Reliability and cost: A sensitivity analysis
NASA Technical Reports Server (NTRS)
Suich, Ronald C.; Patterson, Richard L.
1991-01-01
In the design phase of a system, how a design engineer or manager choose between a subsystem with .990 reliability and a more costly subsystem with .995 reliability is examined, along with the justification of the increased cost. High reliability is not necessarily an end in itself but may be desirable in order to reduce the expected cost due to subsystem failure. However, this may not be the wisest use of funds since the expected cost due to subsystem failure is not the only cost involved. The subsystem itself may be very costly. The cost of the subsystem nor the expected cost due to subsystem failure should not be considered separately but the total of the two costs should be maximized, i.e., the total of the cost of the subsystem plus the expected cost due to subsystem failure.
Sensitivity of Space Shuttle Weight and Cost to Structure Subsystem Weights
NASA Technical Reports Server (NTRS)
Wedge, T. E.; Williamson, R. P.
1973-01-01
Quantitative relationships between changes in space shuttle weights and costs with changes in weight of various portions of space shuttle structural subsystems are investigated. These sensitivity relationships, as they apply at each of three points in the development program (preliminary design phase, detail design phase, and test/operational phase) have been established for five typical space shuttle designs, each of which was responsive to the missions in the NASA Shuttle RFP, and one design was that selected by NASA.
Systems Analysis Of Advanced Coal-Based Power Plants
NASA Technical Reports Server (NTRS)
Ferrall, Joseph F.; Jennings, Charles N.; Pappano, Alfred W.
1988-01-01
Report presents appraisal of integrated coal-gasification/fuel-cell power plants. Based on study comparing fuel-cell technologies with each other and with coal-based alternatives and recommends most promising ones for research and development. Evaluates capital cost, cost of electricity, fuel consumption, and conformance with environmental standards. Analyzes sensitivity of cost of electricity to changes in fuel cost, to economic assumptions, and to level of technology. Recommends further evaluation of integrated coal-gasification/fuel-cell integrated coal-gasification/combined-cycle, and pulverized-coal-fired plants. Concludes with appendixes detailing plant-performance models, subsystem-performance parameters, performance goals, cost bases, plant-cost data sheets, and plant sensitivity to fuel-cell performance.
Reliability and cost analysis methods
NASA Technical Reports Server (NTRS)
Suich, Ronald C.
1991-01-01
In the design phase of a system, how does a design engineer or manager choose between a subsystem with .990 reliability and a more costly subsystem with .995 reliability? When is the increased cost justified? High reliability is not necessarily an end in itself but may be desirable in order to reduce the expected cost due to subsystem failure. However, this may not be the wisest use of funds since the expected cost due to subsystem failure is not the only cost involved. The subsystem itself may be very costly. We should not consider either the cost of the subsystem or the expected cost due to subsystem failure separately but should minimize the total of the two costs, i.e., the total of the cost of the subsystem plus the expected cost due to subsystem failure. This final report discusses the Combined Analysis of Reliability, Redundancy, and Cost (CARRAC) methods which were developed under Grant Number NAG 3-1100 from the NASA Lewis Research Center. CARRAC methods and a CARRAC computer program employ five models which can be used to cover a wide range of problems. The models contain an option which can include repair of failed modules.
Balancing reliability and cost to choose the best power subsystem
NASA Technical Reports Server (NTRS)
Suich, Ronald C.; Patterson, Richard L.
1991-01-01
A mathematical model is presented for computing total (spacecraft) subsystem cost including both the basic subsystem cost and the expected cost due to the failure of the subsystem. This model is then used to determine power subsystem cost as a function of reliability and redundancy. Minimum cost and maximum reliability and/or redundancy are not generally equivalent. Two example cases are presented. One is a small satellite, and the other is an interplanetary spacecraft.
Sensitivities of projected 1980 photovoltaic system costs to major system cost drivers
NASA Technical Reports Server (NTRS)
Zimmerman, L. W.; Smith, J. L.
1984-01-01
The sensitivity of projected 1990 photovoltaic (PV) system costs to major system cost drivers was examined. It includes: (1) module costs and module efficiencies; (2) area related balance of system (BOS) costs; (3) inverter costs and efficiencies; and (4) module marketing and distribution markups and system integration fees. Recent PV system cost experiences and the high costs of electricity from the systems are reviewed. The 1990 system costs are projected for five classes of PV systems, including four ground mounted 5-MWp systems and one residential 5-kWp system. System cost projections are derived by first projecting costs and efficiencies for all subsystems and components. Sensitivity analyses reveal that reductions in module cost and engineering and system integration fees seem to have the greatest potential for contributing to system cost reduction. Although module cost is clearly the prime candidate for fruitful PV research and development activities, engineering and system integration fees seem to be more amenable to reduction through appropriate choice of system size and market strategy. Increases in inverter and module efficiency yield significant benefits, especially for systems with high area related costs.
[Financing, organization, costs and services performance of the Argentinean health sub-systems.
Yavich, Natalia; Báscolo, Ernesto Pablo; Haggerty, Jeannie
2016-01-01
To analyze the relationship between health system financing and services organization models with costs and health services performance in each of Rosario's health sub-systems. The financing and organization models were characterized using secondary data. Costs were calculated using the WHO/SHA methodology. Healthcare quality was measured by a household survey (n=822). Public subsystem:Vertically integrated funding and primary healthcare as a leading strategy to provide services produced low costs and individual-oriented healthcare but with weak accessibility conditions and comprehensiveness. Private subsystem: Contractual integration and weak regulatory and coordination mechanisms produced effects opposed to those of the public sub-system. Social security: Contractual integration and strong regulatory and coordination mechanisms contributed to intermediate costs and overall high performance. Each subsystem financing and services organization model had a strong and heterogeneous influence on costs and health services performance.
Cost analysis of life sciences experiments and subsystems. [to be carried in the Spacelab
NASA Technical Reports Server (NTRS)
Yakut, M. M.
1975-01-01
Cost estimates for experiments and subsystems flown in the Spacelab were established. Ten experiments were cost analyzed. Estimated cost varied from $650,000 for the hardware development of the SPE water electrolysis experiment to $78,500,000 for the development and operation of a representative life sciences laboratory program. The cost of subsystems for thermal, atmospheric and trace contaminants control of the Spacelab internal atmosphere was also estimated. Subsystem cost estimates were based on the utilization of existing components developed in previous space programs whenever necessary.
Spacecraft expected cost analysis with k-out-of-n:G subsystems
NASA Technical Reports Server (NTRS)
Patterson, Richard; Suich, Ron
1991-01-01
In designing a subsystem for a spacecraft, the design engineer is often faced with a number of options ranging from planning an inexpensive subsystem with low reliability to selecting a highly reliable system that would cost much more. We minimize the total of the cost of the subsytem and the costs that would occur if the subsystem fails. We choose the subsystem with the lowest total. A k-out-of-n:G subsystem has n modules, of which k are required to be good for the subsystem to be good. We examine two models to illustrate the principles of the k-out-of-n:G subsystem designs. For the first model, the following assumptions are necessary: the probability of failure of any module in the system is not affected by the failure of any other module; and each of the modules has the same probabillity of success. For the second model we are also free to choose k in our subsystem.
The multi-disciplinary design study: A life cycle cost algorithm
NASA Technical Reports Server (NTRS)
Harding, R. R.; Pichi, F. J.
1988-01-01
The approach and results of a Life Cycle Cost (LCC) analysis of the Space Station Solar Dynamic Power Subsystem (SDPS) including gimbal pointing and power output performance are documented. The Multi-Discipline Design Tool (MDDT) computer program developed during the 1986 study has been modified to include the design, performance, and cost algorithms for the SDPS as described. As with the Space Station structural and control subsystems, the LCC of the SDPS can be computed within the MDDT program as a function of the engineering design variables. Two simple examples of MDDT's capability to evaluate cost sensitivity and design based on LCC are included. MDDT was designed to accept NASA's IMAT computer program data as input so that IMAT's detailed structural and controls design capability can be assessed with expected system LCC as computed by MDDT. No changes to IMAT were required. Detailed knowledge of IMAT is not required to perform the LCC analyses as the interface with IMAT is noninteractive.
Maintenance and operations cost model for DSN subsystems
NASA Technical Reports Server (NTRS)
Burt, R. W.; Lesh, J. R.
1977-01-01
A procedure is described which partitions the recurring costs of the Deep Space Network (DSN) over the individual DSN subsystems. The procedure results in a table showing the maintenance, operations, sustaining engineering and supportive costs for each subsystems.
Minimize system cost by choosing optimal subsystem reliability and redundancy
NASA Technical Reports Server (NTRS)
Suich, Ronald C.; Patterson, Richard L.
1993-01-01
The basic question which we address in this paper is how to choose among competing subsystems. This paper utilizes both reliabilities and costs to find the subsystems with the lowest overall expected cost. The paper begins by reviewing some of the concepts of expected value. We then address the problem of choosing among several competing subsystems. These concepts are then applied to k-out-of-n: G subsystems. We illustrate the use of the authors' basic program in viewing a range of possible solutions for several different examples. We then discuss the implications of various solutions in these examples.
NASA Technical Reports Server (NTRS)
Janz, R. F.
1974-01-01
The systems cost/performance model was implemented as a digital computer program to perform initial program planning, cost/performance tradeoffs, and sensitivity analyses. The computer is described along with the operating environment in which the program was written and checked, the program specifications such as discussions of logic and computational flow, the different subsystem models involved in the design of the spacecraft, and routines involved in the nondesign area such as costing and scheduling of the design. Preliminary results for the DSCS-II design are also included.
Optimizing preventive maintenance policy: A data-driven application for a light rail braking system.
Corman, Francesco; Kraijema, Sander; Godjevac, Milinko; Lodewijks, Gabriel
2017-10-01
This article presents a case study determining the optimal preventive maintenance policy for a light rail rolling stock system in terms of reliability, availability, and maintenance costs. The maintenance policy defines one of the three predefined preventive maintenance actions at fixed time-based intervals for each of the subsystems of the braking system. Based on work, maintenance, and failure data, we model the reliability degradation of the system and its subsystems under the current maintenance policy by a Weibull distribution. We then analytically determine the relation between reliability, availability, and maintenance costs. We validate the model against recorded reliability and availability and get further insights by a dedicated sensitivity analysis. The model is then used in a sequential optimization framework determining preventive maintenance intervals to improve on the key performance indicators. We show the potential of data-driven modelling to determine optimal maintenance policy: same system availability and reliability can be achieved with 30% maintenance cost reduction, by prolonging the intervals and re-grouping maintenance actions.
Optimizing preventive maintenance policy: A data-driven application for a light rail braking system
Corman, Francesco; Kraijema, Sander; Godjevac, Milinko; Lodewijks, Gabriel
2017-01-01
This article presents a case study determining the optimal preventive maintenance policy for a light rail rolling stock system in terms of reliability, availability, and maintenance costs. The maintenance policy defines one of the three predefined preventive maintenance actions at fixed time-based intervals for each of the subsystems of the braking system. Based on work, maintenance, and failure data, we model the reliability degradation of the system and its subsystems under the current maintenance policy by a Weibull distribution. We then analytically determine the relation between reliability, availability, and maintenance costs. We validate the model against recorded reliability and availability and get further insights by a dedicated sensitivity analysis. The model is then used in a sequential optimization framework determining preventive maintenance intervals to improve on the key performance indicators. We show the potential of data-driven modelling to determine optimal maintenance policy: same system availability and reliability can be achieved with 30% maintenance cost reduction, by prolonging the intervals and re-grouping maintenance actions. PMID:29278245
Millimeter wave satellite concepts, volume 1
NASA Technical Reports Server (NTRS)
Hilsen, N. B.; Holland, L. D.; Thomas, R. E.; Wallace, R. W.; Gallagher, J. G.
1977-01-01
The identification of technologies necessary for development of millimeter spectrum communication satellites was examined from a system point of view. Development of methodology based on the technical requirements of potential services that might be assigned to millimeter wave bands for identifying the viable and appropriate technologies for future NASA millimeter research and development programs, and testing of this methodology with selected user applications and services were the goals of the program. The entire communications network, both ground and space subsystems was studied. Cost, weight, and performance models for the subsystems, conceptual design for point-to-point and broadcast communications satellites, and analytic relationships between subsystem parameters and an overall link performance are discussed along with baseline conceptual systems, sensitivity studies, model adjustment analyses, identification of critical technologies and their risks, and brief research and development program scenarios for the technologies judged to be moderate or extensive risks. Identification of technologies for millimeter satellite communication systems, and assessment of the relative risks of these technologies, was accomplished through subsystem modeling and link optimization for both point-to-point and broadcast applications.
Optimum dry-cooling sub-systems for a solar air conditioner
NASA Technical Reports Server (NTRS)
Chen, J. L. S.; Namkoong, D.
1978-01-01
Dry-cooling sub-systems for residential solar powered Rankine compression air conditioners were economically optimized and compared with the cost of a wet cooling tower. Results in terms of yearly incremental busbar cost due to the use of dry-cooling were presented for Philadelphia and Miami. With input data corresponding to local weather, energy rate and capital costs, condenser surface designs and performance, the computerized optimization program yields design specifications of the sub-system which has the lowest annual incremental cost.
Space transfer vehicle concepts and requirements study. Volume 3, book 1: Program cost estimates
NASA Technical Reports Server (NTRS)
Peffley, Al F.
1991-01-01
The Space Transfer Vehicle (STV) Concepts and Requirements Study cost estimate and program planning analysis is presented. The cost estimating technique used to support STV system, subsystem, and component cost analysis is a mixture of parametric cost estimating and selective cost analogy approaches. The parametric cost analysis is aimed at developing cost-effective aerobrake, crew module, tank module, and lander designs with the parametric cost estimates data. This is accomplished using cost as a design parameter in an iterative process with conceptual design input information. The parametric estimating approach segregates costs by major program life cycle phase (development, production, integration, and launch support). These phases are further broken out into major hardware subsystems, software functions, and tasks according to the STV preliminary program work breakdown structure (WBS). The WBS is defined to a low enough level of detail by the study team to highlight STV system cost drivers. This level of cost visibility provided the basis for cost sensitivity analysis against various design approaches aimed at achieving a cost-effective design. The cost approach, methodology, and rationale are described. A chronological record of the interim review material relating to cost analysis is included along with a brief summary of the study contract tasks accomplished during that period of review and the key conclusions or observations identified that relate to STV program cost estimates. The STV life cycle costs are estimated on the proprietary parametric cost model (PCM) with inputs organized by a project WBS. Preliminary life cycle schedules are also included.
Comparative evaluation of distributed-collector solar thermal electric power plants
NASA Technical Reports Server (NTRS)
Fujita, T.; El Gabalawi, N.; Herrera, G. G.; Caputo, R. S.
1978-01-01
Distributed-collector solar thermal-electric power plants are compared by projecting power plant economics of selected systems to the 1990-2000 timeframe. The approach taken is to evaluate the performance of the selected systems under the same weather conditions. Capital and operational costs are estimated for each system. Energy costs are calculated for different plant sizes based on the plant performance and the corresponding capital and maintenance costs. Optimum systems are then determined as the systems with the minimum energy costs for a given load factor. The optimum system is comprised of the best combination of subsystems which give the minimum energy cost for every plant size. Sensitivity analysis is done around the optimum point for various plant parameters.
NASA Technical Reports Server (NTRS)
Campbell, B. H.
1974-01-01
A methodology which was developed for balanced designing of spacecraft subsystems and interrelates cost, performance, safety, and schedule considerations was refined. The methodology consists of a two-step process: the first step is one of selecting all hardware designs which satisfy the given performance and safety requirements, the second step is one of estimating the cost and schedule required to design, build, and operate each spacecraft design. Using this methodology to develop a systems cost/performance model allows the user of such a model to establish specific designs and the related costs and schedule. The user is able to determine the sensitivity of design, costs, and schedules to changes in requirements. The resulting systems cost performance model is described and implemented as a digital computer program.
Electrochemical energy storage subsystems study, volume 1
NASA Technical Reports Server (NTRS)
Miller, F. Q.; Richardson, P. W.; Graff, C. L.; Jordan, M. V.; Patterson, V. L.
1981-01-01
The effects on life cycle costs (LCC) of major design and performance technology parameters for multi kW LEO and GEO energy storage subsystems using NiCd and NiH2 batteries and fuel cell/electrolysis cell devices were examined. Design, performance and LCC dynamic models are developed based on mission and system/subsystem requirements and existing or derived physical and cost data relationships. The models define baseline designs and costs. The major design and performance parameters are each varied to determine their influence on LCC around the baseline values.
Electrochemical Energy Storage Subsystems Study, Volume 2
NASA Technical Reports Server (NTRS)
Miller, F. Q.; Richardson, P. W.; Graff, C. L.; Jordan, M. V.; Patterson, V. L.
1981-01-01
The effects on life cycle costs (LCC) of major design and performance technology parameters for multi kW LEO and GEO energy storage subsystems using NiCd and NiH2 batteries and fuel cell/electrolysis cell devices were examined. Design, performance and LCC dynamic models are developed based on mission and system/subsystem requirements and existing or derived physical and cost data relationships. The models are exercised to define baseline designs and costs. Then the major design and performance parameters are each varied to determine their influence on LCC around the baseline values.
Jung, Youngmee Tiffany; Narayanan, N C; Cheng, Yu-Ling
2018-05-01
There is a growing interest in decentralized wastewater management (DWWM) as a potential alternative to centralized wastewater management (CWWM) in developing countries. However, the comparative cost of CWWM and DWWM is not well understood. In this study, the cost of cluster-type DWWM is simulated and compared to the cost of CWWM in Alibag, India. A three-step model is built to simulate a broad range of potential DWWM configurations with varying number and layout of cluster subsystems. The considered DWWM scheme consists of cluster subsystems, that each uses simplified sewer and DEWATS (Decentralized Wastewater Treatment Systems). We consider CWWM that uses conventional sewer and an activated sludge plant. The results show that the cost of DWWM can vary significantly with the number and layout of the comprising cluster subsystems. The cost of DWWM increased nonlinearly with increasing number of comprising clusters, mainly due to the loss in the economies of scale for DEWATS. For configurations with the same number of comprising cluster subsystems, the cost of DWWM varied by ±5% around the mean, depending on the layout of the cluster subsystems. In comparison to CWWM, DWWM was of lower cost than CWWM when configured with fewer than 16 clusters in Alibag, with significantly less operation and maintenance requirement, but with higher capital and land requirement for construction. The study demonstrates that cluster-type DWWM using simplified sewer and DEWATS may be a cost-competitive alternative to CWWM, when carefully configured to lower the cost. Copyright © 2018 Elsevier Ltd. All rights reserved.
NASA Technical Reports Server (NTRS)
Wolf, M.
1979-01-01
To facilitate the task of objectively comparing competing process options, a methodology was needed for the quantitative evaluation of their relative cost effectiveness. Such a methodology was developed and is described, together with three examples for its application. The criterion for the evaluation is the cost of the energy produced by the system. The method permits the evaluation of competing design options for subsystems, based on the differences in cost and efficiency of the subsystems, assuming comparable reliability and service life, or of competing manufacturing process options for such subsystems, which include solar cells or modules. This process option analysis is based on differences in cost, yield, and conversion efficiency contribution of the process steps considered.
Cost analysis of oxygen recovery systems
NASA Technical Reports Server (NTRS)
Yakut, M. M.
1973-01-01
The design and development of equipment for flight use in earth-orbital programs, when optimally approached cost effectively, proceed through the following logical progression: (1) bench testing of breadboard designs, (2) the fabrication and evaluation of prototype equipment, (3) redesign to meet flight-imposed requirements, and (4) qualification and testing of a flight-ready system. Each of these steps is intended to produce the basic design information necessary to progress to the next step. The cost of each step is normally substantially less than that of the following step. An evaluation of the cost elements involved in each of the steps and their impact on total program cost are presented. Cost analyses of four leading oxygen recovery subsystems which include two carbon dioxide reduction subsystem, Sabatier and Bosch, and two water electrolysis subsystems, the solid polymer electrolyte and the circulating KOH electrolyte are described.
Characterization of a low concentrator photovoltaics module
NASA Astrophysics Data System (ADS)
Butler, B. A.; van Dyk, E. E.; Vorster, F. J.; Okullo, W.; Munji, M. K.; Booysen, P.
2012-05-01
Low concentration photovoltaic (LCPV) systems have the potential to reduce the cost per kWh of electricity compared to conventional flat-plate photovoltaics (PV) by up to 50%. The cost-savings are realised by replacing expensive PV cells with relatively cheaper optical components to concentrate incident solar irradiance onto a receiver and by tracking the sun along either 1 axis or 2 axes. A LCPV module consists of three interrelated subsystems, viz., the optical, electrical and the thermal subsystems, which must be considered for optimal module design and performance. Successful integration of these subsystems requires the balancing of cost, performance and reliability. In this study LCPV experimental prototype modules were designed, built and evaluated with respect to optimisation of the three subsystems and overall performance. This paper reports on the optical and electrical evaluation of a prototype LCPV module.
Controlled Ecological Life Support Systems (CELSS) conceptual design option study
NASA Technical Reports Server (NTRS)
Oleson, Melvin; Olson, Richard L.
1986-01-01
Results are given of a study to explore options for the development of a Controlled Ecological Life Support System (CELSS) for a future Space Station. In addition, study results will benefit the design of other facilities such as the Life Sciences Research Facility, a ground-based CELSS demonstrator, and will be useful in planning longer range missions such as a lunar base or manned Mars mission. The objectives were to develop weight and cost estimates for one CELSS module selected from a set of preliminary plant growth unit (PGU) design options. Eleven Space Station CELSS module conceptual PGU designs were reviewed, components and subsystems identified and a sensitivity analysis performed. Areas where insufficient data is available were identified and divided into the categories of biological research, engineering research, and technology development. Topics which receive significant attention are lighting systems for the PGU, the use of automation within the CELSS system, and electric power requirements. Other areas examined include plant harvesting and processing, crop mix analysis, air circulation and atmosphere contaminant flow subsystems, thermal control considerations, utility routing including accessibility and maintenance, and nutrient subsystem design.
Preliminary design report for OTEC stationkeeping subsystems (SKSS)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1979-12-12
Lockheed Ocean Systems with IMODCO prepared these preliminary designs for OTEC Stationkeeping Subsystems (SKSS) under contract to NOAA in support of the Department of Energy OTEC program. The results of Tasks III, V, and VI are presented in this design report. The report consists of five sections: introduction, preliminary designs for the multiple anchor leg (MAL) and tension anchor leg (TAL), costs and schedule, and conclusions. Extensive appendixes provide detailed descriptions of design methodology and include backup calculations and data to support the results presented. The objective of this effort is to complete the preliminary designs for the barge-MAL andmore » Spar-TAL SKSS. A set of drawings is provided for each which show arrangements, configuration, component details, engineering description, and deployment plan. Loads analysis, performance assessment, and sensitivity to requirements are presented, together with the methodology employed to analyze the systems and to derive the results presented. Life cycle costs and schedule are prepared and compared on a common basis. Finally, recommendations for the Commercial Plant SKSS are presented for both platform types.« less
Overview of SDCM - The Spacecraft Design and Cost Model
NASA Technical Reports Server (NTRS)
Ferebee, Melvin J.; Farmer, Jeffery T.; Andersen, Gregory C.; Flamm, Jeffery D.; Badi, Deborah M.
1988-01-01
The Spacecraft Design and Cost Model (SDCM) is a computer-aided design and analysis tool for synthesizing spacecraft configurations, integrating their subsystems, and generating information concerning on-orbit servicing and costs. SDCM uses a bottom-up method in which the cost and performance parameters for subsystem components are first calculated; the model then sums the contributions from individual components in order to obtain an estimate of sizes and costs for each candidate configuration within a selected spacecraft system. An optimum spacraft configuration can then be selected.
PHENIX Work Breakdown Structure. Cost and schedule review copy
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1994-02-01
The Work Breakdown Structure (WBS) Book begins with this Overview section, which contains the high-level summary cost estimate, the cost profile, and the global construction schedule. The summary cost estimate shows the total US cost and the cost in terms of PHENIX construction funds for building the PHENIX detector. All costs in the WBS book are shown in FY 1993 dollars. Also shown are the institutional and foreign contributions, the level of pre-operations funding, and the cost of deferred items. Pie charts are presented at PHENIX WBS level 1 and 2 that show this information. The PHENIX construction funds aremore » shown broken down to PHENIX WBS level 3 items per fiscal year, and the resulting profile is compared to the RHIC target profile. An accumulated difference of the two profiles is also shown. The PHENIX global construction schedule is presented at the end of the Overview section. Following the Overview are sections for each subsystem. Each subsystem section begins with a summary cost estimate, cost profile, and critical path. The total level 3 cost is broken down into fixed costs (M&S), engineering costs (EDIA) and labor costs. Costs are further broken down in terms of PHENIX construction funds, institutional and foreign contributions, pre-operations funding, and deferred items. Also shown is the contingency at level 3 and the level 4 breakdown of the total cost. The cost profile in fiscal years is shown at level 3. The subsystem summaries are followed by the full cost estimate and schedule sheets for that subsystem. These detailed sheets are typically carried down to level 7 or 8. The cost estimate shows Total, M&S, EDIA, and Labor breakdowns, as well as contingency, for each WBS entry.« less
Cost-effective data storage/archival subsystem for functional PACS
NASA Astrophysics Data System (ADS)
Chen, Y. P.; Kim, Yongmin
1993-09-01
Not the least of the requirements of a workable PACS is the ability to store and archive vast amounts of information. A medium-size hospital will generate between 1 and 2 TBytes of data annually on a fully functional PACS. A high-speed image transmission network coupled with a comparably high-speed central data storage unit can make local memory and magnetic disks in the PACS workstations less critical and, in an extreme case, unnecessary. Under these circumstances, the capacity and performance of the central data storage subsystem and database is critical in determining the response time at the workstations, thus significantly affecting clinical acceptability. The central data storage subsystem not only needs to provide sufficient capacity to store about ten days worth of images (five days worth of new studies, and on the average, about one comparison study for each new study), but also supplies images to the requesting workstation in a timely fashion. The database must provide fast retrieval responses upon users' requests for images. This paper analyzes both advantages and disadvantages of multiple parallel transfer disks versus RAID disks for short-term central data storage subsystem, as well as optical disk jukebox versus digital recorder tape subsystem for long-term archive. Furthermore, an example high-performance cost-effective storage subsystem which integrates both the RAID disks and high-speed digital tape subsystem as a cost-effective PACS data storage/archival unit are presented.
Reliability-based management of buried pipelines considering external corrosion defects
NASA Astrophysics Data System (ADS)
Miran, Seyedeh Azadeh
Corrosion is one of the main deteriorating mechanisms that degrade the energy pipeline integrity, due to transferring corrosive fluid or gas and interacting with corrosive environment. Corrosion defects are usually detected by periodical inspections using in-line inspection (ILI) methods. In order to ensure pipeline safety, this study develops a cost-effective maintenance strategy that consists of three aspects: corrosion growth model development using ILI data, time-dependent performance evaluation, and optimal inspection interval determination. In particular, the proposed study is applied to a cathodic protected buried steel pipeline located in Mexico. First, time-dependent power-law formulation is adopted to probabilistically characterize growth of the maximum depth and length of the external corrosion defects. Dependency between defect depth and length are considered in the model development and generation of the corrosion defects over time is characterized by the homogenous Poisson process. The growth models unknown parameters are evaluated based on the ILI data through the Bayesian updating method with Markov Chain Monte Carlo (MCMC) simulation technique. The proposed corrosion growth models can be used when either matched or non-matched defects are available, and have ability to consider newly generated defects since last inspection. Results of this part of study show that both depth and length growth models can predict damage quantities reasonably well and a strong correlation between defect depth and length is found. Next, time-dependent system failure probabilities are evaluated using developed corrosion growth models considering prevailing uncertainties where three failure modes, namely small leak, large leak and rupture are considered. Performance of the pipeline is evaluated through failure probability per km (or called a sub-system) where each subsystem is considered as a series system of detected and newly generated defects within that sub-system. Sensitivity analysis is also performed to determine to which incorporated parameter(s) in the growth models reliability of the studied pipeline is most sensitive. The reliability analysis results suggest that newly generated defects should be considered in calculating failure probability, especially for prediction of long-term performance of the pipeline and also, impact of the statistical uncertainty in the model parameters is significant that should be considered in the reliability analysis. Finally, with the evaluated time-dependent failure probabilities, a life cycle-cost analysis is conducted to determine optimal inspection interval of studied pipeline. The expected total life-cycle costs consists construction cost and expected costs of inspections, repair, and failure. The repair is conducted when failure probability from any described failure mode exceeds pre-defined probability threshold after each inspection. Moreover, this study also investigates impact of repair threshold values and unit costs of inspection and failure on the expected total life-cycle cost and optimal inspection interval through a parametric study. The analysis suggests that a smaller inspection interval leads to higher inspection costs, but can lower failure cost and also repair cost is less significant compared to inspection and failure costs.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
The Work Breakdown Structure (WBS) Book begins with this Overview section, which contains the high-level summary cost estimate, the cost profile, and the global construction schedule. The summary cost estimate shows the total US cost and the cost in terms of PHENIX construction funds for building the PHENIX detector. All costs in the WBS book are shown in FY 1993 dollars. Also shown are the institutional and foreign contributions, the level of pre-operations funding, and the cost of deferred items. Pie charts are presented at PHENIX WBS level 1 and 2 that show this information. The PHENIX construction funds aremore » shown broken down to PHENIX WBS level 3 items per fiscal year, and the resulting profile is compared to the RHIC target profile. An accumulated difference of the two profiles is also shown. The PHENIX global construction schedule is presented at the end of the Overview section. Following the Overview are sections for each subsystem. Each subsystem section begins with a summary cost estimate, cost profile, and critical path. The total level 3 cost is broken down into fixed costs (M&S), engineering costs (EDIA) and labor costs. Costs are further broken down in terms of PHENIX construction funds, institutional and foreign contributions, pre-operations funding, and deferred items. Also shown is the contingency at level 3 and the level 4 breakdown of the total cost. The cost profile in fiscal years is shown at level 3. The subsystem summaries are followed by the full cost estimate and schedule sheets for that subsystem. These detailed sheets are typically carried down to level 7 or 8. The cost estimate Total, M&S, EDIA, and Labor breakdowns, as well as contingency, for each WBS entry.« less
2nd & 3rd Generation Vehicle Subsystems
NASA Technical Reports Server (NTRS)
2000-01-01
This paper contains viewgraph presentation on the "2nd & 3rd Generation Vehicle Subsystems" project. The objective behind this project is to design, develop and test advanced avionics, power systems, power control and distribution components and subsystems for insertion into a highly reliable and low-cost system for a Reusable Launch Vehicles (RLV). The project is divided into two sections: 3rd Generation Vehicle Subsystems and 2nd Generation Vehicle Subsystems. The following topics are discussed under the first section, 3rd Generation Vehicle Subsystems: supporting the NASA RLV program; high-performance guidance & control adaptation for future RLVs; Evolvable Hardware (EHW) for 3rd generation avionics description; Scaleable, Fault-tolerant Intelligent Network or X(trans)ducers (SFINIX); advance electric actuation devices and subsystem technology; hybrid power sources and regeneration technology for electric actuators; and intelligent internal thermal control. Topics discussed in the 2nd Generation Vehicle Subsystems program include: design, development and test of a robust, low-maintenance avionics with no active cooling requirements and autonomous rendezvous and docking systems; design and development of a low maintenance, high reliability, intelligent power systems (fuel cells and battery); and design of a low cost, low maintenance high horsepower actuation systems (actuators).
Modular experimental platform for science and applications
NASA Technical Reports Server (NTRS)
Hill, A. S.
1984-01-01
A modularized, standardized spacecraft bus, known as MESA, suitable for a variety of science and applications missions is discussed. The basic bus consists of a simple structural arrangement housing attitude control, telemetry/command, electrical power, propulsion and thermal control subsystems. The general arrangement allows extensive subsystem adaptation to mission needs. Kits provide for the addition of tape recorders, increased power levels and propulsion growth. Both 3-axis and spin stabilized flight proven attitude control subsystems are available. The MESA bus can be launched on Ariane, as a secondary payload for low cost, or on the STS with a PAM-D or other suitable upper stage. Multi-spacecraft launches are possible with either booster. Launch vehicle integration is simple and cost-effective. The low cost of the MESA bus is achieved by the extensive utilization of existing subsystem design concepts and equipment, and efficient program management and test integration techniques.
Structural Probability Concepts Adapted to Electrical Engineering
NASA Technical Reports Server (NTRS)
Steinberg, Eric P.; Chamis, Christos C.
1994-01-01
Through the use of equivalent variable analogies, the authors demonstrate how an electrical subsystem can be modeled by an equivalent structural subsystem. This allows the electrical subsystem to be probabilistically analyzed by using available structural reliability computer codes such as NESSUS. With the ability to analyze the electrical subsystem probabilistically, we can evaluate the reliability of systems that include both structural and electrical subsystems. Common examples of such systems are a structural subsystem integrated with a health-monitoring subsystem, and smart structures. Since these systems have electrical subsystems that directly affect the operation of the overall system, probabilistically analyzing them could lead to improved reliability and reduced costs. The direct effect of the electrical subsystem on the structural subsystem is of secondary order and is not considered in the scope of this work.
Cost analysis of oxygen recovery systems
NASA Technical Reports Server (NTRS)
Yakut, M. M.
1973-01-01
Report is made of the cost analysis of four leading oxygen recovery subsystems which include two carbon dioxide reduction subsystems and two water electrolysis subsystems, namely, the solid polymer electrolyte and the circulating KOH electrolyte. The four oxygen recovery systems were quantitatively evaluated. System characteristics, including process flows, performance, and physical characteristics were also analyzed. Additionally, the status of development of each of the systems considered and the required advance technology efforts required to bring conceptual and/or pre-prototype hardware to an operational prototype status were defined. Intimate knowledge of the operations, development status, and capabilities of the systems to meet space mission requirements were found to be essential in establishing the cost estimating relationships for advanced life support systems.
Advanced vehicle systems assessment. Volume 2: Subsystems assessment
NASA Technical Reports Server (NTRS)
Hardy, K.
1985-01-01
Volume 2 (Subsystems Assessment) is part of a five-volume report entitled Advanced Vehicle Systems Assessment. Volume 2 presents the projected performance capabilities and cost characteristics of applicable subsystems, considering an additional decade of development. Subsystems of interest include energy storage and conversion devices as well as the necessary powertrain components and vehicle subsystems. Volume 2 also includes updated battery information based on the assessment of an independent battery review board (with the aid of subcontractor reports on advanced battery characteristics).
NASA Technical Reports Server (NTRS)
Bien, D. D.
1973-01-01
This analysis considers the optimum allocation of redundancy in a system of serially connected subsystems in which each subsystem is of the k-out-of-n type. Redundancy is optimally allocated when: (1) reliability is maximized for given costs; or (2) costs are minimized for given reliability. Several techniques are presented for achieving optimum allocation and their relative merits are discussed. Approximate solutions in closed form were attainable only for the special case of series-parallel systems and the efficacy of these approximations is discussed.
Lunar Surface-to-Surface Power Transfer
NASA Technical Reports Server (NTRS)
Kerslake, Thomas W.
2007-01-01
A human lunar outpost, under NASA study for construction in the 2020's, has potential requirements to transfer electric power up to 50-kW across the lunar surface from 0.1 to 10-km distances. This power would be used to operate surface payloads located remotely from the outpost and/or outpost primary power grid. This paper describes concept designs for state-of-the-art technology power transfer subsystems including AC or DC power via cables, beamed radio frequency power and beamed laser power. Power transfer subsystem mass and performance are calculated and compared for each option. A simplified qualitative assessment of option operations, hazards, costs and technology needs is also described. Based on these concept designs and performance analyses, a DC power cabling subsystem is recommended to minimize subsystem mass and to minimize mission and programmatic costs and risks. Avenues for additional power transfer subsystem studies are recommended.
Spectral and Polarization Sensitivity of the Dipteran Visual System
McCann, Gilbert D.; Arnett, David W.
1972-01-01
Spectral and polarization sensitivity measurements were made at several levels (retina, first and third optic ganglion, cervical connective, behavior) of the dipteran visual nervous system. At all levels, it was possible to reveal contributions from the retinular cell subsystem cells 1 to 6 or the retinular cell subsystem cells 7 and 8 or both. Only retinular cells 1 to 6 were directly studied, and all possessed the same spectral sensitivity characterized by two approximately equal sensitivity peaks at 350 and 480 nm. All units of both the sustaining and on-off variety in the first optic ganglion exhibited the same spectral sensitivity as that of retinular cells 1 to 6. It was possible to demonstrate for motion detection and optomotor responses two different spectral sensitivities depending upon the spatial wavelength of the stimulus. For long spatial wavelengths, the spectral sensitivity agreed with retinular cells 1 to 6; however, the spectral sensitivity at short spatial wavelengths was characterized by a single peak at 465 nm reflecting contributions from the (7, 8) subsystem. Although the two subsystems exhibited different spectral sensitivities, the difference was small and no indication of color discrimination mechanisms was observed. Although all retinular cells 1 to 6 exhibited a preferred polarization plane, sustaining and on-off units did not. Likewise, motion detection and optomotor responses were insensitive to the polarization plane for long spatial wavelength stimuli; however, sensitivity to select polarization planes was observed for short spatial wavelengths. PMID:5027759
49 CFR Appendix B to Part 236 - Risk Assessment Criteria
Code of Federal Regulations, 2012 CFR
2012-10-01
... availability calculations for subsystems and components, Fault Tree Analysis (FTA) of the subsystems, and... upper bound, as estimated with a sensitivity analysis, and the risk value selected must be demonstrated... interconnected subsystems/components? The risk assessment of each safety-critical system (product) must account...
49 CFR Appendix B to Part 236 - Risk Assessment Criteria
Code of Federal Regulations, 2014 CFR
2014-10-01
... availability calculations for subsystems and components, Fault Tree Analysis (FTA) of the subsystems, and... upper bound, as estimated with a sensitivity analysis, and the risk value selected must be demonstrated... interconnected subsystems/components? The risk assessment of each safety-critical system (product) must account...
Solar photovoltaic power stations
NASA Technical Reports Server (NTRS)
Chowaniec, C. R.; Pittman, P. F.; Ferber, R. R.; Marshall, B. W.
1977-01-01
The subsystems of a solar photovoltaic central power system are identified and the cost of major components are estimated. The central power system, which would have a peak power capability in the range of 50 to 1000 MW, utilizes two types of subsystems - a power conditioner and a solar array. Despite differences in costs of inverters, the overall cost of the total power conditioning subsystem is about the same for all approaches considered. A combination of two inverters operating from balanced dc buses as a pair of 6-pulse groups is recommended. A number of different solar cell modules and tracking array structures were analyzed. It is concluded that when solar cell costs are high (greater than $500/kW), high concentration modules are more cost effective than those with low concentration. Vertical-axis tracking is the most effective of the studied tracking modes. For less expensive solar cells (less than $400/kW), fixed tilt collector/reflector modules are more cost effective than those which track.
NASA Technical Reports Server (NTRS)
1985-01-01
Fundamentally, the volumes of the oxidizer and fuel propellant scavenged from the orbiter and external tank determine the size and weight of the scavenging system. The optimization of system dimensions and weights is stimulated by the requirement to minimize the use of partial length of the orbiter payload bay. Thus, the cost estimates begin with weights established for the optimum design. Both the design, development, test, and evaluation and theoretical first unit hardware production costs are estimated from parametric cost weight scaling relations for four subsystems. For cryogenic propellants, the widely differing characteristics of the oxidizer and the fuel lead to two separate tank subsystems, in addition to the electrical and instrumentation subsystems. Hardwares costs also involve quantity, as an independent variable, since the number of production scavenging systems is not firm. For storable propellants, since the tankage volume of the oxidizer and fuel are equal, the hardware production costs for developing these systems are lower than for cryogenic propellants.
Space transportation architecture: Reliability sensitivities
NASA Technical Reports Server (NTRS)
Williams, A. M.
1992-01-01
A sensitivity analysis is given of the benefits and drawbacks associated with a proposed Earth to orbit vehicle architecture. The architecture represents a fleet of six vehicles (two existing, four proposed) that would be responsible for performing various missions as mandated by NASA and the U.S. Air Force. Each vehicle has a prescribed flight rate per year for a period of 31 years. By exposing this fleet of vehicles to a probabilistic environment where the fleet experiences failures, downtimes, setbacks, etc., the analysis involves determining the resiliency and costs associated with the fleet of specific vehicle/subsystem reliabilities. The resources required were actual observed data on the failures and downtimes associated with existing vehicles, data based on engineering judgement for proposed vehicles, and the development of a sensitivity analysis program.
NASA Astrophysics Data System (ADS)
Mehrpooya, Mehdi; Ansarinasab, Hojat; Moftakhari Sharifzadeh, Mohammad Mehdi; Rosen, Marc A.
2017-10-01
An integrated power plant with a net electrical power output of 3.71 × 105 kW is developed and investigated. The electrical efficiency of the process is found to be 60.1%. The process includes three main sub-systems: molten carbonate fuel cell system, heat recovery section and cryogenic carbon dioxide capturing process. Conventional and advanced exergoeconomic methods are used for analyzing the process. Advanced exergoeconomic analysis is a comprehensive evaluation tool which combines an exergetic approach with economic analysis procedures. With this method, investment and exergy destruction costs of the process components are divided into endogenous/exogenous and avoidable/unavoidable parts. Results of the conventional exergoeconomic analyses demonstrate that the combustion chamber has the largest exergy destruction rate (182 MW) and cost rate (13,100 /h). Also, the total process cost rate can be decreased by reducing the cost rate of the fuel cell and improving the efficiency of the combustion chamber and heat recovery steam generator. Based on the total avoidable endogenous cost rate, the priority for modification is the heat recovery steam generator, a compressor and a turbine of the power plant, in rank order. A sensitivity analysis is done to investigate the exergoeconomic factor parameters through changing the effective parameter variations.
NASA Technical Reports Server (NTRS)
Stebbins, Robin T.
2009-01-01
The LISA science requirements and conceptual design have been fairly stable for over a decade. In the interest of reducing costs, the LISA Project at NASA has looked for simplifications of the architecture, at downsizing of subsystems, and at descopes of the entire mission. This is a natural activity of the formulation phase, and one that is particularly timely in the current NASA budgetary context. There is, and will continue to be, enormous pressure for cost reduction from both ESA and NASA, reviewers and the broader research community. Here, the rationale for the baseline architecture is reviewed, and recent efforts to find simplifications and other reductions that might lead to savings are reported. A few possible simplifications have been found in the LISA baseline architecture. In the interest of exploring cost sensitivity, one moderate and one aggressive descope have been evaluated; the cost savings are modest and the loss of science is not.
TOPEX satellite concept. TOPEX option study report
NASA Technical Reports Server (NTRS)
Meyer, D. P.; Case, C. M.
1982-01-01
Candidate bus equipment from the Viking, Applications Explorer Mission, and Small Scientific Satellite programs for application to the TOPEX mission options is assessed. Propulsion module equipment and subsystem candidates from the Applications Explorer Mission satellites and the Small Scientific Satellite spacecraft are evaluated for those TOPEX options. Several subsystem concepts appropriate to the TOPEX options are described. These descriptions consider performance characteristics of the subsystems. Cost and availability information on the candidate equipment and subsystems are also provided.
NASA Technical Reports Server (NTRS)
1976-01-01
All possible overall system configurations, operating modes, and subsystem concepts for a wind turbine configuration for cost effective generation of electrical power were evaluated for both technical feasibility and compatibility with utility networks, as well as for economic attractiveness. A design optimization computer code was developed to determine the cost sensitivity of the various design features, and thus establish the configuration and design conditions that would minimize the generated energy costs. The preliminary designs of both a 500 kW unit and a 1500 kW unit operating in a 12 mph and 18 mph median wind speed respectively, were developed. The various design features and components evaluated are described, and the rationale employed to select the final design configuration is given. All pertinent technical performance data and component cost data is included. The costs of all major subassemblies are estimated and the resultant energy costs for both the 500 kW and 1500 kW units are calculated.
Comparing NASA and ESA Cost Estimating Methods for Human Missions to Mars
NASA Technical Reports Server (NTRS)
Hunt, Charles D.; vanPelt, Michel O.
2004-01-01
To compare working methodologies between the cost engineering functions in NASA Marshall Space Flight Center (MSFC) and ESA European Space Research and Technology Centre (ESTEC), as well as to set-up cost engineering capabilities for future manned Mars projects and other studies which involve similar subsystem technologies in MSFC and ESTEC, a demonstration cost estimate exercise was organized. This exercise was a direct way of enhancing not only cooperation between agencies but also both agencies commitment to credible cost analyses. Cost engineers in MSFC and ESTEC independently prepared life-cycle cost estimates for a reference human Mars project and subsequently compared the results and estimate methods in detail. As a non-sensitive, public domain reference case for human Mars projects, the Mars Direct concept was chosen. In this paper the results of the exercise are shown; the differences and similarities in estimate methodologies, philosophies, and databases between MSFC and ESTEC, as well as the estimate results for the Mars Direct concept. The most significant differences are explained and possible estimate improvements identified. In addition, the Mars Direct plan and the extensive cost breakdown structure jointly set-up by MSFC and ESTEC for this concept are presented. It was found that NASA applied estimate models mainly based on historic Apollo and Space Shuttle cost data, taking into account the changes in technology since then. ESA used models mostly based on European satellite and launcher cost data, taking into account the higher equipment and testing standards for human space flight. Most of NASA's and ESA s estimates for the Mars Direct case are comparable, but there are some important, consistent differences in the estimates for: 1) Large Structures and Thermal Control subsystems; 2) System Level Management, Engineering, Product Assurance and Assembly, Integration and Test/Verification activities; 3) Mission Control; 4) Space Agency Program Level activities.
ERIC Educational Resources Information Center
Lintz, Larry M.; And Others
A study investigated the relationship between avionics subsystem design characteristics and training time, training cost, and job performance. A list of design variables believed to affect training and job performance was established and supplemented with personnel variables, including aptitude test scores and the amount of training and…
Space power subsystem automation technology
NASA Technical Reports Server (NTRS)
Graves, J. R. (Compiler)
1982-01-01
The technology issues involved in power subsystem automation and the reasonable objectives to be sought in such a program were discussed. The complexities, uncertainties, and alternatives of power subsystem automation, along with the advantages from both an economic and a technological perspective were considered. Whereas most spacecraft power subsystems now use certain automated functions, the idea of complete autonomy for long periods of time is almost inconceivable. Thus, it seems prudent that the technology program for power subsystem automation be based upon a growth scenario which should provide a structured framework of deliberate steps to enable the evolution of space power subsystems from the current practice of limited autonomy to a greater use of automation with each step being justified on a cost/benefit basis. Each accomplishment should move toward the objectives of decreased requirement for ground control, increased system reliability through onboard management, and ultimately lower energy cost through longer life systems that require fewer resources to operate and maintain. This approach seems well-suited to the evolution of more sophisticated algorithms and eventually perhaps even the use of some sort of artificial intelligence. Multi-hundred kilowatt systems of the future will probably require an advanced level of autonomy if they are to be affordable and manageable.
Model reduction for Space Station Freedom
NASA Technical Reports Server (NTRS)
Williams, Trevor
1992-01-01
Model reduction is an important practical problem in the control of flexible spacecraft, and a considerable amount of work has been carried out on this topic. Two of the best known methods developed are modal truncation and internal balancing. Modal truncation is simple to implement but can give poor results when the structure possesses clustered natural frequencies, as often occurs in practice. Balancing avoids this problem but has the disadvantages of high computational cost, possible numerical sensitivity problems, and no physical interpretation for the resulting balanced 'modes'. The purpose of this work is to examine the performance of the subsystem balancing technique developed by the investigator when tested on a realistic flexible space structure, in this case a model of the Permanently Manned Configuration (PMC) of Space Station Freedom. This method retains the desirable properties of standard balancing while overcoming the three difficulties listed above. It achieves this by first decomposing the structural model into subsystems of highly correlated modes. Each subsystem is approximately uncorrelated from all others, so balancing them separately and then combining yields comparable results to balancing the entire structure directly. The operation count reduction obtained by the new technique is considerable: a factor of roughly r(exp 2) if the system decomposes into r equal subsystems. Numerical accuracy is also improved significantly, as the matrices being operated on are of reduced dimension, and the modes of the reduced-order model now have a clear physical interpretation; they are, to first order, linear combinations of repeated-frequency modes.
Newman Unit 1 advanced solar repowering advanced conceptual design. Final report
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
1982-04-01
The Newman Unit 1 solar repowering design is a water/steam central receiver concept supplying superheated steam. The work reported is to develop a refined baseline conceptual design that has potential for construction and operation by 1986, makes use of existing solar thermal technology, and provides the best economics for this application. Trade studies performed in the design effort are described, both for the conceptual design of the overall system and for the subsystem conceptual design. System-level functional requirements, design, operation, performance, cost, safety, environmental, institutional, and regulatory considerations are described. Subsystems described include the collector, receiver, fossil energy, electrical powermore » generating, and master control subsystems, site and site facilities. The conceptual design, cost, and performance of each subsystem is discussed at length. A detailed economic analysis of the repowered unit is made to realistically assess the economics of the first repowered unit using present cost data for a limited production level for solar hardware. Finally, a development plan is given, including the design, procurement, construction, checkout, startup, performance validation, and commercial operation. (LEW)« less
Dedicated nuclear facilities for electrolytic hydrogen production
NASA Technical Reports Server (NTRS)
Foh, S. E.; Escher, W. J. D.; Donakowski, T. D.
1979-01-01
An advanced technology, fully dedicated nuclear-electrolytic hydrogen production facility is presented. This plant will produce hydrogen and oxygen only and no electrical power will be generated for off-plant use. The conceptual design was based on hydrogen production to fill a pipeline at 1000 psi and a 3000 MW nuclear base, and the base-line facility nuclear-to-shaftpower and shaftpower-to-electricity subsystems, the water treatment subsystem, electricity-to-hydrogen subsystem, hydrogen compression, efficiency, and hydrogen production cost are discussed. The final conceptual design integrates a 3000 MWth high-temperature gas-cooled reactor operating at 980 C helium reactor-out temperature, direct dc electricity generation via acyclic generators, and high-current density, high-pressure electrolyzers based on the solid polymer electrolyte approach. All subsystems are close-coupled and optimally interfaced and pipeline hydrogen is produced at 1000 psi. Hydrogen costs were about half of the conventional nuclear electrolysis process.
Electric and hybrid vehicle environmental control subsystem study
NASA Technical Reports Server (NTRS)
Heitner, K. L.
1980-01-01
An environmental control subsystem (ECS) in electric and hybrid vehicles is studied. A combination of a combustion heater and gasoline engine (Otto cycle) driven vapor compression air conditioner is selected. The combustion heater, the small gasoline engine, and the vapor compression air conditioner are commercially available. These technologies have good cost and performance characteristics. The cost for this ECS is relatively close to the cost of current ECS's. Its effect on the vehicle's propulsion battery is minimal and the ECS size and weight do not have significant impact on the vehicle's range.
An Assessment of Smallsat Technology to Future Exploration Missions
NASA Technical Reports Server (NTRS)
Chan, Steve
1997-01-01
This reports the results of a general study for NASA Lewis in relation to the use of small satellites for a Mars Relay Satellite (MRS) that supports communications between Mars and Earth: commands to, and telemetry from, Mars Landers and Rover. The scope of the study encompasses a survey of small satellites, those that are lower than 800 kg in mass, by NASA, DoD, and commercial companies. Additionally, surveys in advanced technologies in the area of composite materials, propulsion subsystems, battery subsystems, communications components and subsystems, and ground operations are also provided, A summary of NASA Mars Programs and their status as relevant to MRS is also included. Attempts to draw detailed cost conclusion is generally not possible due to its proprietary nature. In any event, cost is driven by market demands rather than new technologies. A preliminary comparison with the cost estimate of the S-Tel/OSC report did suggest the possibility of cost savings for the MRS by the use of production busses. On the other hand, cost savings in normalized terms from the use of automated ground systems were obtained with some degree of details.
NASA Technical Reports Server (NTRS)
Kimsey, D. B.
1978-01-01
The effect on the life cycle cost of the timing subsystem was examined, when these optional features were included in various combinations. The features included mutual control, directed control, double-ended reference links, independence of clock error measurement and correction, phase reference combining, self-organization, smoothing for link and nodal dropouts, unequal reference weightings, and a master in a mutual control network. An overall design of a microprocessor-based timing subsystem was formulated. The microprocessor (8080) implements the digital filter portion of a digital phase locked loop, as well as other control functions such as organization of the network through communication with processors at neighboring nodes.
NASA Technical Reports Server (NTRS)
1973-01-01
Power subsystem cost/weight tradeoffs are discussed for the Venus probe spacecraft. The cost estimations of power subsystem units were based upon DSCS-2, DSP, and Pioneer 10 and 11 hardware design and development and manufacturing experience. Parts count and degree of modification of existing hardware were factored into the estimate of manufacturing and design and development costs. Cost data includes sufficient quantities of units to equip probe bus and orbiter versions. It was based on the orbiter complement of equipment, but the savings in fewer slices for the probe bus balance the cost of the different probe bus battery. The preferred systems for the Thor/Delta and for the Atlas/Centaur are discussed. The weights of the candidate designs were based upon slice or tray weights for functionally equivalent circuitry measured on existing hardware such as Pioneers 10 and 11, Intelsat 3, DSCS-2, or DSP programs. Battery weights were based on measured cell weight data adjusted for case weight or off-the-shelf battery weights. The solar array weight estimate was based upon recent hardware experience on DSCS-2 and DSP arrays.
Fuzzy/Neural Software Estimates Costs of Rocket-Engine Tests
NASA Technical Reports Server (NTRS)
Douglas, Freddie; Bourgeois, Edit Kaminsky
2005-01-01
The Highly Accurate Cost Estimating Model (HACEM) is a software system for estimating the costs of testing rocket engines and components at Stennis Space Center. HACEM is built on a foundation of adaptive-network-based fuzzy inference systems (ANFIS) a hybrid software concept that combines the adaptive capabilities of neural networks with the ease of development and additional benefits of fuzzy-logic-based systems. In ANFIS, fuzzy inference systems are trained by use of neural networks. HACEM includes selectable subsystems that utilize various numbers and types of inputs, various numbers of fuzzy membership functions, and various input-preprocessing techniques. The inputs to HACEM are parameters of specific tests or series of tests. These parameters include test type (component or engine test), number and duration of tests, and thrust level(s) (in the case of engine tests). The ANFIS in HACEM are trained by use of sets of these parameters, along with costs of past tests. Thereafter, the user feeds HACEM a simple input text file that contains the parameters of a planned test or series of tests, the user selects the desired HACEM subsystem, and the subsystem processes the parameters into an estimate of cost(s).
NASA Astrophysics Data System (ADS)
Brockmann, Axel; Brückner, Dorothea
2001-01-01
Male insects that are attracted by sex pheromones to find their female mates over long distances have specialized olfactory subsystems. Morphologically, these subsystems are characterized by a large number of receptor neurons sensitive to components of the female's pheromones and hypertrophied glomerular subunits ('macroglomeruli' or 'macroglomerular complexes') in the antennal lobes, in which the axons of the receptor neurons converge. The olfactory subsystems are adapted for an increased sensitivity to perceive minute amounts of pheromones. In Apis mellifera, drones have 18,600 olfactory poreplate sensilla per antenna, each equipped with receptor neurons sensitive to the queen's sex pheromone, and four voluminous macroglomeruli (MG1-MG4) in the antennal lobes. In contrast, we show that drones of the phylogenetically distant species, Apis florea, have only 1,200 poreplate sensilla per antenna and only two macroglomeruli in their antennal lobes. These macroglomeruli are homologous in anatomical position to the two most prominent macroglomeruli in A. mellifera, the MG1 and MG2, but they are much smaller in size. The morphological and anatomical differences described here suggest major modifications in the sex-pheromone processing subsystem of both species: (1) less pheromone sensitivity in A. florea and (2) a more complex sex-pheromone processing and thus a more complex sex-pheromone communication in A. mellifera.
McLaren, D G; Buchanan, D S; Williams, J E
1987-10-01
A static, deterministic computer model, programmed in Microsoft Basic for IBM PC and Apple Macintosh computers, was developed to calculate production efficiency (cost per kg of product) for nine alternative types of crossbreeding system involving four breeds of swine. The model simulates efficiencies for four purebred and 60 alternative two-, three- and four-breed rotation, rotaterminal, backcross and static cross systems. Crossbreeding systems were defined as including all purebred, crossbred and commercial matings necessary to maintain a total of 10,000 farrowings. Driving variables for the model are mean conception rate at first service and for an 8-wk breeding season, litter size born, preweaning survival rate, postweaning average daily gain, feed-to-gain ratio and carcass backfat. Predictions are computed using breed direct genetic and maternal effects for the four breeds, plus individual, maternal and paternal specific heterosis values, input by the user. Inputs required to calculate the number of females farrowing in each sub-system include the proportion of males and females replaced each breeding cycle in purebred and crossbred populations, the proportion of male and female offspring in seedstock herds that become breeding animals, and the number of females per boar. Inputs required to calculate the efficiency of terminal production (cost-to-product ratio) for each sub-system include breeding herd feed intake, gilt development costs, feed costs and labor and overhead costs. Crossbreeding system efficiency is calculated as the weighted average of sub-system cost-to-product ratio values, weighting by the number of females farrowing in each sub-system.
McCord, Gordon C; Liu, Anne; Singh, Prabhjot
2013-04-01
To provide cost guidance for developing a locally adaptable and nationally scalable community health worker (CHW) system within primary-health-care systems in sub-Saharan Africa. The yearly costs of training, equipping and deploying CHWs throughout rural sub-Saharan Africa were calculated using data from the literature and from the Millennium Villages Project. Model assumptions were such as to allow national governments to adapt the CHW subsystem to national needs and to deploy an average of 1 CHW per 650 rural inhabitants by 2015. The CHW subsystem described was costed by employing geographic information system (GIS) data on population, urban extents, national and subnational disease prevalence, and unit costs (from the field for wages and commodities). The model is easily replicable and configurable. Countries can adapt it to local prices, wages, population density and disease burdens in different geographic areas. The average annual cost of deploying CHWs to service the entire sub-Saharan African rural population by 2015 would be approximately 2.6 billion (i.e. 2600 million) United States dollars (US$). This sum, to be covered both by national governments and by donor partners, translates into US$ 6.86 per year per inhabitant covered by the CHW subsystem and into US$ 2.72 per year per inhabitant. Alternatively, it would take an annual average of US$ 3750 to train, equip and support each CHW. Comprehensive CHW subsystems can be deployed across sub-Saharan Africa at cost that is modest compared with the projected costs of the primary-health-care system. Given their documented successes, they offer a strong complement to facility-based care in rural African settings.
McCord, Gordon C; Liu, Anne
2013-01-01
Abstract Objective To provide cost guidance for developing a locally adaptable and nationally scalable community health worker (CHW) system within primary-health-care systems in sub-Saharan Africa. Methods The yearly costs of training, equipping and deploying CHWs throughout rural sub-Saharan Africa were calculated using data from the literature and from the Millennium Villages Project. Model assumptions were such as to allow national governments to adapt the CHW subsystem to national needs and to deploy an average of 1 CHW per 650 rural inhabitants by 2015. The CHW subsystem described was costed by employing geographic information system (GIS) data on population, urban extents, national and subnational disease prevalence, and unit costs (from the field for wages and commodities). The model is easily replicable and configurable. Countries can adapt it to local prices, wages, population density and disease burdens in different geographic areas. Findings The average annual cost of deploying CHWs to service the entire sub-Saharan African rural population by 2015 would be approximately 2.6 billion (i.e. 2600 million) United States dollars (US$). This sum, to be covered both by national governments and by donor partners, translates into US$ 6.86 per year per inhabitant covered by the CHW subsystem and into US$ 2.72 per year per inhabitant. Alternatively, it would take an annual average of US$ 3750 to train, equip and support each CHW. Conclusion Comprehensive CHW subsystems can be deployed across sub-Saharan Africa at cost that is modest compared with the projected costs of the primary-health-care system. Given their documented successes, they offer a strong complement to facility-based care in rural African settings. PMID:23599547
Weight and cost forecasting for advanced manned space vehicles
NASA Technical Reports Server (NTRS)
Williams, Raymond
1989-01-01
A mass and cost estimating computerized methology for predicting advanced manned space vehicle weights and costs was developed. The user friendly methology designated MERCER (Mass Estimating Relationship/Cost Estimating Relationship) organizes the predictive process according to major vehicle subsystem levels. Design, development, test, evaluation, and flight hardware cost forecasting is treated by the study. This methodology consists of a complete set of mass estimating relationships (MERs) which serve as the control components for the model and cost estimating relationships (CERs) which use MER output as input. To develop this model, numerous MER and CER studies were surveyed and modified where required. Additionally, relationships were regressed from raw data to accommodate the methology. The models and formulations which estimated the cost of historical vehicles to within 20 percent of the actual cost were selected. The result of the research, along with components of the MERCER Program, are reported. On the basis of the analysis, the following conclusions were established: (1) The cost of a spacecraft is best estimated by summing the cost of individual subsystems; (2) No one cost equation can be used for forecasting the cost of all spacecraft; (3) Spacecraft cost is highly correlated with its mass; (4) No study surveyed contained sufficient formulations to autonomously forecast the cost and weight of the entire advanced manned vehicle spacecraft program; (5) No user friendly program was found that linked MERs with CERs to produce spacecraft cost; and (6) The group accumulation weight estimation method (summing the estimated weights of the various subsystems) proved to be a useful method for finding total weight and cost of a spacecraft.
Microtechnology in Telecommunications for Spacecraft Cost and Mass Reduction
NASA Technical Reports Server (NTRS)
Herman, M. I.; Burkhart, S.; Crist, R.; Vacchione, J.; Hughes, R.; Kellogg, K.; Kermode, A.; Rascoe, D.; Hornbuckle, C.; Hoffmann, W.;
1994-01-01
This paper examines the incorporation of both microelectronics and micromachining (termed microtechnologies) as applied to deep space telecommunication subsystems. Using the Pluto Fast Flyby Pre-Project as a main case study we have reduced the subsystem mass by 50%.
Code of Federal Regulations, 2011 CFR
2011-10-01
... produce quality systems. This includes ensuring that only necessary and cost-effective requirements are... that involve redesign of systems or subsystems. Life-cycle cost means the total cost to the Government...
Code of Federal Regulations, 2013 CFR
2013-10-01
... produce quality systems. This includes ensuring that only necessary and cost-effective requirements are... that involve redesign of systems or subsystems. Life-cycle cost means the total cost to the Government...
Development costs for a nuclear electric propulsion stage.
NASA Technical Reports Server (NTRS)
Mondt, J. F.; Prickett, W. Z.
1973-01-01
Development costs are presented for an unmanned nuclear electric propulsion (NEP) stage based upon a liquid metal cooled, in-core thermionic reactor. A total of 120 kWe are delivered to the thrust subsystem which employs mercury ion engines for electric propulsion. This study represents the most recent cost evaluation of the development of a reactor power system for a wide range of nuclear space power applications. These include geocentric, and outer planet and other deep space missions. The development program is described for the total NEP stage, based upon specific development programs for key NEP stage components and subsystems.
SDTM - SYSTEM DESIGN TRADEOFF MODEL FOR SPACE STATION FREEDOM RELEASE 1.1
NASA Technical Reports Server (NTRS)
Chamberlin, R. G.
1994-01-01
Although extensive knowledge of space station design exists, the information is widely dispersed. The Space Station Freedom Program (SSFP) needs policies and procedures that ensure the use of consistent design objectives throughout its organizational hierarchy. The System Design Tradeoff Model (SDTM) produces information that can be used for this purpose. SDTM is a mathematical model of a set of possible designs for Space Station Freedom. Using the SDTM program, one can find the particular design which provides specified amounts of resources to Freedom's users at the lowest total (or life cycle) cost. One can also compare alternative design concepts by changing the set of possible designs, while holding the specified user services constant, and then comparing costs. Finally, both costs and user services can be varied simultaneously when comparing different designs. SDTM selects its solution from a set of feasible designs. Feasibility constraints include safety considerations, minimum levels of resources required for station users, budget allocation requirements, time limitations, and Congressional mandates. The total, or life cycle, cost includes all of the U.S. costs of the station: design and development, purchase of hardware and software, assembly, and operations throughout its lifetime. The SDTM development team has identified, for a variety of possible space station designs, the subsystems that produce the resources to be modeled. The team has also developed formulas for the cross consumption of resources by other resources, as functions of the amounts of resources produced. SDTM can find the values of station resources, so that subsystem designers can choose new design concepts that further reduce the station's life cycle cost. The fundamental input to SDTM is a set of formulas that describe the subsystems which make up a reference design. Most of the formulas identify how the resources required by each subsystem depend upon the size of the subsystem. Some of the formulas describe how the subsystem costs depend on size. The formulas can be complicated and nonlinear (if nonlinearity is needed to describe how designs change with size). SDTM's outputs are amounts of resources, life-cycle costs, and marginal costs. SDTM will run on IBM PC/XTs, ATs, and 100% compatibles with 640K of RAM and at least 3Mb of fixed-disk storage. A printer which can print in 132-column mode is also required, and a mathematics co-processor chip is highly recommended. This code is written in Turbo C 2.0. However, since the developers used a modified version of the proprietary Vitamin C source code library, the complete source code is not available. The executable is provided, along with all non-proprietary source code. This program was developed in 1989.
Solar photochemical process engineering for production of fuels and chemicals
NASA Technical Reports Server (NTRS)
Biddle, J. R.; Peterson, D. B.; Fujita, T.
1984-01-01
The engineering costs and performance of a nominal 25,000 scmd (883,000 scfd) photochemical plant to produce dihydrogen from water were studied. Two systems were considered, one based on flat-plate collector/reactors and the other on linear parabolic troughs. Engineering subsystems were specified including the collector/reactor, support hardware, field transport piping, gas compression equipment, and balance-of-plant (BOP) items. Overall plant efficiencies of 10.3 and 11.6% are estimated for the flat-plate and trough systems, respectively, based on assumed solar photochemical efficiencies of 12.9 and 14.6%. Because of the opposing effects of concentration ratio and operating temperature on efficiency, it was concluded that reactor cooling would be necessary with the trough system. Both active and passive cooling methods were considered. Capital costs and energy costs, for both concentrating and non-concentrating systems, were determined and their sensitivity to efficiency and economic parameters were analyzed. The overall plant efficiency is the single most important factor in determining the cost of the fuel.
Solar photochemical process engineering for production of fuels and chemicals
NASA Technical Reports Server (NTRS)
Biddle, J. R.; Peterson, D. B.; Fujita, T.
1985-01-01
The engineering costs and performance of a nominal 25,000 scmd (883,000 scfd) photochemical plant to produce dihydrogen from water were studied. Two systems were considered, one based on flat-plate collector/reactors and the other on linear parabolic troughs. Engineering subsystems were specified including the collector/reactor, support hardware, field transport piping, gas compression equipment, and balance-of-plant (BOP) items. Overall plant efficiencies of 10.3 and 11.6 percent are estimated for the flat-plate and trough systems, respectively, based on assumed solar photochemical efficiencies of 12.9 and 14.6 percent. Because of the opposing effects of concentration ratio and operating temperature on efficiency, it was concluded that reactor cooling would be necessary with the trough system. Both active and passive cooling methods were considered. Capital costs and energy costs, for both concentrating and non-concentrating systems, were determined and their sensitivity to efficiency and economic parameters were analyzed. The overall plant efficiency is the single most important factor in determining the cost of the fuel.
Evolutionary computing for the design search and optimization of space vehicle power subsystems
NASA Technical Reports Server (NTRS)
Kordon, Mark; Klimeck, Gerhard; Hanks, David; Hua, Hook
2004-01-01
Evolutionary computing has proven to be a straightforward and robust approach for optimizing a wide range of difficult analysis and design problems. This paper discusses the application of these techniques to an existing space vehicle power subsystem resource and performance analysis simulation in a parallel processing environment. Out preliminary results demonstrate that this approach has the potential to improve the space system trade study process by allowing engineers to statistically weight subsystem goals of mass, cost and performance then automatically size power elements based on anticipated performance of the subsystem rather than on worst-case estimates.
NASA Technical Reports Server (NTRS)
1975-01-01
A shuttle EVLSS Thermal Control System (TCS) is defined. Thirteen heat rejection subsystems, thirteen water management subsystems, nine humidity control subsystems, three pressure control schemes and five temperature control schemes are evaluated. Sixteen integrated TCS systems are studied, and an optimum system is selected based on quantitative weighting of weight, volume, cost, complexity and other factors. The selected sybsystem contains a sublimator for heat rejection, a bubble expansion tank for water management, and a slurper and rotary separator for humidity control. Design of the selected subsystem prototype hardware is presented.
NASA Astrophysics Data System (ADS)
Schwuttke, Ursula M.; Veregge, John, R.; Angelino, Robert; Childs, Cynthia L.
1990-10-01
The Monitor/Analyzer of Real-time Voyager Engineering Link (MARVEL) is described. It is the first automation tool to be used in an online mode for telemetry monitoring and analysis in mission operations. MARVEL combines standard automation techniques with embedded knowledge base systems to simultaneously provide real time monitoring of data from subsystems, near real time analysis of anomaly conditions, and both real time and non-real time user interface functions. MARVEL is currently capable of monitoring the Computer Command Subsystem (CCS), Flight Data Subsystem (FDS), and Attitude and Articulation Control Subsystem (AACS) for both Voyager spacecraft, simultaneously, on a single workstation. The goal of MARVEL is to provide cost savings and productivity enhancement in mission operations and to reduce the need for constant availability of subsystem expertise.
Proposed Reliability/Cost Model
NASA Technical Reports Server (NTRS)
Delionback, L. M.
1982-01-01
New technique estimates cost of improvement in reliability for complex system. Model format/approach is dependent upon use of subsystem cost-estimating relationships (CER's) in devising cost-effective policy. Proposed methodology should have application in broad range of engineering management decisions.
Low-cost modular array-field designs for flat-panel and concentrator photovoltaic systems
NASA Astrophysics Data System (ADS)
Post, H. N.; Carmichael, D. C.; Alexander, G.; Castle, J. A.
1982-09-01
Described are the design and development of low-cost, modular array fields for flat-panel and concentrator photovoltaic (PV) systems. The objective of the work was to reduce substantially the cost of the array-field Balance-of-System (BOS) subsystems and site-specific design costs as compared to previous PV installations. These subsystems include site preparation, foundations, support structures, electrical writing, grounding, lightning protection, electromagnetic interference considerations, and controls. To reduce these BOS and design costs, standardized modular (building-block) designs for flat-panel and concentrator array fields have been developed that are fully integrated and optimized for lowest life-cycle costs. Using drawings and specifications now available, these building-block designs can be used in multiples to install various size array fields. The developed designs are immediately applicable (1982) and reduce the array-field BOS costs to a fraction of previous costs.
Simplified power processing for ion-thruster subsystems
NASA Technical Reports Server (NTRS)
Wessel, F. J.; Hancock, D. J.
1983-01-01
Compared to chemical propulsion, ion propulsion offers distinct payload-mass increases for many future low-thrust earth-orbital and deep-space missions. Despite this advantage, the high initial cost and complexity of ion-propulsion subsystems reduce their attractiveness for most present and near-term spacecraft missions. Investigations have, therefore, been conducted with the objective to attempt to simplify the power-processing unit (PPU), which is the single most complex and expensive component in the thruster subsystem. The present investigation is concerned with a program to simplify the design of the PPU employed in a 8-cm mercury-ion-thruster subsystem. In this program a dramatic simplification in the design of the PPU could be achieved, while retaining essential thruster control and subsystem operational flexibility.
NASA Technical Reports Server (NTRS)
Bradley, F. E.
1974-01-01
Attempts made to design to costs equipment, vehicles and subsystems for various space projects are discussed. A systematic approach, based on mission requirement analysis, definition of a mission baseline design, benefit and cost analysis, and a benefit-cost analysis was proposed for implementing the cost control program.
NASA Astrophysics Data System (ADS)
Lovell, T. Alan; Schmidt, D. K.
1994-03-01
The class of hypersonic vehicle configurations with single stage-to-orbit (SSTO) capability reflect highly integrated airframe and propulsion systems. These designs are also known to exhibit a large degree of interaction between the airframe and engine dynamics. Consequently, even simplified hypersonic models are characterized by tightly coupled nonlinear equations of motion. In addition, hypersonic SSTO vehicles present a major system design challenge; the vehicle's overall mission performance is a function of its subsystem efficiencies including structural, aerodynamic, propulsive, and operational. Further, all subsystem efficiencies are interrelated, hence, independent optimization of the subsystems is not likely to lead to an optimum design. Thus, it is desired to know the effect of various subsystem efficiencies on overall mission performance. For the purposes of this analysis, mission performance will be measured in terms of the payload weight inserted into orbit. In this report, a trajectory optimization problem is formulated for a generic hypersonic lifting body for a specified orbit-injection mission. A solution method is outlined, and results are detailed for the generic vehicle, referred to as the baseline model. After evaluating the performance of the baseline model, a sensitivity study is presented to determine the effect of various subsystem efficiencies on mission performance. This consists of performing a parametric analysis of the basic design parameters, generating a matrix of configurations, and determining the mission performance of each configuration. Also, the performance loss due to constraining the total head load experienced by the vehicle is evaluated. The key results from this analysis include the formulation of the sizing problem for this vehicle class using trajectory optimization, characteristics of the optimal trajectories, and the subsystem design sensitivities.
NASA Technical Reports Server (NTRS)
Lovell, T. Alan; Schmidt, D. K.
1994-01-01
The class of hypersonic vehicle configurations with single stage-to-orbit (SSTO) capability reflect highly integrated airframe and propulsion systems. These designs are also known to exhibit a large degree of interaction between the airframe and engine dynamics. Consequently, even simplified hypersonic models are characterized by tightly coupled nonlinear equations of motion. In addition, hypersonic SSTO vehicles present a major system design challenge; the vehicle's overall mission performance is a function of its subsystem efficiencies including structural, aerodynamic, propulsive, and operational. Further, all subsystem efficiencies are interrelated, hence, independent optimization of the subsystems is not likely to lead to an optimum design. Thus, it is desired to know the effect of various subsystem efficiencies on overall mission performance. For the purposes of this analysis, mission performance will be measured in terms of the payload weight inserted into orbit. In this report, a trajectory optimization problem is formulated for a generic hypersonic lifting body for a specified orbit-injection mission. A solution method is outlined, and results are detailed for the generic vehicle, referred to as the baseline model. After evaluating the performance of the baseline model, a sensitivity study is presented to determine the effect of various subsystem efficiencies on mission performance. This consists of performing a parametric analysis of the basic design parameters, generating a matrix of configurations, and determining the mission performance of each configuration. Also, the performance loss due to constraining the total head load experienced by the vehicle is evaluated. The key results from this analysis include the formulation of the sizing problem for this vehicle class using trajectory optimization, characteristics of the optimal trajectories, and the subsystem design sensitivities.
Lightning testing at the subsystem level
NASA Technical Reports Server (NTRS)
Luteran, Frank
1991-01-01
Testing at the subsystem or black box level for lightning hardness is required if system hardness is to be assured at the system level. The often applied philosophy of lighting testing only at the system level leads to extensive end of the line design changes which result in excessive costs and time delays. In order to perform testing at the subsystem level two important factors must be defined to make the testing simulation meaningful. The first factor is the definition of the test stimulus appropriate to the subsystem level. Application of system level stimulations to the subsystem level usually leads to significant overdesign of the subsystem which is not necessary and may impair normal subsystem performance. The second factor is the availability of test equipment needed to provide the subsystem level lightning stimulation. Equipment for testing at this level should be portable or at least movable to enable efficient testing in a design laboratory environment. Large fixed test installations for system level tests are not readily available for use by the design engineers at the subsystem level and usually require special operating skills. The two factors, stimulation level and test equipment availability, must be evaluated together in order to produce a practical, workable test standard. The neglect or subordination of either factor will guarantee failure in generating the standard. It is not unusual to hear that test standards or specifications are waived because a specified stimulation level cannot be accomplished by in-house or independent test facilities. Determination of subsystem lightning simulation level requires a knowledge and evaluation of field coupling modes, peak and median levels of voltages and currents, bandwidths, and repetition rates. Practical limitations on test systems may require tradeoffs in lightning stimulation parameters in order to build practical test equipment. Peak power levels that can be generated at specified bandwidths with standard electrical components must be considered in the design and costing of the test system. Stimulation tests equipment and test methods are closely related and must be considered a test system for lightning simulation. A non-perfect specification that can be reliably and repeatedly applied at the subsystem test level is more desirable than a perfect specification that cannot be applied at all.
Mission Design and Selection of Nanosatellite Subsystems for Exploration of Lunar Water Deposits
NASA Astrophysics Data System (ADS)
Cadavid, S. C.
2018-02-01
This project presents an initiative for the development of a lunar exploration mission, looking to cover the first steps of mission design and the specifications of the mission subsystems; the Cubesat 6U configuration is taken as the low cost platform.
A 200-kW wind turbine generator conceptual design study
NASA Technical Reports Server (NTRS)
1979-01-01
A conceptual design study was conducted to define a 200 kW wind turbine power system configuration for remote applications. The goal was to attain an energy cost of 1 to 2 cents per kilowatt-hour at a 14-mph site (mean average wind velocity at an altitude of 30 ft.) The costs of the Clayton, New Mexico, Mod-OA (200-kW) were used to identify the components, subsystems, and other factors that were high in cost and thus candidates for cost reduction. Efforts devoted to developing component and subsystem concepts and ideas resulted in a machine concept that is considerably simpler, lighter in weight, and lower in cost than the present Mod-OA wind turbines. In this report are described the various innovations that contributed to the lower cost and lighter weight design as well as the method used to calculate the cost of energy.
System design of the Pioneer Venus spacecraft. Volume 7: Communication subsystem studies
NASA Technical Reports Server (NTRS)
Newlands, D. M.
1973-01-01
Communications subsystem tradeoffs were undertaken to establish a low cost and low weight design consistent with the mission requirements. Because of the weight constraint of the Thor/Delta launched configuration, minimum weight was emphasized in determining the Thor/Delta design. In contrast, because of the greatly relaxed weight constraint of the Atlas/Centaur launched configuration, minimum cost and off the shelf hardware were emphasized and the attendant weight penalities accepted. Communication subsystem hardware elements identified for study included probe and bus antennas (CM-6, CM-17), power amplifiers (CM-10), and the large probe transponder and small probe stable oscillator required for doppler tracking (CM-11, CM-16). In addition, particular hardware problems associated with the probe high temperature and high-g environment were investigated (CM-7).
QUASAR: A Method for the Quality Assessment of Software-Intensive System Architectures
2006-07-01
subsystem, the sole purpose of which is to achieve that quality. Thus, all of the requirements for a fire detec- tion and suppression subsystem are... monorail , or train tracks) along which an APM travels. 26 CMU/SEI-2006-HB-001 1. Safety Goal Claims a. Safety Factor Goals − System Is Safe...of 80 kilometers per hour.” c. Safety Subsystem Requirements − Smoke Detector Sensitivity The architecture of the automated taxi fire detection and
NASA Astrophysics Data System (ADS)
Liu, D.; Tian, F.; Lin, M.; Sivapalan, M.
2015-02-01
The complex interactions and feedbacks between humans and water are critically important issues but remain poorly understood in the newly proposed discipline of socio-hydrology (Sivapalan et al., 2012). An exploratory model with the appropriate level of simplification can be valuable for improving our understanding of the co-evolution and self-organization of socio-hydrological systems driven by interactions and feedbacks operating at different scales. In this study, a simplified conceptual socio-hydrological model based on logistic growth curves is developed for the Tarim River basin in western China and is used to illustrate the explanatory power of such a co-evolutionary model. The study area is the main stream of the Tarim River, which is divided into two modeling units. The socio-hydrological system is composed of four sub-systems, i.e., the hydrological, ecological, economic, and social sub-systems. In each modeling unit, the hydrological equation focusing on water balance is coupled to the other three evolutionary equations to represent the dynamics of the social sub-system (denoted by population), the economic sub-system (denoted by irrigated crop area ratio), and the ecological sub-system (denoted by natural vegetation cover), each of which is expressed in terms of a logistic growth curve. Four feedback loops are identified to represent the complex interactions among different sub-systems and different spatial units, of which two are inner loops occurring within each separate unit and the other two are outer loops linking the two modeling units. The feedback mechanisms are incorporated into the constitutive relations for model parameters, i.e., the colonization and mortality rates in the logistic growth curves that are jointly determined by the state variables of all sub-systems. The co-evolution of the Tarim socio-hydrological system is then analyzed with this conceptual model to gain insights into the overall system dynamics and its sensitivity to the external drivers and internal system variables. The results show a costly pendulum swing between a balanced distribution of socio-economic and natural ecologic resources among the upper and lower reaches and a highly skewed distribution towards the upper reach. This evolution is principally driven by the attitudinal changes occurring within water resources management policies that reflect the evolving community awareness of society to concerns regarding the ecology and environment.
Vibroacoustic optimization using a statistical energy analysis model
NASA Astrophysics Data System (ADS)
Culla, Antonio; D`Ambrogio, Walter; Fregolent, Annalisa; Milana, Silvia
2016-08-01
In this paper, an optimization technique for medium-high frequency dynamic problems based on Statistical Energy Analysis (SEA) method is presented. Using a SEA model, the subsystem energies are controlled by internal loss factors (ILF) and coupling loss factors (CLF), which in turn depend on the physical parameters of the subsystems. A preliminary sensitivity analysis of subsystem energy to CLF's is performed to select CLF's that are most effective on subsystem energies. Since the injected power depends not only on the external loads but on the physical parameters of the subsystems as well, it must be taken into account under certain conditions. This is accomplished in the optimization procedure, where approximate relationships between CLF's, injected power and physical parameters are derived. The approach is applied on a typical aeronautical structure: the cabin of a helicopter.
NASA Astrophysics Data System (ADS)
Xue, ShiChuan; Wu, JunJie; Xu, Ping; Yang, XueJun
2018-02-01
Quantum computing is a significant computing capability which is superior to classical computing because of its superposition feature. Distinguishing several quantum states from quantum algorithm outputs is often a vital computational task. In most cases, the quantum states tend to be non-orthogonal due to superposition; quantum mechanics has proved that perfect outcomes could not be achieved by measurements, forcing repetitive measurement. Hence, it is important to determine the optimum measuring method which requires fewer repetitions and a lower error rate. However, extending current measurement approaches mainly aiming at quantum cryptography to multi-qubit situations for quantum computing confronts challenges, such as conducting global operations which has considerable costs in the experimental realm. Therefore, in this study, we have proposed an optimum subsystem method to avoid these difficulties. We have provided an analysis of the comparison between the reduced subsystem method and the global minimum error method for two-qubit problems; the conclusions have been verified experimentally. The results showed that the subsystem method could effectively discriminate non-orthogonal two-qubit states, such as separable states, entangled pure states, and mixed states; the cost of the experimental process had been significantly reduced, in most circumstances, with acceptable error rate. We believe the optimal subsystem method is the most valuable and promising approach for multi-qubit quantum computing applications.
Design study LANDSAT follow-on mission unique communications system
NASA Technical Reports Server (NTRS)
1976-01-01
Spacecraft subsystem design, performance evaluation, and system tradeoffs are presented for the LANDSAT follow-on mission (LF/O) spacecraft to TDRSS link for the transmission of thematic mapper (TM) and multispectral scanner (MSS) data and for the LF/O spacecraft to STDN and other direct users link for the transmission of TM data. Included are requirements definition, link analysis, subsystem and hardware tradeoffs, conceptual selection, hardware definition, and identification of required new technology. Cost estimates of the recommended communication system including both recurring and non recurring costs are discussed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
This Feasibility Analysis covers a wide range of studies and evaluations. The Report is divided into five parts. Section 1 contains all material relating to the Institutional Assessment including consideration of the requirements and position of the Potomac Electric Co. as they relate to cogeneration at Georgetown in parallel with the utility (Task 1). Sections 2 through 7 contain all technical information relating to the Alternative Subsystems Analysis (Task 4). This includes the energy demand profiles upon which the evaluations were based (Task 3). It further includes the results of the Life-Cycle-Cost Analyses (Task 5) which are developed in detailmore » in the Appendix for evaluation in the Technical Report. Also included is the material relating to Incremental Savings and Optimization (Task 6) and the Conceptual Design for candidate alternate subsystems (Task 7). Section 8 contains all material relating to the Environmental Impact Assessment (Task 2). The Appendix contains supplementary material including the budget cost estimates used in the life-cycle-cost analyses, the basic assumptions upon which the life-cycle analyses were developed, and the detailed life-cycle-cost anlysis for each subsystem considered in detail.« less
NASA Technical Reports Server (NTRS)
Wynveen, R. A.; Schubert, F. H.
1972-01-01
The completion of the study is reported for the regenerative fuel cell subsystem (RFCS) as an energy storage process for use aboard the space shuttle launched modular space station (MSS). The MSS mission requirements, and RFCS are discussed, and a comparison between RFCS and a nickel cadmium battery subsystem is presented. Development costs are also discussed.
NASA Technical Reports Server (NTRS)
Keegan, W. B.
1974-01-01
In order to produce cost effective environmental test programs, the test specifications must be realistic and to be useful, they must be available early in the life of a program. This paper describes a method for achieving such specifications for subsystems by utilizing the results of a statistical analysis of data acquired at subsystem mounting locations during system level environmental tests. The paper describes the details of this statistical analysis. The resultant recommended levels are a function of the subsystems' mounting location in the spacecraft. Methods of determining this mounting 'zone' are described. Recommendations are then made as to which of the various problem areas encountered should be pursued further.
Simplified power processing for ion-thruster subsystems
NASA Technical Reports Server (NTRS)
Wessel, F. J.; Hancock, D. J.
1983-01-01
A design for a greatly simplified power-processing unit (SPPU) for the 8-cm diameter mercury-ion-thruster subsystem is discussed. This SPPU design will provide a tenfold reduction in parts count, a decrease in system mass and cost, and an increase in system reliability compared to the existing power-processing unit (PPU) used in the Hughes/NASA Lewis Research Center Ion Auxiliary Propulsion Subsystem. The simplifications achieved in this design will greatly increase the attractiveness of ion propulsion in near-term and future spacecraft propulsion applications. A description of a typical ion-thruster subsystem is given. An overview of the thruster/power-processor interface requirements is given. Simplified thruster power processing is discussed.
A duality framework for stochastic optimal control of complex systems
Malikopoulos, Andreas A.
2016-01-01
In this study, we address the problem of minimizing the long-run expected average cost of a complex system consisting of interactive subsystems. We formulate a multiobjective optimization problem of the one-stage expected costs of the subsystems and provide a duality framework to prove that the control policy yielding the Pareto optimal solution minimizes the average cost criterion of the system. We provide the conditions of existence and a geometric interpretation of the solution. For practical situations having constraints consistent with those studied here, our results imply that the Pareto control policy may be of value when we seek to derivemore » online the optimal control policy in complex systems.« less
A Status of the Advanced Space Transportation Program from Planning to Action
NASA Technical Reports Server (NTRS)
Lyles, Garry; Griner, Carolyn
1998-01-01
A Technology Plan for Enabling Commercial Space Business was presented at the 48th International Astronautical Congress in Turin, Italy. This paper presents a status of the program's accomplishments. Technology demonstrations have progressed in each of the four elements of the program; (1) Low Cost Technology, (2) Advanced Reusable Technology, (3) Space Transfer Technology and (4) Space Transportation Research. The Low Cost Technology program element is primarily focused at reducing development and acquisition costs of aerospace hardware using a "design to cost" philosophy with robust margins, adapting commercial manufacturing processes and commercial off-the-shelf hardware. The attributes of this philosophy for small payload launch are being demonstrated at the component, sub-system, and system level. The X-34 "Fastrac" engine has progressed through major component and subsystem demonstrations. A propulsion system test bed has been implemented for system-level demonstration of component and subsystem technologies; including propellant tankage and feedlines, controls, pressurization, and engine systems. Low cost turbopump designs, commercial valves and a controller are demonstrating the potential for a ten-fold reduction in engine and propulsion system costs. The Advanced Reusable Technology program element is focused on increasing life through high strength-to-weight structures and propulsion components, highly integrated propellant tanks, automated checkout and health management and increased propulsion system performance. The validation of rocket based combined cycle (RBCC) propulsion is pro,-,ressing through component and subsystem testing. RBCC propulsion has the potential to provide performance margin over an all rocket system that could result in lower gross liftoff weight, a lower propellant mass fraction or a higher payload mass fraction. The Space Transfer Technology element of the program is pursuing technology that can improve performance and dramatically reduce the propellant and structural mass of orbit transfer and deep space systems. Flight demonstration of ion propulsion is progressing towards launch. Ion propulsion is the primary propulsion for Deep Space 1; a flyby of comet West-kohoutek-lkemura and asteroid 3352 McAuliffe. Testing of critical solar-thermal propulsion subsystems have been accomplished and planning is continuing for the flight demonstration of an electrodynamic tether orbit transfer system. The forth and final element of the program, Space Transportation Research, has progressed in several areas of propulsion research. This element of the program is focused at long-term (25 years) breakthrough concepts that could bring launch costs to a factor of one hundred below today's cost or dramatically expand planetary travel and enable interstellar travel.
Code of Federal Regulations, 2010 CFR
2010-10-01
... that involve redesign of systems or subsystems. Life-cycle cost means the total cost to the Government... included, at the most appropriate time in the acquisition cycle, in solicitations and resulting contracts...
Code of Federal Regulations, 2012 CFR
2012-10-01
... that involve redesign of systems or subsystems. Life-cycle cost means the total cost to the Government... included, at the most appropriate time in the acquisition cycle, in solicitations and resulting contracts...
Code of Federal Regulations, 2014 CFR
2014-10-01
... that involve redesign of systems or subsystems. Life-cycle cost means the total cost to the Government... included, at the most appropriate time in the acquisition cycle, in solicitations and resulting contracts...
Small spacecraft power and thermal subsystems
NASA Technical Reports Server (NTRS)
Eakman, D.; Lambeck, R.; Mackowski, M.; Slifer, L., Jr.
1994-01-01
This white paper provides a general guide to the conceptual design of satellite power and thermal control subsystems with special emphasis on the unique design aspects associated with small satellites. The operating principles of these technologies are explained and performance characteristics of current and projected components are provided. A tutorial is presented on the design process for both power and thermal subsystems, with emphasis on unique issues relevant to small satellites. The ability of existing technology to meet future performance requirements is discussed. Conclusions and observations are presented that stress cost-effective, high-performance design solutions.
Improvements In A Laser-Speckle Surface-Strain Gauge
NASA Technical Reports Server (NTRS)
Lant, Christian T.
1996-01-01
Compact optical subsystem incorporates several improvements over optical subsystems of previous versions of laser-speckle surface-strain gauge: faster acquisition of data, faster response to transients, reduced size and weight, lower cost, and less complexity. Principle of operation described previously in "Laser System Measures Two-Dimensional Strain" (LEW-15046), and "Two-Dimensional Laser-Speckle Surface-Strain Gauge" (LEW-15337).
NASA Astrophysics Data System (ADS)
1980-07-01
Accomplishments are reported in the areas of: program management, system integration, the beam characterization system, receiver unit, thermal storage subsystems, master control system, plant support subsystem and engineering services. A solar facilities design integration program action items update is included. Work plan changes and cost underruns are discussed briefly. (LEW)
Calibration strategy for the COROT photometry
NASA Astrophysics Data System (ADS)
Buey, J.-T.; Auvergne, M.; Lapeyrere, V.; Boumier, P.
2004-01-01
Like Eddington, the COROT photometer will measure very small fluctutions on a large signal: the amplitudes of planetary transits and solar-like oscillations are expressed in ppm (parts per million). For such an instrument, specific calibration has to be done during the different phases of the development of the instrument and of all the subsystems. Two main things have to be taken into account: - the calibration during the study phase; - the calibration of the sub-systems and building of numerical models. The first item allows us to clearly understand all the perturbations (internal and external) and to identify their relative impacts on the expected signal (by numerical models including expected values of perturbations and sensitivity of the instrument). Methods and a schedule for the calibration process can also be introduced, in good agreement with the development plan of the instrument. The second item is more related to the measurement of the sensitivity of the instrument and all its sub-systems. As the instrument is designed to be as stable as possible, we have to mix measurements (with larger fluctuations of parameters than expected) and numerical models. Some typical reasons for that are: - there are many parameters to introduce in the measurements and results from some models (bread-board for example) may be extrapolated to the flight model; - larger fluctuations than expected are used (to measure precisely the sensitivity) and numerical models give the real value of noise with the expected fluctuations. - Characteristics of sub-systems may be measured and models used to give the sensitivity of the whole system built with them, as end-to-end measurements may be impossible (time, budget, physical limitations). Also, house-keeping measurements have to be set up on the critical parts of the sub-systems: measurements on thermal probes, power supply, pointing, etc. All these house-keeping data are used during ground calibration and during the flight, so that correct correlation between signal and house-keeping can be achieved.
NASA Technical Reports Server (NTRS)
Kuroda, Vanessa M.; Allard, Mark R.; Lewis, Brian; Lindsay, Michael
2014-01-01
September 6, 2013 through April 21, 2014 marked the mission lifecycle of the highly successful LADEE (Lunar Atmosphere and Dust Environment Explorer) mission that orbited the moon to gather detailed information about the thin lunar atmosphere. This paper will address the development, risks, and lessons learned regarding the specification, selection, and deployment of LADEE's unique Radio Frequency based communications subsystem and supporting tools. This includes the Electronic Ground Support Equipment (EGSE), test regimes, and RF dynamic link analysis environment developed to meet mission requirements for small, flexible, low cost, high performance, fast turnaround, and reusable spacecraft communication capabilities with easy and reliable application to future similar low cost small satellite missions over widely varying needs for communications and communications system complexity. LADEE communication subsystem key components, architecture, and mission performance will be reviewed toward applicability for future mission planning, design, and utilization.
NASA Astrophysics Data System (ADS)
Edwards, John L.; Beekman, Randy M.; Buchanan, David B.; Farner, Scott; Gershzohn, Gary R.; Khuzadi, Mbuyi; Mikula, D. F.; Nissen, Gerry; Peck, James; Taylor, Shaun
2007-04-01
Human space travel is inherently dangerous. Hazardous conditions will exist. Real time health monitoring of critical subsystems is essential for providing a safe abort timeline in the event of a catastrophic subsystem failure. In this paper, we discuss a practical and cost effective process for developing critical subsystem failure detection, diagnosis and response (FDDR). We also present the results of a real time health monitoring simulation of a propellant ullage pressurization subsystem failure. The health monitoring development process identifies hazards, isolates hazard causes, defines software partitioning requirements and quantifies software algorithm development. The process provides a means to establish the number and placement of sensors necessary to provide real time health monitoring. We discuss how health monitoring software tracks subsystem control commands, interprets off-nominal operational sensor data, predicts failure propagation timelines, corroborate failures predictions and formats failure protocol.
Modular thrust subsystem approaches to solar electric propulsion module design
NASA Technical Reports Server (NTRS)
Cake, J. E.; Sharp, G. R.; Oglebay, J. C.; Shaker, F. J.; Zavesky, R. J.
1976-01-01
Three approaches are presented for packaging the elements of a 30 cm ion thruster subsystem into a modular thrust subsystem. The individual modules, when integrated into a conceptual solar electric propulsion module are applicable to a multimission set of interplanetary flights with the space shuttle interim upper stage as the launch vehicle. The emphasis is on the structural and thermal integration of the components into the modular thrust subsystems. Thermal control for the power processing units is either by direct radiation through louvers in combination with heat pipes or an all heat pipe system. The propellant storage and feed system and thruster gimbal system concepts are presented. The three approaches are compared on the basis of mass, cost, testing, interfaces, simplicity, reliability, and maintainability.
Modular thrust subsystem approaches to solar electric propulsion module design
NASA Technical Reports Server (NTRS)
Cake, J. E.; Sharp, G. R.; Oglebay, J. C.; Shaker, F. J.; Zevesky, R. J.
1976-01-01
Three approaches are presented for packaging the elements of a 30 cm ion thrustor subsystem into a modular thrust subsystem. The individual modules, when integrated into a conceptual solar electric propulsion module are applicable to a multimission set of interplanetary flights with the Space Shuttle/Interim Upper Stage as the launch vehicle. The emphasis is on the structural and thermal integration of the components into the modular thrust subsystems. Thermal control for the power processing units is either by direct radiation through louvers in combination with heat pipes of an all heat pipe system. The propellant storage and feed system and thrustor gimbal system concepts are presented. The three approaches are compared on the basis of mass, cost, testing, interfaces, simplicity, reliability, and maintainability.
Aerospace Vehicle Design, Spacecraft Section. Volume 1: Project Groups 3-5
NASA Technical Reports Server (NTRS)
1989-01-01
Three groups of student engineers in an aerospace vehicle design course present their designs for a vehicle that can be used to resupply the Space Station Freedom and provide an emergency crew return to earth capability. The vehicle's requirements include a lifetime that exceeds six years, low cost, the capability for withstanding pressurization, launch, orbit, and reentry hazards, and reliability. The vehicle's subsystems are analyzed. These subsystems are structures, communication and command data systems, attitude and articulation control, life support and crew systems, power and propulsion, reentry and recovery systems, and mission management, planning, and costing.
Propulsion Options for Primary Thrust and Attitude Control of Microspacecraft
NASA Technical Reports Server (NTRS)
deGroot, W. A.
1998-01-01
Order of magnitude decreases in the size of scientific satellites and spacecraft could provide concurrent decreases in mission costs because of lower launch and fabrication costs. Although many subsystems are amenable to dramatic size reductions, miniaturization of the propulsion subsystems is not straightforward. There are a range of requirements for both primary and attitude control propulsion, dictated by mission requirements, satellite size, and power restrictions. Many of the established propulsion technologies can not currently be applied to microspacecraft. Because of this, micro-electromechanical systems (MEMS) fabrication technology is being explored as a path for miniaturization.
Narayanan, Vignesh; Jagannathan, Sarangapani
2017-06-08
This paper presents an approximate optimal distributed control scheme for a known interconnected system composed of input affine nonlinear subsystems using event-triggered state and output feedback via a novel hybrid learning scheme. First, the cost function for the overall system is redefined as the sum of cost functions of individual subsystems. A distributed optimal control policy for the interconnected system is developed using the optimal value function of each subsystem. To generate the optimal control policy, forward-in-time, neural networks are employed to reconstruct the unknown optimal value function at each subsystem online. In order to retain the advantages of event-triggered feedback for an adaptive optimal controller, a novel hybrid learning scheme is proposed to reduce the convergence time for the learning algorithm. The development is based on the observation that, in the event-triggered feedback, the sampling instants are dynamic and results in variable interevent time. To relax the requirement of entire state measurements, an extended nonlinear observer is designed at each subsystem to recover the system internal states from the measurable feedback. Using a Lyapunov-based analysis, it is demonstrated that the system states and the observer errors remain locally uniformly ultimately bounded and the control policy converges to a neighborhood of the optimal policy. Simulation results are presented to demonstrate the performance of the developed controller.
Design guide for low cost standardized payloads, volume 2
NASA Technical Reports Server (NTRS)
1972-01-01
Sixteen engineering approaches to low cost standardized payloads in spacecraft are presented. Standard earth observatory satellite, standard U.S. domestic communication satellite, planetary spacecraft subsystems, standard spacecraft, and cluster spacecraft are reviewed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Datta, Nilanjana, E-mail: n.datta@statslab.cam.ac.uk; Hsieh, Min-Hsiu, E-mail: Min-Hsiu.Hsieh@uts.edu.au; Oppenheim, Jonathan, E-mail: j.oppenheim@ucl.ac.uk
State redistribution is the protocol in which given an arbitrary tripartite quantum state, with two of the subsystems initially being with Alice and one being with Bob, the goal is for Alice to send one of her subsystems to Bob, possibly with the help of prior shared entanglement. We derive an upper bound on the second order asymptotic expansion for the quantum communication cost of achieving state redistribution with a given finite accuracy. In proving our result, we also obtain an upper bound on the quantum communication cost of this protocol in the one-shot setting, by using the protocol ofmore » coherent state merging as a primitive.« less
Cost-Effectiveness Analysis of the Automation of a Circulation System.
ERIC Educational Resources Information Center
Mosley, Isobel
A general methodology for cost effectiveness analysis was developed and applied to the Colorado State University library loan desk. The cost effectiveness of the existing semi-automated circulation system was compared with that of a fully manual one, based on the existing manual subsystem. Faculty users' time and computer operating costs were…
ERIC Educational Resources Information Center
Bowen, Brian
1974-01-01
The third installment of a Building Cost File points out the necessity of providing a framework for overall cost control during design. A cost analysis (see EA 504 571) illustrates how the use of construction elements or subsystems provide a suitable means. Other related articles are EA 503 949, 950, 951, and EA 504 578-579. (MF)
AEOSS runtime manual for system analysis on Advanced Earth-Orbital Spacecraft Systems
NASA Technical Reports Server (NTRS)
Lee, Hwa-Ping
1990-01-01
Advanced earth orbital spacecraft system (AEOSS) enables users to project the required power, weight, and cost for a generic earth-orbital spacecraft system. These variables are calculated on the component and subsystem levels, and then the system level. The included six subsystems are electric power, thermal control, structure, auxiliary propulsion, attitude control, and communication, command, and data handling. The costs are computed using statistically determined models that were derived from the flown spacecraft in the past and were categorized into classes according to their functions and structural complexity. Selected design and performance analyses for essential components and subsystems are also provided. AEOSS has the feature permitting a user to enter known values of these parameters, totally and partially, at all levels. All information is of vital importance to project managers of subsystems or a spacecraft system. AEOSS is a specially tailored software coded from the relational database program of the Acius' 4th Dimension with a Macintosh version. Because of the licensing agreements, two versions of the AEOSS documents were prepared. This version, AEOSS Runtime Manual, is permitted to be distributed with a finite number of the restrictive 4D Runtime version. It can perform all contained applications without any programming alterations.
NASA Technical Reports Server (NTRS)
Oren, J. A.
1982-01-01
The soft tube radiator subsystem is described including applicable system requirements, the design and limitations of the subsystem components, and the panel manufacturing method. The soft tube radiator subsystem is applicable to payloads requiring 1 to 12 kW of heat rejection for orbital lifetimes per mission of 30 days or less. The flexible radiator stowage volume required is about 60% and the system weight is about 40% of an equivalent heat rejection rigid panel. The cost should also be considerably less. The flexible radiator is particularly suited to shuttle orbiter sortie payloads and also whose mission lengths do not exceed the 30 day design life.
A regenerative fuel cell system for modular space station integrated electrical power.
NASA Technical Reports Server (NTRS)
Wynveen, R. A.; Schubert, F. H.
1973-01-01
A regenerative fuel cell system (RFCS) for energy storage aboard the Modular Space Station (MSS) was selected over the battery technique because of lower cost, lower launch weight, lower required solar array area, and its ability to be integrated into the station's reaction control and environmental control and life support subsystems in addition to the electrical power subsystem. The total MSS energy storage requirement was met by dividing it into four equal modular RFCSs, each made up of a fuel cell subsystem, a water electrolysis subsystem, a gas accumulator subassembly, and a water tank subassembly. The weight of each of the four RFCSs varied from 4000 to 7000 lb with the latter being a more maintainable design. The specific energy ranged between 5.6 to 9.4 watt-hr/lb.
Thermal control extravehicular life support system
NASA Technical Reports Server (NTRS)
1975-01-01
The results of a comprehensive study which defined an Extravehicular Life Support System Thermal Control System (TCS) are presented. The design of the prototype hardware and a detail summary of the prototype TCS fabrication and test effort are given. Several heat rejection subsystems, water management subsystems, humidity control subsystems, pressure control schemes and temperature control schemes were evaluated. Alternative integrated TCS systems were studied, and an optimum system was selected based on quantitative weighing of weight, volume, cost, complexity and other factors. The selected subsystem contains a sublimator for heat rejection, bubble expansion tank for water management, a slurper and rotary separator for humidity control, and a pump, a temperature control valve, a gas separator and a vehicle umbilical connector for water transport. The prototype hardware complied with program objectives.
Design guide for low cost standardized payloads, volume 1
NASA Technical Reports Server (NTRS)
1972-01-01
Concept point designs of low cost and refurbishable spacecraft, subsystems, and modules revealed payload program savings up to 50 percent. The general relationship of payload approaches to program costs; cost reductions from low cost standardized payloads; cost effective application of payload reliability, MMD, repair, and refurbishment; and implementation of standardization for future spacecraft are discussed. Shuttle interfaces and support equipment for future payloads are also considered
Shuttle cryogenic supply system optimization study. Volume 1: Management supply, sections 1 - 3
NASA Technical Reports Server (NTRS)
1973-01-01
An analysis of the cryogenic supply system for use on space shuttle vehicles was conducted. The major outputs of the analysis are: (1) evaluations of subsystem and integrated system concepts, (2) selection of representative designs, (3) parametric data and sensitivity studies, (4) evaluation of cryogenic cooling in environmental control subsystems, and (5) development of mathematical model.
Accelerated life testing of spacecraft subsystems
NASA Technical Reports Server (NTRS)
Wiksten, D.; Swanson, J.
1972-01-01
The rationale and requirements for conducting accelerated life tests on electronic subsystems of spacecraft are presented. A method for applying data on the reliability and temperature sensitivity of the parts contained in a sybsystem to the selection of accelerated life test parameters is described. Additional considerations affecting the formulation of test requirements are identified, and practical limitations of accelerated aging are described.
Design, processing and testing of LSI arrays hybrid microelectronics task
NASA Technical Reports Server (NTRS)
Himmel, R. P.; Stuhlbarg, S. M.; Salmassy, S.
1978-01-01
Those factors affecting the cost of electronic subsystems utilizing LSI microcircuits were determined and the most efficient methods for low cost packaging of LSI devices as a function of density and reliability were developed.
Solvatochromic shifts from coupled-cluster theory embedded in density functional theory
NASA Astrophysics Data System (ADS)
Höfener, Sebastian; Gomes, André Severo Pereira; Visscher, Lucas
2013-09-01
Building on the framework recently reported for determining general response properties for frozen-density embedding [S. Höfener, A. S. P. Gomes, and L. Visscher, J. Chem. Phys. 136, 044104 (2012)], 10.1063/1.3675845, in this work we report a first implementation of an embedded coupled-cluster in density-functional theory (CC-in-DFT) scheme for electronic excitations, where only the response of the active subsystem is taken into account. The formalism is applied to the calculation of coupled-cluster excitation energies of water and uracil in aqueous solution. We find that the CC-in-DFT results are in good agreement with reference calculations and experimental results. The accuracy of calculations is mainly sensitive to factors influencing the correlation treatment (basis set quality, truncation of the cluster operator) and to the embedding treatment of the ground-state (choice of density functionals). This allows for efficient approximations at the excited state calculation step without compromising the accuracy. This approximate scheme makes it possible to use a first principles approach to investigate environment effects with specific interactions at coupled-cluster level of theory at a cost comparable to that of calculations of the individual subsystems in vacuum.
Effective Schedule and Cost Management as a Product Development Lead
NASA Technical Reports Server (NTRS)
Simmons, Cynthia
2015-01-01
The presentation will be given at the 26th Annual Thermal Fluids Analysis Workshop (TFAWS 2015) hosted by the Goddard SpaceFlight Center (GSFC) Thermal Engineering Branch (Code 545). This course provides best practices, helpful tools and lessons learned for staying on plan and day-to-day management of Subsystem flight development after getting Project approval for your Subsystem schedule and budget baseline.
FLPP NGL Structural Subsystems Activity
NASA Astrophysics Data System (ADS)
Jaredson, D.; Ramusat, G.; Appel, S.; Cardone, T.; Persson, J.; Baiocco, P.; Lavelle, F.; Bouilly, Th.
2012-07-01
The ESA Future Launchers Preparatory Programme (FLPP) is the basis for new paradigms, investigating the key elements, logic and roadmaps to prepare the development of the safe, reliable and low cost next European Launch Vehicle (LV) for access to space (dubbed NGL - Next Generation LV), with an initial operational capability mid-next decade. In addition to carry cargo to conventional GTO or SSO, the European NGL has to be flexible enough to cope with new pioneering institutional missions as well as the evolving commercial payloads market. This achievement is broached studying three main areas relevant to ELVs: System concepts, Propulsion and Core Technology During the preliminary design activity, a number of design alternatives concerning NGL main structural subsystems have been investigated. Technology is one of the ways to meet the NGL challenges to either improve the performances or to reduce the cost or both. The relevant requirements allow to steer a ‘top-down’ approach for their conception and to propose the most effective technologies. Furthermore, all these technology developments represent a significant ‘bottom-up’ approach investment and concern a large range of activities. The structural subsystems portfolio of the FLPP ‘Core Technology’ activity encompasses major cutting-edge challenges for maturation of the various subsystems leading to reduce overall structural mass, increasing structural margins for robustness, metallic and composite containment of cryogenic propellants, significantly reducing fabrication and operations cost, etc. to derive performing upper and booster stages. Application of concurrent engineering methods will allow developments of performing technology demonstrators in terms of need, demonstration objective, size and cost yielding to safe, low-risk technical approaches for a future development. Potential ability of these advanced structural LV technologies to satisfy the system requirements of the NGL and their current and targeted technology readiness (i.e. TRL 6 by 2016) are being assessed to check whether a future flawless development could be performed within a given budget and schedule. The paper outlines the various technology developments for the pressurised and unpressurised structure subsystems and describes the implementation methodology, some of the current technology works performed and achieved accomplishments up to now. This is in strong connection with the “system” activity dealing with the same matter [1].
A New, Scalable and Low Cost Multi-Channel Monitoring System for Polymer Electrolyte Fuel Cells.
Calderón, Antonio José; González, Isaías; Calderón, Manuel; Segura, Francisca; Andújar, José Manuel
2016-03-09
In this work a new, scalable and low cost multi-channel monitoring system for Polymer Electrolyte Fuel Cells (PEFCs) has been designed, constructed and experimentally validated. This developed monitoring system performs non-intrusive voltage measurement of each individual cell of a PEFC stack and it is scalable, in the sense that it is capable to carry out measurements in stacks from 1 to 120 cells (from watts to kilowatts). The developed system comprises two main subsystems: hardware devoted to data acquisition (DAQ) and software devoted to real-time monitoring. The DAQ subsystem is based on the low-cost open-source platform Arduino and the real-time monitoring subsystem has been developed using the high-level graphical language NI LabVIEW. Such integration can be considered a novelty in scientific literature for PEFC monitoring systems. An original amplifying and multiplexing board has been designed to increase the Arduino input port availability. Data storage and real-time monitoring have been performed with an easy-to-use interface. Graphical and numerical visualization allows a continuous tracking of cell voltage. Scalability, flexibility, easy-to-use, versatility and low cost are the main features of the proposed approach. The system is described and experimental results are presented. These results demonstrate its suitability to monitor the voltage in a PEFC at cell level.
A New, Scalable and Low Cost Multi-Channel Monitoring System for Polymer Electrolyte Fuel Cells
Calderón, Antonio José; González, Isaías; Calderón, Manuel; Segura, Francisca; Andújar, José Manuel
2016-01-01
In this work a new, scalable and low cost multi-channel monitoring system for Polymer Electrolyte Fuel Cells (PEFCs) has been designed, constructed and experimentally validated. This developed monitoring system performs non-intrusive voltage measurement of each individual cell of a PEFC stack and it is scalable, in the sense that it is capable to carry out measurements in stacks from 1 to 120 cells (from watts to kilowatts). The developed system comprises two main subsystems: hardware devoted to data acquisition (DAQ) and software devoted to real-time monitoring. The DAQ subsystem is based on the low-cost open-source platform Arduino and the real-time monitoring subsystem has been developed using the high-level graphical language NI LabVIEW. Such integration can be considered a novelty in scientific literature for PEFC monitoring systems. An original amplifying and multiplexing board has been designed to increase the Arduino input port availability. Data storage and real-time monitoring have been performed with an easy-to-use interface. Graphical and numerical visualization allows a continuous tracking of cell voltage. Scalability, flexibility, easy-to-use, versatility and low cost are the main features of the proposed approach. The system is described and experimental results are presented. These results demonstrate its suitability to monitor the voltage in a PEFC at cell level. PMID:27005630
SEP thrust subsystem performance sensitivity analysis
NASA Technical Reports Server (NTRS)
Atkins, K. L.; Sauer, C. G., Jr.; Kerrisk, D. J.
1973-01-01
This is a two-part report on solar electric propulsion (SEP) performance sensitivity analysis. The first part describes the preliminary analysis of the SEP thrust system performance for an Encke rendezvous mission. A detailed description of thrust subsystem hardware tolerances on mission performance is included together with nominal spacecraft parameters based on these tolerances. The second part describes the method of analysis and graphical techniques used in generating the data for Part 1. Included is a description of both the trajectory program used and the additional software developed for this analysis. Part 2 also includes a comprehensive description of the use of the graphical techniques employed in this performance analysis.
Performance evaluation of G8, a high sensitivity benchtop preclinical PET/CT tomograph.
Gu, Zheng; Taschereau, Richard; Vu, Nam; Prout, David L; Silverman, Robert W; Lee, Jason; Chatziioannou, Arion F
2018-06-14
G8 is a bench top integrated PET/CT scanner dedicated to high sensitivity and high resolution imaging of mice. This work characterizes its National Electrical Manufacturers Association (NEMA) NU4-2008 performance where applicable and also provides an assessment of the basic imaging performance of the CT subsystem. Methods: The PET subsystem in G8 consists of four flat-panel type detectors arranged in a box like geometry. Each panel consists of two modules of a 26 × 26 pixelated bismuth germanate (BGO) scintillator array with individual crystals measuring 1.75 × 1.75 × 7.2 mm. The crystal arrays are coupled to multichannel photomultiplier tubes via a tapered, pixelated glass lightguide. A cone-beam CT consisting of a micro focus X-ray source and a Complementary Metal Oxide Semiconductor (CMOS) detector provides anatomical information. Sensitivity, spatial resolution, energy resolution, scatter fraction, count-rate performance and the capability of phantom and mouse imaging were evaluated for the PET subsystem. Noise, dose level, contrast and resolution were evaluated for the CT subsystem. Results: With an energy window of 350-650 keV, the peak sensitivity was measured to be 9.0% near the center of the field of view (CFOV). The crystal energy resolution ranged from 15.0% to 69.6% full width at half maximum (FWHM), with a mean of 19.3 ± 3.7%. The average detector intrinsic spatial resolution was 1.30 mm and 1.38 mm FWHM in the transverse and axial directions. The maximum likelihood expectation maximization (ML-EM) reconstructed image of a point source in air, averaged 0.81 ± 0.11 mm FWHM. The peak noise equivalent count rate (NECR) for the mouse-sized phantom was 44 kcps for a total activity of 2.9 MBq (78 µCi) and the scatter fraction was 11%. For the CT subsystem, the value of the modulation transfer function (MTF) at 10% was 2.05 cycles/mm. Conclusion: The overall performance demonstrates that the G8 can produce high quality images for molecular imaging based biomedical research. Copyright © 2018 by the Society of Nuclear Medicine and Molecular Imaging, Inc.
NASA Technical Reports Server (NTRS)
1983-01-01
Space station architectural options, habitability considerations and subsystem analyses, technology, and programmatics are reviewed. The methodology employed for conceiving and defining space station concepts is presented. As a result of this approach, architectures were conceived and along with their supporting rationale are described within this portion of the report. Habitability consideration and subsystem analyses describe the human factors associated with space station operations and includes subsections covering (1) data management, (2) communications and tracking, (3) environmental control and life support, (4) manipulator systems, (5) resupply, (6) pointing, (7) thermal management and (8) interface standardization. A consolidated matrix of subsystems technology issues as related to meeting the mission needs for a 1990's era space station is presented. Within the programmatics portion, a brief description of costing and program strategies is outlined.
NASA Technical Reports Server (NTRS)
Rosenstein, B. J.
1973-01-01
The Pioneer Venus orbiter and multiprobe missions require spacecraft maneuvers for successful accomplishment. This report presents the results of studies performed to define the propulsion subsystems required to perform those maneuvers. Primary goals were to define low mass subsystems capable of performing the required missions with a high degree of reliability for low cost. A review was performed of all applicable propellants and thruster types, as well as propellant management techniques. Based on this review, a liquid monopropellant hydrazine propulsion subsystem was selected for all multiprobe mission maneuvers, and for all orbiter mission maneuvers except orbit insertion. A pressure blowdown operating mode was selected using helium as the pressurizing gas. The forces associated with spacecraft rotations were used to control the liquid-gas interface and resulting propellant orientation within the tank.
An automated environment for multiple spacecraft engineering subsystem mission operations
NASA Technical Reports Server (NTRS)
Bahrami, K. A.; Hioe, K.; Lai, J.; Imlay, E.; Schwuttke, U.; Hsu, E.; Mikes, S.
1990-01-01
Flight operations at the Jet Propulsion Laboratory (JPL) are now performed by teams of specialists, each team dedicated to a particular spacecraft. Certain members of each team are responsible for monitoring the performances of their respective spacecraft subsystems. Ground operations, which are very complex, are manual, labor-intensive, slow, and tedious, and therefore costly and inefficient. The challenge of the new decade is to operate a large number of spacecraft simultaneously while sharing limited human and computer resources, without compromising overall reliability. The Engineering Analysis Subsystem Environment (EASE) is an architecture that enables fewer controllers to monitor and control spacecraft engineering subsystems. A prototype of EASE has been installed in the JPL Space Flight Operations Facility for on-line testing. This article describes the underlying concept, development, testing, and benefits of the EASE prototype.
Coal gasification systems engineering and analysis. Appendix A: Coal gasification catalog
NASA Technical Reports Server (NTRS)
1980-01-01
The scope of work in preparing the Coal Gasification Data Catalog included the following subtasks: (1) candidate system subsystem definition, (2) raw materials analysis, (3) market analysis for by-products, (4) alternate products analysis, (5) preliminary integrated facility requirements. Definition of candidate systems/subsystems includes the identity of and alternates for each process unit, raw material requirements, and the cost and design drivers for each process design.
Alternate concepts study extension. Volume 2: Part 4: Avionics
NASA Technical Reports Server (NTRS)
1971-01-01
A recommended baseline system is presented along with alternate avionics systems, Mark 2 avionics, booster avionics, and a cost summary. Analyses and discussions are included on the Mark 1 orbiter avionics subsystems, electrical ground support equipment, and the computer programs. Results indicate a need to define all subsystems of the baseline system, an installation study to determine the impact on the crew station, and a study on access for maintenance.
ERIC Educational Resources Information Center
Lourey, Eugene D., Comp.
The Minnesota Computer Aided Library System (MCALS) provides a basis of unification for library service program development in Minnesota for eventual linkage to the national information network. A prototype plan for communications functions is illustrated. A cost/benefits analysis was made to show the cost/effectiveness potential for MCALS. System…
Structure Design Approach and Technology Selection for Next Generation European Launchers
NASA Astrophysics Data System (ADS)
Baiocco, P.; Ramusat, G.; Kauffmann, J.; Jaredson, D.; Bouilly, Th.; Lavelle, F.; Louaas, E.
2012-07-01
In the framework of the next generation launchers activity at ESA, a top-down and a bottom-up approach has been performed for the alternative conception and promising technologies of NGL sub-assemblies and sub-systems. The top-down approach consisted in looking for system-driven design solutions and the bottom-up in the proposal of design solutions taking to substantial advantages for the system. The main investigations have been focused on structures and technologies tight to structures and interfaces. Specifications coming from a preliminary system design have been used in order to permit sub-system design with the goal to find the major advantage for the overall launch system. In this respect selection criteria have been identified and among these a specific evaluation of the payload mass over recurring cost advantage has been evaluated. The development cost, recurring cost and operational aspects have been considered as competitiveness factors for the identification of the most interesting solutions. The TRL/IRL has been assessed and a preliminary development plan has been identified. This approach is dedicated to reference NGL architectures, but alternative architectures have been investigated in order to assess their interest in terms of competitiveness factors and study of other technologies. This paper deals mainly with metallic and composite structures owing to sub-systems or sub-assemblies proposed for the NGL. The major sub-systems and structures analysed are the engine thrust frame (ETF), inter stage structures (ISS), cryogenic propellant tanks, feeding lines and attachments, pressurisation systems and fairing. The paper provides an overview of the main results of this investigation and the potential benefit it can provide.
The Malemute development program. [rocket upper stage engine design
NASA Technical Reports Server (NTRS)
Bolster, W. J.; Hoekstra, P. W.
1976-01-01
The Malemute vehicle systems are two-stage systems based on utilizing a new high performance upper stage motor with two existing military boosters. The Malmute development program is described relative to program structure, preliminary design, vehicle subsystems, and the Malemute motor. Two vehicle systems, the Nike-Malemute and Terrier-Malemute, were developed which are capable of transporting comparatively large diameter (16 in.) 200-lb payloads to altitudes of 500 and 700 km, respectively. These vehicles provide relatively low-cost transportation with two-stage reliability and launch simplicity. Flight tests of both vehicle systems revealed their performance capabilities, with the Terrier-Malemute system involving a unique Malemute motor spin sensitivity problem. It is suggested that the vehicles can be successfully flown by lowering the burnout spin rate.
Domestic wash-water reclamation using an aerospace-developed water recovery subsystem
NASA Technical Reports Server (NTRS)
Hall, J. B., Jr.
1973-01-01
A prototype aerospace distillation water recovery subsystem was tested to determine its capability to recover potable water from domestic wash water. A total of 0.0994 cu m (26.25 gallons) of domestic wash water was processed over a 7-day period at an average process rate of 0.0146 cu m per day (3.85 gallons per day). The subsystem produced water that met all United States Public Health Standards for drinking water with the exception of two standards which could not be analyzed at the required sensitivity levels. Average energy consumption for this evaluation to maintain both the recovery process and microbial control in the recovered water was approximately 3366 kilowatt-hours per cubic meter (12.74 kilowatt-hours per gallon) of water recovered. This condition represents a worst case energy consumption since no attempt was made to recover heat energy in the subsystem. An ultraviolet radiation cell installed in the effluent line of the subsystem was effective in controlling coliform micro-organisms within acceptable levels for drinking water. The subsystem recovered virtually 100 percent of the available water in the waste-water process. In addition, the subsystem removed 99.6 percent and 98.3 percent of the surfactants and phosphate, respectively, from the wash water.
Application of hybrid propulsion systems to planetary missions
NASA Technical Reports Server (NTRS)
Don, J. P.; Phen, R. L.
1971-01-01
The feasibility and application of hybrid rocket propulsion to outer-planet orbiter missions is assessed in this study and guidelines regarding future development are provided. A Jupiter Orbiter Mission was selected for evaluation because it is the earliest planetary mission which may require advanced chemical propulsion. Mission and spacecraft characteristics which affect the selection and design of propulsion subsystems are presented. Alternative propulsion subsystems, including space-storable bipropellant liquids, a solid/monopropellant vernier, and a hybrid, are compared on the basis of performance, reliability, and cost. Cost-effectiveness comparisons are made for a range of assumptions including variation in (1) the level of need for spacecraft performance (determined in part by launch vehicle injected mass capability), and (2) achievable reliability at corresponding costs. The results indicated that the hybrid and space-storable bipropellant mechanizations are competitive.
Low cost computer subsystem for the Solar Electric Propulsion Stage (SEPS)
NASA Technical Reports Server (NTRS)
1975-01-01
The Solar Electric Propulsion Stage (SEPS) subsystem which consists of the computer, custom input/output (I/O) unit, and tape recorder for mass storage of telemetry data was studied. Computer software and interface requirements were developed along with computer and I/O unit design parameters. Redundancy implementation was emphasized. Reliability analysis was performed for the complete command computer sybsystem. A SEPS fault tolerant memory breadboard was constructed and its operation demonstrated.
Spacelab output processing system architectural study
NASA Technical Reports Server (NTRS)
1977-01-01
Two different system architectures are presented. The two architectures are derived from two different data flows within the Spacelab Output Processing System. The major differences between these system architectures are in the position of the decommutation function (the first architecture performs decommutation in the latter half of the system and the second architecture performs that function in the front end of the system). In order to be examined, the system was divided into five stand-alone subsystems; Work Assembler, Mass Storage System, Output Processor, Peripheral Pool, and Resource Monitor. The work load of each subsystem was estimated independent of the specific devices to be used. The candidate devices were surveyed from a wide sampling of off-the-shelf devices. Analytical expressions were developed to quantify the projected workload in conjunction with typical devices which would adequately handle the subsystem tasks. All of the study efforts were then directed toward preparing performance and cost curves for each architecture subsystem.
1982-12-01
FIRST PRINTING RESOURCES Final - MANAGEMENT INFORMATION SYSTEM (PRMIS) COST AND FINANCIAL WORKSHOP 6. PERFORMING ORG. REPORT NUMBER 7. AUTHOR(@) I...NPPS). Cost and Financial (C&F) is a subsystem of the proposed second Printing Resources Management Information System (PRMIS II). The objectives of the
Cold-end Subsystem Testing for the Fission Power System Technology Demonstration Unit
NASA Technical Reports Server (NTRS)
Briggs, Maxwell; Gibson, Marc; Ellis, David; Sanzi, James
2013-01-01
The Fission Power System (FPS) Technology Demonstration Unit (TDU) consists of a pumped sodium-potassium (NaK) loop that provides heat to a Stirling Power Conversion Unit (PCU), which converts some of that heat into electricity and rejects the waste heat to a pumped water loop. Each of the TDU subsystems is being tested independently prior to full system testing at the NASA Glenn Research Center. The pumped NaK loop is being tested at NASA Marshall Space Flight Center; the Stirling PCU and electrical controller are being tested by Sunpower Inc.; and the pumped water loop is being tested at Glenn. This paper describes cold-end subsystem setup and testing at Glenn. The TDU cold end has been assembled in Vacuum Facility 6 (VF 6) at Glenn, the same chamber that will be used for TDU testing. Cold-end testing in VF 6 will demonstrate functionality; validated cold-end fill, drain, and emergency backup systems; and generated pump performance and system pressure drop data used to validate models. In addition, a low-cost proof-of concept radiator has been built and tested at Glenn, validating the design and demonstrating the feasibility of using low-cost metal radiators as an alternative to high-cost composite radiators in an end-to-end TDU test.
Receiver-exciter controller design
NASA Technical Reports Server (NTRS)
Jansma, P. A.
1982-01-01
A description of the general design of both the block 3 and block 4 receiver-exciter controllers for the Deep Space Network (DSN) Mark IV-A System is presented along with the design approach. The controllers are designed to enable the receiver-exciter subsystem (RCV) to be configured, calibrated, initialized and operated from a central location via high level instructions. The RECs are designed to be operated under the control of the DMC subsystem. The instructions are in the form of standard subsystem blocks (SSBs) received via the local area network (LAN). The centralized control provided by RECs and other DSCC controllers in Mark IV-A is intended to reduce DSN operations costs from the Mark III era.
Cost analysis of water recovery systems
NASA Technical Reports Server (NTRS)
Yakut, M. M.
1972-01-01
Cost and performance data from Gemini, Skylab, and other aerospace and biotechnology programs were analyzed to identify major cost elements required to establish cost estimating relationships for advanced life support subsystems for long range planning in support of earth orbital programs. Cost analysis are presented for five leading water reclamation systems; (1) RITE waste management-water system;(2) reverse osmosis system;(3) multifiltration system;(4) vapor compression system; and(5) closed air evaporation system with electrolytic pretreatment.
Optimizing Teleportation Cost in Distributed Quantum Circuits
NASA Astrophysics Data System (ADS)
Zomorodi-Moghadam, Mariam; Houshmand, Mahboobeh; Houshmand, Monireh
2018-03-01
The presented work provides a procedure for optimizing the communication cost of a distributed quantum circuit (DQC) in terms of the number of qubit teleportations. Because of technology limitations which do not allow large quantum computers to work as a single processing element, distributed quantum computation is an appropriate solution to overcome this difficulty. Previous studies have applied ad-hoc solutions to distribute a quantum system for special cases and applications. In this study, a general approach is proposed to optimize the number of teleportations for a DQC consisting of two spatially separated and long-distance quantum subsystems. To this end, different configurations of locations for executing gates whose qubits are in distinct subsystems are considered and for each of these configurations, the proposed algorithm is run to find the minimum number of required teleportations. Finally, the configuration which leads to the minimum number of teleportations is reported. The proposed method can be used as an automated procedure to find the configuration with the optimal communication cost for the DQC. This cost can be used as a basic measure of the communication cost for future works in the distributed quantum circuits.
O/S analysis of conceptual space vehicles. Part 1
NASA Technical Reports Server (NTRS)
Ebeling, Charles E.
1995-01-01
The application of recently developed computer models in determining operational capabilities and support requirements during the conceptual design of proposed space systems is discussed. The models used are the reliability and maintainability (R&M) model, the maintenance simulation model, and the operations and support (O&S) cost model. In the process of applying these models, the R&M and O&S cost models were updated. The more significant enhancements include (1) improved R&M equations for the tank subsystems, (2) the ability to allocate schedule maintenance by subsystem, (3) redefined spares calculations, (4) computing a weighted average of the working days and mission days per month, (5) the use of a position manning factor, and (6) the incorporation into the O&S model of new formulas for computing depot and organizational recurring and nonrecurring training costs and documentation costs, and depot support equipment costs. The case study used is based upon a winged, single-stage, vertical-takeoff vehicle (SSV) designed to deliver to the Space Station Freedom (SSF) a 25,000 lb payload including passengers without a crew.
NASA Technical Reports Server (NTRS)
McCurry, J. B.
1995-01-01
The purpose of the TA-2 contract was to provide advanced launch vehicle concept definition and analysis to assist NASA in the identification of future launch vehicle requirements. Contracted analysis activities included vehicle sizing and performance analysis, subsystem concept definition, propulsion subsystem definition (foreign and domestic), ground operations and facilities analysis, and life cycle cost estimation. The basic period of performance of the TA-2 contract was from May 1992 through May 1993. No-cost extensions were exercised on the contract from June 1993 through July 1995. This document is part of the final report for the TA-2 contract. The final report consists of three volumes: Volume 1 is the Executive Summary, Volume 2 is Technical Results, and Volume 3 is Program Cost Estimates. The document-at-hand, Volume 3, provides a work breakdown structure dictionary, user's guide for the parametric life cycle cost estimation tool, and final report developed by ECON, Inc., under subcontract to Lockheed Martin on TA-2 for the analysis of heavy lift launch vehicle concepts.
An efficient multilevel optimization method for engineering design
NASA Technical Reports Server (NTRS)
Vanderplaats, G. N.; Yang, Y. J.; Kim, D. S.
1988-01-01
An efficient multilevel deisgn optimization technique is presented. The proposed method is based on the concept of providing linearized information between the system level and subsystem level optimization tasks. The advantages of the method are that it does not require optimum sensitivities, nonlinear equality constraints are not needed, and the method is relatively easy to use. The disadvantage is that the coupling between subsystems is not dealt with in a precise mathematical manner.
Introducing WISDEM:An Integrated System Modeling for Wind Turbines and Plant (Presentation)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dykes, K.; Graf, P.; Scott, G.
2015-01-01
The National Wind Technology Center wind energy systems engineering initiative has developed an analysis platform to leverage its research capabilities toward integrating wind energy engineering and cost models across wind plants. This Wind-Plant Integrated System Design & Engineering Model (WISDEM) platform captures the important interactions between various subsystems to achieve a better National Wind Technology Center wind energy systems engineering initiative has developed an analysis platform to leverage its research capabilities toward integrating wind energy engineering and cost models across wind plants. This Wind-Plant Integrated System Design & Engineering Model (WISDEM) platform captures the important interactions between various subsystems tomore » achieve a better understanding of how to improve system-level performance and achieve system-level cost reductions. This work illustrates a few case studies with WISDEM that focus on the design and analysis of wind turbines and plants at different system levels.« less
Trade-offs between acquired and innate immune defenses in humans
McDade, Thomas W.; Georgiev, Alexander V.; Kuzawa, Christopher W.
2016-01-01
Immune defenses provide resistance against infectious disease that is critical to survival. But immune defenses are costly, and limited resources allocated to immunity are not available for other physiological or developmental processes. We propose a framework for explaining variation in patterns of investment in two important subsystems of anti-pathogen defense: innate (non-specific) and acquired (specific) immunity. The developmental costs of acquired immunity are high, but the costs of maintenance and activation are relatively low. Innate immunity imposes lower upfront developmental costs, but higher operating costs. Innate defenses are mobilized quickly and are effective against novel pathogens. Acquired responses are less effective against novel exposures, but more effective against secondary exposures due to immunological memory. Based on their distinct profiles of costs and effectiveness, we propose that the balance of investment in innate versus acquired immunity is variable, and that this balance is optimized in response to local ecological conditions early in development. Nutritional abundance, high pathogen exposure and low signals of extrinsic mortality risk during sensitive periods of immune development should all favor relatively higher levels of investment in acquired immunity. Undernutrition, low pathogen exposure, and high mortality risk should favor innate immune defenses. The hypothesis provides a framework for organizing prior empirical research on the impact of developmental environments on innate and acquired immunity, and suggests promising directions for future research in human ecological immunology. PMID:26739325
NASA/Air Force Cost Model: NAFCOM
NASA Technical Reports Server (NTRS)
Winn, Sharon D.; Hamcher, John W. (Technical Monitor)
2002-01-01
The NASA/Air Force Cost Model (NAFCOM) is a parametric estimating tool for space hardware. It is based on historical NASA and Air Force space projects and is primarily used in the very early phases of a development project. NAFCOM can be used at the subsystem or component levels.
LOx/LCH4: A Unifying Technology for Future Exploration
NASA Technical Reports Server (NTRS)
Banker, Brian; Ryan, Abigail
2014-01-01
OVERVIEW For every pound of payload landed on Mars, 226 pounds are required on Earth to get it there. Due to this enormous mass gear-ratio, increasing commonality between lander subsystems, such as power, propulsion, and life support, results in tremendous launch mass and cost savings. Human-Mars architectures point to an oxygen-methane economy, utilizing common commodities scavenged from the planetary atmosphere and soil via In-Situ Resource Utilization (ISRU) and common commodity tankage across sub-systems.
AEOSS design guide for system analysis on Advanced Earth-Orbital Spacecraft Systems
NASA Technical Reports Server (NTRS)
Lee, Hwa-Ping
1990-01-01
Advanced Earth Orbital Spacecraft System (AEOSS) enables users to project the requried power, weight, and cost for a generic earth-orbital spacecraft system. These variables are calculated on the component and subsystem levels, and then the system level. The included six subsystems are electric power, thermal control, structure, auxillary propulsion, attitude control, and communication, command, and data handling. The costs are computed using statistically determined models that were derived from the flown spacecraft in the past and were categorized into classes according to their functions and structural complexity. Selected design and performance analyses for essential components and subsystems are also provided. AEOSS has the feature permitting a user to enter known values of these parameters, totally and partially, at all levels. All information is of vital importance to project managers of subsystems or a spacecraft system. AEOSS is a specially tailored software coded from the relational database program of the Acius; 4th Dimension with a Macintosh version. Because of the licensing agreement, two versions of the AEOSS documents were prepared. This version AEOSS Design Guide, is for users to exploit the full capacity of the 4th Dimension. It is for a user who wants to alter or expand the program structures, the program statements, and the program procedures. The user has to possess a 4th Dimension first.
NASA Astrophysics Data System (ADS)
Ali, Anwar; Mughal, M. Rizwan; Ali, Haider; Reyneri, Leonardo
2014-03-01
Electric power supply (EPS) and attitude determination and control subsystem (ADCS) are the most essential elements of any aerospace mission. Efficient EPS and precise ADCS are the core of any spacecraft mission. So keeping in mind their importance, they have been integrated and developed on a single tile called CubePMT module. Modular power management tiles (PMTs) are already available in the market but they are less efficient, heavier in weight, consume more power and contain less number of subsystems. Commercial of the shelf (COTS) components have been used for CubePMT implementation which are low cost and easily available from the market. CubePMT is developed on the design approach of AraMiS architecture: a project developed at Politecnico di Torino that provides low cost and higher performance space missions with dimensions larger than CubeSats. The feature of AraMiS design approach is its modularity. These modules can be reused for multiple missions which helps in significant reduction of the overall budget, development and testing time. One has just to reassemble the required subsystems to achieve the targeted specific mission.
The NASA-Lewis/ERDA Solar Heating and Cooling Technology Program
NASA Technical Reports Server (NTRS)
Couch, J. P.; Bloomfield, H. S.
1975-01-01
The NASA Lewis Research Center plans to carry out a major role in the ERDA Solar Heating and Cooling Program. This role would be to create and test the enabling technology for future solar heating, cooling, and combined heating/cooling systems. The major objectives of the project are to achieve reduction in solar energy system costs, while maintaining adequate performance, reliability, life, and maintenance characteristics. The project approach is to move progressively through component, subsystem, and then system technology advancement phases in parallel with continuing manufacturing cost assessment studies. This approach will be accomplished principally by contract with industry to develop advanced components and subsystems. This advanced hardware will be tested to establish 'technology readiness' both under controlled laboratory conditions and under real sun conditions.
Study of Systems and Technology for Liquid Hydrogen Production Independent of Fossil Fuels
NASA Technical Reports Server (NTRS)
Sprafka, R. J.; Escher, W. J. D.; Foster, R. W.; Tison, R. R.; Shingleton, J.; Moore, J. S.; Baker, C. R.
1983-01-01
Based on Kennedy Space Center siting and logistics requirements and the nonfossil energy resources at the Center, a number of applicable technologies and system candidates for hydrogen production were identified and characterized. A two stage screening of these technologies in the light of specific criteria identified two leading candidates as nonfossil system approaches. Conceptual design and costing of two solar-operated, stand alone systems, one photovoltaic based on and the other involving the power tower approach reveals their technical feasibility as sited as KSC, and the potential for product cost competitiveness with conventional supply approaches in the 1990 to 1210 time period. Conventional water hydrolysis and hydrogen liquefaction subsystems are integrated with the solar subsystems.
Mass and power modeling of communication satellites
NASA Technical Reports Server (NTRS)
Price, Kent M.; Pidgeon, David; Tsao, Alex
1991-01-01
Analytic estimating relationships for the mass and power requirements for major satellite subsystems are described. The model for each subsystem is keyed to the performance drivers and system requirements that influence their selection and use. Guidelines are also given for choosing among alternative technologies which accounts for other significant variables such as cost, risk, schedule, operations, heritage, and life requirements. These models are intended for application to first order systems analyses, where resources do not warrant detailed development of a communications system scenario. Given this ground rule, the models are simplified to 'smoothed' representation of reality. Therefore, the user is cautioned that cost, schedule, and risk may be significantly impacted where interpolations are sufficiently different from existing hardware as to warrant development of new devices.
NASA Technical Reports Server (NTRS)
1974-01-01
An analysis of the design and cost tradeoff aspects of the Earth Observatory Satellite (EOS) development is presented. The design/cost factors that affect a series of mission/system level concepts are discussed. The subjects considered are as follows: (1) spacecraft subsystem cost tradeoffs, (2) ground system cost tradeoffs, and (3) program cost summary. Tables of data are provided to summarize the results of the analyses. Illustrations of the various spacecraft configurations are included.
Silicon solar photovoltaic power stations
NASA Technical Reports Server (NTRS)
Chowaniec, C. R.; Ferber, R. R.; Pittman, P. F.; Marshall, B. W.
1977-01-01
Modular design of components and arrays, cost estimates for modules and support structures, and cost/performance analysis of a central solar photovoltaic power plant are discussed. Costs of collector/reflector arrays are judged the dominant element in the total capital investment. High-concentration solar tracking arrays are recommended as the most economic means for producing solar photovoltaic energy when solar cells costs are high ($500 per kW generated). Capital costs for power conditioning subsystem components are itemized and system busbar energy costs are discussed at length.
Space Tug Docking Study. Volume 5: Cost Analysis
NASA Technical Reports Server (NTRS)
1976-01-01
The cost methodology, summary cost data, resulting cost estimates by Work Breakdown Structure (WBS), technical characteristics data, program funding schedules and the WBS for the costing are discussed. Cost estimates for two tasks of the study are reported. The first, developed cost estimates for design, development, test and evaluation (DDT&E) and theoretical first unit (TFU) at the component level (Level 7) for all items reported in the data base. Task B developed total subsystem DDT&E costs and funding schedules for the three candidate Rendezvous and Docking Systems: manual, autonomous, and hybrid.
Some Options for a Minimum Solar Probe Mission
NASA Technical Reports Server (NTRS)
Randolph, J. E.; Tsurutani, B. T.; Turner, P. R.; Miyake, R. M.; Ayon, J. A.
1996-01-01
Smaller and lower cost options of NASA's Solar Probe mission have recently been studied. The difference between these options and the results of earlier studies is dramatic. The motivation for low cost has encouraged the JPL design team to accomodate a smaller scientific payload using innovative multi-functional subsystems.
48 CFR 252.242-7006 - Accounting system administration.
Code of Federal Regulations, 2011 CFR
2011-10-01
... complied with; (ii) The accounting system and cost data are reliable; (iii) Risk of misallocations and... management decisions, and may include subsystems for specific areas such as indirect and other direct costs... rely upon information produced by the system that is needed for management purposes. (b) General. The...
48 CFR 252.242-7006 - Accounting system administration.
Code of Federal Regulations, 2013 CFR
2013-10-01
... complied with; (ii) The accounting system and cost data are reliable; (iii) Risk of misallocations and... management decisions, and may include subsystems for specific areas such as indirect and other direct costs... rely upon information produced by the system that is needed for management purposes. (b) General. The...
48 CFR 252.242-7006 - Accounting system administration.
Code of Federal Regulations, 2012 CFR
2012-10-01
... complied with; (ii) The accounting system and cost data are reliable; (iii) Risk of misallocations and... management decisions, and may include subsystems for specific areas such as indirect and other direct costs... rely upon information produced by the system that is needed for management purposes. (b) General. The...
48 CFR 252.242-7006 - Accounting system administration.
Code of Federal Regulations, 2014 CFR
2014-10-01
... complied with; (ii) The accounting system and cost data are reliable; (iii) Risk of misallocations and... management decisions, and may include subsystems for specific areas such as indirect and other direct costs... rely upon information produced by the system that is needed for management purposes. (b) General. The...
Automated distribution system management for multichannel space power systems
NASA Technical Reports Server (NTRS)
Fleck, G. W.; Decker, D. K.; Graves, J.
1983-01-01
A NASA sponsored study of space power distribution system technology is in progress to develop an autonomously managed power system (AMPS) for large space power platforms. The multichannel, multikilowatt, utility-type power subsystem proposed presents new survivability requirements and increased subsystem complexity. The computer controls under development for the power management system must optimize the power subsystem performance and minimize the life cycle cost of the platform. A distribution system management philosophy has been formulated which incorporates these constraints. Its implementation using a TI9900 microprocessor and FORTH as the programming language is presented. The approach offers a novel solution to the perplexing problem of determining the optimal combination of loads which should be connected to each power channel for a versatile electrical distribution concept.
Airborne Advanced Reconfigurable Computer System (ARCS)
NASA Technical Reports Server (NTRS)
Bjurman, B. E.; Jenkins, G. M.; Masreliez, C. J.; Mcclellan, K. L.; Templeman, J. E.
1976-01-01
A digital computer subsystem fault-tolerant concept was defined, and the potential benefits and costs of such a subsystem were assessed when used as the central element of a new transport's flight control system. The derived advanced reconfigurable computer system (ARCS) is a triple-redundant computer subsystem that automatically reconfigures, under multiple fault conditions, from triplex to duplex to simplex operation, with redundancy recovery if the fault condition is transient. The study included criteria development covering factors at the aircraft's operation level that would influence the design of a fault-tolerant system for commercial airline use. A new reliability analysis tool was developed for evaluating redundant, fault-tolerant system availability and survivability; and a stringent digital system software design methodology was used to achieve design/implementation visibility.
NASA Technical Reports Server (NTRS)
1985-01-01
An overview of the second quarter 1985 development of the X-ray satellite project is presented. It is shown that the project is proceeding according to plan and that the projected launch date of September 9, 1987 is on schedule. An overview of the work completed and underway on the systems, subsystems, payload, assembly, ground equipment and interfaces is presented. Problem areas shown include cost increases in the area of focal instrumentation, the star sensor light scattering requirements, and postponements in the data transmission subsystems.
Acquisition-Management Program
NASA Technical Reports Server (NTRS)
Avery, Don E.; Vann, A. Vernon; Jones, Richard H.; Rew, William E.
1987-01-01
NASA Acquisition Management Subsystem (AMS) program integrated NASA-wide standard automated-procurement-system program developed in 1985. Designed to provide each NASA installation with procurement data-base concept with on-line terminals for managing, tracking, reporting, and controlling contractual actions and associated procurement data. Subsystem provides control, status, and reporting for various procurement areas. Purpose of standardization is to decrease costs of procurement and operation of automatic data processing; increases procurement productivity; furnishes accurate, on-line management information and improves customer support. Written in the ADABAS NATURAL.
Design optimization for cost and quality: The robust design approach
NASA Technical Reports Server (NTRS)
Unal, Resit
1990-01-01
Designing reliable, low cost, and operable space systems has become the key to future space operations. Designing high quality space systems at low cost is an economic and technological challenge to the designer. A systematic and efficient way to meet this challenge is a new method of design optimization for performance, quality, and cost, called Robust Design. Robust Design is an approach for design optimization. It consists of: making system performance insensitive to material and subsystem variation, thus allowing the use of less costly materials and components; making designs less sensitive to the variations in the operating environment, thus improving reliability and reducing operating costs; and using a new structured development process so that engineering time is used most productively. The objective in Robust Design is to select the best combination of controllable design parameters so that the system is most robust to uncontrollable noise factors. The robust design methodology uses a mathematical tool called an orthogonal array, from design of experiments theory, to study a large number of decision variables with a significantly small number of experiments. Robust design also uses a statistical measure of performance, called a signal-to-noise ratio, from electrical control theory, to evaluate the level of performance and the effect of noise factors. The purpose is to investigate the Robust Design methodology for improving quality and cost, demonstrate its application by the use of an example, and suggest its use as an integral part of space system design process.
MHD Advanced Power Train Phase I, Final Report, Volume 7
DOE Office of Scientific and Technical Information (OSTI.GOV)
A. R. Jones
This appendix provides additional data in support of the MHD/Steam Power Plant Analyses reported in report Volume 5. The data is in the form of 3PA/SUMARY computer code printouts. The order of presentation in all four cases is as follows: (1) Overall Performance; (2) Component/Subsystem Information; (3) Plant Cost Accounts Summary; and (4) Plant Costing Details and Cost of Electricity.
Logistics of a Lunar Based Solar Power Satellite Scenario
NASA Technical Reports Server (NTRS)
Melissopoulos, Stefanos
1995-01-01
A logistics system comprised of two orbital stations for the support of a 500 GW space power satellite scenario in a geostationary orbit was investigated in this study. A subsystem mass model, a mass flow model and a life cycle cost model were developed. The results regarding logistics cost and burden rates show that the transportation cost contributed the most (96%) to the overall cost of the scenario. The orbital stations at a geostationary and at a lunar orbit contributed 4 % to that cost.
Development and in-flight performance of the Mariner 9 spacecraft propulsion system
NASA Technical Reports Server (NTRS)
Evans, D. D.; Cannova, R. D.; Cork, M. J.
1972-01-01
On November 14, 1971, Mariner 9 was decelerated into orbit about Mars by a 1334-newton (300-lbf) liquid bipropellant propulsion system. The development and in-flight performance are described and summarized of this pressure-fed, nitrogen tetroxide/monomethyl hydrazine bipropellant system. The design of all Mariner propulsion subsystems has been predicated upon the premise that simplicity of approach, coupled with thorough qualification and margin-limits testing, is the key to cost-effective reliability. The qualification test program and analytical modeling of the Mariner 9 subsystem are discussed. Since the propulsion subsystem is modular in nature, it was completely checked, serviced, and tested independent of the spacecraft. Proper prediction of in-flight performance required the development of three significant modeling tools to predict and account for nitrogen saturation of the propellant during the six-month coast period and to predict and statistically analyze in-flight data. The flight performance of the subsystem was excellent, as were the performance prediction correlations. These correlations are presented.
Petite Amateur Navy Satellite (PANSAT)
NASA Technical Reports Server (NTRS)
1989-01-01
The subsystem and structural design of the Naval Post Graduate School's Petite Amateur Navy Satellite (PANSAT) is described. The objectives of PANSAT are: (1) to provide an ideal educational tool for officer students; (2) to provide digital store-and-forward communications, or packet radio, for the amateur radio community; and (3) to provide a low-cost space-based platform for small experiments. PANSAT will be launched from the Shuttle at a nominal altitude of 200 nmi. and an inclination of at least 37 deg. Since there is no attitude control, eight dipole whip antennas will be used to provide isotropic ground coverage for communications. FM digital communications will be used with up-link and down-link on a single frequency in the amateur band of 144 to 146 MHz or 437 to 438 MHz. The satellite's communications subsystem, data processor and sequencer, power subsystem, structure subsystem, and experiment payload are described. The major experiment being considered will test the on-orbit annealing of radiation damaged solar cells.
A synchronized multipoint vision-based system for displacement measurement of civil infrastructures.
Ho, Hoai-Nam; Lee, Jong-Han; Park, Young-Soo; Lee, Jong-Jae
2012-01-01
This study presents an advanced multipoint vision-based system for dynamic displacement measurement of civil infrastructures. The proposed system consists of commercial camcorders, frame grabbers, low-cost PCs, and a wireless LAN access point. The images of target panels attached to a structure are captured by camcorders and streamed into the PC via frame grabbers. Then the displacements of targets are calculated using image processing techniques with premeasured calibration parameters. This system can simultaneously support two camcorders at the subsystem level for dynamic real-time displacement measurement. The data of each subsystem including system time are wirelessly transferred from the subsystem PCs to master PC and vice versa. Furthermore, synchronization process is implemented to ensure the time synchronization between the master PC and subsystem PCs. Several shaking table tests were conducted to verify the effectiveness of the proposed system, and the results showed very good agreement with those from a conventional sensor with an error of less than 2%.
A Synchronized Multipoint Vision-Based System for Displacement Measurement of Civil Infrastructures
Ho, Hoai-Nam; Lee, Jong-Han; Park, Young-Soo; Lee, Jong-Jae
2012-01-01
This study presents an advanced multipoint vision-based system for dynamic displacement measurement of civil infrastructures. The proposed system consists of commercial camcorders, frame grabbers, low-cost PCs, and a wireless LAN access point. The images of target panels attached to a structure are captured by camcorders and streamed into the PC via frame grabbers. Then the displacements of targets are calculated using image processing techniques with premeasured calibration parameters. This system can simultaneously support two camcorders at the subsystem level for dynamic real-time displacement measurement. The data of each subsystem including system time are wirelessly transferred from the subsystem PCs to master PC and vice versa. Furthermore, synchronization process is implemented to ensure the time synchronization between the master PC and subsystem PCs. Several shaking table tests were conducted to verify the effectiveness of the proposed system, and the results showed very good agreement with those from a conventional sensor with an error of less than 2%. PMID:23028250
Conceptual design of free-piston Stirling conversion system for solar power units
NASA Astrophysics Data System (ADS)
Loktionov, Iu. V.
A conversion system has been conceptually designed for solar power units of the dish-Stirling type. The main design objectives were to demonstrate the possibility of attaining such performance characteristics as low manufacturing and life cycle costs, high reliability, long life, high efficiency, power output stability, self-balance, automatic (or self-) start-up, and easy maintenance. The system design includes a heat transfer and utilization subsystem with a solar receiver, a free-piston engine, an electric power generation subsystem, and a control subsystem. The working fluid is helium. The structural material is stainless steel for hot elements, aluminum alloys and plastics for others. The electric generation subunit can be fabricated in three options: with an induction linear alternator, with a permanent magnet linear alternator, and with a serial rotated induction generator and a hydraulic drive subsystem. The heat transfer system is based on heat pipes or the reflux boiler principle. Several models of heat transfer units using a liquid metal (Na or Na-K) have been created and demonstrated.
Improving the Reliability of Technological Subsystems Equipment for Steam Turbine Unit in Operation
NASA Astrophysics Data System (ADS)
Brodov, Yu. M.; Murmansky, B. E.; Aronson, R. T.
2017-11-01
The authors’ conception is presented of an integrated approach to reliability improving of the steam turbine unit (STU) state along with its implementation examples for the various STU technological subsystems. Basing on the statistical analysis of damage to turbine individual parts and components, on the development and application of modern methods and technologies of repair and on operational monitoring techniques, the critical components and elements of equipment are identified and priorities are proposed for improving the reliability of STU equipment in operation. The research results are presented of the analysis of malfunctions for various STU technological subsystems equipment operating as part of power units and at cross-linked thermal power plants and resulting in turbine unit shutdown (failure). Proposals are formulated and justified for adjustment of maintenance and repair for turbine components and parts, for condenser unit equipment, for regeneration subsystem and oil supply system that permit to increase the operational reliability, to reduce the cost of STU maintenance and repair and to optimize the timing and amount of repairs.
NASA Technical Reports Server (NTRS)
Allen, Cheryl L.
1991-01-01
Enhanced engineering tools can be obtained through the integration of expert system methodologies and existing design software. The application of these methodologies to the spacecraft design and cost model (SDCM) software provides an improved technique for the selection of hardware for unmanned spacecraft subsystem design. The knowledge engineering system (KES) expert system development tool was used to implement a smarter equipment section algorithm than that which is currently achievable through the use of a standard data base system. The guidance, navigation, and control subsystems of the SDCM software was chosen as the initial subsystem for implementation. The portions of the SDCM code which compute the selection criteria and constraints remain intact, and the expert system equipment selection algorithm is embedded within this existing code. The architecture of this new methodology is described and its implementation is reported. The project background and a brief overview of the expert system is described, and once the details of the design are characterized, an example of its implementation is demonstrated.
Appendices for the Space Applications program, 1974
NASA Technical Reports Server (NTRS)
1974-01-01
To achieve truly low cost system design with direct evolution for inorbit shuttle resupply, a modular building block approach has been adopted. The heart of the modular building block concept lies in the ability to use a common set of nonoptimized subsystems in such a way that a wide variety of missions can be flown with no detrimental impact on performance. By standardizing the mechanical configurations and electrical interfaces of the subsystem modules, and by designing each of them to be structurally and thermally independent entities, it is possible to cluster these building blocks or modules about an instrument system so as to adequately perform the mission without the need for subsystem redevelopments for each mission. This system concept offers the following capabilities: (1) the ability to launch and orbit the observatory by either the Delta, the Titan, or the space shuttle. (2) the ability to completely reconfigure the spacecraft subsystems for different launch vehicles, and (3) the ability to perform in-orbit resupply and/or emergency retrieval of the observatory.
Human Exploration Spacecraft Testbed for Integration and Advancement (HESTIA)
NASA Technical Reports Server (NTRS)
Banker, Brian F.; Robinson, Travis
2016-01-01
The proposed paper will cover ongoing effort named HESTIA (Human Exploration Spacecraft Testbed for Integration and Advancement), led at the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) to promote a cross-subsystem approach to developing Mars-enabling technologies with the ultimate goal of integrated system optimization. HESTIA also aims to develop the infrastructure required to rapidly test these highly integrated systems at a low cost. The initial focus is on the common fluids architecture required to enable human exploration of mars, specifically between life support and in-situ resource utilization (ISRU) subsystems. An overview of the advancements in both integrated technologies, in infrastructure, in simulation, and in modeling capabilities will be presented, as well as the results and findings of integrated testing,. Due to the enormous mass gear-ratio required for human exploration beyond low-earth orbit, (for every 1 kg of payload landed on Mars, 226 kg will be required on Earth), minimization of surface hardware and commodities is paramount. Hardware requirements can be minimized by reduction of equipment performing similar functions though for different subsystems. If hardware could be developed which meets the requirements of both life support and ISRU it could result in the reduction of primary hardware and/or reduction in spares. Minimization of commodities to the surface of mars can be achieved through the creation of higher efficiency systems producing little to no undesired waste, such as a closed-loop life support subsystem. Where complete efficiency is impossible or impractical, makeup commodities could be manufactured via ISRU. Although, utilization of ISRU products (oxygen and water) for crew consumption holds great promise of reducing demands on life support hardware, there exist concerns as to the purity and transportation of commodities. To date, ISRU has been focused on production rates and purities for propulsion needs. The meshing of requirements between all potential users, producers, and cleaners of oxygen and water is crucial to guiding the development of technologies which will be used to perform these functions. Various new capabilities are being developed as part of HESTIA, which will enable the integrated testing of these technologies. This includes the upgrading of a 20' diameter habitat chamber to eventually support long duration (90+ day) human-in-the-loop testing of advanced life support systems. Additionally, a 20' diameter vacuum chamber is being modified to create Mars atmospheric pressures and compositions. This chamber, designated the Mars Environment Chamber (MEC), will eventually be upgraded to include a dusty environment and thermal shroud to simulate conditions on the surface of Mars. In view that individual technologies will be in geographically diverse locations across NASA facilities and elsewhere in the world, schedule and funding constraints will likely limit the frequency of physical integration. When this is the case, absent subsystems can be either digitally or physically simulated. Using the Integrated Power Avionics and Software (iPAS) environment, HESTIA is able to bring together data from various subsystems in simulated surroundings, insert faults, errors, time delays, etc., and feed data into computer models or physical systems capable of reproducing the output of the absent subsystems for the consumption of a local subsystems. Although imperfect, this capability provides opportunities to test subsystem integration and interactions at a fraction of the cost. When a subsystem technology is too immature for integrated testing, models can be produced using the General-Use Nodal Network Solver (GUNNS) capability to simulate the overall system performance. In doing so, even technologies not yet on the drawing board can be integrated and overall system performance estimated. Through the integrated development of technologies, as well as of the infrastructure to rapidly and at a low cost, model, simulate, and test subsystem technologies early in their development, HESTIA is pioneering a new way of developing the future of human space exploration.
NASA Technical Reports Server (NTRS)
Deacetis, Louis A.
1991-01-01
The need to reduce the costs of Space Station Freedom has resulted in a major redesign and downsizing of the Station in general, and its Communications and Tracking (C&T) components in particular. Earlier models and simulations of the C&T Space-to-Ground Subsystem (SGS) in particular are no longer valid. There thus exists a general need for updated, high fidelity simulations of C&T subsystems. This project explored simulation techniques and methods that might be used in developing new simulations of C&T subsystems, including the SGS. Three requirements were placed on the simulations to be developed: (1) they run on IBM PC/XT/AT compatible computers; (2) they be written in Ada as much as possible; and (3) since control and monitoring of the C&T subsystems will involve communication via a MIL-STD-1553B serial bus, that the possibility of commanding the simulator and monitoring its sensors via that bus be included in the design of the simulator. The result of the project is a prototype of a simulation of the Assembly/Contingency Transponder of the SGS, written in Ada, which can be controlled from another PC via a MIL-STD-1553B bus.
Costs and description of a solar-energy system--Austin, Texas
NASA Technical Reports Server (NTRS)
1981-01-01
Heating and cooling system uses Fresnel lens concentrating collectors. Major system components are 36 collectors, 1,500 gallon thermal storage tank, absorption cooler, cooling tower, heating coil, pumps, heat exchanger, and backup heating and air conditioning. Final report includes detailed breakdown of component and installation costs for seven project subsystems.
Entanglement negativity and sudden death in the toric code at finite temperature
NASA Astrophysics Data System (ADS)
Hart, O.; Castelnovo, C.
2018-04-01
We study the fate of quantum correlations at finite temperature in the two-dimensional toric code using the logarithmic entanglement negativity. We are able to obtain exact results that give us insight into how thermal excitations affect quantum entanglement. The toric code has two types of elementary excitations (defects) costing different energies. We show that an O (1 ) density of the lower energy defect is required to degrade the zero-temperature entanglement between two subsystems in contact with one another. However, one type of excitation alone is not sufficient to kill all quantum correlations, and an O (1 ) density of the higher energy defect is required to cause the so-called sudden death of the negativity. Interestingly, if the energy cost of one of the excitations is taken to infinity, quantum correlations survive up to arbitrarily high temperatures, a feature that is likely shared with other quantum spin liquids and frustrated systems in general, when projected down to their low-energy states. We demonstrate this behavior both for small subsystems, where we can prove that the negativity is a necessary and sufficient condition for separability, as well as for extended subsystems, where it is only a necessary condition. We further observe that the negativity per boundary degree of freedom at a given temperature increases (parametrically) with the size of the boundary, and that quantum correlations between subsystems with extended boundaries are more robust to thermal fluctuations.
Solar power satellite cost estimate
NASA Technical Reports Server (NTRS)
Harron, R. J.; Wadle, R. C.
1981-01-01
The solar power configuration costed is the 5 GW silicon solar cell reference system. The subsystems identified by work breakdown structure elements to the lowest level for which cost information was generated. This breakdown divides into five sections: the satellite, construction, transportation, the ground receiving station and maintenance. For each work breakdown structure element, a definition, design description and cost estimate were included. An effort was made to include for each element a reference that more thoroughly describes the element and the method of costing used. All costs are in 1977 dollars.
Development of components for an S-band phased array antenna subsystem
NASA Technical Reports Server (NTRS)
1975-01-01
The system requirements, module test data, and S-band phased array subsystem test data are discussed. Of the two approaches to achieving antenna gain (mechanically steered reflector or electronically steered phased array), the phased array approach offers the greatest simplicity and lowest cost (size, weight, power, and dollars) for this medium gain. A competitive system design is described as well as hardware evaluation which will lead to timely availability of this technology for implementing such a system. The objectives of the study were: to fabricate and test six engineering model transmit/receive microelectronics modules; to design, fabricate, and test one dc and logic multilayer manifold; and to integrate and test an S-band phased array antenna subsystem composed of antenna elements, seven T/R modules, RF manifolds and dc manifold.
Flexible Approximation Model Approach for Bi-Level Integrated System Synthesis
NASA Technical Reports Server (NTRS)
Sobieszczanski-Sobieski, Jaroslaw; Kim, Hongman; Ragon, Scott; Soremekun, Grant; Malone, Brett
2004-01-01
Bi-Level Integrated System Synthesis (BLISS) is an approach that allows design problems to be naturally decomposed into a set of subsystem optimizations and a single system optimization. In the BLISS approach, approximate mathematical models are used to transfer information from the subsystem optimizations to the system optimization. Accurate approximation models are therefore critical to the success of the BLISS procedure. In this paper, new capabilities that are being developed to generate accurate approximation models for BLISS procedure will be described. The benefits of using flexible approximation models such as Kriging will be demonstrated in terms of convergence characteristics and computational cost. An approach of dealing with cases where subsystem optimization cannot find a feasible design will be investigated by using the new flexible approximation models for the violated local constraints.
Life Support System Technologies for NASA Exploration Missions
NASA Technical Reports Server (NTRS)
Ewert, Michael K.
2007-01-01
The Lunar Mars Life Support Test series successfully demonstrated integration and operation of advanced technologies for closed-loop life support systems, including physicochemical and biological subsystems. Increased closure was obtained when targeted technologies, such as brine dewatering subsystems, were added to further process life support system byproducts to recover resources. Physicochemical and biological systems can be integrated satisfactorily to achieve desired levels of closure. Imbalances between system components, such as differences in metabolic quotients between human crews and plants, must be addressed. Each subsystem or component that is added to increase closure will likely have added costs, ranging from initial launch mass, power, thermal, crew time, byproducts, etc., that must be factored into break even analysis. Achieving life support system closure while maintaining control of total mass and system complexity will be a challenge.
AIAA spacecraft GN&C interface standards initiative: Overview
NASA Technical Reports Server (NTRS)
Challoner, A. Dorian
1995-01-01
The American Institute of Aeronautics and Astronautics (AIAA) has undertaken an important standards initiative in the area of spacecraft guidance, navigation, and control (GN&C) subsystem interfaces. The objective of this effort is to establish standards that will promote interchangeability of major GN&C components, thus enabling substantially lower spacecraft development costs. Although initiated by developers of conventional spacecraft GN&C, it is anticipated that interface standards will also be of value in reducing the development costs of micro-engineered spacecraft. The standardization targets are specifically limited to interfaces only, including information (i.e. data and signal), power, mechanical, thermal, and environmental interfaces between various GN&C components and between GN&C subsystems and other subsystems. The current emphasis is on information interfaces between various hardware elements (e.g., between star trackers and flight computers). The poster presentation will briefly describe the program, including the mechanics and schedule, and will publicize the technical products as they exist at the time of the conference. In particular, the rationale for the adoption of the AS1773 fiber-optic serial data bus and the status of data interface standards at the application layer will be presented.
NASA Technical Reports Server (NTRS)
Ebeling, Charles; Beasley, Kenneth D.
1992-01-01
The first year of research to provide NASA support in predicting operational and support parameters and costs of proposed space systems is reported. Some of the specific research objectives were (1) to develop a methodology for deriving reliability and maintainability parameters and, based upon their estimates, determine the operational capability and support costs, and (2) to identify data sources and establish an initial data base to implement the methodology. Implementation of the methodology is accomplished through the development of a comprehensive computer model. While the model appears to work reasonably well when applied to aircraft systems, it was not accurate when used for space systems. The model is dynamic and should be updated as new data become available. It is particularly important to integrate the current aircraft data base with data obtained from the Space Shuttle and other space systems since subsystems unique to a space vehicle require data not available from aircraft. This research only addressed the major subsystems on the vehicle.
Spacecraft design project multipurpose satellite bus MPS
NASA Technical Reports Server (NTRS)
Kellman, Lyle; Riley, John; Szostak, Michael; Watkins, Joseph; Willhelm, Joseph; Yale, Gary
1990-01-01
The thrust of this project was to design not a single spacecraft, but to design a multimission bus capable of supporting several current payloads and unnamed, unspecified future payloads. Spiraling costs of spacecraft and shrinking defense budgets necessitated a fresh look at the feasibility of a multimission spacecraft bus. The design team chose two very diverse and different payloads, and along with them two vastly different orbits, to show that multimission spacecraft buses are an area where indeed more research and effort needs to be made. Tradeoffs, of course, were made throughout the design, but optimization of subsystem components limited weight and volume penalties, performance degradation, and reliability concerns. Simplicity was chosen over more complex, sophisticated and usually more efficient designs. Cost of individual subsystem components was not a primary concern in the design phase, but every effort was made to chose flight tested and flight proven hardware. Significant cost savings could be realized if a standard spacecraft bus was indeed designed and purchased in finite quantities.
NASA Astrophysics Data System (ADS)
Szydzik, C.; Gavela, A. F.; Roccisano, J.; Herranz de Andrés, S.; Mitchell, A.; Lechuga, L. M.
2016-12-01
We present recent results on the realisation and demonstration of an integrated optofluidic lab-on-a-chip measurement system. The system consists of an integrated on-chip automated microfluidic fluid handling subsystem, coupled with bimodal nano-interferometer waveguide technology, and is applied in the context of detection of antibiotics in seawater. The bimodal waveguide (BMWG) is a highly sensitive label-free biosensor. Integration of complex microfluidic systems with bimodal waveguide technology enables on-chip sample handling and fluid processing capabilities and allows for significant automation of experimental processes. The on-chip fluid-handling subsystem is realised through the integration of pneumatically actuated elastomer pumps and valves, enabling high temporal resolution sample and reagent delivery and facilitating multiplexed detection processes.
Electric Propulsion Upper-Stage for Launch Vehicle Capability Enhancement
NASA Technical Reports Server (NTRS)
Kemp, Gregory E.; Dankanich, John W.; Woodcock, Gordon R.; Wingo, Dennis R.
2007-01-01
The NASA In-Space Propulsion Technology Project Office initiated a preliminary study to evaluate the performance benefits of a solar electric propulsion (SEP) upper-stage with existing and near-term small launch vehicles. The analysis included circular and elliptical Low Earth Orbit (LEO) to Geosynchronous Earth Orbit (GEO) transfers, and LEO to Low Lunar Orbit (LLO) applications. SEP subsystem options included state-of-the-art and near-term solar arrays and electric thrusters. In-depth evaluations of the Aerojet BPT-4000 Hall thruster and NEXT gridded ion engine were conducted to compare performance, cost and revenue potential. Preliminary results indicate that Hall thruster technology is favored for low-cost, low power SEP stages, while gridded-ion engines are favored for higher power SEP systems unfettered by transfer time constraints. A low-cost point design is presented that details one possible stage configuration and outlines system limitations, in particular fairing volume constraints. The results demonstrate mission enhancements to large and medium class launch vehicles, and mission enabling performance when SEP system upper stages are mounted to low-cost launchers such as the Minotaur and Falcon 1. Study results indicate the potential use of SEP upper stages to double GEO payload mass capability and to possibly enable launch on demand capability for GEO assets. Transition from government to commercial applications, with associated cost/benefit analysis, has also been assessed. The sensitivity of system performance to specific impulse, array power, thruster size, and component costs are also discussed.
Dynamics and control of the ERK signaling pathway: Sensitivity, bistability, and oscillations.
Arkun, Yaman; Yasemi, Mohammadreza
2018-01-01
Cell signaling is the process by which extracellular information is transmitted into the cell to perform useful biological functions. The ERK (extracellular-signal-regulated kinase) signaling controls several cellular processes such as cell growth, proliferation, differentiation and apoptosis. The ERK signaling pathway considered in this work starts with an extracellular stimulus and ends with activated (double phosphorylated) ERK which gets translocated into the nucleus. We model and analyze this complex pathway by decomposing it into three functional subsystems. The first subsystem spans the initial part of the pathway from the extracellular growth factor to the formation of the SOS complex, ShC-Grb2-SOS. The second subsystem includes the activation of Ras which is mediated by the SOS complex. This is followed by the MAPK subsystem (or the Raf-MEK-ERK pathway) which produces the double phosphorylated ERK upon being activated by Ras. Although separate models exist in the literature at the subsystems level, a comprehensive model for the complete system including the important regulatory feedback loops is missing. Our dynamic model combines the existing subsystem models and studies their steady-state and dynamic interactions under feedback. We establish conditions under which bistability and oscillations exist for this important pathway. In particular, we show how the negative and positive feedback loops affect the dynamic characteristics that determine the cellular outcome.
NASA Astrophysics Data System (ADS)
Valdes, Raymond
The characterization of thermal barrier coating (TBC) systems is increasingly important because they enable gas turbine engines to operate at high temperatures and efficiency. Phase of photothermal emission analysis (PopTea) has been developed to analyze the thermal behavior of the ceramic top-coat of TBCs, as a nondestructive and noncontact method for measuring thermal diffusivity and thermal conductivity. Most TBC allocations are on actively-cooled high temperature turbine blades, which makes it difficult to precisely model heat transfer in the metallic subsystem. This reduces the ability of rote thermal modeling to reflect the actual physical conditions of the system and can lead to higher uncertainty in measured thermal properties. This dissertation investigates fundamental issues underpinning robust thermal property measurements that are adaptive to non-specific, complex, and evolving system characteristics using the PopTea method. A generic and adaptive subsystem PopTea thermal model was developed to account for complex geometry beyond a well-defined coating and substrate system. Without a priori knowledge of the subsystem characteristics, two different measurement techniques were implemented using the subsystem model. In the first technique, the properties of the subsystem were resolved as part of the PopTea parameter estimation algorithm; and, the second technique independently resolved the subsystem properties using a differential "bare" subsystem. The confidence in thermal properties measured using the generic subsystem model is similar to that from a standard PopTea measurement on a "well-defined" TBC system. Non-systematic bias-error on experimental observations in PopTea measurements due to generic thermal model discrepancies was also mitigated using a regression-based sensitivity analysis. The sensitivity analysis reported measurement uncertainty and was developed into a data reduction method to filter out these "erroneous" observations. It was found that the adverse impact of bias-error can be greatly reduced, leaving measurement observations with only random Gaussian noise in PopTea thermal property measurements. Quantifying the influence of the coating-substrate interface in PopTea measurements is important to resolving the thermal conductivity of the coating. However, the reduced significance of this interface in thicker coating systems can give rise to large uncertainties in thermal conductivity measurements. A first step towards improving PopTea measurements for such circumstances has been taken by implementing absolute temperature measurements using harmonically-sustained two-color pyrometry. Although promising, even small uncertainties in thermal emission observations were found to lead to significant noise in temperature measurements. However, PopTea analysis on bulk graphite samples were able to resolve its thermal conductivity to the expected literature values.
Virtual Engineering and Science Team - Reusable Autonomy for Spacecraft Subsystems
NASA Technical Reports Server (NTRS)
Bailin, Sidney C.; Johnson, Michael A.; Rilee, Michael L.; Truszkowski, Walt; Thompson, Bryan; Day, John H. (Technical Monitor)
2002-01-01
In this paper we address the design, development, and evaluation of the Virtual Engineering and Science Team (VEST) tool - a revolutionary way to achieve onboard subsystem/instrument autonomy. VEST directly addresses the technology needed for advanced autonomy enablers for spacecraft subsystems. It will significantly support the efficient and cost effective realization of on-board autonomy and contribute directly to realizing the concept of an intelligent autonomous spacecraft. VEST will support the evolution of a subsystem/instrument model that is probably correct and from that model the automatic generation of the code needed to support the autonomous operation of what was modeled. VEST will directly support the integration of the efforts of engineers, scientists, and software technologists. This integration of efforts will be a significant advancement over the way things are currently accomplished. The model, developed through the use of VEST, will be the basis for the physical construction of the subsystem/instrument and the generated code will support its autonomous operation once in space. The close coupling between the model and the code, in the same tool environment, will help ensure that correct and reliable operational control of the subsystem/instrument is achieved.VEST will provide a thoroughly modern interface that will allow users to easily and intuitively input subsystem/instrument requirements and visually get back the system's reaction to the correctness and compatibility of the inputs as the model evolves. User interface/interaction, logic, theorem proving, rule-based and model-based reasoning, and automatic code generation are some of the basic technologies that will be brought into play in realizing VEST.
ERIC Educational Resources Information Center
Marcum, Deanna; Boss, Richard
1982-01-01
Discusses four automated serials control systems which have been installed by at least six general libraries: OCLC's Serials Control Subsystem, Faxon's LINX, Ebsco's EBSCONET, and CLASS' CHECKMATE. Features of each system, accessibility, and costs are noted. (EJS)
Space station WP-04 power system. Volume 1: Executive summary
NASA Technical Reports Server (NTRS)
Hallinan, G. J.
1987-01-01
Major study activities and results of the phase B study contract for the preliminary design of the space station Electrical Power System (EPS) are summarized. The areas addressed include the general system design, man-tended option, automation and robotics, evolutionary growth, software development environment, advanced development, customer accommodations, operations planning, product assurance, and design and development phase planning. The EPS consists of a combination photovoltaic and solar dynamic power generation subsystem and a power management and distribution (PMAD) subsystem. System trade studies and costing activities are also summarized.
Large-payload earth-orbit transportation with electric propulsion
NASA Technical Reports Server (NTRS)
Stearns, J. W.
1976-01-01
Economical unmanned earth orbit transportation for large payloads is evaluated. The high exhaust velocity achievable with electric propulsion is attractive because it minimizes the propellant that must be carried to low earth orbit. Propellant transport is a principal cost item. Electric propulsion subsystems utilizing advanced ion thrusters are compared to magnetoplasmadynamic (MPD) thrust subsystems. For very large payloads, a large lift vehicle is needed to low earth orbit, and argon propellant is required for electric propulsion. Under these circumstances, the MPD thruster is shown to be desirable over the ion thruster for earth orbit transportation.
Common modular avionics - Partitioning and design philosophy
NASA Astrophysics Data System (ADS)
Scott, D. M.; Mulvaney, S. P.
The design objectives and definition criteria for common modular hardware that will perform digital processing functions in multiple avionic subsystems are examined. In particular, attention is given to weapon system-level objectives, such as increased supportability, reduced life cycle costs, and increased upgradability. These objectives dictate the following overall modular design goals: reduce test equipment requirements; have a large number of subsystem applications; design for architectural growth; and standardize for technology transparent implementations. Finally, specific partitioning criteria are derived on the basis of the weapon system-level objectives and overall design goals.
1989-05-01
Faced with complaints about lengthy and costly developments , rapid obsolescence, and excessive costs of ownership, we have all heard the following...microwave integrated circuits raises similar system and sub-system issues. Microprocessor developments raise new questions regarding the trade-offs between...imply the need for and utilization of more specialists, but future avionics developments will also require systems-oriented engineess. By definition
Entry Descent and Landing Workshop Proceedings. Volume 1; Cost Drivers
NASA Technical Reports Server (NTRS)
Wright, Henry
2015-01-01
Provide some perspective on characteristics or features which drive the cost of the EDL Instrumentation. Using MEDLI, MEDLI2, EFT1, and Ares I-X as case studies. Need to consider what program is funding the effort and how that program likes to manage projects. Need to define the limits of the measurement subsystem - what is being provided and implemented - and by whom. The yearly end of fiscal year drama will always introduce uncertainty which will impact the cost - and cost phasing.
NASA Technical Reports Server (NTRS)
Boothe, W. A.; Corman, J. C.; Johnson, G. G.; Cassel, T. A. V.
1976-01-01
Results are presented of an investigation of gasification and clean fuels from coal. Factors discussed include: coal and coal transportation costs; clean liquid and gas fuel process efficiencies and costs; and cost, performance, and environmental intrusion elements of the integrated low-Btu coal gasification system. Cost estimates for the balance-of-plant requirements associated with advanced energy conversion systems utilizing coal or coal-derived fuels are included.
Impact of propulsion system R and D on electric vehicle performance and cost
NASA Technical Reports Server (NTRS)
Schwartz, H. J.; Gordan, A. L.
1980-01-01
The efficiency, weight, and manufacturing cost of the propulsion subsystem (motor, motor controller, transmission, and differential, but excluding the battery) are major factors in the purchase price and cost of ownership of a traffic-compatible electric vehicle. The relative impact of each was studied, and the conclusions reached are that propulsion system technology advances can result in a major reduction of the sticker price of an electric vehicle and a smaller, but significant, reduction in overall cost of ownership.
Bi-Level Integrated System Synthesis (BLISS)
NASA Technical Reports Server (NTRS)
Sobieszczanski-Sobieski, Jaroslaw; Agte, Jeremy S.; Sandusky, Robert R., Jr.
1998-01-01
BLISS is a method for optimization of engineering systems by decomposition. It separates the system level optimization, having a relatively small number of design variables, from the potentially numerous subsystem optimizations that may each have a large number of local design variables. The subsystem optimizations are autonomous and may be conducted concurrently. Subsystem and system optimizations alternate, linked by sensitivity data, producing a design improvement in each iteration. Starting from a best guess initial design, the method improves that design in iterative cycles, each cycle comprised of two steps. In step one, the system level variables are frozen and the improvement is achieved by separate, concurrent, and autonomous optimizations in the local variable subdomains. In step two, further improvement is sought in the space of the system level variables. Optimum sensitivity data link the second step to the first. The method prototype was implemented using MATLAB and iSIGHT programming software and tested on a simplified, conceptual level supersonic business jet design, and a detailed design of an electronic device. Satisfactory convergence and favorable agreement with the benchmark results were observed. Modularity of the method is intended to fit the human organization and map well on the computing technology of concurrent processing.
Microcontroller based system for electrical breakdown time delay measurement in gas-filled devices.
Pejović, Milić M; Denić, Dragan B; Pejović, Momčilo M; Nešić, Nikola T; Vasović, Nikola
2010-10-01
This paper presents realization of a digital embedded system for measuring electrical breakdown time delay. The proposed system consists of three major parts: dc voltage supply, analog subsystem, and a digital subsystem. Any dc power source with the range from 100 to 1000 V can be used in this application. The analog subsystem should provide fast and accurate voltage switching on the testing device as well as transform the signals that represent the voltage pulse on the device and the device breakdown into the form suitable for detection by a digital subsystem. The insulated gate bipolar transistor IRG4PH40KD driven by TC429 MOSFET driver is used for high voltage switching on the device. The aim of a digital subsystem is to detect the signals from the analog subsystem and to measure the elapsed time between their occurrences. Moreover, the digital subsystem controls various parameters that influence time delay and provides fast data storage for a large number of measured data. For this propose, we used the PIC18F4550 microcontroller with a full-speed compatible universal serial bus (USB) engine. Operation of this system is verified on different commercial and custom made gas devices with different structure and breakdown mechanisms. The electrical breakdown time delay measurements have been carried out as a function of several parameters, which dominantly influence electrical breakdown time delay. The obtained results have been verified using statistical methods, and they show good agreement with the theory. The proposed system shows good repeatability, sensitivity, and stability for measuring the electrical breakdown time delay.
Microcontroller based system for electrical breakdown time delay measurement in gas-filled devices
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pejovic, Milic M.; Denic, Dragan B.; Pejovic, Momcilo M.
2010-10-15
This paper presents realization of a digital embedded system for measuring electrical breakdown time delay. The proposed system consists of three major parts: dc voltage supply, analog subsystem, and a digital subsystem. Any dc power source with the range from 100 to 1000 V can be used in this application. The analog subsystem should provide fast and accurate voltage switching on the testing device as well as transform the signals that represent the voltage pulse on the device and the device breakdown into the form suitable for detection by a digital subsystem. The insulated gate bipolar transistor IRG4PH40KD driven bymore » TC429 MOSFET driver is used for high voltage switching on the device. The aim of a digital subsystem is to detect the signals from the analog subsystem and to measure the elapsed time between their occurrences. Moreover, the digital subsystem controls various parameters that influence time delay and provides fast data storage for a large number of measured data. For this propose, we used the PIC18F4550 microcontroller with a full-speed compatible universal serial bus (USB) engine. Operation of this system is verified on different commercial and custom made gas devices with different structure and breakdown mechanisms. The electrical breakdown time delay measurements have been carried out as a function of several parameters, which dominantly influence electrical breakdown time delay. The obtained results have been verified using statistical methods, and they show good agreement with the theory. The proposed system shows good repeatability, sensitivity, and stability for measuring the electrical breakdown time delay.« less
Multi-rate DPSK optical transceivers for free-space applications
NASA Astrophysics Data System (ADS)
Caplan, D. O.; Carney, J. J.; Fitzgerald, J. J.; Gaschits, I.; Kaminsky, R.; Lund, G.; Hamilton, S. A.; Magliocco, R. J.; Murphy, R. J.; Rao, H. G.; Spellmeyer, N. W.; Wang, J. P.
2014-03-01
We describe a flexible high-sensitivity laser communication transceiver design that can significantly benefit performance and cost of NASA's satellite-based Laser Communications Relay Demonstration. Optical communications using differential phase shift keying, widely deployed for use in long-haul fiber-optic networks, is well known for its superior sensitivity and link performance over on-off keying, while maintaining a relatively straightforward design. However, unlike fiber-optic links, free-space applications often require operation over a wide dynamic range of power due to variations in link distance and channel conditions, which can include rapid kHz-class fading when operating through the turbulent atmosphere. Here we discuss the implementation of a robust, near-quantum-limited multi-rate DPSK transceiver, co-located transmitter and receiver subsystems that can operate efficiently over the highly-variable free-space channel. Key performance features will be presented on the master oscillator power amplifier (MOPA) based TX, including a wavelength-stabilized master laser, high-extinction-ratio burst-mode modulator, and 0.5 W single polarization power amplifier, as well as low-noise optically preamplified DSPK receiver and built-in test capabilities.
Brake System Design Optimization : Volume 2. Supplemental Data.
DOT National Transportation Integrated Search
1981-04-01
Existing freight car braking systems, components, and subsystems are characterized both physically and functionally, and life-cycle costs are examined. Potential improvements to existing systems previously proposed or available are identified and des...
Brake System Design Optimization. Volume II : Supplemental Data.
DOT National Transportation Integrated Search
1981-06-01
Existing freight car braking systems, components, and subsystems are characterized both physically and functionally, and life-cycle costs are examined. Potential improvements to existing systems previously proposed or available are identified and des...
Solar thermal technology evaluation, fiscal year 1982. Volume 2: Technical
NASA Technical Reports Server (NTRS)
1983-01-01
The technology base of solar thermal energy is investigated. The materials, components, subsystems, and processes capable of meeting specific energy cost targets are emphasized, as are system efficiency and reliability.
NASA Technical Reports Server (NTRS)
Behling, Michael; Buchman, Donald; Marcus, Andres; Procopis, Stephanie; Wassgren, Carl; Ziemer, Sarah
1990-01-01
A proposal for an exploratory spacecraft mission to Pluto/Charon system was written in response to the request for proposal for an unmannned probe to pluto (RFP). The design requirements of the RFP are presented and under the guidance of these requirements, the spacecraft Intrepid was designed. The RPF requirement that was of primary importance is the minimization of cost. Also, the reduction of flight time was of extreme importance because the atmosphere of Pluto is expected to collapse close to the Year 2020. If intrepid should arrive after the collapse, the mission would be a failure; for Pluto would be only a solid rock of ice. The topics presented include: (1) scientific instrumentation; (2) mission management, planning, and costing; (3) power and propulsion subsystem; (4) structural subsystem; (5) command, control, and communications; and (6) attitude and articulation control.
Engine Systems Ownership Cost Reduction - Aircraft Propulsion Subsystems Integration (APSI)
1975-08-01
compreusor fabrication costs. Hybrid Radial Compresscr Diffuser - Combining both the radial and axial sections of a standard diffuser into a single cascade...compressor diffuser by using a single mixed-flow diffuser instead of the separate radial and axial diffuser stator rows. The proposed mixed-flow diffuser...to an axial diffuser. A cost analyses of the hybrid radial diffuser was made and compared to baseline configuration ( radial and axial diffusers). The
Normal-Mode Splitting in a Weakly Coupled Optomechanical System
NASA Astrophysics Data System (ADS)
Rossi, Massimiliano; Kralj, Nenad; Zippilli, Stefano; Natali, Riccardo; Borrielli, Antonio; Pandraud, Gregory; Serra, Enrico; Di Giuseppe, Giovanni; Vitali, David
2018-02-01
Normal-mode splitting is the most evident signature of strong coupling between two interacting subsystems. It occurs when two subsystems exchange energy between themselves faster than they dissipate it to the environment. Here we experimentally show that a weakly coupled optomechanical system at room temperature can manifest normal-mode splitting when the pump field fluctuations are antisquashed by a phase-sensitive feedback loop operating close to its instability threshold. Under these conditions the optical cavity exhibits an effectively reduced decay rate, so that the system is effectively promoted to the strong coupling regime.
Intelligent Engine Systems Work Element 1.3: Sub System Health Management
NASA Technical Reports Server (NTRS)
Ashby, Malcolm; Simpson, Jeffrey; Singh, Anant; Ferguson, Emily; Frontera, mark
2005-01-01
The objectives of this program were to develop health monitoring systems and physics-based fault detection models for engine sub-systems including the start, lubrication, and fuel. These models will ultimately be used to provide more effective sub-system fault identification and isolation to reduce engine maintenance costs and engine down-time. Additionally, the bearing sub-system health is addressed in this program through identification of sensing requirements, a review of available technologies and a demonstration of a demonstration of a conceptual monitoring system for a differential roller bearing. This report is divided into four sections; one for each of the subtasks. The start system subtask is documented in section 2.0, the oil system is covered in section 3.0, bearing in section 4.0, and the fuel system is presented in section 5.0.
Zhao, Meng; Ding, Baocang
2015-03-01
This paper considers the distributed model predictive control (MPC) of nonlinear large-scale systems with dynamically decoupled subsystems. According to the coupled state in the overall cost function of centralized MPC, the neighbors are confirmed and fixed for each subsystem, and the overall objective function is disassembled into each local optimization. In order to guarantee the closed-loop stability of distributed MPC algorithm, the overall compatibility constraint for centralized MPC algorithm is decomposed into each local controller. The communication between each subsystem and its neighbors is relatively low, only the current states before optimization and the optimized input variables after optimization are being transferred. For each local controller, the quasi-infinite horizon MPC algorithm is adopted, and the global closed-loop system is proven to be exponentially stable. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.
Describing long-range charge-separation processes with subsystem density-functional theory
DOE Office of Scientific and Technical Information (OSTI.GOV)
Solovyeva, Alisa; Neugebauer, Johannes, E-mail: j.neugebauer@uni-muenster.de; Pavanello, Michele, E-mail: m.pavanello@rutgers.edu
2014-04-28
Long-range charge-transfer processes in extended systems are difficult to describe with quantum chemical methods. In particular, cost-effective (non-hybrid) approximations within time-dependent density functional theory (DFT) are not applicable unless special precautions are taken. Here, we show that the efficient subsystem DFT can be employed as a constrained DFT variant to describe the energetics of long-range charge-separation processes. A formal analysis of the energy components in subsystem DFT for such excitation energies is presented, which demonstrates that both the distance dependence and the long-range limit are correctly described. In addition, electronic couplings for these processes as needed for rate constants inmore » Marcus theory can be obtained from this method. It is shown that the electronic structure of charge-separated states constructed by a positively charged subsystem interacting with a negatively charged one is difficult to converge — charge leaking from the negative subsystem to the positive one can occur. This problem is related to the delocalization error in DFT and can be overcome with asymptotically correct exchange–correlation (XC) potentials or XC potentials including a sufficiently large amount of exact exchange. We also outline an approximate way to obtain charge-transfer couplings between locally excited and charge-separated states.« less
Advanced life support control/monitor instrumentation concepts for flight application
NASA Technical Reports Server (NTRS)
Heppner, D. B.; Dahlhausen, M. J.; Fell, R. B.
1986-01-01
Development of regenerative Environmental Control/Life Support Systems requires instrumentation characteristics which evolve with successive development phases. As the development phase moves toward flight hardware, the system availability becomes an important design aspect which requires high reliability and maintainability. This program was directed toward instrumentation designs which incorporate features compatible with anticipated flight requirements. The first task consisted of the design, fabrication and test of a Performance Diagnostic Unit. In interfacing with a subsystem's instrumentation, the Performance Diagnostic Unit is capable of determining faulty operation and components within a subsystem, perform on-line diagnostics of what maintenance is needed and accept historical status on subsystem performance as such information is retained in the memory of a subsystem's computerized controller. The second focus was development and demonstration of analog signal conditioning concepts which reduce the weight, power, volume, cost and maintenance and improve the reliability of this key assembly of advanced life support instrumentation. The approach was to develop a generic set of signal conditioning elements or cards which can be configured to fit various subsystems. Four generic sensor signal conditioning cards were identified as being required to handle more than 90 percent of the sensors encountered in life support systems. Under company funding, these were detail designed, built and successfully tested.
NASA Astrophysics Data System (ADS)
Liu, D.; Tian, F.; Lin, M.; Sivapalan, M.
2014-12-01
The complex interactions and feedbacks between humans and water are very essential issues but are poorly understood in the newly proposed discipline of socio-hydrology (Sivapalan et al., 2012). An exploratory model with the appropriate level of simplification can be valuable to improve our understanding of the co-evolution and self-organization of socio-hydrological systems driven by interactions and feedbacks operating at different scales. In this study, a simple coupled modeling framework for socio-hydrology co-evolution is developed for the Tarim River Basin in Western China, and is used to illustrate the explanatory power of such a model. The study area is the mainstream of the Tarim River, which is divided into two modeling units. The socio-hydrological system is composed of four parts, i.e., social sub-system, economic sub-system, ecological sub-system, and hydrological sub-system. In each modeling unit, four coupled ordinary differential equations are used to simulate the dynamics of the social sub-system represented by human population, the economic sub-system represented by irrigated crop area, the ecological sub-system represented by natural vegetation cover and the hydrological sub-system represented by stream discharge. The coupling and feedback processes of the four dominant sub-systems (and correspondingly four state variables) are integrated into several internal system characteristics interactively and jointly determined by themselves and by other coupled systems. For example, the stream discharge is coupled to the irrigated crop area by the colonization rate and mortality rate of the irrigated crop area in the upper reach and the irrigated area is coupled to stream discharge through irrigation water consumption. The co-evolution of the Tarim socio-hydrological system is then analyzed within this modeling framework to gain insights into the overall system dynamics and its sensitivity to the external drivers and internal system variables. In the modeling framework, the state of each subsystem is holistically described by one state variable and the framework is flexible enough to comprise more processes and constitutive relationships if they are needed to illustrate the interaction and feedback mechanisms of the human-water system.
Brake System Design Optimization : Volume 1. A Survey and Assessment.
DOT National Transportation Integrated Search
1978-06-01
Existing freight car braking systems, components, and subsystems are characterized both physically and functionally, and life-cycle costs are examined. Potential improvements to existing systems previously proposed or available are identified and des...
Finding the Balance of Autonomy on-Board Versus Man-Triggered Actions from Ground
NASA Astrophysics Data System (ADS)
Lundin, Stefan
Odin is a scientific, 3-axis stabilised, fine-pointing, small satellite with a sensitive payload that provides high quality spectroscopy data in the optical, mm and submm regions. End-users are atmosphere scientists as well as astronomers in Canada, France, Finland and Sweden. The satellite was successfully injected into orbit in February 2001 by a START-1 rocket. Designed, developed and procured by the Swedish Space Corporation, Odin is now operated by our company ten times per day from its dedicated control centre located at Esrange in the northern Sweden. The usage of the same organisation gave us the possibility to find an efficient trade-off between "degree of autonomy on-board" versus "future operational cost".. The necessity of sophisticated, hard-to-develop autonomy was judged against mission objectives, spacecraft safety and additional operational cost. In the paper, the operational philosophy of Odin is presented and based on gathered experience in-orbit, the most essential autonomous functions on-board are identified. Odin is a low cost satellite with very high performance. For comparison, it is capable of unique science with a pointing accuracy better than 15 arcseconds. The procurement and launch of the satellite ended up to a total cost of 45 MUSD using a tight project team of only ten persons truly responsible for their subsystems. The same amount of people now operates the satellite and staffs the Mission Control Centre.
NASA Technical Reports Server (NTRS)
Marston, C. H.; Alyea, F. N.; Bender, D. J.; Davis, L. K.; Dellinger, T. C.; Hnat, J. G.; Komito, E. H.; Peterson, C. A.; Rogers, D. A.; Roman, A. J.
1980-01-01
The performance and cost of moderate technology coal-fired open cycle MHD/steam power plant designs which can be expected to require a shorter development time and have a lower development cost than previously considered mature OCMHD/steam plants were determined. Three base cases were considered: an indirectly-fired high temperature air heater (HTAH) subsystem delivering air at 2700 F, fired by a state of the art atmospheric pressure gasifier, and the HTAH subsystem was deleted and oxygen enrichment was used to obtain requisite MHD combustion temperature. Coal pile to bus bar efficiencies in ease case 1 ranged from 41.4% to 42.9%, and cost of electricity (COE) was highest of the three base cases. For base case 2 the efficiency range was 42.0% to 45.6%, and COE was lowest. For base case 3 the efficiency range was 42.9% to 44.4%, and COE was intermediate. The best parametric cases in bases cases 2 and 3 are recommended for conceptual design. Eventual choice between these approaches is dependent on further evaluation of the tradeoffs among HTAH development risk, O2 plant integration, and further refinements of comparative costs.
Kurochkin, Ilya O; Etzkorn, Markus; Buchwalter, David; Leamy, Larry; Sokolova, Inna M
2011-01-01
Cadmium (Cd) is a toxic metal and an important environmental pollutant that can strongly affect mitochondrial function and bioenergetics in animals. We investigated the mechanisms of Cd action on mitochondrial function of a marine mollusk (the eastern oyster Crassostrea virginica) by performing a top-down control analysis of the three major mitochondrial subsystems (substrate oxidation, proton leak, and phosphorylation). Our results showed that the substrate oxidation and proton leak subsystems are the main targets for Cd toxicity in oyster mitochondria. Exposure to 12.5 μM Cd strongly inhibited the substrate oxidation subsystem and stimulated the proton conductance across the inner mitochondrial membrane. Proton conductance was also elevated and substrate oxidation inhibited by Cd in the presence of a mitochondrially targeted antioxidant, MitoVitE, indicating that Cd effects on these subsystems were to a large extent ROS independent. Cd did not affect the kinetics of the phosphorylation system, indicating that it has negligible effects on F₁, F(O) ATP synthase and/or the adenine nucleotide transporter in oyster mitochondria. Cd exposure altered the patterns of control over mitochondrial respiration, increasing the degree of control conferred by the substrate oxidation subsystem, especially in resting (state 4) mitochondria. Taken together, these data suggest that Cd-induced decrease of mitochondrial efficiency and ATP production are predominantly driven by the high sensitivity of substrate oxidation and proton leak subsystems to this metal.
Cold-End Subsystem Testing for the Fission Power System Technology Demonstration Unit
NASA Technical Reports Server (NTRS)
Briggs, Mazwell; Gibson, Marc; Ellis, David; Sanzi, James
2013-01-01
The Fission Power System (FPS) Technology Demonstration Unit (TDU) consists of a pumped sodiumpotassium (NaK) loop that provides heat to a Stirling Power Conversion Unit (PCU), which converts some of that heat into electricity and rejects the waste heat to a pumped water loop. Each of the TDU subsystems is being tested independently prior to full system testing at the NASA Glenn Research Center. The pumped NaK loop is being tested at NASA Marshall Space Flight Center; the Stirling PCU and electrical controller are being tested by Sunpower Inc.; and the pumped water loop is being tested at Glenn. This paper describes cold-end subsystem setup and testing at Glenn. The TDU cold end has been assembled in Vacuum Facility 6 (VF 6) at Glenn, the same chamber that will be used for TDU testing. Cold-end testing in VF 6 will demonstrate functionality; validated coldend fill, drain, and emergency backup systems; and generated pump performance and system pressure drop data used to validate models. In addition, a low-cost proof-of concept radiator has been built and tested at Glenn, validating the design and demonstrating the feasibility of using low-cost metal radiators as an alternative to highcost composite radiators in an end-to-end TDU test.
Advanced Exploration Systems Atmosphere Resource Recovery and Environmental Monitoring
NASA Technical Reports Server (NTRS)
Perry, J.; Abney, M.; Conrad, R.; Garber, A.; Howard, D.; Kayatin, M.; Knox, J.; Newton, R.; Parrish, K.; Roman, M.;
2016-01-01
In September 2011, the Atmosphere Resource Recovery and Environmental Monitoring (ARREM) project was commissioned by NASA's Advanced Exploration Systems program to advance Atmosphere Revitalization Subsystem (ARS) and Environmental Monitoring Subsystem (EMS) technologies for enabling future crewed space exploration missions beyond low Earth orbit. The ARREM project's period of performance covered U.S. Government fiscal years 2012-2014. The ARREM project critically assessed the International Space Station (ISS) ARS and EMS architectures and process technologies as the foundation for an architecture suitable for deep space exploration vehicles. The project's technical content included technical tasks focused on improving the reliability and life cycle cost of ARS and EMS technologies as well as reducing future flight project developmental risk and design, development, test, and evaluation costs. Targeted technology development and maturation tasks, including key technical trade assessments, were accomplished and integrated ARS architectures were demonstrated. The ARREM project developed, demonstrated, and tested leading process technology candidates and subsystem architectures that met or exceeded key figures of merit, addressed capability gaps, and significantly improved the efficiency, safety, and reliability over the state-of-the-art ISS figures of merit. Promising EMS instruments were developed and functionally demonstrated in a simulated cabin environment. The project's technical approach and results are described and recommendations for continued development are provided.
ARTEMIS: a collaborative framework for health care.
Reddy, R; Jagannathan, V; Srinivas, K; Karinthi, R; Reddy, S M; Gollapudy, C; Friedman, S
1993-01-01
Patient centered healthcare delivery is an inherently collaborative process. This involves a wide range of individuals and organizations with diverse perspectives: primary care physicians, hospital administrators, labs, clinics, and insurance. The key to cost reduction and quality improvement in health care is effective management of this collaborative process. The use of multi-media collaboration technology can facilitate timely delivery of patient care and reduce cost at the same time. During the last five years, the Concurrent Engineering Research Center (CERC), under the sponsorship of DARPA (Defense Advanced Research Projects Agency, recently renamed ARPA) developed a number of generic key subsystems of a comprehensive collaboration environment. These subsystems are intended to overcome the barriers that inhibit the collaborative process. Three subsystems developed under this program include: MONET (Meeting On the Net)--to provide consultation over a computer network, ISS (Information Sharing Server)--to provide access to multi-media information, and PCB (Project Coordination Board)--to better coordinate focussed activities. These systems have been integrated into an open environment to enable collaborative processes. This environment is being used to create a wide-area (geographically distributed) research testbed under DARPA sponsorship, ARTEMIS (Advance Research Testbed for Medical Informatics) to explore the collaborative health care processes. We believe this technology will play a key role in the current national thrust to reengineer the present health-care delivery system.
Optimization of municipal pressure pumping station layout and sewage pipe network design
NASA Astrophysics Data System (ADS)
Tian, Jiandong; Cheng, Jilin; Gong, Yi
2018-03-01
Accelerated urbanization places extraordinary demands on sewer networks; thus optimization research to improve the design of these systems has practical significance. In this article, a subsystem nonlinear programming model is developed to optimize pumping station layout and sewage pipe network design. The subsystem model is expanded into a large-scale complex nonlinear programming system model to find the minimum total annual cost of the pumping station and network of all pipe segments. A comparative analysis is conducted using the sewage network in Taizhou City, China, as an example. The proposed method demonstrated that significant cost savings could have been realized if the studied system had been optimized using the techniques described in this article. Therefore, the method has practical value for optimizing urban sewage projects and provides a reference for theoretical research on optimization of urban drainage pumping station layouts.
Molten salt thermal energy storage subsystem for Solar Thermal Central Receiver plants
NASA Astrophysics Data System (ADS)
Wells, P. B.; Nassopoulos, G. P.
The development of a low-cost thermal energy storage subsystem for large solar plants is analyzed. Molten nitrate salt is used as both the plant's working fluid and as the storage medium. The storage system comprises a specially designed hot tank to hold salt at a storage temperature of 839 K (1050 F) and a separate carbon steel cold tank to hold the salt after its thermal energy has been extracted to generate steam. The hot tank is lined with insulating firebrick to lower the shell temperature to 561 K (550 F) so that a low-cost carbon steel shell can be used. A preliminary design is described for a large commercial-size plant (1200 MWht). Also described are a laboratory test program for the critical components and the design, construction, and test of a small-scale research experiment at the Central Receiver Test Facility in Albuquerque, New Mexico.
NASA Astrophysics Data System (ADS)
Noumaru, Junichi; Kawai, Jun A.; Schubert, Kiaina; Yagi, Masafumi; Takata, Tadafumi; Winegar, Tom; Scanlon, Tim; Nishida, Takuhiro; Fox, Camron; Hayasaka, James; Forester, Jason; Uchida, Kenji; Nakamura, Isamu; Tom, Richard; Koura, Norikazu; Yamamoto, Tadahiro; Tanoue, Toshiya; Yamada, Toru
2008-07-01
Subaru Telescope has recently replaced most equipment of Subaru Telescope Network II with the new equipment which includes 124TB of RAID system for data archive. Switching the data storage from tape to RAID enables users to access the data faster. The STN-III dropped some important components of STN-II, such as supercomputers, development & testing subsystem for Subaru Observation Control System, or data processing subsystem. On the other hand, we invested more computers to the remote operation system. Thanks to IT innovations, our LAN as well as the network between Hilo and summit were upgraded to gigabit network at the similar or even reduced cost from the previous system. As the result of the redesigning of the computer system by more focusing on the observatory operation, we greatly reduced the total cost for computer rental, purchase and maintenance.
Autonomous flight and remote site landing guidance research for helicopters
NASA Technical Reports Server (NTRS)
Denton, R. V.; Pecklesma, N. J.; Smith, F. W.
1987-01-01
Automated low-altitude flight and landing in remote areas within a civilian environment are investigated, where initial cost, ongoing maintenance costs, and system productivity are important considerations. An approach has been taken which has: (1) utilized those technologies developed for military applications which are directly transferable to a civilian mission; (2) exploited and developed technology areas where new methods or concepts are required; and (3) undertaken research with the potential to lead to innovative methods or concepts required to achieve a manual and fully automatic remote area low-altitude and landing capability. The project has resulted in a definition of system operational concept that includes a sensor subsystem, a sensor fusion/feature extraction capability, and a guidance and control law concept. These subsystem concepts have been developed to sufficient depth to enable further exploration within the NASA simulation environment, and to support programs leading to the flight test.
NASA Technical Reports Server (NTRS)
Srivastava, Ashok N.; Mylaraswmay, Dinkar; Mah, Robert W.; Cooper, Eric G.
2011-01-01
At the aircraft level, a Vehicle-Level Reasoning System (VLRS) can be developed to provide aircraft with at least two significant capabilities: improvement of aircraft safety due to enhanced monitoring and reasoning about the aircrafts health state, and also potential cost savings by enabling Condition Based Maintenance (CBM). Along with the benefits of CBM, an important challenge facing aviation safety today is safeguarding against system and component failures and malfunctions. Faults can arise in one or more aircraft subsystem their effects in one system may propagate to other subsystems, and faults may interact.
Low-cost Large Aperture Telescopes for Optical Communications
NASA Technical Reports Server (NTRS)
Hemmati, Hamid
2006-01-01
Low-cost, large-aperture optical receivers are required to form an affordable optical ground receiver network for laser communications. Among the ground receiver station's multiple subsystems, here, we only discuss the ongoing research activities aimed at reducing the cost of the large-size optics on the receiver. Experimental results of two different approaches for fabricating low-cost mirrors of wavefront quality on the order of 100-200X the diffraction limit are described. Laboratory-level effort are underway to improve the surface figure to better than 20X the diffraction limit.
NASA Air Force Cost Model (NAFCOM): Capabilities and Results
NASA Technical Reports Server (NTRS)
McAfee, Julie; Culver, George; Naderi, Mahmoud
2011-01-01
NAFCOM is a parametric estimating tool for space hardware. Uses cost estimating relationships (CERs) which correlate historical costs to mission characteristics to predict new project costs. It is based on historical NASA and Air Force space projects. It is intended to be used in the very early phases of a development project. NAFCOM can be used at the subsystem or component levels and estimates development and production costs. NAFCOM is applicable to various types of missions (crewed spacecraft, uncrewed spacecraft, and launch vehicles). There are two versions of the model: a government version that is restricted and a contractor releasable version.
Applications of optical measurement technology in pollution gas monitoring at thermal power plants
NASA Astrophysics Data System (ADS)
Wang, Jian; Yu, Dahai; Ye, Huajun; Yang, Jianhu; Ke, Liang; Han, Shuanglai; Gu, Haitao; Chen, Yingbin
2011-11-01
This paper presents the work of using advanced optical measurement techniques to implement stack gas emission monitoring and process control. A system is designed to conduct online measurement of SO2/NOX and mercury emission from stacks and slipping NH3 of de-nitrification process. The system is consisted of SO2/NOX monitoring subsystem, mercury monitoring subsystem, and NH3 monitoring subsystem. The SO2/NOX monitoring subsystem is developed based on the ultraviolet differential optical absorption spectroscopy (UV-DOAS) technique. By using this technique, a linearity error less than +/-1% F.S. is achieved, and the measurement errors resulting from optical path contamination and light fluctuation are removed. Moreover, this subsystem employs in situ extraction and hot-wet line sampling technique to significantly reduce SO2 loss due to condensation and protect gas pipeline from corrosion. The mercury monitoring subsystem is used to measure the concentration of element mercury (Hg0), oxidized mercury (Hg2+), and total gaseous mercury (HgT) in the flue gas exhaust. The measurement of Hg with a low detection limit (0.1μg/m3) and a high sensitivity is realized by using cold vapor atom fluorescence spectroscopy (CVAFS) technique. This subsystem is also equipped with an inertial separation type sampling technique to prevent gas pipeline from being clogged and to reduce speciation mercury measurement error. The NH3 monitoring subsystem is developed to measure the concentration of slipping NH3 and then to help improving the efficiency of de-nitrification. The NH3 concentration as low as 0.1ppm is able to be measured by using the off-axis integrated cavity output spectroscopy (ICOS) and the tunable diode laser absorption spectroscopy (TDLAS) techniques. The problem of trace NH3 sampling loss is solved by applying heating the gas pipelines when the measurement is running.
NASA Astrophysics Data System (ADS)
Bearden, David A.; Duclos, Donald P.; Barrera, Mark J.; Mosher, Todd J.; Lao, Norman Y.
1997-12-01
Emerging technologies and micro-instrumentation are changing the way remote sensing spacecraft missions are developed and implemented. Government agencies responsible for procuring space systems are increasingly requesting analyses to estimate cost, performance and design impacts of advanced technology insertion for both state-of-the-art systems as well as systems to be built 5 to 10 years in the future. Numerous spacecraft technology development programs are being sponsored by Department of Defense (DoD) and National Aeronautics and Space Administration (NASA) agencies with the goal of enhancing spacecraft performance, reducing mass, and reducing cost. However, it is often the case that technology studies, in the interest of maximizing subsystem-level performance and/or mass reduction, do not anticipate synergistic system-level effects. Furthermore, even though technical risks are often identified as one of the largest cost drivers for space systems, many cost/design processes and models ignore effects of cost risk in the interest of quick estimates. To address these issues, the Aerospace Corporation developed a concept analysis methodology and associated software tools. These tools, collectively referred to as the concept analysis and design evaluation toolkit (CADET), facilitate system architecture studies and space system conceptual designs focusing on design heritage, technology selection, and associated effects on cost, risk and performance at the system and subsystem level. CADET allows: (1) quick response to technical design and cost questions; (2) assessment of the cost and performance impacts of existing and new designs/technologies; and (3) estimation of cost uncertainties and risks. These capabilities aid mission designers in determining the configuration of remote sensing missions that meet essential requirements in a cost- effective manner. This paper discuses the development of CADET modules and their application to several remote sensing satellite mission concepts.
NASA Technical Reports Server (NTRS)
Anthony, K.
1978-01-01
A description of the hot air collector is given that includes a history of development, a history of the materials development, and a program summary. The major portion of the solar energy system cost is the collector. Since the collector is the heart of the system and the most costly subsystem, reducing the cost of producing collectors in large quantities is a major goal. This solar collector is designed to heat air and/or water cheaply and efficiently through the use of solar energy.
Systems cost/performance analysis; study 2.3. Volume 3: Programmer's manual and user's guide
NASA Technical Reports Server (NTRS)
1975-01-01
The implementation of the entire systems cost/performance model as a digital computer program was studied. A discussion of the operating environment in which the program was written and checked, the program specifications such as discussions of logic and computational flow, the different subsystem models involved in the design of the spacecraft, and routines involved in the nondesign area such as costing and scheduling of the design were covered. Preliminary results for the DSCS-2 design are also included.
Earth Observatory Satellite system definition study. Report no. 3: Design/cost tradeoff studies
NASA Technical Reports Server (NTRS)
1974-01-01
The key issues in the Earth Observatory Satellite (EOS) program which are subject to configuration study and tradeoff are identified. The issue of a combined operational and research and development program is considered. It is stated that cost and spacecraft weight are the key design variables and design options are proposed in terms of these parameters. A cost analysis of the EOS program is provided. Diagrams of the satellite configuration and subsystem components are included.
NASA Technical Reports Server (NTRS)
Taube, L. J.
1972-01-01
This volume contains cost, schedule, and technical information on the following B-70 aircraft subsystems: air induction system, flight control, personnel accommodation and escape, alighting and arresting, mission and traffic control, flight indication, test instrumentation, and installation, checkout, and pre-flight.
An Unmanned Spacecraft Subsystem Cost Model for Advanced Mission Planning
NASA Technical Reports Server (NTRS)
Madrid, G.
1998-01-01
As a NASA center, the Jet Propulsion Laboratory (JPL) is committed to the concept of developing and launching a continuously improving series of smaller robotic space exploration missions in shorter intervals of time (faster, better, cheaper).
NASA Technical Reports Server (NTRS)
Gunning, George R.; Spapperi, Jeff; Wilkinson, Jeffrey P.; Eldred, Jim; Labij, Dennis; Strinni, Meredith
1990-01-01
A design proposal for an unmanned probe to Pluto is presented. The topics covered include: (1) scientific instrumentation; (2) mission management, planning, and costing; (3) power and propulsion system; (4) structural subsystem; (5) command, control, and communication; and (6) attitude and articulation control.
NASA Astrophysics Data System (ADS)
Piattoni, Jacopo; Candini, Gian Paolo; Pezzi, Giulio; Santoni, Fabio; Piergentili, Fabrizio
2012-12-01
This paper describes the design and the manufacturing of a Cubesat platform based on a plastic structure. The Cubesat structure has been realized in plastic material (ABS) using a "rapid prototyping" technique. The "rapid prototyping" technique has several advantages including fast implementation, accuracy in manufacturing small parts and low cost. Moreover, concerning the construction of a small satellite, this technique is very useful thanks to the accuracy achievable in details, which are sometimes difficult and expensive to realize with the use of tools machine. The structure must be able to withstand the launch loads. For this reason, several simulations using an FEM simulation and an intensive vibration test campaign have been performed in the system development and test phase. To demonstrate that this structure is suitable for hosting a complete satellite system, offering innovative integrated solutions, other subsystems have been developed and assembled. Despite its small size, this single unit (1U) Cubesat has a system for active attitude control, a redundant telecommunication system, a payload camera and a photovoltaic system based on high efficiency solar cells. The developed communication subsystem has small dimensions, low power consumption and low cost. An example of the innovations introduced is the antenna system, which has been manufactured inside the ABS structure. The communication protocol which has been implemented, the AX.25 protocol, is mainly used by radio amateurs. The communication system has the capability to transmit both telemetry and data from the payload, in this case a microcamera. The attitude control subsystem is based on an active magnetic system with magnetorquers for detumbling and momentum dumping and three reaction wheels for fine control. It has a total dimension of about 50×50×50 mm. A microcontroller implements the detumbling control law autonomously taking data from integrated magnetometers and executes pointing maneuvers on the basis of commands received in real time from ground. The subsystems developed for this Cubesat have also been designed to be scaled up for larger satellites such as 2U or 3U Cubesats. The additional volume can be used for more complex payloads. Thus the satellite can be used as a low cost platform for companies, institutions or universities to test components in space.
X-38 V201 Avionics Architecture
NASA Technical Reports Server (NTRS)
Bedos, Thierry; Anderson, Brian L.
1999-01-01
The X-38 is an experimental NASA project developing a core human capable spacecraft at a fraction of the cost of any previous human rated vehicle. The first operational derivative developed from the X-38 program will be the International Space Station (ISS) Crew Return Vehicle (CRV). Although the current X-38 vehicles are designed as re-entry vehicles only, the option exists to modify the vehicle for uses as an upward vehicle launched from an expendable launch vehicle or from the X-33 operational derivative. The Operational CRV, that will be derived from the X-38 spaceflight vehicle, will provide an emergency return capability from the International Space Station (ISS). The spacecraft can hold a crew of up to seven inside a pressurized cabin. The CRV is passively delivered to ISS, stays up to three year on-orbit attached to ISS in a passive mode with periodic functional checkout, before separation from ISS, de-orbit, entry and landing. The X-38 Vehicle 201 (V201) is being developed at NASA/JSC to demonstrate key technologies associated with the development of the CRV design. The X-38 flight test will validate the low cost development concept by demonstrating the entire station departure, re-entry, guidance and landing portions of the CRV mission. All new technologies and subsystems proposed for CRV will be validated during either the on orbit checkout or flight phases of the X-38 space flight test. The X-38 subsystems are required to be similar to those subsystems required for the CRV to the greatest extent possible. In many cases, the subsystems are identical to those that will be utilized on the Operational CRV.
Rommelmann, Vanessa; Setel, Philip W.; Hemed, Yusuf; Angeles, Gustavo; Mponezya, Hamisi; Whiting, David; Boerma, Ties
2005-01-01
OBJECTIVE: To examine the costs of complementary information generation activities in a resource-constrained setting and compare the costs and outputs of information subsystems that generate the statistics on poverty, health and survival required for monitoring, evaluation and reporting on health programmes in the United Republic of Tanzania. METHODS: Nine systems used by four government agencies or ministries were assessed. Costs were calculated from budgets and expenditure data made available by information system managers. System coverage, quality assurance and information production were reviewed using questionnaires and interviews. Information production was characterized in terms of 38 key sociodemographic indicators required for national programme monitoring. FINDINGS: In 2002-03 approximately US$ 0.53 was spent per Tanzanian citizen on the nine information subsystems that generated information on 37 of the 38 selected indicators. The census and reporting system for routine health service statistics had the largest participating populations and highest total costs. Nationally representative household surveys and demographic surveillance systems (which are not based on nationally representative samples) produced more than half the indicators and used the most rigorous quality assurance. Five systems produced fewer than 13 indicators and had comparatively high costs per participant. CONCLUSION: Policy-makers and programme planners should be aware of the many trade-offs with respect to system costs, coverage, production, representativeness and quality control when making investment choices for monitoring and evaluation. In future, formal cost-effectiveness studies of complementary information systems would help guide investments in the monitoring, evaluation and planning needed to demonstrate the impact of poverty-reduction and health programmes. PMID:16184275
A prototype PET/SPECT/X-rays scanner dedicated for whole body small animal studies.
Rouchota, Maritina; Georgiou, Maria; Fysikopoulos, Eleftherios; Fragogeorgi, Eirini; Mikropoulos, Konstantinos; Papadimitroulas, Panagiotis; Kagadis, George; Loudos, George
2017-01-01
To present a prototype tri-modal imaging system, consisting of a single photon emission computed tomography (SPET), a positron emission tomography (PET), and a computed tomography (CT) subsystem, evaluated in planar mode. The subsystems are mounted on a rotating gantry, so as to be able to allow tomographic imaging in the future. The system, designed and constructed by our group, allows whole body mouse imaging of competent performance and is currently, to the best of our knowledge, unequaled in a national and regional level. The SPET camera is based on two Position Sensitive Photomultiplier Tubes (PSPMT), coupled to a pixilated Sodium Iodide activated with Thallium (NaI(Tl)) scintillator, having an active area of 5x10cm 2 . The dual head PET camera is also based on two pairs of PSPMT, coupled to pixelated berillium germanium oxide (BGO) scintillators, having an active area of 5x10cm 2 . The X-rays system consists of a micro focus X-rays tube and a complementary metal-oxide-semiconductor (CMOS) detector, having an active area of 12x12cm 2 . The scintigraphic mode has a spatial resolution of 1.88mm full width at half maximum (FWHM) and a sensitivity of 107.5cpm/0.037MBq at the collimator surface. The coincidence PET mode has an average spatial resolution of 3.5mm (FWHM) and a peak sensitivity of 29.9cpm/0.037MBq. The X-rays spatial resolution is 3.5lp/mm and the contrast discrimination function value is lower than 2%. A compact tri-modal system was successfully built and evaluated for planar mode operation. The system has an efficient performance, allowing accurate and informative anatomical and functional imaging, as well as semi-quantitative results. Compared to other available systems, it provides a moderate but comparable performance, at a fraction of the cost and complexity. It is fully open, scalable and its main purpose is to support groups on a national and regional level and provide an open technological platform to study different detector components and acquisition strategies.
Space Shuttle Orbiter audio subsystem. [to communication and tracking system
NASA Technical Reports Server (NTRS)
Stewart, C. H.
1978-01-01
The selection of the audio multiplex control configuration for the Space Shuttle Orbiter audio subsystem is discussed and special attention is given to the evaluation criteria of cost, weight and complexity. The specifications and design of the subsystem are described and detail is given to configurations of the audio terminal and audio central control unit (ATU, ACCU). The audio input from the ACCU, at a signal level of -12.2 to 14.8 dBV, nominal range, at 1 kHz, was found to have balanced source impedance and a balanced local impedance of 6000 + or - 600 ohms at 1 kHz, dc isolated. The Lyndon B. Johnson Space Center (JSC) electroacoustic test laboratory, an audio engineering facility consisting of a collection of acoustic test chambers, analyzed problems of speaker and headset performance, multiplexed control data coupled with audio channels, and the Orbiter cabin acoustic effects on the operational performance of voice communications. This system allows technical management and project engineering to address key constraining issues, such as identifying design deficiencies of the headset interface unit and the assessment of the Orbiter cabin performance of voice communications, which affect the subsystem development.
Accelerating wavefunction in density-functional-theory embedding by truncating the active basis set
NASA Astrophysics Data System (ADS)
Bennie, Simon J.; Stella, Martina; Miller, Thomas F.; Manby, Frederick R.
2015-07-01
Methods where an accurate wavefunction is embedded in a density-functional description of the surrounding environment have recently been simplified through the use of a projection operator to ensure orthogonality of orbital subspaces. Projector embedding already offers significant performance gains over conventional post-Hartree-Fock methods by reducing the number of correlated occupied orbitals. However, in our first applications of the method, we used the atomic-orbital basis for the full system, even for the correlated wavefunction calculation in a small, active subsystem. Here, we further develop our method for truncating the atomic-orbital basis to include only functions within or close to the active subsystem. The number of atomic orbitals in a calculation on a fixed active subsystem becomes asymptotically independent of the size of the environment, producing the required O ( N 0 ) scaling of cost of the calculation in the active subsystem, and accuracy is controlled by a single parameter. The applicability of this approach is demonstrated for the embedded many-body expansion of binding energies of water hexamers and calculation of reaction barriers of SN2 substitution of fluorine by chlorine in α-fluoroalkanes.
Sun, Y.; Tong, C.; Trainor-Guitten, W. J.; ...
2012-12-20
The risk of CO 2 leakage from a deep storage reservoir into a shallow aquifer through a fault is assessed and studied using physics-specific computer models. The hypothetical CO 2 geological sequestration system is composed of three subsystems: a deep storage reservoir, a fault in caprock, and a shallow aquifer, which are modeled respectively by considering sub-domain-specific physics. Supercritical CO 2 is injected into the reservoir subsystem with uncertain permeabilities of reservoir, caprock, and aquifer, uncertain fault location, and injection rate (as a decision variable). The simulated pressure and CO 2/brine saturation are connected to the fault-leakage model as amore » boundary condition. CO 2 and brine fluxes from the fault-leakage model at the fault outlet are then imposed in the aquifer model as a source term. Moreover, uncertainties are propagated from the deep reservoir model, to the fault-leakage model, and eventually to the geochemical model in the shallow aquifer, thus contributing to risk profiles. To quantify the uncertainties and assess leakage-relevant risk, we propose a global sampling-based method to allocate sub-dimensions of uncertain parameters to sub-models. The risk profiles are defined and related to CO 2 plume development for pH value and total dissolved solids (TDS) below the EPA's Maximum Contaminant Levels (MCL) for drinking water quality. A global sensitivity analysis is conducted to select the most sensitive parameters to the risk profiles. The resulting uncertainty of pH- and TDS-defined aquifer volume, which is impacted by CO 2 and brine leakage, mainly results from the uncertainty of fault permeability. Subsequently, high-resolution, reduced-order models of risk profiles are developed as functions of all the decision variables and uncertain parameters in all three subsystems.« less
Photosynthesis energy factory: analysis, synthesis, and demonstration. Final report
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
This quantitative assessment of the potential of a combined dry-land Energy Plantation, wood-fired power plant, and algae wastewater treatment system demonstrates the cost-effectiveness of recycling certain by-products and effluents from one subsystem to another. Designed to produce algae up to the limit of the amount of carbon in municipal wastewater, the algae pond provides a positive cash credit, resulting mainly from the wastewater treatment credit, which may be used to reduce the cost of the Photosynthesis Energy Factory (PEF)-generated electricity. The algae pond also produces fertilizer, which reduces the cost of the biomass produced on the Energy Plantation, and somemore » gas. The cost of electricity was as low as 35 mills per kilowatt-hour for a typical municipally-owned PEF consisting of a 65-MWe power plant, a 144-acre algae pond, and a 33,000-acre Energy Plantation. Using only conventional or near-term technology, the most cost-effective algae pond for a PEF is the carbon-limited secondary treatment system. This system does not recycle CO/sub 2/ from the flue gas. Analysis of the Energy Plantation subsystem at 15 sites revealed that plantations of 24,000 to 36,000 acres produce biomass at the lowest cost per ton. The following sites are recommended for more detailed evaluation as potential demonstration sites: Pensacola, Florida; Jamestown, New York; Knoxville, Tennessee; Martinsville, Virginia, and Greenwood, South Carolina. A major possible extension of the PEF concept is to include the possibility for irrigation.« less
Magnetic Testing, and Modeling, Simulation and Analysis for Space Applications
NASA Technical Reports Server (NTRS)
Boghosian, Mary; Narvaez, Pablo; Herman, Ray
2012-01-01
The Aerospace Corporation (Aerospace) and Lockheed Martin Space Systems (LMSS) participated with Jet Propulsion Laboratory (JPL) in the implementation of a magnetic cleanliness program of the NASA/JPL JUNO mission. The magnetic cleanliness program was applied from early flight system development up through system level environmental testing. The JUNO magnetic cleanliness program required setting-up a specialized magnetic test facility at Lockheed Martin Space Systems for testing the flight system and a testing program with facility for testing system parts and subsystems at JPL. The magnetic modeling, simulation and analysis capability was set up and performed by Aerospace to provide qualitative and quantitative magnetic assessments of the magnetic parts, components, and subsystems prior to or in lieu of magnetic tests. Because of the sensitive nature of the fields and particles scientific measurements being conducted by the JUNO space mission to Jupiter, the imposition of stringent magnetic control specifications required a magnetic control program to ensure that the spacecraft's science magnetometers and plasma wave search coil were not magnetically contaminated by flight system magnetic interferences. With Aerospace's magnetic modeling, simulation and analysis and JPL's system modeling and testing approach, and LMSS's test support, the project achieved a cost effective approach to achieving a magnetically clean spacecraft. This paper presents lessons learned from the JUNO magnetic testing approach and Aerospace's modeling, simulation and analysis activities used to solve problems such as remnant magnetization, performance of hard and soft magnetic materials within the targeted space system in applied external magnetic fields.
Control structural interaction testbed: A model for multiple flexible body verification
NASA Technical Reports Server (NTRS)
Chory, M. A.; Cohen, A. L.; Manning, R. A.; Narigon, M. L.; Spector, V. A.
1993-01-01
Conventional end-to-end ground tests for verification of control system performance become increasingly complicated with the development of large, multiple flexible body spacecraft structures. The expense of accurately reproducing the on-orbit dynamic environment and the attendant difficulties in reducing and accounting for ground test effects limits the value of these tests. TRW has developed a building block approach whereby a combination of analysis, simulation, and test has replaced end-to-end performance verification by ground test. Tests are performed at the component, subsystem, and system level on engineering testbeds. These tests are aimed at authenticating models to be used in end-to-end performance verification simulations: component and subassembly engineering tests and analyses establish models and critical parameters, unit level engineering and acceptance tests refine models, and subsystem level tests confirm the models' overall behavior. The Precision Control of Agile Spacecraft (PCAS) project has developed a control structural interaction testbed with a multibody flexible structure to investigate new methods of precision control. This testbed is a model for TRW's approach to verifying control system performance. This approach has several advantages: (1) no allocation for test measurement errors is required, increasing flight hardware design allocations; (2) the approach permits greater latitude in investigating off-nominal conditions and parametric sensitivities; and (3) the simulation approach is cost effective, because the investment is in understanding the root behavior of the flight hardware and not in the ground test equipment and environment.
Diverse Redundant Systems for Reliable Space Life Support
NASA Technical Reports Server (NTRS)
Jones, Harry W.
2015-01-01
Reliable life support systems are required for deep space missions. The probability of a fatal life support failure should be less than one in a thousand in a multi-year mission. It is far too expensive to develop a single system with such high reliability. Using three redundant units would require only that each have a failure probability of one in ten over the mission. Since the system development cost is inverse to the failure probability, this would cut cost by a factor of one hundred. Using replaceable subsystems instead of full systems would further cut cost. Using full sets of replaceable components improves reliability more than using complete systems as spares, since a set of components could repair many different failures instead of just one. Replaceable components would require more tools, space, and planning than full systems or replaceable subsystems. However, identical system redundancy cannot be relied on in practice. Common cause failures can disable all the identical redundant systems. Typical levels of common cause failures will defeat redundancy greater than two. Diverse redundant systems are required for reliable space life support. Three, four, or five diverse redundant systems could be needed for sufficient reliability. One system with lower level repair could be substituted for two diverse systems to save cost.
Pioneer spacecraft operation at low and high spin rates
NASA Technical Reports Server (NTRS)
1973-01-01
The feasibility of executing major changes upward or downward from the nominal spin rate for which the Pioneer F&G spacecraft was designed was investigated along with the extent of system and subsystem modifications required to implement these mode changes in future spacecraft evolving from the baseline Pioneer F and G. Results of a previous study are re-examined and updated for an extended range of spin rate variations for missions that include outer planet orbiters, outer planet flyby and outer planet probe delivery. However, in the interest of design simplicity and cost economy, major modifications of the baseline Pioneer system and subsystem concept were avoided.
A computer simulator for development of engineering system design methodologies
NASA Technical Reports Server (NTRS)
Padula, S. L.; Sobieszczanski-Sobieski, J.
1987-01-01
A computer program designed to simulate and improve engineering system design methodology is described. The simulator mimics the qualitative behavior and data couplings occurring among the subsystems of a complex engineering system. It eliminates the engineering analyses in the subsystems by replacing them with judiciously chosen analytical functions. With the cost of analysis eliminated, the simulator is used for experimentation with a large variety of candidate algorithms for multilevel design optimization to choose the best ones for the actual application. Thus, the simulator serves as a development tool for multilevel design optimization strategy. The simulator concept, implementation, and status are described and illustrated with examples.
Photovoltaic power conditioning subsystem: State of the art and development opportunities
NASA Technical Reports Server (NTRS)
Krauthamer, S.; Bahrami, K.; Das, R.; Macie, T.; Rippel, W.
1984-01-01
Photovoltaic systems, the state of the art of power conditioning subsystem components, and the design and operational interaction between photovoltaic systems and host utilities are detailed in this document. Major technical issues relating to the design and development of power conditioning systems for photovoltaic application are considered; these include: (1) standards, guidelines, and specifications; (2) cost effective hardware design; (3) impact of advanced components on power conditioning development; (4) protection and safety; (5) quality of power; (6) system efficiency; and (7) system integration with the host utility. Theories of harmonic distortion and reactive power flow are discussed, and information about power conditioner hardware and manufacturers is provided.
NASA Technical Reports Server (NTRS)
Bowyer, J. M.
1984-01-01
The potential of a suitably designed and economically manufactured Stirling engine as the energy conversion subsystem of a paraboloidal dish-Stirling solar thermal power module was estimated. Results obtained by elementary cycle analyses were shown to match quite well the performance characteristics of an advanced kinematic Stirling engine, the United Stirling P-40, as established by current prototypes of the engine and by a more sophisticated analytic model of its advanced derivative. In addition to performance, brief consideration was given to other Stirling engine criteria such as durability, reliability, and serviceability. Production costs were not considered here.
Characterization of Subsystems for a WB-003 Single Stage Shuttle
NASA Technical Reports Server (NTRS)
MacConochie, Ian O.; Lepsch, Roger A., Jr. (Technical Monitor)
2002-01-01
Subsystems for an all oxygen-hydrogen-single-stage shuttle are characterized for a vehicle designated WB-003. Features of the vehicle include all-electric actuation, fiber optics for information circuitry, fuel cells for power generation, and extensive use of composites for structure. The vehicle is sized for the delivery of a 25,000 lb. payload to a space station orbit without crew. When crew are being delivered, they are carried in a module in the payload bay with escape and manual override capabilities. The underlying reason for undertaking this task is to provide a framework for the study of the operations costs of the newer shuttles.
Conceptual design and optimization for JET water detritiation system cryo-distillation facility
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lefebvre, X.; Hollingsworth, A.; Parracho, A.
2015-03-15
The aim of the Exhaust Detritiation System (EDS) of the JET Active Gas Handling System (AGHS) is to convert all Q-based species (Q{sub 2}, Q-hydrocarbons) into Q{sub 2}O (Q being indifferently H, D or T) which is then trapped on molecular sieve beds (MSB). Regenerating the saturated MSBs leads to the production of tritiated water which is stored in Briggs drums. An alternative disposal solution to offsite shipping, is to process the tritiated water onsite via the implementation of a Water Detritiation System (WDS) based, in part, on the combination of an electrolyser and a cryo-distillation (CD) facility. The CDmore » system will separate a Q{sub 2} mixture into a de-tritiated hydrogen stream for safe release and a tritiated stream for further processing on existing AGHS subsystems. A sensitivity study of the Souers' model using the simulation program ProSimPlus (edited by ProSim S.A.) has then been undertaken in order to perform an optimised dimensioning of the cryo-distillation system in terms of available cooling technologies, cost of investment, cost of operations, process performance and safety. (authors)« less
Using value-based total cost of ownership (TCO) measures to inform subsystem trade-offs
NASA Astrophysics Data System (ADS)
Radziwill, Nicole M.; DuPlain, Ronald F.
2010-07-01
Total Cost of Ownership (TCO) is a metric from management accounting that helps expose both the direct and indirect costs of a business decision. However, TCO can sometimes be too simplistic for "make vs. buy" decisions (or even choosing between competing design alternatives) when value and extensibility are more critical than total cost. A three-dimensional value-based TCO, which was developed to clarify product decisions for an observatory prior to Final Design Review (FDR), will be presented in this session. This value-based approach incorporates priority of requirements, satisfiability of requirements, and cost, and can be easily applied in any environment.
Mission management, planning, and cost: PULSE Attitude And Control Systems (AACS)
NASA Technical Reports Server (NTRS)
1990-01-01
The Pluto unmanned long-range scientific explorer (PULSE) is a probe that will do a flyby of Pluto. It is a low weight, relatively low costing vehicle which utilizes mostly off-the-shelf hardware, but not materials or techniques that will be available after 1999. A design, fabrication, and cost analysis is presented. PULSE will be launched within the first decade of the twenty-first century. The topics include: (1) scientific instrumentation; (2) mission management, planning, and costing; (3) power and propulsion systems; (4) structural subsystem; (5) command, control, and communication; and (6) attitude and articulation control.
Planetary spacecraft cost modeling utilizing labor estimating relationships
NASA Technical Reports Server (NTRS)
Williams, Raymond
1990-01-01
A basic computerized technology is presented for estimating labor hours and cost of unmanned planetary and lunar programs. The user friendly methodology designated Labor Estimating Relationship/Cost Estimating Relationship (LERCER) organizes the forecasting process according to vehicle subsystem levels. The level of input variables required by the model in predicting cost is consistent with pre-Phase A type mission analysis. Twenty one program categories were used in the modeling. To develop the model, numerous LER and CER studies were surveyed and modified when required. The result of the research along with components of the LERCER program are reported.
Life Cycle Cost Analysis of Shuttle-Derived Launch Vehicles, Volume 1
NASA Technical Reports Server (NTRS)
1982-01-01
The design, performance, and programmatic definition of shuttle derived launch vehicles (SDLV) established by two different contractors were assessed and the relative life cycle costs of space transportation systems using the shuttle alone were compared with costs for a mix of shuttles and SDLV's. The ground rules and assumptions used in the evaluation are summarized and the work breakdown structure is included. Approaches used in deriving SDLV costs, including calibration factors and historical data are described. Both SDLV cost estimates and SDLV/STS cost comparisons are summarized. Standard formats are used to report comprehensive SDLV life cycle estimates. Hardware cost estimates (below subsystem level) obtained using the RCA PRICE 84 cost model are included along with other supporting data.
ARTEMIS: a collaborative framework for health care.
Reddy, R.; Jagannathan, V.; Srinivas, K.; Karinthi, R.; Reddy, S. M.; Gollapudy, C.; Friedman, S.
1993-01-01
Patient centered healthcare delivery is an inherently collaborative process. This involves a wide range of individuals and organizations with diverse perspectives: primary care physicians, hospital administrators, labs, clinics, and insurance. The key to cost reduction and quality improvement in health care is effective management of this collaborative process. The use of multi-media collaboration technology can facilitate timely delivery of patient care and reduce cost at the same time. During the last five years, the Concurrent Engineering Research Center (CERC), under the sponsorship of DARPA (Defense Advanced Research Projects Agency, recently renamed ARPA) developed a number of generic key subsystems of a comprehensive collaboration environment. These subsystems are intended to overcome the barriers that inhibit the collaborative process. Three subsystems developed under this program include: MONET (Meeting On the Net)--to provide consultation over a computer network, ISS (Information Sharing Server)--to provide access to multi-media information, and PCB (Project Coordination Board)--to better coordinate focussed activities. These systems have been integrated into an open environment to enable collaborative processes. This environment is being used to create a wide-area (geographically distributed) research testbed under DARPA sponsorship, ARTEMIS (Advance Research Testbed for Medical Informatics) to explore the collaborative health care processes. We believe this technology will play a key role in the current national thrust to reengineer the present health-care delivery system. PMID:8130536
Using pyrosequencing to shed light on deep mine microbial ecology
Edwards, Robert A; Rodriguez-Brito, Beltran; Wegley, Linda; Haynes, Matthew; Breitbart, Mya; Peterson, Dean M; Saar, Martin O; Alexander, Scott; Alexander, E Calvin; Rohwer, Forest
2006-01-01
Background Contrasting biological, chemical and hydrogeological analyses highlights the fundamental processes that shape different environments. Generating and interpreting the biological sequence data was a costly and time-consuming process in defining an environment. Here we have used pyrosequencing, a rapid and relatively inexpensive sequencing technology, to generate environmental genome sequences from two sites in the Soudan Mine, Minnesota, USA. These sites were adjacent to each other, but differed significantly in chemistry and hydrogeology. Results Comparisons of the microbes and the subsystems identified in the two samples highlighted important differences in metabolic potential in each environment. The microbes were performing distinct biochemistry on the available substrates, and subsystems such as carbon utilization, iron acquisition mechanisms, nitrogen assimilation, and respiratory pathways separated the two communities. Although the correlation between much of the microbial metabolism occurring and the geochemical conditions from which the samples were isolated could be explained, the reason for the presence of many pathways in these environments remains to be determined. Despite being physically close, these two communities were markedly different from each other. In addition, the communities were also completely different from other microbial communities sequenced to date. Conclusion We anticipate that pyrosequencing will be widely used to sequence environmental samples because of the speed, cost, and technical advantages. Furthermore, subsystem comparisons rapidly identify the important metabolisms employed by the microbes in different environments. PMID:16549033
Cost decomposition of linear systems with application to model reduction
NASA Technical Reports Server (NTRS)
Skelton, R. E.
1980-01-01
A means is provided to assess the value or 'cst' of each component of a large scale system, when the total cost is a quadratic function. Such a 'cost decomposition' of the system has several important uses. When the components represent physical subsystems which can fail, the 'component cost' is useful in failure mode analysis. When the components represent mathematical equations which may be truncated, the 'component cost' becomes a criterion for model truncation. In this latter event component costs provide a mechanism by which the specific control objectives dictate which components should be retained in the model reduction process. This information can be valuable in model reduction and decentralized control problems.
Control Software for the VERITAS Cerenkov Telescope System
NASA Astrophysics Data System (ADS)
Krawczynski, H.; Olevitch, M.; Sembroski, G.; Gibbs, K.
2003-07-01
The VERITAS collab oration is developing a system of initially 4 and ˇ eventually 7 Cerenkov telescopes of the 12 m diameter class for high sensitivity gamma-ray astronomy in the >50 GeV energy range. In this contribution we describe the software that controls and monitors the various VERITAS subsystems. The software uses an object-oriented approach to cop e with the complexities that arise from using sub-groups of the 7 VERITAS telescopes to observe several sources at the same time. Inter-pro cess communication is based on the CORBA object Request Broker proto col and watch-dog processes monitor the sub-system performance.
Interdisciplinary and multilevel optimum design
NASA Technical Reports Server (NTRS)
Sobieszczanski-Sobieski, Jaroslaw; Haftka, Raphael T.
1986-01-01
Interactions among engineering disciplines and subsystems in engineering system design are surveyed and specific instances of such interactions are described. Examination of the interactions that a traditional design process in which the numerical values of major design variables are decided consecutively is likely to lead to a suboptimal design. Supporting numerical examples are a glider and a space antenna. Under an alternative approach introduced, the design and its sensitivity data from the subsystems and disciplines are generated concurrently and then made available to the system designer enabling him to modify the system design so as to improve its performance. Examples of a framework structure and an airliner wing illustrate that approach.
Sensitivity based coupling strengths in complex engineering systems
NASA Technical Reports Server (NTRS)
Bloebaum, C. L.; Sobieszczanski-Sobieski, J.
1993-01-01
The iterative design scheme necessary for complex engineering systems is generally time consuming and difficult to implement. Although a decomposition approach results in a more tractable problem, the inherent couplings make establishing the interdependencies of the various subsystems difficult. Another difficulty lies in identifying the most efficient order of execution for the subsystem analyses. The paper describes an approach for determining the dependencies that could be suspended during the system analysis with minimal accuracy losses, thereby reducing the system complexity. A new multidisciplinary testbed is presented, involving the interaction of structures, aerodynamics, and performance disciplines. Results are presented to demonstrate the effectiveness of the system reduction scheme.
NASA Astrophysics Data System (ADS)
Bell, Kevin D.; Dafesh, Philip A.; Hsu, L. A.; Tsuda, A. S.
1995-12-01
Current architectural and design trade techniques often carry unaffordable alternatives late into the decision process. Early decisions made during the concept exploration and development (CE&D) phase will drive the cost of a program more than any other phase of development; thus, designers must be able to assess both the performance and cost impacts of their early choices. The Space Based Infrared System (SBIRS) cost engineering model (CEM) described in this paper is an end-to-end process integrating engineering and cost expertise through commonly available spreadsheet software, allowing for concurrent design engineering and cost estimation to identify and balance system drives to reduce acquisition costs. The automated interconnectivity between subsystem models using spreadsheet software allows for the quick and consistent assessment of the system design impacts and relative cost impacts due to requirement changes. It is different from most CEM efforts attempted in the past as it incorporates more detailed spacecraft and sensor payload models, and has been applied to determine the cost drivers for an advanced infrared satellite system acquisition. The CEM is comprised of integrated detailed engineering and cost estimating relationships describing performance, design, and cost parameters. Detailed models have been developed to evaluate design parameters for the spacecraft bus and sensor; both step-starer and scanner sensor types incorporate models of focal plane array, optics, processing, thermal, communications, and mission performance. The current CEM effort has provided visibility to requirements, design, and cost drivers for system architects and decision makers to determine the configuration of an infrared satellite architecture that meets essential requirements cost effectively. In general, the methodology described in this paper consists of process building blocks that can be tailored to the needs of many applications. Descriptions of the spacecraft and payload subsystem models provide insight into The Aerospace Corporation expertise and scope of the SBIRS concept development effort.
Design, processing and testing of LSI arrays, hybrid microelectronics task
NASA Technical Reports Server (NTRS)
Himmel, R. P.; Stuhlbarg, S. M.; Ravetti, R. G.; Zulueta, P. J.; Rothrock, C. W.
1979-01-01
Mathematical cost models previously developed for hybrid microelectronic subsystems were refined and expanded. Rework terms related to substrate fabrication, nonrecurring developmental and manufacturing operations, and prototype production are included. Sample computer programs were written to demonstrate hybrid microelectric applications of these cost models. Computer programs were generated to calculate and analyze values for the total microelectronics costs. Large scale integrated (LST) chips utilizing tape chip carrier technology were studied. The feasibility of interconnecting arrays of LSU chips utilizing tape chip carrier and semiautomatic wire bonding technology was demonstrated.
1987-09-01
University, the United States Air Force, or the Department of JDefense. Accession For NTIS GRA&I DTIC TAB Uliannouncedj u s t i f i c a t i o n...114 VI vi W,7% WN T "Vyn An r % List of Tables Table Page 1. ALCs Operation and Maintenance Costs ....... 53 2...CSCS deals strictly with aircraft com- ponents and subsystems that have been designated reparable, which means they are economical to repair. As part
Low cost coherent demodulation for mobile satellite terminals
NASA Technical Reports Server (NTRS)
Dutta, Santanu; Henely, Steven J.
1993-01-01
This paper describes some low cost approaches to coherent BPSK demodulation for mobile satellite receivers. The specific application is an Inmarsat-C Land Mobile Earth Station (LMES), but the techniques are applicable to any PSK demodulator. The techniques discussed include combined sampling and quadrature downconversion with a single A/D and novel DSP algorithms for carrier acquisition offering both superior performance and economy of DSP resources. The DSP algorithms run at 5.7 MIPS, and the entire DSP subsystem, built with commercially available parts, costs under $60 at quantity-10,000.
Als, Heidelise; Butler, Samantha; Kosta, Sandra; McAnulty, Gloria
2014-01-01
The Assessment of Preterm Infants' Behavior (APIB) is a newborn neurobehavioral assessment appropriate for preterm, at risk, and full-term newborns, from birth to 1 month after expected due date. The APIB is based in ethological–evolutionary thought and focuses on the assessment of mutually interacting behavioral subsystems in simultaneous interaction with the environment. The subsystems of functioning assessed include the autonomic (respiration, digestion, color), motor (tone, movement, postures), state organization (range, robustness, transition patterns), attention (robustness, transitions), and self-regulation (effort, success) systems as well as the degree of facilitation required to support reorganization and subsystem balance. The environment is represented by a sequence of distal, proximal, tactile, and vestibular challenges, derived from the BNBAS. The APIB conceptualizes infant competence as the degree of differentiation of subsystem function and degree of modulation of subsystem balance at any stage in infant development. Infants are understood as actively seeking their next differentiation, while counting on good enough environments to assure progressing developmental competence. In the case of interference such as premature birth, the mismatch of expectation and actual experience causes misalignment, which may become developmentally costly. The assessment is a finely tuned dialogue between examiner and infant, which requires training, skill and self-knowledge. The APIB has well established inter-rater-reliability, concurrent and construct validity, and is clinically relevant for behavioral intervention and individually appropriate and supportive care. PMID:15856436
Transitioning from conceptual design to construction performance specification
NASA Astrophysics Data System (ADS)
Jeffers, Paul; Warner, Mark; Craig, Simon; Hubbard, Robert; Marshall, Heather
2012-09-01
On successful completion of a conceptual design review by a funding agency or customer, there is a transition phase before construction contracts can be placed. The nature of this transition phase depends on the Project's approach to construction and the particular subsystem being considered. There are generically two approaches; project retention of design authority and issuance of build to print contracts, or issuance of subsystem performance specifications with controlled interfaces. This paper relates to the latter where a proof of concept (conceptual or reference design) is translated into performance based sub-system specifications for competitive tender. This translation is not a straightforward process and there are a number of different issues to consider in the process. This paper deals with primarily the Telescope mount and Enclosure subsystems. The main subjects considered in this paper are: • Typical status of design at Conceptual Design Review compared with the desired status of Specifications and Interface Control Documents at Request for Quotation. • Options for capture and tracking of system requirements flow down from science / operating requirements and sub-system requirements, and functional requirements derived from reference design. • Requirements that may come specifically from the contracting approach. • Methods for effective use of reference design work without compromising a performance based specification. • Management of project team's expectation relating to design. • Effects on cost estimates from reference design to actual. This paper is based on experience and lessons learned through this process on both the VISTA and the ATST projects.
EOS MLS Lessons Learned: Design Ideas for Safer and Lower Cost Operations
NASA Technical Reports Server (NTRS)
Miller, Dominick
2012-01-01
The Earth Observing System (EOS) Microwave Limb Sounder (MLS) is a complex instrument with a front end computer and 32 subsystem computers. MLS is one of four instruments on NASA's EOS Aura spacecraft With almost 8 years in orbit, MLS has a few lessons learned which can be applied during the design phase of future instruments to effect better longevity, more robust operations and a significant cost benefit during operations phase.
RS-600 programmable controller: Solar heating and cooling
NASA Technical Reports Server (NTRS)
1978-01-01
Three identical microprocessor control subsystems were developed which can be used in heating, heating and cooling, and/or hot water systems for single family, multifamily, or commercial applications. The controller incorporates a low cost, highly reliable (all solid state) microprocessor which can be easily reprogrammed.
Developments in Nano-Satellite Structural Subsystem Design at NASA-GSFC
NASA Technical Reports Server (NTRS)
Rossoni, Peter; Panetta, Peter V.
1999-01-01
The NASA-GSFC Nano-satellite Technology Development Program will enable flying constellations of tens to hundreds of nano-satellites for future NASA Space and Earth Science missions. Advanced technology components must be developed to make these future spacecraft compact, lightweight, low-power, low-cost, and survivable to a radiation environment over a two-year mission lifetime. This paper describes the efforts underway to develop lightweight, low cost, and multi-functional structures, serviceable designs, and robust mechanisms. As designs shrink, the integration of various subsystems becomes a vital necessity. This paper also addresses structurally integrated electrical power, attitude control, and thermal systems. These innovations bring associated fabrication, integration, and test challenges. Candidate structural materials and processes are examined and the merits of each are discussed. Design and fabrication processes include flat stock composite construction, cast aluminum-beryllium alloy, and an injection molded fiber-reinforced plastic. A viable constellation deployment scenario is described as well as a Phase-A Nano-satellite Pathfinder study.
Liu, Derong; Wang, Ding; Li, Hongliang
2014-02-01
In this paper, using a neural-network-based online learning optimal control approach, a novel decentralized control strategy is developed to stabilize a class of continuous-time nonlinear interconnected large-scale systems. First, optimal controllers of the isolated subsystems are designed with cost functions reflecting the bounds of interconnections. Then, it is proven that the decentralized control strategy of the overall system can be established by adding appropriate feedback gains to the optimal control policies of the isolated subsystems. Next, an online policy iteration algorithm is presented to solve the Hamilton-Jacobi-Bellman equations related to the optimal control problem. Through constructing a set of critic neural networks, the cost functions can be obtained approximately, followed by the control policies. Furthermore, the dynamics of the estimation errors of the critic networks are verified to be uniformly and ultimately bounded. Finally, a simulation example is provided to illustrate the effectiveness of the present decentralized control scheme.
A Channelized 2nd IF/LO Downconverter for the E0S Microwave Limb Sounder
NASA Technical Reports Server (NTRS)
LaBelle, Remi C.
2003-01-01
The Earth Observing System (EOS) Microwave Limb Sounder (MLS) is scheduled for launch in 2004 on the EOS Aura spacecraft. The design, assembly and test of the flight 2nd Intermediate Frequency/ Local Oscillator (2nd IF/LO) subsystem for this instrument has been completed and is presented here. The 2nd IF/LO subsystem consists of 5 separate microwave assemblies, 1 for each of the 5 millimeter wave radiometer front ends, providing a total of 33 separate IF channels. Some key requirements of the subsystem are as follows: provide frequency multiplexing of overlapping or closely spaced 1st IF channels while maintaining low ripple in the passbands; generate 19 different 2nd LO frequencies, in the range of 4-20 GHz, with low phase noise and a placement resolution of 400 KHz; downconvert the 1st IF's to a common 2nd IF frequency centered at 900 MHz; minimize cost and schedule by using common designs for the 5 different assemblies wherever possible.
Solar heating and hot water system installed at office building, One Solar Place, Dallas, Texas
NASA Technical Reports Server (NTRS)
1980-01-01
A solar heating on cooling system is described which is designed to provide 87 percent of the space heating needs, 100 percent of the potable hot water needs and is sized for future absorption cooling. The collection subsystem consists of 28 solargenics, series 76, flat plate collectors with a total area of 1,596 square feet. The solar loop circulates an ethylene glyco water solution through the collectors into a hot water system exchanger. The water storage subsystem consists of a heat exchanger, two 2,300 gallon concrete hot water storage tanks with built in heat exchangers and a back-up electric boiler. The domestic hot water subsystem sends hot water to the 10,200 square feet floor area office building hot water water fixtures. The building cold water system provides make up to the solar loop, the heating loop, and the hot water concrete storage tanks. The design, construction, cost analysis, operation and maintenance of the solar system are described.
H∞ control for switched fuzzy systems via dynamic output feedback: Hybrid and switched approaches
NASA Astrophysics Data System (ADS)
Xiang, Weiming; Xiao, Jian; Iqbal, Muhammad Naveed
2013-06-01
Fuzzy T-S model has been proven to be a practical and effective way to deal with the analysis and synthesis problems for complex nonlinear systems. As for switched nonlinear system, describing its subsystems as fuzzy T-S models, namely switched fuzzy system, naturally is an alternative method to conventional control approaches. In this paper, the H∞ control problem for a class of switched fuzzy systems is addressed. Hybrid and switched design approaches are proposed with different availability of switching signal information at switching instant. The hybrid control strategy includes two parts: fuzzy controllers for subsystems and state updating controller at switching instant, and the switched control strategy contains the controllers for subsystems. It is demonstrated that the conservativeness is reduced by introducing the state updating behavior but its cost is an online prediction of switching signal. Numerical examples are given to illustrate the effectiveness of proposed approaches and compare the conservativeness of two approaches.
Yang, Xiong; He, Haibo
2018-05-26
In this paper, we develop a novel optimal control strategy for a class of uncertain nonlinear systems with unmatched interconnections. To begin with, we present a stabilizing feedback controller for the interconnected nonlinear systems by modifying an array of optimal control laws of auxiliary subsystems. We also prove that this feedback controller ensures a specified cost function to achieve optimality. Then, under the framework of adaptive critic designs, we use critic networks to solve the Hamilton-Jacobi-Bellman equations associated with auxiliary subsystem optimal control laws. The critic network weights are tuned through the gradient descent method combined with an additional stabilizing term. By using the newly established weight tuning rules, we no longer need the initial admissible control condition. In addition, we demonstrate that all signals in the closed-loop auxiliary subsystems are stable in the sense of uniform ultimate boundedness by using classic Lyapunov techniques. Finally, we provide an interconnected nonlinear plant to validate the present control scheme. Copyright © 2018 Elsevier Ltd. All rights reserved.
Slush Hydrogen Technology Program
NASA Technical Reports Server (NTRS)
Cady, Edwin C.
1994-01-01
A slush hydrogen (SH2) technology facility (STF) was designed, fabricated, and assembled by a contractor team of McDonnell Douglas Aerospace (MDA), Martin Marietta Aerospace Group (MMAG), and Air Products and Chemicals, Inc. (APCI). The STF consists of a slush generator which uses the freeze-thaw production process, a vacuum subsystem, a test tank which simulates the NASP vehicle, a triple point hydrogen receiver tank, a transfer subsystem, a sample bottle, a pressurization system, and a complete instrumentation and control subsystem. The STF was fabricated, checked-out, and made ready for testing under this contract. The actual SH2 testing was performed under the NASP consortium following NASP teaming. Pre-STF testing verified SH2 production methods, validated special SH2 instrumentation, and performed limited SH2 pressurization and expulsion tests which demonstrated the need for gaseous helium pre-pressurized of SH2 to control pressure collapse. The STF represents cutting-edge technology development by an effective Government-Industry team under very tight cost and schedule constraints.
NASA Astrophysics Data System (ADS)
Efstratiadis, Andreas; Nalbantis, Ioannis; Rozos, Evangelos; Koutsoyiannis, Demetris
2010-05-01
In mixed natural and artificialized river basins, many complexities arise due to anthropogenic interventions in the hydrological cycle, including abstractions from surface water bodies, groundwater pumping or recharge and water returns through drainage systems. Typical engineering approaches adopt a multi-stage modelling procedure, with the aim to handle the complexity of process interactions and the lack of measured abstractions. In such context, the entire hydrosystem is separated into natural and artificial sub-systems or components; the natural ones are modelled individually, and their predictions (i.e. hydrological fluxes) are transferred to the artificial components as inputs to a water management scheme. To account for the interactions between the various components, an iterative procedure is essential, whereby the outputs of the artificial sub-systems (i.e. abstractions) become inputs to the natural ones. However, this strategy suffers from multiple shortcomings, since it presupposes that pure natural sub-systems can be located and that sufficient information is available for each sub-system modelled, including suitable, i.e. "unmodified", data for calibrating the hydrological component. In addition, implementing such strategy is ineffective when the entire scheme runs in stochastic simulation mode. To cope with the above drawbacks, we developed a generalized modelling framework, following a network optimization approach. This originates from the graph theory, which has been successfully implemented within some advanced computer packages for water resource systems analysis. The user formulates a unified system which is comprised of the hydrographical network and the typical components of a water management network (aqueducts, pumps, junctions, demand nodes etc.). Input data for the later include hydraulic properties, constraints, targets, priorities and operation costs. The real-world system is described through a conceptual graph, whose dummy properties are the conveyance capacity and the unit cost of each link. Unit costs are either real or artificial, and positive or negative. Positive costs are set to prohibit undesirable fluxes and negative ones to force fulfilling water demands for various uses. The assignment of costs is based on a recursive algorithm that implements the physical constraints and the user-specified hierarchy for the water uses. Referring to the desired management policy, an optimal allocation is achieved regarding the unknown fluxes within the hydrosystem (flows, abstractions, water losses) by minimizing the total transportation cost through the graph. The mathematical structure of the problem enables use of accurate and exceptionally fast solvers. The proposed methodology is effective, efficient and easy to implement, in order to link on-line multiple modelling components, thus ensuring a comprehensive overview of the process interactions in complex and heavily modified hydrosystems. It is applicable to hydrological simulators of the semi-distributed type, in which it allows integrating groundwater models and flood routing schemes within decision support modules. The methodology is implemented within the HYGROGEIOS computer package, which is illustrated by example applications in modified river basins in Greece.
Optimization of life support systems and their systems reliability
NASA Technical Reports Server (NTRS)
Fan, L. T.; Hwang, C. L.; Erickson, L. E.
1971-01-01
The identification, analysis, and optimization of life support systems and subsystems have been investigated. For each system or subsystem that has been considered, the procedure involves the establishment of a set of system equations (or mathematical model) based on theory and experimental evidences; the analysis and simulation of the model; the optimization of the operation, control, and reliability; analysis of sensitivity of the system based on the model; and, if possible, experimental verification of the theoretical and computational results. Research activities include: (1) modeling of air flow in a confined space; (2) review of several different gas-liquid contactors utilizing centrifugal force: (3) review of carbon dioxide reduction contactors in space vehicles and other enclosed structures: (4) application of modern optimal control theory to environmental control of confined spaces; (5) optimal control of class of nonlinear diffusional distributed parameter systems: (6) optimization of system reliability of life support systems and sub-systems: (7) modeling, simulation and optimal control of the human thermal system: and (8) analysis and optimization of the water-vapor eletrolysis cell.
NASA Technical Reports Server (NTRS)
Rader, W. P.; Barrett, S.; Raratono, J.; Payne, K. R.
1976-01-01
The current predicted acoustic environment for the shuttle orbiter payload bay will produce random vibration environments for payload components and subsystems which potentially will result in design, weight and cost penalties if means of protecting the payloads are not developed. Results are presented of a study to develop, through design and cost effectiveness trade studies, conceptual noise suppression device designs for space shuttle payloads. The impact of noise suppression on environmental levels and associated test costs, and on test philosophy for the various payload classes is considered with the ultimate goal of reducing payload test costs. Conclusions and recommendations are presented.
Improved E-ELT subsystem and component specifications, thanks to M1 test facility
NASA Astrophysics Data System (ADS)
Dimmler, M.; Marrero, J.; Leveque, S.; Barriga, Pablo; Sedghi, B.; Kornweibel, N.
2014-07-01
During the last 2 years ESO has operated the "M1 Test Facility", a test stand consisting of a representative section of the E-ELT primary mirror equipped with 4 complete prototype segment subunits including sensors, actuators and control system. The purpose of the test facility is twofold: it serves to study and get familiar with component and system aspects like calibration, alignment and handling procedures and suitable control strategies on real hardware long before the primary mirror (hereafter M1) components are commissioned. Secondly, and of major benefit to the project, it offered the possibility to evaluate component and subsystem performance and interface issues in a system context in such detail, that issues could be identified early enough to feed back into the subsystem and component specifications. This considerably reduces risk and cost of the production units and allows refocusing the project team on important issues for the follow-up of the production contracts. Experiences are presented in which areas the results of the M1 Test Facility particularly helped to improve subsystem specifications and areas, where additional tests were adopted independent of the main test facility. Presented are the key experiences of the M1 Test Facility which lead to improved specifications or identified the need for additional testing outside of the M1 Test Facility.
NASA Technical Reports Server (NTRS)
Perry, Jay L.; Abney, Morgan B.; Knox, James C.; Parrish, Keith J.; Roman, Monserrate C.; Jan, Darrell L.
2012-01-01
Exploring the frontiers of deep space continues to be defined by the technological challenges presented by safely transporting a crew to and from destinations of scientific interest. Living and working on that frontier requires highly reliable and efficient life support systems that employ robust, proven process technologies. The International Space Station (ISS), including its environmental control and life support (ECLS) system, is the platform from which humanity's deep space exploration missions begin. The ISS ECLS system Atmosphere Revitalization (AR) subsystem and environmental monitoring (EM) technical architecture aboard the ISS is evaluated as the starting basis for a developmental effort being conducted by the National Aeronautics and Space Administration (NASA) via the Advanced Exploration Systems (AES) Atmosphere Resource Recovery and Environmental Monitoring (ARREM) Project.. An evolutionary approach is employed by the ARREM project to address the strengths and weaknesses of the ISS AR subsystem and EM equipment, core technologies, and operational approaches to reduce developmental risk, improve functional reliability, and lower lifecycle costs of an ISS-derived subsystem architecture suitable for use for crewed deep space exploration missions. The most promising technical approaches to an ISS-derived subsystem design architecture that incorporates promising core process technology upgrades will be matured through a series of integrated tests and architectural trade studies encompassing expected exploration mission requirements and constraints.
Implementation of Integrated System Fault Management Capability
NASA Technical Reports Server (NTRS)
Figueroa, Fernando; Schmalzel, John; Morris, Jon; Smith, Harvey; Turowski, Mark
2008-01-01
Fault Management to support rocket engine test mission with highly reliable and accurate measurements; while improving availability and lifecycle costs. CORE ELEMENTS: Architecture, taxonomy, and ontology (ATO) for DIaK management. Intelligent Sensor Processes; Intelligent Element Processes; Intelligent Controllers; Intelligent Subsystem Processes; Intelligent System Processes; Intelligent Component Processes.
Development and fabrication of a solar cell junction processing system
NASA Technical Reports Server (NTRS)
Banker, S.
1982-01-01
Development of a pulsed electron beam subsystem, wafer transport system, and ion implanter are discussed. A junction processing system integration and cost analysis are reviewed. Maintenance of the electron beam processor and the experimental test unit of the non-mass analyzed ion implanter is reviewed.
Quantitative software models for the estimation of cost, size, and defects
NASA Technical Reports Server (NTRS)
Hihn, J.; Bright, L.; Decker, B.; Lum, K.; Mikulski, C.; Powell, J.
2002-01-01
The presentation will provide a brief overview of the SQI measurement program as well as describe each of these models and how they are currently being used in supporting JPL project, task and software managers to estimate and plan future software systems and subsystems.
NASA Technical Reports Server (NTRS)
1974-01-01
A listing of the Earth Observatory Satellite (EOS) candidate missions is presented for use as a baseline in describing the EOS payloads. The missions are identified in terms of first, second, and third generation payloads. The specific applications of the EOS satellites are defined. The subjects considered are: (1) orbit analysis, (2) space shuttle interfaces, (3) thematic mapping subsystem, (4) high resolution pointable imager subsystem, (5) the data collection system, (6) the synthetic aperture radar, (7) the passive multichannel microwave radiometer, and (8) the wideband communications and handling equipment. Illustrations of the satellite and launch vehicle configurations are provided. Block diagrams of the electronic circuits are included.
Technical and economic feasibility study of solar/fossil hybrid power systems
NASA Technical Reports Server (NTRS)
Bloomfield, H. S.; Calogeras, J. E.
1977-01-01
Results show that new hybrid systems utilizing fossil fuel augmentation of solar energy can provide significant capital and energy cost benefits when compared with solar thermal systems requiring thermal storage. These benefits accrue from a reduction of solar collection area that results from both the use of highly efficient gas and combined cycle energy conversion subsystems and elimination of the requirement for long-term energy storage subsystems. Technical feasibility and fuel savings benefits of solar hybrid retrofit to existing fossil-fired, gas and vapor cycle powerplants was confirmed; however, economic viability of steam cycle retrofit was found to be dependent on the thermodynamic and operational characteristics of the existing powerplant.
An atmosphere protection subsystem in the thermal power station automated process control system
NASA Astrophysics Data System (ADS)
Parchevskii, V. M.; Kislov, E. A.
2014-03-01
Matters concerned with development of methodical and mathematical support for an atmosphere protection subsystem in the thermal power station automated process control system are considered taking as an example the problem of controlling nitrogen oxide emissions at a gas-and-oil-fired thermal power station. The combined environmental-and-economic characteristics of boilers, which correlate the costs for suppressing emissions with the boiler steam load and mass discharge of nitrogen oxides in analytic form, are used as the main tool for optimal control. A procedure for constructing and applying environmental-and-economic characteristics on the basis of technical facilities available in modern instrumentation and control systems is presented.
The importance of operations, risk, and cost assessment to space transfer systems design
NASA Technical Reports Server (NTRS)
Ball, J. M.; Komerska, R. J.; Rowell, L. F.
1992-01-01
This paper examines several methodologies which contribute to comprehensive subsystem cost estimation. The example of a space-based lunar space transfer vehicle (STV) design is used to illustrate how including both primary and secondary factors into cost affects the decision of whether to use aerobraking or propulsion for earth orbit capture upon lunar return. The expected dominant cost factor in this decision is earth-to-orbit launch cost driven by STV mass. However, to quantify other significant cost factors, this cost comparison included a risk analysis to identify development and testing costs, a Taguchi design of experiments to determine a minimum mass aerobrake design, and a detailed operations analysis. As a result, the predicted cost advantage of aerobraking, while still positive, was subsequently reduced by about 30 percent compared to the simpler mass-based cost estimates.
Separate valuation subsystems for delay and effort decision costs.
Prévost, Charlotte; Pessiglione, Mathias; Météreau, Elise; Cléry-Melin, Marie-Laure; Dreher, Jean-Claude
2010-10-20
Decision making consists of choosing among available options on the basis of a valuation of their potential costs and benefits. Most theoretical models of decision making in behavioral economics, psychology, and computer science propose that the desirability of outcomes expected from alternative options can be quantified by utility functions. These utility functions allow a decision maker to assign subjective values to each option under consideration by weighting the likely benefits and costs resulting from an action and to select the one with the highest subjective value. Here, we used model-based neuroimaging to test whether the human brain uses separate valuation systems for rewards (erotic stimuli) associated with different types of costs, namely, delay and effort. We show that humans devalue rewards associated with physical effort in a strikingly similar fashion to those they devalue that are associated with delays, and that a single computational model derived from economics theory can account for the behavior observed in both delay discounting and effort discounting. However, our neuroimaging data reveal that the human brain uses distinct valuation subsystems for different types of costs, reflecting in opposite fashion delayed reward and future energetic expenses. The ventral striatum and the ventromedial prefrontal cortex represent the increasing subjective value of delayed rewards, whereas a distinct network, composed of the anterior cingulate cortex and the anterior insula, represent the decreasing value of the effortful option, coding the expected expense of energy. Together, these data demonstrate that the valuation processes underlying different types of costs can be fractionated at the cerebral level.
Kramer, Sam L; Rodriguez, Benjamin F
2018-07-01
Evidence suggests that the behavior inhibition system (BIS) and fight-flight-freeze system play a role in the individual differences seen in social anxiety disorder; however, findings concerning the role of the behavior approach system (BAS) have been mixed. To date, the role of revised reinforcement sensitivity theory (RST) subsystems underlying social anxiety has been measured with scales designed for the original RST. This study examined how the BIS, BAS, and fight, flight, freeze components of the fight-flight-freeze system uniquely relate to social interaction anxiety and social observation anxiety using both a measure specifically designed for the revised RST and a commonly used original RST measure. Comparison of regression analyses with the Jackson-5 and the commonly used BIS/BAS Scales revealed important differences in the relationships between RST subsystems and social anxiety depending on how RST was assessed. Limitations and future directions for revised RST measurement are discussed.
A Holistic Approach to Systems Development
NASA Technical Reports Server (NTRS)
Wong, Douglas T.
2008-01-01
Introduces a Holistic and Iterative Design Process. Continuous process but can be loosely divided into four stages. More effort spent early on in the design. Human-centered and Multidisciplinary. Emphasis on Life-Cycle Cost. Extensive use of modeling, simulation, mockups, human subjects, and proven technologies. Human-centered design doesn t mean the human factors discipline is the most important Disciplines should be involved in the design: Subsystem vendors, configuration management, operations research, manufacturing engineering, simulation/modeling, cost engineering, hardware engineering, software engineering, test and evaluation, human factors, electromagnetic compatibility, integrated logistics support, reliability/maintainability/availability, safety engineering, test equipment, training systems, design-to-cost, life cycle cost, application engineering etc. 9
NASA Technical Reports Server (NTRS)
Gutmann, R. J.; Borrego, J. M.
1978-01-01
Rectenna conversion efficiencies (RF to dc) approximating 85 percent were demonstrated on a small scale, clearly indicating the feasibility and potential of efficiency of microwave power to dc. The overall cost estimates of the solar power satellite indicate that the baseline rectenna subsystem will be between 25 to 40 percent of the system cost. The directional receiving elements and element extensions were studied, along with power combining evaluation and evaluation extensions.
Defense Communications Agency Cost and Planning Factors Manual. Change 2.
1985-09-23
5 39-6 40. FISCAL -YEAR TIME PHASING OF COST ESTIMATE ...... 40-1 (To be published later) 41. DISCOUNTING General...cubic foot (feet) ft3 /min cubic foot (feet) per minute FY fiscal year FYDP Five Year Defense Program FYP Five Year Program G&A general & administrative... fiscal year 1 of the subsystem project plan. The remainder of the equipment and buildings and the training are to be contracted for and the system turned
Ultra-low-cost clinical pulse oximetry.
Petersen, Christian L; Gan, Heng; MacInnis, Martin J; Dumont, Guy A; Ansermino, J Mark
2013-01-01
An ultra-low-cost pulse oximeter is presented that interfaces a conventional clinical finger sensor with a mobile phone through the headset jack audio interface. All signal processing is performed using the audio subsystem of the phone. In a preliminary volunteer study in a hypoxia chamber, we compared the oxygen saturation obtained with the audio pulse oximeter against a commercially available (and FDA approved) reference pulse oximeter (Nonin Xpod). Good agreement was found between the outputs of the two devices.
An Analytical Calibration Approach for the Polarimetric Airborne C Band Radiometer
NASA Technical Reports Server (NTRS)
Pham, Hanh; Kim, Edward J.
2004-01-01
Passive microwave remote sensing is sensitive to the quantity and distribution of water in soil and vegetation. During summer 2000, the Microwave Geophysics Group at the University of Michigan conducted the 7th Radiobrightness Energy Balance Experiment (REBEX-7) over a corn canopy in Michigan. Long time series of brightness temperatures, soil moisture and micrometeorology on the plot scale were taken. This paper addresses the calibration of the NASA GSFC polarimetric airborne C band microwave radiometer (ACMR) that participated in REBEX-7. Passive polarimeters are typically calibrated using an end-to-end approach based upon a standard artificial target or a well-known geophysical target. Analyzing the major internal functional subsystems offers a different perspective. The primary goal of this approach is to provide a transfer function that not only describes the system in its entirety but also accounts for the contributions of each subsystem toward the final modified Stokes parameters. This approach also serves as a realistic instrument simulator, a useful tool for future designs. The ACMR architecture can be partitioned into several functional subsystems. Each subsystem was extensively measured and the estimated parameters were imported into the overall system model. We will present the results of polarimetric antenna measurements, the instrument model as well as four Stokes observations from REBEX-7 using a first order inversion.
Interdisciplinary and multilevel optimum design. [in aerospace structural engineering
NASA Technical Reports Server (NTRS)
Sobieszczanski-Sobieski, Jaroslaw; Haftka, Raphael T.
1987-01-01
Interactions among engineering disciplines and subsystems in engineering system design are surveyed and specific instances of such interactions are described. Examination of the interactions that a traditional design process in which the numerical values of major design variables are decided consecutively is likely to lead to a suboptimal design. Supporting numerical examples are a glider and a space antenna. Under an alternative approach introduced, the design and its sensitivity data from the subsystems and disciplines are generated concurrently and then made available to the system designer enabling him to modify the system design so as to improve its performance. Examples of a framework structure and an airliner wing illustrate that approach.
Turbofan Engine Core Compartment Vent Aerodynamic Configuration Development Methodology
NASA Technical Reports Server (NTRS)
Hebert, Leonard J.
2006-01-01
This paper presents an overview of the design methodology used in the development of the aerodynamic configuration of the nacelle core compartment vent for a typical Boeing commercial airplane together with design challenges for future design efforts. Core compartment vents exhaust engine subsystem flows from the space contained between the engine case and the nacelle of an airplane propulsion system. These subsystem flows typically consist of precooler, oil cooler, turbine case cooling, compartment cooling and nacelle leakage air. The design of core compartment vents is challenging due to stringent design requirements, mass flow sensitivity of the system to small changes in vent exit pressure ratio, and the need to maximize overall exhaust system performance at cruise conditions.
Shuttle cryogenic supply system optimization study
NASA Technical Reports Server (NTRS)
1971-01-01
Technical information on different cryogenic supply systems is presented for selecting representative designs. Parametric data and sensitivity studies, and an evaluation of related technology status are included. An integrated mathematical model for hardware program support was developed. The life support system, power generation, and propellant supply are considered. The major study conclusions are the following: Optimum integrated systems tend towards maximizing liquid storage. Vacuum jacketing of tanks is a major effect on integrated systems. Subcritical storage advantages over supercritical storage decrease as the quantity of propellant or reactant decreases. Shuttle duty cycles are not severe. The operational mode has a significant effect on reliability. Components are available for most subsystem applications. Subsystems and components require a minimum amount of technology development.
Latest NASA Instrument Cost Model (NICM): Version VI
NASA Technical Reports Server (NTRS)
Mrozinski, Joe; Habib-Agahi, Hamid; Fox, George; Ball, Gary
2014-01-01
The NASA Instrument Cost Model, NICM, is a suite of tools which allow for probabilistic cost estimation of NASA's space-flight instruments at both the system and subsystem level. NICM also includes the ability to perform cost by analogy as well as joint confidence level (JCL) analysis. The latest version of NICM, Version VI, was released in Spring 2014. This paper will focus on the new features released with NICM VI, which include: 1) The NICM-E cost estimating relationship, which is applicable for instruments flying on Explorer-like class missions; 2) The new cluster analysis ability which, alongside the results of the parametric cost estimation for the user's instrument, also provides a visualization of the user's instrument's similarity to previously flown instruments; and 3) includes new cost estimating relationships for in-situ instruments.
Statistical Analysis of Complexity Generators for Cost Estimation
NASA Technical Reports Server (NTRS)
Rowell, Ginger Holmes
1999-01-01
Predicting the cost of cutting edge new technologies involved with spacecraft hardware can be quite complicated. A new feature of the NASA Air Force Cost Model (NAFCOM), called the Complexity Generator, is being developed to model the complexity factors that drive the cost of space hardware. This parametric approach is also designed to account for the differences in cost, based on factors that are unique to each system and subsystem. The cost driver categories included in this model are weight, inheritance from previous missions, technical complexity, and management factors. This paper explains the Complexity Generator framework, the statistical methods used to select the best model within this framework, and the procedures used to find the region of predictability and the prediction intervals for the cost of a mission.
A Conceptual Framework for Institutional Research in Community Colleges.
ERIC Educational Resources Information Center
Alfred, Richard L.; Ivens, Stephen H.
This paper defines a conceptual model for institutional research in the community college and identifies sources of information, programs, and services that provide data necessary for implementation of the model. The model contains four specific subsystems: goal setting, program development, program review, and cost effectiveness. Each subsystem…
A fault tolerant spacecraft supercomputer to enable a new class of scientific discovery
NASA Technical Reports Server (NTRS)
Katz, D. S.; McVittie, T. I.; Silliman, A. G., Jr.
2000-01-01
The goal of the Remote Exploration and Experimentation (REE) Project is to move supercomputeing into space in a coste effective manner and to allow the use of inexpensive, state of the art, commercial-off-the-shelf components and subsystems in these space-based supercomputers.
NASA Technical Reports Server (NTRS)
Coan, Mary R.; Stewart, Elaine M.
2015-01-01
The Regolith and Environment Science & Oxygen and Lunar Volatile Extraction (RESOLVE) payload is part of Resource Prospector (RP) along with a rover and a lander that are expected to launch in 2020. RP will identify volatile elements that may be combined and collected to be used for fuel, air, and water in order to enable deeper space exploration. The Resource Prospector mission is a key part of In-Situ Resource Utilization (ISRU). The demand for this method of utilizing resources at the site of exploration is increasing due to the cost of resupply missions and deep space exploration goals. The RESOLVE payload includes the Lunar Advanced Volatile Analysis (LAVA) subsystem. The main instrument used to identify the volatiles evolved from the lunar regolith is the Gas Chromatograph-Mass Spectrometer (GC-MS). LAVA analyzes the volatiles emitted from the Oxygen and Volatile Extraction Node (OVEN) Subsystem. The objective of OVEN is to obtain, weigh, heat and transfer evolved gases to LAVA through the connection between the two subsystems called the LOVEN line. This paper highlights the work completed during a ten week internship that involved the integration, testing, data analysis, and procedure documentation of two candidate mass spectrometers for the LAVA subsystem in order to aid in determining which model to use for flight. Additionally, the examination of data from the integrated Resource Prospector '15 (RP' 15) field test will be presented in order to characterize the amount of water detected from water doped regolith samples.
Point Focusing Thermal and Electric Applications Project. Volume 2: Workshop proceedings
NASA Technical Reports Server (NTRS)
Landis, K. E. (Editor)
1979-01-01
Point focus distributed receiver solar thermal technology for the production of electric power and of industrial process heat is discussed. Thermal power systems are described. Emphasis is on the development of cost effective systems which will accelerate the commercialization and industrialization of plants, using parabolic dish collectors. The characteristics of PFDR systems and the cost targets for major subsystems hardware are identified. Markets for this technology and their size are identified, and expected levelized bus bar energy costs as a function of yearly production level are presented. The present status of the technology development effort is discussed.
An advanced communications synthesizer
NASA Astrophysics Data System (ADS)
Scherer, Ernst F.
1994-02-01
With the proliferation of smaller and lower cost EHF terminals, the fast-hopping microwave synthesizer subsystem is rapidly becoming the limiting factor for further size and cost reduction. A new approach, based on a high-speed direct digital synthesizer (DDS) and a very fast voltage controlled oscillator (VCO) tracking loop, has yielded a highly integrable design with true low-cost potential. A frequency range of 1 to 20 GHz can be covered by a simple substitution of the VCO module. This advanced synthesizer realization promises a generic solution to a large class of synthesizer requirements, greatly facilitating standardization and promoting modular system concepts.
Molnár, Sándor; López, Inmaculada; Gámez, Manuel; Garay, József
2016-03-01
The paper is aimed at a methodological development in biological pest control. The considered one pest two-agent system is modelled as a verticum-type system. Originally, linear verticum-type systems were introduced by one of the authors for modelling certain industrial systems. These systems are hierarchically composed of linear subsystems such that a part of the state variables of each subsystem affect the dynamics of the next subsystem. Recently, verticum-type system models have been applied to population ecology as well, which required the extension of the concept a verticum-type system to the nonlinear case. In the present paper the general concepts and technics of nonlinear verticum-type control systems are used to obtain biological control strategies in a two-agent system. For the illustration of this verticum-type control, these tools of mathematical systems theory are applied to a dynamic model of interactions between the egg and larvae populations of the sugarcane borer (Diatraea saccharalis) and its parasitoids: the egg parasitoid Trichogramma galloi and the larvae parasitoid Cotesia flavipes. In this application a key role is played by the concept of controllability, which means that it is possible to steer the system to an equilibrium in given time. In addition to a usual linearization, the basic idea is a decomposition of the control of the whole system into the control of the subsystems, making use of the verticum structure of the population system. The main aim of this study is to show several advantages of the verticum (or decomposition) approach over the classical control theoretical model (without decomposition). For example, in the case of verticum control the pest larval density decreases below the critical threshold value much quicker than without decomposition. Furthermore, it is also shown that the verticum approach may be better even in terms of cost effectiveness. The presented optimal control methodology also turned out to be an efficient tool for the "in silico" analysis of the cost-effectiveness of different biocontrol strategies, e.g. by answering the question how far it is cost-effective to speed up the reduction of the pest larvae density, or along which trajectory this reduction should be carried out. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
NASA Instrument Cost/Schedule Model
NASA Technical Reports Server (NTRS)
Habib-Agahi, Hamid; Mrozinski, Joe; Fox, George
2011-01-01
NASA's Office of Independent Program and Cost Evaluation (IPCE) has established a number of initiatives to improve its cost and schedule estimating capabilities. 12One of these initiatives has resulted in the JPL developed NASA Instrument Cost Model. NICM is a cost and schedule estimator that contains: A system level cost estimation tool; a subsystem level cost estimation tool; a database of cost and technical parameters of over 140 previously flown remote sensing and in-situ instruments; a schedule estimator; a set of rules to estimate cost and schedule by life cycle phases (B/C/D); and a novel tool for developing joint probability distributions for cost and schedule risk (Joint Confidence Level (JCL)). This paper describes the development and use of NICM, including the data normalization processes, data mining methods (cluster analysis, principal components analysis, regression analysis and bootstrap cross validation), the estimating equations themselves and a demonstration of the NICM tool suite.
1984-09-01
subsystems including labor reporting, Prime BEEF (Base Engineer Emergency Forces) composition, work order control, material control, cost accounting...AirComan IL ARCE BallsticLangey AB,24 Misl Supr)-FC Norton AF CA ( Estr Region) - AFRCE (United Kingdom) Ruislip AB UK UntdSae0i Fre nErp * Ramstein AB...Air Force personnel and minimize information burden on users, providers, and handlers, thereby reducing the costs, labor and intensiveness, and time
Concept for a power system controller for large space electrical power systems
NASA Technical Reports Server (NTRS)
Lollar, L. F.; Lanier, J. R., Jr.; Graves, J. R.
1981-01-01
The development of technology for a fail-operatonal power system controller (PSC) utilizing microprocessor technology for managing the distribution and power processor subsystems of a large multi-kW space electrical power system is discussed. The specific functions which must be performed by the PSC, the best microprocessor available to do the job, and the feasibility, cost savings, and applications of a PSC were determined. A limited function breadboard version of a PSC was developed to demonstrate the concept and potential cost savings.
Quality Function Deployment for Large Systems
NASA Technical Reports Server (NTRS)
Dean, Edwin B.
1992-01-01
Quality Function Deployment (QFD) is typically applied to small subsystems. This paper describes efforts to extend QFD to large scale systems. It links QFD to the system engineering process, the concurrent engineering process, the robust design process, and the costing process. The effect is to generate a tightly linked project management process of high dimensionality which flushes out issues early to provide a high quality, low cost, and, hence, competitive product. A pre-QFD matrix linking customers to customer desires is described.
NASA Technical Reports Server (NTRS)
1977-01-01
The development of a framework and structure for shuttle era unmanned spacecraft projects and the development of a commonality evaluation model is documented. The methodology developed for model utilization in performing cost trades and comparative evaluations for commonality studies is discussed. The model framework consists of categories of activities associated with the spacecraft system's development process. The model structure describes the physical elements to be treated as separate identifiable entities. Cost estimating relationships for subsystem and program-level components were calculated.
Mars Pathfinder Microrover- Implementing a Low Cost Planetary Mission Experiment
NASA Technical Reports Server (NTRS)
Matijevic, J.
1996-01-01
The Mars Pathfinder Microrover Flight Experiment (MFEX) is a NASA Office of Space Access and Technology (OSAT) flight experiment which has been delivered and integrated with the Mars Pathfinder (MPF) lander and spacecraft system. The total cost of the MFEX mission, including all subsystem design and development, test, integration with the MPF lander and operations on Mars has been capped at $25 M??is paper discusses the process and the implementation scheme which has resulted in the development of this first Mars rover.
Jungblut, Lucas David; Reiss, John O; Paz, Dante A; Pozzi, Andrea G
2017-09-01
The anuran peripheral olfactory system is composed of a number of subsystems, represented by distinct neuroepithelia. These include the main olfactory epithelium and vomeronasal organ (found in most tetrapods) and three specialized epithelia of anurans: the buccal-exposed olfactory epithelium of larvae, and the olfactory recess and middle chamber epithelium of postmetamorphic animals. To better characterize the developmental changes in these subsystems across the life cycle, morphometric changes of the nasal chemosensory organs during larval development and metamorphosis were analyzed in three different anuran species (Rhinella arenarum, Hypsiboas pulchellus, and Xenopus laevis). We calculated the volume of the nasal chemosensory organs by measuring the neuroepithelial area from serial histological sections at four different stages. In larvae, the vomeronasal organ was relatively reduced in R. arenarum compared with the other two species; the buccal-exposed olfactory epithelium was absent in X. laevis, and best developed in H. pulchellus. In postmetamorphic animals, the olfactory epithelium (air-sensitive organ) was relatively bigger in terrestrial species (R. arenarum and H. pulchellus), whereas the vomeronasal and the middle chamber epithelia (water-sensitive organs) was best developed in X. laevis. A small olfactory recess (likely homologous with the middle chamber epithelium) was found in R. arenarum juveniles, but not in H. pulchellus. These results support the association of the vomeronasal and middle chamber epithelia with aquatic olfaction, as seen by their enhanced development in the secondarily aquatic juveniles of X. laevis. They also support a role for the larval buccal-exposed olfactory epithelium in assessment of oral contents: it was absent in X. laevis, an obligate suspension feeder, while present in the two grazing species. These initial quantitative results give, for the first time, insight into the functional importance of the peripheral olfactory subsystems across the anuran life cycle. © 2017 Wiley Periodicals, Inc.
Evaluation of solar electric propulsion technologies for discovery class missions
NASA Technical Reports Server (NTRS)
Oh, David Y.
2005-01-01
A detailed study examines the potential benefits that advanced electric propulsion (EP) technologies offer to the cost-capped missions in NASA's Discovery program. The study looks at potential cost and performance benefits provided by three EP technologies that are currently in development: NASA's Evolutionary Xenon Thruster (NEXT), an Enhanced NSTAR system, and a Low Power Hall effect thruster. These systems are analyzed on three straw man Discovery class missions and their performance is compared to a state of the art system using the NSTAR ion thruster. An electric propulsion subsystem cost model is used to conduct a cost-benefit analysis for each option. The results show that each proposed technology offers a different degree of performance and/or cost benefit for Discovery class missions.
Testing solar panels for small-size satellites: the UPMSAT-2 mission
NASA Astrophysics Data System (ADS)
Roibás-Millán, E.; Alonso-Moragón, A.; Jiménez-Mateos, A. G.; Pindado, S.
2017-11-01
At present, the development of small-size satellites by universities, companies and research institutions has become usual practice, and is spreading rapidly. In this kind of project cost plays a significant role. One of the main areas are the assembly, integration and test (AIT) plans, which carry an associated cost for simulating environmental conditions. For instance, in the power subsystems test and, in particular, in the testing of solar panels, the irradiance and temperature conditions might be optimum so the performance of the system can be shown next to real operational conditions. To reproduce the environmental conditions in terms of irradiance, solar simulators are usually used, which carries an associated increase in cost for testing the equipment. The aim of this paper is to present an alternative and inexpensive way to perform AIT plans on spacecraft power subsystems, from a testing campaign performed using outdoor clean-sky conditions and an isolation system to protect the panels. A post-process of the measured data is therefore needed, taking into account the conditions in which the test has been accomplished. The I-V characteristics obtained are compared with a theoretical 1-diode/2-resistor equivalent electric circuit, achieving enough precision based solely on the manufacturer’s data.
Propellant Feed Subsystem for the X-34 Main Propulsion System
NASA Technical Reports Server (NTRS)
McDonald, J. P.; Minor, R. B.; Knight, K. C.; Champion, R. H., Jr.; Russell, F. J., Jr.
1998-01-01
The Orbital Sciences Corporation X-34 vehicle demonstrates technologies and operations key to future reusable launch vehicles. The general flight performance goal of this unmanned rocket plane is Mach 8 flight at an altitude of 250,000 feet. The Main Propulsion System supplies liquid propellants to the main engine, which provides the primary thrust for attaining mission goals. Major NMS design and operational goals are aircraft-like ground operations, quick turnaround between missions, and low initial/operational costs. This paper reviews major design and analysis aspects of the X-34 propellant feed subsystem of the X-34 Main Propulsion System. Topics include system requirements, system design, the integration of flight and feed system performance, propellant acquisition at engine start, and propellant tank terminal drain.
NASA Technical Reports Server (NTRS)
1983-01-01
The overall configuration and modules of the initial and evolved space station are described as well as tended industrial and polar platforms. The mass properties that are the basis for costing are summarized. User friendly attributes (interfaces, resources, and facilities) are identified for commercial; science and applications; industrial park; international participation; national security; and the external tank option. Configuration alternates studied to determine a baseline are examined. Commonality for clustered 3-man and 9-man stations are considered as well as the use of tethered platforms. Requirements are indicated for electrical, communication and tracking; data management Subsystem requirements for electrical, data management, communication and tracking, environment control/life support system; and guidance navigation and control subsystems are identified.
NASA Technical Reports Server (NTRS)
1972-01-01
The modular space station comprising small, shuttle-launched modules, and characterized by low initial cost and incremental manning, is described. The initial space station is designed to be delivered into orbit by three space shuttles and assembled in space. The three sections are the power/subsystems module, the crew/operations module, and the general purpose laboratory module. It provides for a crew of six. Subsequently duplicate/crew/operations and power/subsystems modules will be mated to the original modules, and provide for an additional six crewmen. A total of 17 research and applications modules is planned, three of which will be free-flying modules. Details are given on the program plan, modular characteristics, logistics, experiment support capability and requirements, operations analysis, design support analyses, and shuttle interfaces.
Space Transportation System (STS) propellant scavenging system study. Volume 1: Technical report
NASA Technical Reports Server (NTRS)
1985-01-01
The objectives are to define the most efficient and cost effective methods for scavenging cryogenic and storable propellants and then define the requirements for these scavenging systems. For cryogenic propellants, scavenging is the transfer of propellants from the Shuttle orbiter external tank (ET) and/or main propulsion subsystems (MPS) propellant lines into storage tanks located in the orbiter payload bay for delivery to the user station by a space based transfer stage or the Space Transportation System (STS) by direct insertion. For storable propellants, scavenging is the direct transfer from the orbital maneuvering subsystem (OMS) and/or tankage in the payload bay to users in LEO as well as users in the vicinity of the Space Station.
NASA Astrophysics Data System (ADS)
1983-04-01
The overall configuration and modules of the initial and evolved space station are described as well as tended industrial and polar platforms. The mass properties that are the basis for costing are summarized. User friendly attributes (interfaces, resources, and facilities) are identified for commercial; science and applications; industrial park; international participation; national security; and the external tank option. Configuration alternates studied to determine a baseline are examined. Commonality for clustered 3-man and 9-man stations are considered as well as the use of tethered platforms. Requirements are indicated for electrical, communication and tracking; data management Subsystem requirements for electrical, data management, communication and tracking, environment control/life support system; and guidance navigation and control subsystems are identified.
NASA Astrophysics Data System (ADS)
Cretcher, C. K.
1980-11-01
The various types of solar domestic hot water systems are discussed including their advantages and disadvantages. The problems that occur in hydronic solar heating systems are reviewed with emphasis on domestic hot water applicatons. System problems in retrofitting of residential buildings are also discussed including structural and space constraints for various components and subsystems. System design parameters include various collector sizing methods, collector orientation, storage capacity and heat loss from pipes and tanks. The installation costs are broken down by components and subsystems. The approach used for utility economic impact analysis is reviewed. The simulation is described, and the results of the economic impact analysis are given. A summary assessment is included.
NASA Astrophysics Data System (ADS)
Barkstrom, B. R.; Loeb, N. G.; Wielicki, B. A.
2017-12-01
Verification, Validation, and Uncertainty Quantification (VVUQ) are key actions that support conclusions based on Earth science data. Communities of data producers and users must undertake VVUQ when they create and use their data. The strategies [S] and tools [T] suggested below come from successful use on two large NASA projects. The first was the Earth Radiation Budget Experiment (ERBE). The second is the investigation of Clouds and the Earth's Radiant Energy System (CERES). [S] 1. Partition the production system into subsystems that deal with data transformations confined to limited space and time scales. Simplify the subsystems to minimize the number of data transformations in each subsystem. [S] 2. Derive algorithms from the fundamental physics and chemistry governing the parameters in each subsystem including those for instrument calibration. [S] 3. Use preliminary uncertainty estimates to detect unexpected discrepancies. Removing these requires diagnostic work as well as development and testing of fixes. [S] 4. Make sure there are adequate resources to support multiple end-to-end reprocessing of all data products. [T] 1. Create file identifiers that accommodate temporal and spatial sequences of data files and subsystem version changes. [T] 2. Create libraries of parameters used in common by different subsystems to reduce errors due to inconsistent values. [T] 3. Maintain a list of action items to record progress on resolving discrepancies. [T] 4. Plan on VVUQ activities that use independent data sources and peer review before distributing and archiving data. The goal of VVUQ is to provide a transparent link between the data and the physics and chemistry governing the measured quantities. The VVUQ effort also involves specialized domain experience and nomenclature. It often requires as much effort as the original system development. ERBE and CERES demonstrated that these strategies and tools can reduce the cost of VVUQ for Earth science data products.
NASA Astrophysics Data System (ADS)
Liu, D.; Tian, F.; Lin, M.; Sivapalan, M.
2014-04-01
The complex interactions and feedbacks between humans and water are very essential issues but are poorly understood in the newly proposed discipline of socio-hydrology (Sivapalan et al., 2012). An exploratory model with the appropriate level of simplification can be valuable to improve our understanding of the co-evolution and self-organization of socio-hydrological systems driven by interactions and feedbacks operating at different scales. In this study, a simple coupled modeling framework for socio-hydrology co-evolution is developed for the Tarim River Basin in Western China, and is used to illustrate the explanatory power of such a model. The study area is the mainstream of the Tarim River, which is divided into two modeling units. The socio-hydrological system is composed of four parts, i.e. social sub-system, economic sub-system, ecological sub-system, and hydrological sub-system. In each modeling unit, four coupled ordinary differential equations are used to simulate the dynamics of the social sub-system represented by human population, the economic sub-system represented by irrigated crop area, the ecological sub-system represented by natural vegetation cover and the hydrological sub-system represented by stream discharge. The coupling and feedback processes of the four dominant sub-systems (and correspondingly four state variables) are integrated into several internal system characteristics interactively and jointly determined by themselves and by other coupled systems. For example, the stream discharge is coupled to the irrigated crop area by the colonization rate and mortality rate of the irrigated crop area in the upper reach and the irrigated area is coupled to stream discharge through irrigation water consumption. In a similar way, the stream discharge and natural vegetation cover are coupled together. The irrigated crop area is coupled to human population by the colonization rate and mortality rate of the population. The inflow of the lower reach is determined by the outflow from the upper reach. The natural vegetation cover in the lower reach is coupled to the outflow from the upper reach and governed by regional water resources management policy. The co-evolution of the Tarim socio-hydrological system is then analyzed within this modeling framework to gain insights into the overall system dynamics and its sensitivity to the external drivers and internal system variables. In the modeling framework, the state of each subsystem is holistically described by one state variable and the framework is flexible enough to comprise more processes and constitutive relationships if they are needed to illustrate the interaction and feedback mechanisms of the human-water system.
Space Station needs, attributes and architectural options, volume 2, book 3: Cost and programmatics
NASA Technical Reports Server (NTRS)
1983-01-01
The cost and programmatic considerations which integrate mission requirements and architectural options into a cohesive system for exploitation of space opportunities within affordable limits are discussed. The mission requirements, baseline architecture, a top level baseline schedule, and acquisition costs are summarized. The work breakdown structure (WBS) used to structure the program, and the WBS dictionary are included. The costing approach used, including the operation of the primary costing tool, the SPACE cost model are described. The rationale for the choice of cost estimating relationships is given and costs at the module level are shown. Detailed costs at the subsystem level are shown. The baseline schedule and annual funding profiles are provided. Alternate schedules are developed to provide different funding profiles. Alternate funding sources are discussed and foreign and contractor participation is outlined. The results of the benefit analysis are given and the accrued benefits deriving from an implemented space station program are outlined.
NASA Astrophysics Data System (ADS)
Housh, M.; Ng, T.; Cai, X.
2012-12-01
The environmental impact is one of the major concerns of biofuel development. While many other studies have examined the impact of biofuel expansion on stream flow and water quality, this study examines the problem from the other side - will and how a biofuel production target be affected by given environmental constraints. For this purpose, an integrated model comprises of different sub-systems of biofuel refineries, transportation, agriculture, water resources and crops/ethanol market has been developed. The sub-systems are integrated into one large-scale model to guide the optimal development plan considering the interdependency between the subsystems. The optimal development plan includes biofuel refineries location and capacity, refinery operation, land allocation between biofuel and food crops, and the corresponding stream flow and nitrate load in the watershed. The watershed is modeled as a network flow, in which the nodes represent sub-watersheds and the arcs are defined as the linkage between the sub-watersheds. The runoff contribution of each sub-watershed is determined based on the land cover and the water uses in that sub-watershed. Thus, decisions of other sub-systems such as the land allocation in the land use sub-system and the water use in the refinery sub-system define the sources and the sinks of the network. Environmental policies will be addressed in the integrated model by imposing stream flow and nitrate load constraints. These constraints can be specified by location and time in the watershed to reflect the spatial and temporal variation of the regulations. Preliminary results show that imposing monthly water flow constraints and yearly nitrate load constraints will change the biofuel development plan dramatically. Sensitivity analysis is performed to examine how the environmental constraints and their spatial and the temporal distribution influence the overall biofuel development plan and the performance of each of the sub-systems. Additional scenarios are analyzed to show the synergies of crop pattern choice (first versus second generation of biofuel crops), refinery technology adaptation (particularly on water use), refinery plant distribution, and economic incentives in terms of balanced environmental protection and bioenergy development objectives.
Investigation of L-band shipboard antennas for maritime satellite applications
NASA Technical Reports Server (NTRS)
Heckert, G. P.
1972-01-01
A basic conceptual investigation of low cost L-band antenna subsystems for shipboard use was conducted by identifying the various pertinent design trade-offs and related performance characteristics peculiar to the civilian maritime application, and by comparing alternate approaches for their simplicity and general suitability. The study was not directed at a single specific proposal, but was intended to be parametric in nature. Antenna system concepts were to be investigated for a range of gain of 3 to 18 dB, with a value of about 10 dB considered as a baseline reference. As the primary source of potential complexity in shipboard antennas, which have beamwidths less than hemispherical as the beam pointing or selecting mechanism, major emphasis was directed at this aspect. Three categories of antenna system concepts were identified: (1) mechanically pointed, single-beam antennas; (2) fixed antennas with switched-beams; and (3) electronically-steered phased arrays. It is recommended that an L-band short backfire antenna subsystem, including a two-axis motor driven gimbal mount, and necessary single channel monopulse tracking receiver portions be developed for demonstration of performance and subsystem simplicity.
Tool for Sizing Analysis of the Advanced Life Support System
NASA Technical Reports Server (NTRS)
Yeh, Hue-Hsie Jannivine; Brown, Cheryl B.; Jeng, Frank J.
2005-01-01
Advanced Life Support Sizing Analysis Tool (ALSSAT) is a computer model for sizing and analyzing designs of environmental-control and life support systems (ECLSS) for spacecraft and surface habitats involved in the exploration of Mars and Moon. It performs conceptual designs of advanced life support (ALS) subsystems that utilize physicochemical and biological processes to recycle air and water, and process wastes in order to reduce the need of resource resupply. By assuming steady-state operations, ALSSAT is a means of investigating combinations of such subsystems technologies and thereby assisting in determining the most cost-effective technology combination available. In fact, ALSSAT can perform sizing analysis of the ALS subsystems that are operated dynamically or steady in nature. Using the Microsoft Excel spreadsheet software with Visual Basic programming language, ALSSAT has been developed to perform multiple-case trade studies based on the calculated ECLSS mass, volume, power, and Equivalent System Mass, as well as parametric studies by varying the input parameters. ALSSAT s modular format is specifically designed for the ease of future maintenance and upgrades.
The Economic Potential of Two Nuclear-Renewable Hybrid Energy Systems
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ruth, Mark; Cutler, Dylan; Flores-Espino, Francisco
Tightly coupled nuclear-renewable hybrid energy systems (N-R HESs) are an option that can generate zero-carbon, dispatchable electricity and provide zero-carbon energy for industrial processes at a lower cost than alternatives. N-R HESs are defined as systems that are managed by a single entity and link a nuclear reactor that generates heat, a thermal power cycle for heat to electricity conversion, at least one renewable energy source, and an industrial process that uses thermal and/or electrical energy. This report provides results of an analysis of two N-R HES scenarios. The first is a Texas-synthetic gasoline scenario that includes four subsystems: amore » nuclear reactor, thermal power cycle, wind power plant, and synthetic gasoline production technology. The second is an Arizona-desalination scenario with its four subsystems a nuclear reactor, thermal power cycle, solar photovoltaics, and a desalination plant. The analysis focuses on the economics of the N-R HESs and how they compare to other options, including configurations without all the subsystems in each N-R HES and alternatives where the energy is provided by natural gas.« less
System driven technology selection for future European launch systems
NASA Astrophysics Data System (ADS)
Baiocco, P.; Ramusat, G.; Sirbi, A.; Bouilly, Th.; Lavelle, F.; Cardone, T.; Fischer, H.; Appel, S.
2015-02-01
In the framework of the next generation launcher activity at ESA, a top-down approach and a bottom-up approach have been performed for the identification of promising technologies and alternative conception of future European launch vehicles. The top-down approach consists in looking for system-driven design solutions and the bottom-up approach features design solutions leading to substantial advantages for the system. The main investigations have been focused on the future launch vehicle technologies. Preliminary specifications have been used in order to permit sub-system design to find the major benefit for the overall launch system. The development cost, non-recurring and recurring cost, industrialization and operational aspects have been considered as competitiveness factors for the identification and down-selection of the most interesting technologies. The recurring cost per unit payload mass has been evaluated. The TRL/IRL has been assessed and a preliminary development plan has been traced for the most promising technologies. The potentially applicable launch systems are Ariane and VEGA evolution. The main FLPP technologies aim at reducing overall structural mass, increasing structural margins for robustness, metallic and composite containment of cryogenic hydrogen and oxygen propellants, propellant management subsystems, elements significantly reducing fabrication and operational costs, avionics, pyrotechnics, etc. to derive performing upper and booster stages. Application of the system driven approach allows creating performing technology demonstrators in terms of need, demonstration objective, size and cost. This paper outlines the process of technology down selection using a system driven approach, the accomplishments already achieved in the various technology fields up to now, as well as the potential associated benefit in terms of competitiveness factors.
Amelkin, Alexander A; Blagoveschenskaya, Margarita M; Lobanov, Yury V; Amelkin, Anatoly K
2003-01-01
The purpose of the present work is to work out an approach for the development of software and the choice of hardware structures when designing subsystems for automatic control of technological processes realized in living objects containing limited space (microenvironment). The subsystems for automatic control of the microenvironment (SACME) under development use the Devices for Air Prophylactic Treatment, Aeroionization, and Purification (DAPTAP) as execution units for increasing the level of safety and quality of agricultural raw material and foodstuffs, for reducing the losses of agricultural produce during storage and cultivation, as well as for intensifying the processes of activation of agricultural produce and industrial microorganisms. A set of interconnected SACMEs works within the framework of a general microenvironmental system (MES). In this research, the population of baker's yeast is chosen as a basic object of control under the industrial fed-batch cultivation in a bubbling bioreactor. This project is an example of a minimum cost automation approach. The microenvironment optimal control problem for baker's yeast cultivation is reduced from a profit maximum to the maximization of overall yield by the reason that the material flow-oriented specific cost correlates closely with the reciprocal value of the overall yield. Implementation of the project partially solves a local sustainability problem and supports a balance of microeconomical, microecological and microsocial systems within a technological subsystem realized in a microenvironment maintaining an optimal value of economical criterion (e.g. minimum material, flow-oriented specific cost) and ensuring: (a) economical growth (profit increase, raw material saving); (b) high security, safety and quality of agricultural raw material during storage process and of food produce during a technological process; elimination of the contact of gaseous harmful substances with a subproduct during various technological stages; (c) improvement of labour conditions for industrial personnel from an ecological point of view (positive effect of air aeroionization and purification on human organism promoting strengthened health and an increase in life duration, pulverent and gaseous chemical and biological impurity removal). An alternative aspect of a controlled living microenvironment forming is considered.
NASA Technical Reports Server (NTRS)
Chullen, Cinda; Conger, Bruce; Korona, Adam; Kanne, Bryan; McMillin, Summer; Paul, Thomas; Norcross, Jason; Alonso, Jesus Delgado; Swickrath, Mike
2015-01-01
NASA is pursuing technology development of an Advanced Extravehicular Mobility Unit (AEMU) which is an integrated assembly made up of primarily a pressure garment system and a portable life support subsystem (PLSS). The PLSS is further composed of an oxygen subsystem, a ventilation subsystem, and a thermal subsystem. One of the key functions of the ventilation system is to remove and control the carbon dioxide (CO2) delivered to the crewmember. Carbon dioxide washout is the mechanism by which CO2 levels are controlled within the space suit helmet to limit the concentration of CO2 inhaled by the crew member. CO2 washout performance is a critical parameter needed to ensure proper and robust designs that are insensitive to human variabilities in a space suit. A suited manikin test apparatus (SMTA) was developed to augment testing of the PLSS ventilation loop in order to provide a lower cost and more controlled alternative to human testing. The CO2 removal function is performed by the regenerative Rapid Cycle Amine (RCA) within the PLSS ventilation loop and its performance is evaluated within the integrated SMTA and Ventilation Loop test system. This paper will provide a detailed description of the schematics, test configurations, and hardware components of this integrated system. Results and analysis of testing performed with this integrated system will be presented within this paper.
Autonomous navigation and mobility for a planetary rover
NASA Technical Reports Server (NTRS)
Miller, David P.; Mishkin, Andrew H.; Lambert, Kenneth E.; Bickler, Donald; Bernard, Douglas E.
1989-01-01
This paper presents an overview of the onboard subsystems that will be used in guiding a planetary rover. Particular emphasis is placed on the planning and sensing systems and their associated costs, particularly in computation. Issues that will be used in evaluating trades between the navigation system and mobility system are also presented.
General Training System; GENTRAS. Final Report.
ERIC Educational Resources Information Center
International Business Machines Corp., Gaithersburg, MD. Federal Systems Div.
GENTRAS (General Training System) is a computer-based training model for the Marine Corps which makes use of a systems approach. The model defines the skill levels applicable for career growth and classifies and defines the training needed for this growth. It also provides a training cost subsystem which will provide a more efficient means of…
Millimeter wave satellite concepts. Volume 2: Technical report
NASA Technical Reports Server (NTRS)
Hilsen, N. B.; Holland, L. D.; Wallace, R. W.; Kelly, D. L.; Thomas, R. R.; Vogler, F. H.
1979-01-01
Identification of technologies for millimeter satellite communication systems, and assessment of the relative risks of these technologies, were accomplished through subsystem modeling and link optimization for both point-to-point and broadcast applications. The results, in terms of annual cost per channel to the user from a commercial view point, are described.
Automotive Stirling Engine Development Program
NASA Technical Reports Server (NTRS)
Nightingale, N.; Ernst, W.; Richey, A.; Simetkosky, M.; Antonelli, M. (Editor)
1982-01-01
Activities performed on Mod I engine testing and test results; the manufacture, assembly, and test of a Mod I engine in the United States; design initiation of the Mod I-A engine system; transient performance testing; Stirling reference engine manufacturing and reduced size studies; components and subsystems; and the study and test of low cost alloys are summarized.
NASA Technical Reports Server (NTRS)
Stuchlik, David William
2017-01-01
WASP is a NASA developed Fine Pointing System adaptable to a variety of Science Instruments. Standardized System with Reusable Parts to Minimize the Cost to Users and NASA. Supports Multiple Science Disciplines and a wide range of Masses and Inertias. Currently Operational and Available for Science Collaborations.
NASA Technical Reports Server (NTRS)
McCurry, J.
1995-01-01
The purpose of the TA-2 contract was to provide advanced launch vehicle concept definition and analysis to assist NASA in the identification of future launch vehicle requirements. Contracted analysis activities included vehicle sizing and performance analysis, subsystem concept definition, propulsion subsystem definition (foreign and domestic), ground operations and facilities analysis, and life cycle cost estimation. This document is part of the final report for the TA-2 contract. The final report consists of three volumes: Volume 1 is the Executive Summary, Volume 2 is Technical Results, and Volume 3 is Program Cost Estimates. The document-at-hand, Volume 1, provides a summary description of the technical activities that were performed over the entire contract duration, covering three distinct launch vehicle definition activities: heavy-lift (300,000 pounds injected mass to low Earth orbit) launch vehicles for the First Lunar Outpost (FLO), medium-lift (50,000-80,000 pounds injected mass to low Earth orbit) launch vehicles, and single-stage-to-orbit (SSTO) launch vehicles (25,000 pounds injected mass to a Space Station orbit).
Molten salt thermal energy storage subsystem for solar thermal central receiver plants
NASA Astrophysics Data System (ADS)
Wells, P. B.; Nassopoulos, G. P.
1982-02-01
The development of a low cost thermal energy storage subsystem for large solar plants is described. Molten nitrate salt is used as both the solar plant working fluid and the storage medium. The storage system consists of a specially designed hot tank to hold salt at a storage temperature of 839K (1050 deg F) and a separate carbon steel cold tank to hold the salt after its thermal energy has been extracted to generate steam. The hot tank is lined with insulating firebrick to reduce the shell temperature to 561K (550 deg F) so that a low cost carbon steel shell is used. The internal insulation is protected from the hot salt by a unique metal liner with orthogonal corrugations to allow for numerous cycles of thermal expansion and contraction. A preliminary design for a large commercial size plant (1200 MWh sub +), a laboratory test program for the critical components, and the design, construction, and test of a small scale (7 MWH sub t) research experiment at the Central Receiver Test Facility in Albuquerque, New Mexico is described.
Conceptual design of the 6 MW Mod-5A wind turbine generator
NASA Technical Reports Server (NTRS)
Barton, R. S.; Lucas, W. C.
1982-01-01
The General Electric Company, Advanced Energy Programs Department, is designing under DOE/NASA sponsorship the MOD-5A wind turbine system which must generate electricity for 3.75 cent/KWH (1980) or less. During the Conceptual Design Phase, completed in March, 1981, the MOD-5A WTG system size and features were established as a result of tradeoff and optimization studies driven by minimizing the system cost of energy (COE). This led to a 400' rotor diameter size. The MOD-5A system which resulted is defined in this paper along with the operational and environmental factors that drive various portions of the design. Development of weight and cost estimating relationships (WCER's) and their use in optimizing the MOD-5A are discussed. The results of major tradeoff studies are also presented. Subsystem COE contributions for the 100th unit are shown along with the method of computation. Detailed descriptions of the major subsystems are given, in order that the results of the various trade and optimization studies can be more readily visualized.
Sensitivity analysis of the space shuttle to ascent wind profiles
NASA Technical Reports Server (NTRS)
Smith, O. E.; Austin, L. D., Jr.
1982-01-01
A parametric sensitivity analysis of the space shuttle ascent flight to the wind profile is presented. Engineering systems parameters are obtained by flight simulations using wind profile models and samples of detailed (Jimsphere) wind profile measurements. The wind models used are the synthetic vector wind model, with and without the design gust, and a model of the vector wind change with respect to time. From these comparison analyses an insight is gained on the contribution of winds to ascent subsystems flight parameters.
The Gemini Planet Imager: integration and status
NASA Astrophysics Data System (ADS)
Macintosh, Bruce A.; Anthony, Andre; Atwood, Jennifer; Barriga, Nicolas; Bauman, Brian; Caputa, Kris; Chilcote, Jeffery; Dillon, Daren; Doyon, René; Dunn, Jennifer; Gavel, Donald T.; Galvez, Ramon; Goodsell, Stephen J.; Graham, James R.; Hartung, Markus; Isaacs, Joshua; Kerley, Dan; Konopacky, Quinn; Labrie, Kathleen; Larkin, James E.; Maire, Jerome; Marois, Christian; Millar-Blanchaer, Max; Nunez, Arturo; Oppenheimer, Ben R.; Palmer, David W.; Pazder, John; Perrin, Marshall; Poyneer, Lisa A.; Quirez, Carlos; Rantakyro, Frederik; Reshtov, Vlad; Saddlemyer, Leslie; Sadakuni, Naru; Savransky, Dmitry; Sivaramakrishnan, Anand; Smith, Malcolm; Soummer, Remi; Thomas, Sandrine; Wallace, J. Kent; Weiss, Jason; Wiktorowicz, Sloane
2012-09-01
The Gemini Planet Imager is a next-generation instrument for the direct detection and characterization of young warm exoplanets, designed to be an order of magnitude more sensitive than existing facilities. It combines a 1700-actuator adaptive optics system, an apodized-pupil Lyot coronagraph, a precision interferometric infrared wavefront sensor, and a integral field spectrograph. All hardware and software subsystems are now complete and undergoing integration and test at UC Santa Cruz. We will present test results on each subsystem and the results of end-to-end testing. In laboratory testing, GPI has achieved a raw contrast (without post-processing) of 10-6 5σ at 0.4", and with multiwavelength speckle suppression, 2x10-7 at the same separation.
The Detector Subsystem for the SXS Instrument on the Astro-H Observatory
NASA Technical Reports Server (NTRS)
Porter, Frederick; Adams, J. S.; Brown, G. V.; Chervenak, J. A.; Chiao, M. P.; Fujimoto, R.; Ishisaki, Y.; Kelley, R. L.; Kilbourne, C. A.; McCammon, D.;
2011-01-01
The Soft X-ray Spectrometer (SXS) instrument on the Astro-H observatory is based on a 36 pixel x-ray calorimeter array cooled to 50 mK in a sophisticated spaceflight cryostat. The SXS is a true spatial-spectral instrument, where each spatially discrete pixel functions as a high-resolution spectrometer. Here we discuss the SXS detector subsystem that includes the detector array, the anticoincidence detector, the first stage amplifiers, the thermal and mechanical staging of the detector, and the cryogenic bias electronics. The design of the SXS detector subsystem has significant heritage from the Suzaku/XRS instrument but has some important modifications that increase performance margins and simplify the focal plane assembly. Notable improvements include x-ray absorbers with significantly lower heat capacity, improved load resistors, improved thermometry, and a decreased sensitivity to thermal radiation. These modifications have yielded an energy resolution of 3.5-4.0 eV FWHM at 6 keV for representative devices in the laboratory, giving considerable margin against the 7 eV instrument requirement. We expect similar performance in flight
NASA Astrophysics Data System (ADS)
Plesniak, A.; Garboushian, V.
2012-10-01
In 2011, the Amonix Advanced Technology Group was awarded DOE SunShot funding in the amount of 4.5M to design a new Balance of System (BOS) architecture utilizing Amonix MegaModules™ focused on reaching the SunShot goal of 0.06-$0.08/kWhr LCOE. The project proposal presented a comprehensive re-evaluation of the cost components of a utility scale CPV plant and identified critical areas of focus where innovation is needed to achieve cost reduction. As the world's premier manufacturer and most experienced installer of CPV power plants, Amonix is uniquely qualified to lead a rethinking of BOS architecture for CPV. The presentation will focus on the structure of the BOS-X approach, which looks for the next wave of cost reduction in CPV through evaluation of non-module subsystems and the interaction between subsystems during the lifecycle of a solar power plant. Innovation around nonmodule components is minimal to date because CPV companies are just now getting enough practice through completion of large projects to create ideas and tests on how to improve baseline designs and processes. As CPV companies increase their installed capacity, they can utilize an approach similar to the methodology of BOS-X to increase the competitiveness of their product. Through partnership with DOE, this holistic approach is expected to define a path for CPV well aligned with the goals of the SunShot Initiative.
System Estimates Radius of Curvature of a Segmented Mirror
NASA Technical Reports Server (NTRS)
Rakoczy, John
2008-01-01
A system that estimates the global radius of curvature (GRoC) of a segmented telescope mirror has been developed for use as one of the subsystems of a larger system that exerts precise control over the displacements of the mirror segments. This GRoC-estimating system, when integrated into the overall control system along with a mirror-segment- actuation subsystem and edge sensors (sensors that measure displacements at selected points on the edges of the segments), makes it possible to control the GROC mirror-deformation mode, to which mode contemporary edge sensors are insufficiently sensitive. This system thus makes it possible to control the GRoC of the mirror with sufficient precision to obtain the best possible image quality and/or to impose a required wavefront correction on incoming or outgoing light. In its mathematical aspect, the system utilizes all the information available from the edge-sensor subsystem in a unique manner that yields estimates of all the states of the segmented mirror. The system does this by exploiting a special set of mirror boundary conditions and mirror influence functions in such a way as to sense displacements in degrees of freedom that would otherwise be unobservable by means of an edge-sensor subsystem, all without need to augment the edge-sensor system with additional metrological hardware. Moreover, the accuracy of the estimates increases with the number of mirror segments.
Excitation-scanning hyperspectral imaging system for microscopic and endoscopic applications
NASA Astrophysics Data System (ADS)
Mayes, Sam A.; Leavesley, Silas J.; Rich, Thomas C.
2016-04-01
Current microscopic and endoscopic technologies for cancer screening utilize white-light illumination sources. Hyper-spectral imaging has been shown to improve sensitivity while retaining specificity when compared to white-light imaging in both microscopy and in vivo imaging. However, hyperspectral imaging methods have historically suffered from slow acquisition times due to the narrow bandwidth of spectral filters. Often minutes are required to gather a full image stack. We have developed a novel approach called excitation-scanning hyperspectral imaging that provides 2-3 orders of magnitude increased signal strength. This reduces acquisition times significantly, allowing for live video acquisition. Here, we describe a preliminary prototype excitation-scanning hyperspectral imaging system that can be coupled with endoscopes or microscopes for hyperspectral imaging of tissues and cells. Our system is comprised of three subsystems: illumination, transmission, and imaging. The illumination subsystem employs light-emitting diode arrays to illuminate at different wavelengths. The transmission subsystem utilizes a unique geometry of optics and a liquid light guide. Software controls allow us to interface with and control the subsystems and components. Digital and analog signals are used to coordinate wavelength intensity, cycling and camera triggering. Testing of the system shows it can cycle 16 wavelengths at as fast as 1 ms per cycle. Additionally, more than 18% of the light transmits through the system. Our setup should allow for hyperspectral imaging of tissue and cells in real time.
Space station environmental control and life support systems test bed program - an overview
NASA Astrophysics Data System (ADS)
Behrend, Albert F.
As the National Aeronautics and Space Administration (NASA) begins to intensify activities for development of the Space Station, decisions must be made concerning the technical state of the art that will be baselined for the initial Space Station system. These decisions are important because significant potential exists for enhancing system performance and for reducing life-cycle costs. However, intelligent decisions cannot be made without an adequate assessment of new and ready technologies, i.e., technologies which are sufficiently mature to allow predevelopment demonstrations to prove their application feasibility and to quantify the risk associated with their development. Therefore, the NASA has implemented a technology development program which includes the establishment of generic test bed capabilities in which these new technologies and approaches can be tested at the prototype level. One major Space Station subsystem discipline in which this program has been implemented is the environmental control and life support system (ECLSS). Previous manned space programs such as Gemini, Apollo, and Space Shuttle have relied heavily on consumables to provide environmental control and life support services. However, with the advent of a long-duration Space Station, consumables must be reduced within technological limits to minimize Space Station resupply penalties and operational costs. The use of advanced environmental control and life support approaches involving regenerative processes offers the best solution for significant consumables reduction while also providing system evolutionary growth capability. Consequently, the demonstration of these "new technologies" as viable options for inclusion in the baseline that will be available to support a Space Station initial operational capability in the early 1990's becomes of paramount importance. The mechanism by which the maturity of these new regenerative life support technologies will be demonstrated is the Space Station ECLSS Test Bed Program. The Space Station ECLSS Test Bed Program, which is managed by the NASA, is designed to parallel and to provide continuing support to the Space Station Program. The prime objective of this multiphase test bed program is to provide viable, mature, and enhancing technical options in time for Space Station implementation. To accomplish this objective, NASA is actively continuing the development and testing of critical components and engineering preprototype subsystems for urine processing, washwater recovery, water quality monitoring, carbon dioxide removal and reduction, and oxygen generation. As part of the ECLSS Test Bed Program, these regenerative subsystems and critical components are tested in a development laboratory to characterize subsystem performance and to identify areas in which further technical development is required. Proven concepts are then selected for development into prototype subsystems in which flight issues such as packaging and maintenance are addressed. These subsystems then are to be assembled as an integrated system and installed in an integrated systems test bed facility for extensive unmanned and manned testing.
Radiation and shielding study for the International Ultraviolet Explorer
NASA Technical Reports Server (NTRS)
Baze, M.; Firminhac, R. H.; Horne, W. E.; Kennedy, R. C.; Measel, P. R.; Sivo, L. L.; Wilkinson, M. C.
1974-01-01
Technical advisory services to ensure integrity of parts and material exposed to energetic particle radiation for the IUE scientific instruments, spacecraft, and subsystems are provided. A significant potential for interference, degradation, or failure for unprotected or sensitive items was found. Vulnerable items were identified, and appropriate tests, changes, and shields were defined.
NASA Astrophysics Data System (ADS)
Hameetman, G. J.; Dekker, G. J.
1993-11-01
The Italian satellite (with a large Dutch contribution) SAX is a scientific satellite which has the mission to study roentgen sources. One main requirement for the Attitude and Orbit Control Subsystem (AOCS) is to achieve and maintain a stable pointing accuracy with a limit cycle of less than 90 arcsec during pointings of maximal 28 hours. The main SAX instrument, the Narrow Field Instrument, is highly sensitive to (indirect) radiation coming from the Sun. This sensitivity leads to another main requirement that under no circumstances the safe attitude domain may be left. The paper describes the application software in relation with the overall SAX AOCS subsystem, the CASE tools that have been used during the development, some advantages and disadvantages of the use of these tools, the measures taken to meet the more or less conflicting requirements of reliability and flexibility, and the lessons learned during development. The quality of the approach to the development has proven the (separately executed) hardware/software integration tests. During these tests, a neglectible number of software errors has been detected in the application software.
Payload accommodation and development planning tools - A Desktop Resource Leveling Model (DRLM)
NASA Technical Reports Server (NTRS)
Hilchey, John D.; Ledbetter, Bobby; Williams, Richard C.
1989-01-01
The Desktop Resource Leveling Model (DRLM) has been developed as a tool to rapidly structure and manipulate accommodation, schedule, and funding profiles for any kind of experiments, payloads, facilities, and flight systems or other project hardware. The model creates detailed databases describing 'end item' parameters, such as mass, volume, power requirements or costs and schedules for payload, subsystem, or flight system elements. It automatically spreads costs by calendar quarters and sums costs or accommodation parameters by total project, payload, facility, payload launch, or program phase. Final results can be saved or printed out, automatically documenting all assumptions, inputs, and defaults.
X-Band Radar for Studies of Tropical Storms from High Altitude UAV Platform
NASA Technical Reports Server (NTRS)
Rodriquez, Shannon; Heymsfield, Gerald; Li, Lihua; Bradley, Damon
2007-01-01
The increased role of unmanned aerial vehicles (UAV) in NASA's suborbital program has created a strong interest in the development of instruments with new capabilities, more compact sizes and reduced weights than the instruments currently operated on manned aircrafts. There is a strong demand and tremendous potential for using high altitude UAV (HUAV) to carry weather radars for measurements of reflectivity and wind fields from tropical storms. Tropical storm genesis frequently occurs in ocean regions that are inaccessible to piloted aircraft due to the long off shore range and the required periods of time to gather significant data. Important factors of interest for the study of hurricane genesis include surface winds, profiled winds, sea surface temperatures, precipitation, and boundary layer conditions. Current satellite precipitation and surface wind sensors have resolutions that are too large and revisit times that are too infrequent to study this problem. Furthermore, none of the spaceborne sensors measure winds within the storm itself. A dual beam X-band Doppler radar, UAV Radar (URAD), is under development at the NASA Goddard Space Flight Center for the study of tropical storms from HUAV platforms, such as a Global Hawk. X-band is the most desirable frequency for airborne weather radars since these can be built in a relatively compact size using off-the-shelf components which cost significantly less than other higher frequency radars. Furthermore, X-band radars provide good sensitivity with tolerable attenuation in storms. The low-cost and light-weight URAD will provide new capabilities for studying hurricane genesis by analyzing the vertical structure of tropical cyclones as well as 3D reflectivity and wind fields in clouds. It will enable us to measure both the 3D precipitation structure and surface winds by using two antenna beams: fixed nadir and conical scanning each produced by its associated subsystem. The nadir subsystem is a magnetron based radar modified from a marine radar transceiver. It is capable of measuring vertical reflectivity and velocity profile while being a lower-cost, smaller size, and lighter weight version of the NASA ER-2 Doppler Radar (EDOP), which has flown during many NASA field campaigns and has provided valuable scientific information on hurricanes and weather phenomena. Unfortunately, EDOP is too large and heavy for most UAV platforms, but the experience gained with this instrument provided us with the heritage to build a new low-cost, light-weight, smaller system that will be capable of flying on UAVs. The scanning subsystem uses a TWT transmitter and provides measurements of 3D reflectivity/wind fields in-clouds. Conical scanning of the radar beam at a 35 deg. incidence angle will also provide information of surface wind speed and direction derived from the surface return over a single 360 deg. sweep. URAD data system will be Linux based with the capability of autonomous operation. It will utilize cutting edge digital receiver and FPGA technologies to carry out the data acquisition and processing tasks. High speed navigation data from the aircraft will also be captured and saved along with radar data for 3D measurement field reconstruction and aircraft motion correction. There is a tremendous potential for UAVs to carry down-looking weather radars for measurements of reflectivity, horizontal and vertical winds from tropical storms. With operation from HUAV platforms, the dual beam X-band radar under development promises to provide greatly needed information for tropical storm research.
Glancing and Then Looking: On the Role of Body, Affect, and Meaning in Cognitive Control
Su, Li; Bowman, Howard; Barnard, Philip
2011-01-01
In humans, there is a trade-off between the need to respond optimally to the salient environmental stimuli and the need to meet our long-term goals. This implies that a system of salience sensitive control exists, which trades task-directed processing off against monitoring and responding to potentially high salience stimuli that are irrelevant to the current task. Much cognitive control research has attempted to understand these mechanisms using non-affective stimuli. However, recent research has emphasized the importance of emotions, which are a major factor in the prioritization of competing stimuli and in directing attention. While relatively mature theories of cognitive control exist for non-affective settings, exactly how emotions modulate cognitive processes is less well understood. The attentional blink (AB) task is a useful experimental paradigm to reveal the dynamics of both cognitive and affective control in humans. Hence, we have developed the glance–look model, which has replicated a broad profile of data on the semantic AB task and characterized how attentional deployment is modulated by emotion. Taking inspiration from Barnard’s Interacting Cognitive Subsystems, the model relies on a distinction between two levels of meaning: implicational and propositional, which are supported by two corresponding mental subsystems: the glance and the look respectively. In our model, these two subsystems reflect the central engine of cognitive control and executive function. In particular, the interaction within the central engine dynamically establishes a task filter for salient stimuli using a neurobiologically inspired learning mechanism. In addition, the somatic contribution of emotional effects is modeled by a body-state subsystem. We argue that stimulus-driven interaction among these three subsystems governs the movement of control between them. The model also predicts attenuation effects and fringe awareness during the AB. PMID:22194729
Methods for the development of a bioregenerative life support system
NASA Technical Reports Server (NTRS)
Goldman, Michelle; Gomez, Shawn; Voorhees, Mike
1990-01-01
Presented here is a rudimentary approach to designing a life support system based on the utilization of plants and animals. The biggest stumbling block in the initial phases of developing a bioregenerative life support system is encountered in collecting and consolidating the data. If a database existed for the systems engineer so that he or she may have accurate data and a better understanding of biological systems in engineering terms, then the design process would be simplified. Also addressed is a means of evaluating the subsystems chosen. These subsystems are unified into a common metric, kilograms of mass, and normalized in relation to the throughput of a few basic elements. The initial integration of these subsystems is based on input/output masses and eventually balanced to a point of operation within the inherent performance ranges of the organisms chosen. At this point, it becomes necessary to go beyond the simplifying assumptions of simple mass relationships and further define for each organism the processes used to manipulate the throughput matter. Mainly considered here is the fact that these organisms perform input/output functions on differing timescales, thus establishing the need for buffer volumes or appropriate subsystem phasing. At each point in a systematic design it is necessary to disturb the system and discern its sensitivity to the disturbance. This can be done either through the introduction of a catastrophic failure or by applying a small perturbation to the system. One example is increasing the crew size. Here the wide range of performance characteristics once again shows that biological systems have an inherent advantage in responding to systemic perturbations. Since the design of any space-based system depends on mass, power, and volume requirements, each subsystem must be evaluated in these terms.
Glancing and then looking: on the role of body, affect, and meaning in cognitive control.
Su, Li; Bowman, Howard; Barnard, Philip
2011-01-01
In humans, there is a trade-off between the need to respond optimally to the salient environmental stimuli and the need to meet our long-term goals. This implies that a system of salience sensitive control exists, which trades task-directed processing off against monitoring and responding to potentially high salience stimuli that are irrelevant to the current task. Much cognitive control research has attempted to understand these mechanisms using non-affective stimuli. However, recent research has emphasized the importance of emotions, which are a major factor in the prioritization of competing stimuli and in directing attention. While relatively mature theories of cognitive control exist for non-affective settings, exactly how emotions modulate cognitive processes is less well understood. The attentional blink (AB) task is a useful experimental paradigm to reveal the dynamics of both cognitive and affective control in humans. Hence, we have developed the glance-look model, which has replicated a broad profile of data on the semantic AB task and characterized how attentional deployment is modulated by emotion. Taking inspiration from Barnard's Interacting Cognitive Subsystems, the model relies on a distinction between two levels of meaning: implicational and propositional, which are supported by two corresponding mental subsystems: the glance and the look respectively. In our model, these two subsystems reflect the central engine of cognitive control and executive function. In particular, the interaction within the central engine dynamically establishes a task filter for salient stimuli using a neurobiologically inspired learning mechanism. In addition, the somatic contribution of emotional effects is modeled by a body-state subsystem. We argue that stimulus-driven interaction among these three subsystems governs the movement of control between them. The model also predicts attenuation effects and fringe awareness during the AB.
Impact of Energy Gain and Subsystem Characteristics on Fusion Propulsion Performance
NASA Technical Reports Server (NTRS)
Chakrabarti, S.; Schmidt, G. R.
2001-01-01
Rapid transport of large payloads and human crews throughout the solar system requires propulsion systems having very high specific impulse (I(sub sp) > 10(exp 4) to 10(exp 5) s). It also calls for systems with extremely low mass-power ratios (alpha < 10(exp -1) kg/kW). Such low alpha are beyond the reach of conventional power-limited propulsion, but may be attainable with fusion and other nuclear concepts that produce energy within the propellant. The magnitude of energy gain must be large enough to sustain the nuclear process while still providing a high jet power relative to the massive energy-intensive subsystems associated with these concepts. This paper evaluates the impact of energy gain and subsystem characteristics on alpha. Central to the analysis are general parameters that embody the essential features of any 'gain-limited' propulsion power balance. Results show that the gains required to achieve alpha = 10(exp -1) kg/kW with foreseeable technology range from approximately 100 to over 2000, which is three to five orders of magnitude greater than current fusion state of the arL Sensitivity analyses point to the parameters exerting the most influence for either: (1) lowering a and improving mission performance or (2) relaxing gain requirements and reducing demands on the fusion process. The greatest impact comes from reducing mass and increasing efficiency of the thruster and subsystems downstream of the fusion process. High relative gain, through enhanced fusion processes or more efficient drivers and processors, is also desirable. There is a benefit in improving driver and subsystem characteristics upstream of the fusion process, but it diminishes at relative gains > 100.
Solid freeform fabrication apparatus and methods
NASA Technical Reports Server (NTRS)
Taminger, Karen M. (Inventor); Watson, J. Kevin (Inventor); Hafley, Robert A. (Inventor); Petersen, Daniel D. (Inventor)
2007-01-01
An apparatus for formation of a three dimensional object comprising a sealed container; an electron beam subsystem capable of directing energy within said container; a positioning subsystem contained within said container; a wire feed subsystem contained within said container; an instrumentation subsystem electronically connected to said electron beam subsystem, positioning subsystem, and wire feed subsystem; and a power distribution subsystem electrically connected to said electron beam subsystem, positioning subsystem, wire feed subsystem, and said instrumentation subsystem.
NASA Technical Reports Server (NTRS)
Lu, Richard; Chan, Jeffrey
1994-01-01
The original design of the Student Mentored Advanced Research and Technology Satellite (SMARTSat) began in January of 1994. The mission adhered to the guidelines and constraints set forth by the Student Explorer Demonstration Initiative Proposal, which was sponsored by the Universities Space Research Association. This report represents a redesign of that original concept. The main differences include a higher orbit and a three axis stabilization system. Of course, these changes imparted significant effects upon the other subsystems. Outlined in this document are those modifications and it offers some new analyses as well. For each subsystem there is a brief description, followed by relevant design assumptions, a summary of conclusions, and finally all pertinent supporting data and graphs. Towards the end of the report. the important issue of cost is addressed as well. Whenever possible, parametric analyses were made.
Orbital Maneuvering system design evolution
NASA Technical Reports Server (NTRS)
Gibson, C.; Humphries, C.
1985-01-01
Preliminary design considerations and changes made in the baseline space shuttle orbital maneuvering system (OMS) to reduce cost and weight are detailed. The definition of initial subsystem requirements, trade studies, and design approaches are considered. Design features of the engine, its injector, combustion chamber, nozzle extension and bipropellant valve are illustrated and discussed. The current OMS consists of two identical pods that use nitrogen tetroxide (NTO) and monomethylhydrazine (MMH) propellants to provide 1000 ft/sec of delta velocity for a payload of 65,000 pounds. Major systems are pressurant gas storage and control, propellant storage supply and quantity measurement, and the rocket engine, which includes a bipropellant valve, an injector/thrust chamber, and a nozzle. The subsystem provides orbit insertion, circularization, and on orbit and deorbit capability for the shuttle orbiter.
Variable speed generator application on the MOD-5A 7.3 mW wind turbine generator
NASA Technical Reports Server (NTRS)
Barton, Robert S.
1995-01-01
This paper describes the application of a Scherbiustat type variable speed subsystem in the MOD-5A Wind Turbine Generator. As designed by General Electric Company, Advanced Energy Programs Department, under contract DEN3-153 with NASA Lewis Research Center and DOE, the MOD-5A utilizes the subsystem for both starting assistance in a motoring mode and generation in a controlled airgap torque mode. Reactive power control is also provided. The Scherbiustat type arrangement of a wound rotor machine with a cycloconverter in the rotor circuit was selected after an evaluation of variable speed technologies that followed a system evaluation of drivetrain cost and risk. The paper describes the evaluation factors considered, the results of the evaluations and summarizes operating strategy and performance simulations.
Shuttle infrared telescope facility (SIRTF) preliminary design study
NASA Technical Reports Server (NTRS)
1976-01-01
An overall picture of the SIRTF system is first presented, including the telescope, focal plane instruments, cryogen supply, shuttle and spacelab support subsystems, mechanical and data interfaces with the vehicles, ground support equipment, and system requirements. The optical, mechanical, and thermal characteristics of the telescope are then evaluated, followed by a description of the SIRTF internal stabilization subsystem and its interface with the IPS. Expected performance in the shuttle environment is considered. Tradeoff studies are described, including the Gregorian versus the Cassegrain telescope, aperture diameter tradeoff, a CCD versus an image dissector for the star tracker, the large ambient telescope versus the SIRTF, and a dedicated gimbal versus the IPS. Operations from integration through launch and recovery are also discussed and cost estimates for the program are presented.
NASA Technical Reports Server (NTRS)
1985-01-01
The results of detailed cost estimates and economic analysis performed on the updated Model 101 configuration of the general purpose Aft Cargo Carrier (ACC) are given. The objective of this economic analysis is to provide the National Aeronautics and Space Administration (NASA) with information on the economics of using the ACC on the Space Transportation System (STS). The detailed cost estimates for the ACC are presented by a work breakdown structure (WBS) to ensure that all elements of cost are considered in the economic analysis and related subsystem trades. Costs reported by WBS provide NASA with a basis for comparing competing designs and provide detailed cost information that can be used to forecast phase C/D planning for new projects or programs derived from preliminary conceptual design studies. The scope covers all STS and STS/ACC launch vehicle cost impacts for delivering payloads to a 160 NM low Earth orbit (LEO).
NASA Technical Reports Server (NTRS)
1985-01-01
Results of detailed cost estimates and economic analysis performed on the updated 201 configuration of the dedicated Aft Cargo Carrier (DACC) are given. The objective of this economic analysis is to provide the National Aeronautics and Space Administration (NASA) with information on the economics of using the DACC on the Space Transportation System (STS). The detailed cost estimates for the DACC are presented by a work breakdown structure (WBS) to ensure that all elements of cost are considered in the economic analysis and related subsystem trades. Costs reported by WBS provide NASA with a basis for comparing competing designs and provide detailed cost information that can be used to forecast phase C/D planning for new projects or programs derived from preliminary conceptual design studies. The scope covers all STS and STS/DACC launch vehicle cost impacts for delivering an orbital transfer vehicle to a 120 NM low Earth orbit (LEO).
NASA Astrophysics Data System (ADS)
Liu, Xiaomei; Li, Shengtao; Zhang, Kanjian
2017-08-01
In this paper, we solve an optimal control problem for a class of time-invariant switched stochastic systems with multi-switching times, where the objective is to minimise a cost functional with different costs defined on the states. In particular, we focus on problems in which a pre-specified sequence of active subsystems is given and the switching times are the only control variables. Based on the calculus of variation, we derive the gradient of the cost functional with respect to the switching times on an especially simple form, which can be directly used in gradient descent algorithms to locate the optimal switching instants. Finally, a numerical example is given, highlighting the validity of the proposed methodology.
Gallium arsenide solar array subsystem study
NASA Technical Reports Server (NTRS)
Miller, F. Q.
1982-01-01
The effects on life cycle costs of a number of technology areas are examined for a gallium arsenide space solar array. Four specific configurations were addressed: (1) a 250 KWe LEO mission - planer array; (2) a 250 KWe LEO mission - with concentration; (3) a 50 KWe GEO mission planer array; (4) a 50 KWe GEO mission - with concentration. For each configuration, a baseline system conceptual design was developed and the life cycle costs estimated in detail. The baseline system requirements and design technologies were then varied and their relationships to life cycle costs quantified. For example, the thermal characteristics of the baseline design are determined by the array materials and masses. The thermal characteristics in turn determine configuration, performance, and hence life cycle costs.
Guidelines for application of learning/cost improvement curves
NASA Technical Reports Server (NTRS)
Delionback, L. M.
1975-01-01
The differences between the terms learning curve and improvement curve are noted, as well as the differences between the Wright system and the Crawford system. Learning curve computational techniques were reviewed along with a method to arrive at a composite learning curve for a system given detail curves either by the functional techniques classification or simply categorized by subsystem. Techniques are discussed for determination of the theoretical first unit (TFU) cost using several of the currently accepted methods. Sometimes TFU cost is referred to as simply number one cost. A tabular presentation of the various learning curve slope values is given. A discussion of the various trends in the application of learning/improvement curves and an outlook for the future are presented.
More sense for less cents: Cost effective servicing of remote sensing satellites
NASA Technical Reports Server (NTRS)
Lee, Jeannie; Misencik, Tom; Robertson, Bill; Sliney, Jack
1993-01-01
This paper addresses the design considerations for Earth observation spacecraft bus and payload subsystems such that cost-effective spacecraft maintainability is enhanced through optimized reliability and the application of robotic on-orbit support. In the past, for most satellites, maintainability has been associated with the clever application of telemetry reconfiguration and the use of redundant systems as necessary over the life cycle of the spacecraft. This presentation addresses the opportunities and challenges of leveraging the extensive work already accomplished in the development of on-orbit servicing technologies.
Evolutionary space platform concept study. Volume 2, part A: SASP special emphasis trade studies
NASA Technical Reports Server (NTRS)
1982-01-01
Efforts are in progress to define an approach to provide a simple and cost effective solution to the problem of long duration space flight. This approach involves a Space Platform in low Earth orbit, which can be tended by the Space Shuttle and which will provide, for extended periods of time, stability, utilities and access for a variety of replaceable payloads. The feasibility of an evolutionary space system which would cost effectively support unmanned payloads in groups, using a Space Platform which provides centralized basic subsystems is addressed.
Coastal Research Imaging Spectrometer
NASA Technical Reports Server (NTRS)
Lucey, Paul G.; Williams, Timothy; Horton, Keith A.
2004-01-01
The Coastal Research Imaging Spectrometer (CRIS) is an airborne remote sensing system designed specifically for research on the physical, chemical, and biological characteristics of coastal waters. The CRIS includes a visible-light hyperspectral imaging subsystem for measuring the color of water, which contains information on the biota, sediment, and nutrient contents of the water. The CRIS also includes an infrared imaging subsystem, which provides information on the temperature of the water. The combination of measurements enables investigation of biological effects of both natural and artificial flows of water from land into the ocean, including diffuse and point-source flows that may contain biological and/or chemical pollutants. Temperature is an important element of such measurements because temperature contrasts can often be used to distinguish among flows from different sources: for example, a sewage outflow could manifest itself in spectral images as a local high-temperature anomaly. Both the visible and infrared subsystems scan in pushbroom mode: that is, an aircraft carrying the system moves along a ground track, the system is aimed downward, and image data are acquired in across-track linear arrays of pixels. Both subsystems operate at a frame rate of 30 Hz. The infrared and visible-light optics are adjusted so that both subsystems are aimed at the same moving swath, which has across-track angular width of 15 . Data from the infrared and visible imaging subsystems are stored in the same file along with aircraft- position data acquired by a Global Positioning System receiver. The combination of the three sets of data is used to construct infrared and hyperspectral maps of scanned areas (see figure). The visible subsystem is based on a grating spectrograph and a rapid-readout charge-coupled-device camera. Images of the swatch are acquired in 256 spectral bands at wavelengths from 400 to 800 nm. The infrared subsystem, which is sensitive in a single wavelength band of 8 to 10 m, is based on a focal-plane array of HgCdTe photodetectors that are cooled to an operating temperature of 77 K by use of a closed-Stirling-cycle mechanical cooler. The nonuniformities of the HgCdTe photodetector array are small enough that the raw pixel data from the infrared subsystem can be used to recognize temperature differences on the order of 1 C. By use of a built-in blackbody calibration source that can be switched into the field of view, one can obtain bias and gain offset terms for individual pixels, making it possible to offset the effects of nonuniformities sufficiently to enable the measurement of temperature differences as small as 0.1 C.
Solar thermal program summary. Volume 1: Overview, fiscal year 1988
NASA Astrophysics Data System (ADS)
1989-02-01
The goal of the solar thermal program is to improve overall solar thermal systems performance and provide cost-effective energy options that are strategically secure and environmentally benign. Major research activities include energy collection technology, energy conversion technology, and systems and applications technology for both CR and DR systems. This research is being conducted through research laboratories in close coordination with the solar thermal industry, utilities companies, and universities. The Solar Thermal Technology Program is pursuing the development of critical components and subsystems for improved energy collection and conversion devices. This development follows two basic paths: for CR systems, critical components include stretched membrane heliostats, direct absorption receivers (DARs), and transport subsystems for molten salt heat transfer fluids. These components offer the potential for a significant reduction in system costs; and for DR systems, critical components include stretched membrane dishes, reflux receivers, and Stirling engines. These components will significantly increase system reliability and efficiency, which will reduce costs. The major thrust of the program is to provide electric power. However, there is an increasing interest in the use of concentrated solar energy for applications such as detoxifying hazardous wastes and developing high-value transportable fuels. These potential uses of highly concentrated solar energy still require additional experiments to prove concept feasibility. The program goal of economically competitive energy reduction from solar thermal systems is being cooperatively addressed by industry and government.
A systems engineering analysis of three-point and four-point wind turbine drivetrain configurations
Guo, Yi; Parsons, Tyler; Dykes, Katherine; ...
2016-08-24
This study compares the impact of drivetrain configuration on the mass and capital cost of a series of wind turbines ranging from 1.5 MW to 5.0 MW power ratings for both land-based and offshore applications. The analysis is performed with a new physics-based drivetrain analysis and sizing tool, Drive Systems Engineering (DriveSE), which is part of the Wind-Plant Integrated System Design & Engineering Model. DriveSE uses physics-based relationships to size all major drivetrain components according to given rotor loads simulated based on International Electrotechnical Commission design load cases. The model's sensitivity to input loads that contain a high degree ofmore » variability was analyzed. Aeroelastic simulations are used to calculate the rotor forces and moments imposed on the drivetrain for each turbine design. DriveSE is then used to size all of the major drivetrain components for each turbine for both three-point and four-point configurations. The simulation results quantify the trade-offs in mass and component costs for the different configurations. On average, a 16.7% decrease in total nacelle mass can be achieved when using a three-point drivetrain configuration, resulting in a 3.5% reduction in turbine capital cost. This analysis is driven by extreme loads and does not consider fatigue. Thus, the effects of configuration choices on reliability and serviceability are not captured. Furthermore, a first order estimate of the sizing, dimensioning and costing of major drivetrain components are made which can be used in larger system studies which consider trade-offs between subsystems such as the rotor, drivetrain and tower.« less
A systems engineering analysis of three-point and four-point wind turbine drivetrain configurations
DOE Office of Scientific and Technical Information (OSTI.GOV)
Guo, Yi; Parsons, Tyler; Dykes, Katherine
This study compares the impact of drivetrain configuration on the mass and capital cost of a series of wind turbines ranging from 1.5 MW to 5.0 MW power ratings for both land-based and offshore applications. The analysis is performed with a new physics-based drivetrain analysis and sizing tool, Drive Systems Engineering (DriveSE), which is part of the Wind-Plant Integrated System Design & Engineering Model. DriveSE uses physics-based relationships to size all major drivetrain components according to given rotor loads simulated based on International Electrotechnical Commission design load cases. The model's sensitivity to input loads that contain a high degree ofmore » variability was analyzed. Aeroelastic simulations are used to calculate the rotor forces and moments imposed on the drivetrain for each turbine design. DriveSE is then used to size all of the major drivetrain components for each turbine for both three-point and four-point configurations. The simulation results quantify the trade-offs in mass and component costs for the different configurations. On average, a 16.7% decrease in total nacelle mass can be achieved when using a three-point drivetrain configuration, resulting in a 3.5% reduction in turbine capital cost. This analysis is driven by extreme loads and does not consider fatigue. Thus, the effects of configuration choices on reliability and serviceability are not captured. Furthermore, a first order estimate of the sizing, dimensioning and costing of major drivetrain components are made which can be used in larger system studies which consider trade-offs between subsystems such as the rotor, drivetrain and tower.« less
Neuropathophysiology of functional gastrointestinal disorders
Wood, Jackie D
2007-01-01
The investigative evidence and emerging concepts in neurogastroenterology implicate dysfunctions at the levels of the enteric and central nervous systems as underlying causes of the prominent symptoms of many of the functional gastrointestinal disorders. Neurogastroenterological research aims for improved understanding of the physiology and pathophysiology of the digestive subsystems from which the arrays of functional symptoms emerge. The key subsystems for defecation-related symptoms and visceral hyper-sensitivity are the intestinal secretory glands, the musculature and the nervous system that controls and integrates their activity. Abdominal pain and discomfort arising from these systems adds the dimension of sensory neurophysiology. This review details current concepts for the underlying pathophysiology in terms of the physiology of intestinal secretion, motility, nervous control, sensing function, immuno-neural communication and the brain-gut axis. PMID:17457962
Automated assessment of mobility in bedridden patients.
Bennett, Stephanie; Goubran, Rafik; Rockwood, Kenneth; Knoefel, Frank
2013-01-01
Immobility in older patients is a costly problem for both patients and healthcare workers. The Hierarchical Assessment of Balance and Mobility (HABAM) is a clinical tool able to assess immobile patients and predict morbidity, yet could become more reliable and informative through automation. This paper proposes an algorithm to automatically determine which of three enacted HABAM scores (associated with bedridden patients) had been performed by volunteers. A laptop was used to gather pressure data from three mats placed on a standard hospital bed frame while five volunteers performed three enactments each. A system of algorithms was created, consisting of three subsystems. The first subsystem used mattress data to calculate individual sensor sums and eliminate the weight of the mattress. The second subsystem established a baseline pressure reading for each volunteer and used percentage change to identify and distinguish between two enactments. The third subsystem used calculated weight distribution ratios to determine if the data represented the remaining enactment. The system was tested for accuracy by inputting the volunteer data and recording the assessment output (a score per data set). The system identified 13 of 15 sets of volunteer data as expected. Examination of these results indicated that the two sets of data were not misidentified; rather, the volunteers had made mistakes in performance. These results suggest that this system of algorithms is effective in distinguishing between the three HABAM score enactments examined here, and emphasizes the potential for pervasive computing to improve traditional healthcare.
Recent Advances and Perspectives on Nonadiabatic Mixed Quantum-Classical Dynamics.
Crespo-Otero, Rachel; Barbatti, Mario
2018-05-16
Nonadiabatic mixed quantum-classical (NA-MQC) dynamics methods form a class of computational theoretical approaches in quantum chemistry tailored to investigate the time evolution of nonadiabatic phenomena in molecules and supramolecular assemblies. NA-MQC is characterized by a partition of the molecular system into two subsystems: one to be treated quantum mechanically (usually but not restricted to electrons) and another to be dealt with classically (nuclei). The two subsystems are connected through nonadiabatic couplings terms to enforce self-consistency. A local approximation underlies the classical subsystem, implying that direct dynamics can be simulated, without needing precomputed potential energy surfaces. The NA-MQC split allows reducing computational costs, enabling the treatment of realistic molecular systems in diverse fields. Starting from the three most well-established methods-mean-field Ehrenfest, trajectory surface hopping, and multiple spawning-this review focuses on the NA-MQC dynamics methods and programs developed in the last 10 years. It stresses the relations between approaches and their domains of application. The electronic structure methods most commonly used together with NA-MQC dynamics are reviewed as well. The accuracy and precision of NA-MQC simulations are critically discussed, and general guidelines to choose an adequate method for each application are delivered.
Pathfinder Technology Demonstrator: GlobalStar Testing and Results
NASA Technical Reports Server (NTRS)
Kuroda, Vanessa; Limes, Gregory L.; Han, Shi Lei; Hanson, John Eric; Christa, Scott E.
2016-01-01
The communications subsystem of a spacecraft is typically a SWaP (size, weight, and power) intensive subsystem in a SWaP constrained environment such as a CubeSat. Use of a satellite-based communication system, such as GlobalStars duplex GSP-1720 radio is a low SWaP potentially game-changing low-cost communication subsystem solution that was evaluated for feasibility for the NASA Pathfinder Technology Demonstrator (PTD) project. The PTD project is a series of 6U CubeSat missions to flight demonstrate and characterize novel small satellite payloads in low Earth orbit. GlobalStar is a low Earth orbit satellite constellation for satellite phone and low-speed data communications, and the GSP-1720 is their single board duplex radio most commonly used in satellite phones and shipment tracking devices. The PTD project tested the GSP-1720 to characterize its viability for flight using NASA GEVS (General Environmental Verification Standard) vibration and thermal vacuum levels, as well as testing the uplink-downlink connectivity, data throughput, and file transfer capabilities. This presentation will present the results of the environmental and capability testing of the GSP-1720 performed at NASA Ames Research Center, as well as the viability for CubeSat use in LEO.
Narayanan, Vignesh; Jagannathan, Sarangapani
2017-09-07
In this paper, a distributed control scheme for an interconnected system composed of uncertain input affine nonlinear subsystems with event triggered state feedback is presented by using a novel hybrid learning scheme-based approximate dynamic programming with online exploration. First, an approximate solution to the Hamilton-Jacobi-Bellman equation is generated with event sampled neural network (NN) approximation and subsequently, a near optimal control policy for each subsystem is derived. Artificial NNs are utilized as function approximators to develop a suite of identifiers and learn the dynamics of each subsystem. The NN weight tuning rules for the identifier and event-triggering condition are derived using Lyapunov stability theory. Taking into account, the effects of NN approximation of system dynamics and boot-strapping, a novel NN weight update is presented to approximate the optimal value function. Finally, a novel strategy to incorporate exploration in online control framework, using identifiers, is introduced to reduce the overall cost at the expense of additional computations during the initial online learning phase. System states and the NN weight estimation errors are regulated and local uniformly ultimately bounded results are achieved. The analytical results are substantiated using simulation studies.
Landsat-1 and Landsat-2 flight evaluation
NASA Technical Reports Server (NTRS)
1975-01-01
The flight performance of Landsat 1 and Landsat 2 is analyzed. Flight operations of the satellites are briefly summarized. Other topics discussed include: orbital parameters; power subsystem; attitude control subsystem; command/clock subsystem; telemetry subsystem; orbit adjust subsystem; magnetic moment compensating assembly; unified s-band/premodulation processor; electrical interface subsystem; thermal subsystem; narrowband tape recorders; wideband telemetry subsystem; attitude measurement sensor; wideband video tape recorders; return beam vidicon; multispectral scanner subsystem; and data collection subsystem.
GRYPHON: Air launched space booster
NASA Technical Reports Server (NTRS)
1993-01-01
The project chosen for the winter semester Aero 483 class was the design of a next generation Air Launched Space Booster. Based on Orbital Sciences Corporation's Pegasus concept, the goal of Aero 483 was to design a 500,000 pound air launched space booster capable of delivering 17,000 pounds of payload to Low Earth Orbit and 8,000 pounds of payload to Geosynchronous Earth Orbit. The resulting launch vehicle was named the Gryphon. The class of forty senior aerospace engineering students was broken down into eight interdependent groups. Each group was assigned a subsystem or responsibility which then became their field of specialization. Spacecraft Integration was responsible for ensuring compatibility between subsystems. This group kept up to date on subsystem redesigns and informed those parties affected by the changes, monitored the vehicle's overall weight and dimensions, and calculated the mass properties of the booster. This group also performed the cost/profitability analysis of the Gryphon and obtained cost data for competing launch systems. The Mission Analysis Group was assigned the task of determining proper orbits, calculating the vehicle's flight trajectory for those orbits, and determining the aerodynamic characteristics of the vehicle. The Propulsion Group chose the engines that were best suited to the mission. This group also set the staging configurations for those engines and designed the tanks and fuel feed system. The commercial satellite market, dimensions and weights of typical satellites, and method of deploying satellites was determined by the Payloads Group. In addition, Payloads identified possible resupply packages for Space Station Freedom and identified those packages that were compatible with the Gryphon. The guidance, navigation, and control subsystems were designed by the Mission Control Group. This group identified required tracking hardware, communications hardware telemetry systems, and ground sites for the location of the Gryphon's mission control center. The Structures group was responsible for ensuring the structural integrity of the vehicle. Their designs included the payload shroud, payload support structure, exterior hull and engine support struts. The Gryphon's power requirements were determined by the Power/Thermal/Attitude Control Group. This group then selected suitable batteries and other components to meet these requirements. The group also designed heat shielding and cooling systems to ensure subsystem performance. In addition to these responsibilities this group designed the attitude control methods and RCS components for the vehicle. The Aircraft Integration Group was responsible for all aspects of the booster aircraft connection. This included the design of the connection structure and the drop mechanism. This group also designed the vehicle assembly facility and identified possible ground bases for the plane.
GRYPHON: Air launched space booster
NASA Astrophysics Data System (ADS)
1993-06-01
The project chosen for the winter semester Aero 483 class was the design of a next generation Air Launched Space Booster. Based on Orbital Sciences Corporation's Pegasus concept, the goal of Aero 483 was to design a 500,000 pound air launched space booster capable of delivering 17,000 pounds of payload to Low Earth Orbit and 8,000 pounds of payload to Geosynchronous Earth Orbit. The resulting launch vehicle was named the Gryphon. The class of forty senior aerospace engineering students was broken down into eight interdependent groups. Each group was assigned a subsystem or responsibility which then became their field of specialization. Spacecraft Integration was responsible for ensuring compatibility between subsystems. This group kept up to date on subsystem redesigns and informed those parties affected by the changes, monitored the vehicle's overall weight and dimensions, and calculated the mass properties of the booster. This group also performed the cost/profitability analysis of the Gryphon and obtained cost data for competing launch systems. The Mission Analysis Group was assigned the task of determining proper orbits, calculating the vehicle's flight trajectory for those orbits, and determining the aerodynamic characteristics of the vehicle. The Propulsion Group chose the engines that were best suited to the mission. This group also set the staging configurations for those engines and designed the tanks and fuel feed system. The commercial satellite market, dimensions and weights of typical satellites, and method of deploying satellites was determined by the Payloads Group. In addition, Payloads identified possible resupply packages for Space Station Freedom and identified those packages that were compatible with the Gryphon. The guidance, navigation, and control subsystems were designed by the Mission Control Group. This group identified required tracking hardware, communications hardware telemetry systems, and ground sites for the location of the Gryphon's mission control center. The Structures group was responsible for ensuring the structural integrity of the vehicle. Their designs included the payload shroud, payload support structure, exterior hull and engine support struts. The Gryphon's power requirements were determined by the Power/Thermal/Attitude Control Group.
REUSABLE PROPULSION ARCHITECTURE FOR SUSTAINABLE LOW-COST ACCESS TO SPACE
NASA Technical Reports Server (NTRS)
Bonometti, J. A.; Dankanich, J. W.; Frame, K. L.
2005-01-01
The primary obstacle to any space-based mission is, and has always been, the cost of access to space. Even with impressive efforts toward reusability, no system has come close to lowering the cost a significant amount. It is postulated here, that architectural innovation is necessary to make reusability feasible, not incremental subsystem changes. This paper shows two architectural approaches of reusability that merit further study investments. Both #inherently# have performance increases and cost advantages to make affordable access to space a near term reality. A rocket launched from a subsonic aircraft (specifically the Crossbow methodology) and a momentum exchange tether, reboosted by electrodynamics, offer possibilities of substantial reductions in the total transportation architecture mass - making access-to-space cost-effective. They also offer intangible benefits that reduce risk or offer large growth potential. The cost analysis indicates that approximately a 50% savings is obtained using today#s aerospace materials and practices.
Analyzing the requirements for mass production of small wind turbine generators
NASA Astrophysics Data System (ADS)
Anuskiewicz, T.; Asmussen, J.; Frankenfield, O.
Mass producibility of small wind turbine generators to give manufacturers design and cost data for profitable production operations is discussed. A 15 kW wind turbine generator for production in annual volumes from 1,000 to 50,000 units is discussed. Methodology to cost the systems effectively is explained. The process estimate sequence followed is outlined with emphasis on the process estimate sheets compiled for each component and subsystem. These data enabled analysts to develop cost breakdown profiles crucial in manufacturing decision-making. The appraisal also led to various design recommendations including replacement of aluminum towers with cost effective carbon steel towers. Extensive cost information is supplied in tables covering subassemblies, capital requirements, and levelized energy costs. The physical layout of the plant is depicted to guide manufacturers in taking advantage of the growing business opportunity now offered in conjunction with the national need for energy development.
Why projects often fail even with high cost contingencies
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kujawski, Edouard
2002-02-28
In this note we assume that the individual risks have been adequately quantified and the total project cost contingency adequately computed to ensure an agreed-to probability or confidence level that the total project cost estimate will not be exceeded. But even projects that implement such a process are likely to result in significant cost overruns and/or project failure if the project manager allocates the contingencies to the individual subsystems. The intuitive and mathematically valid solution is to maintain a project-wide contingency and to distribute it to the individual risks on an as-needed basis. Such an approach ensures cost-efficient risk management,more » and projects that implement it are more likely to succeed and to cost less. We illustrate these ideas using a simplified project with two independent risks. The formulation can readily be extended to multiple risks.« less
Man power/cost estimation model: Automated planetary projects
NASA Technical Reports Server (NTRS)
Kitchen, L. D.
1975-01-01
A manpower/cost estimation model is developed which is based on a detailed level of financial analysis of over 30 million raw data points which are then compacted by more than three orders of magnitude to the level at which the model is applicable. The major parameter of expenditure is manpower (specifically direct labor hours) for all spacecraft subsystem and technical support categories. The resultant model is able to provide a mean absolute error of less than fifteen percent for the eight programs comprising the model data base. The model includes cost saving inheritance factors, broken down in four levels, for estimating follow-on type programs where hardware and design inheritance are evident or expected.
LANDSAT-1 flight evaluation report
NASA Technical Reports Server (NTRS)
1975-01-01
Flight performance analysis for the tenth quarter of operation orbit 11467 to 12745 of LANDSAT 1 are presented. Payload subsystems discussed include: power subsystem; attitude control subsystem; telemetry subsystem; electrical interface subsystem; narrowband tape recorders; wideband telemetry subsystem; return beam vidicon subsystem; multispectral scanner subsystem; and data collection system.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Olszewski, M.
The U.S. Department of Energy (DOE) and the U.S. Council for Automotive Research (composed of automakers Ford, General Motors, and Chrysler) announced in January 2002 a new cooperative research effort. Known as FreedomCAR (derived from 'Freedom' and 'Cooperative Automotive Research'), it represents DOE's commitment to developing public/private partnerships to fund high-risk, high-payoff research into advanced automotive technologies. Efficient fuel cell technology, which uses hydrogen to power automobiles without air pollution, is a very promising pathway to achieve the ultimate vision. The new partnership replaces and builds upon the Partnership for a New Generation of Vehicles initiative that ran from 1993more » through 2001. The Advanced Power Electronics and Electric Machines (APEEM) subprogram within the Vehicle Technologies Program provides support and guidance for many cutting-edge automotive technologies now under development. Research is focused on understanding and improving the way the various new components of tomorrow's automobiles will function as a unified system to improve fuel efficiency. In supporting the development of hybrid propulsion systems, the APEEM effort has enabled the development of technologies that will significantly improve advanced vehicle efficiency, costs, and fuel economy. The APEEM subprogram supports the efforts of the FreedomCAR and Fuel Partnership through a three-phase approach intended to: (1) identify overall propulsion and vehicle-related needs by analyzing programmatic goals and reviewing industry's recommendations and requirements and then develop the appropriate technical targets for systems, subsystems, and component research and development activities; (2) develop and validate individual subsystems and components, including electric motors, and power electronics; and (3) determine how well the components and subsystems work together in a vehicle environment or as a complete propulsion system and whether the efficiency and performance targets at the vehicle level have been achieved. The research performed under this subprogram will help remove technical and cost barriers to enable the development of technology for use in such advanced vehicles as hybrid electric vehicles (HEVs), plug-in HEVs, and fuel-cell-powered automobiles that meet the goals of the Vehicle Technologies Program. A key element in making HEVs practical is providing an affordable electric traction drive system. This will require attaining weight, volume, and cost targets for the power electronics and electrical machines subsystems of the traction drive system. Areas of development include these: (1) novel traction motor designs that result in increased power density and lower cost; (2) inverter technologies involving new topologies to achieve higher efficiency and the ability to accommodate higher-temperature environments; (3) converter concepts that employ means of reducing the component count and integrating functionality to decrease size, weight, and cost; (4) more effective thermal control and packaging technologies; and (5) integrated motor/inverter concepts. The Oak Ridge National Laboratory's (ORNL's) Power Electronics and Electric Machinery Research Center conducts fundamental research, evaluates hardware, and assists in the technical direction of the DOE Vehicle Technologies Program, APEEM subprogram. In this role, ORNL serves on the FreedomCAR Electrical and Electronics Technical Team, evaluates proposals for DOE, and lends its technological expertise to the direction of projects and evaluation of developing technologies.« less
Space station needs, attributes and architectural options. Volume 1: Executive summary NASA
NASA Technical Reports Server (NTRS)
1983-01-01
The uses alignment plan was implemented. The existing data bank was used to define a large number of station requirements. Ten to 20 valid mission scenarios were developed. Architectural options as they are influenced by communications operations, subsystem evolvability, and required technology growth are defined. Costing of evolutionary concepts, alternative approaches, and options, was based on minimum design details.
Fault Tolerant Optimal Control.
1982-08-01
subsystem is modelled by deterministic or stochastic finite-dimensional vector differential or difference equations. The parameters of these equations...is no partial differential equation that must be solved. Thus we can sidestep the inability to solve the Bellman equation for control problems with x...transition models and cost functionals can be reduced to the search for solutions of nonlinear partial differential equations using ’verification
Evaluation philosophy for shuttle launched payloads
NASA Technical Reports Server (NTRS)
Heuser, R. E.
1975-01-01
Some approaches to space-shuttle payload evaluation are examined. Issues considered include subsystem replacement in low-cost modular spacecraft (LCMS), validation of spacelab payloads, the use of standard components in shuttle-era spacecraft, effects of shuttle-induced environments on payloads, and crew safety. The LCMS is described, and goals are discussed for its evaluation program. Concepts regarding how the evaluation should proceed are considered.
NASA Technical Reports Server (NTRS)
1974-01-01
The SERT C (Space Electric Rocket Test - C) project study defines a spacecraft mission that would demonstrate the technology readiness of ion thruster systems for primary propulsion and station keeping applications. As a low cost precursor, SERT C develops the components and systems required for subsequent Solar Electric Propulsion (SEP) applications. The SERT C mission requirements and preliminary spacecraft and subsystem design are described.
ERIC Educational Resources Information Center
Cronshey, Raymond W.; Dunklau, M. William
This booklet describes the Daily Production Reports subsystem of the School Food Management System, a computer program package developed as one part of a family of educational management systems. The Daily Production Reports system produces two major types of reports on a daily basis. Business Analysis Reports display all food service costs, as…
Controlling Flows Of Two Ingredients For Spraying
NASA Technical Reports Server (NTRS)
Chandler, Huel H.
1995-01-01
Closed-loop servo control subsystem incorporated, as modification, into system controlling flows of two ingredients mixed and sprayed to form thermally insulating foams on large tanks. Provides steady flows at specified rates. Foams produced smoother and of higher quality. Continued use of system results in substantial reduction in cost stemming from close control of application of foam and consequent reduced use of material.
Research and Development of Rapid Design Systems for Aerospace Structure
NASA Technical Reports Server (NTRS)
Schaeffer, Harry G.
1999-01-01
This report describes the results of research activities associated with the development of rapid design systems for aerospace structures in support of the Intelligent Synthesis Environment (ISE). The specific subsystems investigated were the interface between model assembly and analysis; and, the high performance NASA GPS equation solver software system in the Windows NT environment on low cost high-performance PCs.
A Low Cost Spacecraft Architecture for Robotic Lunar Exploration Projects
NASA Technical Reports Server (NTRS)
Lemke, Lawrence G.; Gonzales, Andrew A.
2006-01-01
A program of frequent, capable, but affordable lunar robotic missions prior to return of humans to the moon can contribute to the Vision for Space Exploration (VSE) NASA is tasked to execute. The Lunar Reconnaissance Orbiter (LRO) and its secondary payload are scheduled to orbit the moon, and impact it, respectively, in 2008. It is expected that the sequence of missions occurring for approximately the decade after 2008 will place an increasing emphasis on soft landed payloads. These missions are requited to explore intrinsic characteristics of the moon, such as hydrogen distribution in the regolith, and levitated dust, to demonstrate the ability to access and process in-situ resources, and to demonstrate functions critical to supporting human presence, such as automated precision navigation and landing. Additional factors governing the design of spacecraft to accomplish this diverse set of objectives are: operating within a relatively modest funding profile, the need tb visit multiple sites (both polar and equatorial) repeatedly, and to use the current generation of launch vehicles. In the US, this implies use of the Evolved Expendable Launch Vehicles, or EELVs, although this design philosophy may be extended to launch vehicles of other nations, as well. Many of these factors are seemingly inconsistent with each other. For example, the cost of a spacecraft usually increases with mass; therefore the desire to fly frequent, modestly priced spacecraft seems to imply small spacecraft (< 1 Mt, injected mass). On the other hand, the smallest of the EELVs will inject approx. 3 Mt. on a Trans Lunar Injection (TLI) trajectory md would therefore be wasteful or launching a single, small spacecraft. Increasing the technical capability of a spacecraft (such as autonomous navigation and soft landing) also usually increases cost. A strategy for spacecraft design that meets these conflicting requirements is presented. Taken together, spacecraft structure and propulsion subsystems constitute the majority of spacecraft mass; saving development and integration cost on these elements is critical to controlling cost. Therefore, a low cost, modular design for spacecraft structure and propulsion subsystems is presented which may be easily scaled up or down for either insertion into lunar orbit or braking for landing on the lunar surface. In order to effectively use the approx.3 Mt mass-to-TLI of the EELV, two low cost spacecraft will be manifested on the same launch. One spacecraft will be located on top of the other for launch and the two will have to be released in sequence in order to achieve all mission objectives. The two spacecraft could both be landers, both orbiters, or one lander and one orbiter. In order to achieve mass efficiency, the body of the spacecraft will serve the dual purposes of carrying launch loads and providing attachment points for all the spacecraft subsystems. In order to avoid unaffordable technology development costs, small liquid propulsion components and autonomous, scene-matching navigation cameras may be adapted from military missile programs in order to execute precision soft landings.
Improvement of Automated POST Case Success Rate Using Support Vector Machines
NASA Technical Reports Server (NTRS)
Zwack, Mathew R.; Dees, Patrick D.
2017-01-01
During early conceptual design of complex systems, concept down selection can have a large impact upon program life-cycle cost. Therefore, any concepts selected during early design will inherently commit program costs and affect the overall probability of program success. For this reason it is important to consider as large a design space as possible in order to better inform the down selection process. For conceptual design of launch vehicles, trajectory analysis and optimization often presents the largest obstacle to evaluating large trade spaces. This is due to the sensitivity of the trajectory discipline to changes in all other aspects of the vehicle design. Small deltas in the performance of other subsystems can result in relatively large fluctuations in the ascent trajectory because the solution space is non-linear and multi-modal. In order to help capture large design spaces for new launch vehicles, the authors have performed previous work seeking to automate the execution of the industry standard tool, Program to Optimize Simulated Trajectories (POST). This work initially focused on implementation of analyst heuristics to enable closure of cases in an automated fashion, with the goal of applying the concepts of design of experiments (DOE) and surrogate modeling to enable near instantaneous throughput of vehicle cases.3 As noted in [4] work was then completed to improve the DOE process by utilizing a graph theory based approach to connect similar design points.
Multiple-Path-Length Optical Absorbance Cell
NASA Technical Reports Server (NTRS)
2001-01-01
An optical absorbance cell that offers a selection of multiple optical path lengths has been developed as part of a portable spectrometric instrument that measures absorption spectra of small samples of water and that costs less than does a conventional, non-portable laboratory spectrometer. The instrument is intended, more specifically, for use in studying colored dissolved organic matter (CDOM) in seawater, especially in coastal regions. Accurate characterization of CDOM is necessary for building bio-optical mathematical models of seawater. The multiple path lengths of the absorption cell afford a wide range of sensitivity needed for measuring the optical absorbances associated with the wide range of concentrations of CDOM observed in nature. The instrument operates in the wavelength range of 370 to 725 nm. The major subsystems of the instrument (see figure) include a color-balanced light source; the absorption cell; a peristaltic pump; a high-precision, low-noise fiber optic spectrometer; and a laptop or other personal computer. A fiber-optic cable transmits light from the source to the absorption cell. Other optical fibers transmit light from the absorption cell to the spectrometer,
Portable nucleic acid thermocyclers.
Almassian, David R; Cockrell, Lisa M; Nelson, William M
2013-11-21
A nucleic acid thermal cycler is considered to be portable if it is under ten pounds, easily carried by one individual, and battery powered. Nucleic acid amplification includes both polymerase chain reaction (e.g. PCR, RT-PCR) and isothermal amplification (e.g. RPA, HDA, LAMP, NASBA, RCA, ICAN, SMART, SDA). There are valuable applications for portable nucleic acid thermocyclers in fields that include clinical diagnostics, biothreat detection, and veterinary testing. A system that is portable allows for the distributed detection of targets at the point of care and a reduction of the time from sample to answer. The designer of a portable nucleic acid thermocycler must carefully consider both thermal control and the detection of amplification. In addition to thermal control and detection, the designer may consider the integration of a sample preparation subsystem with the nucleic acid thermocycler. There are a variety of technologies that can achieve accurate thermal control and the detection of nucleic acid amplification. Important evaluation criteria for each technology include maturity, power requirements, cost, sensitivity, speed, and manufacturability. Ultimately the needs of a particular market will lead to user requirements that drive the decision between available technologies.
Master plan for REIS implementation. Final report
DOE Office of Scientific and Technical Information (OSTI.GOV)
Knobloch, P.C.
1974-08-01
Implementation requirements of the regional energy information system (REIS) and provision of a brief cost/benefit analysis of the proposed system are discussed. Divided into four sectors (problems, requirements, the present system, and the proposed implementation of REIS), the development of a demonstration data base, its implementation and that of the regional input-output model as a tool for decision makers are subjects of the report. The accounting subsystem and energy flow network model are two main components; the need to identify specific problems, to gather information on source, energy type, location, use, time with cross classification, the structure of REIS withmore » parameter subsystem, and a description of the study area (N. E. Minnesota) are included. Five energy-producing and 76 energy-using sectors are specified, with energy classification and forms included. (GRA)« less
Buffer thermal energy storage for a solar thermal powered 1-MW sub e electrical plant
NASA Astrophysics Data System (ADS)
Polzien, R. E.
The application of a latent heat thermal energy buffer storage (TEBS) subsystem to the small community solar thermal power experiment (SCSE) is discussed. The SCSE is a 1-MW sub e solar thermal electric plant consisting of multiple paraboloidal concentrators with an organic Rankine cycle power conversion unit mounted at the focus of each concentrator. Objective of the TEBS is to minimize plant shutdowns during intermittent cloud coverage thereby improving life expectancy of major subsystems. An SCSE plant performance model is used with time varying insolation to show that 70 to 80 percent of the potential engine shutdowns may be averted with the TEBS system. Parametric variation of engine life dependency on start/stop cycles shows the potential for a 4 percent reduction in levelized bus bar energy cost using TEBS.
Fruit Sorting Using Fuzzy Logic Techniques
NASA Astrophysics Data System (ADS)
Elamvazuthi, Irraivan; Sinnadurai, Rajendran; Aftab Ahmed Khan, Mohamed Khan; Vasant, Pandian
2009-08-01
Fruit and vegetables market is getting highly selective, requiring their suppliers to distribute the goods according to very strict standards of quality and presentation. In the last years, a number of fruit sorting and grading systems have appeared to fulfill the needs of the fruit processing industry. However, most of them are overly complex and too costly for the small and medium scale industry (SMIs) in Malaysia. In order to address these shortcomings, a prototype machine was developed by integrating the fruit sorting, labeling and packing processes. To realise the prototype, many design issues were dealt with. Special attention is paid to the electronic weighing sub-system for measuring weight, and the opto-electronic sub-system for determining the height and width of the fruits. Specifically, this paper discusses the application of fuzzy logic techniques in the sorting process.
The Study and Implementation of Text-to-Speech System for Agricultural Information
NASA Astrophysics Data System (ADS)
Zheng, Huoguo; Hu, Haiyan; Liu, Shihong; Meng, Hong
The Broadcast and Television coverage has increased to more than 98% in china. Information services by radio have wide coverage, low cost, easy-to-grass-roots farmers to accept etc. characteristics. In order to play the better role of broadcast information service, as well as aim at the problem of lack of information resource in rural, we R & D the text-to-speech system. The system includes two parts, software and hardware device, both of them can translate text into audio file. The software subsystem was implemented basic on third-part middleware, and the hardware subsystem was realized with microelectronics technology. Results indicate that the hardware is better than software. The system has been applied in huailai city hebei province, which has conversed more than 8000 audio files as programming materials for the local radio station.
Robust nonlinear variable selective control for networked systems
NASA Astrophysics Data System (ADS)
Rahmani, Behrooz
2016-10-01
This paper is concerned with the networked control of a class of uncertain nonlinear systems. In this way, Takagi-Sugeno (T-S) fuzzy modelling is used to extend the previously proposed variable selective control (VSC) methodology to nonlinear systems. This extension is based upon the decomposition of the nonlinear system to a set of fuzzy-blended locally linearised subsystems and further application of the VSC methodology to each subsystem. To increase the applicability of the T-S approach for uncertain nonlinear networked control systems, this study considers the asynchronous premise variables in the plant and the controller, and then introduces a robust stability analysis and control synthesis. The resulting optimal switching-fuzzy controller provides a minimum guaranteed cost on an H2 performance index. Simulation studies on three nonlinear benchmark problems demonstrate the effectiveness of the proposed method.
NASA Technical Reports Server (NTRS)
Levack, Daniel J. H.
2000-01-01
The objective of this contract was to provide definition of alternate propulsion systems for both earth-to-orbit (ETO) and in-space vehicles (upper stages and space transfer vehicles). For such propulsion systems, technical data to describe performance, weight, dimensions, etc. was provided along with programmatic information such as cost, schedule, needed facilities, etc. Advanced technology and advanced development needs were determined and provided. This volume separately presents the various program cost estimates that were generated under three tasks: the F- IA Restart Task, the J-2S Restart Task, and the SSME Upper Stage Use Task. The conclusions, technical results , and the program cost estimates are described in more detail in Volume I - Executive Summary and in individual Final Task Reports.
NASA Astrophysics Data System (ADS)
Holbourn, A. E.; Kuhnt, W.; Tada, R.; Murray, R. W.; Alvarez Zarikian, C. A.; Clemens, S. C.
2014-12-01
The SE Asian, Indian and Indonesian-Australian monsoonal subsystems are closely inter-linked, but show substantial differences in the spatial and temporal distribution of precipitation, mainly due to contrasting land-sea distribution and high latitude control. We explore changes in these subsystems in relation to high latitude climate variability on suborbital and orbital timescales, focusing on the last deglaciation and the long-term Miocene evolution. Our main proxies are δ18O and Mg/Ca based salinity and temperature reconstructions in combination with sedimentary and geochemical runoff signatures. Key issues are the synchroneity of monsoonal precipitation changes in relation to northern and southern hemisphere insolation and the response of individual subsystems to atmospheric CO2 and global ice volume variations. In contrast to northern hemisphere monsoonal records, the deglacial intensification of the Australian summer monsoon paralleled southern hemisphere climate evolution. We hypothesize that intensification of the summer heat low over the Australian continent through enhanced greenhouse forcing accentuated the southward pull of the Intertropical Convergence Zone (ITCZ). Additional forcing mechanisms including the variability of the Walker circulation and Indian Ocean Dipole, the heat and moisture transfer from the tropical Indian Ocean and deglacial sea-level changes remain highly debated. High-resolution Miocene records from the South China Sea (ODP Site 1146) indicate that the latitudinal displacement of the ITCZ also impacted the long-term development of the SE Asian summer monsoon. Antarctic ice growth episodes at 14.6, 14.2, 13.9, and 13.1 Ma coincided with surface warming and freshening, implying high sensitivity of tropical rain belts to the inter-hemispheric temperature gradient. However, comparable records of the long-term evolution of the Indian and Indonesian-Australian monsoonal subsystems that would allow testing of this hypothesis are still missing. High-resolution sedimentary archives recently recovered during IODP Expedition 346 (Asian Monsoon) and to be drilled during IODP Exp 353 (Indian Monsoon) will enable direct comparison of the three monsoonal subsystems and reconciliation of linkages between marine and land records.
Landsat-1 and Landsat-2 evaluation report, 23 January 1975 to 23 April 1975
NASA Technical Reports Server (NTRS)
1975-01-01
A description of the work accomplished with the Landsat-1 and Landsat-2 satellites during the period 23 Jan. - 23 Apr. 1975 was presented. The following information was given for each satellite: operational summary, orbital parameters, power subsystem, attitude control subsystem, command/clock subsystem, telemetry subsystem, orbit adjust subsystem, magnetic moment compensating assembly, unified S-band/premodulation processor, electrical interface subsystem, thermal subsystem, narrowband tape recorders, wideband telemetry subsystem, attitude measurement sensor, wideband video tape recorders, return beam vidicon, multispectral scanner subsystem, and data collection subsystem.
Applications Technology Satellite ATS-6 in orbit checkout report
NASA Technical Reports Server (NTRS)
Moore, W.; Prensky, W. (Editor)
1974-01-01
The activities of the ATS-6 spacecraft for the checkout period of approximately four weeks beginning May 30, 1974 are described, along with the results of a performance evaluation of its subsystems and components. The following specific items are discussed: (1) subsystem requirements/specifications and in-orbit performance summary; (2) flight chronology; (3) spacecraft description; (4) structural/deployment subsystems; (5) electrical power subsystem; (6) thermal control subsystem; (7) telemetry and command subsystems; (8) attitude control subsystem; (9) spacecraft propulsion subsystem; (10) communication subsystem; and (12) experiment subsystem.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sun, Y.; Tong, C.; Trainor-Guitten, W. J.
The risk of CO 2 leakage from a deep storage reservoir into a shallow aquifer through a fault is assessed and studied using physics-specific computer models. The hypothetical CO 2 geological sequestration system is composed of three subsystems: a deep storage reservoir, a fault in caprock, and a shallow aquifer, which are modeled respectively by considering sub-domain-specific physics. Supercritical CO 2 is injected into the reservoir subsystem with uncertain permeabilities of reservoir, caprock, and aquifer, uncertain fault location, and injection rate (as a decision variable). The simulated pressure and CO 2/brine saturation are connected to the fault-leakage model as amore » boundary condition. CO 2 and brine fluxes from the fault-leakage model at the fault outlet are then imposed in the aquifer model as a source term. Moreover, uncertainties are propagated from the deep reservoir model, to the fault-leakage model, and eventually to the geochemical model in the shallow aquifer, thus contributing to risk profiles. To quantify the uncertainties and assess leakage-relevant risk, we propose a global sampling-based method to allocate sub-dimensions of uncertain parameters to sub-models. The risk profiles are defined and related to CO 2 plume development for pH value and total dissolved solids (TDS) below the EPA's Maximum Contaminant Levels (MCL) for drinking water quality. A global sensitivity analysis is conducted to select the most sensitive parameters to the risk profiles. The resulting uncertainty of pH- and TDS-defined aquifer volume, which is impacted by CO 2 and brine leakage, mainly results from the uncertainty of fault permeability. Subsequently, high-resolution, reduced-order models of risk profiles are developed as functions of all the decision variables and uncertain parameters in all three subsystems.« less
The community deals with the child who has a handicap.
Bullard, I D; Dohnal, J T
1984-06-01
Exclusion messages, however subtle, are interwoven into the community of the child who is handicapped. The subsystems of family, religion, neighborhood, education, health care, and financial assistance agencies have good intentions but frequently communicate poorly with the child and the parents. What is meant as a help becomes a hindrance for the child who must adapt to a limitation while continuing to move toward self-esteem, self-sufficiency, and skills that will enhance productivity and employability. No one negative message will destroy a handicapped child: it is the "history of learned inferiority" that cripples the child who is handicapped. Only when able-bodied individuals within the subsystems recognize the cumulative effect of these messages will the community be responsive to the real needs of the child who has a handicap. Nurses, schooled in sensitivity for the person, should resolve to be in the vanguard in this movement, becoming ever more sensitive to the needs of the handicapped. Such a giant step will begin a fresh and long-needed approach toward understanding those needs central to the well-being of the child who resides in the community and is also handicapped.
NASA Technical Reports Server (NTRS)
Drummond, Mark; Hine, Butler; Genet, Russell; Genet, David; Talent, David; Boyd, Louis; Trueblood, Mark; Filippenko, Alexei V. (Editor)
1991-01-01
The objective of multi-use telescopes is to reduce the initial and operational costs of space telescopes to the point where a fair number of telescopes, a dozen or so, would be affordable. The basic approach is to develop a common telescope, control system, and power and communications subsystem that can be used with a wide variety of instrument payloads, i.e., imaging CCD cameras, photometers, spectrographs, etc. By having such a multi-use and multi-user telescope, a common practice for earth-based telescopes, development cost can be shared across many telescopes, and the telescopes can be produced in economical batches.
The 20 kW battery study program
NASA Technical Reports Server (NTRS)
1971-01-01
Six battery configurations were selected for detailed study and these are described. A computer program was modified for use in estimation of the weights, costs, and reliabilities of each of the configurations, as a function of several important independent variables, such as system voltage, battery voltage ratio (battery voltage/bus voltage), and the number of parallel units into which each of the components of the power subsystem was divided. The computer program was used to develop the relationship between the independent variables alone and in combination, and the dependent variables: weight, cost, and availability. Parametric data, including power loss curves, are given.
NASA Technical Reports Server (NTRS)
Rosenberg, L. S.; Revere, W. R.; Selcuk, M. K.
1981-01-01
Small solar thermal power systems (up to 10 MWe in size) were tested. The solar thermal power plant ranking study was performed to aid in experiment activity and support decisions for the selection of the most appropriate technological approach. The cost and performance were determined for insolation conditions by utilizing the Solar Energy Simulation computer code (SESII). This model optimizes the size of the collector field and energy storage subsystem for given engine generator and energy transport characteristics. The development of the simulation tool, its operation, and the results achieved from the analysis are discussed.
Design of a Low Cost Short Takeoff-vertical Landing Export Fighter/attack Aircraft
NASA Technical Reports Server (NTRS)
Belcher, Anne; Bodeker, Dan, III; Miu, Steve; Petro, Laura; Senf, Cary Taylor; Woeltjen, Donald
1990-01-01
The design of a supersonic short takeoff and vertical landing (STOVL) aircraft is presented that is suitable for export. An advanced four poster, low bypass turbofan engine is to be used for propulsion. Preliminary aerodynamic analysis is presented covering a determination of CD versus CL, CD versus Mach number, as well as best cruise Mach number and altitude. Component locations are presented and center of gravity determined. Cost minimization is achieved through the use of developed subsystems and standard fabrication techniques using nonexotic materials. Conclusions regarding the viability of the STOVL design are presented.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Easton, C. R.
The objectives of this program are to establish a heliostat design with the associated manufacturing, assembly, installation and maintenance approaches that will: (1) yield a significant reduction of capital and operating costs; (2) meet performance specifications for large collector subsystems; and (3) can be produced and deployed throughout the southwestern United States. In addition, cost plans and schedules to develop, fabricate, and operate the heliostat are to be developed. This volume presents the collector design, including trade study and test results, and the manufacturing, installation and checkout, and operations and maintenance concepts. Also, a discussion of specification verification and optimizationmore » is included. (WHK)« less
Development and Analysis of New Integrated Energy Systems for Sustainable Buildings
NASA Astrophysics Data System (ADS)
Khalid, Farrukh
Excessive consumption of fossil fuels in the residential sector and their associated negative environmental impacts bring a significant challenge to engineers within research and industrial communities throughout the world to develop more environmentally benign methods of meeting energy needs of residential sector in particular. This thesis addresses potential solutions for the issue of fossils fuel consumption in residential buildings. Three novel renewable energy based multigeneration systems are proposed for different types of residential buildings, and a comprehensive assessment of energetic and exergetic performances is given on the basis of total occupancy, energy load, and climate conditions. System 1 is a multigeneration system based on two renewable energy sources. It uses biomass and solar resources. The outputs of System 1 are electricity, space heating, cooling, and hot water. The energy and exergy efficiencies of System 1 are 91.0% and 34.9%, respectively. The results of the optimisation analysis show that the net present cost of System 1 is 2,700,496 and that the levelised cost of electricity is 0.117/kWh. System 2 is a multigeneration system, integrating three renewable energy based subsystems; wind turbine, concentrated solar collector, and Organic Rankine Cycle supplied by a ground source heat exchanger. The outputs of the System 2 are electricity, hot water, heating and cooling. The optimisation analysis shows that net present cost is 35,502 and levelised cost of electricity is 0.186/kWh. The energy and exergy efficiencies of System 2 are found to be 34.6% and 16.2%, respectively. System 3 is a multigeneration system, comprising two renewable energy subsystems-- geothermal and solar to supply power, cooling, heating, and hot water. The optimisation analysis shows that the net present cost of System 3 is 598,474, and levelised cost of electricity of 0.111/kWh. The energy and exergy efficiencies of System 3 are 20.2% and 19.2%, respectively, with outputs of electricity, hot water, cooling and space heating. A performance assessment for identical conditions indicates that System 3 offers the best performance, with the minimum net present cost of 26,001 and levelised cost of electricity of 0.136/kWh.
Evaluating the potential for secondary mass savings in vehicle lightweighting.
Alonso, Elisa; Lee, Theresa M; Bjelkengren, Catarina; Roth, Richard; Kirchain, Randolph E
2012-03-06
Secondary mass savings are mass reductions that may be achieved in supporting (load-bearing) vehicle parts when the gross vehicle mass (GVM) is reduced. Mass decompounding is the process by which it is possible to identify further reductions when secondary mass savings result in further reduction of GVM. Maximizing secondary mass savings (SMS) is a key tool for maximizing vehicle fuel economy. In today's industry, the most complex parts, which require significant design detail (and cost), are designed first and frozen while the rest of the development process progresses. This paper presents a tool for estimating SMS potential early in the design process and shows how use of the tool to set SMS targets early, before subsystems become locked in, maximizes mass savings. The potential for SMS in current passenger vehicles is estimated with an empirical model using engineering analysis of vehicle components to determine mass-dependency. Identified mass-dependent components are grouped into subsystems, and linear regression is performed on subsystem mass as a function of GVM. A Monte Carlo simulation is performed to determine the mean and 5th and 95th percentiles for the SMS potential per kilogram of primary mass saved. The model projects that the mean theoretical secondary mass savings potential is 0.95 kg for every 1 kg of primary mass saved, with the 5th percentile at 0.77 kg/kg when all components are available for redesign. The model was used to explore an alternative scenario where realistic manufacturing and design limitations were implemented. In this case study, four key subsystems (of 13 total) were locked-in and this reduced the SMS potential to a mean of 0.12 kg/kg with a 5th percentile of 0.1 kg/kg. Clearly, to maximize the impact of mass reduction, targets need to be established before subsystems become locked in.
Data archiving and serving system implementation in CLEP's GRAS Core System
NASA Astrophysics Data System (ADS)
Zuo, Wei; Zeng, Xingguo; Zhang, Zhoubin; Geng, Liang; Li, Chunlai
2017-04-01
The Ground Research & Applications System(GRAS) is one of the five systems of China's Lunar Exploration Project(CLEP), it is responsible for data acquisition, processing, management and application, and it is also the operation control center during satellite in-orbit and payload operation management. Chang'E-1, Chang'E-2 and Chang'E-3 have collected abundant lunar exploration data. The aim of this work is to present the implementation of data archiving and Serving in CLEP's GRAS Core System software. This first approach provides a client side API and server side software allowing the creation of a simplified version of CLEPDB data archiving software, and implements all required elements to complete data archiving flow from data acquisition until its persistent storage technology. The client side includes all necessary components that run on devices that acquire or produce data, distributing and streaming to configure remote archiving servers. The server side comprises an archiving service that stores into PDS files all received data. The archiving solution aims at storing data coming for the Data Acquisition Subsystem, the Operation Management Subsystem, the Data Preprocessing Subsystem and the Scientific Application & Research Subsystem. The serving solution aims at serving data for the various business systems, scientific researchers and public users. The data-driven and component clustering methods was adopted in this system, the former is used to solve real-time data archiving and data persistence services; the latter is used to keep the continuous supporting ability of archive and service to new data from Chang'E Mission. Meanwhile, it can save software development cost as well.
ISS Double-Gimbaled CMG Subsystem Simulation Using the Agile Development Method
NASA Technical Reports Server (NTRS)
Inampudi, Ravi
2016-01-01
This paper presents an evolutionary approach in simulating a cluster of 4 Control Moment Gyros (CMG) on the International Space Station (ISS) using a common sense approach (the agile development method) for concurrent mathematical modeling and simulation of the CMG subsystem. This simulation is part of Training systems for the 21st Century simulator which will provide training for crew members, instructors, and flight controllers. The basic idea of how the CMGs on the space station are used for its non-propulsive attitude control is briefly explained to set up the context for simulating a CMG subsystem. Next different reference frames and the detailed equations of motion (EOM) for multiple double-gimbal variable-speed control moment gyroscopes (DGVs) are presented. Fixing some of the terms in the EOM becomes the special case EOM for ISS's double-gimbaled fixed speed CMGs. CMG simulation development using the agile development method is presented in which customer's requirements and solutions evolve through iterative analysis, design, coding, unit testing and acceptance testing. At the end of the iteration a set of features implemented in that iteration are demonstrated to the flight controllers thus creating a short feedback loop and helping in creating adaptive development cycles. The unified modeling language (UML) tool is used in illustrating the user stories, class designs and sequence diagrams. This incremental development approach of mathematical modeling and simulating the CMG subsystem involved the development team and the customer early on, thus improving the quality of the working CMG system in each iteration and helping the team to accurately predict the cost, schedule and delivery of the software.
NASA Technical Reports Server (NTRS)
Ivancic, William D.; Shalkhauser, Mary JO
1991-01-01
Emphasis is on a destination directed packet switching architecture for a 30/20 GHz frequency division multiplex access/time division multiplex (FDMA/TDM) geostationary satellite communication network. Critical subsystems and problem areas are identified and addressed. Efforts have concentrated heavily on the space segment; however, the ground segment was considered concurrently to ensure cost efficiency and realistic operational constraints.
Preliminary candidate advanced avionics system for general aviation
NASA Technical Reports Server (NTRS)
Mccalla, T. M.; Grismore, F. L.; Greatline, S. E.; Birkhead, L. M.
1977-01-01
An integrated avionics system design was carried out to the level which indicates subsystem function, and the methods of overall system integration. Sufficient detail was included to allow identification of possible system component technologies, and to perform reliability, modularity, maintainability, cost, and risk analysis upon the system design. Retrofit to older aircraft, availability of this system to the single engine two place aircraft, was considered.
Circuit-switch architecture for a 30/20-GHz FDMA/TDM geostationary satellite communications network
NASA Technical Reports Server (NTRS)
Ivancic, William D.
1992-01-01
A circuit switching architecture is described for a 30/20 GHz frequency division, multiple access uplink/time division multiplexed downlink (FDMA/TDM) geostationary satellite communications network. Critical subsystems and problem areas are identified and addressed. Work was concentrated primarily on the space segment; however, the ground segment was considered concurrently to ensure cost efficiency and realistic operational constraints.
NASA Technical Reports Server (NTRS)
Ivancic, William D.; Shalkhauser, Mary JO
1992-01-01
A destination-directed packet switching architecture for a 30/20-GHz frequency division multiple access/time division multiplexed (FDMA/TDM) geostationary satellite communications network is discussed. Critical subsystems and problem areas are identified and addressed. Efforts have concentrated heavily on the space segment; however, the ground segment has been considered concurrently to ensure cost efficiency and realistic operational constraints.
A hybrid air conditioner driven by a hybrid solar collector
NASA Astrophysics Data System (ADS)
Al-Alili, Ali
The objective of this thesis is to search for an efficient way of utilizing solar energy in air conditioning applications. The current solar Air Conditioners (A/C)s suffer from low Coefficient of Performance (COP) and performance degradation in hot and humid climates. By investigating the possible ways of utilizing solar energy in air conditioning applications, the bottlenecks in these approaches were identified. That resulted in proposing a novel system whose subsystem synergy led to a COP higher than unity. The proposed system was found to maintain indoor comfort at a higher COP compared to the most common solar A/Cs, especially under very hot and humid climate conditions. The novelty of the proposed A/C is to use a concentrating photovoltaic/thermal collector, which outputs thermal and electrical energy simultaneously, to drive a hybrid A/C. The performance of the hybrid A/C, which consists of a desiccant wheel, an enthalpy wheel, and a vapor compression cycle (VCC), was investigated experimentally. This work also explored the use of a new type of desiccant material, which can be regenerated with a low temperature heat source. The experimental results showed that the hybrid A/C is more effective than the standalone VCC in maintaining the indoor conditions within the comfort zone. Using the experimental data, the COP of the hybrid A/C driven by a hybrid solar collector was found to be at least double that of the current solar A/Cs. The innovative integration of its subsystems allows each subsystem to do what it can do best. That leads to lower energy consumption which helps reduce the peak electrical loads on electric utilities and reduces the consumer operating cost since less energy is purchased during the on peak periods and less solar collector area is needed. In order for the proposed A/C to become a real alternative to conventional systems, its performance and total cost were optimized using the experimentally validated model. The results showed that for an electricity price of 0.12 $/kW-hr, the hybrid solar A/C's cumulative total cost will be less than that of a standard VCC after 17.5 years of operation.
NASA Astrophysics Data System (ADS)
Hassan, Rania A.
In the design of complex large-scale spacecraft systems that involve a large number of components and subsystems, many specialized state-of-the-art design tools are employed to optimize the performance of various subsystems. However, there is no structured system-level concept-architecting process. Currently, spacecraft design is heavily based on the heritage of the industry. Old spacecraft designs are modified to adapt to new mission requirements, and feasible solutions---rather than optimal ones---are often all that is achieved. During the conceptual phase of the design, the choices available to designers are predominantly discrete variables describing major subsystems' technology options and redundancy levels. The complexity of spacecraft configurations makes the number of the system design variables that need to be traded off in an optimization process prohibitive when manual techniques are used. Such a discrete problem is well suited for solution with a Genetic Algorithm, which is a global search technique that performs optimization-like tasks. This research presents a systems engineering framework that places design requirements at the core of the design activities and transforms the design paradigm for spacecraft systems to a top-down approach rather than the current bottom-up approach. To facilitate decision-making in the early phases of the design process, the population-based search nature of the Genetic Algorithm is exploited to provide computationally inexpensive---compared to the state-of-the-practice---tools for both multi-objective design optimization and design optimization under uncertainty. In terms of computational cost, those tools are nearly on the same order of magnitude as that of standard single-objective deterministic Genetic Algorithm. The use of a multi-objective design approach provides system designers with a clear tradeoff optimization surface that allows them to understand the effect of their decisions on all the design objectives under consideration simultaneously. Incorporating uncertainties avoids large safety margins and unnecessary high redundancy levels. The focus on low computational cost for the optimization tools stems from the objective that improving the design of complex systems should not be achieved at the expense of a costly design methodology.
NASA Astrophysics Data System (ADS)
Tohidnia, S.; Tohidi, G.
2018-02-01
The current paper develops three different ways to measure the multi-period global cost efficiency for homogeneous networks of processes when the prices of exogenous inputs are known at all time periods. A multi-period network data envelopment analysis model is presented to measure the minimum cost of the network system based on the global production possibility set. We show that there is a relationship between the multi-period global cost efficiency of network system and its subsystems, and also its processes. The proposed model is applied to compute the global cost Malmquist productivity index for measuring the productivity changes of network system and each of its process between two time periods. This index is circular. Furthermore, we show that the productivity changes of network system can be defined as a weighted average of the process productivity changes. Finally, a numerical example will be presented to illustrate the proposed approach.
Engineering and fabrication cost considerations for cryogenic wind tunnel models
NASA Technical Reports Server (NTRS)
Boykin, R. M., Jr.; Davenport, J. B., Jr.
1983-01-01
Design and fabrication cost drivers for cryogenic transonic wind tunnel models are defined. The major cost factors for wind tunnel models are model complexity, tolerances, surface finishes, materials, material validation, and model inspection. The cryogenic temperatures require the use of materials with relatively high fracture toughness but at the same time high strength. Some of these materials are very difficult to machine, requiring extensive machine hours which can add significantly to the manufacturing costs. Some additional engineering costs are incurred to certify the materials through mechanical tests and nondestructive evaluation techniques, which are not normally required with conventional models. When instrumentation such as accelerometers and electronically scanned pressure modules is required, temperature control of these devices needs to be incorporated into the design, which requires added effort. Additional thermal analyses and subsystem tests may be necessary, which also adds to the design costs. The largest driver to the design costs is potentially the additional static and dynamic analyses required to insure structural integrity of the model and support system.
Incorporating Oracle on-line space management with long-term archival technology
NASA Technical Reports Server (NTRS)
Moran, Steven M.; Zak, Victor J.
1996-01-01
The storage requirements of today's organizations are exploding. As computers continue to escalate in processing power, applications grow in complexity and data files grow in size and in number. As a result, organizations are forced to procure more and more megabytes of storage space. This paper focuses on how to expand the storage capacity of a Very Large Database (VLDB) cost-effectively within a Oracle7 data warehouse system by integrating long term archival storage sub-systems with traditional magnetic media. The Oracle architecture described in this paper was based on an actual proof of concept for a customer looking to store archived data on optical disks yet still have access to this data without user intervention. The customer had a requirement to maintain 10 years worth of data on-line. Data less than a year old still had the potential to be updated thus will reside on conventional magnetic disks. Data older than a year will be considered archived and will be placed on optical disks. The ability to archive data to optical disk and still have access to that data provides the system a means to retain large amounts of data that is readily accessible yet significantly reduces the cost of total system storage. Therefore, the cost benefits of archival storage devices can be incorporated into the Oracle storage medium and I/O subsystem without loosing any of the functionality of transaction processing, yet at the same time providing an organization access to all their data.
Thermal storage requirements for parabolic dish solar power plants
NASA Technical Reports Server (NTRS)
Wen, L.; Steele, H.
1980-01-01
The cost effectiveness of a high temperature thermal storage system is investigated for a representative parabolic dish solar power plant. The plant supplies electrical power in accordance with a specific, seasonally varying demand profile. The solar power received by the plant is supplemented by power from fuel combustion. The cost of electricity generated by the solar power plant is calculated, using the cost of mass-producible subsystems (specifically, parabolic dishes, receivers, and power conversion units) now being designed for this type of solar plant. The trade-off between fuel and thermal storage is derived in terms of storage effectiveness, the cost of storage devices, and the cost of fuel. Thermal storage requirements, such as storage capacity, storage effectiveness, and storage cost are established based on the cost of fuel and the overall objective of minimizing the cost of the electricity produced by the system. As the cost of fuel increases at a rate faster than general inflation, thermal storage systems in the $40 to $70/kWthr range could become cost effective in the near future.
A local network integrated into a balloon-borne apparatus
NASA Astrophysics Data System (ADS)
Imori, Masatosi; Ueda, Ikuo; Shimamura, Kotaro; Maeno, Tadashi; Murata, Takahiro; Sasaki, Makoto; Matsunaga, Hiroyuki; Matsumoto, Hiroshi; Shikaze, Yoshiaki; Anraku, Kazuaki; Matsui, Nagataka; Yamagami, Takamasa
A local network is incorporated into an apparatus for a balloon-borne experiment. A balloon-borne system implemented in the apparatus is composed of subsystems interconnected through a local network, which introduces modular architecture into the system. The network decomposes the balloon-borne system into subsystems, which are similarly structured from the point of view that the systems is kept under the control of a ground station. The subsystem is functionally self-contained and electrically independent. A computer is integrated into a subsystem, keeping the subsystem under the control. An independent group of batteries, being dedicated to a subsystem, supplies the whole electricity of the subsystem. The subsystem could be turned on and off independently of the other subsystems. So communication among the subsystems needs to be based on such a protocol that could guarantee the independence of the individual subsystems. An Omninet protocol is employed to network the subsystems. A ground station sends commands to the balloon-borne system. The command is received and executed at the system, then results of the execution are returned to the ground station. Various commands are available so that the system borne on a balloon could be controlled and monitored remotely from the ground station. A subsystem responds to a specific group of commands. A command is received by a transceiver subsystem and then transferred through the network to the subsystem to which the command is addressed. Then the subsystem executes the command and returns results to the transceiver subsystem, where the results are telemetered to the ground station. The network enhances independence of the individual subsystems, which enables programs of the individual subsystems to be coded independently. Independence facilitates development and debugging of programs, improving the quality of the system borne on a balloon.
Integrated system for investigating sub-surface features of a rock formation
Vu, Cung Khac; Skelt, Christopher; Nihei, Kurt; Johnson, Paul A.; Guyer, Robert; Ten Cate, James A.; Le Bas, Pierre -Yves; Larmat, Carene S.
2015-08-18
A system for investigating non-linear properties of a rock formation around a borehole is provided. The system includes a first sub-system configured to perform data acquisition, control and recording of data; a second subsystem in communication with the first sub-system and configured to perform non-linearity and velocity preliminary imaging; a third subsystem in communication with the first subsystem and configured to emit controlled acoustic broadcasts and receive acoustic energy; a fourth subsystem in communication with the first subsystem and the third subsystem and configured to generate a source signal directed towards the rock formation; and a fifth subsystem in communication with the third subsystem and the fourth subsystem and configured to perform detection of signals representative of the non-linear properties of the rock formation.
NASA Technical Reports Server (NTRS)
Goldberg, Ben E.; Wiley, Dan R.
1991-01-01
An overview is presented of hybrid rocket propulsion systems whereby combining solids and liquids for launch vehicles could produce a safe, reliable, and low-cost product. The primary subsystems of a hybrid system consist of the oxidizer tank and feed system, an injector system, a solid fuel grain enclosed in a pressure vessel case, a mixing chamber, and a nozzle. The hybrid rocket has an inert grain, which reduces costs of development, transportation, manufacturing, and launch by avoiding many safety measures that must be taken when operating with solids. Other than their use in launch vehicles, hybrids are excellent for simulating the exhaust of solid rocket motors for material development.
A cellular glass substrate solar concentrator
NASA Technical Reports Server (NTRS)
Bedard, R.; Bell, D.
1980-01-01
The design of a second generation point focusing solar concentration is discussed. The design is based on reflective gores fabricated of thin glass mirror bonded continuously to a contoured substrate of cellular glass. The concentrator aperture and structural stiffness was optimized for minimum concentrator cost given the performance requirement of delivering 56 kWth to a 22 cm diameter receiver aperture with a direct normal insolation of 845 watts sq m and an operating wind of 50 kmph. The reflective panel, support structure, drives, foundation and instrumentation and control subsystem designs, optimized for minimum cost, are summarized. The use of cellular glass as a reflective panel substrate material is shown to offer significant weight and cost advantages compared to existing technology materials.
Parallel integrated frame synchronizer chip
NASA Technical Reports Server (NTRS)
Solomon, Jeffrey Michael (Inventor); Ghuman, Parminder Singh (Inventor); Bennett, Toby Dennis (Inventor)
2000-01-01
A parallel integrated frame synchronizer which implements a sequential pipeline process wherein serial data in the form of telemetry data or weather satellite data enters the synchronizer by means of a front-end subsystem and passes to a parallel correlator subsystem or a weather satellite data processing subsystem. When in a CCSDS mode, data from the parallel correlator subsystem passes through a window subsystem, then to a data alignment subsystem and then to a bit transition density (BTD)/cyclical redundancy check (CRC) decoding subsystem. Data from the BTD/CRC decoding subsystem or data from the weather satellite data processing subsystem is then fed to an output subsystem where it is output from a data output port.
An Analytical Calibration Approach for the Polarimetric Airborne C Band Radiometer
NASA Technical Reports Server (NTRS)
Pham, Hanh; Kim, Edward J.
2004-01-01
Passive microwave remote sensing is sensitive to the quantity and distribution of water in soil and vegetation. During summer 2000, the Microwave Geophysics Group a t the University of Michigan conducted the seventh Radiobrighness Energy Balance Experiment (REBEX-7) over a corn canopy in Michigan. Long time series of brightness temperatures, soil moisture and micrometeorology on the plot were taken. This paper addresses the calibration of the NASA GSFC polarimetric airborne C band microwave radiometer (ACMR) that participated in REBEX-7. These passive polarimeters are typically calibrated using an end-to-end approach based upon a standard artificial target or a well-known geophysical target. Analyzing the major internal functional subsystems offers a different perspective. The primary goal of this approach is to provide a transfer function that not only describes the system in its entire5 but also accounts for the contributions of each subsystem toward the final modified Stokes parameters. This approach does not assume that the radiometric system is linear as it does not take polarization isolation for granted, and it also serves as a realistic instrument simulator, a useful tool for future designs. The ACMR architecture can be partitioned into functional subsystems. The characteristics of each subsystem was extensively measured and the estimated parameters were imported into the overall dosed form system model. Inversion of the model yields a calibration for the modeled Stokes parameters with uncertainties of 0.2 K for the V and H polarizations and 2.4 K for the 3rd and 4th parameters. Application to the full Stokes parameters over a senescent cornfield is presented.
Danon-Schaffer, Monica N; Mahecha-Botero, Andrés; Grace, John R; Ikonomou, Michael
2013-09-01
Previous research on brominated flame retardants (BFRs), including polybrominated diphenyl ethers (PBDEs) has largely focussed on their concentrations in the environment and their adverse effects on human health. This paper explores their transfer from waste streams to water and soil. A comprehensive mass balance model is developed to track polybrominated diphenyl ethers (PBDEs), originating from e-waste and non-e-waste solids leaching from a landfill. Stepwise debromination is assumed to occur in three sub-systems (e-waste, aqueous leachate phase, and non-e-waste solids). Analysis of landfill samples and laboratory results from a solid-liquid contacting chamber are used to estimate model parameters to simulate an urban landfill system, for past and future scenarios. Sensitivity tests to key model parameters were conducted. Lower BDEs require more time to disappear than high-molecular weight PBDEs, since debromination takes place in a stepwise manner, according to the simplified reaction scheme. Interphase mass transfer causes the decay pattern to be similar in all three sub-systems. The aqueous phase is predicted to be the first sub-system to eliminate PBDEs if their input to the landfill were to be stopped. The non-e-waste solids would be next, followed by the e-waste sub-system. The model shows that mass transfer is not rate-limiting, but the evolution over time depends on the kinetic degradation parameters. Experimental scatter makes model testing difficult. Nevertheless, the model provides qualitative understanding of the influence of key variables. Copyright © 2013 Elsevier B.V. All rights reserved.
NASA Technical Reports Server (NTRS)
Choi, Josh; Sanders, Antonio
2012-01-01
Soil Moisture Active Passive (SMAP) is an Earth-orbiting, remote-sensing NASA mission slated for launch in 2014. The ground data system (GDS) being developed for SMAP is composed of many heterogeneous subsystems, ranging from those that support planning and sequencing to those used for real-time operations, and even further to those that enable science data exchange. A full end-to-end automation of the GDS may result in cost savings during mission operations, but it would require a significant upfront investment to develop such a comprehensive automation. As demonstrated by the Jason-1 and Wide-field Infrared Survey Explorer (WISE) missions, a measure of "lights-out" automation for routine, orbital pass, ground operations can still reduce mission costs through smaller staffing of operators and limiting their working hours. The challenge, then, for the SMAP GDS engineering team, is to formulate an automated operations strategy--and corresponding system architecture -- to minimize operator intervention during routine operations, while balancing the development costs associated with the scope and complexity of automation. This paper discusses the automated operations approach being developed for the SMAP GDS. The focus is on automating the activities involved in routine passes, which limits the scope to real-time operations. A key subsystem of the SMAP GDS -- NASA's AMMOS Mission Data Processing and Control System (AMPCS) -- provides a set of capabilities that enable such automation. Also discussed are the lights-out pass automations of the Jason-1 and WISE missions and how they informed the automation strategy for SMAP. The paper aims to provide insights into what is necessary in automating the GDS operations for Earth satellite missions.
NASA Technical Reports Server (NTRS)
Choi, Joshua S.; Sanders, Antonio L.
2012-01-01
Soil Moisture Active Passive (SMAP) is an Earth-orbiting, remote-sensing NASA mission slated for launch in 2014.[double dagger] The ground data system (GDS) being developed for SMAP is composed of many heterogeneous subsystems, ranging from those that support planning and sequencing to those used for real-time operations, and even further to those that enable science data exchange. A full end-to-end automation of the GDS may result in cost savings during mission operations, but it would require a significant upfront investment to develop such comprehensive automation. As demonstrated by the Jason-1 and Wide-field Infrared Survey Explorer (WISE) missions, a measure of "lights-out" automation for routine, orbital pass ground operations can still reduce mission cost through smaller staffing of operators and limited work hours. The challenge, then, for the SMAP GDS engineering team is to formulate an automated operations strategy--and corresponding system architecture--to minimize operator intervention during operations, while balancing the development cost associated with the scope and complexity of automation. This paper discusses the automated operations approach being developed for the SMAP GDS. The focus is on automating the activities involved in routine passes, which limits the scope to real-time operations. A key subsystem of the SMAP GDS--NASA's AMMOS Mission Data Processing and Control System (AMPCS)--provides a set of capabilities that enable such automation. Also discussed are the lights-out pass automations of the Jason-1 and WISE missions and how they informed the automation strategy for SMAP. The paper aims to provide insights into what is necessary in automating the GDS operations for Earth satellite missions.
A low cost, high performance remotely controlled backhoe/excavator
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rizzo, J.
1995-12-31
This paper addresses a state of the art, low cost, remotely controlled backhoe/excavator system for remediation use at hazardous waste sites. The all weather, all terrain, Remote Dig-It is based on a simple, proven construction platform and incorporates state of the art sensors, control, telemetry and other subsystems derived from advanced underwater remotely operated vehicle systems. The system can be towed to a site without the use of a trailer, manually operated by an on board operator or operated via a fiber optic or optional RF communications link by a remotely positioned operator. A proportional control system is piggy backedmore » onto the standard manual control system. The control system improves manual operation, allows rapid manual/remote mode selection and provides fine manual or remote control of all functions. The system incorporates up to 4 separate video links, acoustic obstacle proximity sensors, and stereo audio pickups and an optional differential GPS navigation. Video system options include electronic panning and tilting within a distortion-corrected wide angle field of view. The backhoe/excavator subsystem has a quick disconnect interface feature which allows its use as a manipulator with a wide variety of end effectors and tools. The Remote Dig-It was developed to respond to the need for a low-cost, effective remediation system for use at sites containing hazardous materials. The prototype system was independently evaluated for this purpose by the Army at the Jefferson Proving Ground where it surpassed all performance goals. At the time of this writing, the Remote Dig-It system is currently the only backhoe/excavator which met the Army`s goals for remediation systems for use at hazardous waste sites and it costs a fraction of any known competing offerings.« less
Cost, capability, and risk for planetary operations
NASA Technical Reports Server (NTRS)
Mclaughlin, William I.; Deutsch, Marie J.; Miller, Lanny J.; Wolff, Donna M.; Zawacki, Steven J.
1992-01-01
The three key factors for flight projects - cost, capability, and risk - are examined with respect to their interplay, the uplink process, cost drivers, and risk factors. Scientific objectives are translated into a computer program during the uplink process, and examples are given relating to the Voyager Interstellar Mission, Galileo, and the Comet Rendezvous Asteroid Flyby. The development of a multimission sequence system based on these uplinks is described with reference to specific subsystems such as the pointer and the sequence generator. Operational cost drivers include mission, flight-system, and ground-system complexity, uplink traffic, and work force. Operational risks are listed in terms of the mission operations, the environment, and the mission facilities. The uplink process can be analyzed in terms of software development, and spacecraft operability is shown to be an important factor from the initial stages of spacecraft development.
Subsystem Analysis/Optimization for the X-34 Main Propulsion System
NASA Technical Reports Server (NTRS)
McDonald, J. P.; Hedayat, A.; Brown, T. M.; Knight, K. C.; Champion, R. H., Jr.
1998-01-01
The Orbital Sciences Corporation X-34 vehicle demonstrates technologies and operations key to future reusable launch vehicles. The general flight performance goal of this unmanned rocket plane is Mach 8 flight at an altitude of 250,000 feet. The Main Propulsion System (MPS) supplies liquid propellants to the main engine, which provides the primary thrust for attaining mission goals. Major MPS design and operational goals are aircraft-like ground operations, quick turnaround between missions, and low initial/operational costs. Analyses related to optimal MPS subsystem design are reviewed in this paper. A pressurization system trade weighs maintenance/reliability concerns against those for safety in a comparison of designs using pressure regulators versus orifices to control pressurant flow. A propellant dump/feed system analysis weighs the issues of maximum allowable vehicle landing weight, trajectory, and MPS complexity to arrive at a final configuration for propellant dump/feed systems.
Development and in-flight performance of the Mariner 9 spacecraft propulsion system
NASA Technical Reports Server (NTRS)
Evans, D. D.; Cannova, R. D.; Cork, M. J.
1973-01-01
On November 14, 1971, Mariner 9 was decelerated into orbit about Mars by a 1334 N (300 lbf) liquid bipropellant propulsion system. This paper describes and summarizes the development and in-flight performance of this pressure-fed, nitrogen tetroxide/monomethyl hydrazine bipropellant system. The design of all Mariner propulsion subsystems has been predicted upon the premise that simplicity of approach, coupled with thorough qualification and margin-limits testing, is the key to cost-effective reliability. The qualification test program and analytical modeling are also discussed. Since the propulsion subsystem is modular in nature, it was completely checked, serviced, and tested independent of the spacecraft. Proper prediction of in-flight performance required the development of three significant modeling tools to predict and account for nitrogen saturation of the propellant during the six-month coast period and to predict and statistically analyze in-flight data.
Development of a Computer Writing System Based on EOG
López, Alberto; Ferrero, Francisco; Yangüela, David; Álvarez, Constantina; Postolache, Octavian
2017-01-01
The development of a novel computer writing system based on eye movements is introduced herein. A system of these characteristics requires the consideration of three subsystems: (1) A hardware device for the acquisition and transmission of the signals generated by eye movement to the computer; (2) A software application that allows, among other functions, data processing in order to minimize noise and classify signals; and (3) A graphical interface that allows the user to write text easily on the computer screen using eye movements only. This work analyzes these three subsystems and proposes innovative and low cost solutions for each one of them. This computer writing system was tested with 20 users and its efficiency was compared to a traditional virtual keyboard. The results have shown an important reduction in the time spent on writing, which can be very useful, especially for people with severe motor disorders. PMID:28672863
NASA Technical Reports Server (NTRS)
Neil, A. L.
1973-01-01
The Pioneer Venus mission study was conducted for a probe spacecraft and an orbiter spacecraft to be launched by either a Thor/Delta or an Atlas/Centaur launch vehicle. Both spacecraft are spin stabilized. The spin speed is controlled by ground commands to as low as 5 rpm for science instrument scanning on the orbiter and as high as 71 rpm for small probes released from the probe bus. A major objective in the design of the attitude control and mechanism subsystem (ACMS) was to provide, in the interest of costs, maximum commonality of the elements between the probe bus and orbiter spacecraft configurations. This design study was made considering the use of either launch vehicle. The basic functional requirements of the ACMS are derived from spin axis pointing and spin speed control requirements implicit in the acquisition, cruise, encounter and orbital phases of the Pioneer Venus missions.
Monolithic Microwave Integrated Circuit (MMIC) technology for space communications applications
NASA Technical Reports Server (NTRS)
Connolly, Denis J.; Bhasin, Kul B.; Romanofsky, Robert R.
1987-01-01
Future communications satellites are likely to use gallium arsenide (GaAs) monolithic microwave integrated-circuit (MMIC) technology in most, if not all, communications payload subsystems. Multiple-scanning-beam antenna systems are expected to use GaAs MMIC's to increase functional capability, to reduce volume, weight, and cost, and to greatly improve system reliability. RF and IF matrix switch technology based on GaAs MMIC's is also being developed for these reasons. MMIC technology, including gigabit-rate GaAs digital integrated circuits, offers substantial advantages in power consumption and weight over silicon technologies for high-throughput, on-board baseband processor systems. For the more distant future pseudomorphic indium gallium arsenide (InGaAs) and other advanced III-V materials offer the possibility of MMIC subsystems well up into the millimeter wavelength region. All of these technology elements are in NASA's MMIC program. Their status is reviewed.
Monolithic Microwave Integrated Circuit (MMIC) technology for space communications applications
NASA Technical Reports Server (NTRS)
Connolly, Denis J.; Bhasin, Kul B.; Romanofsky, Robert R.
1987-01-01
Future communications satellites are likely to use gallium arsenide (GaAs) monolithic microwave integrated-circuit (MMIC) technology in most, if not all, communications payload subsystems. Multiple-scanning-beam antenna systems are expected to use GaAs MMICs to increase functional capability, to reduce volume, weight, and cost, and to greatly improve system reliability. RF and IF matrix switch technology based on GaAs MMICs is also being developed for these reasons. MMIC technology, including gigabit-rate GaAs digital integrated circuits, offers substantial advantages in power consumption and weight over silicon technologies for high-throughput, on-board baseband processor systems. For the more distant future pseudomorphic indium gallium arsenide (InGaAs) and other advanced III-V materials offer the possibility of MMIC subsystems well up into the millimeter wavelength region. All of these technology elements are in NASA's MMIC program. Their status is reviewed.
Proposed 10 MWe OTEC pilot plant for the Commonwealth of the Northern Mariana Islands
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dunbar, L.E.; Chan, G.L.
1981-01-01
A preliminary conceptual design of a 10 MWe OTEC pilot plant has been proposed for the island of Saipan in the Commonwealth of the Northern Mariana Islands. This unique small OTEC plant is intended as a prototype for commercial plants in the small Pacific Island territories and nations. The system concept minimizes local construction to accommodate a lack of local skilled labor and facilities. The baseline design is a concrete barge-mounted plant built in Portland, Oregon, towed to Saipan, and permanently anchored in near-shore shallow water. Details of key subsystem design features are provided including a bottom-mounted cold water pipe,more » modular power subsystem, and wave shield for storm protection. The results of economic analyses are presented to illustrate the cost competitiveness of electricity from the OTEC plant compared to the current oil-fired diesel units in Saipan.« less
Proposed 10 MWe OTEC pilot plant for the Commonwealth of the Northern Mariana Islands
NASA Astrophysics Data System (ADS)
Dunbar, L. E.; Chan, G. L.
1981-12-01
A preliminary conceptual design of a 10 MWe OTEC pilot plant has been proposed for the island of Saipan in the Commonwealth of the Northern Mariana Islands. This unique small OTEC plant is intended as a prototype for commercial plants in the small Pacific Island territories and nations. The system concept minimizes local construction to accommodate a lack of local skilled labor and facilities. The baseline design is a concrete barge-mounted plant built in Portland, Oregon, towed to Saipan, and permanently anchored in near-shore shallow water. Details of key subsystem design features are provided including a bottom-mounted cold water pipe, modular power subsystem, and wave shield for storm protection. The results of economic analyses are presented to illustrate the cost competitiveness of electricity from the OTEC plant compared to the current oil-fired diesel units in Saipan.
Development of a Computer Writing System Based on EOG.
López, Alberto; Ferrero, Francisco; Yangüela, David; Álvarez, Constantina; Postolache, Octavian
2017-06-26
The development of a novel computer writing system based on eye movements is introduced herein. A system of these characteristics requires the consideration of three subsystems: (1) A hardware device for the acquisition and transmission of the signals generated by eye movement to the computer; (2) A software application that allows, among other functions, data processing in order to minimize noise and classify signals; and (3) A graphical interface that allows the user to write text easily on the computer screen using eye movements only. This work analyzes these three subsystems and proposes innovative and low cost solutions for each one of them. This computer writing system was tested with 20 users and its efficiency was compared to a traditional virtual keyboard. The results have shown an important reduction in the time spent on writing, which can be very useful, especially for people with severe motor disorders.
Practical design considerations for photovoltaic power station
NASA Astrophysics Data System (ADS)
Swanson, T. D.
Aspects of photovoltaic (PV) technology are discussed along with generic PV design considerations, taking into account the resource sunlight, PV modules and their reliability, questions of PV system design, the support structure subsystem, and a power conditioning unit subsystem. A description is presented of two recent projects which demonstrate the translation of an idea into actual working PV systems. A privately financed project in Denton, Maryland, went on line in early December, 1982, and began providing power to the local utility grid. It represents the first intermediate size, grid-connected, privately financed power station in the U.S. Based on firm quotes, the actual cost of this system is about $13/W peak. The other project, called the PV Breeder, is an energy independent facility which utilizes solar power to make new solar cells. It is also the first large industrial structure completely powered by the sun.
NASA Technical Reports Server (NTRS)
Fey, M. G.
1981-01-01
The experimental verification system for the production of silicon via the arc heater-sodium reduction of SiCl4 was designed, fabricated, installed, and operated. Each of the attendant subsystems was checked out and operated to insure performance requirements. These subsystems included: the arc heaters/reactor, cooling water system, gas system, power system, Control & Instrumentation system, Na injection system, SiCl4 injection system, effluent disposal system and gas burnoff system. Prior to introducing the reactants (Na and SiCl4) to the arc heater/reactor, a series of gas only-power tests was conducted to establish the operating parameters of the three arc heaters of the system. Following the successful completion of the gas only-power tests and the readiness tests of the sodium and SiCl4 injection systems, a shakedown test of the complete experimental verification system was conducted.
NASA Technical Reports Server (NTRS)
1974-01-01
The specifications for the Earth Observatory Satellite (EOS) general purpose aircraft segment are presented. The satellite is designed to provide attitude stabilization, electrical power, and a communications data handling subsystem which can support various mission peculiar subsystems. The various specifications considered include the following: (1) structures subsystem, (2) thermal control subsystem, (3) communications and data handling subsystem module, (4) attitude control subsystem module, (5) power subsystem module, and (6) electrical integration subsystem.
Optical analysis of the star-tracker telescope for Gravity Probe
NASA Technical Reports Server (NTRS)
Zissa, D. E.
1984-01-01
A ray tracing modeling of the star tracker telescope for Gravity Probe was used to predict the character of the output signal and its sensitivity to fabrication errors. In particular, the impact of the optical subsystem on the requirement of 1 milliarc second signal linearity over a + or - 50 milliarc second range was examined. Photomultiplier and solid state detector options were considered. Recommendations are made.
Design and fabrication of a CCD camera for use with relay optics in solar X-ray astronomy
NASA Technical Reports Server (NTRS)
1984-01-01
Configured as a subsystem of a sounding rocket experiment, a camera system was designed to record and transmit an X-ray image focused on a charge coupled device. The camera consists of a X-ray sensitive detector and the electronics for processing and transmitting image data. The design and operation of the camera are described. Schematics are included.
Shock Wave / Boundary Layer Interaction Experiment on Control Surface
2007-06-01
attachment points to the cold structure of the capsule (see Figure 16, left). Vibrational and acoustical loads are relevant for electronic components. Noise...thermal detector subsystems. Table 1: Summary of infrared technologies considered. Thermal Detectors Quantum Detectors Bolometer Pyrometer InGaAs...holes but a decrease in sensitivity at lower temperature results. Pyrometers are suitable for high temperature measurement, but they respond only to
NASA Astrophysics Data System (ADS)
Addiss, R. R., Jr.; Lawson, P. A.
1980-06-01
The design and performance of a photovoltaic power system is discussed. The 194 kW system consists of the photovoltaic array, the inverter/control subsystem, the building and utility interface, and the monitoring subsystem. The photovoltaic array consists of 56 separate subarrays of 112 photovoltaic modules each, deployed in rows on the southerly facing slope north of the school building. The wiring scheme permits individual modules to be disconnected without a radical change in subarray output current. Power is transmitted at 4160 V from the inverters and a step up transformer to the main 4160 V utility feed line in the school. Separate metering measures power bought and sold. At the optimum tilt angle of 40 deg, the array provides 232 MWH of AC energy annually, or 17 percent of the school load. The immediate impact is an $8000 saving in the annual utility bill. Levelized busbar energy costs are reduced from $2/kWH to $1/kWH when site specific parameters are used in the analysis instead of the JPL specified nominal values. A fault detection and isolation scheme which can find a single modulus failure is incorporated into the monitoring subsystem.
NASA Technical Reports Server (NTRS)
Maynard, O. E.; Brown, W. C.; Edwards, A.; Haley, J. T.; Meltz, G.; Howell, J. M.; Nathan, A.
1975-01-01
Introduction, organization, analyses, conclusions, and recommendations for each of the spaceborne subsystems are presented. Environmental effects - propagation analyses are presented with appendices covering radio wave diffraction by random ionospheric irregularities, self-focusing plasma instabilities and ohmic heating of the D-region. Analyses of dc to rf conversion subsystems and system considerations for both the amplitron and the klystron are included with appendices for the klystron covering cavity circuit calculations, output power of the solenoid-focused klystron, thermal control system, and confined flow focusing of a relativistic beam. The photovoltaic power source characteristics are discussed as they apply to interfacing with the power distribution flow paths, magnetic field interaction, dc to rf converter protection, power distribution including estimates for the power budget, weights, and costs. Analyses for the transmitting antenna consider the aperture illumination and size, with associated efficiencies and ground power distributions. Analyses of subarray types and dimensions, attitude error, flatness, phase error, subarray layout, frequency tolerance, attenuation, waveguide dimensional tolerances, mechanical including thermal considerations are included. Implications associated with transportation, assembly and packaging, attitude control and alignment are discussed. The phase front control subsystem, including both ground based pilot signal driven adaptive and ground command approaches with their associated phase errors, are analyzed.
NASA Technical Reports Server (NTRS)
Yeh, Hue-Hsia; Brown, Cheryl; Jeng, Frank
2012-01-01
Advanced Life Support Sizing Analysis Tool (ALSSAT) at the time of this reporting has been updated to version 6.0. A previous version was described in Tool for Sizing Analysis of the Advanced Life Support System (MSC- 23506), NASA Tech Briefs, Vol. 29, No. 12 (December 2005), page 43. To recapitulate: ALSSAT is a computer program for sizing and analyzing designs of environmental-control and life-support systems for spacecraft and surface habitats to be involved in exploration of Mars and the Moon. Of particular interest for analysis by ALSSAT are conceptual designs of advanced life-support (ALS) subsystems that utilize physicochemical and biological processes to recycle air and water and process human wastes to reduce the need of resource resupply. ALSSAT is a means of investigating combinations of such subsystems technologies featuring various alternative conceptual designs and thereby assisting in determining which combination is most cost-effective. ALSSAT version 6.0 has been improved over previous versions in several respects, including the following additions: an interface for reading sizing data from an ALS database, computational models of a redundant regenerative CO2 and Moisture Removal Amine Swing Beds (CAMRAS) for CO2 removal, upgrade of the Temperature & Humidity Control's Common Cabin Air Assembly to a detailed sizing model, and upgrade of the Food-management subsystem.
Avionics of the Cyclone Global Navigation Satellite System (CYGNSS) microsat constellation
NASA Astrophysics Data System (ADS)
Dickinson, John R.; Alvarez, Jennifer L.; Rose, Randall J.; Ruf, Christopher S.; Walls, Buddy J.
The Cyclone Global Navigation Satellite System (CYGNSS), which was recently selected as the Earth Venture-2 investigation by NASA's Earth Science System Pathfinder (ESSP) Program, measures the ocean surface wind field with unprecedented temporal resolution and spatial coverage, under all precipitating conditions, and over the full dynamic range of wind speeds experienced in a tropical cyclone (TC). The CYGNSS flight segment consists of 8 microsatellite-class observatories, which represent SwRI's first spacecraft bus design, installed on a Deployment Module for launch. They are identical in design but provide their own individual contribution to the CYGNSS science data set. Subsystems include the Attitude Determination and Control System (ADCS), the Communication and Data Subsystem (CDS), the Electrical Power Supply (EPS), and the Structure, Mechanisms, and Thermal Subsystem (SMT). This paper will present an overview of the mission and the avionics, including the ADCS, CDS, and EPS, in detail. Specifically, we will detail how off-the-shelf components can be utilized to do ADCS and will highlight how SwRI's existing avionics solutions will be adapted to meet the requirements and cost constraints of microsat applications. Avionics electronics provided by SwRI include a command and data handling computer, a transceiver radio, a low voltage power supply (LVPS), and a peak power tracker (PPT).
Does recyclable separation reduce the cost of municipal waste management in Japan?
Chifari, Rosaria; Lo Piano, Samuele; Matsumoto, Shigeru; Tasaki, Tomohiro
2017-02-01
Municipal solid waste (MSW) management is a system involving multiple sub-systems that typically require demanding inputs, materials and resources to properly process generated waste throughput. For this reason, MSW management is generally one of the most expensive services provided by municipalities. In this paper, we analyze the Japanese MSW management system and estimate the cost elasticity with respect to the waste volumes at three treatment stages: collection, processing, and disposal. Although we observe economies of scale at all three stages, the collection cost is less elastic than the disposal cost. We also examine whether source separation at home affects the cost of MSW management. The empirical results show that the separate collection of the recyclable fraction leads to reduced processing costs at intermediate treatment facilities, but does not change the overall waste management cost. Our analysis also reveals that the cost of waste management systems decreases when the service is provided by private companies through a public tender. The cost decreases even more when the service is performed under the coordination of adjacent municipalities. Copyright © 2017 Elsevier Ltd. All rights reserved.
NASA Technical Reports Server (NTRS)
Huang, Zhao-Feng; Fint, Jeffry A.; Kuck, Frederick M.
2005-01-01
This paper is to address the in-flight reliability of a liquid propulsion engine system for a launch vehicle. We first establish a comprehensive list of system and sub-system reliability drivers for any liquid propulsion engine system. We then build a reliability model to parametrically analyze the impact of some reliability parameters. We present sensitivity analysis results for a selected subset of the key reliability drivers using the model. Reliability drivers identified include: number of engines for the liquid propulsion stage, single engine total reliability, engine operation duration, engine thrust size, reusability, engine de-rating or up-rating, engine-out design (including engine-out switching reliability, catastrophic fraction, preventable failure fraction, unnecessary shutdown fraction), propellant specific hazards, engine start and cutoff transient hazards, engine combustion cycles, vehicle and engine interface and interaction hazards, engine health management system, engine modification, engine ground start hold down with launch commit criteria, engine altitude start (1 in. start), Multiple altitude restart (less than 1 restart), component, subsystem and system design, manufacturing/ground operation support/pre and post flight check outs and inspection, extensiveness of the development program. We present some sensitivity analysis results for the following subset of the drivers: number of engines for the propulsion stage, single engine total reliability, engine operation duration, engine de-rating or up-rating requirements, engine-out design, catastrophic fraction, preventable failure fraction, unnecessary shutdown fraction, and engine health management system implementation (basic redlines and more advanced health management systems).
NASA Technical Reports Server (NTRS)
Sankararaman, Shankar
2016-01-01
This paper presents a computational framework for uncertainty characterization and propagation, and sensitivity analysis under the presence of aleatory and epistemic un- certainty, and develops a rigorous methodology for efficient refinement of epistemic un- certainty by identifying important epistemic variables that significantly affect the overall performance of an engineering system. The proposed methodology is illustrated using the NASA Langley Uncertainty Quantification Challenge (NASA-LUQC) problem that deals with uncertainty analysis of a generic transport model (GTM). First, Bayesian inference is used to infer subsystem-level epistemic quantities using the subsystem-level model and corresponding data. Second, tools of variance-based global sensitivity analysis are used to identify four important epistemic variables (this limitation specified in the NASA-LUQC is reflective of practical engineering situations where not all epistemic variables can be refined due to time/budget constraints) that significantly affect system-level performance. The most significant contribution of this paper is the development of the sequential refine- ment methodology, where epistemic variables for refinement are not identified all-at-once. Instead, only one variable is first identified, and then, Bayesian inference and global sensi- tivity calculations are repeated to identify the next important variable. This procedure is continued until all 4 variables are identified and the refinement in the system-level perfor- mance is computed. The advantages of the proposed sequential refinement methodology over the all-at-once uncertainty refinement approach are explained, and then applied to the NASA Langley Uncertainty Quantification Challenge problem.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Olszewski, Mitchell
The U.S. Department of Energy (DOE) and the U.S. Council for Automotive Research (composed of automakers Ford, General Motors, and Chrysler) announced in January 2002 a new cooperative research effort. Known as 'FreedomCAR' (derived from 'Freedom' and 'Cooperative Automotive Research'), it represents DOE's commitment to developing public/private partnerships to fund high-risk, high-payoff research into advanced automotive technologies. Efficient fuel cell technology, which uses hydrogen to power automobiles without air pollution, is a very promising pathway to achieving the ultimate vision. The new partnership replaces and builds upon the Partnership for a New Generation of Vehicles initiative that ran from 1993more » through 2001. The Advanced Power Electronics and Electric Machines (APEEM) subprogram within the FreedomCAR and Vehicle Technologies Program provides support and guidance for many cutting-edge automotive technologies now under development. Research is focused on understanding and improving the way the various new components of tomorrow's automobiles will function as a unified system to improve fuel efficiency. In supporting the development of hybrid propulsion systems, the APEEM effort has enabled the development of technologies that will significantly improve advanced vehicle efficiency, costs, and fuel economy. The APEEM subprogram supports the efforts of the FreedomCAR and Fuel Partnership through a three-phase approach intended to: (1) identify overall propulsion and vehicle-related needs by analyzing programmatic goals and reviewing industry's recommendations and requirements and then develop the appropriate technical targets for systems, subsystems, and component research and development activities; (2) develop and validate individual subsystems and components, including electric motors and power electronics; and (3) determine how well the components and subsystems work together in a vehicle environment or as a complete propulsion system and whether the efficiency and performance targets at the vehicle level have been achieved. The research performed under this subprogram will help remove technical and cost barriers to enable the development of technology for use in such advanced vehicles as hybrid and fuel-cell-powered automobiles that meet the goals of the FreedomCAR and Vehicle Technologies Program. A key element in making hybrid electric vehicles (HEVs) practical is providing an affordable electric traction drive system. This will require attaining weight, volume, and cost targets for the power electronics and electrical machines subsystems of the traction drive system. Areas of development include these: (1) novel traction motor designs that result in increased power density and lower cost; (2) inverter technologies involving new topologies to achieve higher efficiency and the ability to accommodate higher-temperature environments; (3) converter concepts that employ means of reducing the component count and integrating functionality to decrease size, weight, and cost; (4) more effective thermal control and packaging technologies; and (5) integrated motor/inverter concepts. The Oak Ridge National Laboratory's (ORNL's) Power Electronics and Electric Machinery Research Center conducts fundamental research, evaluates hardware, and assists in the technical direction of the DOE Office of FreedomCAR and Vehicle Technologies Program, APEEM subprogram. In this role, ORNL serves on the FreedomCAR Electrical and Electronics Technical Team, evaluates proposals for DOE, and lends its technological expertise to the direction of projects and evaluation of developing technologies. ORNL also executes specific projects for DOE. The following report discusses those projects carried out in FY 2007 and conveys highlights of their accomplishments. Numerous project reviews, technical reports, and papers have been published for these efforts, if the reader is interested in pursuing details of the work.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
LaBrecque, Douglas; Brigham, Russell D.; Schmidt-Hattenburger, Conny
2017-05-01
The proposed system was designed to operate as a permanent, autonomous monitoring and data collection system that can provide much higher temporal data density than can be achieved economically with 3-Dimensional (3D) seismic surveys. It can operate over broad areas for long periods of time providing full 3D data sets on a monthly basis at a very low cost. By borrowing techniques commonly used in marine CSEM, structural information from background seismic surveys can be incorporated into the CSEM modeling to provide high resolution models of CO 2 progression within reservoirs. The system uses borehole-based vertical-electric-dipole sources placed at reservoirmore » depths in the formation. The electric and magnetic fields induced by this source are received on the surface using an array of stations. The project was conducted in three phases. Phase I demonstrated the feasibility of the system to collect static/reference data at the Ketzin CO 2 storage pilot site in Germany. In Phase I, numerical modeling was used to determine the optimal configurations and requirements for sensor sensitivity and data accuracy. Based on the model results, existing hardware and software were modified. The CSEM system was then field tested at the Ketzin site. The data were imaged and the results were compared with independent studies of the reservoir and overburden geo-electrical characteristics. Phase II demonstrated the ability to provide sensitive, cost-effective measurement of changes in reservoir properties and changes in the overlying formations using a second round of measurements at the Ketzin site. A prototype autonomous recording system was developed and tested as a subset of the measurement points. Phase III of the project quantified the advantages (and disadvantages) of the fully autonomous data collection subsystems by comparing them with repeated measurements made with mobile stations. The Phase III also provided an additional time point in measuring post-closure changes in and above the Ketzin CO 2 injection site. Validation of the CSEM field survey results were completed using a method such as other alternative and available field site data.« less
NASA Technical Reports Server (NTRS)
1983-01-01
The technical effort associated with the selection and definition of the recommended SRB-X concept is documented. Included are discussions concerning the trades leading to the selected concept, the analysis that established the concept's basic subsystem characteristics, selected configuration description and performance capabilities, launch site operations and facility needs, development schedule, cost characteristics, risk assessment, and a cursory comparison with other launch systems.
1984-12-01
operating results (income statement) and financial condition ( balance sheet) are developed. From this data, stabilized rates are developed and adjusted to...funding budgets based on projected workloads developed at workload conferences. The workload subsystem distributes and balances projected manhours at...is the validation criteria. However, any account with a credit balance is deleted from the UCA data which causes a minor but identifiable
Proceedings: Outer Planet Probe Technology Workshop, summary volume
NASA Technical Reports Server (NTRS)
1974-01-01
A summary report and overview of the Outer Planet Probe Technology Conference are given. Summary data cover: (1) state of the art concerning mission definitions, probe requirements, systems, subsystems, and mission peculiar hardware, (2) mission and equipment trade-offs associated with Saturn/Uranus baseline configuration and the influence of Titan and Jupiter options on mission performance and costs, and (3) identification of critically required future R and D activities.
1975-10-01
VINSON, JR. ^ Major General, GS Deputy Chief of Staff for Combat Developments CF: w incl HQDA ( DAHO -SGTF) - 15 HQDA (DAMO-RQC) - 1 HQDA (DAMO...TC) - 1 HQDA (DAMO-ZD) - 1 HQDA ( DAhO -FI) - 1 HQDA (DALO) - 1 HQDA (DAMA-CS) - 1 HQDA (DACA) - 1 HQDA (DAPE) - 1 HQDA (DUSA(OR)) - 1 Cdr AMC
Systems Engineering Programmatic Estimation Using Technology Variance
NASA Technical Reports Server (NTRS)
Mog, Robert A.
2000-01-01
Unique and innovative system programmatic estimation is conducted using the variance of the packaged technologies. Covariance analysis is performed on the subsystems and components comprising the system of interest. Technological "return" and "variation" parameters are estimated. These parameters are combined with the model error to arrive at a measure of system development stability. The resulting estimates provide valuable information concerning the potential cost growth of the system under development.
Conceptual design study. Science and Applications Space Platform (SASP). Final briefing
NASA Technical Reports Server (NTRS)
1980-01-01
The modularity, shape, and size of the recommended platform concept offers a low investment, early option to demonstrate the system; flexibility to conservative growth; adaptability to great variety of multi or dedicated payload groups; and good dispersion and viewing freedom for payloads. Platform configuration effectively supports 80 to 85% of the NASA/OSS and OSTA payloads. The subsystem approaches recommended are based on cost effective distribution of functions.
Real-time compression of raw computed tomography data: technology, architecture, and benefits
NASA Astrophysics Data System (ADS)
Wegener, Albert; Chandra, Naveen; Ling, Yi; Senzig, Robert; Herfkens, Robert
2009-02-01
Compression of computed tomography (CT) projection samples reduces slip ring and disk drive costs. A lowcomplexity, CT-optimized compression algorithm called Prism CTTM achieves at least 1.59:1 and up to 2.75:1 lossless compression on twenty-six CT projection data sets. We compare the lossless compression performance of Prism CT to alternative lossless coders, including Lempel-Ziv, Golomb-Rice, and Huffman coders using representative CT data sets. Prism CT provides the best mean lossless compression ratio of 1.95:1 on the representative data set. Prism CT compression can be integrated into existing slip rings using a single FPGA. Prism CT decompression operates at 100 Msamp/sec using one core of a dual-core Xeon CPU. We describe a methodology to evaluate the effects of lossy compression on image quality to achieve even higher compression ratios. We conclude that lossless compression of raw CT signals provides significant cost savings and performance improvements for slip rings and disk drive subsystems in all CT machines. Lossy compression should be considered in future CT data acquisition subsystems because it provides even more system benefits above lossless compression while achieving transparent diagnostic image quality. This result is demonstrated on a limited dataset using appropriately selected compression ratios and an experienced radiologist.
MEMS for pico- to micro-satellites
NASA Astrophysics Data System (ADS)
Shea, H. R.
2009-02-01
MEMS sensors, actuators, and sub-systems can enable an important reduction in the size and mass of spacecrafts, first by replacing larger and heavier components, then by replacing entire subsystems, and finally by enabling the microfabrication of highly integrated picosats. Very small satellites (1 to 100 kg) stand to benefit the most from MEMS technologies. These small satellites are typically used for science or technology demonstration missions, with higher risk tolerance than multi-ton telecommunication satellites. While MEMS are playing a growing role on Earth in safety-critical applications, in the harsh and remote environment of space, reliability is still the crucial issue, and the absence of an accepted qualification methodology is holding back MEMS from wider use. An overview is given of the range of MEMS applications in space. An effective way to prove that MEMS can operate reliably in space is to use them in space: we illustrate how Cubesats (1 kg, 1 liter, cubic satellites in a standardized format to reduce launch costs) can serve as low-cost vectors for MEMS technology demonstration in space. The Cubesat SwissCube developed in Switzerland is used as one example of a rapid way to fly new microtechnologies, and also as an example of a spacecraft whose performance is only possible thanks to MEMS.
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
1980-07-01
This document is the final report of the solar energy heating and hot water system installed at the Kansas City Fire Station, Number 24, 2309 Hardesty Street, Kansas City, Missouri. The solar system was designed to provide 47 percent of the space heating, 8800 square feet area and 75 percent of the domestic hot water (DHW) load. The solar system consists of 2808 square feet of Solaron, model 2001, air, flat plate collector subsystem, a concrete box storage subsystem which contains 1428 cubic feet of 1/2 inch diameter pebbles weighing 71 1/2 tons, a DHW preheat tank, blowers, pumps, heatmore » exchangers, air ducting, controls and associated plumbing. Two 120-gallon electric DHW heaters supply domestic hot water which is preheated by the solar system. Auxiliary space heating is provided by three electric heat pumps with electric resistance heaters and four 30-kilowatt electric unit heaters. There are six modes of system operation. This project is part of the Department of Energy PON-1 Solar Demonstration Program with DOE cost sharing $154,282 of the $174,372 solar system cost. The Final Design Review was held March 1977, the system became operational March 1979 and acceptance test was completed in September 1979.« less
Plug-and-play design approach to smart harness for modular small satellites
NASA Astrophysics Data System (ADS)
Mughal, M. Rizwan; Ali, Anwar; Reyneri, Leonardo M.
2014-02-01
A typical satellite involves many different components that vary in bandwidth demand. Sensors that require a very low data rate may reside on a simple two- or three-wire interface such as I2C, SPI, etc. Complex sensors that require high data rate and bandwidth may reside on an optical interface. The AraMiS architecture is an enhanced capability architecture with different satellite configurations. Although keeping the low-cost and COTS approach of CubeSats, it extends the modularity concept as it also targets different satellite shapes and sizes. But modularity moves beyond the mechanical structure: the tiles also have thermo-mechanical, harness and signal-processing functionalities. Further modularizing the system, every tile can also host a variable number of small sensors, actuators or payloads, connected using a plug-and-play approach. Every subsystem is housed in a small daughter board and is supplied, by the main tile, with power and data distribution functions, power and data harness, mechanical support and is attached and interconnected with space-grade spring-loaded connectors. The tile software is also modular and allows a quick adaptation to specific subsystems. The basic software for the CPU is properly hardened to guarantee high level of radiation tolerance at very low cost.
NASA Technical Reports Server (NTRS)
Jandura, Louise
2010-01-01
The Sample Acquisition/Sample Processing and Handling subsystem for the Mars Science Laboratory is a highly-mechanized, Rover-based sampling system that acquires powdered rock and regolith samples from the Martian surface, sorts the samples into fine particles through sieving, and delivers small portions of the powder into two science instruments inside the Rover. SA/SPaH utilizes 17 actuated degrees-of-freedom to perform the functions needed to produce 5 sample pathways in support of the scientific investigation on Mars. Both hardware redundancy and functional redundancy are employed in configuring this sampling system so some functionality is retained even with the loss of a degree-of-freedom. Intentional dynamic environments are created to move sample while vibration isolators attenuate this environment at the sensitive instruments located near the dynamic sources. In addition to the typical flight hardware qualification test program, two additional types of testing are essential for this kind of sampling system: characterization of the intentionally-created dynamic environment and testing of the sample acquisition and processing hardware functions using Mars analog materials in a low pressure environment. The overall subsystem design and configuration are discussed along with some of the challenges, tradeoffs, and lessons learned in the areas of fault tolerance, intentional dynamic environments, and special testing
Portable Fourier Transform Spectroscopy for Analysis of Surface Contamination and Quality Control
NASA Technical Reports Server (NTRS)
Pugel, Diane
2012-01-01
Progress has been made into adapting and enhancing a commercially available infrared spectrometer for the development of a handheld device for in-field measurements of the chemical composition of various samples of materials. The intent is to duplicate the functionality of a benchtop Fourier transform infrared spectrometer (FTIR) within the compactness of a handheld instrument with significantly improved spectral responsivity. Existing commercial technology, like the deuterated L-alanine triglycine sulfide detectors (DLATGS), is capable of sensitive in-field chemical analysis. This proposed approach compares several subsystem elements of the FTIR inside of the commercial, non-benchtop system to the commercial benchtop systems. These subsystem elements are the detector, the preamplifier and associated electronics of the detector, the interferometer, associated readout parameters, and cooling. This effort will examine these different detector subsystem elements to look for limitations in each. These limitations will be explored collaboratively with the commercial provider, and will be prioritized to meet the deliverable objectives. The tool design will be that of a handheld gun containing the IR filament source and associated optics. It will operate in a point-and-shoot manner, pointing the source and optics at the sample under test and capturing the reflected response of the material in the same handheld gun. Data will be captured via the gun and ported to a laptop.
IDEAS: A multidisciplinary computer-aided conceptual design system for spacecraft
NASA Technical Reports Server (NTRS)
Ferebee, M. J., Jr.
1984-01-01
During the conceptual development of advanced aerospace vehicles, many compromises must be considered to balance economy and performance of the total system. Subsystem tradeoffs may need to be made in order to satisfy system-sensitive attributes. Due to the increasingly complex nature of aerospace systems, these trade studies have become more difficult and time-consuming to complete and involve interactions of ever-larger numbers of subsystems, components, and performance parameters. The current advances of computer-aided synthesis, modeling and analysis techniques have greatly helped in the evaluation of competing design concepts. Langley Research Center's Space Systems Division is currently engaged in trade studies for a variety of systems which include advanced ground-launched space transportation systems, space-based orbital transfer vehicles, large space antenna concepts and space stations. The need for engineering analysis tools to aid in the rapid synthesis and evaluation of spacecraft has led to the development of the Interactive Design and Evaluation of Advanced Spacecraft (IDEAS) computer-aided design system. The ADEAS system has been used to perform trade studies of competing technologies and requirements in order to pinpoint possible beneficial areas for research and development. IDEAS is presented as a multidisciplinary tool for the analysis of advanced space systems. Capabilities range from model generation and structural and thermal analysis to subsystem synthesis and performance analysis.
DKIST facility management system integration
NASA Astrophysics Data System (ADS)
White, Charles R.; Phelps, LeEllen
2016-07-01
The Daniel K. Inouye Solar Telescope (DKIST) Observatory is under construction at Haleakalā, Maui, Hawai'i. When complete, the DKIST will be the largest solar telescope in the world. The Facility Management System (FMS) is a subsystem of the high-level Facility Control System (FCS) and directly controls the Facility Thermal System (FTS). The FMS receives operational mode information from the FCS while making process data available to the FCS and includes hardware and software to integrate and control all aspects of the FTS including the Carousel Cooling System, the Telescope Chamber Environmental Control Systems, and the Temperature Monitoring System. In addition it will integrate the Power Energy Management System and several service systems such as heating, ventilation, and air conditioning (HVAC), the Domestic Water Distribution System, and the Vacuum System. All of these subsystems must operate in coordination to provide the best possible observing conditions and overall building management. Further, the FMS must actively react to varying weather conditions and observational requirements. The physical impact of the facility must not interfere with neighboring installations while operating in a very environmentally and culturally sensitive area. The FMS system will be comprised of five Programmable Automation Controllers (PACs). We present a pre-build overview of the functional plan to integrate all of the FMS subsystems.
PFERD Mission: Pluto Flyby Exploration/Research Design
NASA Technical Reports Server (NTRS)
Lemke, Gary; Zayed, Husni; Herring, Jason; Fuehne, Doug; Sutton, Kevin; Sharkey, Mike
1990-01-01
The Pluto Flyby Exploration/Research Design (PFERD) mission will consist of a flyby spacecraft to Pluto and its satellite, Charon. The mission lifetime is expected to be 18 years. The Titan 4 with a Centaur upper stage will be utilized to launch the craft into the transfer orbit. The proposal was divided into six main subsystems: (1) scientific instrumentation; (2) command, communications, and control: (3) altitude and articulation control; (4) power and propulsion; (5) structures and thermal control; and (6) mission management and costing. Tradeoff studies were performed to optimize all factors of design, including survivability, performance, cost, and weight. Problems encountered in the design are also presented.
NASA Technical Reports Server (NTRS)
1983-01-01
An overview of the basic space station infrastructure is presented. A strong case is made for the evolution of the station using the basic Space Transportation System (STS) to achieve a smooth transition and cost effective implementation. The integrated logistics support (ILS) element of the overall station infrastructure is investigated. The need for an orbital transport system capability that is the key to servicing and spacecraft positioning scenarios and associated mission needs is examined. Communication is also an extremely important element and the basic issue of station autonomy versus ground support effects the system and subsystem architecture.
Aerospace Vehicle Design, Spacecraft Section. Final Project Reports. Volume 2; Project Groups 6-8
NASA Technical Reports Server (NTRS)
1989-01-01
Three groups of student engineers in an aerospace vehicle design course present their designs for a vehicle that can be used to resupply the Space Station Freedam and provide emergency crew return to earth capability. The vehicle's requirements include a lifetime that exceeds six years, low cost, the capability for withstanding pressurization, launch, orbit, and reentry hazards, and reliability. The vehicle's subsystems are structures, communication and command data systems, attitude and articulation control, life support and crew systems, power and propulsion, reentry and recovery systems, and mission management, planning, and costing. Special attention is given to spacecraft communications.
NASA Technical Reports Server (NTRS)
Levack, Daniel J. H.
2000-01-01
The Alternate Propulsion Subsystem Concepts contract had seven tasks defined that are reported under this contract deliverable. The tasks were: FAA Restart Study, J-2S Restart Study, Propulsion Database Development. SSME Upper Stage Use. CERs for Liquid Propellant Rocket Engines. Advanced Low Cost Engines, and Tripropellant Comparison Study. The two restart studies, F-1A and J-2S, generated program plans for restarting production of each engine. Special emphasis was placed on determining changes to individual parts due to obsolete materials, changes in OSHA and environmental concerns, new processes available, and any configuration changes to the engines. The Propulsion Database Development task developed a database structure and format which is easy to use and modify while also being comprehensive in the level of detail available. The database structure included extensive engine information and allows for parametric data generation for conceptual engine concepts. The SSME Upper Stage Use task examined the changes needed or desirable to use the SSME as an upper stage engine both in a second stage and in a translunar injection stage. The CERs for Liquid Engines task developed qualitative parametric cost estimating relationships at the engine and major subassembly level for estimating development and production costs of chemical propulsion liquid rocket engines. The Advanced Low Cost Engines task examined propulsion systems for SSTO applications including engine concept definition, mission analysis. trade studies. operating point selection, turbomachinery alternatives, life cycle cost, weight definition. and point design conceptual drawings and component design. The task concentrated on bipropellant engines, but also examined tripropellant engines. The Tripropellant Comparison Study task provided an unambiguous comparison among various tripropellant implementation approaches and cycle choices, and then compared them to similarly designed bipropellant engines in the SSTO mission This volume overviews each of the tasks giving its objectives, main results. and conclusions. More detailed Final Task Reports are available on each individual task.
Independent Orbiter Assessment (IOA): CIL issues resolution report, volume 2
NASA Technical Reports Server (NTRS)
1988-01-01
The results of the Independent Orbiter Assessment (IOA) of the Failure Modes And Effects Analysis (FMEA) and Critical Items List (CIL) are presented. This report contains IOA assessment worksheets showing resolution of outstanding IOA CIL issues that were summarized in the IOA FMEA/CIL Assessment Interim Report, dated 9 March 1988. Each assessment worksheet has been updated with CIL issue resolution and rationale. Volume 2 contains the worksheets for the following subsystems: Nose Wheel Steering Subsystem; Remote Manipulator Subsystem; Atmospheric Revitalization Subsystem; Extravehicular Mobility Unit Subsystem; Power Reactant Supply and Distribution Subsystem; Main Propulsion Subsystem; and Orbital Maneuvering Subsystem.
Secure video communications system
Smith, Robert L.
1991-01-01
A secure video communications system having at least one command network formed by a combination of subsystems. The combination of subsystems to include a video subsystem, an audio subsystem, a communications subsystem, and a control subsystem. The video communications system to be window driven and mouse operated, and having the ability to allow for secure point-to-point real-time teleconferencing.
Modular space station phase B extension, preliminary system design. Volume 4: Subsystems analyses
NASA Technical Reports Server (NTRS)
Antell, R. W.
1972-01-01
The subsystems tradeoffs, analyses, and preliminary design results are summarized. Analyses were made of the structural and mechanical, environmental control and life support, electrical power, guidance and control, reaction control, information, and crew habitability subsystems. For each subsystem a summary description is presented including subsystem requirements, subsystem description, and subsystem characteristics definition (physical, performance, and interface). The major preliminary design data and tradeoffs or analyses are described in detail at each of the assembly levels.
Some recent developments in spacecraft environmental control/life support subsystems
NASA Technical Reports Server (NTRS)
Gillen, R. J.; Olcott, T. M.
1974-01-01
The subsystems considered include a flash evaporator for heat rejection, a regenerable carbon dioxide and humidity control subsystem, an iodinating subsystem for potable water, a cabin contaminant control subsystem, and a wet oxidation subsystem for processing spacecraft wastes. The flash evaporator discussed is a simple unit which efficiently controls life support system temperatures over a wide range of heat loads. For certain advanced spacecraft applications the control of cabin carbon dioxide and humidity can be successfully achieved by a regenerable solid amine subsystem.
On the mechanism of chromophototherapy used in sports medicine and rehabilitation
NASA Astrophysics Data System (ADS)
Tang, Mian; Liu, Timon C.
2005-01-01
Light is the primary stimulus for regulating circadian rhythms, seasonal cycles, and neuroendocrine responses in many species, including humans. The major circadian pacemaker in the hypothalamic suprachiasmatic nucleus is entrained to the light/dark cycles from the outside world by circadian photoreceptors which are functionally characterized by the direct sensitivity to light with broad spectrum and the relatively high stability. Chromophototherapy mediated by the color indirect effect (CIE), the physiological and psychological effects of color resulting from color vision, is functionally characterized by the sensitivity to light with narrow spectrum and the relatively low stability. In this paper, the mechanism of chromophototherapy used in sports medicine and rehabilitation, especially in treating overtraining syndrome (OTS), was discussed. Although several hypotheses and the corresponding OTS treatments have been proposed, each only explains and treats a selective aspect of OTS. On the one hand, an autonomic or neuroendocrine imbalance is hypothesized as underlying by Lehmann et al so that the described functional alterations of pituitary-adrenal axis and sympathetic system can explain persistent performance incompetence in affected athletes beside additional mechanisms. On the other hand, cold color (green, blue or violet) excites parasympathetic subsystem and hot color (red, orange or yellow) excites sympathetic subsystem for chromophototherapy. The conclusion was then drawn that chromophototherapy might be a good therapy to treat OTS.
NASA Technical Reports Server (NTRS)
Levak, Daniel
1993-01-01
The objective of this contract was to provide definition of alternate propulsion systems for both earth-to-orbit (ETO) and in-space vehicles (upper stages and space transfer vehicles). For such propulsion systems, technical data to describe performance, weight, dimensions, etc. was provided along with programmatic information such as cost, schedule, needed facilities, etc. Advanced technology and advanced development needs were determined and provided. This volume separately presents the various program cost estimates that were generated under three tasks: the F-1A Restart Task, the J-2S Restart Task, and the SSME Upper Stage Use Task. The conclusions, technical results, and the program cost estimates are described in more detail in Volume 1 - Executive Summary and in individual Final Task Reports.
Emergence of homeostasis and “noise imprinting” in an evolution model
Stern, Michael D.
1999-01-01
Homeostasis, the creation of a stabilized internal milieu, is ubiquitous in biological evolution, despite the entropic cost of excluding noise information from a region. The advantages of stability seem self evident, but the alternatives are not so clear. This issue was studied by means of numerical experiments on a simple evolution model: a population of Boolean network “organisms” selected for performance of a curve-fitting task while subjected to noise. During evolution, noise sensitivity increased with fitness. Noise exclusion evolved spontaneously, but only if the noise was sufficiently unpredictable. Noise that was limited to one or a few stereotyped patterns caused symmetry breaking that prevented noise exclusion. Instead, the organisms incorporated the noise into their function at little cost in ultimate fitness and became totally noise dependent. This “noise imprinting” suggests caution when interpreting apparent adaptations seen in nature. If the noise was totally random from generation to generation, noise exclusion evolved reliably and irreversibly, but if the noise was correlated over several generations, maladaptive selection of noise-dependent traits could reverse noise exclusion, with catastrophic effect on population fitness. Noise entering the selection process rather than the organism had a different effect: adaptive evolution was totally abolished above a critical noise amplitude, in a manner resembling a thermodynamic phase transition. Evolutionary adaptation to noise involves the creation of a subsystem screened from noise information but increasingly vulnerable to its effects. Similar considerations may apply to information channeling in human cultural evolution. PMID:10485897
Air and water quality monitor assessment of life support subsystems
NASA Technical Reports Server (NTRS)
Whitley, Ken; Carrasquillo, Robyn L.; Holder, D.; Humphries, R.
1988-01-01
Preprotype air revitalization and water reclamation subsystems (Mole Sieve, Sabatier, Static Feed Electrolyzer, Trace Contaminant Control, and Thermoelectric Integrated Membrane Evaporative Subsystem) were operated and tested independently and in an integrated arrangement. During each test, water and/or gas samples were taken from each subsystem so that overall subsystem performance could be determined. The overall test design and objectives for both subsystem and integrated subsystem tests were limited, and no effort was made to meet water or gas specifications. The results of chemical analyses for each of the participating subsystems are presented along with other selected samples which were analyzed for physical properties and microbiologicals.
Projection of distributed-collector solar-thermal electric power plant economics to years 1990-2000
NASA Technical Reports Server (NTRS)
Fujita, T.; Elgabalawi, N.; Herrera, G.; Turner, R. H.
1977-01-01
A preliminary comparative evaluation of distributed-collector solar thermal power plants was undertaken by projecting power plant economics of selected systems to the 1990 to 2000 time frame. The selected systems include: (1) fixed orientation collectors with concentrating reflectors and vacuum tube absorbers, (2) one axis tracking linear concentrator including parabolic trough and variable slat designs, and (3) two axis tracking parabolic dish systems including concepts with small heat engine-electric generator assemblies at each focal point as well as approaches having steam generators at the focal point with pipeline collection to a central power conversion unit. Comparisons are presented primarily in terms of energy cost and capital cost over a wide range of operating load factors. Sensitvity of energy costs for a range of efficiency and cost of major subsystems/components is presented to delineate critical technological development needs.
NASA Technical Reports Server (NTRS)
Rosenberg, L. S.; Revere, W. R.; Selcuk, M. K.
1981-01-01
A computer simulation code was employed to evaluate several generic types of solar power systems (up to 10 MWe). Details of the simulation methodology, and the solar plant concepts are given along with cost and performance results. The Solar Energy Simulation computer code (SESII) was used, which optimizes the size of the collector field and energy storage subsystem for given engine-generator and energy-transport characteristics. Nine plant types were examined which employed combinations of different technology options, such as: distributed or central receivers with one- or two-axis tracking or no tracking; point- or line-focusing concentrator; central or distributed power conversion; Rankin, Brayton, or Stirling thermodynamic cycles; and thermal or electrical storage. Optimal cost curves were plotted as a function of levelized busbar energy cost and annualized plant capacity. Point-focusing distributed receiver systems were found to be most efficient (17-26 percent).
The Human Subsystem - Definition and Integration
NASA Technical Reports Server (NTRS)
vonBengston, Kristian; Twyford, Evan
2007-01-01
This paper will discuss the use of the human subsystem in development phases of human space flight. Any space mission has clearly defined subsystems, managed by experts attached to these. Clearly defined subsystems and correct use provide easier and more efficient development for each independent subsystem and for the relation between these subsystems. Furthermore, this paper will argue that a defined subsystem related to humans in space has not always been clearly present, and that correct implementation is perhaps missing, based on experience and survey data. Finally, the authors will discuss why the human subsystem has not been fully integrated, why it must be a mandatory part of the programming, a re-definition of the human subsystem, and suggestions of methods to improve the integration of human factors in the development.
Virtual Habitat -a dynamic simulation of closed life support systems -human model status
NASA Astrophysics Data System (ADS)
Markus Czupalla, M. Sc.; Zhukov, Anton; Hwang, Su-Au; Schnaitmann, Jonas
In order to optimize Life Support Systems on a system level, stability questions must be in-vestigated. To do so the exploration group of the Technical University of Munich (TUM) is developing the "Virtual Habitat" (V-HAB) dynamic LSS simulation software. V-HAB shall provide the possibility to conduct dynamic simulations of entire mission scenarios for any given LSS configuration. The Virtual Habitat simulation tool consists of four main modules: • Closed Environment Module (CEM) -monitoring of compounds in a closed environment • Crew Module (CM) -dynamic human simulation • P/C Systems Module (PCSM) -dynamic P/C subsystems • Plant Module (PM) -dynamic plant simulation The core module of the simulation is the dynamic and environment sensitive human module. Introduced in its basic version in 2008, the human module has been significantly updated since, increasing its capabilities and maturity significantly. In this paper three newly added human model subsystems (thermal regulation, digestion and schedule controller) are introduced touching also on the human stress subsystem which is cur-rently under development. Upon the introduction of these new subsystems, the integration of these into the overall V-HAB human model is discussed, highlighting the impact on the most important I/F. The overall human model capabilities shall further be summarized and presented based on meaningful test cases. In addition to the presentation of the results, the correlation strategy for the Virtual Habitat human model shall be introduced assessing the models current confidence level and giving an outlook on the future correlation strategy. Last but not least, the remaining V-HAB mod-ules shall be introduced shortly showing how the human model is integrated into the overall simulation.
On the subsystem formulation of linear-response time-dependent DFT.
Pavanello, Michele
2013-05-28
A new and thorough derivation of linear-response subsystem time-dependent density functional theory (TD-DFT) is presented and analyzed in detail. Two equivalent derivations are presented and naturally yield self-consistent subsystem TD-DFT equations. One reduces to the subsystem TD-DFT formalism of Neugebauer [J. Chem. Phys. 126, 134116 (2007)]. The other yields Dyson type equations involving three types of subsystem response functions: coupled, uncoupled, and Kohn-Sham. The Dyson type equations for subsystem TD-DFT are derived here for the first time. The response function formalism reveals previously hidden qualities and complications of subsystem TD-DFT compared with the regular TD-DFT of the supersystem. For example, analysis of the pole structure of the subsystem response functions shows that each function contains information about the electronic spectrum of the entire supersystem. In addition, comparison of the subsystem and supersystem response functions shows that, while the correlated response is subsystem additive, the Kohn-Sham response is not. Comparison with the non-subjective partition DFT theory shows that this non-additivity is largely an artifact introduced by the subjective nature of the density partitioning in subsystem DFT.