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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Transfer learning driven design optimization for inertial confinement fusion

Transfer learning is a promising approach to create predictive models that incorporate simulation and experimental data into a common framework. In this technique, a neural network is first trained on a large database of simulations and then partially retrained on sparse sets of experimental data to adjust predictions to be more consistent with reality. Previously, this technique has been used to create predictive models of Omega [Humbird et al., IEEE Trans. Plasma Sci. 48, 61–70 (2019)] and NIF [Humbird et al., Phys. Plasmas 28, 042709 (2021); Kustowski et al., Mach. Learn. 3, 015035 (2022)] inertial confinement fusion (ICF) experiments that are more accurate than simulations alone. Here, in this work, we conduct a transfer learning driven hypothetical ICF campaign in which the goal is to maximize experimental neutron yield via Bayesian optimization. The transfer learning model achieves yields within 5% of the maximum achievable yield in a modest-sized design space in fewer than 20 experiments. Furthermore, we demonstrate that this method is more efficient at optimizing designs than traditional model calibration techniques commonly employed in ICF design. Such an approach to ICF design could enable robust optimization of experimental performance under uncertainty.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2026

Multidisciplinary Design, Analysis, and Optimization (MDO) for Co-Designed Transmission & Distribution Electric Grid Planning

This paper describes early experiences and example use cases applying multi-disciplinary design analysis and optimization (MDO) to the integrated design of power grids. Adapted from aerospace, MDO enables combining multiple existing tools into a coordinated optimization. Here we use MDO to simultaneously capture integrated transmission-distribution and investment-engineering trade-offs in an automated framework. Example use cases showcase prototype interactions among existing grid models using MDO and hint at the types of integrated analyses enabled by this approach. In addition, we share experiences and thoughts on grid-specific challenges and opportunities to help advance further work in this area.

24 POWER TRANSMISSION AND DISTRIBUTION↗
NASA NTRS1975

Superconducting magnets for space flight

The operating principle and application of superconducting magnetic spectrometers for cosmic ray analysis are described. Magnetic spectrometer experiments are thought to be possible in the areas of charge composition and its possible energy dependence, isotopic separation up to several GeV/n, electrons and positrons energy spectra, galactic secondary antiprotons, searches for primordial antimatter, searches for substructure in energy spectra, and gamma ray astronomy. Operational problems associated with the magnets are discussed, and a possible shuttle payload is also described.

Golden, R. L.↗
NASA NTRS1973

Computer-Generated Movies for Mission Planning

Computer-generated movies help the viewer to understand mission dynamics and get quantitative details. Sample movie frames demonstrate the uses and effectiveness of movies in mission planning. Tools needed for movie-making include computer programs to generate images on film and film processing to give the desired result. Planning scenes to make an effective product requires some thought and experience. Viewpoints and timing are particularly important. Lessons learned so far and problems still encountered are discussed.

Roberts, P. H., Jr.↗
NASA NTRS1996

A Cross-Industry Analysis of LOFT Debriefings

Line Oriented Simulation (LOS) iss widely used to provide crews opportunities to practice Cockpit Resource Management (CRM) concepts in realistic, challenging simulated flight situations. LOS includes both Line Oriented Flight Training (LOFT), the original "non-jeopardy" form in which the crews are not graded on their performance, and Line Oriented Evaluation (LOE). In LOE, crews are graded, which is required in those airlines that participate in the FAA's Advanced Qualification Program (ALP). How much crews learn in LOS arid take back to the line hinges on the effectiveness of the debriefing that follows the LOS. The simulation itself is a busy, intense experience, and thoughtful discussion afterwards is necessary for the crew to sort out and interpret what happened and why. Instructors are expected to lead briefings in a way that encourages crew members to analyze for themselves their performance in the LOS. Rather than lecturing the crew in the traditional manner on what they did right and wrong, the instructor is expected to facilitate self-discovery and self-critique by the crew. We have recently completed a study in which we observed 36 LOFT briefings at 5 major U.S. airlines. We audiotape recorded the briefings, transcribed the recordings, and coded for more than 70 variables. Our analysis addresses four broad questions: To what extent do instructors attempt to facilitate crew self-analysis? What techniques do instructors use to facilitate and how effective are these techniques? What is the character of crew participation? To what extent do briefings emphasize CRM and crew performance? We discuss the implications of our findings for ALP and LOE.

Dismukes, Key↗
DOE OSTI2022

Differential methods for assessing sensitivity in biological models

Differential sensitivity analysis is indispensable in fitting parameters, understanding uncertainty, and forecasting the results of both thought and lab experiments. Although there are many methods currently available for performing differential sensitivity analysis of biological models, it can be difficult to determine which method is best suited for a particular model. In this paper, we explain a variety of differential sensitivity methods and assess their value in some typical biological models. First, we explain the mathematical basis for three numerical methods: adjoint sensitivity analysis, complex perturbation sensitivity analysis, and forward mode sensitivity analysis. We then carry out four instructive case studies. (a) The CARRGO model for tumor-immune interaction highlights the additional information that differential sensitivity analysis provides beyond traditional naive sensitivity methods, (b) the deterministic SIR model demonstrates the value of using second-order sensitivity in refining model predictions, (c) the stochastic SIR model shows how differential sensitivity can be attacked in stochastic modeling, and (d) a discrete birth-death-migration model illustrates how the complex perturbation method of differential sensitivity can be generalized to a broader range of biological models. Finally, we compare the speed, accuracy, and ease of use of these methods. We find that forward mode automatic differentiation has the quickest computational time, while the complex perturbation method is the simplest to implement and the most generalizable.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1986

Synthesis and analysis in studies of chemical evolution

Studies of the various processes that may have given rise to life on the Earth have demonstrated the appropriateness of an approach that makes use of analysis and synthesis. Analysis of extraterrestrial samples in the form of meteorites has demonstrated the presence of several precursors of biomolecules, most notably a full suite of nucleic acid bases and nucleotides of biological significance. These species were determined after exhaustive extraction of the sample and subsequent analysis using HPLC, GC, MS, and GC-MS. Procedural blanks indicate that these molecules are likely not the result of contamination during the extraction and analysis process. Similar species were found as products of spark discharge experiments in atmospheres thought to mimic primitive Earth conditions. These results indicate that the basic chemistry underlying these syntheses is common, and that life may not be unique to the Earth. Studies underway in the laboratory make use of proton nuclear magnetic resonance spectroscopy as a probe to assess associations between selected amino acids and any of several nucleotides comprising their genetic code and genetic anticode sequences. These studies demonstrate a clear selectivity by the anticode sequences, thus confirming the hydrophobicity studies performed by Lacey et al. These studies further support the contention that life is likely a natural result of the physics and chemistry of the universe.

Ponnamperuma, C.↗
NASA NTRS1989

A study of material damping in large space structures

A constitutive model was developed for predicting damping as a function of damage in continuous fiber reinforced laminated composites. The damage model is a continuum formulation, and uses internal state variables to quantify damage and its subsequent effect on material response. The model is sensitive to the stacking sequence of the laminate. Given appropriate baseline data from unidirectional material, and damping as a function of damage in one crossply laminate, damage can be predicted as a function of damage in other crossply laminates. Agreement between theory and experiment was quite good. A micromechanics model was also developed for examining the influence of damage on damping. This model explicitly includes crack surfaces. The model provides reasonable predictions of bending stiffness as a function of damage. Damping predictions are not in agreement with the experiment. This is thought to be a result of dissipation mechanisms such as friction, which are not presently included in the analysis.

Highsmith, A. L.↗
NASA NTRS1991

A review of radio interferometric imaging of comets

An overview of cometary observations carried out with the VLA which include OH imaging observations, studies of other molecules, and searches for continuum emission, is presented. Attention is focussed on the OH observations obtained of Comet Halley, a periodic comet, and Comet Wilson, a 'new' comet. The emission from Comet Halley is confined to a region a few times 10 exp 5 km. The emission from Comet Wilson exhibits sporadic blobs at large distances (about 10 exp 6 from the center), which vary abruptly in both position and velocity. It is suggested that for Comet Halley, collisional effects near the edge of the quenching region, which is coincidentally the approximate distance to the cometopause, may be important, and that for Comet Wilson, outgassing from cometesimals ejected from the nucleus may be significant. It is shown that asymmetric line profiles are more common than previously thought. H2CO detection experiments for comets Halley and Machholz are summarized.

De Pater, Imke↗
NASA NTRS2002

STS-112 Crew Interviews - Wolf

STS-112 Mission Specialist David Wolf is seen during this preflight interview, where he first answers questions on his career path and role models. Other questions cover mission goals, ISS (International Space Station) Expedition 5 spacecrew, crew training, the S1 Truss and its radiators, the MBS (Mobile Base Structure), his experience onboard Mir, and his EVAs (extravehicular activities) on the coming mission. The EVAs are the subject of several questions. Wolf discusses his crew members, and elsewhere discusses Pilot Pamela Melroy's role as an IV crew member during EVAs. In addition, Wolf answers questions on transfer operations, the SHIMMER experiment, and his thoughts on multinational crews and crew bonding.

Source record↗
NASA NTRS2008

The Costs of Knowledge

Acquiring knowledge-genuinely learning something new-requires the consent and commitment of the person you're trying to learn from. In contrast to information, which can usually be effectively transmitted in a document or diagram, knowledge comes from explaining, clarifying, questioning, and sometimes actually working together. Getting this kind of attention and commitment often involves some form of negotiation, since even the most generous person's time and energy are limited. Few experts sit around waiting to share their knowledge with strangers or casual acquaintances. In reasonably collaborative enterprises- I think NASA is one-this sort of negotiation isn't too onerous. People want to help each other and share what they know, so the "cost" of acquiring knowledge is relatively low. In many organizations (and many communities and countries), however, there are considerable costs associated with this activity, and many situations in which negotiations fail. The greatest knowledge cost is in and adopting knowledge to one's own use. Sometimes this means formally organizing what one learns in writing. Sometimes it means just taking time to reflect on someone else's thoughts and experiences-thinking about knowledge that is not exactly what you need but can lead you to develop ideas that will be useful. A long, discursive conversation, with all the back-and-forth that defines conversation, can be a mechanism of knowledge exchange. I have seen many participants at NASA APPEL Masters Forums talking, reflecting, and thinking-adapting what they are hearing to their own needs. Knowledge transfer is not a simple proposition. An enormous amount of information flows through the world every day, but knowledge is local, contextual, and "stickyn-that is, it takes real effort to move it from one place to another. There is no way around this. To really learn a subject, you have to work at it, you have to pay your "knowledge dues." So while, thanks to advances in technology, almost infinite amounts of information are instantly available, it still takes the same amount of time and work to learn French as it did in the year 1800-or to master physics or philosophy.

Prusak, Laurence↗
NASA NTRS1991

Lessons learned and their application to program development and cultural issues

The knowledge used today is contained in an untold number of technical and managerial handbooks. This knowledge is derived from the known strengths and weaknesses experienced during the execution of programs and projects that are being used today. The purpose is to stir up thought, not on specific experiences, but on implementation of lessons learned from these experiences.

Roth, Gilbert L.↗
NASA NTRSDate not supplied

Present Day Volcanism on Venus: Evidence from Alteration Experiments

The crust of Venus is thought to be comprised of basaltic rocks with similar composition to terrestrial volcanics, but on Venus they are in contact with a hot caustic atmosphere that should alter them to produce weathering rinds. These weathering rinds should affect orbital measurements (both radar and spectroscopy) of the crust, such has been measured at Idunn Mons. However, the rate of alteration on Venus and specifically how alteration mineralogy affects orbital measurements are not well understood. With the upcoming decade of Venus exploration, laboratory measurements connecting alteration and spectroscopy are critically needed. Here, I will summarize what is known about the composition of Venus lava flows and the rate at which these rocks should alter on the Venus surface. I will then apply this work to Idunn Mons as a case study to show that it should be volcanically active, which may be detectable by the pcoming fleet of missions.

Justin Filiberto↗
NASA NTRS2016

Investigating the Simulink Auto-Coding Process

Model based program design is the most clear and direct way to develop algorithms and programs for interfacing with hardware. While coding "by hand" results in a more tailored product, the ever-growing size and complexity of modern-day applications can cause the project work load to quickly become unreasonable for one programmer. This has generally been addressed by splitting the product into separate modules to allow multiple developers to work in parallel on the same project, however this introduces new potentials for errors in the process. The fluidity, reliability and robustness of the code relies on the abilities of the programmers to communicate their methods to one another; furthermore, multiple programmers invites multiple potentially differing coding styles into the same product, which can cause a loss of readability or even module incompatibility. Fortunately, Mathworks has implemented an auto-coding feature that allows programmers to design their algorithms through the use of models and diagrams in the graphical programming environment Simulink, allowing the designer to visually determine what the hardware is to do. From here, the auto-coding feature handles converting the project into another programming language. This type of approach allows the designer to clearly see how the software will be directing the hardware without the need to try and interpret large amounts of code. In addition, it speeds up the programming process, minimizing the amount of man-hours spent on a single project, thus reducing the chance of human error as well as project turnover time. One such project that has benefited from the auto-coding procedure is Ramses, a portion of the GNC flight software on-board Orion that has been implemented primarily in Simulink. Currently, however, auto-coding Ramses into C++ requires 5 hours of code generation time. This causes issues if the tool ever needs to be debugged, as this code generation will need to occur with each edit to any part of the program; additionally, this is lost time that could be spent testing and analyzing the code. This is one of the more prominent issues with the auto-coding process, and while much information is available with regard to optimizing Simulink designs to produce efficient and reliable C++ code, not much research has been made public on how to reduce the code generation time. It is of interest to develop some insight as to what causes code generation times to be so significant, and determine if there are architecture guidelines or a desirable auto-coding configuration set to assist in streamlining this step of the design process for particular applications. To address the issue at hand, the Simulink coder was studied at a foundational level. For each different component type made available by the software, the features, auto-code generation time, and the format of the generated code were analyzed and documented. Tools were developed and documented to expedite these studies, particularly in the area of automating sequential builds to ensure accurate data was obtained. Next, the Ramses model was examined in an attempt to determine the composition and the types of technologies used in the model. This enabled the development of a model that uses similar technologies, but takes a fraction of the time to auto-code to reduce the turnaround time for experimentation. Lastly, the model was used to run a wide array of experiments and collect data to obtain knowledge about where to search for bottlenecks in the Ramses model. The resulting contributions of the overall effort consist of an experimental model for further investigation into the subject, as well as several automation tools to assist in analyzing the model, and a reference document offering insight to the auto-coding process, including documentation of the tools used in the model analysis, data illustrating some potential problem areas in the auto-coding process, and recommendations on areas or practices in the current Ramses model that should be further investigated. Several skills were required to be built up over the course of the internship project. First and foremost, my Simulink skills have improved drastically, as much of my experience had been modeling electronic circuits as opposed to software models. Furthermore, I am now comfortable working with the Simulink Auto-coder, a tool I had never used until this summer; this tool also tested my critical thinking and C++ knowledge as I had to interpret the C++ code it was generating and attempt to understand how the Simulink model affected the generated code. I had come into the internship with a solid understanding of Matlab code, but had done very little in using it to automate tasks, particularly Simulink tasks; along the same lines, I had rarely used shell script to automate and interface with programs, which I gained a fair amount of experience with this summer, including how to use regular expression. Lastly, soft-skills are an area everyone can continuously improve on; having never worked with NASA engineers, which to me seem to be a completely different breed than what I am used to (commercial electronic engineers), I learned to utilize the wealth of knowledge present at JSC. I wish I had come into the internship knowing exactly how helpful everyone in my branch would be, as I would have picked up on this sooner. I hope that having gained such a strong foundation in Simulink over this summer will open the opportunity to return to work on this project, or potentially other opportunities within the division. The idea of leaving a project I devoted ten weeks to is a hard one to cope with, so having the chance to pick up where I left off sounds appealing; alternatively, I am interested to see if there are any opening in the future that would allow me to work on a project that is more in-line with my research in estimation algorithms. Regardless, this summer has been a milestone in my professional career, and I hope this has started a long-term relationship between JSC and myself. I really enjoy the thought of building on my experience here over future summers while I work to complete my PhD at Missouri University of Science and Technology.

Gualdoni, Matthew J.↗
DOE OSTI2025

Gravitational wave detection with plasma haloscopes

Searches for high frequency gravitational waves using cavities based on the Gertsenshtein effect were recently proposed, building off existing axion dark matter experiments. In particular, the sensitivity of axion dark matter experiments using metamaterial plasmas (tunable plasma haloscopes) to gravitational waves has not been explored in detail. Here we perform a full analysis of gravitational wave detection in plasma haloscopes, showing that the baseline design of experiments such as ALPHA is several orders of magnitude less sensitive than previously thought. We show how simple changes to the experiment can recover that sensitivity and lead to a powerful gravitational wave detector in the 𝒪⁡(10–50) GHz frequency range.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
NASA NTRS1993

Satiation or availability? Effects of attention, memory, and imagery on the perception of ambiguous figures

The prolonged-inspection technique has been used to demonstrate effects of satiation on the perception of ambiguous figures. We propose that the inspection phase, in which subjects view an unambiguous version of the stimulus prior to observing the ambiguous figure, does not create neural fatigue but rather provides a context in which the alternative percept is apprehended and gains perceptual strength through processes such as imagination or memory. The consequent availability of the alternative organization drives the perceptual phenomena that have been thought to reflect satiation. In Experiment 1, we demonstrated that (1) preexperimental exposure to the target figures and (2) allocation of attention to the inspection figures were both necessary in order to obtain results similar to those predicted by the satiation model. In Experiment 2, we obtained similar results, finding that effects of prior inspection were greater the greater the amount and availability of information regarding the alternative percept during the inspection phase. Subjects who generated visual images of the noninspected alternative during inspection yielded results comparable to those from subjects to whom both versions were presented visually.

Horlitz, Krista L.↗
NASA NTRS1996

Building Satellites is Easier

'Building Satellites' is a story about Jim Marsh's recovery from a severe head injury told by his wife Phyllis from the moment she learned of its happening, through the ups and downs of a lengthy rehabilitation, until his return to work and daily living. It continues on, however, and narrates his battle with the more insidious Grave's disease. Told in the first person, 'Building Satellites' vividly portrays Phyllis's thoughts and feelings throughout this experience with scrupulous honestly. This is a story worth reading for many reasons. First of all, Jim was an accomplished scientist, respected by his colleagues both in this country and abroad. Secondly, it narrates the many stages of his recovery from head injury with detailed readable accuracy; it informs us as well as inspires. Finally, 'Building Satellites" also tells us the story of Phyllis Marsh's remarkable creative response to this crisis. It narrates her personal experiences as she progresses through the strange and somewhat bizarre world of medicine and rehabilitation, guided by a few basic beliefs, which she learned as a child in Iowa, that provided her with the strength to endure. 'Building Satellites' seems to reaffirm our unconscious, but settled conviction, that when confornted overnight with adversity, we are somehow given the means for coping, supported by our basic beliefs, strengthened by family and friends, and eventually learning to accept any outcome.

Marsh, Phyllis Nimmo↗
NASA NTRS2003

Expedition 7 Crew Interview: Yuri Malenchenko

Cosmonaut Yuri Malenchenko of Expedition Seven is seen during a pre-launch interview. He begins by telling why he wanted to become a cosmonaut. Malenchenko expresses his reaction about the news of the Space Shuttle Columbia accident, and how this mission will be different from other missions. He also expresses the challenges that face Malenchenko and Ed Lu such as the crew reduction from three to two, less supplies and no space shuttle flights. Malenchenko says that he will have to work on a compressed schedule, which will make the mission even more challenging. A description of the handover of Expedition Six is given. Malenchenko and Ed Lu will be cramped in a confined space on the Soyuz Spacecraft for two days before docking, and he talks about this experience. Lastly, Malenchenko gives his thoughts on how it will be to work with Ed Lu in space, and tells of Lu's trustworthiness and reliability as a fellow crew member.

Source record↗