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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 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

The solid state detector technology for picosecond laser ranging

We developed an all solid state laser ranging detector technology, which makes the goal of millimeter accuracy achievable. Our design and construction philosophy is to combine the techniques of single photon ranging, ultrashort laser pulses, and fast fixed threshold discrimination while avoiding any analog signal processing within the laser ranging chain. The all solid state laser ranging detector package consists of the START detector and the STOP solid state photon counting module. Both the detectors are working in an optically triggered avalanche switching regime. The optical signal is triggering an avalanche current buildup which results in the generation of a uniform, fast risetime output pulse.

Prochazka, Ivan↗
NASA NTRS1992

Investigation of advanced propulsion technologies: The RAM accelerator and the flowing gas radiation heater

The two principal areas of advanced propulsion investigated are the ram accelerator and the flowing gas radiation heater. The concept of the ram accelerator is presented as a hypervelocity launcher for large-scale aeroballistic range applications in hypersonics and aerothermodynamics research. The ram accelerator is an in-bore ramjet device in which a projectile shaped like the centerbody of a supersonic ramjet is propelled in a stationary tube filled with a tailored combustible gas mixture. Combustion on and behind the projectile generates thrust which accelerates it to very high velocities. The acceleration can be tailored for the 'soft launch' of instrumented models. The distinctive reacting flow phenomena that have been observed in the ram accelerator are relevant to the aerothermodynamic processes in airbreathing hypersonic propulsion systems and are useful for validating sophisticated CFD codes. The recently demonstrated scalability of the device and the ability to control the rate of acceleration offer unique opportunities for the use of the ram accelerator as a large-scale hypersonic ground test facility. The flowing gas radiation receiver is a novel concept for using solar energy to heat a working fluid for space power or propulsion. Focused solar radiation is absorbed directly in a working gas, rather than by heat transfer through a solid surface. Previous theoretical analysis had demonstrated that radiation trapping reduces energy loss compared to that of blackbody receivers, and enables higher efficiencies and higher peak temperatures. An experiment was carried out to measure the temperature profile of an infrared-active gas and demonstrate the effect of radiation trapping. The success of this effort validates analytical models of heat transfer in this receiver, and confirms the potential of this approach for achieving high efficiency space power and propulsion.

Bruckner, A. P.↗
NASA NTRS1995

STS-94 Day 14 Highlights

On this fourteenth day of the STS-94 mission, the flight crew, Cmdr. James D. Halsell, Jr., Pilot Susan L. Still, Payload Cmdr, Janice E. Voss, Mission Specialists Michael L. Gernhardt and Donald A. Thomas, and Payload Specialists Gregory T. Linteris and Roger K. Crouch continue to focus on Columbia's Microgravity Science Laboratory mission. The seven astronauts work around the clock on two shifts supporting the more than 30 experiments in the Spacelab module. Work in the laboratory includes plant experiment and protein crystal growth status checks as well as work in the glovebox on the Coarsening in Solid-Liquid Mixtures experiment.

Source record↗
NASA NTRS2011

Experimental Testing and Modeling of a Pneumatic Regolith Delivery System for ISRU

Excavating and transporting planetary regolith are examples of surface activities that may occur during a future space exploration mission to a planetary body. Regolith, whether it is collected on the Moon, Mars or even an asteroid, consists of granular minerals, some of which have been identified to be viable resources that can be mined and processed chemically to extract useful by-products, such as oxygen, water, and various metals and metal alloys. Even the depleted "waste" material from such chemical processes may be utilized later in the construction of landing pads and protective structures at the site of a planetary base. One reason for excavating and conveying planetary regolith is to deliver raw regolith material to in-situ resource utilization (ISRU) systems. The goal of ISRU is to provide expendable supplies and materials at the planetary destination, if possible. An in-situ capability of producing mission-critical substances such as oxygen will help to extend the mission and its success, and will greatly lower the overall cost of a mission by either eliminating, or significantly reducing, the need to transport the same expendable materials from the Earth. In order to support the goals and objectives of present and future ISRU projects, NASA seeks technology advancements in the areas of regolith conveying. Such systems must be effective, efficient and provide reliable performance over long durations while being exposed to the harsh environments found on planetary surfaces. These conditions include contact with very abrasive regolith particulates, exposure to high vacuum or dry (partial) atmospheres, wide variations in temperature, reduced gravity, and exposure to space radiation. Regolith conveying techniques that combine reduced failure modes and low energy consumption with high material transfer rates will provide significant value for future space exploration missions to the surfaces of the moon, Mars and asteroids. Pneumatic regolith conveying has demonstrated itself to be a viable delivery system through testing under terrestrial and reduced gravity conditions in recent years. Modeling and experimental testing have been conducted at NASA Kennedy Space Center to study and advance pneumatic planetary regolith delivery systems in support of NASA's ISRU project. The goal of this work is to use the model to predict solid-gas flow patterns in reduced gravity environments for ISRU inlet gas line allowing the eductor inlet gas flow to vary and depend on the flow pattern developed at the eductor as inferred by the experimental observations.

Santiago-Maldonado, Edgardo↗
NASA NTRS2014

Development of Naphthalene PLIF for Visualizing Ablation Products From a Space Capsule Heat Shield

The Orion Multi-Purpose Crew Vehicle (MPCV) will use an ablative heat shield. To better design this heat shield and others that will undergo planetary entry, an improved understanding of the ablation process would be beneficial. Here, a technique developed at The University of Texas at Austin that uses planar laser-induced fluorescence (PLIF) of a low-temperature sublimating ablator (naphthalene) to enable visualization of the ablation products in a hypersonic flow is applied. Although high-temperature ablation is difficult and expensive to recreate in a laboratory environment, low-temperature sublimation creates a limited physics problem that can be used to explore ablation-product transport in a hypersonic flow-field. In the current work, a subscale capsule reentry vehicle model with a solid naphthalene heat shield has been tested in a Mach 5 wind tunnel. The PLIF technique provides images of the spatial distribution of sublimated naphthalene in the heat-shield boundary layer, separated shear layer, and backshell recirculation region. Visualizations of the capsule shear layer using both naphthalene PLIF and Schlieren imaging compared favorably. PLIF images have shown high concentrations of naphthalene in the capsule separated flow region, intermittent turbulent structures on the heat shield surface, and interesting details of the capsule shear layer structure. It was shown that, in general, the capsule shear layer appears to be more unsteady at lower angels of attack. The PLIF images demonstrated that during a wind tunnel run, as the model heated up, the rate of naphthalene ablation increased, since the PLIF signal increased steadily over the course of a run. Additionally, the shear layer became increasingly unsteady over the course of a wind tunnel run, likely because of increased surface roughness but also possibly because of the increased blowing. Regions with a relatively low concentration of naphthalene were also identified in the capsule backshell recirculation region and are most likely the result of cross-flow-induced vortices on the capsule afterbody.

Combs, C. S.↗
NASA NTRS2023

3D Printed TiO 2 Negative Electrodes for Sodium-Ion and Lithium-ion Batteries using Vat Photopolymerization

Additive manufacturing, also called 3D printing, represents a unique approach to develop three dimensional shape-conformable batteries with enhanced electrodes, specific surface area, improved ion diffusion, and power. For the first time, the formulation of a composite photocurable resin loaded with battery electrochemically active components was designed to feed a vat photopolymerization (VPP) 3D printer. In direct alignment with NASA’s Artemis mission goals to develop sustainable lunar energy storage infrastructure necessary to support long-term human operations, TiO 2 was here selected as an active material for the negative electrode for sodium-ion and lithium-ion batteries due to its abundance on the lunar surface. The TiO 2 loading in the composite photocurable resin and in the resulting VPP-printed negative electrode was increased as high as possible to enhance the electrochemical performance, while simultaneously ensuring the printability and acceptable mechanical strength for sample handling. The effect of thermal post-processing on the electrical, electrochemical and mechanical performance is reported. Finally, a configurational study is implemented to identify the impact of two different electrode designs (cubic and gyroid lattice unit cells) on the electrochemical performance. This work addresses the difficulties related to the introduction of solid particles within a VPP photocurable resin and the need for a compromise between the electrochemical performances and printability to obtain fully functional VPP-printed electrodes.

sodium-ion battery↗
NASA NTRS1990

Probabilistic failure assessment with application to solid rocket motors

A quantitative methodology is being developed for assessment of risk of failure of solid rocket motors. This probabilistic methodology employs best available engineering models and available information in a stochastic framework. The framework accounts for incomplete knowledge of governing parameters, intrinsic variability, and failure model specification error. Earlier case studies have been conducted on several failure modes of the Space Shuttle Main Engine. Work in progress on application of this probabilistic approach to large solid rocket boosters such as the Advanced Solid Rocket Motor for the Space Shuttle is described. Failure due to debonding has been selected as the first case study for large solid rocket motors (SRMs) since it accounts for a significant number of historical SRM failures. Impact of incomplete knowledge of governing parameters and failure model specification errors is expected to be important.

Jan, Darrell L.↗
NASA NTRS2003

3-Dimensional Topographic Models for the Classroom

We have recently undertaken a program to develop educational tools using 3-dimensional solid models of digital elevation data acquired by the Mars Orbital Laser Altimeter (MOLA) for Mars as well as a variety of sources for elevation data of the Earth. This work is made possible by the use of rapid prototyping technology to construct solid 3-Dimensional models of science data. We recently acquired rapid prototyping machine that builds 3-dimensional models in extruded plastic. While the machine was acquired to assist in the design and development of scientific instruments and hardware, it is also fully capable of producing models of spacecraft remote sensing data. We have demonstrated this by using Mars Orbiter Laser Altimeter (MOLA) topographic data and Earth based topographic data to produce extruded plastic topographic models which are visually appealing and instantly engage those who handle them.

Keller, J. W.↗
NASA NTRS1987

Direct solar-pumped iodine laser amplifier

The improvement on the collection system of the Tarmarack Solar Simulator beam was attemped. The basic study of evaluating the solid state laser materials for the solar pumping and also the work to construct a kinetic model algorithm for the flashlamp pumped iodine lasers were carried out. It was observed that the collector cone worked better than the lens assembly in order to collect the solar simulator beam and to focus it down to a strong power density. The study on the various laser materials and their lasing characteristics shows that the neodymium and chromium co-doped gadolinium scandium gallium garnet (Nr:Cr:GSGG) may be a strong candidate for the high power solar pumped solid state laser crystal. On the other hand the improved kinetic modeling for the flashlamp pumped iodine laser provides a good agreement between the theoretical model and the experimental data on the laser power output, and predicts the output parameters of a solar pumped iodine laser.

Han, Kwang S.↗
NASA NTRS2017

Treatment of Solid Rocket Motors that Complies with Established Protocols to Ensure Planetary Protection

This presentation discusses recent work being conducted by the National Aeronautics and Space Administration (NASA) at Marshall Space Flight Center (MSFC) to evaluate various methods that could be employed to provide for planetary protection of those solar system bodies that are candidates for extraterrestrial life, thus preventing contamination of such bodies. MSFC is presently involved in the development phase of the Europa Lander De-Orbital Stage (DOS) braking motor. In order to prevent bio-contamination of this Jovian satellite, three paths are currently being considered. The first is (1) Bio-Reduction of those microscopic organisms in or on the vehicle (in this case a solid rocket motor (SRM)) that might otherwise be transported during the mission. Possible methods being investigated include heat sterilization, application or incorporation of biocide materials, and irradiation. While each method can be made to work, effects on the SRM's components (propellant, liner, insulation, etc.) could well prove deleterious. A second path would be use of (2) Bio-Barrier material(s). So long as such barrier(s) can maintain their integrity, planetary protection should be afforded. Under the harsh conditions encountered during extended spaceflight (vacuum, temperature extremes, radiation), however, such barrier(s) could well experience a breach. Finally, a third path would be to perform (3) Pyrotechnic Sterilization of the SRM during its end-of-mission phase. Multiple pyrotechnic units would be triggered to ensure activation of such an event and provide for a final sterilization before vehicle impact. In light of Europa's stringent bio-reduction targets, the final and best choice to minimize risk will probably be some combination of the above.

Stefanski, Philip L.↗
NASA NTRS1997

Analysis of Technology for Solid State Coherent Lidar

Over the past few years, considerable advances have been made in the areas of the diode-pumped, eye-safe, solid state lasers, wide bandwidth, semiconductor detectors operating in the near-infrared region. These advances have created new possibilities for the development of low-cost, reliable, and compact coherent lidar systems for measurements of atmospheric winds and aerosol backscattering from a space-based platform. The work performed by the UAH personnel concentrated on design and analyses of solid state pulsed coherent lidar systems capable of measuring atmospheric winds from space, and design and perform laboratory experiments and measurements in support of solid state laser radar remote sensing systems which are to be designed, deployed, and used by NASA to measure atmospheric processes and constituents. A lidar testbed system was designed and analyzed by considering the major space operational and environmental requirements, and its associated physical constraints. The lidar optical system includes a wedge scanner and the compact telescope designed by the UAH personnel. The other major optical components included in the design and analyses were: polarizing beam splitter, routing mirrors, wave plates, signal beam derotator, and lag angle compensator. The testbed lidar optical train was designed and analyzed, and different design options for mounting and packaging the lidar subsystems and components and support structure were investigated. All the optical components are to be mounted in a stress-free and stable manner to allow easy integration and alignment, and long term stability. This lidar system is also intended to be used for evaluating the performance of various lidar subsystems and components that are to be integrated into a flight unit and for demonstrating the integrity of the signal processing algorithms by performing actual atmospheric measurements from a ground station.

Amzajerdian, Farzin↗
NASA NTRS1989

Recent advances in solid polymer electrolyte fuel cell technology with low platinum loading electrodes

Of all the fuel cell systems only alkaline and solid polymer electrolyte fuel cells are capable of achieving high power densities (greater than 1 W/sq cm) required for terrestrial and extraterrestrial applications. Electrode kinetic criteria for attaining such high power densities are discussed. Attainment of high power densities in solid polymer electrolyte fuel cells has been demonstrated earlier by different groups using high platinum loading electrodes (4 mg/sq cm). Recent works at Los Alamos National Laboratory and at Texas A and M University (TAMU) demonstrated similar performance for solid polymer electrolyte fuel cells with ten times lower platinum loading (0.45 mg/sq cm) in the electrodes. Some of the results obtained are discussed in terms of the effects of type and thickness of membrane and of the methods platinum localization in the electrodes on the performance of a single cell.

Srinivasan, Supramaniam↗
NASA NTRS2017

Growth Angle - a Microscopic View

The growth angle that is formed between the side of the growing crystal and the melt meniscus is an important parameter in the detached Bridgman crystal growth method, where it determines the extent of the crystal-crucible wall gap, and in the Czochralski and float zone methods, where it influences the size and stability of the crystals. The growth angle is a non-equilibrium parameter, defined for the crystal growth process only. For a melt-crystal interface translating towards the crystal (melting), there is no specific angle defined between the melt and the sidewall of the solid. In this case, the corner at the triple line becomes rounded, and the angle between the sidewall and the incipience of meniscus can take a number of values, depending on the position of the triple line. In this work, a microscopic model is developed in which the fluid interacts with the solid surface through long range van der Waals or Casimir dispersive forces. This growth angle model is applied to Si and Ge and compared with the macroscopic approach of Herring. In the limit of a rounded corner with a large radius of curvature, the wetting of the melt on the crystal is defined by the contact angle. The proposed microscopic approach addresses the interesting issue of the transition from a contact angle to a growth angle as the radius of curvature decreases.

Mazurak, K.↗
NASA NTRS1974

Solid medium thermal engine

A device is described which uses a single phase metallic working substance to convert thermal energy directly into mechanical energy. The device consists of a cylindrical metal tube which is free to rotate about its axis while being subjected to continuous bending moment stresses along the longitudinal axis of rotation. The stressing causes portions of the tube to be under compression while other parts are under tension which in turn causes the tube to rotate and provide mechanical energy.

Jedlicka, J. R.↗
NASA NTRS1994

Reduced hazard chemicals for solid rocket motor production

During the last three years. the NASA/Thiokol/industry team has developed and started implementation of an environmentally sound manufacturing plan for the continued production of solid rocket motors. NASA Marshall Space Flight Center (MSFC) and Thiokol Corporation have worked with other industry representatives and the U.S. Environmental Protection Agency (EPA) to prepare a comprehensive plan to eliminate all ozone depleting chemicals from manufacturing processes and reduce the use of other hazardous materials used to produce the space shuttle reusable solid rocket motors. The team used a classical approach for problem-solving combined with a creative synthesis of new approaches to attack this challenge.

Larry A. Caddy↗
NASA NTRS2021

Plasma Assisted Trash Conversion with CO2 Carrier Gas

A sub-atmospheric plasma solid-to-gas conversion system operating under 500 W was tested to be viable for waste conversion to a gaseous state without the use of a feedstock gas as shown in previous plasma torch works. This manuscript lays the groundwork into the feasibility of low-pressure solid-to-gas conversion, reaction chemistry of the by-product gases, and power consumption. The results have shown the possibility of gasification at reduced pressures without the consumable use of a feedstock carrier gas in previous studies. Thus far, the percent gasification averaged around 36% in pre-pellet trials, with the system being far from optimized. The products include H2, CO2, CO, C2H4, and C2H6. Hydrogen production was higher as expected in a CO2-like environment once the gasification process begins. The energy required to generate the plasma was on the order of that previously reported at atmospheric pressures. The ability to eliminate the need for any consumables that were required in previous iterations greatly improves the cost and operational logistics of plasma gasification equipment. Although further development of the system is needed for increased gasification percentages, elimination of useable commodities greatly favors such a system for trash management beyond low Earth orbit.

Malay Shah↗
NASA NTRS1977

Variation in the thermionic work function of semiconductor powders exposed to electromagnetic radiation

The study of the variation of thermoelectronic work function potential of TiO2 in the presence of isobutane shows that this gas is not adsorbed on this solid, in either the presence or the absence of ultraviolet radiation. These results, as well as those obtained in a previous work, lead to the mechanism of the photo-oxidation of isobutane at room temperature, in which excited atomic oxygen is the active species.

Bourasseau, S.↗
NASA NTRS1973

Addition of three-dimensional isoparametric elements to NASA structural analysis program (NASTRAN)

Implementation is made of the three-dimensional family of linear, quadratic and cubic isoparametric solid elements into the NASA Structural Analysis program, NASTRAN. This work included program development, installation, testing, and documentation. The addition of these elements to NASTRAN provides a significant increase in modeling capability particularly for structures requiring specification of temperatures, material properties, displacements, and stresses which vary throughout each individual element. Complete program documentation is presented in the form of new sections and updates for direct insertion to the three NASTRAN manuals. The results of demonstration test problems are summarized. Excellent results are obtained with the isoparametric elements for static, normal mode, and buckling analyses.

Field, E. I.↗