SEARCH · Engineering Papers

Results for “assets”

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.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 613 records · Page 34

All sources NASA NTRS DOE OSTI

DOE OSTI2026

EXERGETIC: De-Risking Next-Generation Resilient Geothermal Hybrids via At-Scale Evaluation Using Virtual Emulation Digital Twin Environment for Efficient Operation

The DOE-GTO-funded project, award number 5.1.2.12, entitled "EXERGETIC - De-risking Next Generation Resilient Geothermal Hybrids via at-Scale Evaluation Using a Virtual Emulation Digital Twin Environment for Efficient Operation," advances the solution to these challenges by developing and validating a geothermal co-emulation environment implemented at the National Laboratory of the Rockies (NLR)'s Advanced Research on Integrated Energy Systems (ARIES) platform. This framework enables the de-risking of next-generation geothermal and geothermal hybrid systems through high-fidelity modeling, real-time digital emulation, advanced control strategies, and techno-economic assessment. The project focused on geothermal hybrid configurations that integrate geothermal power plants with concentrated solar power and underground thermal energy storage, enabling enhanced efficiency, flexibility, and grid support capabilities. The main goal of this project was the development of a geothermal digital co-emulation environment to demonstrate the technical and economic value of geothermal hybrid systems and their contribution to grid stability and flexibility. The EXERGETIC framework combined physics-based models, controls, and real assets at ARIES, including digital real-time simulators (DRTS), a 20-MW-scale controllable grid interface (CGI), and a 2-MW conventional generator. Detailed transient models were developed for the key subsystems of a hybrid geothermal plant, including parabolic trough solar collectors, reservoir thermal energy storage (RTES), and a binary Organic Rankine Cycle (ORC) power plant. The ORC model explicitly captured thermal inertia and off-design operation and integrated control strategies to dynamically respond to electric load profiles. The models were validated against published experimental and numerical studies, demonstrating strong agreement and confirming the accuracy and robustness of the modeling approach. The resulting digital twin represents geothermal-solar-storage systems at multiple scales (1 MW to 100 MW) and enables realistic emulation of grid-connected operation. The control architecture allows the geothermal resource to provide stable baseload generation, while solar and stored thermal energy supply flexible, dispatchable support during periods of high demand or variable grid conditions. A key contribution of the EXERGETIC project is the demonstration that geothermal hybrid systems can be designed to be active grid assets rather than passive baseload generators. Using the ARIES platform, the digital twin was evaluated under multiple grid scenarios, including load following, voltage support at the distribution level, and frequency response at the transmission level. Results show that hybrid geothermal systems can respond effectively to dynamic grid conditions, providing inertia-like behavior, primary frequency support, and voltage regulation through coordinated control. In addition to the performance and grid services capability analysis of geothermal and hybrid geothermal systems, the EXERGETIC project also focused on scalability and techno-economic analysis of geothermal hybrid plants. In particular, for the scalability analysis, machine-learning (ML)-based surrogate models were trained using data generated from the geothermal digital twin under different grid-connected scenarios and plant capacities. These ML models demonstrated strong interpolation and extrapolation capabilities across plant sizes, accurately reproducing both steady-state and transient responses with very low errors. Regarding the techno-economic analysis, plant performance results were integrated with cost models for hybrid geothermal systems, and the levelized cost of electricity (LCOE) was used as the main economic metric to evaluate system performance across a range of system capacities, solar shares, solar multiples, and storage durations. Results indicate that economies of scale significantly reduce geothermal LCOE as plant capacity increases, with large-scale systems (25-100 MW) achieving substantially lower costs than small plants. Hybridization with solar thermal energy and storage further improves economic performance by increasing capacity utilization and enabling flexible dispatch. In addition, thermal storage plays a critical role in reducing LCOE by maximizing geothermal, solar, and stored energy resources. In summary, the results from this project demonstrate that geothermal hybrid systems represent a promising alternative for increasing the energy conversion efficiency of geothermal technologies, contributing to the preservation of geothermal resources, and supporting the transition of geothermal plants from traditional baseload resources into flexible, resilient, and cost-competitive energy conversion technologies.

15 GEOTHERMAL ENERGY↗

DOE OSTI2021

Long-run Marginal CO2 Emission Rates Workbooks for 2020 Standard Scenarios Cambium Data

This dataset has been superseded by a new set of workbooks that can be found here: https://data.nlr.gov/submissions/183 These workbooks contain modeled estimates of long-run marginal CO2 emission rates (LRMER) for the contiguous United States. The LRMER is an estimate of the rate of emissions that would be either induced or avoided by a long-term (i.e., more than several years) change in electrical demand. It incorporates both the projected changes to the electric grid, as well as the potential for an incremental change in electrical demand to influence the structural evolution of the grid (i.e., the building and retiring of capital assets, such as generators and transmission lines). It is therefore distinct from the more-commonly-known short-run marginal, which treats grid assets as fixed. In addition to year-over-year data, the Levelized LRMER worksheet within each workbook is set up to produce a levelized long-run marginal emission rate based on user-provided inputs. These levelized LRMER values are intended for analysts to use when estimating the emissions induced (or avoided) by a long-term change in end-use electricity demand. Three future scenarios are provided in separate workbooks: A Mid-case (i.e., business-as-usual), and two scenarios with relatively higher or lower renewable energy costs. For more details on these scenarios, see the Standard Scenarios 2020 Report ( https://www.nlr.gov/docs/fy21osti/77442.pdf ). For more data underlying each scenario, see the Standard Scenarios 2020 project (Cambium data) at https://cambium.nlr.gov/ . This data was produced as part of the Cambium project. For more details about the methodology, see the Cambium Documentation: Version 2020 ( https://www.nlr.gov/docs/fy21osti/78239.pdf ). This data is planned to be updated annually. Information on the latest versions can be found at https://www.nlr.gov/analysis/cambium.html .

24 POWER TRANSMISSION AND DISTRIBUTION↗

DOE OSTI2022

Long-run Marginal Emission Rates for Electricity - Workbooks for 2021 Cambium Data

These workbooks contain modeled estimates of long-run marginal emission rates (LRMER) for the contiguous United States. The LRMER is an estimate of the rate of emissions that would be either induced or avoided by a long-term (i.e., more than several years) change in electrical demand. It incorporates both the projected changes to the electric grid, as well as the potential for an incremental change in electrical demand to influence the structural evolution of the grid (i.e., the building and retiring of capital assets, such as generators and transmission lines). It is therefore distinct from the more-commonly-known short-run marginal, which treats grid assets as fixed. The Levelized LRMER worksheet within each workbook is set up to produce a levelized long-run marginal emission rate based on user-provided inputs. These levelized LRMER values are intended for analysts to use when estimating the emissions induced (or avoided) by a long-term change in end-use electricity demand. There are two workbooks that supply the data at two different geographic resolutions: states and GEA regions (20 regions that are similar to, but not exactly the same as, the US EPA's eGRID regions). For more data underlying these emissions factors, see the Cambium 2021 project at https://cambium.nrel.gov/. For more details on the inputs into the scenarios available in the workbooks, see the Standard Scenarios 2021 Report (https://www.nrel.gov/docs/fy22osti/80641.pdf). This data was produced as part of the Cambium project. For more details about the methodology, see the Cambium Documentation: Version 2021 (https://www.nrel.gov/docs/fy22osti/81611.pdf). This data is planned to be updated annually. Information on the latest versions can be found at https://www.nrel.gov/analysis/cambium.html.

24 POWER TRANSMISSION AND DISTRIBUTION↗

DOE OSTI2023

Long-run Marginal Emission Rates for Electricity - Workbooks for 2022 Cambium Data

These workbooks contain modeled estimates of long-run marginal emission rates (LRMER) for the contiguous United States. A LRMER is an estimate of the rate of emissions that would be either induced or avoided by a change in electric demand, taking into account how the change could influence both the operation as well as the structure of the grid (i.e., the building and retiring of capital assets, such as generators and transmission lines). It is therefore distinct from the more-commonly-known short-run marginal, which treat grid assets as fixed. Long-run marginal emissions rates are generally appropriate to use when trying to comprehensively estimate the impact of a long-lived (i.e., more than several years) intervention. There are two workbooks that supply the data at two different geographic resolutions: states and GEA regions (20 regions that are similar to, but not exactly the same as, the US EPA's eGRID regions). For more data underlying these emissions factors, see the Cambium 2022 project at https://scenarioviewer.nrel.gov/. For more details on input assumptions and methodology see the associated report (Cambium 2022 Scenario Descriptions and Documentation, https://www.nrel.gov/docs/fy23osti/84916.pdf). This data is planned to be updated annually. Information on the latest versions can be found at https://www.nrel.gov/analysis/cambium.html.

01 COAL, LIGNITE, AND PEAT↗

NASA NTRS1988

Autonomous satellite command and control: A comparison with other military systems

Existing satellite concepts of operation depend on readily available experts and are extremely manpower intensive. Areas of expertise required include mission planning, mission data interpretation, telemetry monitoring, and anomaly resolution. The concepts of operation have envolved to their current state in part because space systems have tended to be treated more as research and development assets rather than as operational assets. These methods of satellite command and control will be inadequate in the future because of the availability, survivability, and capability of human experts. Because space systems have extremely high reliability and limited access, they offer challenges not found in other military systems. Thus, automation techniques used elsewhere are not necessarily applicable to space systems. A program to make satellites much more autonomous has been developed, using a variety of advanced software techniques. The problem the program is addressing, some possible solutions, the goals of the Rome Air Development Center (RADC) program, the rationale as to why the goals are reasonable, and the current program status are discussed. Also presented are some of the concepts used in the program and how they differ from more traditional approaches.

Kruchten, Robert J.↗

NASA NTRS1988

Design guidelines for remotely maintainable equipment

The quantity and complexity of on-orbit assets will increase significantly over the next decade. Maintaining and servicing these costly assets represent a difficult challenge. Three general methods are proposed to maintain equipment while it is still in orbit: an extravehicular activity (EVA) crew can perform the task in an unpressurized maintenance area outside any space vehicle; an intravehicular activity (IVA) crew can perform the maintenance in a shirt sleeve environment, perhaps at a special maintenance work station in a space vehicle; or a telerobotic manipulator can perform the maintenance in an unpressurized maintenance area at a distance from the crew (who may be EVA, IVA, or on the ground). However, crew EVA may not always be possible; the crew may have other demands on their time that take precedence. In addition, the orbit of the tasks themselves may be impossible for crew entry. Also crew IVA may not always be possible as option for equipment maintenance. For example, the equipment may be too large to fit through the vehicle airlock. Therefore, in some circumstances, the third option, telerobotic manipulation, may be the only feasible option. Telerobotic manipulation has, therefore, an important role for on-orbit maintenance. It is not only used for the reasons outlined above, but also used in some cases as backup to the EVA crew in an orbit that they can reach.

Clarke, Margaret M.↗

NASA NTRS1990

A twenty-first century perspective

The status of the NASA assets which are operated by the Office of Space Operations is briefly reviewed. These assets include the ground network, the space network, and communications and data handling facilities. The current plans for each element are examined, and a projection of each is made to meet the user needs in the 21st century. The following factors are noted: increasingly responsive support will be required by the users; operational support concepts must be cost-effective to serve future missions; and a high degree of system reliability and availability will be required to support manned exploration and increasingly complex missions.

Aller, Robert O.↗

NASA NTRS1990

Enhancing orbital servicing operations: Providing positive and effective management of spare and installed hardware - A case study of the Hubble Space Telescope

The Satellite Resources Management and Tracking System was developed specifically for the Hubble Space Telescope (HST) program, and now, NASA has the ability to immediately access the necessary data for planning successful orbital satellite servicing operations. This system is an online, real-time data base system that contains a plethora of data on each item identified to support the HST throughout its planned 15 year life. Some of the information provided includes the current status, location, quantity, and history of each asset, a separate record for each discrete serial numbered item, procurement lead times on items sensitive to technology obsolescence, and the maintenance and repair history of each asset. Finally, details are provided on organizational, operational and logistics requirements.

Randolph, Joseph L.↗

NASA NTRS1992

Supporting multiple domains in a single reuse repository

Domain analysis typically results in the construction of a domain-specific repository. Such a repository imposes artificial boundaries on the sharing of similar assets between related domains. A lattice-based approach to repository modeling can preserve a reuser's domain specific view of the repository, while avoiding replication of commonly used assets and supporting a more general perspective on domain interrelationships.

Eichmann, David↗

NASA NTRS1992

Requirements and applications for robotic servicing of military space systems

The utility of on-orbit servicing of spacecraft has been demonstrated by NASA several times using shuttle-based astronaut EVA. There has been interest in utilizing on-orbit servicing for military space systems as well. This interest has been driven by the increasing reliance of all branches of the military upon space-based assets, the growing numbers, complexity, and cost of those assets, and a desire to normalize support policies for space-based operations. Many military satellites are placed in orbits which are unduly hostile for astronaut operations and/or cannot be reached by the shuttle. In addition, some of the projected tasks may involve hazardous operations. This has led to a focus on robotic systems, instead of astronauts, for the basis of projected servicing systems. This paper describes studies and activities which will hopefully lead to on-orbit servicing being one of the tools available to military space systems designers and operators. The utility of various forms of servicing has been evaluated for present and projected systems, critical technologies have been identified, and strategies for the development and insertion of this technology into operational systems have been developed. Many of the projected plans have been adversely affected by budgetary restrictions and evolving architectures, but the fundamental benefits and requirements are well understood. A method of introducing servicing capabilities in a manner which has a low impact on the system designer and does not require the prior development of an expensive infrastructure is discussed. This can potentially lead to an evolutionary implementation of the full technology.

Ledford, Otto C., Jr.↗

NASA NTRS1992

Supporting multiple domains in a single reuse repository

Eichmann, David A.↗

NASA NTRS1994

Time maintenance system for the BMDO MSX spacecraft

The Johns Hopkins University Applied Physics Laboratory (APL) is responsible for designing and implementing a clock maintenance system for the Ballistic Missile Defense Organizations (BMDO) Midcourse Space Experiment (MSX) spacecraft. The MSX spacecraft has an on-board clock that will be used to control execution of time-dependent commands and to time tag all science and housekeeping data received from the spacecraft. MSX mission objectives have dictated that this spacecraft time, UTC(MSX), maintain a required accuracy with respect to UTC(USNO) of +/- 10 ms with a +/- 1 ms desired accuracy. APL's atomic time standards and the downlinked spacecraft time were used to develop a time maintenance system that will estimate the current MSX clock time offset during an APL pass and make estimates of the clock's drift and aging using the offset estimates from many passes. Using this information, the clock's accuracy will be maintained by uplinking periodic clock correction commands. The resulting time maintenance system is a combination of offset measurement, command/telemetry, and mission planning hardware and computing assets. All assets provide necessary inputs for deciding when corrections to the MSX spacecraft clock must be made to maintain its required accuracy without inhibiting other mission objectives. The MSX time maintenance system is described as a whole and the clock offset measurement subsystem, a unique combination of precision time maintenance and measurement hardware controlled by a Macintosh computer, is detailed. Simulations show that the system estimates the MSX clock offset to less than+/- 33 microseconds.

Hermes, Martin J.↗

NASA NTRS1994

Space transportation activities in the United States

The status of the existing space transportation systems in the U.S. and options for increased capability is being examined in the context of mission requirements, options for new vehicles, cost to operate the existing vehicles, cost to develop new vehicles, and the capabilities and plans of other suppliers. This assessment is addressing the need to build and resupply the space station, to maintain necessary military assets in a rapidly changing world, and to continue a competitive commercial space transportation industry. The Department of Defense (DOD) and NASA each conducted an 'access to space' study using a common mission model but with the emphasis on their unique requirements. Both studies considered three options: maintain and improve the existing capability, build a new launch vehicle using contemporary technology, and build a new launch vehicle using advanced technology. While no decisions have been made on a course of action, it will be influenced by the availability of funds in the U.S. budget, the changing need for military space assets, the increasing competition among space launch suppliers, and the emerging opportunity for an advanced technology, low cost system and international partnerships to develop it.

Gabris, Edward A.↗

NASA NTRS1999

Update of the ISTP Solar Maximum Mission: ISTP Project Scientist for Theory and Ground-Based Observations

Building upon the numerous successes of the pre-solar maximum International Solar Terrestrial Physics (ISTP) mission, the ISTP Solar Maximum Mission is expected to produce new insights into global flow of energy, momentum, and mass, from the Sun, through the heliosphere, into the magnetosphere and to their final deposition in the terrestrial upper atmosphere/ionosphere system. Of particular interest is the determination of the geo-effectiveness of solar events, principally Coronal Mass Ejections (CMEs). Given the expected increased frequency and strength of CMEs during the Solar Maximum period, a major advance in our understanding of nature of the coupling of CMEs to the magnetosphere-ionosphere-atmosphere system is expected. The roles during this time of the various ISTP assets will be discussed. These assets will include the SOHO, Wind, Polar, and Geotail spacecraft, the ground-based observing networks and the theory tools.

Curtis, Steve↗

NASA NTRS1999

Architectural Design for a Mars Communications and Navigation Orbital Infrastructure

The planet Mars has become the focus of an intensive series of missions that span decades of time, a wide array of international agencies and an evolution from robotics to humans. The number of missions to Mars at any one time, and over a period of time, is unprecedented in the annals of space exploration. To meet the operational needs of this exploratory fleet will require the implementation of new architectural concepts for communications and navigation. To this end, NASA's Jet Propulsion Laboratory has begun to define and develop a Mars communications and navigation orbital infrastructure. This architecture will make extensive use of assets at Mars, as well as use of traditional Earth-based assets, such as the Deep Space Network, DSN. Indeed, the total system can be thought of as an extension of DSN nodes and services to the Mars in-situ region. The concept has been likened to the beginnings of an interplanetary Internet that will bring the exploration of Mars right into our living rooms. The paper will begin with a high-level overview of the concept for the Mars communications and navigation infrastructure. Next, the mission requirements will be presented. These will include the relatively near-term needs of robotic landers, rovers, ascent vehicles, balloons, airplanes, and possibly orbiting, arriving and departing spacecraft. Requirements envisioned for the human exploration of Mars will also be described. The important Mars orbit design trades on telecommunications and navigation capabilities will be summarized, and the baseline infrastructure will be described. A roadmap of NASA's plan to evolve this infrastructure over time will be shown. Finally, launch considerations and delivery to Mars will be briefly treated.

Ceasrone R. J.↗

NASA NTRS2000

Mars Communication Protocols

Over the next decade, international plans and commitments are underway to develop an infrastructure at Mars to support future exploration of the red planet. The purpose of this infrastructure is to provide reliable global communication and navigation coverage for on-approach, landed, roving, and in-flight assets at Mars. The claim is that this infrastructure will: 1) eliminate the need of these assets to carry Direct to Earth (DTE) communications equipment, 2) significantly increase data return and connectivity, 3) enable small mission exploration of Mars without DTE equipment, 4) provide precision navigation i.e., 10 to 100m position resolution, 5) supply timing reference accurate to 10ms. This paper in particular focuses on two CCSDS recommendations for that infrastructure: CCSDS Proximity-1 Space Link Protocol and CCSDS File Delivery Protocol (CFDP). A key aspect of Mars exploration will be the ability of future missions to interoperate. These protocols establish a framework for interoperability by providing standard communication, navigation, and timing services. In addition, these services include strategies to recover gracefully from communication interruptions and interference while ensuring backward compatibility with previous missions from previous phases of exploration.

Kazz, G. J.↗

NASA NTRS2001

Next Space Race is in IT

The next Space Race will be in the economic applications from space and science technology. As NASA science and technology has global application; IT is global, economics is global; surely there are great untapped potentials in finding the IT links of commonality among these three. The Economics of IT will continue to depend upon solution providers creating new methods that capitalize on linking information and information centers with the applications community for business and economic functions.. New and innovative IT vendors whose increased efforts to apply evolving technologies and principles that power the e-business revolution are now seeing the business of government being transformed in a similar fashion. NASA will be a prime example of IT transformation. Potential benefits of e-government are identical to the benefits of e-commerce, which start from value derived from capabilities and assets. The capability and asset wealth of NASA technology and data mass scattered through hundreds of archives will one day provide incredible economic benefit across international and corporate boundaries. Yet the ability to economically benefit from bridging the gap between capability to billable service has yet to find it's first major market. Ultimately the role of government, science, and technology linking to the business world will find greater dependence from this increasingly common ground of IT solutions and technologies. Therefore the future role of the IT industry may be as much administrative as technical, ultimately of critical importance furthering the role of science into application.

Alger, George↗

NASA NTRS1995

Building a Successful Security Infrastructure: What You Want vs. What You Need vs. What You Can Afford

With the fast growing popularity of the Internet, many organizations are racing to get onto the on-ramp to the Information Superhighway. However, with frequent headlines such as 'Hackers' break in at General Electric raises questions about the Net's Security', 'Internet Security Imperiled - Hackers steal data that could threaten computers world-wide' and 'Stanford Computer system infiltrated; Security fears grow', organizations find themselves rethinking their approach to the on-ramp. Is the Internet safe? What do I need to do to protect my organization? Will hackers try to break into my systems? These are questions many organizations are asking themselves today. In order to safely travel along the Information Superhighway, organizations need a strong security framework. Developing such a framework for a computer site, whether it be just a few dozen hosts or several thousand hosts is not an easy task. The security infrastructure for a site is often developed piece-by-piece in response to security incidents which have affected that site over time. Or worse yet, no coordinated effort has been dedicated toward security. The end result is that many sites are still poorly prepared to handle the security dangers of the Internet. This paper presents guidelines for building a successful security infrastructure. The problem is addressed in a cookbook style method. First is a discussion on how to identify your assets and evaluate the threats to those assets; next are suggestions and tips for identifying the weak areas in your security armor. Armed with this information we can begin to think about what you really need for your site and what you can afford. In this stage of the process we examine the different categories of security tools and products that are available and then present some tips for deciding what is best for your site.

Crabb, Michele D.↗