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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 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
NASA NTRS1994

An incremental database access method for autonomous interoperable databases

We investigated a number of design and performance issues of interoperable database management systems (DBMS's). The major results of our investigation were obtained in the areas of client-server database architectures for heterogeneous DBMS's, incremental computation models, buffer management techniques, and query optimization. We finished a prototype of an advanced client-server workstation-based DBMS which allows access to multiple heterogeneous commercial DBMS's. Experiments and simulations were then run to compare its performance with the standard client-server architectures. The focus of this research was on adaptive optimization methods of heterogeneous database systems. Adaptive buffer management accounts for the random and object-oriented access methods for which no known characterization of the access patterns exists. Adaptive query optimization means that value distributions and selectives, which play the most significant role in query plan evaluation, are continuously refined to reflect the actual values as opposed to static ones that are computed off-line. Query feedback is a concept that was first introduced to the literature by our group. We employed query feedback for both adaptive buffer management and for computing value distributions and selectivities. For adaptive buffer management, we use the page faults of prior executions to achieve more 'informed' management decisions. For the estimation of the distributions of the selectivities, we use curve-fitting techniques, such as least squares and splines, for regressing on these values.

Roussopoulos, Nicholas↗
NASA NTRS1995

CFD Data Sets on the WWW for Education and Testing

The Numerical Aerodynamic Simulation (NAS) Systems Division at NASA Ames Research Center has begun the development of a Computational Fluid Dynamics (CFD) data set archive on the World Wide Web (WWW) at URL http://www.nas.nasa.gov/NAS/DataSets/. Data sets are integrated with related information such as research papers, metadata, visualizations, etc. In this paper, four classes of users are identified and discussed: students, visualization developers, CFD practitioners, and management. Bandwidth and security issues are briefly reviewed and the status of the archive as of May 1995 is examined. Routine network distribution of data sets is likely to have profound implications for the conduct of science. The exact nature of these changes is subject to speculation, but the ability for anyone to examine the data, in addition to the investigator's analysis, may well play an important role in the future.

Globus, Al↗
NASA NTRS2003

ASK Magazine

Academy of Program and Project Leadership (APPL) and ASK Magazine helps NASA managers and project teams accomplish today's missions and meet tomorrow's challenges by providing performance enhancement services and tools, supporting career development programs, sponsoring knowledge sharing events and publications, and creating opportunities for project management collaboration with universities, professional associations, industry partners, and other government agencies. ASK Magazine grew out of APPL's Knowledge Sharing Initiative. The stories that appear in ASK are written by the best of the best project managers, primarily from NASA, but also from other government agencies and industry. These stories contain genuine nuggets of knowledge and wisdom that are transferable across projects. Who better than a project manager to help another project manager address a critical issue on a project? Big projects, small projects - they're all here in ASK. Please direct all inquiries about ASK Magazine editorial policy to Todd Post, EduTech Ltd., 8455 Colesville Rd., Suite 930, Silver Spring, MD 20910, (301) 585-1030; or email to tpost@edutechltd.com.

Laufer, Alexander↗
NASA NTRS2002

Automated fault-management in a simulated spaceflight micro-world

BACKGROUND: As human spaceflight missions extend in duration and distance from Earth, a self-sufficient crew will bear far greater onboard responsibility and authority for mission success. This will increase the need for automated fault management (FM). Human factors issues in the use of such systems include maintenance of cognitive skill, situational awareness (SA), trust in automation, and workload. This study examine the human performance consequences of operator use of intelligent FM support in interaction with an autonomous, space-related, atmospheric control system. METHODS: An expert system representing a model-base reasoning agent supported operators at a low level of automation (LOA) by a computerized fault finding guide, at a medium LOA by an automated diagnosis and recovery advisory, and at a high LOA by automate diagnosis and recovery implementation, subject to operator approval or veto. Ten percent of the experimental trials involved complete failure of FM support. RESULTS: Benefits of automation were reflected in more accurate diagnoses, shorter fault identification time, and reduced subjective operator workload. Unexpectedly, fault identification times deteriorated more at the medium than at the high LOA during automation failure. Analyses of information sampling behavior showed that offloading operators from recovery implementation during reliable automation enabled operators at high LOA to engage in fault assessment activities CONCLUSIONS: The potential threat to SA imposed by high-level automation, in which decision advisories are automatically generated, need not inevitably be counteracted by choosing a lower LOA. Instead, freeing operator cognitive resources by automatic implementation of recover plans at a higher LOA can promote better fault comprehension, so long as the automation interface is designed to support efficient information sampling.

NASA Discipline Space Human Factors↗
NASA NTRS2004

Human Missions to Europa and Titan - Why Not?

This report describes a long-term development plan to enable human exploration of the outer solar system, with a focus on Europa and Titan. These are two of the most interesting moons of Jupiter and Saturn, respectively, because they are the places in the solar system with the greatest potential for harboring extraterrestrial life. Since human expeditions to these worlds are considered impossible with current capabilities, the proposal of a well-organized sequence of steps towards making this a reality was formulated. The proposed Development Plan, entitled Theseus, is the outcome of a recent multinational study by a group of students in the framework of the Master of Space Studies (MSS) 2004 course at the International Space University (ISU). The Theseus Program includes the necessary development strategies in key scientific and technological areas that are essential for identifying the requirements for the exploration of the outer planetary moons. Some of the topics that are analysed throughout the plan include: scientific observations at Europa and Titan, advanced propulsion and nuclear power systems, in-situ resource utilization, radiation mitigation techniques, closed life support systems, habitation for long-term spaceflight, and artificial gravity. In addition to the scientific and technological aspects of the Theseus Program, it was recognized that before any research and development work may begin, some level of program management must be established. Within this chapter, legal issues, national and international policy, motivation, organization and management, economic considerations, outreach, education, ethics, and social implications are all considered with respect to four possible future scenarios which enable human missions to the outer solar system. The final chapter of the report builds upon the foundations set by Theseus through a case study. This study illustrates how such accomplishments could influence a mission to Europa to search for evidence of life in its subsurface oceans. The future remains unpredictable, as does the realization of any of these possibilities. However, projects such as this remind us that the final frontier for humans is truly outer space, and only our imagination will determine where the frontier stops. We can dream of visiting other planetary systems and perhaps even galaxies, but we must begin closer, and considering the scope of our known universe, Europa and Titan are very close indeed.

FROM↗
NASA NTRS2009

Inter-agency Working Group for Airborne Data and Telemetry Systems (IWGADTS)

The Interagency Coordinating Committee for Airborne Geosciences Research and Applications (ICCAGRA) was established to improve cooperation and communication among agencies sponsoring airborne platforms and instruments for research and applications, and to serve as a resource for senior level management on airborne geosciences issues. The Interagency Working Group for Airborne Data and Telecommunications Systems (IWGADTS) is a subgroup to ICCAGRA for the purpose of developing recommendations leading to increased interoperability among airborne platforms and instrument payloads, producing increased synergy among research programs with similar goals, and enabling the suborbital layer of the Global Earth Observing System of Systems.

Webster, Chris↗
NASA NTRS2009

From Research to Flight: Surviving the TRL Valley of Death for Robotic and Human Space Exploration

There must be a plan or opportunities for flight validation: a) To reduce the bottleneck of new technologies at the TRL Valley of Death; b) To allow frequent infusion of new technologies into flight missions. Risk must be tolerated for new technology flight experiments. Risk must also be accepted on early-adopting missions to enable new capabilities. Fundamental research is critical to taking the next giant leap in the scientific exploration of space. Technology push is often required to meet current mission requirements. Technology management requires more than issuing NRAs and overseeing contracts.

Johnson, Les↗
NASA NTRS2009

From Research to Flight: Surviving the TRL Valley of Death for Robotic and Human Exploration

Fundamental research is critical to taking the next giant leap in the scientific exploration of space. NASA should be pushing the envelope and asking "what if?" .. Technology push enables new capabilities. When NASA began, everything was enabling. .. Technology pull is often required to meet current mission requirements. Technology management requires more than issuing NRAs and overseeing contracts. Continuous assessment, peer review, and system systems studies are vital to credible TRL advancement. A strategy for taking technology R&D to new heights will lead to discoveries at far-reaching destinations..

Johnson, Les↗
NASA NTRS2008

Estimating the Reliability of Electronic Parts in High Radiation Fields

Radiation effects on materials and electronic parts constrain the lifetime of flight systems visiting Europa. Understanding mission lifetime limits is critical to the design and planning of such a mission. Therefore, the operational aspects of radiation dose are a mission success issue. To predict and manage mission lifetime in a high radiation environment, system engineers need capable tools to trade radiation design choices against system design and reliability, and science achievements. Conventional tools and approaches provided past missions with conservative designs without the ability to predict their lifetime beyond the baseline mission.This paper describes a more systematic approach to understanding spacecraft design margin, allowing better prediction of spacecraft lifetime. This is possible because of newly available electronic parts radiation effects statistics and an enhanced spacecraft system reliability methodology. This new approach can be used in conjunction with traditional approaches for mission design. This paper describes the fundamentals of the new methodology.

radiation↗
NASA NTRS2018

Radar Measurements of the LEO Orbital Debris Environment

Access to space and the preservation of the near-Earth space environment is of critical significance. Increased interest in issues surrounding space traffic management and the continued assessment and discussion of orbital debris at the United Nations Committee on the Peaceful Uses of Outer Space (COPUOS) illustrates the significance of the topic of orbital debris. There are currently over 20,000 tracked objects in the publicly available satellite catalog on Space-Track.org. The catalog is maintained by the US Air Force Space Command using a network of optical and radar ground-based sensors and is believed to be complete for a characteristic size of 10 cm or larger in low Earth orbit (LEO). Based on the work of the NASA Orbital Debris Program Office (ODPO) over approximately the past 40 years it is understood that the small debris population (< 10 cm) increases by orders of magnitude as characteristic size decreases. With population estimates ranging from 500,000 to 1,000,000 small debris objects (> 5 mm) in orbit, it is currently not practical to track and maintain precision orbits on every object. Instead the NASA ODPO uses powerful ground-based radars to sample the low Earth Orbit (LEO) environment and assign approximate orbits to each detection. This poses an interesting signal processing challenge as we are trying to detect the smallest objects possible on the edge of the radar's sensitivity. For approximately the last 30 years, NASA ODPO has partnered with the Massachusetts Institute of Technology Lincoln Laboratory (MIT/LL) to utilize the Haystack Ultra-wideband Satellite Imaging Radar (HUSIR - formerly the Long-Range Imaging Radar or simply Haystack) and the Haystack Auxiliary (HAX) radar to collect orbital debris radar data. Additionally, the ODPO collaborates with the NASA Jet Propulsion Laboratory (JPL) to use the Goldstone Solar System Radar. The orbital debris detections from these radars serve as inputs for statistical risk models used by the human spaceflight and satellite communities to assess risk to spacecraft posed by orbital debris. In this paper, we will describe the history of orbital debris radar measurements conducted by NASA, provide an overview of current radar measurements techniques and facilities, discuss the signal processing software used for orbital debris measurements and the inference of debris size and orbital parameters from these measurements, and discuss how orbital debris radar measurements are validated for use in models that are used throughout the aerospace industry.

Blackwell, Chris↗
NASA NTRS2016

Thirsty Walls: A New Paradigm for Air Revitalization in Life Support

This Phase I project Summary will be formatted as a series of summary statements, with additional comments. The summary statements are intended to focus on the most significant findings and discoveries – things that the project team knows now, but we didn’t know at the beginning of the project: 1) Direct Contact Between Gases is an ECLS (Environmental Control and Life Support) System enabling capability; 2) CO2 capture using liquid sorbents in microgravity is feasible; 3) There are other ways to contact gases and liquids – but thin film capillary techniques are new, exciting, and have amazing potential; 4) ECLS system reliability is the key to exploration missions – the key to reliability is having system attributes that favor reliability; 5) The processes with favorable reliability attributes tend to be biological; 6) The single greatest impact on launch mass of an ECLS system is water. The best way to enable biological water processing is to develop a capillary based method of urine capture that doesn’t use pretreat chemicals; 7) There is good, promising, forward design and development work – but no fundamental “show stoppers” – to develop a thin film liquid sorbent CO2 capture system; 8) The most capable Ionic Liquids are not presently feasible, but other chemically active liquids can be used to make an effective thin film CO2 capture device; 9) The C9 reduced gravity flight showed feasibility – and taught us about flow instability issues; 10) Capillary fluid management has ECLS system wide implications.

CO2↗
NASA NTRS2022

Flood Monitoring Using Enhanced Resolution Passive Microwave Data: A Test Case Over Bangladesh

Monitoring floods is a major issue in water resources management and risk mitigation, especially in the Global South. Optical and radar observations, even providing a fine spatial resolution, are still limited by cloud cover interaction or insufficient temporal resolution. On the other hand, passive microwave (PMW) sensors collect information on a daily frequency with minor cloud cover interaction, but they have been historically limited in terms of spatial resolution. Here, we evaluate the capability of an enhanced spatial resolution PMW dataset (3.125 km) in monitoring spatio-temporal evolution of flood events, focusing on a major flood event that occurred in October 2005 in Bangladesh. We apply an algorithm aimed to remove the seasonal variability of surface temperature from the PMW timeseries, exploiting the difference in emissivity between dry and water-covered pixels. We assess the capability of the algorithm in capturing flood evolution and extension through the comparison with quantities obtained from optical data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) and water level measurements. We also compare the enhanced product with the historical coarser resolution dataset by means of a variogram-based analysis to evaluate the improvements in terms of spatial representation. Finally, we evaluate the possibility to extract the water fraction within a single pixel by using an Advanced Microwave Scanning Radiometer—Earth Observing System (AMSR-E) emissivity dataset and compare the estimates with MODIS-derived water fractions. Our results show that the enhanced PMW product outperforms the coarser one when compared to flood mapped from optical data based on information content, indicating that it is possible to integrate such a product into the mapping of floods at a global scale on a daily basis.

flood detection↗
DOE OSTI2021

Data Driven Analysis for Modernization Program Management

NNSA is responsible for managing national nuclear security missions: ensuring a safe, secure, and reliable nuclear deterrent; supplying nuclear fuel to the Navy; and supporting the nation’s nuclear nonproliferation efforts. However, over half of NNSA’s facilities are more than 40 years old, and roughly one-third date back to the Manhattan Project. To execute its critical nuclear security missions, NNSA is making large investments to modernize its nuclear production capabilities. This ramp up represents NNSA’s largest modernization effort since the Cold War. Given the scale of these efforts, NNSA’s Office of Secondary Stage Production Modernization has implemented data driven techniques to prioritize investments and inform strategic decision making. NNSA, with support from its site managing contractors, has developed and implemented an integrated schedule and risk management system to address the issues and limitations with the traditional approach. The multi-year integrated schedules are key to identifying program linkages and managing large portfolios comprised of many different projects and efforts. In conjunction with the integrated schedule, a new program risk management system has also been developed and implemented, which manages program risks and opportunities, along with specific mitigation strategies to reduce or eliminate the risks per timelines that are tracked in the integrated schedule. This paper is supplemented with a follow-on presentation on effective management of program material and throughput modeling.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2022

Secure Control Regions for Distributed Stochastic Systems with Application to Distributed Energy Resource Dispatch: Preprint

With the increasing connectedness and interdependence of systems that are stochastic in nature, the issue of how to manage and coordinate them for safe operation has evidently become more important. In many networked system architectures, the system-wide output has to be delicately managed; often within a prescribed set of bounds. In this paper, a novel control framework is proposed where the bounds on the outputs are translated into independent bounds on the controllable inputs of each subsystem. The main benefit of this framework is that respecting the individual control bounds suffices to guarantee that the system-wide outputs will remain within safe boundaries. Since the systems are assumed to be stochastic, the bounds on the output are introduced as probabilistic chance constraints. The benefits of this framework are demonstrated by applying it to the control of distributed energy resources in a distribution networks where main goal is to keep the voltage magnitudes with their prescribed bounds. The control bounds are evaluated using real data on an IEEE test system.

chance constrained optimization↗
DOE OSTI2022

Federal Energy Savings Performance Contracts Frequently Asked Questions on the Scope of 42 U.S.C. § 8287 et. seq.

The U.S. Department of Energy's Federal Energy Management Program (FEMP) is issuing this document to provide clarifications and guidance on issues commonly raised regarding the scope of 42 U.S.C. § 8287 et seq. This document is intended to supplement FEMP's extensive collection of materials that are available to assist federal agencies execute successful energy savings performance contracting (ESPC) projects.

42 U.S.C. § 8287 et. seq.↗
DOE OSTI2020

Panel Session 1: WMS 2020 Plenary Session

The plenary panel focused on government and industry world leaders speaking on the pressing issues facing radioactive waste management in 2020 and beyond. Panelists included an OECD/ NEA representative for the international community, a Huntington Ingalls Industries representative for the commercial sector, and the US DOE Senior Advisor to the Under Secretary of Science representing DOE Environmental Management. Panelists with presentations: WM2020 Speech (Michael Lempke); Optimization: A Better Path toward Managing Nuclear Decommissioning and Legacies (William Magwood); Update On the DOE Environmental Management Program (William White)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

A template of information needs for decision-making about delaying remediation on contaminated lands to protect human health

The contamination legacy of industrialization, militarization, and nuclear arms race poses current or future risks to populations and the environment. Responsible parties and regulators make decisions regarding which sites to clean up, how, how much, and when. This study aimed to provide an information needs template to evaluate and reduce risks to human health when considering whether to initiate or delay remediation. This investigation focused on four aspects of timing and prioritization: 1) management, planning and implementation, 2) source terms, pathways, and exposures, 3) risks and receptors, and 4) external drivers. Within each type, issues were identified and described. Management class included personnel, health and safety data, funding, equipment, and structural integrity. Source term included contaminant sources, pathways, initiating events, and barriers to exposure. Risk included types and exposures to workers and general public. External drivers included regulatory framework, stakeholders, Congressional mandates, and economic and social contexts. Risk may increase over time as contamination spreads, enters aquifers, and reaches receptors, and may decline as radionuclides decay, and plumes dissipate. The overall objective was to provide a template of information that is useful to managers and regulators, and might be used by the public to understand the risks and benefits of re-prioritization cleanup.

Environmental Sciences & Ecology↗