,000-fold better creep performance and twofold improvement in oxidation resistance compared with the traditional polycrystalline wrought Ni-based alloys used extensively in additive manufacturing at 1,093 °C. The success of this alloy highlights how model-driven alloy designs can provide superior compositions using far fewer resources compared with the ‘trial-and-error’ methods of the past. These results showcase how future alloy development that leverages dispersion strengthening combined with additive manufacturing processing can accelerate the discovery of revolutionary materials.

Timothy M. Smith↗
NASA NTRS1976

Lunar motion analysis and laser data management

Work completed in lunar motion analysis and laser data management during the period July 1, 1971 - September 30, 1975 was reported. In this context, analysis refers to theoretical or numerical studies involving real or potential applications of such observations to improvement of the physical model, and data management refers to the process by which observed photon events are turned into observations and are made available to potential users. The data analysis work included: (1) bringing to operational status of computer programs for the numerical integration of the lunar orbit motion and for the application of lunar laser time delays for the improvement of the parameters of the physical model, (2) program improvement and program integrity, (3) three-dimensional ephemeris, and (4) miscellaneous independent studies. The data management work included: (1) data identification, (2) observatory interfaces, and (3) data distribution.

Mulholland, J. D.↗
NASA NTRS2005

NASA Tech Briefs, January 2005

Topics covered include: Fiber-Optic Sensor Would Monitor Growth of Polymer Film; Sensors for Pointing Moving Instruments Toward Each Other; Pd/CeO2/SiC Chemical Sensors; Microparticle Flow Sensor; Scattering-Type Surface-Plasmon-Resonance Biosensors; Diode-Laser-Based Spectrometer for Sensing Gases; Improved Cathode Structure for a Direct Methanol Fuel Cell; X-Band, 17-Watt Solid-State Power Amplifier; Improved Anode for a Direct Methanol Fuel Cell; Tools for Designing and Analyzing Structures; Interactive Display of Scenes with Annotations; Solving Common Mathematical Problems; Tools for Basic Statistical Analysis; Program Calculates Forces in Bolted Structural Joints; Integrated Structural Analysis and Test Program; Molybdate Coatings for Protecting Aluminum Against Corrosion; Synthesizing Diamond from Liquid Feedstock; Modifying Silicates for Better Dispersion in Nanocomposites; Powder-Collection System for Ultrasonic/Sonic Drill/Corer; Semiautomated, Reproducible Batch Processing of Soy; Hydrogen Peroxide Enhances Removal of NOx from Flue Gases; Subsurface Ice Probe; Real-Time Simulation of Aeroheating of the Hyper-X Airplane; Using Laser-Induced Incandescence To Measure Soot in Exhaust; Method of Real-Time Principal-Component Analysis; Insect-Inspired Flight Control for Unmanned Aerial Vehicles; Domain Compilation for Embedded Real-Time Planning; Semantic Metrics for Analysis of Software; Simulation of Laser Cooling and Trapping in Engineering Applications; Large Fluvial Fans and Exploration for Hydrocarbons; Doping-Induced Interband Gain in InAs/AlSb Quantum Wells; Development of Software for a Lidar-Altimeter Processor; Upgrading the Space Shuttle Caution and Warning System; and Fractal Reference Signals in Pulse-Width Modulation.

Source record↗
NASA NTRS2010

Time-Gating Processes in Intra-Cavity Mode-Locking Devices Like Saturable Absorbers and Kerr Cells

Photons are non-interacting entities. Light beams do not interfere by themselves. Light beams constituting different laser modes (frequencies) are not capable of re-arranging their energies from extended time-domain to ultra-short time-domain by themselves without the aid of light-matter interactions with suitable intra-cavity devices. In this paper we will discuss the time-gating properties of intra-cavity "mode-locking" devices that actually help generate a regular train of high energy wave packets.

Prasad, Narasimha↗
NASA NTRSDate not supplied

Recent Advances in LIBS for Real-Time Detection of Silicone Contaminants on CFRP Surfaces

Laser induced breakdown spectroscopy (LIBS) is a materials characterization technique that has been advanced and refined to provide in situ, real-time quality control of carbon fiber reinforced polymer (CFRP) surfaces. As part of an effort to improve process control for adhesive bonding, a LIBS system was designed and assembled at NASA Langley Research Center (LaRC) to enable detection of ultralow concentrations of silicone contamination on CFRP adherends. The LIBS instrument provides high sensitivity detection and quasi-nondestructive surface characterization of CFRP adherends prior to adhesive bonding. This review focuses on the advancements at LaRC using LIBS as a quality control tool for the detection of silicone contaminants for improved adhesive bonding reliability of CFRP materials. This work describes how the LIBS technique was advanced by analyzing the laser parameters, studying the laser-matter interactions, and performing time-resolved measurements to determine the optimal plasma conditions for elemental detection. In addition, LIBS results were compared to X-ray photoelectron spectroscopy data to enable quantitative analysis from analytical calibration curves. Examples are shown of how to perform surface mapping of silicone contamination. Finally, a brief discussion is also presented on LIBS instrumentation, recommendations for laser parameters and instrumentation components, and LIBS technique maturity.

Surface characterization, Carbon fiber reinforced ↗
NASA NTRS1995

Comparison of Retracking Algorithms Using Airborne Radar and Laser Altimeter Measurements of the Greenland Ice Sheet

This paper compares four continental ice sheet radar altimeter retracking algorithms using airborne radar and laser altimeter data taken over the Greenland ice sheet in 1991. The refurbished Advanced Application Flight Experiment (AAFE) airborne radar altimeter has a large range window and stores the entire return waveform during flight. Once the return waveforms are retracked, or post-processed to obtain the most accurate altitude measurement possible, they are compared with the high-precision Airborne Oceanographic Lidar (AOL) altimeter measurements. The AAFE waveforms show evidence of varying degrees of both surface and volume scattering from different regions of the Greenland ice sheet. The AOL laser altimeter, however, obtains a return only from the surface of the ice sheet. Retracking altimeter waveforms with a surface scattering model results in a good correlation with the laser measurements in the wet and dry-snow zones, but in the percolation region of the ice sheet, the deviation between the two data sets is large due to the effects of subsurface and volume scattering. The Martin et al model results in a lower bias than the surface scattering model, but still shows an increase in the noise level in the percolation zone. Using an Offset Center of Gravity algorithm to retrack altimeter waveforms results in measurements that are only slightly affected by subsurface and volume scattering and, despite a higher bias, this algorithm works well in all regions of the ice sheet. A cubic spline provides retracked altitudes that agree with AOL measurements over all regions of Greenland. This method is not sensitive to changes in the scattering mechanisms of the ice sheet and it has the lowest noise level and bias of all the retracking methods presented.

Ferraro, Ellen J.↗
NASA NTRS2000

Laser Lightcraft Performance

The purpose of this study is to establish the technical ground for modeling the physics of laser powered pulse detonation phenomenon. The principle of the laser power propulsion is that when high-powered laser is focused at a small area near the surface of a thruster, the intense energy causes the electrical breakdown of the working fluid (e.g. air) and forming high speed plasma (known as the inverse Bremsstrahlung, IB, effect). The intense heat and high pressure created in the plasma consequently causes the surrounding to heat up and expand until the thrust producing shock waves are formed. This complex process of gas ionization, increase in radiation absorption and the forming of plasma and shock waves will be investigated in the development of the present numerical model. In the first phase of this study, laser light focusing, radiation absorption and shock wave propagation over the entire pulsed cycle are modeled. The model geometry and test conditions of known benchmark experiments such as those in Myrabo's experiment will be employed in the numerical model validation simulations. The calculated performance data will be compared to the test data.

Chen, Yen-Sen↗
NASA NTRS1993

Introduction of laser initiation for the 48-inch Advanced Solid Rocket Motor (ASRM) test motors at Marshall Space Flight Center (MSFC)

The Advanced Solid Rocket Motor is a new design for the Space Shuttle Solid Rocket Booster. The new design will provide more thrust and more payload capability, as well as incorporating many design improvements in all facets of the design and manufacturing process. A 48-inch (diameter) test motor program is part of the ASRM development program. This program has multiple purposes for testing of propellent, insulation, nozzle characteristics, etc. An overview of the evolution of the 48-inch ASRM test motor ignition system which culminated with the implementation of a laser ignition system is presented. The laser system requirements, development, and operation configuration are reviewed in detail.

Zimmerman, Chris J.↗