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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 379 records · Page 21
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Fitness for Service Assessment of a Corroded Heat Exchanger

Fermilab s Main Injector Accelerator has used shell & tube heat exchangers to cool various beamline components since its construction in the late 1990s. Many of the heat exchangers still around today are original to the machine. Untreated pond water has been used to exchange heat with the Low Conductivity Water. Throughout the lifetime of Fermilab s heat exchangers, they have undergone significant material degradation in the carbon steel end channels due to corrosion. Wall thickness measurements (per API 510) of each heat exchanger were used to generate a 3D model of the corroded surfaces. In order to continue their safe and reliable operation, ASME FFS-1/API 579 (Fitness-For-Service) was implemented to address their integrity. The assessments consisted of finite element analysis techniques outlined in ASME Section VIII Div. 2 (design by analysis methods for pressure vessels), in accordance with the requirements of ASME FFS-1 Part 4: General Metal Loss, Part 5: Local Metal Loss, and Part 9: Crack Like Flaws. The assessments concluded that each heat exchanger is coined Fit For Service . The Fitness-For-Service standard offers a unique opportunity to facilities and institutions within the DOE National Lab complex to properly and safely assess the integrity of aging equipment necessary to conduct science and research. This poster demonstrates the assessment process and techniques used to determine the heat exchangers are fit for service.

Humenik, Alex [Fermilab]↗
DOE OSTI2026

Potential of Data Center Controls in Grid Services

The rapid proliferation of large data centers brings both challenges and opportunities for grid reliability. The data center resources and their potential flexibility have the potential to contribute resources to grid operations. Through capabilities like energy shifting and resource coordination, data centers can help reduce their net demand on the transmission network, as well as provide additional grid services to support reliable operation on the grid. While transient and long-term grid planning and operations are the scenarios that draw most attention, the quasi-steady state timeseries (QSTS) operation of data centers and grid bring interesting scenarios that can help evaluate the data center controls to aid grid services. This work is focused on modeling data centers for QSTS applications – incorporating the AI data center load profiles and building on the PNNL digital twin model for the thermal management loads to enable simulation studies to reveal the impact of data center controls on grid performance. This includes the integration of a QSTS battery and natural gas generator model to incorporate local resource impacts to the system. The simulation study is performed with a modified IEEE 24-Bus transmission system. Scenarios are focused on evaluating the data center load impacts on the transmission system and leveraging both data center and local generation controls to mitigate those impacts and provide additional grid services. The data center controls revealed the ability to contribute to two main kinds of grid services: preventing congestion on a weak grid by coordinating the data center resources with the collocated BESS and onsite generation; and the ability to help the grid operations during stressed times of operation like during a contingency. Leveraging these and other capabilities has the potential to help data centers become grid responsive assets, aiding in both their integration into the power system and grid reliability.

power grid simulation↗
DOE OSTI2024

Deploying Mobility-On-Demand for All by Optimizing Paratransit Services

While on-demand ride-sharing services have become popular in recent years, traditional on-demand transit services cannot be used by everyone, e.g., people who use wheelchairs. Paratransit services, operated by public transit agencies, are a critical infrastructure that offers door-to-door transportation assistance for individuals who face challenges in using standard transit routes. However, with declining ridership and mounting financial pressure, public transit agencies in the USA struggle to operate existing services. We collaborate with a public transit agency from the southern USA, highlight the specific nuances of paratransit optimization, and present a vehicle routing problem formulation for optimizing paratransit. We validate our approach using real-world data from the transit agency, present results from an actual pilot deployment of the proposed approach in the city, and show how the proposed approach comprehensively outperforms existing approaches used by the transit agency. To the best of our knowledge, this work presents one of the first examples of using open-source algorithmic approaches for paratransit optimization.

Pavia, Sophie↗
NASA NTRS1972

Tracking and data relay satellite system configuration and tradeoff study. Volume 4: TDRS system operation and control and telecommunications service system, part 1

Major study areas treated in this volume are: 1) operations and control and 2) the telecommunication service system. The TDRS orbit selection, orbital deployment, ground station visibility, sequence of events from launch to final orbit position, and TDRS control center functions required for stationkeeping, repositioning, attitude control, and antenna pointing are briefly treated as part of the operations and control section. The last topic of this section concerns the operations required for efficiently providing the TDRSS user telecommunication services. The discussion treats functions of the GSFC control and data processing facility, ground station, and TDRS control center. The second major portion of this volume deals with the Telecommunication Service System (TSS) which consists of the ground station, TDRS communication equipment and the user transceiver. A summary of the requirements and objectives for the telecommunication services and a brief summary of the TSS capabilities is followed by communication system analysis, signal design, and equipment design. Finally, descriptions of the three TSS elements are presented.

Source record↗
NASA NTRS1975

Effect of service usage on tensile, fatigue, and fracture properties of 7075-T6 and 7178-T6 aluminum alloys

A study has been made to determine the effects of extensive service usage on some basic material properties of 7075-T6 and 7178-T6 aluminum alloy materials. The effects of service usage were determined by comparing material properties for new material (generally obtained from the literature) with those for material cut from the center wing box of a C-130B transport airplane with 6385 flight-hours of service. The properties investigated were notched and unnotched fatigue strengths, fatigue-crack-growth rate, fracture toughness, and tensile properties. For the properties investigated and the parameter ranges considered (crack length, stress ratio, etc.), the results obtained showed no significant difference between service and new materials.

Everett, R. A., Jr.↗
NASA NTRS1975

Integrated orbital servicing study for low-cost payload programs. Volume 1: Executive summary

Various operating methodologies to achieve low-cost space operations were investigated as part of the Space Transportation System (STS) planning. The emphasis was to show that the development investment, initial fleet costs, and supporting facilities for the STS could be effectively offset by exploiting the capabilities of the STS to satisfy mission requirements and reduce the cost of payload programs. The following major conclusions were reached: (1) the development of an on-orbit servicer maintenance system is compatible with many spacecraft programs and is recommended as the most cost-effective system, (2) spacecraft can be designed to be serviceable with acceptable design, weight, volume, and cost effects, (3) use of on-orbit servicing over a 12 year period results in savings ranging between four and nine billion dollars, (4) the pivoting arm on-orbit servicer was selected and a preliminary design was prepared, (5) orbital maintenance has no significant impact on the STS.

Derocher, W. L., Jr.↗
NASA NTRS1975

Tracking and Data Relay Satellite System /TDRSS/ telecommunication services

The TDRSS and tracking services define the telecommunication performance of the TDRSS between the RF interface with user spacecraft and the data interface with NASCOM at the ground terminal. Attention is given to system constraints, forward link services, multiple-access signal design parameters, S-band single access signal design parameters, multiple-access return link services, and single-access return link services.

Deerkoski, L. F.↗
NASA NTRS1975

A user assessment of servicing at geostationary orbit

Orbital servicing assessed from the viewpoint of a commercial user of communications satellites at geostationary orbit. The need for servicing is emphasized by looking at the history of failures and defects occurring in communications satellites. The methods used in servicing were evaluated in terms of the needs of a communications satellite user. A system that utilizes servicing was studied, and some benefits in addition to cost savings were identified. Most of the assumptions and conclusions apply to earth observation satellites at geostationary orbit.

Gordon, G. D.↗
NASA NTRS1978

Effects of service environments on aluminum-brazed titanium (ABTi)

Aluminum brazed titanium (ABTi) structures were evaluated during prolonged exposure to extreme environments: elevated temperature exposure to airline service fluids, hydraulic fluid, and seawater, followed by laboratory corrosion tests. Solid-face and perforated face honeycomb sandwich panel specimens, stressed panel assemblies, and faying surface brazed joints were tested. The corrosion resistance of ABTi is satisfactory for commercial airline service. Unprotected ABTi proved inherently resistant to attack by all of the extreme service aircraft environments except: seawater at 700 K (800 F) and above, dripping phosphate ester hydraulic fluid at 505 K (450 F), and a marine environment at ambient temperature. The natural oxides and deposits present on titanium surfaces in airline service provide protection against hot salt corrosion pitting. Coatings are required to protect titanium dripping phosphate ester fluid at elevated temperatures and to protect exposed acoustic honeycomb parts against corrosion in a marine environment.

Cotton, W. L.↗
NASA NTRS1977

An overview of aviation weather services

Safety of flight is the first concern of the aviation weather service, the economics of air transportation is a second major interest. Weather is a significant causal factor impacting on the efficiency of air transportation. A discussion is presented on the functions of various weather service agencies as they relate to one another in the dissemination of information to the pilot and to the air traffic controller. Improvements in the aviation weather service and weather knowledge are cited as future goals. The weather service at the present time is an efficient system but future aviation objectives dictate more improvements are needed (especially in automation technology) to enhance flight planning and for safe and efficient flight execution.

Connolly, J. W.↗
NASA NTRS1978

Requirements for regional short-haul air service and the definition of a flight program to determine neighborhood reactions to small transport aircraft

An evaluation of the current status and future requirements of an intraregional short haul air service is given. A brief definition of the different types of short haul air service is given. This is followed by a historical review of previous attempts to develop short haul air service in high density urban areas and an assessment of the current status. The requirements for intraregional air service, the need for economic and environmental viability and the need for a flight research program are defined. A detailed outline of a research program that would determine urban community reaction to frequent operations of small transport aircraft is also given. Both the operation of such an experiment in a specific region (San Francisco Bay area) and the necessary design modifications of an existing fixed wing aircraft which could be used in the experiment are established. An estimate is made of overall program costs.

Feher, K.↗
NASA NTRS1980

Upgrading the free flying rendezvous and docking simulator and the orbital servicer system

Recommendations are made for upgrading two teleoperator/robotics test and simulation systems based upon a review of latest technology advances in the involved disciplines. A second generation Free Flying Mobility Unit is recommended which adds a sixth degree of freedom and incorporates other improvements which greatly expand the center's capability to perform evaluation tests and demonstrations of advanced systems concepts for rendezvous and docking in support of the Teleoperator Maneuvering System (TMS) Program. The Orbital Servicer System provides the capability for testing and demonstrating concepts for on orbit servicing of compatibly designed satellites/payloads. The TMS is to be the transporting vehicle for the servicer. The manipulator arm of the Orbital service System is presently computer controlled in the trajectory portion of the module transfer operation. The ultimate objective is to fully automte its operation requiring additional capabilities in sensors, artificial intelligence, image analysis, communications, computer programming, pattern recognition, kinematics, and manipulator design. It is recommended that the Electronics and Control Laboratory move to acquire the basic competencies in robotics necessary to achieve full automation.

Eastman, R. M.↗
NASA NTRS1981

Satellite services system analysis study. Volume 2, part 2: Study results

The development of an effective satellite services system was investigated. Satek Satellite user market, design reference missions, satellite service functions, service equipment, and cost estimates are discussed. Extensive program plans for a satellite service system implementation are included.

Source record↗
NASA NTRS1981

Generalized variables for controlling Government Transfer Services with respect to performance measures

The term Government Transfer Services is used in reference to any of the organized streams of public resources that flow into private economic activity. This includes such activities as offshore leasing, Social Security, and NASA technology transfer services. This paper describes a performance measure, empirical results, a theory, and a control model for such services. These are illustrated by a specific example (NASA). An agenda for developing this service control method is also presented.

Johnson, F. D.↗
NASA NTRS1982

The role of SRMS in satellite servicing

The standard configuration of the shuttle remote manipulator system (RMS) is reviewed and the role of the RMS in satellite servicing is discussed. The RMS tasks include payload deployment, retrieval/berthing, large spacecraft assembly/module exchange, assist astronaut extravehicular servicing, and remote servicing. The potential growth of the RMS to increase its utilization and improve its performance is also addressed. The projected concepts include dual arm operation, a remote mounted RMS, and special purpose end effectors. In particular, a universal service tool system with both remote and manual modes of operation is described.

Fuller, R. B.↗
NASA NTRS1983

Customer premise service study for 30/20 GHz satellite system

Satellite systems in which the space segment operates in the 30/20 GHz frequency band are defined and compared as to their potential for providing various types of communications services to customer premises and the economic and technical feasibility of doing so. Technical tasks performed include: market postulation, definition of the ground segment, definition of the space segment, definition of the integrated satellite system, service costs for satellite systems, sensitivity analysis, and critical technology. Based on an analysis of market data, a sufficiently large market for services is projected so as to make the system economically viable. A large market, and hence a high capacity satellite system, is found to be necessary to minimize service costs, i.e., economy of scale is found to hold. The wide bandwidth expected to be available in the 30/20 GHz band, along with frequency reuse which further increases the effective system bandwidth, makes possible the high capacity system. Extensive ground networking is required in most systems to both connect users into the system and to interconnect Earth stations to provide spatial diversity. Earth station spatial diversity is found to be a cost effective means of compensating the large fading encountered in the 30/20 GHz operating band.

Milton, R. T.↗