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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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1987

Servicer system demonstration plan and capability development

An orbital maneuvering vehicle (OMV) front end kit is defined which is capable of performing in-situ fluid resupply and modular maintenance of free flying spacecraft based on the integrated orbital servicing system (IOSS) concept. The compatibility of the IOSS to perform gas and fluid umbilical connect and disconnect functions utilizing connect systems currently available or in development is addressed. A series of tasks involving on-orbit servicing and the engineering test unit (ETU) of the on-orbit service were studied. The objective is the advancement of orbital servicing by expanding the Spacecraft Servicing Demonstration Plan (SSDP) to include detail demonstration planning using the Multimission Modular Spacecraft (MMS) and upgrading the ETU control.

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NASA NTRS1983

Time-critical multirate scheduling using contemporary real-time operating system services

Although real-time operating systems provide many of the task control services necessary to process time-critical applications (i.e., applications with fixed, invariant deadlines), it may still be necessary to provide a scheduling algorithm at a level above the operating system in order to coordinate a set of synchronized, time-critical tasks executing at different cyclic rates. The scheduling requirements for such applications and develops scheduling algorithms using services provided by contemporary real-time operating systems.

Eckhardt, D. E., Jr.↗
NASA NTRS1990

Canada's Mobile Servicing System

An overview of Canada's part in the Space Station Freedom program, as a provider and operator of station flight elements and as a user, is given. The Mobile Servicing System (MSS) which will provide the Station with its manipulative capability, systems functions, station assembly, and maintenance of station elements, is described. Organizational activities and schedule requirements are examined, and the performance characteristics of the system are presented.

Erb, R. Bryan↗
NASA NTRS1975

Apollo experience report: Guidance and control systems: CSM service propulsion system gimbal actuators

The service propulsion system gimbal actuators of the Apollo command and service module were developed, modified, and qualified between February 1962 and April 1968. The development of these actuators is described as the result of extensive testing, retesting, and modification of the initial design. Successful completion of each mission without anomalies attributable to the actuators indicated that the particular configuration (modification) in use was adequate for the flight profile imposed.

Mcmahon, W. A.↗
DOE OSTI2021

Preliminary Environmental and Financial Viability Analysis of Circular Economy Scenarios for Satisfying PV System Service Lifetime

PV deployment has grown rapidly in recent decades, and this growth is expected to continue. At the same time, the rapid increase in PV panel efficiencies offers the opportunity to repower/revamp existing installations - replacing operational, lower-efficiency panels before the end of their 30-year service lifetime with newer, higher-efficiency panels. As a result, an increasing volume of PV panels could be decommissioned well before reaching the end of their 30-year service lifetime. Two broad strategies can be applied to manage the expected increase in decommissioned PV panels: (i) recycle prematurely decommissioned panels, and (ii) prevent recycling of these panels by satisfying the typical service lifetime of 30 years through circular economy strategies such as repair and reuse. Each strategy presents an environmental and economic trade-off. Retaining and satisfying the lifetime of the older, lower-efficiency panels avoids environmental burdens from recycling or landfilling but incurs burdens from additional repair and forgoing the opportunity to install newer panels with greater electricity-generation capabilities. This study assesses whether satisfying the expected service lifetime of a PV system through circular economy scenarios generates a greater environmental and financial benefit than recycling used panels and installing newer panels with higher efficiencies. The circular economy scenarios include repair and reuse of the PV system. Specifically, the study determines whether it is better for the environment to keep a PV panel in use for its 30-year service life after accounting for potential repair and additional transportation, or to replace older panels with more efficient new ones. In addition, we explore whether satisfying the service lifetime of PV panels proves competitive with the recycling route from a financial perspective.

14 SOLAR ENERGY↗
NASA NTRS1980

Solar heating, cooling and domestic hot water system installed at Columbia Gas System Service Corporation, Columbus, Ohio

The solar energy system installed in the building has 2,978 sq ft of single axis tracking, concentrating collectors and provides solar energy for space heating, space cooling and domestic hot water. A 1,200,000 Btu/hour water tube gas boiler provides hot water for space heating. Space cooling is provided by a 100 ton hot water fired absorption chiller. Domestic hot water heating is provided by a 50 gallon natural gas domestic storage water heater. Extracts from the site files, specification references, drawings, installation, operation and maintenance instructions are included.

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NASA NTRS1981

Satellite services system analysis study. Volume 1: Executive summary

Service requirements are considered. Topics include development of on-orbit operations scenarios, service equipment summary, crew interaction, and satellite features facilitating servicing. Service equipment concepts are considered. Topics include payload deployment, close proximity retrieval, on-orbit servicing, backup/contingency, delivery/retrieval of high energy payloads, Earth return, optional service, and advanced capabilities. Program requirements are assessed.

Source record↗
NASA NTRS1985

Advanced Information Processing System (AIPS) proof-of-concept system functional design I/O network system services

The function design of the Input/Output (I/O) services for the Advanced Information Processing System (AIPS) proof of concept system is described. The data flow diagrams, which show the functional processes in I/O services and the data that flows among them, are contained. A complete list of the data identified on the data flow diagrams and in the process descriptions are provided.

Source record↗
NASA NTRS2007

The NASA Dryden Flight Research Center Unmanned Aircraft System Service Capabilities

Over 60 years of Unmanned Aircraft System (UAS) expertise at the NASA Dryden Flight Research Center are being leveraged to provide capability and expertise to the international UAS community. The DFRC brings together technical experts, UAS, and an operational environment to provide government and industry a broad capability to conduct research, perform operations, and mature systems, sensors, and regulation. The cornerstone of this effort is the acquisition of both a Global Hawk (Northrop Grumman Corporation, Los Angeles, California) and Predator B (General Atomics Aeronautical Systems, Inc., San Diego, California) unmanned aircraft system (UAS). In addition, a test range for small UAS will allow developers to conduct research and development flights without the need to obtain approval from civil authorities. Finally, experts are available to government and industry to provide safety assessments in support of operations in civil airspace. These services will allow developers to utilize limited resources to their maximum capability in a highly competitive environment.

Bauer, Jeff↗
NASA NTRS2007

The NASA Dryden Flight Research Center Unmanned Aircraft System Service Capabilities

Over 60 years of Unmanned Aircraft System (UAS) expertise at the National Aeronautics and Space Administration (NASA) Dryden Flight Research Center are being leveraged to provide capability and expertise to the international UAS community. The DFRC brings together technical experts, UAS, and an operational environment to provide government and industry a broad capability to conduct research, perform operations, and mature systems, sensors, and regulation. The cornerstone of this effort is the acquisition of both a Global Hawk (Northrop Grumman Corporation, Los Angeles, California) and Predator B (General Atomics Aeronautical Systems, Inc., San Diego, California) unmanned aircraft system (UAS). In addition, a test range for small UAS will allow developers to conduct research and development flights without the need to obtain approval from civil authorities. Finally, experts are available to government and industry to provide safety assessments in support of operations in civil airspace. These services will allow developers to utilize limited resources to their maximum capability in a highly competitive environment.

Bauer, Jeff↗
NASA NTRS1979

The 18/30 GHz fixed communications system service demand assessment. Volume 2: Main text

The total demand for communications services, and satellite transmission services at the 4/6 GHz, 12/14 GHz, and 18/30 GHz frequencies is assessed. The services are voice, video, and data services. Traffic demand, by service, is distributed by geographical regions, population density, and distance between serving points. Further distribution of traffic is made among four major end user groups: business, government, institutions and private individuals. A traffic demand analysis is performed on a typical metropolitan city to examine service distribution trends. The projected cost of C and Ku band satellite systems are compared on an individual service basis to projected terrestrial rates. Separation of traffic between transmission systems, including 18/30 GHz systems, is based on cost, user, and technical considerations.

Gabriszeski, T.↗
NASA NTRS1985

Satellite services system program plan

The purpose is to determine the potential for servicing from the Space Shuttle Orbiter and to assess NASA's role as the catalyst in bringing about routine on-orbit servicing. Specifically this study seeks to determine what requirements, in terms of both funds and time, are needed to make the Shuttle Orbiter not only a transporter of spacecraft but a servicing vehicle for those spacecraft as well. The scope of this effort is to focus on the near term development of a generic servicing capability. To make this capability truly generic and attractive requires that the customer's point of veiw be taken and transformed into a widely usable set of hardware. And to maintain a near term advent of this capability requires that a minimal reliance be made on advanced technology. With this background and scope, this study will proceed through three general phases to arrive at the desired program costs and schedule. The first step will be to determine the servicing requirements of the user community. This will provide the basis for the second phase which is to develop hardware concepts to meet these needs. Finally, a cost estimate will be made for each of the new hardware concepts and a phased hardware development plan will be established for the acquisition of these items based on the inputs obtained from the user community.

Hoffman, Stephen J.↗
DOE OSTI2022

Online Learning and Pricing for Service Systems with Reusable Resources

We consider a price-based revenue management problem with finite reusable resources over a finite time horizon T. Customers arrive following a price-dependent Poisson process, and each customer requests one unit of c homogeneous reusable resources. If there is an available unit, the customer gets served within a price-dependent exponentially distributed service time; otherwise, the customer waits in a queue until the next available unit. In this paper, we assume that the firm does not know how the arrival and service rates depend on posted prices, and thus it makes adaptive pricing decisions in each period based only on past observations to maximize the cumulative revenue. Given a discrete price set with cardinality P, we propose two online learning algorithms, termed batch upper confidence bound (BUCB) and batch Thompson sampling (BTS), and prove that the cumulative regret upper bound is O˜(√PT) , which matches the regret lower bound. In establishing the regret, we bound the transient system performance upon price changes via a novel coupling argument, and also generalize bandits to accommodate subexponential rewards. Here, we also extend our approach to models with balking and reneging customers and discuss a continuous price setting. Our numerical experiments demonstrate the efficacy of the proposed BUCB and BTS algorithms.

97 MATHEMATICS AND COMPUTING↗
NASA NTRS1985

Servicers system demonstration plan and capability development

A plan for the demonstration of the exchange of Multi-Mission Modular Spacecraft (MMS) modules using the servicer mechanism Engineering Test Unit (ETU) was prepared and executed. The plan included: establishment of requirements, conceptual design, selection of MMS spacecraft mockup configuration, selection of MMS module mockup configuration, evaluation of adequacy of ETU load capability, and selection of a stowage rack arrangement. The MMS module exchange demonstration mockup equipment was designed, fabricated, checked out, shipped, installed, and demonstrated.

Bulboaca, M. A.↗
NASA NTRS1979

The 30/20 GHz fixed communications systems service demand assessment. Volume 3: Annex

A review of studies forecasting the communication market in the United States is given. The applicability of these forecasts to assessment of demand for the 30/20 GHz fixed communications system is analyzed. Costs for the 30/20 satellite trunking systems are presented and compared with the cost of terrestrial communications.

Gamble, R. B.↗