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Sample records for spacecraft processing directorate

  1. Board Directors' Selection Process Following a Gender Quota

    Sigurjonsson, Olaf; Arnardottir, Audur Arna

    -quota selection of new board directors as well as the attitudes of board members towards the quota and perceptions of the effect of quota on processes. We incorporate a dual qualitative and quantitative methodology with in-depth interviews with 20 board directors and chairs, and a survey of 260 directors who...... companies with 50 or more employees. Thereby legislatively going further than any other country, out of the fifteen that have amended and adopted gender quota legislation. This article utilizes resource dependency and status expectations theory lenses to explore how the new legislation affected the post...... conviction. Furthermore, there are different avenues to the board. Although initial attitudes towards quotas are more negative among men than women, these attitudes decrease over time. Finally, consistent with status expectation theory, male directors are more negative than their female counterparts about...

  2. The JSC Engineering Directorate Product Peer Review Process

    Jenks, Kenneth C.

    2009-01-01

    The JSC Engineering Directorate has developed a Product Peer Review process in support of NASA policies for project management and systems engineering. The process complies with the requirements of NPR 7120.5, NPR 7123.1 and NPR 7150.2 and follows the guidance in NASA/SP-2007-6105. This presentation will give an overview of the process followed by a brief demonstration of an actual peer review, with audience participation.

  3. Multi-kilowatt modularized spacecraft power processing system development

    Andrews, R.E.; Hayden, J.H.; Hedges, R.T.; Rehmann, D.W.

    1975-07-01

    A review of existing information pertaining to spacecraft power processing systems and equipment was accomplished with a view towards applicability to the modularization of multi-kilowatt power processors. Power requirements for future spacecraft were determined from the NASA mission model-shuttle systems payload data study which provided the limits for modular power equipment capabilities. Three power processing systems were compared to evaluation criteria to select the system best suited for modularity. The shunt regulated direct energy transfer system was selected by this analysis for a conceptual design effort which produced equipment specifications, schematics, envelope drawings, and power module configurations

  4. Laboratory Spacecraft Data Processing and Instrument Autonomy: AOSAT as Testbed

    Lightholder, Jack; Asphaug, Erik; Thangavelautham, Jekan

    2015-11-01

    Recent advances in small spacecraft allow for their use as orbiting microgravity laboratories (e.g. Asphaug and Thangavelautham LPSC 2014) that will produce substantial amounts of data. Power, bandwidth and processing constraints impose limitations on the number of operations which can be performed on this data as well as the data volume the spacecraft can downlink. We show that instrument autonomy and machine learning techniques can intelligently conduct data reduction and downlink queueing to meet data storage and downlink limitations. As small spacecraft laboratory capabilities increase, we must find techniques to increase instrument autonomy and spacecraft scientific decision making. The Asteroid Origins Satellite (AOSAT) CubeSat centrifuge will act as a testbed for further proving these techniques. Lightweight algorithms, such as connected components analysis, centroid tracking, K-means clustering, edge detection, convex hull analysis and intelligent cropping routines can be coupled with the tradition packet compression routines to reduce data transfer per image as well as provide a first order filtering of what data is most relevant to downlink. This intelligent queueing provides timelier downlink of scientifically relevant data while reducing the amount of irrelevant downlinked data. Resulting algorithms allow for scientists to throttle the amount of data downlinked based on initial experimental results. The data downlink pipeline, prioritized for scientific relevance based on incorporated scientific objectives, can continue from the spacecraft until the data is no longer fruitful. Coupled with data compression and cropping strategies at the data packet level, bandwidth reductions exceeding 40% can be achieved while still downlinking data deemed to be most relevant in a double blind study between scientist and algorithm. Applications of this technology allow for the incorporation of instrumentation which produces significant data volumes on small spacecraft

  5. Materials and processes for spacecraft and high reliability applications

    D Dunn, Barrie

    2016-01-01

    The objective of this book is to assist scientists and engineers select the ideal material or manufacturing process for particular applications; these could cover a wide range of fields, from light-weight structures to electronic hardware. The book will help in problem solving as it also presents more than 100 case studies and failure investigations from the space sector that can, by analogy, be applied to other industries. Difficult-to-find material data is included for reference. The sciences of metallic (primarily) and organic materials presented throughout the book demonstrate how they can be applied as an integral part of spacecraft product assurance schemes, which involve quality, material and processes evaluations, and the selection of mechanical and component parts. In this successor edition, which has been revised and updated, engineering problems associated with critical spacecraft hardware and the space environment are highlighted by over 500 illustrations including micrographs and fractographs. Sp...

  6. Spacecraft Testing Programs: Adding Value to the Systems Engineering Process

    Britton, Keith J.; Schaible, Dawn M.

    2011-01-01

    Testing has long been recognized as a critical component of spacecraft development activities - yet many major systems failures may have been prevented with more rigorous testing programs. The question is why is more testing not being conducted? Given unlimited resources, more testing would likely be included in a spacecraft development program. Striking the right balance between too much testing and not enough has been a long-term challenge for many industries. The objective of this paper is to discuss some of the barriers, enablers, and best practices for developing and sustaining a strong test program and testing team. This paper will also explore the testing decision factors used by managers; the varying attitudes toward testing; methods to develop strong test engineers; and the influence of behavior, culture and processes on testing programs. KEY WORDS: Risk, Integration and Test, Validation, Verification, Test Program Development

  7. Modeling the fundamental characteristics and processes of the spacecraft functioning

    Bazhenov, V. I.; Osin, M. I.; Zakharov, Y. V.

    1986-01-01

    The fundamental aspects of modeling of spacecraft characteristics by using computing means are considered. Particular attention is devoted to the design studies, the description of physical appearance of the spacecraft, and simulated modeling of spacecraft systems. The fundamental questions of organizing the on-the-ground spacecraft testing and the methods of mathematical modeling were presented.

  8. Thermal control system. [removing waste heat from industrial process spacecraft

    Hewitt, D. R. (Inventor)

    1983-01-01

    The temperature of an exothermic process plant carried aboard an Earth orbiting spacecraft is regulated using a number of curved radiator panels accurately positioned in a circular arrangement to form an open receptacle. A module containing the process is insertable into the receptacle. Heat exchangers having broad exterior surfaces extending axially above the circumference of the module fit within arcuate spacings between adjacent radiator panels. Banks of variable conductance heat pipes partially embedded within and thermally coupled to the radiator panels extend across the spacings and are thermally coupled to broad exterior surfaces of the heat exchangers by flanges. Temperature sensors monitor the temperature of process fluid flowing from the module through the heat exchanges. Thermal conduction between the heat exchangers and the radiator panels is regulated by heating a control fluid within the heat pipes to vary the effective thermal length of the heat pipes in inverse proportion to changes in the temperature of the process fluid.

  9. Evaluation of Brine Processing Technologies for Spacecraft Wastewater

    Shaw, Hali L.; Flynn, Michael; Wisniewski, Richard; Lee, Jeffery; Jones, Harry; Delzeit, Lance; Shull, Sarah; Sargusingh, Miriam; Beeler, David; Howard, Jeanie; hide

    2015-01-01

    Brine drying systems may be used in spaceflight. There are several advantages to using brine processing technologies for long-duration human missions including a reduction in resupply requirements and achieving high water recovery ratios. The objective of this project was to evaluate four technologies for the drying of spacecraft water recycling system brine byproducts. The technologies tested were NASA's Forward Osmosis Brine Drying (FOBD), Paragon's Ionomer Water Processor (IWP), NASA's Brine Evaporation Bag (BEB) System, and UMPQUA's Ultrasonic Brine Dewatering System (UBDS). The purpose of this work was to evaluate the hardware using feed streams composed of brines similar to those generated on board the International Space Station (ISS) and future exploration missions. The brine formulations used for testing were the ISS Alternate Pretreatment and Solution 2 (Alt Pretreat). The brines were generated using the Wiped-film Rotating-disk (WFRD) evaporator, which is a vapor compression distillation system that is used to simulate the function of the ISS Urine Processor Assembly (UPA). Each system was evaluated based on the results from testing and Equivalent System Mass (ESM) calculations. A Quality Function Deployment (QFD) matrix was also developed as a method to compare the different technologies based on customer and engineering requirements.

  10. Educational Data Processing Directors' Perceptions of Technological Training Priorities for School Administrators.

    Bozeman, W. C.; Spuck, D. W.

    Results of a survey of school district data processing directors' attitudes toward the content of technology curriculum in educational administrator training programs are presented in this paper. Questionnaires sent to 152 large school districts yielded 78 usable returns, a 51 percent response rate. Respondents rated the following topics as most…

  11. Coordinated polar spacecraft, geosynchronous spacecraft, and ground-based observations of magnetopause processes and their coupling to the ionosphere

    G. Le

    2004-12-01

    Full Text Available In this paper, we present in-situ observations of processes occurring at the magnetopause and vicinity, including surface waves, oscillatory magnetospheric field lines, and flux transfer events, and coordinated observations at geosynchronous orbit by the GOES spacecraft, and on the ground by CANOPUS and 210° Magnetic Meridian (210MM magnetometer arrays. On 7 February 2002, during a high-speed solar wind stream, the Polar spacecraft was skimming the magnetopause in a post-noon meridian plane for ~3h. During this interval, it made two short excursions and a few partial crossings into the magnetosheath and observed quasi-periodic cold ion bursts in the region adjacent to the magnetopause current layer. The multiple magnetopause crossings, as well as the velocity of the cold ion bursts, indicate that the magnetopause was oscillating with an ~6-min period. Simultaneous observations of Pc5 waves at geosynchronous orbit by the GOES spacecraft and on the ground by the CANOPUS magnetometer array reveal that these magnetospheric pulsations were forced oscillations of magnetic field lines directly driven by the magnetopause oscillations. The magnetospheric pulsations occurred only in a limited longitudinal region in the post-noon dayside sector, and were not a global phenomenon, as one would expect for global field line resonance. Thus, the magnetopause oscillations at the source were also limited to a localized region spanning ~4h in local time. These observations suggest that it is unlikely that the Kelvin-Helmholz instability and/or fluctuations in the solar wind dynamic pressure were the direct driving mechanisms for the observed boundary oscillations. Instead, the likely mechanism for the localized boundary oscillations was pulsed reconnection at the magnetopause occurring along the X-line extending over the same 4-h region. The Pc5 band pressure fluctuations commonly seen in high-speed solar wind streams may modulate the reconnection rate as an

  12. An Introduction to Intelligent Processing Programs Developed by the Air Force Manufacturing Technology Directorate

    Sampson, Paul G.; Sny, Linda C.

    1992-01-01

    The Air Force has numerous on-going manufacturing and integration development programs (machine tools, composites, metals, assembly, and electronics) which are instrumental in improving productivity in the aerospace industry, but more importantly, have identified strategies and technologies required for the integration of advanced processing equipment. An introduction to four current Air Force Manufacturing Technology Directorate (ManTech) manufacturing areas is provided. Research is being carried out in the following areas: (1) machining initiatives for aerospace subcontractors which provide for advanced technology and innovative manufacturing strategies to increase the capabilities of small shops; (2) innovative approaches to advance machine tool products and manufacturing processes; (3) innovative approaches to advance sensors for process control in machine tools; and (4) efforts currently underway to develop, with the support of industry, the Next Generation Workstation/Machine Controller (Low-End Controller Task).

  13. X-Ray Detection and Processing Models for Spacecraft Navigation and Timing

    Sheikh, Suneel; Hanson, John

    2013-01-01

    The current primary method of deepspace navigation is the NASA Deep Space Network (DSN). High-performance navigation is achieved using Delta Differential One-Way Range techniques that utilize simultaneous observations from multiple DSN sites, and incorporate observations of quasars near the line-of-sight to a spacecraft in order to improve the range and angle measurement accuracies. Over the past four decades, x-ray astronomers have identified a number of xray pulsars with pulsed emissions having stabilities comparable to atomic clocks. The x-ray pulsar-based navigation and time determination (XNAV) system uses phase measurements from these sources to establish autonomously the position of the detector, and thus the spacecraft, relative to a known reference frame, much as the Global Positioning System (GPS) uses phase measurements from radio signals from several satellites to establish the position of the user relative to an Earth-centered fixed frame of reference. While a GPS receiver uses an antenna to detect the radio signals, XNAV uses a detector array to capture the individual xray photons from the x-ray pulsars. The navigation solution relies on detailed xray source models, signal processing, navigation and timing algorithms, and analytical tools that form the basis of an autonomous XNAV system. Through previous XNAV development efforts, some techniques have been established to utilize a pulsar pulse time-of-arrival (TOA) measurement to correct a position estimate. One well-studied approach, based upon Kalman filter methods, optimally adjusts a dynamic orbit propagation solution based upon the offset in measured and predicted pulse TOA. In this delta position estimator scheme, previously estimated values of spacecraft position and velocity are utilized from an onboard orbit propagator. Using these estimated values, the detected arrival times at the spacecraft of pulses from a pulsar are compared to the predicted arrival times defined by the pulsar s pulse

  14. Progress in the development of the reverse osmosis process for spacecraft wash water recovery.

    Pecoraro, J. N.; Podall, H. E.; Spurlock, J. M.

    1972-01-01

    Research work on ambient- and pasteurization-temperature reverse osmosis processes for wash water recovery in a spacecraft environment is reviewed, and the advantages and drawbacks of each are noted. A key requirement in each case is to provide a membrane of appropriate stability and semipermeability. Reverse osmosis systems intended for such use must also take into account the specific limitations and requirements imposed by the small volume of water to be processed and the high water recovery desired. The incorporation of advanced high-temperature membranes into specially designed modules is discussed.

  15. Methodology for the evaluation process in the director´s preparation from education.

    Humberto Clemente Calderón Echevarría

    2014-03-01

    Full Text Available The presented work proposes a methodology oriented to the evaluation of the process of director´s preparation which may contribute to the improvement of the program. It explains the need of the evaluation, activity as such, indicators to evaluate, methods and techniques to be used and the steps in which have to be done. Until now doesn´t exist a methodology which can evaluate the process of directors’ preparation in the educational sector. The development of this methodology has as a background the result obtained by means of different investigations made in the Provincial Post Office and that later were applied in the Provincial Department of Education. Nowadays is perfected in the Pedagogical University "Capitán Silverio Blanco Núñez", thus, the employment opportunities in similar processes of other entities. In the proposed methodology is conceived that the process evaluation of the director’s preparation flows out in a cyclical manner, continuous, flexible, and interactive, away from the traditional linear formula, rigid and schematic. From the above idea it can be identify four stages, and the relevant procedures, the evaluation of the process of directors’ preparation in education.

  16. The Interaction of Spacecraft Cabin Atmospheric Quality and Water Processing System Performance

    Perry, Jay L.; Croomes, Scott D. (Technical Monitor)

    2002-01-01

    Although designed to remove organic contaminants from a variety of waste water streams, the planned U.S.- and present Russian-provided water processing systems onboard the International Space Station (ISS) have capacity limits for some of the more common volatile cleaning solvents used for housekeeping purposes. Using large quantities of volatile cleaning solvents during the ground processing and in-flight operational phases of a crewed spacecraft such as the ISS can lead to significant challenges to the water processing systems. To understand the challenges facing the management of water processing capacity, the relationship between cabin atmospheric quality and humidity condensate loading is presented. This relationship is developed as a tool to determine the cabin atmospheric loading that may compromise water processing system performance. A comparison of cabin atmospheric loading with volatile cleaning solvents from ISS, Mir, and Shuttle are presented to predict acceptable limits to maintain optimal water processing system performance.

  17. Development and qualification of materials and processes for radiation shielding of Galileo spacecraft electronic components

    Hribar, F.; Bauer, J.L.; O'Donnell, T.P.

    1990-01-01

    Several materials and processing methods were evaluated for use on the JPL Galileo spacecraft in the area of radiation shielding for electronics. Development and qualification activities involving an aluminum structural laminate are described. These activities included requirements assessment, design tradeoffs, materials selection, adhesive bonding development, mechanical properties measurements, thermal stability assessment, and nondestructive evaluation. This paper presents evaluation of three adhesives for bonding tantalum to aluminum. The concept of combining a thin sheet of tantalum with two outer aluminum face sheets using adhesive bonding was developed successfully. This radiation shield laminate also provides a structural shear plate for mounting electronic assemblies

  18. Risks and reliability of manufacturing processes as related to composite materials for spacecraft structures

    Bao, Han P.

    1995-01-01

    Fabricating primary aircraft and spacecraft structures using advanced composite materials entail both benefits and risks. The benefits come from much improved strength-to-weight ratios and stiffness-to-weight ratios, potential for less part count, ability to tailor properties, chemical and solvent resistance, and superior thermal properties. On the other hand, the risks involved include high material costs, lack of processing experience, expensive labor, poor reproducibility, high toxicity for some composites, and a variety of space induced risks. The purpose of this project is to generate a manufacturing database for a selected number of materials with potential for space applications, and to rely on this database to develop quantitative approaches to screen candidate materials and processes for space applications on the basis of their manufacturing risks including costs. So far, the following materials have been included in the database: epoxies, polycyanates, bismalemides, PMR-15, polyphenylene sulfides, polyetherimides, polyetheretherketone, and aluminum lithium. The first four materials are thermoset composites; the next three are thermoplastic composites, and the last one is is a metal. The emphasis of this database is on factors affecting manufacturing such as cost of raw material, handling aspects which include working life and shelf life of resins, process temperature, chemical/solvent resistance, moisture resistance, damage tolerance, toxicity, outgassing, thermal cycling, and void content, nature or type of process, associate tooling, and in-process quality assurance. Based on industry experience and published literature, a relative ranking was established for each of the factors affecting manufacturing as listed above. Potential applications of this database include the determination of a delta cost factor for specific structures with a given process plan and a general methodology to screen materials and processes for incorporation into the current

  19. Separation and Purification of Mineral Salts from Spacecraft Wastewater Processing via Electrostatic Beneficiation

    Miles, John D., II; Lunn, Griffin

    2013-01-01

    Electrostatic separation is a class of material processing technologies commonly used for the sorting of coarse mixtures by means of electrical forces acting on charged or polarized particles. Most if not all of the existing tribo-electrostatic separators had been initially developed for mineral ores beneficiation. It is a well-known process that has been successfully used to separate coal from minerals. Potash (potassium) enrichment where underground salt mines containing large amounts of sodium is another use of this techno logy. Through modification this technology can be used for spacecraft wastewater brine beneficiation. This will add in closing the gap beeen traveling around Earth's Gravity well and long-term space explorations. Food has been brought on all man missions, which is why plant growth for food crops continues to be of interest to NASA. For long-term mission considerations food productions is one of the top priorities. Nutrient recovery is essential for surviving in or past low earth orbit. In our advance bio-regenerative process instead of nitrogen gas produced; soluble nitrate salts that can be recovered for plant fertilizer would be produced instead. The only part missing is the beneficiation of brine to separate the potassium from the sodium. The use of electrostatic beneficiation in this experiment utilizes the electrical charge differences between aluminum and dried brine by surface contact. The helixes within the aluminum tribocharger allows for more surface contact when being agitated. When two materials are in contact, the material with the highest affinity for electrons becomes negatively charged, while the other becomes positively charged. This contact exchange of charge may cause the particles to agglomerate depending on their residence time within the tribocharger, compromising the efficiency of separation. The aim of this experiment is to further the development in electrostatic beneficiation by optimizing the separation of ersatz and

  20. Spacecraft Data Simulator for the test of level zero processing systems

    Shi, Jeff; Gordon, Julie; Mirchandani, Chandru; Nguyen, Diem

    1994-01-01

    The Microelectronic Systems Branch (MSB) at Goddard Space Flight Center (GSFC) has developed a Spacecraft Data Simulator (SDS) to support the development, test, and verification of prototype and production Level Zero Processing (LZP) systems. Based on a disk array system, the SDS is capable of generating large test data sets up to 5 Gigabytes and outputting serial test data at rates up to 80 Mbps. The SDS supports data formats including NASA Communication (Nascom) blocks, Consultative Committee for Space Data System (CCSDS) Version 1 & 2 frames and packets, and all the Advanced Orbiting Systems (AOS) services. The capability to simulate both sequential and non-sequential time-ordered downlink data streams with errors and gaps is crucial to test LZP systems. This paper describes the system architecture, hardware and software designs, and test data designs. Examples of test data designs are included to illustrate the application of the SDS.

  1. Design Process of Flight Vehicle Structures for a Common Bulkhead and an MPCV Spacecraft Adapter

    Aggarwal, Pravin; Hull, Patrick V.

    2015-01-01

    Design and manufacturing space flight vehicle structures is a skillset that has grown considerably at NASA during that last several years. Beginning with the Ares program and followed by the Space Launch System (SLS); in-house designs were produced for both the Upper Stage and the SLS Multipurpose crew vehicle (MPCV) spacecraft adapter. Specifically, critical design review (CDR) level analysis and flight production drawing were produced for the above mentioned hardware. In particular, the experience of this in-house design work led to increased manufacturing infrastructure for both Marshal Space Flight Center (MSFC) and Michoud Assembly Facility (MAF), improved skillsets in both analysis and design, and hands on experience in building and testing (MSA) full scale hardware. The hardware design and development processes from initiation to CDR and finally flight; resulted in many challenges and experiences that produced valuable lessons. This paper builds on these experiences of NASA in recent years on designing and fabricating flight hardware and examines the design/development processes used, as well as the challenges and lessons learned, i.e. from the initial design, loads estimation and mass constraints to structural optimization/affordability to release of production drawing to hardware manufacturing. While there are many documented design processes which a design engineer can follow, these unique experiences can offer insight into designing hardware in current program environments and present solutions to many of the challenges experienced by the engineering team.

  2. Pickup ion processes associated with spacecraft thrusters: Implications for solar probe plus

    Clemens, Adam, E-mail: a.j.clemens@qmul.ac.uk; Burgess, David [School of Physics and Astronomy, Queen Mary University of London, London (United Kingdom)

    2016-03-15

    Chemical thrusters are widely used in spacecraft for attitude control and orbital manoeuvres. They create an exhaust plume of neutral gas which produces ions via photoionization and charge exchange. Measurements of local plasma properties will be affected by perturbations caused by the coupling between the newborn ions and the plasma. A model of neutral expansion has been used in conjunction with a fully three-dimensional hybrid code to study the evolution and ionization over time of the neutral cloud produced by the firing of a mono-propellant hydrazine thruster as well as the interactions of the resulting ion cloud with the ambient solar wind. Results are presented which show that the plasma in the region near to the spacecraft will be perturbed for an extended period of time with the formation of an interaction region around the spacecraft, a moderate amplitude density bow wave bounding the interaction region and evidence of an instability at the forefront of the interaction region which causes clumps of ions to be ejected from the main ion cloud quasi-periodically.

  3. Technology for organization of the onboard system for processing and storage of ERS data for ultrasmall spacecraft

    Strotov, Valery V.; Taganov, Alexander I.; Konkin, Yuriy V.; Kolesenkov, Aleksandr N.

    2017-10-01

    Task of processing and analysis of obtained Earth remote sensing data on ultra-small spacecraft board is actual taking into consideration significant expenditures of energy for data transfer and low productivity of computers. Thereby, there is an issue of effective and reliable storage of the general information flow obtained from onboard systems of information collection, including Earth remote sensing data, into a specialized data base. The paper has considered peculiarities of database management system operation with the multilevel memory structure. For storage of data in data base the format has been developed that describes a data base physical structure which contains required parameters for information loading. Such structure allows reducing a memory size occupied by data base because it is not necessary to store values of keys separately. The paper has shown architecture of the relational database management system oriented into embedment into the onboard ultra-small spacecraft software. Data base for storage of different information, including Earth remote sensing data, can be developed by means of such database management system for its following processing. Suggested database management system architecture has low requirements to power of the computer systems and memory resources on the ultra-small spacecraft board. Data integrity is ensured under input and change of the structured information.

  4. Modeling Memory Processes and Performance Benchmarks of AWACS Weapons Director Teams

    2006-01-31

    levels of processing generally lead to higher levels of performance than shallow levels of processing ( Craik & Lockhart ...making. New York: John Wiley & Sons. Craik , F.I.M., & Lockhart , R.S. (1972). Levels of processing : A framework for memory research. Journal of Verbal...representation. The type of processing occurring at encoding has been demonstrated to result in differential levels of memory performance ( Craik

  5. Independent Directors

    Ringe, Wolf-Georg

    2013-01-01

    This paper re-evaluates the corporate governance concept of ‘board independence’ against the disappointing experiences during the 2007-08 financial crisis. Independent or outside directors had long been seen as an essential tool to improve the monitoring role of the board. Yet the crisis revealed...... that they did not prevent firms' excessive risk taking; further, these directors sometimes showed serious deficits in understanding the business they were supposed to control, and remained passive in addressing structural problems. A closer look reveals that under the surface of seemingly unanimous consensus...

  6. Multibody dynamical modeling for spacecraft docking process with spring-damper buffering device: A new validation approach

    Daneshjou, Kamran; Alibakhshi, Reza

    2018-01-01

    In the current manuscript, the process of spacecraft docking, as one of the main risky operations in an on-orbit servicing mission, is modeled based on unconstrained multibody dynamics. The spring-damper buffering device is utilized here in the docking probe-cone system for micro-satellites. Owing to the impact occurs inevitably during docking process and the motion characteristics of multibody systems are remarkably affected by this phenomenon, a continuous contact force model needs to be considered. Spring-damper buffering device, keeping the spacecraft stable in an orbit when impact occurs, connects a base (cylinder) inserted in the chaser satellite and the end of docking probe. Furthermore, by considering a revolute joint equipped with torsional shock absorber, between base and chaser satellite, the docking probe can experience both translational and rotational motions simultaneously. Although spacecraft docking process accompanied by the buffering mechanisms may be modeled by constrained multibody dynamics, this paper deals with a simple and efficient formulation to eliminate the surplus generalized coordinates and solve the impact docking problem based on unconstrained Lagrangian mechanics. By an example problem, first, model verification is accomplished by comparing the computed results with those recently reported in the literature. Second, according to a new alternative validation approach, which is based on constrained multibody problem, the accuracy of presented model can be also evaluated. This proposed verification approach can be applied to indirectly solve the constrained multibody problems by minimum required effort. The time history of impact force, the influence of system flexibility and physical interaction between shock absorber and penetration depth caused by impact are the issues followed in this paper. Third, the MATLAB/SIMULINK multibody dynamic analysis software will be applied to build impact docking model to validate computed results and

  7. Optimal control of stretching process of flexible solar arrays on spacecraft based on a hybrid optimization strategy

    Qijia Yao

    2017-07-01

    Full Text Available The optimal control of multibody spacecraft during the stretching process of solar arrays is investigated, and a hybrid optimization strategy based on Gauss pseudospectral method (GPM and direct shooting method (DSM is presented. First, the elastic deformation of flexible solar arrays was described approximately by the assumed mode method, and a dynamic model was established by the second Lagrangian equation. Then, the nonholonomic motion planning problem is transformed into a nonlinear programming problem by using GPM. By giving fewer LG points, initial values of the state variables and control variables were obtained. A serial optimization framework was adopted to obtain the approximate optimal solution from a feasible solution. Finally, the control variables were discretized at LG points, and the precise optimal control inputs were obtained by DSM. The optimal trajectory of the system can be obtained through numerical integration. Through numerical simulation, the stretching process of solar arrays is stable with no detours, and the control inputs match the various constraints of actual conditions. The results indicate that the method is effective with good robustness. Keywords: Motion planning, Multibody spacecraft, Optimal control, Gauss pseudospectral method, Direct shooting method

  8. Director Networks and Takeovers

    Renneboog, L.D.R.; Zhao, Y.

    2013-01-01

    Abstract: We study the impact of corporate networks on the takeover process. We find that better connected companies are more active bidders. When a bidder and a target have one or more directors in common, the probability that the takeover transaction will be successfully completed augments, and

  9. Director networks and takeovers

    Renneboog, L.D.R.; Zhao, Y.

    2014-01-01

    We study the impact of corporate networks on the takeover process. We find that better connected companies are more active bidders. When a bidder and a target have one or more directors in common, the probability that the takeover transaction will be successfully completed augments, and the duration

  10. Defining and Selecting Independent Directors

    Eric Pichet

    2017-10-01

    Full Text Available Drawing from the Enlightened Shareholder Theory that the author first developed in 2011, this theoretical paper with practical and normative ambitions achieves a better definition of independent director, while improving the understanding of the roles he fulfils on boards of directors. The first part defines constructs like firms, Governance system and Corporate governance, offering a clear distinction between the latter two concepts before explaining the four main missions of a board. The second part defines the ideal independent director by outlining the objective qualities that are necessary and adding those subjective aspects that have turned this into a veritable profession. The third part defines the ideal process for selecting independent directors, based on nominating committees that should themselves be independent. It also includes ways of assessing directors who are currently in function, as well as modalities for renewing their mandates. The paper’s conclusion presents the Paradox of the Independent Director.

  11. Development of an advanced spacecraft water and waste materials processing system

    Murray, R. W.; Schelkopf, J. D.; Middleton, R. L.

    1975-01-01

    An Integrated Waste Management-Water System (WM-WS) which uses radioisotopes for thermal energy is described and results of its trial in a 4-man, 180 day simulated space mission are presented. It collects urine, feces, trash, and wash water in zero gravity, processes the wastes to a common evaporator, distills and catalytically purifies the water, and separates and incinerates the solid residues using little oxygen and no chemical additives or expendable filters. Technical details on all subsystems are given along with performance specifications. Data on recovered water and heat loss obtained in test trials are presented. The closed loop incinerator and other projects underway to increase system efficiency and capacity are discussed.

  12. Director's report.

    Pathak, K B

    1993-07-01

    The director's report for the International Institute for Population Sciences in Bombay, India, provides descriptions of the Institute's teaching programs, research, publications, seminars, library collection, visitors, faculty and staff, and special events. The teaching programs include regular instruction in one-year diploma courses in population studies and a masters and a masters in philosophy in population studies; a diploma is also available in health education. Student represent a variety of countries for the diploma programs, while the other certificate programs draw on the national population. A listing is provided of those receiving certificates. Research programs are listed by whether the program was completed during 1992-93 or earlier or is a new project. The Institute conducts a National Family Welfare Survey among 23 states. This household survey is directed to women and supplies village level data. The Institute publishes a quarterly newsletter about ongoing activities and a biennial compendium of research findings. The Institute observes World Population Day and organized the 10th Annual Convention on Medical Statistics and other conferences. The Institute held the first meeting of the National Council of Population Research on September 21, 1992, and the designated subcommittee members met on November 14, 1992. The library recently added 1117 volumes, which contributed to the total library collection of 55,539 volumes, including 8000 bound periodicals and 12,615 reprints. Several high government officials visited the Institute in 1992. Other visitors came from the US, Bangladesh, and the UN. The Institute is comprised of six academic departments with computer and library resources. Staff were involved a few overseas tours of study. Founders day is celebrated as a cultural event.

  13. Advertising and algorithms – the obvious gains and hidden losses of using software with intelligent agent capabilities in the creative process of art directors and copywriters

    Barker, Richie

    2017-01-01

    Situated at the intersection of information technology, advertising and creativity theory, this thesis presents a detailed picture of the influence of autonomous software applications on the creative process of advertising art directors and copywriters. These applications, which are known in the field of information technology as ‘intelligent agents,’ commonly possess the ability to learn from the user and autonomously pursue their own goals. The search engine Google, which employs intelligen...

  14. Integration of Leadership Styles of School Director

    Pavlovic, Nebojsa; Oljaca, Milka; Kostovic, Svetlana

    2012-01-01

    Management style can be defined as a special behavior of directors in the work process that affects the performance in an organization, in this case-school. Management style has two related meanings: first is behavior of directors to employees, second is directors' approach in school regarding management, participation of employees in decision…

  15. Modeling Temporal Processes in Early Spacecraft Design: Application of Discrete-Event Simulations for Darpa's F6 Program

    Dubos, Gregory F.; Cornford, Steven

    2012-01-01

    While the ability to model the state of a space system over time is essential during spacecraft operations, the use of time-based simulations remains rare in preliminary design. The absence of the time dimension in most traditional early design tools can however become a hurdle when designing complex systems whose development and operations can be disrupted by various events, such as delays or failures. As the value delivered by a space system is highly affected by such events, exploring the trade space for designs that yield the maximum value calls for the explicit modeling of time.This paper discusses the use of discrete-event models to simulate spacecraft development schedule as well as operational scenarios and on-orbit resources in the presence of uncertainty. It illustrates how such simulations can be utilized to support trade studies, through the example of a tool developed for DARPA's F6 program to assist the design of "fractionated spacecraft".

  16. Spacecraft operations

    Sellmaier, Florian; Schmidhuber, Michael

    2015-01-01

    The book describes the basic concepts of spaceflight operations, for both, human and unmanned missions. The basic subsystems of a space vehicle are explained in dedicated chapters, the relationship of spacecraft design and the very unique space environment are laid out. Flight dynamics are taught as well as ground segment requirements. Mission operations are divided into preparation including management aspects, execution and planning. Deep space missions and space robotic operations are included as special cases. The book is based on a course held at the German Space Operation Center (GSOC).

  17. Mechanical Design of Spacecraft

    1962-01-01

    In the spring of 1962, engineers from the Engineering Mechanics Division of the Jet Propulsion Laboratory gave a series of lectures on spacecraft design at the Engineering Design seminars conducted at the California Institute of Technology. Several of these lectures were subsequently given at Stanford University as part of the Space Technology seminar series sponsored by the Department of Aeronautics and Astronautics. Presented here are notes taken from these lectures. The lectures were conceived with the intent of providing the audience with a glimpse of the activities of a few mechanical engineers who are involved in designing, building, and testing spacecraft. Engineering courses generally consist of heavily idealized problems in order to allow the more efficient teaching of mathematical technique. Students, therefore, receive a somewhat limited exposure to actual engineering problems, which are typified by more unknowns than equations. For this reason it was considered valuable to demonstrate some of the problems faced by spacecraft designers, the processes used to arrive at solutions, and the interactions between the engineer and the remainder of the organization in which he is constrained to operate. These lecture notes are not so much a compilation of sophisticated techniques of analysis as they are a collection of examples of spacecraft hardware and associated problems. They will be of interest not so much to the experienced spacecraft designer as to those who wonder what part the mechanical engineer plays in an effort such as the exploration of space.

  18. Spacecraft Attitude Determination

    Bak, Thomas

    This thesis describes the development of an attitude determination system for spacecraft based only on magnetic field measurements. The need for such system is motivated by the increased demands for inexpensive, lightweight solutions for small spacecraft. These spacecraft demands full attitude...... determination based on simple, reliable sensors. Meeting these objectives with a single vector magnetometer is difficult and requires temporal fusion of data in order to avoid local observability problems. In order to guaranteed globally nonsingular solutions, quaternions are generally the preferred attitude...... is a detailed study of the influence of approximations in the modeling of the system. The quantitative effects of errors in the process and noise statistics are discussed in detail. The third contribution is the introduction of these methods to the attitude determination on-board the Ørsted satellite...

  19. Case Studies in Crewed Spacecraft Environmental Control and Life Support System Process Compatibility and Cabin Environmental Impact

    Perry, J. L.

    2017-01-01

    Contamination of a crewed spacecraft's cabin environment leading to environmental control and life support system (ECLSS) functional capability and operational margin degradation or loss can have an adverse effect on NASA's space exploration mission figures of merit-safety, mission success, effectiveness, and affordability. The role of evaluating the ECLSS's compatibility and cabin environmental impact as a key component of pass trace contaminant control is presented and the technical approach is described in the context of implementing NASA's safety and mission success objectives. Assessment examples are presented for a variety of chemicals used in vehicle systems and experiment hardware for the International Space Station program. The ECLSS compatibility and cabin environmental impact assessment approach, which can be applied to any crewed spacecraft development and operational effort, can provide guidance to crewed spacecraft system and payload developers relative to design criteria assigned ECLSS compatibility and cabin environmental impact ratings can be used by payload and system developers as criteria for ensuring adequate physical and operational containment. In additional to serving as an aid for guiding containment design, the assessments can guide flight rule and procedure development toward protecting the ECLSS as well as approaches for contamination event remediation.

  20. Spacecraft radiator systems

    Anderson, Grant A. (Inventor)

    2012-01-01

    A spacecraft radiator system designed to provide structural support to the spacecraft. Structural support is provided by the geometric "crescent" form of the panels of the spacecraft radiator. This integration of radiator and structural support provides spacecraft with a semi-monocoque design.

  1. Director`s series on proliferation

    Bailey, K.C.; Price, M.E. [eds.

    1994-12-27

    The Director`s Series on Proliferation is an occasional publication of essays on the topics of nuclear, chemical, biological, and missile proliferation. The seven papers presented in this issue cover the following topics: Should the Treaty on the Nonproliferation of Nuclear Weapons (NPT) be amended?; NPT extension - Legal and procedural issues; An Indonesian view of NPT review conference issues; The treaty of Tlatelolco and the NPT - Tools for peace and development; Perspectives on cut-off, weapons dismantlement, and security assurances; Belarus and NPT challenges; A perspective on the chemical weapons convention - Lessons learned from the preparatory commission.

  2. ICU Director Data

    Ogbu, Ogbonna C.; Coopersmith, Craig M.

    2015-01-01

    Improving value within critical care remains a priority because it represents a significant portion of health-care spending, faces high rates of adverse events, and inconsistently delivers evidence-based practices. ICU directors are increasingly required to understand all aspects of the value provided by their units to inform local improvement efforts and relate effectively to external parties. A clear understanding of the overall process of measuring quality and value as well as the strengths, limitations, and potential application of individual metrics is critical to supporting this charge. In this review, we provide a conceptual framework for understanding value metrics, describe an approach to developing a value measurement program, and summarize common metrics to characterize ICU value. We first summarize how ICU value can be represented as a function of outcomes and costs. We expand this equation and relate it to both the classic structure-process-outcome framework for quality assessment and the Institute of Medicine’s six aims of health care. We then describe how ICU leaders can develop their own value measurement process by identifying target areas, selecting appropriate measures, acquiring the necessary data, analyzing the data, and disseminating the findings. Within this measurement process, we summarize common metrics that can be used to characterize ICU value. As health care, in general, and critical care, in particular, changes and data become more available, it is increasingly important for ICU leaders to understand how to effectively acquire, evaluate, and apply data to improve the value of care provided to patients. PMID:25846533

  3. Worldwide Spacecraft Crew Hatch History

    Johnson, Gary

    2009-01-01

    The JSC Flight Safety Office has developed this compilation of historical information on spacecraft crew hatches to assist the Safety Tech Authority in the evaluation and analysis of worldwide spacecraft crew hatch design and performance. The document is prepared by SAIC s Gary Johnson, former NASA JSC S&MA Associate Director for Technical. Mr. Johnson s previous experience brings expert knowledge to assess the relevancy of data presented. He has experience with six (6) of the NASA spacecraft programs that are covered in this document: Apollo; Skylab; Apollo Soyuz Test Project (ASTP), Space Shuttle, ISS and the Shuttle/Mir Program. Mr. Johnson is also intimately familiar with the JSC Design and Procedures Standard, JPR 8080.5, having been one of its original developers. The observations and findings are presented first by country and organized within each country section by program in chronological order of emergence. A host of reference sources used to augment the personal observations and comments of the author are named within the text and/or listed in the reference section of this document. Careful attention to the selection and inclusion of photos, drawings and diagrams is used to give visual association and clarity to the topic areas examined.

  4. Administrative behavior of directors in hospitals: the Israeli case.

    Stern, Z; Schmid, H; Nirel, N

    1994-01-01

    This article presents research findings on the behavior of directors in hospitals in Israel. According to the findings, hospital directors devote most of their time to internal organization processes and less time to the management of the external organizational environment. The findings also reveal that the orientation of these directors is toward centralization of authority and concentration of the decision-making process.

  5. Case Management Directors

    Bankston White, Cheri; Birmingham, Jackie

    2015-01-01

    Purpose and Objectives: Case management directors are in a dynamic position to affect the transition of care of patients across the continuum, work with all levels of providers, and support the financial well-being of a hospital. Most importantly, they can drive good patient outcomes. Although the position is critical on many different levels, there is little to help guide a new director in attending to all the “moving parts” of such a complex role. This is Part 2 of a two-part article written for case management directors, particularly new ones. Part 1 covered the first 4 of 7 tracks: (1) Staffing and Human Resources, (2) Compliance and Accreditation, (3) Discharge Planning and (4) Utilization Review and Revenue Cycle. Part 2 addresses (5) Internal Departmental Relationships (Organizational), (6) External Relationships (Community Agency), and (7) Quality and Program Outcomes. This article attempts to answer the following questions: Are case management directors prepared for an expanded role that affects departments and organizations outside of their own?How does a case management director manage the transition of care of patients while managing required relationships outside the department?How does the director manage program outcomes in such a complex department? Primary Practice Setting: The information is most meaningful to those case management directors who work in either stand-alone hospitals or integrated health systems and have frontline case managers (CMs) reporting to them. Findings/Conclusions: Part 1 found that case management directors would benefit from further research and documentation of “best practices” related to their role, particularly in the areas of leadership and management. The same conclusion applies to Part 2, which addresses the director's responsibilities outside her immediate department. Leadership and management skills apply as well to building strong, productive relationships across a broad spectrum of external organizations

  6. Ulysses spacecraft control and monitoring system

    Hamer, P. A.; Snowden, P. J.

    1991-01-01

    The baseline Ulysses spacecraft control and monitoring system (SCMS) concepts and the converted SCMS, residing on a DEC/VAX 8350 hardware, are considered. The main functions of the system include monitoring and displaying spacecraft telemetry, preparing spacecraft commands, producing hard copies of experimental data, and archiving spacecraft telemetry. The SCMS system comprises over 20 subsystems ranging from low-level utility routines to the major monitoring and control software. These in total consist of approximately 55,000 lines of FORTRAN source code and 100 VMS command files. The SCMS major software facilities are described, including database files, telemetry processing, telecommanding, archiving of data, and display of telemetry.

  7. Identifying influential directors in the United States corporate governance network

    Huang, Xuqing; Vodenska, Irena; Wang, Fengzhong; Havlin, Shlomo; Stanley, H. Eugene

    2011-10-01

    The influence of directors has been one of the most engaging topics recently, but surprisingly little research has been done to quantitatively evaluate the influence and power of directors. We analyze the structure of the US corporate governance network for the 11-year period 1996-2006 based on director data from the Investor Responsibility Research Center director database, and we develop a centrality measure named the influence factor to estimate the influence of directors quantitatively. The US corporate governance network is a network of directors with nodes representing directors and links between two directors representing their service on common company boards. We assume that information flows in the network through information-sharing processes among linked directors. The influence factor assigned to a director is based on the level of information that a director obtains from the entire network. We find that, contrary to commonly accepted belief that directors of large companies, measured by market capitalization, are the most powerful, in some instances, the directors who are influential do not necessarily serve on boards of large companies. By applying our influence factor method to identify the influential people contained in the lists created by popular magazines such as Fortune, Networking World, and Treasury and Risk Management, we find that the influence factor method is consistently either the best or one of the two best methods in identifying powerful people compared to other general centrality measures that are used to denote the significance of a node in complex network theory.

  8. Identifying influential directors in the United States corporate governance network.

    Huang, Xuqing; Vodenska, Irena; Wang, Fengzhong; Havlin, Shlomo; Stanley, H Eugene

    2011-10-01

    The influence of directors has been one of the most engaging topics recently, but surprisingly little research has been done to quantitatively evaluate the influence and power of directors. We analyze the structure of the US corporate governance network for the 11-year period 1996-2006 based on director data from the Investor Responsibility Research Center director database, and we develop a centrality measure named the influence factor to estimate the influence of directors quantitatively. The US corporate governance network is a network of directors with nodes representing directors and links between two directors representing their service on common company boards. We assume that information flows in the network through information-sharing processes among linked directors. The influence factor assigned to a director is based on the level of information that a director obtains from the entire network. We find that, contrary to commonly accepted belief that directors of large companies, measured by market capitalization, are the most powerful, in some instances, the directors who are influential do not necessarily serve on boards of large companies. By applying our influence factor method to identify the influential people contained in the lists created by popular magazines such as Fortune, Networking World, and Treasury and Risk Management, we find that the influence factor method is consistently either the best or one of the two best methods in identifying powerful people compared to other general centrality measures that are used to denote the significance of a node in complex network theory.

  9. Spacecraft Spin Test Facility

    Federal Laboratory Consortium — FUNCTION: Provides the capability to correct unbalances of spacecraft by using dynamic measurement techniques and static/coupled measurements to provide products of...

  10. Spacecraft command and control using expert systems

    Norcross, Scott; Grieser, William H.

    1994-01-01

    This paper describes a product called the Intelligent Mission Toolkit (IMT), which was created to meet the changing demands of the spacecraft command and control market. IMT is a command and control system built upon an expert system. Its primary functions are to send commands to the spacecraft and process telemetry data received from the spacecraft. It also controls the ground equipment used to support the system, such as encryption gear, and telemetry front-end equipment. Add-on modules allow IMT to control antennas and antenna interface equipment. The design philosophy for IMT is to utilize available commercial products wherever possible. IMT utilizes Gensym's G2 Real-time Expert System as the core of the system. G2 is responsible for overall system control, spacecraft commanding control, and spacecraft telemetry analysis and display. Other commercial products incorporated into IMT include the SYBASE relational database management system and Loral Test and Integration Systems' System 500 for telemetry front-end processing.

  11. Culham names new director

    2003-01-01

    "The United Kingdom Atomic Energy Authority (UKAEA) announced the appointment of Professor Sir Chris Llewellyn Smith FRS (Fellow of the Royal Society) as Director of Culham, responsible for developing and implementing the strategy for the UK's fusion research programme" (1 page).

  12. Ideas for Directors.

    Child Care Information Exchange, 1987

    1987-01-01

    Presents child care center directors with a variety of relevant management ideas from business and the child care field. They include translating employee body language; leadership myths; on-the-job teacher training; undesirable bosses; wasting employee talent; voicing disagreement; employee anger; encouraging creativity; and coping with late…

  13. REGIONAL CUSTOMS DIRECTORATES MANAGEMENT

    CABA STEFAN

    2009-05-01

    Full Text Available The management of a regional customs directorate is analyzed. A new approach of the managerial system, in the European integration context, is presented. The customs system is one of the first “doors” to a new economic, social and cultural community. For

  14. Director, Platform and Audience.

    Meyer, Richard D.

    The open stage is discussed both as architecture and as part of a new theatrical style. In reference to use of the open stage, emphasis is given to specifics with which the director must deal, to special problems of the actor, to the approach to blocking a play, and to the open stage as "theatrical experience". The architectural advantage of the…

  15. Spacecraft Charge Monitor

    Goembel, L.

    2003-12-01

    We are currently developing a flight prototype Spacecraft Charge Monitor (SCM) with support from NASA's Small Business Innovation Research (SBIR) program. The device will use a recently proposed high energy-resolution electron spectroscopic technique to determine spacecraft floating potential. The inspiration for the technique came from data collected by the Atmosphere Explorer (AE) satellites in the 1970s. The data available from the AE satellites indicate that the SCM may be able to determine spacecraft floating potential to within 0.1 V under certain conditions. Such accurate measurement of spacecraft charge could be used to correct biases in space plasma measurements. The device may also be able to measure spacecraft floating potential in the solar wind and in orbit around other planets.

  16. Papike appointed Director of IOM

    James Papike was appointed director of the Institute of Meteoritics in the Department of Geology and Presidential Professor at the University of New Mexico, Albuquerque, on July 1, 1990. Papike succeeded Klaus Keil, who moved to the University of Hawaii to direct the Planetary Geoscience Division at the Hawaii Institute of Geosciences.The newly constituted IOM will emphasize planetary volcanic processes through the study of achondritic meteorites, the Moon, and Earth, and the origin of primitive solar system materials and planetary formation through the study of chondritic meteorites.

  17. Message from Fermilab Director

    2009-01-01

    With this issue’s message, Fermilab Director Pier Oddone opens a new series of occasional exchanges between CERN and other laboratories world-wide. As part of this exchange, CERN Director-General Rolf Heuer, wrote a message in Tuesday’s edition of Fermilab TodayPerspectivesNothing is more important for our worldwide particle physics community than successfully turning on the LHC later this year. The promise for great discoveries is huge, and many of the plans for our future depend on LHC results. Those of us planning national programmes in anticipation of data from the LHC face formidable challenges to develop future facilities that are complementary to the LHC, whatever the physics discoveries may be. At Fermilab, this has led us to move forcefully with a programme at the intensity frontier, where experiments with neutrinos and rare decays open a complementary window into nature. Our ultimate goal for a unified picture of nat...

  18. Beam director design report

    Younger, F.C.

    1986-08-01

    A design and fabrication effort for a beam director is documented. The conceptual design provides for the beam to pass first through a bending and focusing system (or ''achromat''), through a second achromat, through an air-to-vacuum interface (the ''beam window''), and finally through the vernier steering system. Following an initial concept study for a beam director, a prototype permanent magnet 30 0 beam-bending achromat and prototype vernier steering magnet were designed and built. In volume II, copies are included of the funding instruments, requests for quotations, purchase orders, a complete set of as-built drawings, magnetic measurement reports, the concept design report, and the final report on the design and fabrication project

  19. Discussion with CERN Directorate

    CERN. Geneva

    2017-01-01

    Please note that the Discussion with CERN Directorate will be transmitted also in the following rooms: Council Chamber - 503-1-001 IT Amphitheatre - 31-3-004 Prevessin 774-R-013 Simultaneous interpreting into French and English will be available in the Main Auditorium. Une interprétation simultanée en français et en anglais sera disponible dans l'amphithéâtre principal.

  20. Lands directorate publications

    1981-01-01

    The directorate has a lead role in providing advice to the federal government on land use policy in Canada. The Canada Land Inventory (CLI) Program has produced significant amounts of data pertaining to the capability of Canadian lands to support agriculture, forestry, recreation, wildlife and sport fish. A list of CLI reports is presented in this publication. In addition, and capability maps have been compiled for agricultural, forestry, recreation and wildlife and are listed and described in this publication. (KRM)

  1. End-to-end process of hollow spacecraft structures with high frequency and low mass obtained with in-house structural optimization tool and additive manufacturing

    Alexandru-Mihai CISMILIANU

    2017-09-01

    Full Text Available In the space sector the most decisive elements are: mass reduction, cost saving and minimum lead time; here, structural optimization and additive layer manufacturing (ALM fit best. The design must be driven by stiffness, because an important requirement for spacecraft (S/C structures is to reduce the dynamic coupling between the S/C and the launch vehicle. The objective is to create an end-to-end process, from the input given by the customer to the manufacturing of an aluminum part as light as possible but at the same time considerably stiffer while taking the full advantage of the design flexibility given by ALM. To design and optimize the parts, a specialized in-house tool was used, guaranteeing a load-sufficient material distribution. Using topological optimization, the iterations between the design and the stress departments were diminished, thus greatly reducing the lead time. In order to improve and lighten the obtained structure a design with internal cavities and hollow beams was considered. This implied developing of a procedure for powder evacuation through iterations with the manufacturer while optimizing the design for ALM. The resulted part can be then manufactured via ALM with no need of further design adjustments. To achieve a high-quality part with maximum efficiency, it is essential to have a loop between the design team and the manufacturer. Topological optimization and ALM work hand in hand if used properly. The team achieved a more efficient structure using topology optimization and ALM, than using conventional design and manufacturing methods.

  2. Autonomous spacecraft rendezvous and docking

    Tietz, J. C.; Almand, B. J.

    A storyboard display is presented which summarizes work done recently in design and simulation of autonomous video rendezvous and docking systems for spacecraft. This display includes: photographs of the simulation hardware, plots of chase vehicle trajectories from simulations, pictures of the docking aid including image processing interpretations, and drawings of the control system strategy. Viewgraph-style sheets on the display bulletin board summarize the simulation objectives, benefits, special considerations, approach, and results.

  3. Fractionated Spacecraft Architectures Seeding Study

    Mathieu, Charlotte; Weigel, Annalisa

    2006-01-01

    .... Models were developed from a customer-centric perspective to assess different fractionated spacecraft architectures relative to traditional spacecraft architectures using multi-attribute analysis...

  4. Spacecraft momentum control systems

    Leve, Frederick A; Peck, Mason A

    2015-01-01

    The goal of this book is to serve both as a practical technical reference and a resource for gaining a fuller understanding of the state of the art of spacecraft momentum control systems, specifically looking at control moment gyroscopes (CMGs). As a result, the subject matter includes theory, technology, and systems engineering. The authors combine material on system-level architecture of spacecraft that feature momentum-control systems with material about the momentum-control hardware and software. This also encompasses material on the theoretical and algorithmic approaches to the control of space vehicles with CMGs. In essence, CMGs are the attitude-control actuators that make contemporary highly agile spacecraft possible. The rise of commercial Earth imaging, the advances in privately built spacecraft (including small satellites), and the growing popularity of the subject matter in academic circles over the past decade argues that now is the time for an in-depth treatment of the topic. CMGs are augmented ...

  5. Spacecraft Material Outgassing Data

    National Aeronautics and Space Administration — This compilation of outgassing data of materials intended for spacecraft use were obtained at the Goddard Space Flight Center (GSFC), utilizing equipment developed...

  6. Spacecraft Fire Safety Demonstration

    National Aeronautics and Space Administration — The objective of the Spacecraft Fire Safety Demonstration project is to develop and conduct large-scale fire safety experiments on an International Space Station...

  7. Quick spacecraft charging primer

    Larsen, Brian Arthur

    2014-01-01

    This is a presentation in PDF format which is a quick spacecraft charging primer, meant to be used for program training. It goes into detail about charging physics, RBSP examples, and how to identify charging.

  8. Deployable Brake for Spacecraft

    Rausch, J. R.; Maloney, J. W.

    1987-01-01

    Aerodynamic shield that could be opened and closed proposed. Report presents concepts for deployable aerodynamic brake. Brake used by spacecraft returning from high orbit to low orbit around Earth. Spacecraft makes grazing passes through atmosphere to slow down by drag of brake. Brake flexible shield made of woven metal or ceramic withstanding high temperatures created by air friction. Stored until needed, then deployed by set of struts.

  9. Directors General appointed

    1975-01-01

    At a special session on 21 March, presided over by P. Levaux, the Council of the European Organization for Nuclear Research appointed J . B. Adams and L . Van Hove as Directors General of the Organization for a period of five years beginning 1 January 1976. Dr. Adams will be responsible for the administration of CERN, for the operation of the equipment and services and for the construction of buildings and major equipment. Professor Van Hove will be responsible for the research activities of the Organization.

  10. Internet Technology on Spacecraft

    Rash, James; Parise, Ron; Hogie, Keith; Criscuolo, Ed; Langston, Jim; Powers, Edward I. (Technical Monitor)

    2000-01-01

    The Operating Missions as Nodes on the Internet (OMNI) project has shown that Internet technology works in space missions through a demonstration using the UoSAT-12 spacecraft. An Internet Protocol (IP) stack was installed on the orbiting UoSAT-12 spacecraft and tests were run to demonstrate Internet connectivity and measure performance. This also forms the basis for demonstrating subsequent scenarios. This approach provides capabilities heretofore either too expensive or simply not feasible such as reconfiguration on orbit. The OMNI project recognized the need to reduce the risk perceived by mission managers and did this with a multi-phase strategy. In the initial phase, the concepts were implemented in a prototype system that includes space similar components communicating over the TDRS (space network) and the terrestrial Internet. The demonstration system includes a simulated spacecraft with sample instruments. Over 25 demonstrations have been given to mission and project managers, National Aeronautics and Space Administration (NASA), Department of Defense (DoD), contractor technologists and other decisions makers, This initial phase reached a high point with an OMNI demonstration given from a booth at the Johnson Space Center (JSC) Inspection Day 99 exhibition. The proof to mission managers is provided during this second phase with year 2000 accomplishments: testing the use of Internet technologies onboard an actual spacecraft. This was done with a series of tests performed using the UoSAT-12 spacecraft. This spacecraft was reconfigured on orbit at very low cost. The total period between concept and the first tests was only 6 months! On board software was modified to add an IP stack to support basic IP communications. Also added was support for ping, traceroute and network timing protocol (NTP) tests. These tests show that basic Internet functionality can be used onboard spacecraft. The performance of data was measured to show no degradation from current

  11. Contemporary state of spacecraft/environment interaction research

    Novikov, L S

    1999-01-01

    Various space environment effects on spacecraft materials and equipment, and the reverse effects of spacecrafts and rockets on space environment are considered. The necessity of permanent updating and perfection of our knowledge on spacecraft/environment interaction processes is noted. Requirements imposed on models of space environment in theoretical and experimental researches of various aspects of the spacecraft/environment interaction problem are formulated. In this field, main problems which need to be solved today and in the nearest future are specified. The conclusion is made that the joint analysis of both aspects of spacecraft/environment interaction problem promotes the most effective solution of the problem.

  12. Magnetic heat pump flow director

    Howard, Frank S. (Inventor)

    1995-01-01

    A fluid flow director is disclosed. The director comprises a handle body and combed-teeth extending from one side of the body. The body can be formed of a clear plastic such as acrylic. The director can be used with heat exchangers such as a magnetic heat pump and can minimize the undesired mixing of fluid flows. The types of heat exchangers can encompass both heat pumps and refrigerators. The director can adjust the fluid flow of liquid or gas along desired flow directions. A method of applying the flow director within a magnetic heat pump application is also disclosed where the comb-teeth portions of the director are inserted into the fluid flow paths of the heat pump.

  13. The program director and accreditation

    Tristan, T.A.; Capp, M.P.; Krabbenhoft, K.L.; Armbruster, J.S.

    1987-01-01

    Field Survey is contrasted with the Specialist Site Visitor. The discussion addresses the reasons for different types of surveys and how the surveys and the Hospital Information Form are used in evaluating a graduate residency program in radiology for accreditation. The Residency Review Committee for Radiology (RRC) and the staff of the Accreditation Council for Graduate Medical Education (ACGME) of Residencies in Radiology offer a program for program directors and other interested leaders in graduate programs in radiology. The authors explain the review and accreditation process for residencies in radiology with special emphasis on the preparation for inspection by accurate and full completion of the Hospital Information Form on which the program is judged, and the nature of the inspection procedures

  14. Revamping Spacecraft Operational Intelligence

    Hwang, Victor

    2012-01-01

    The EPOXI flight mission has been testing a new commercial system, Splunk, which employs data mining techniques to organize and present spacecraft telemetry data in a high-level manner. By abstracting away data-source specific details, Splunk unifies arbitrary data formats into one uniform system. This not only reduces the time and effort for retrieving relevant data, but it also increases operational visibility by allowing a spacecraft team to correlate data across many different sources. Splunk's scalable architecture coupled with its graphing modules also provide a solid toolset for generating data visualizations and building real-time applications such as browser-based telemetry displays.

  15. Dips spacecraft integration issues

    Determan, W.R.; Harty, R.B.

    1988-01-01

    The Department of Energy, in cooperation with the Department of Defense, has recently initiated the dynamic isotope power system (DIPS) demonstration program. DIPS is designed to provide 1 to 10 kW of electrical power for future military spacecraft. One of the near-term missions considered as a potential application for DIPS was the boost surveillance and tracking system (BSTS). A brief review and summary of the reasons behind a selection of DIPS for BSTS-type missions is presented. Many of these are directly related to spacecraft integration issues; these issues will be reviewed in the areas of system safety, operations, survivability, reliability, and autonomy

  16. Results of the Association of Directors of Radiation Oncology Programs (ADROP) Survey of Radiation Oncology Residency Program Directors

    Harris, Eleanor; Abdel-Wahab, May; Spangler, Ann E.; Lawton, Colleen A.; Amdur, Robert J.

    2009-01-01

    Purpose: To survey the radiation oncology residency program directors on the topics of departmental and institutional support systems, residency program structure, Accreditation Council for Graduate Medical Education (ACGME) requirements, and challenges as program director. Methods: A survey was developed and distributed by the leadership of the Association of Directors of Radiation Oncology Programs to all radiation oncology program directors. Summary statistics, medians, and ranges were collated from responses. Results: Radiation oncology program directors had implemented all current required aspects of the ACGME Outcome Project into their training curriculum. Didactic curricula were similar across programs nationally, but research requirements and resources varied widely. Program directors responded that implementation of the ACGME Outcome Project and the external review process were among their greatest challenges. Protected time was the top priority for program directors. Conclusions: The Association of Directors of Radiation Oncology Programs recommends that all radiation oncology program directors have protected time and an administrative stipend to support their important administrative and educational role. Departments and institutions should provide adequate and equitable resources to the program directors and residents to meet increasingly demanding training program requirements.

  17. Industry perspectives on Plug-& -Play Spacecraft Avionics

    Franck, R.; Graven, P.; Liptak, L.

    This paper describes the methodologies and findings from an industry survey of awareness and utility of Spacecraft Plug-& -Play Avionics (SPA). The survey was conducted via interviews, in-person and teleconference, with spacecraft prime contractors and suppliers. It focuses primarily on AFRL's SPA technology development activities but also explores the broader applicability and utility of Plug-& -Play (PnP) architectures for spacecraft. Interviews include large and small suppliers as well as large and small spacecraft prime contractors. Through these “ product marketing” interviews, awareness and attitudes can be assessed, key technical and market barriers can be identified, and opportunities for improvement can be uncovered. Although this effort focuses on a high-level assessment, similar processes can be used to develop business cases and economic models which may be necessary to support investment decisions.

  18. Director ownership, outside directors and commitment to corporate social responsibility

    Chen Ying

    2011-01-01

    Full Text Available This paper examines the effects of director ownership and the proportion of outside directors on firms’ commitment to corporate social responsibility (CSR. Using a sample of 453 Hong Kong listed companies for 2005, we find that there is a non-linear relationship between the level of director ownership and firms’ engagement in CSR behavior. Commitment to CSR first increases as the proportion of director ownership increases up to 50% and then decreases as that proportion of ownership grows higher. Further, the proportion of outside directors on the board exhibits a positive relationship with the level of CSR commitment. These results provide explanations for firms’ commitment to CSR from the corporate governance perspective.

  19. SHARP - Automated monitoring of spacecraft health and status

    Atkinson, David J.; James, Mark L.; Martin, R. G.

    1990-01-01

    Briefly discussed here are the spacecraft and ground systems monitoring process at the Jet Propulsion Laboratory (JPL). Some of the difficulties associated with the existing technology used in mission operations are highlighted. A new automated system based on artificial intelligence technology is described which seeks to overcome many of these limitations. The system, called the Spacecraft Health Automated Reasoning Prototype (SHARP), is designed to automate health and status analysis for multi-mission spacecraft and ground data systems operations. The system has proved to be effective for detecting and analyzing potential spacecraft and ground systems problems by performing real-time analysis of spacecraft and ground data systems engineering telemetry. Telecommunications link analysis of the Voyager 2 spacecraft was the initial focus for evaluation of the system in real-time operations during the Voyager spacecraft encounter with Neptune in August 1989.

  20. SHARP: Automated monitoring of spacecraft health and status

    Atkinson, David J.; James, Mark L.; Martin, R. Gaius

    1991-01-01

    Briefly discussed here are the spacecraft and ground systems monitoring process at the Jet Propulsion Laboratory (JPL). Some of the difficulties associated with the existing technology used in mission operations are highlighted. A new automated system based on artificial intelligence technology is described which seeks to overcome many of these limitations. The system, called the Spacecraft Health Automated Reasoning Prototype (SHARP), is designed to automate health and status analysis for multi-mission spacecraft and ground data systems operations. The system has proved to be effective for detecting and analyzing potential spacecraft and ground systems problems by performing real-time analysis of spacecraft and ground data systems engineering telemetry. Telecommunications link analysis of the Voyager 2 spacecraft was the initial focus for evaluation of the system in real-time operations during the Voyager spacecraft encounter with Neptune in August 1989.

  1. 30-kW SEP Spacecraft as Secondary Payloads for Low-Cost Deep Space Science Missions

    Brophy, John R.; Larson, Tim

    2013-01-01

    The Solar Array System contracts awarded by NASA's Space Technology Mission Directorate are developing solar arrays in the 30 kW to 50 kW power range (beginning of life at 1 AU) that have significantly higher specific powers (W/kg) and much smaller stowed volumes than conventional rigid-panel arrays. The successful development of these solar array technologies has the potential to enable new types of solar electric propulsion (SEP) vehicles and missions. This paper describes a 30-kW electric propulsion vehicle built into an EELV Secondary Payload Adapter (ESPA) ring. The system uses an ESPA ring as the primary structure and packages two 15-kW Megaflex solar array wings, two 14-kW Hall thrusters, a hydrazine Reaction Control Subsystem (RCS), 220 kg of xenon, 26 kg of hydrazine, and an avionics module that contains all of the rest of the spacecraft bus functions and the instrument suite. Direct-drive is used to maximize the propulsion subsystem efficiency and minimize the resulting waste heat and required radiator area. This is critical for packaging a high-power spacecraft into a very small volume. The fully-margined system dry mass would be approximately 1120 kg. This is not a small dry mass for a Discovery-class spacecraft, for example, the Dawn spacecraft dry mass was only about 750 kg. But the Dawn electric propulsion subsystem could process a maximum input power of 2.5 kW, and this spacecraft would process 28 kW, an increase of more than a factor of ten. With direct-drive the specific impulse would be limited to about 2,000 s assuming a nominal solar array output voltage of 300 V. The resulting spacecraft would have a beginning of life acceleration that is more than an order of magnitude greater than the Dawn spacecraft. Since the spacecraft would be built into an ESPA ring it could be launched as a secondary payload to a geosynchronous transfer orbit significantly reducing the launch costs for a planetary spacecraft. The SEP system would perform the escape

  2. The Director's Work on Himself

    Kuhlmann, Annelis

    2008-01-01

    A reading of Stanislavsky's major works about the actor's work on himself from the viewpoint of the director's work on himself.......A reading of Stanislavsky's major works about the actor's work on himself from the viewpoint of the director's work on himself....

  3. IT governance guidelines for directors

    Calder, Alan

    2005-01-01

    This important new book – 'IT Governance: Guidelines for Directors' provides directors, executives, managers and professional advisers with clear, pragmatic guidelines for ensuring that IT and the business work together for the same strategic objectives. 

  4. Three directors for one strategy

    2009-01-01

    Following the interview with the Director General, Rolf-Dieter Heuer, the Bulletin continues its series of interviews with the members of CERN’s new Management team. This week, the Bulletin interviewed the three Directors, who presented their strategies for their respective sectors as a new era begins for CERN.

  5. Object Oriented Programming in Director

    Marian DARDALA

    2006-01-01

    Full Text Available Director is one of the most popular authoring software. As software for developing multimedia applications, Director is an object oriented programming environment. A very important issue to develop multimedia applications is the designing of their own classes. This paper presents the particular aspects concerning the available facilities offered by Lingo to design classes and to generate objects.

  6. NASA Spacecraft Fault Management Workshop Results

    Newhouse, Marilyn; McDougal, John; Barley, Bryan; Fesq, Lorraine; Stephens, Karen

    2010-01-01

    Fault Management is a critical aspect of deep-space missions. For the purposes of this paper, fault management is defined as the ability of a system to detect, isolate, and mitigate events that impact, or have the potential to impact, nominal mission operations. The fault management capabilities are commonly distributed across flight and ground subsystems, impacting hardware, software, and mission operations designs. The National Aeronautics and Space Administration (NASA) Discovery & New Frontiers (D&NF) Program Office at Marshall Space Flight Center (MSFC) recently studied cost overruns and schedule delays for 5 missions. The goal was to identify the underlying causes for the overruns and delays, and to develop practical mitigations to assist the D&NF projects in identifying potential risks and controlling the associated impacts to proposed mission costs and schedules. The study found that 4 out of the 5 missions studied had significant overruns due to underestimating the complexity and support requirements for fault management. As a result of this and other recent experiences, the NASA Science Mission Directorate (SMD) Planetary Science Division (PSD) commissioned a workshop to bring together invited participants across government, industry, academia to assess the state of the art in fault management practice and research, identify current and potential issues, and make recommendations for addressing these issues. The workshop was held in New Orleans in April of 2008. The workshop concluded that fault management is not being limited by technology, but rather by a lack of emphasis and discipline in both the engineering and programmatic dimensions. Some of the areas cited in the findings include different, conflicting, and changing institutional goals and risk postures; unclear ownership of end-to-end fault management engineering; inadequate understanding of the impact of mission-level requirements on fault management complexity; and practices, processes, and

  7. Spacecraft Thermal Management

    Hurlbert, Kathryn Miller

    2009-01-01

    In the 21st century, the National Aeronautics and Space Administration (NASA), the Russian Federal Space Agency, the National Space Agency of Ukraine, the China National Space Administration, and many other organizations representing spacefaring nations shall continue or newly implement robust space programs. Additionally, business corporations are pursuing commercialization of space for enabling space tourism and capital business ventures. Future space missions are likely to include orbiting satellites, orbiting platforms, space stations, interplanetary vehicles, planetary surface missions, and planetary research probes. Many of these missions will include humans to conduct research for scientific and terrestrial benefits and for space tourism, and this century will therefore establish a permanent human presence beyond Earth s confines. Other missions will not include humans, but will be autonomous (e.g., satellites, robotic exploration), and will also serve to support the goals of exploring space and providing benefits to Earth s populace. This section focuses on thermal management systems for human space exploration, although the guiding principles can be applied to unmanned space vehicles as well. All spacecraft require a thermal management system to maintain a tolerable thermal environment for the spacecraft crew and/or equipment. The requirements for human rating and the specified controlled temperature range (approximately 275 K - 310 K) for crewed spacecraft are unique, and key design criteria stem from overall vehicle and operational/programatic considerations. These criteria include high reliability, low mass, minimal power requirements, low development and operational costs, and high confidence for mission success and safety. This section describes the four major subsystems for crewed spacecraft thermal management systems, and design considerations for each. Additionally, some examples of specialized or advanced thermal system technologies are presented

  8. 3D Display of Spacecraft Dynamics Using Real Telemetry

    Sanguk Lee

    2002-12-01

    Full Text Available 3D display of spacecraft motion by using telemetry data received from satellite in real-time is described. Telemetry data are converted to the appropriate form for 3-D display by the real-time preprocessor. Stored playback telemetry data also can be processed for the display. 3D display of spacecraft motion by using real telemetry data provides intuitive comprehension of spacecraft dynamics.

  9. Boards: Independent and Committed Directors?

    Christophe Volonté

    2011-01-01

    Regulators, proxy advisors and shareholders are regularly calling for independent directors. However, at the same time, independent directors commonly engage in numerous outside activities potentially reducing their time and commitment with the particular firm. Using Tobin's Q as an approximation of market valuation and controlling for endogeneity, our empirical analysis reveals that neither is independence positively related to firm performance nor are outside activities negatively related t...

  10. Spacecraft exploration of asteroids

    Veverka, J.; Langevin, Y.; Farquhar, R.; Fulchignoni, M.

    1989-01-01

    After two decades of spacecraft exploration, we still await the first direct investigation of an asteroid. This paper describes how a growing international interest in the solar system's more primitive bodies should remedy this. Plans are under way in Europe for a dedicated asteroid mission (Vesta) which will include multiple flybys with in situ penetrator studies. Possible targets include 4 Vesta, 8 Flora and 46 Hestia; launch its scheduled for 1994 or 1996. In the United States, NASA plans include flybys of asteroids en route to outer solar system targets

  11. Spacecraft rendezvous and docking

    Jørgensen, John Leif

    1999-01-01

    The phenomenons and problems encountered when a rendezvous manoeuvre, and possible docking, of two spacecrafts has to be performed, have been the topic for numerous studies, and, details of a variety of scenarios has been analysed. So far, all solutions that has been brought into realization has...... been based entirely on direct human supervision and control. This paper describes a vision-based system and methodology, that autonomously generates accurate guidance information that may assist a human operator in performing the tasks associated with both the rendezvous and docking navigation...

  12. Toward autonomous spacecraft

    Fogel, L. J.; Calabrese, P. G.; Walsh, M. J.; Owens, A. J.

    1982-01-01

    Ways in which autonomous behavior of spacecraft can be extended to treat situations wherein a closed loop control by a human may not be appropriate or even possible are explored. Predictive models that minimize mean least squared error and arbitrary cost functions are discussed. A methodology for extracting cyclic components for an arbitrary environment with respect to usual and arbitrary criteria is developed. An approach to prediction and control based on evolutionary programming is outlined. A computer program capable of predicting time series is presented. A design of a control system for a robotic dense with partially unknown physical properties is presented.

  13. Additive Manufacturing: Ensuring Quality for Spacecraft Applications

    Swanson, Theodore; Stephenson, Timothy

    2014-01-01

    Reliable manufacturing requires that material properties and fabrication processes be well defined in order to insure that the manufactured parts meet specified requirements. While this issue is now relatively straightforward for traditional processes such as subtractive manufacturing and injection molding, this capability is still evolving for AM products. Hence, one of the principal challenges within AM is in qualifying and verifying source material properties and process control. This issue is particularly critical for applications in harsh environments and demanding applications, such as spacecraft.

  14. Directors of the Future

    Buur, Jacob; Arnal, Luis; Have, Claus

    in a storytelling process with actors from the Dacapo Theatre to create a concrete scenario of what the future might hold. Theatre has the capacity to speak directly to personal experiences and emotions. With this panel we wanted to move beyond the slightly distanced, reflective stance that ethnographers may take...

  15. Automating Trend Analysis for Spacecraft Constellations

    Davis, George; Cooter, Miranda; Updike, Clark; Carey, Everett; Mackey, Jennifer; Rykowski, Timothy; Powers, Edward I. (Technical Monitor)

    2001-01-01

    missions such as DRACO with the intent that mission operations costs be significantly reduced. The goal of the Constellation Spacecraft Trend Analysis Toolkit (CSTAT) project is to serve as the pathfinder for a fully automated trending system to support spacecraft constellations. The development approach to be taken is evolutionary. In the first year of the project, the intent is to significantly advance the state of the art in current trending systems through improved functionality and increased automation. In the second year, the intent is to add an expert system shell, likely through the adaptation of an existing commercial-off-the-shelf (COTS) or government-off-the-shelf (GOTS) tool to implement some level of the trending intelligence that humans currently provide in manual operations. In the third year, the intent is to infuse the resulting technology into a near-term constellation or formation-flying mission to test it and gain experience in automated trending. The lessons learned from the real missions operations experience will then be used to improve the system, and to ultimately incorporate it into a fully autonomous, closed-loop mission operations system that is truly capable of supporting large constellations. In this paper, the process of automating trend analysis for spacecraft constellations will be addressed. First, the results of a survey on automation in spacecraft mission operations in general, and in trending systems in particular will be presented to provide an overview of the current state of the art. Next, a rule-based model for implementing intelligent spacecraft subsystem trending will be then presented, followed by a survey of existing COTS/GOTS tools that could be adapted for implementing such a model. The baseline design and architecture of the CSTAT system will be presented. Finally, some results obtained from initial software tests and demonstrations will be presented.

  16. U.S. Senate confirms new USGS director

    Showstack, Randy

    Shortly before adjourning in October, the U.S. Senate confirmed Charles Groat as the new director of the U.S. Geological Survey. Interior Secretary Bruce Babbitt is expected to swear him in shortly as the agency's 13th director. Groat takes over from Thomas Casadevall, who has served as acting director since Gordon Eaton resigned in September 1997.Groat, an AGU member, has more than 25 years of experience in the Earth science fields, including energy and minerals resource assessment, groundwater occurrence and protection, geomorphic processes and landform evolution in desert areas, and coastal studies.

  17. Hospital management's linchpin: the medical director.

    Cohn, R E

    1988-01-01

    The practice of medicine has become increasingly complex in this era of diagnosis-related groups (DRGs) and other direct government involvement in health care; complex and seemingly inappropriate legal decisions; liability chaos; and increasing competition from peers, entrepreneurs, and other health care organizations. In this new environment, an old player, the medical director (vice president of medical affairs) has been given new visibility and increased responsibilities to help physicians live with and overcome these environmental factors. In showing how the medical director can be of assistance in putting these factors into perspective, it is helpful to take a look at some aspects of the history of medicine, analyze the education process for physicians, point out where the profession began to be driven off course, and identify some of the overall problems of the profession and of the health care field. It is my intent here to project the position of medical director as a vital, frequently missing, link in the attempt to maximize communications, understanding, and achievement in health care organizations.

  18. Guidance and control of swarms of spacecraft

    Morgan, Daniel James

    using computer simulations. The swarm-keeping problem can be solved by placing the spacecraft on J2-invariant relative orbits, which prevent collisions and minimize the drift of the swarm over hundreds of orbits using a single burn. These orbits are achieved by energy matching the spacecraft to the reference orbit. Additionally, these conditions can be repeatedly applied to minimize the drift of the swarm when atmospheric drag has a large effect (orbits with an altitude under 500 km). The swarm reconfiguration is achieved using two steps: trajectory optimization and assignment. The trajectory optimization problem can be written as a nonlinear, optimal control problem. This optimal control problem is discretized, decoupled, and convexified so that the individual femtosats can efficiently solve the optimization. Sequential convex programming is used to generate the control sequences and trajectories required to safely and efficiently transfer a spacecraft from one position to another. The sequence of trajectories is shown to converge to a Karush-Kuhn-Tucker point of the nonconvex problem. In the case where many of the spacecraft are interchangeable, a variable-swarm, distributed auction algorithm is used to determine the assignment of spacecraft to target positions. This auction algorithm requires only local communication and all of the bidding parameters are stored locally. The assignment generated using this auction algorithm is shown to be near optimal and to converge in a finite number of bids. Additionally, the bidding process is used to modify the number of targets used in the assignment so that the reconfiguration can be achieved even when there is a disconnected communication network or a significant loss of agents. Once the assignment is achieved, the trajectory optimization can be run using the terminal positions determined by the auction algorithm. To implement these algorithms in real time a model predictive control formulation is used. Model predictive

  19. Small Spacecraft for Planetary Science

    Baker, John; Castillo-Rogez, Julie; Bousquet, Pierre-W.; Vane, Gregg; Komarek, Tomas; Klesh, Andrew

    2016-07-01

    As planetary science continues to explore new and remote regions of the Solar system with comprehensive and more sophisticated payloads, small spacecraft offer the possibility for focused and more affordable science investigations. These small spacecraft or micro spacecraft (attitude control and determination, capable computer and data handling, and navigation are being met by technologies currently under development to be flown on CubeSats within the next five years. This paper will discuss how micro spacecraft offer an attractive alternative to accomplish specific science and technology goals and what relevant technologies are needed for these these types of spacecraft. Acknowledgements: Part of this work is being carried out at the Jet Propulsion Laboratory, California Institute of Technology under contract to NASA. Government sponsorship acknowledged.

  20. Fermilab Education Office - Director's Award

    Search The Director's Award Exceptional Service To Fermilab's K-12 Education Programs The many successes of Fermilab's K-12 education programs depend on the talents of the over 200 employees, users, and $1,000, made possible by an anonymous donor to Fermilab Friends for Science Education, recognizes one

  1. The governance of director networks

    Renneboog, L.D.R.; Zhou, Y.; Wright, M.; Siegel, D.; Keasey, K.; Filatotchev, I.

    2013-01-01

    This chapter studies director networks, which have gained increasing attention from sociology, finance, and management. It considers the argument that these networks have an interesting role in corporate governance and then reviews their rules in major developed countries. The chapter goes on to

  2. Printed Spacecraft Separation System

    Dehoff, Ryan R [ORNL; Holmans, Walter [Planetary Systems Corporation

    2016-10-01

    In this project Planetary Systems Corporation proposed utilizing additive manufacturing (3D printing) to manufacture a titanium spacecraft separation system for commercial and US government customers to realize a 90% reduction in the cost and energy. These savings were demonstrated via “printing-in” many of the parts and sub-assemblies into one part, thus greatly reducing the labor associated with design, procurement, assembly and calibration of mechanisms. Planetary Systems Corporation redesigned several of the components of the separation system based on additive manufacturing principles including geometric flexibility and the ability to fabricate complex designs, ability to combine multiple parts of an assembly into a single component, and the ability to optimize design for specific mechanical property targets. Shock absorption was specifically targeted and requirements were established to attenuate damage to the Lightband system from shock of initiation. Planetary Systems Corporation redesigned components based on these requirements and sent the designs to Oak Ridge National Laboratory to be printed. ORNL printed the parts using the Arcam electron beam melting technology based on the desire for the parts to be fabricated from Ti-6Al-4V based on the weight and mechanical performance of the material. A second set of components was fabricated from stainless steel material on the Renishaw laser powder bed technology due to the improved geometric accuracy, surface finish, and wear resistance of the material. Planetary Systems Corporation evaluated these components and determined that 3D printing is potentially a viable method for achieving significant cost and savings metrics.

  3. Spectra and spacecraft

    Moroz, V. I.

    2001-02-01

    In June 1999, Dr. Regis Courtin, Associate Editor of PSS, suggested that I write an article for the new section of this journal: "Planetary Pioneers". I hesitated , but decided to try. One of the reasons for my doubts was my primitive English, so I owe the reader an apology for this in advance. Writing took me much more time than I supposed initially, I have stopped and again returned to manuscript many times. My professional life may be divided into three main phases: pioneering work in ground-based IR astronomy with an emphasis on planetary spectroscopy (1955-1970), studies of the planets with spacecraft (1970-1989), and attempts to proceed with this work in difficult times. I moved ahead using the known method of trials and errors as most of us do. In fact, only a small percentage of efforts led to some important results, a sort of dry residue. I will try to describe below how has it been in my case: what may be estimated as the most important, how I came to this, what was around, etc.

  4. Parameter Estimation of Spacecraft Fuel Slosh Model

    Gangadharan, Sathya; Sudermann, James; Marlowe, Andrea; Njengam Charles

    2004-01-01

    Fuel slosh in the upper stages of a spinning spacecraft during launch has been a long standing concern for the success of a space mission. Energy loss through the movement of the liquid fuel in the fuel tank affects the gyroscopic stability of the spacecraft and leads to nutation (wobble) which can cause devastating control issues. The rate at which nutation develops (defined by Nutation Time Constant (NTC can be tedious to calculate and largely inaccurate if done during the early stages of spacecraft design. Pure analytical means of predicting the influence of onboard liquids have generally failed. A strong need exists to identify and model the conditions of resonance between nutation motion and liquid modes and to understand the general characteristics of the liquid motion that causes the problem in spinning spacecraft. A 3-D computerized model of the fuel slosh that accounts for any resonant modes found in the experimental testing will allow for increased accuracy in the overall modeling process. Development of a more accurate model of the fuel slosh currently lies in a more generalized 3-D computerized model incorporating masses, springs and dampers. Parameters describing the model include the inertia tensor of the fuel, spring constants, and damper coefficients. Refinement and understanding the effects of these parameters allow for a more accurate simulation of fuel slosh. The current research will focus on developing models of different complexity and estimating the model parameters that will ultimately provide a more realistic prediction of Nutation Time Constant obtained through simulation.

  5. Streamlined Modeling for Characterizing Spacecraft Anomalous Behavior

    Klem, B.; Swann, D.

    2011-09-01

    Anomalous behavior of on-orbit spacecraft can often be detected using passive, remote sensors which measure electro-optical signatures that vary in time and spectral content. Analysts responsible for assessing spacecraft operational status and detecting detrimental anomalies using non-resolved imaging sensors are often presented with various sensing and identification issues. Modeling and measuring spacecraft self emission and reflected radiant intensity when the radiation patterns exhibit a time varying reflective glint superimposed on an underlying diffuse signal contribute to assessment of spacecraft behavior in two ways: (1) providing information on body component orientation and attitude; and, (2) detecting changes in surface material properties due to the space environment. Simple convex and cube-shaped spacecraft, designed to operate without protruding solar panel appendages, may require an enhanced level of preflight characterization to support interpretation of the various physical effects observed during on-orbit monitoring. This paper describes selected portions of the signature database generated using streamlined signature modeling and simulations of basic geometry shapes apparent to non-imaging sensors. With this database, summarization of key observable features for such shapes as spheres, cylinders, flat plates, cones, and cubes in specific spectral bands that include the visible, mid wave, and long wave infrared provide the analyst with input to the decision process algorithms contained in the overall sensing and identification architectures. The models typically utilize baseline materials such as Kapton, paints, aluminum surface end plates, and radiators, along with solar cell representations covering the cylindrical and side portions of the spacecraft. Multiple space and ground-based sensors are assumed to be located at key locations to describe the comprehensive multi-viewing aspect scenarios that can result in significant specular reflection

  6. Application of gyrotheodolite for alignment in large spacecraft installation process%陀螺经纬仪在大型航天产品精测中的应用

    任春珍; 季宇; 孙刚

    2011-01-01

    The gyrotheodolite is a kind of orientation instrument commonly used for determining the azimuth angle relative to the local North. In the AIT process of Tiangong-Ⅰ target spacecraft, it is required to determine the attitude of two devices at operation platforms of different heights. On that condition, two theodolites may be blocked due to alignment between each other, thus it is unable to set up the relationship between the datum cube mirrors. To solve that problem, the geodetic coordinates are used as a transfer coordinate system to obtain the angle relationships. This new method for gyrotheodolite measurement is shown to be feasible with a satisfactory error analysis result, which can be used for similar precision measurements of large spacecraft.%陀螺经纬仪通常是做某一方向与当地大地北向的方位角关系测量用.文章针对“天宫一号”目标飞行器精测中遇到的问题,即高空不同平台间两台设备需要姿态关系测量的需求,通过对陀螺经纬仪测量原理的研究,借助大地坐标系作为中间传递坐标系,解决了经纬仪测量因互瞄被遮挡无法建立基准镜坐标系间关系的问题.测量误差分析结果验证了这种新方法的可行性,该方法可用于大型航天产品设备安装精度的测量.

  7. Hard-real-time resource management for autonomous spacecraft

    Gat, E.

    2000-01-01

    This paper describes tickets, a computational mechanism for hard-real-time autonomous resource management. Autonomous spacecraftcontrol can be considered abstractly as a computational process whose outputs are spacecraft commands.

  8. Bibliography of the space processing program. Volume 1: A compilation through June 1974, Parts 1 and 2. [space manufacturing/spacecraft construction materials - aerospace environments

    Shoultz, M. B.; Mcclurken, E. W., Jr.

    1975-01-01

    A compilation of NASA research efforts in the area of space environmental effects on materials and processes is presented. Topics considered are: (1) fluid mechanics and heat transfer; (2) crystal growth and containerless melts; (3) acoustics; (4) glass and ceramics; (5) electrophoresis; (6) welding; and (7) exobiology.

  9. Darwinian Spacecraft: Soft Computing Strategies Breeding Better, Faster Cheaper

    Noever, David A.; Baskaran, Subbiah

    1999-01-01

    Computers can create infinite lists of combinations to try to solve a particular problem, a process called "soft-computing." This process uses statistical comparables, neural networks, genetic algorithms, fuzzy variables in uncertain environments, and flexible machine learning to create a system which will allow spacecraft to increase robustness, and metric evaluation. These concepts will allow for the development of a spacecraft which will allow missions to be performed at lower costs.

  10. Deep Space Networking Experiments on the EPOXI Spacecraft

    Jones, Ross M.

    2011-01-01

    NASA's Space Communications & Navigation Program within the Space Operations Directorate is operating a program to develop and deploy Disruption Tolerant Networking [DTN] technology for a wide variety of mission types by the end of 2011. DTN is an enabling element of the Interplanetary Internet where terrestrial networking protocols are generally unsuitable because they rely on timely and continuous end-to-end delivery of data and acknowledgments. In fall of 2008 and 2009 and 2011 the Jet Propulsion Laboratory installed and tested essential elements of DTN technology on the Deep Impact spacecraft. These experiments, called Deep Impact Network Experiment (DINET 1) were performed in close cooperation with the EPOXI project which has responsibility for the spacecraft. The DINET 1 software was installed on the backup software partition on the backup flight computer for DINET 1. For DINET 1, the spacecraft was at a distance of about 15 million miles (24 million kilometers) from Earth. During DINET 1 300 images were transmitted from the JPL nodes to the spacecraft. Then, they were automatically forwarded from the spacecraft back to the JPL nodes, exercising DTN's bundle origination, transmission, acquisition, dynamic route computation, congestion control, prioritization, custody transfer, and automatic retransmission procedures, both on the spacecraft and on the ground, over a period of 27 days. The first DINET 1 experiment successfully validated many of the essential elements of the DTN protocols. DINET 2 demonstrated: 1) additional DTN functionality, 2) automated certain tasks which were manually implemented in DINET 1 and 3) installed the ION SW on nodes outside of JPL. DINET 3 plans to: 1) upgrade the LTP convergence-layer adapter to conform to the international LTP CL specification, 2) add convergence-layer "stewardship" procedures and 3) add the BSP security elements [PIB & PCB]. This paper describes the planning and execution of the flight experiment and the

  11. Spacecraft Charging and the Microwave Anisotropy Probe Spacecraft

    Timothy, VanSant J.; Neergaard, Linda F.

    1998-01-01

    The Microwave Anisotropy Probe (MAP), a MIDEX mission built in partnership between Princeton University and the NASA Goddard Space Flight Center (GSFC), will study the cosmic microwave background. It will be inserted into a highly elliptical earth orbit for several weeks and then use a lunar gravity assist to orbit around the second Lagrangian point (L2), 1.5 million kilometers, anti-sunward from the earth. The charging environment for the phasing loops and at L2 was evaluated. There is a limited set of data for L2; the GEOTAIL spacecraft measured relatively low spacecraft potentials (approx. 50 V maximum) near L2. The main area of concern for charging on the MAP spacecraft is the well-established threat posed by the "geosynchronous region" between 6-10 Re. The launch in the autumn of 2000 will coincide with the falling of the solar maximum, a period when the likelihood of a substorm is higher than usual. The likelihood of a substorm at that time has been roughly estimated to be on the order of 20% for a typical MAP mission profile. Because of the possibility of spacecraft charging, a requirement for conductive spacecraft surfaces was established early in the program. Subsequent NASCAP/GEO analyses for the MAP spacecraft demonstrated that a significant portion of the sunlit surface (solar cell cover glass and sunshade) could have nonconductive surfaces without significantly raising differential charging. The need for conductive materials on surfaces continually in eclipse has also been reinforced by NASCAP analyses.

  12. NASA Workshop on Hybrid (Mixed-Actuator) Spacecraft Attitude Control

    Dennehy, Cornelius J.; Kunz, Nans

    2014-01-01

    At the request of the Science Mission Directorate Chief Engineer, the NASA Technical Fellow for Guidance, Navigation & Control assembled and facilitated a workshop on Spacecraft Hybrid Attitude Control. This multi-Center, academic, and industry workshop, sponsored by the NASA Engineering and Safety Center (NESC), was held in April 2013 to unite nationwide experts to present and discuss the various innovative solutions, techniques, and lessons learned regarding the development and implementation of the various hybrid attitude control system solutions investigated or implemented. This report attempts to document these key lessons learned with the 16 findings and 9 NESC recommendations.

  13. Spacecraft Environmental Interactions Technology, 1983

    1985-01-01

    State of the art of environment interactions dealing with low-Earth-orbit plasmas; high-voltage systems; spacecraft charging; materials effects; and direction of future programs are contained in over 50 papers.

  14. Gravity Probe B spacecraft description

    Bennett, Norman R; Burns, Kevin; Katz, Russell; Kirschenbaum, Jon; Mason, Gary; Shehata, Shawky

    2015-01-01

    The Gravity Probe B spacecraft, developed, integrated, and tested by Lockheed Missiles and Space Company and later Lockheed Martin Corporation, consisted of structures, mechanisms, command and data handling, attitude and translation control, electrical power, thermal control, flight software, and communications. When integrated with the payload elements, the integrated system became the space vehicle. Key requirements shaping the design of the spacecraft were: (1) the tight mission timeline (17 months, 9 days of on-orbit operation), (2) precise attitude and translational control, (3) thermal protection of science hardware, (4) minimizing aerodynamic, magnetic, and eddy current effects, and (5) the need to provide a robust, low risk spacecraft. The spacecraft met all mission requirements, as demonstrated by dewar lifetime meeting specification, positive power and thermal margins, precision attitude control and drag-free performance, reliable communications, and the collection of more than 97% of the available science data. (paper)

  15. Intelligent spacecraft module

    Oungrinis, Konstantinos-Alketas; Liapi, Marianthi; Kelesidi, Anna; Gargalis, Leonidas; Telo, Marinela; Ntzoufras, Sotiris; Paschidi, Mariana

    2014-12-01

    The paper presents the development of an on-going research project that focuses on a human-centered design approach to habitable spacecraft modules. It focuses on the technical requirements and proposes approaches on how to achieve a spatial arrangement of the interior that addresses sufficiently the functional, physiological and psychosocial needs of the people living and working in such confined spaces that entail long-term environmental threats to human health and performance. Since the research perspective examines the issue from a qualitative point of view, it is based on establishing specific relationships between the built environment and its users, targeting people's bodily and psychological comfort as a measure toward a successful mission. This research has two basic branches, one examining the context of the system's operation and behavior and the other in the direction of identifying, experimenting and formulating the environment that successfully performs according to the desired context. The latter aspect is researched upon the construction of a scaled-model on which we run series of tests to identify the materiality, the geometry and the electronic infrastructure required. Guided by the principles of sensponsive architecture, the ISM research project explores the application of the necessary spatial arrangement and behavior for a user-centered, functional interior where the appropriate intelligent systems are based upon the existing mechanical and chemical support ones featured on space today, and especially on the ISS. The problem is set according to the characteristics presented at the Mars500 project, regarding the living quarters of six crew-members, along with their hygiene, leisure and eating areas. Transformable design techniques introduce spatial economy, adjustable zoning and increased efficiency within the interior, securing at the same time precise spatial orientation and character at any given time. The sensponsive configuration is

  16. TTEthernet for Integrated Spacecraft Networks

    Loveless, Andrew

    2015-01-01

    determinism required by real-time spacecraft applications. Even with modern advancements, the uncoordinated (i.e. event-driven) nature of Ethernet communication unavoidably leads to message contention within network switches. The arbitration process used to resolve such conflicts introduces variation in the time it takes for messages to be forwarded. TTEthernet1 introduces decentralized clock synchronization to switched Ethernet, enabling message transmission according to a time-triggered (TT) paradigm. A network planning tool is used to allocate each device a finite amount of time in which it may transmit a frame. Each time slot is repeated sequentially to form a periodic communication schedule that is then loaded onto each TTEthernet device (e.g. switches and end systems). Each network participant references the synchronized time in order to dispatch messages at predetermined instances. This schedule guarantees that no contention exists between time-triggered Ethernet frames in the network switches, therefore eliminating the need for arbitration (and the timing variation it causes). Besides time-triggered messaging, TTEthernet networks may provide two additional traffic classes to support communication of different criticality levels. In the rate-constrained (RC) traffic class, the frame payload size and rate of transmission along each communication channel are limited to predetermined maximums. The network switches can therefore be configured to accommodate the known worst-case traffic pattern, and buffer overflows can be eliminated. The best-effort (BE) traffic class behaves akin to classical Ethernet. No guarantees are provided regarding transmission latency or successful message delivery. TTEthernet coordinates transmission of all three traffic classes over the same physical connections, therefore accommodating the full spectrum of traffic criticality levels required in IMA architectures. Common computing platforms (e.g. LRUs) can share networking resources in such a

  17. 30 CFR 282.11 - Director's authority.

    2010-07-01

    ... CONTINENTAL SHELF FOR MINERALS OTHER THAN OIL, GAS, AND SULPHUR Jurisdiction and Responsibilities of Director § 282.11 Director's authority. (a) In the exercise of jurisdiction under § 282.10, the Director is... of two or more OCS mineral leases or portions of two or more OCS mineral leases into a single mining...

  18. 30 CFR 736.14 - Director's decision.

    2010-07-01

    ... Director shall publish the decision in the Federal Register, including a statement of the basis and purpose... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Director's decision. 736.14 Section 736.14... Director's decision. (a) After considering all relevant information received under § 736.12 of this part...

  19. 12 CFR 7.2010 - Directors' responsibilities.

    2010-01-01

    ... refer to OCC published guidance for additional information regarding responsibilities of directors. ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Directors' responsibilities. 7.2010 Section 7... OPERATIONS Corporate Practices § 7.2010 Directors' responsibilities. The business and affairs of the bank...

  20. Close-Range Photogrammetry & Next Generation Spacecraft

    Pappa, Richard S.

    2002-01-01

    NASA is focusing renewed attention on the topic of large, ultra-lightweight space structures, also known as 'gossamer' spacecraft. Nearly all of the details of the giant spacecraft are still to be worked out. But it's already clear that one of the most challenging aspects will be developing techniques to align and control these systems after they are deployed in space. A critical part of this process is creating new ground test methods to measure gossamer structures under stationary, deploying and vibrating conditions for validation of corresponding analytical predictions. In addressing this problem, I considered, first of all, the possibility of simply using conventional displacement or vibration sensor that could provide spatial measurements. Next, I turned my attention to photogrammetry, a method of determining the spatial coordinates of objects using photographs. The success of this research and development has convinced me that photogrammetry is the most suitable method to solve the gossamer measurement problem.

  1. Evaluation of Ultrafiltration for Spacecraft Water Reuse

    Pickering, Karen D.; Wiesner, Mark R.

    2001-01-01

    Ultrafiltration is examined for use as the first stage of a primary treatment process for spacecraft wastewater. It is hypothesized that ultrafiltration can effectively serve as pretreatment for a reverse osmosis system, removing the majority of organic material in a spacecraft wastewater. However, it is believed that the interaction between the membrane material and the surfactant found in the wastewater will have a significant impact on the fouling of the ultrafiltration membrane. In this study, five different ultrafiltration membrane materials are examined for the filtration of wastewater typical of that expected to be produced onboard the International Space Station. Membranes are used in an unstirred batch cell. Flux, organic carbon rejection, and recovery from fouling are measured. The results of this evaluation will be used to select the most promising membranes for further study.

  2. 26th Conference of Spacecraft TT&C Technology in China

    Qian, Weiping

    2013-01-01

    Proceedings of the 26th Conference of Spacecraft TT&C Technology in China collects selected papers from the 26th Conference of Spacecraft TT&C Technology in China held in Nanjing on October 16-19, 2012. The book features state-of-the-art studies on spacecraft TT&C in China with the theme of “Shared and Flexible TT&C Systems”. The selected works can help  promote development of spacecraft TT&C technology towards interconnectivity, resource sharing, flexibility and high efficiency. Researchers and engineers in the field of aerospace engineering and communication engineering can benefit from the book. Rongjun Shen is the Academician of Chinese Academy of Engineering; Weiping Qian is the Director General of Beijing Institute of Tracking and Telecommunications Technology.

  3. IAEA Director General to Visit Iran

    2012-01-01

    Full text: The Director General of the IAEA, Yukiya Amano, will travel to Tehran this Sunday, 20 May 2012, to discuss issues of mutual interest with high Iranian officials. In the course of his one-day working visit, on Monday 21 May 2012 the Director General will meet the Secretary of Iran's Supreme National Security Council, His Excellency Saeed Jalili, and other senior representatives of the Iranian government. Herman Nackaerts, Deputy Director General for Safeguards, and Rafael Mariano Grossi, Assistant Director General for Policy, will accompany the Director General. (IAEA)

  4. A Technology Program that Rescues Spacecraft

    Deutsch, Leslie J.; Lesh, J. R.

    2004-03-01

    There has never been a long-duration deep space mission that did not have unexpected problems during operations. JPL's Interplanetary Network Directorate (IND) Technology Program was created to develop new and improved methods of communication, navigation, and operations. A side benefit of the program is that it maintains a cadre of human talent and experimental systems that can be brought to bear on unexpected problems that may occur during mission operations. Solutions fall into four categories: applying new technology during operations to enhance science performance, developing new operational strategies, providing domain experts to help find solutions, and providing special facilities to trouble-shoot problems. These are illustrated here using five specific examples of spacecraft anomalies that have been solved using, at least in part, expertise or facilities from the IND Technology Program: Mariner 10, Voyager, Galileo, SOHO, and Cassini/Huygens. In this era of careful cost management, and emphasis on returns-on-investment, it is important to recognize this crucial additional benefit from such technology program investments.

  5. Advanced Solar-propelled Cargo Spacecraft for Mars Missions

    Auziasdeturenne, Jacqueline; Beall, Mark; Burianek, Joseph; Cinniger, Anna; Dunmire, Barbrina; Haberman, Eric; Iwamoto, James; Johnson, Stephen; Mccracken, Shawn; Miller, Melanie

    1989-01-01

    Three concepts for an unmanned, solar powered, cargo spacecraft for Mars support missions were investigated. These spacecraft are designed to carry a 50,000 kg payload from a low Earth orbit to a low Mars orbit. Each design uses a distinctly different propulsion system: A Solar Radiation Absorption (SRA) system, a Solar-Pumped Laser (SPL) system and a solar powered magnetoplasmadynamic (MPD) arc system. The SRA directly converts solar energy to thermal energy in the propellant through a novel process. In the SPL system, a pair of solar-pumped, multi-megawatt, CO2 lasers in sunsynchronous Earth orbit converts solar energy to laser energy. The MPD system used indium phosphide solar cells to convert sunlight to electricity, which powers the propulsion system. Various orbital transfer options are examined for these concepts. In the SRA system, the mother ship transfers the payload into a very high Earth orbit and a small auxiliary propulsion system boosts the payload into a Hohmann transfer to Mars. The SPL spacecraft and the SPL powered spacecraft return to Earth for subsequent missions. The MPD propelled spacecraft, however, remains at Mars as an orbiting space station. A patched conic approximation was used to determine a heliocentric interplanetary transfer orbit for the MPD propelled spacecraft. All three solar-powered spacecraft use an aerobrake procedure to place the payload into a low Mars parking orbit. The payload delivery times range from 160 days to 873 days (2.39 years).

  6. Vibration Antiresonance Design for a Spacecraft Multifunctional Structure

    Li, Dong-Xu; Liu, Wang; Hao, Dong

    2017-01-01

    Spacecraft must withstand rigorous mechanical environment experiences such as acceleration, noise, vibration, and shock during the process of launching, satellite-vehicle separation, and so on. In this paper, a new spacecraft multifunctional structure concept designed by us is introduced. The multifunctional structure has the functions of not only load bearing, but also vibration reduction, energy source, thermal control, and so on, and we adopt a series of viscoelastic parts as connections b...

  7. IRIS Mission Operations Director's Colloquium

    Carvalho, Robert; Mazmanian, Edward A.

    2014-01-01

    Pursuing the Mysteries of the Sun: The Interface Region Imaging Spectrograph (IRIS) Mission. Flight controllers from the IRIS mission will present their individual experiences on IRIS from development through the first year of flight. This will begin with a discussion of the unique nature of IRISs mission and science, and how it fits into NASA's fleet of solar observatories. Next will be a discussion of the critical roles Ames contributed in the mission including spacecraft and flight software development, ground system development, and training for launch. This will be followed by experiences from launch, early operations, ongoing operations, and unusual operations experiences. The presentation will close with IRIS science imagery and questions.

  8. Energy and Environment Directorate Status Report March 2006

    Long, J S

    2006-01-01

    The Energy and Environment Directorate (E and ED) is one of 13 directorates at Lawrence Livermore National Laboratory (LLNL), which is operated by the University of California (UC) for the U.S. Department of Energy's National Nuclear Security Administration (NNSA). We operate in the context of a national security laboratory and focus on meeting major national needs, especially from a long-term perspective. In the LLNL context, E and ED is a hybrid ''program'' and ''discipline'' directorate, combining the program development responsibilities in the national energy and environment arenas to the benefit of the entire Laboratory and also serving as the Laboratory's science base of atmospheric, earth, environmental, and energy science. This Status Report is part of the annual evaluation process required by the Department of Energy (DOE) as part of its contract with UC. The annual review typically will focus on about one third of the activities and programs of a directorate, so that the entire organization is evaluated over a three-year window. This year's review is focused on the basic science foundations for the directorate and two major program areas in the directorate, with an update from a third program. The programs for review are: (1) Earth System Science and Engineering; (2) Nuclear Systems Science and Engineering; and (3) NARAC/IMAAC update. Major questions to be addressed during this review include: (1) Are the programmatic directions appropriate? How can they be improved? (2) What actions can E and ED take to ensure success? How well poised for success are the current staff and facilities? What additions are needed? (3) What recommendations can be made to the Director and the University? This Status Report provides background information on the entire directorate including the parts of the directorate that are the focus of this year's review by the Energy and Environment Directorate Review Committee, to be held March 6-9, 2006. The following sections describe

  9. Artist concept of Galileo spacecraft

    1988-01-01

    Galileo spacecraft is illustrated in artist concept. Gallileo, named for the Italian astronomer, physicist and mathematician who is credited with construction of the first complete, practical telescope in 1620, will make detailed studies of Jupiter. A cooperative program with the Federal Republic of Germany the Galileo mission will amplify information acquired by two Voyager spacecraft in their brief flybys. Galileo is a two-element system that includes a Jupiter-orbiting observatory and an entry probe. Jet Propulsion Laboratory (JPL) is Galileo project manager and builder of the main spacecraft. Ames Research Center (ARC) has responsibility for the entry probe, which was built by Hughes Aircraft Company and General Electric. Galileo will be deployed from the payload bay (PLB) of Atlantis, Orbiter Vehicle (OV) 104, during mission STS-34.

  10. Training for spacecraft technical analysts

    Ayres, Thomas J.; Bryant, Larry

    1989-01-01

    Deep space missions such as Voyager rely upon a large team of expert analysts who monitor activity in the various engineering subsystems of the spacecraft and plan operations. Senior teammembers generally come from the spacecraft designers, and new analysts receive on-the-job training. Neither of these methods will suffice for the creation of a new team in the middle of a mission, which may be the situation during the Magellan mission. New approaches are recommended, including electronic documentation, explicit cognitive modeling, and coached practice with archived data.

  11. Results from active spacecraft potential control on the Geotail spacecraft

    Schmidt, R.; Arends, H.; Pedersen, A.

    1995-01-01

    A low and actively controlled electrostatic potential on the outer surfaces of a scientific spacecraft is very important for accurate measurements of cold plasma electrons and ions and the DC to low-frequency electric field. The Japanese/NASA Geotail spacecraft carriers as part of its scientific payload a novel ion emitter for active control of the electrostatic potential on the surface of the spacecraft. The aim of the ion emitter is to reduce the positive surface potential which is normally encountered in the outer magnetosphere when the spacecraft is sunlit. Ion emission clamps the surface potential to near the ambient plasma potential. Without emission control, Geotail has encountered plasma conditions in the lobes of the magnetotail which resulted in surface potentials of up to about +70 V. The ion emitter proves to be able to discharge the outer surfaces of the spacecraft and is capable of keeping the surface potential stable at about +2 V. This potential is measured with respect to one of the electric field probes which are current biased and thus kept at a potential slightly above the ambient plasma potential. The instrument uses the liquid metal field ion emission principle to emit indium ions. The ion beam energy is about 6 keV and the typical total emission current amounts to about 15 μA. Neither variations in the ambient plasma conditions nor operation of two electron emitters on Geotail produce significant variations of the controlled surface potential as long as the resulting electron emission currents remain much smaller than the ion emission current. Typical results of the active potential control are shown, demonstrating the surface potential reduction and its stability over time. 25 refs., 5 figs

  12. Director general presentation to personnel

    2016-01-01

    Dear Colleagues, Many important discussions are scheduled for the upcoming Council Week (13-17 June) on topics including the Medium-Term Plan, the Pension Fund and other matters of great relevance to us.   I would therefore like to share the main outcome of the week with you and I invite you to join me and the Directors in the Main Auditorium at 10 a.m. on Thursday 23 June. The meeting will last about one hour and a webcast will also be available. Best regards, Fabiola Gianotti DG presentation to personnel Thursday 23 June at 10 am Main Auditorium Retransmission in Council Chamber, IT Auditorium, Kjell Jonhsen Auditorium, Prevessin 864-1-C02 Webcast on cern.ch/webcast More information on the event page.

  13. Institutional directors and board compensation: Spanish evidence

    Felix López-Iturriaga

    2015-07-01

    Full Text Available We address the influence of directors who represent institutional investors in three aspects of board compensation policies: level of compensation, composition, and performance sensitivity. We differentiate pressure-sensitive directors (i.e., with business links and pressure-resistant directors (i.e., without business links. Our results show that pressure-resistant directors decrease total board compensation and its fixed proportion, whereas they increase the variable proportion of total remuneration and the pay-for-performance sensitivity. By contrast, pressure-sensitive directors offer the opposite results. These findings are consistent with the view that institutional investors are not a homogeneous group and that pressure-resistant directors fulfill a more thorough monitoring role.

  14. Charging in the environment of large spacecraft

    Lai, S.T.

    1993-01-01

    This paper discusses some potential problems of spacecraft charging as a result of interactions between a large spacecraft, such as the Space Station, and its environment. Induced electric field, due to VXB effect, may be important for large spacecraft at low earth orbits. Differential charging, due to different properties of surface materials, may be significant when the spacecraft is partly in sunshine and partly in shadow. Triple-root potential jump condition may occur because of differential charging. Sudden onset of severe differential charging may occur when an electron or ion beam is emitted from the spacecraft. The beam may partially return to the ''hot spots'' on the spacecraft. Wake effects, due to blocking of ambient ion trajectories, may result in an undesirable negative potential region in the vicinity of a large spacecraft. Outgassing and exhaust may form a significant spacecraft induced environment; ionization may occur. Spacecraft charging and discharging may affect the electronic components on board

  15. 2011 Computation Directorate Annual Report

    Crawford, D L

    2012-04-11

    From its founding in 1952 until today, Lawrence Livermore National Laboratory (LLNL) has made significant strategic investments to develop high performance computing (HPC) and its application to national security and basic science. Now, 60 years later, the Computation Directorate and its myriad resources and capabilities have become a key enabler for LLNL programs and an integral part of the effort to support our nation's nuclear deterrent and, more broadly, national security. In addition, the technological innovation HPC makes possible is seen as vital to the nation's economic vitality. LLNL, along with other national laboratories, is working to make supercomputing capabilities and expertise available to industry to boost the nation's global competitiveness. LLNL is on the brink of an exciting milestone with the 2012 deployment of Sequoia, the National Nuclear Security Administration's (NNSA's) 20-petaFLOP/s resource that will apply uncertainty quantification to weapons science. Sequoia will bring LLNL's total computing power to more than 23 petaFLOP/s-all brought to bear on basic science and national security needs. The computing systems at LLNL provide game-changing capabilities. Sequoia and other next-generation platforms will enable predictive simulation in the coming decade and leverage industry trends, such as massively parallel and multicore processors, to run petascale applications. Efficient petascale computing necessitates refining accuracy in materials property data, improving models for known physical processes, identifying and then modeling for missing physics, quantifying uncertainty, and enhancing the performance of complex models and algorithms in macroscale simulation codes. Nearly 15 years ago, NNSA's Accelerated Strategic Computing Initiative (ASCI), now called the Advanced Simulation and Computing (ASC) Program, was the critical element needed to shift from test-based confidence to science-based confidence

  16. Airborne particulate matter in spacecraft

    1988-01-01

    Acceptability limits and sampling and monitoring strategies for airborne particles in spacecraft were considered. Based on instances of eye and respiratory tract irritation reported by Shuttle flight crews, the following acceptability limits for airborne particles were recommended: for flights of 1 week or less duration (1 mg/cu m for particles less than 10 microns in aerodynamic diameter (AD) plus 1 mg/cu m for particles 10 to 100 microns in AD); and for flights greater than 1 week and up to 6 months in duration (0.2 mg/cu m for particles less than 10 microns in AD plus 0.2 mg/cu m for particles 10 to 100 microns in AD. These numerical limits were recommended to aid in spacecraft atmosphere design which should aim at particulate levels that are a low as reasonably achievable. Sampling of spacecraft atmospheres for particles should include size-fractionated samples of 0 to 10, 10 to 100, and greater than 100 micron particles for mass concentration measurement and elementary chemical analysis by nondestructive analysis techniques. Morphological and chemical analyses of single particles should also be made to aid in identifying airborne particulate sources. Air cleaning systems based on inertial collection principles and fine particle collection devices based on electrostatic precipitation and filtration should be considered for incorporation into spacecraft air circulation systems. It was also recommended that research be carried out in space in the areas of health effects and particle characterization.

  17. Submarines, spacecraft and exhaled breath.

    Pleil, Joachim D; Hansel, Armin

    2012-03-01

    Foreword The International Association of Breath Research (IABR) meetings are an eclectic gathering of researchers in the medical, environmental and instrumentation fields; our focus is on human health as assessed by the measurement and interpretation of trace chemicals in human exhaled breath. What may have escaped our notice is a complementary field of research that explores the creation and maintenance of artificial atmospheres practised by the submarine air monitoring and air purification (SAMAP) community. SAMAP is comprised of manufacturers, researchers and medical professionals dealing with the engineering and instrumentation to support human life in submarines and spacecraft (including shuttlecraft and manned rockets, high-altitude aircraft, and the International Space Station (ISS)). Here, the immediate concerns are short-term survival and long-term health in fairly confined environments where one cannot simply 'open the window' for fresh air. As such, one of the main concerns is air monitoring and the main sources of contamination are CO(2) and other constituents of human exhaled breath. Since the inaugural meeting in 1994 in Adelaide, Australia, SAMAP meetings have been held every two or three years alternating between the North American and European continents. The meetings are organized by Dr Wally Mazurek (a member of IABR) of the Defense Systems Technology Organization (DSTO) of Australia, and individual meetings are co-hosted by the navies of the countries in which they are held. An overriding focus at SAMAP is life support (oxygen availability and carbon dioxide removal). Certainly, other air constituents are also important; for example, the closed environment of a submarine or the ISS can build up contaminants from consumer products, cooking, refrigeration, accidental fires, propulsion and atmosphere maintenance. However, the most immediate concern is sustaining human metabolism: removing exhaled CO(2) and replacing metabolized O(2). Another

  18. 78 FR 68466 - BLM Director's Response to the Idaho Governor's Appeal of the BLM Idaho State Director's Governor...

    2013-11-14

    ... Bureau of Land Management (BLM) is publishing this notice to explain why the BLM Director is denying the...] BLM Director's Response to the Idaho Governor's Appeal of the BLM Idaho State Director's Governor's... (Finding) to the BLM Idaho State Director (State Director). The State Director determined the Governor's...

  19. 32 CFR Appendix D to Part 247 - AFIS Print Media Directorate

    2010-07-01

    ... for word processing or desktop publishing. All other PMD publications should be requisitioned through... Directorate (PMD), an element of AFIS, develops, publishes, and distributes a variety of print media products.../defenselink/afis/. B. Use of materials published by print media directorate. With the exception of copyrighted...

  20. 25 CFR 1000.67 - How will the Director award planning and negotiation grants?

    2010-04-01

    ... SELF-DETERMINATION AND EDUCATION ACT Other Financial Assistance for Planning and Negotiation Grants for Non-BIA Programs Eligibility and Application Process § 1000.67 How will the Director award planning... 25 Indians 2 2010-04-01 2010-04-01 false How will the Director award planning and negotiation...

  1. Postdramatic Theatre of Director Christoph Marthaler

    Arina R. Shevchenko

    2017-11-01

    Full Text Available The present paper deals with the main tendencies of modern European theatre represented in the creativity of a famous Swiss director Christoph Marthaler. Drama and theatre of the end of the 20th – the beginning of the 21st century were exposed to radical transformation. This change has been reflected in the theory of postdramatic theatre. A contemporary theatre is becoming more visual. Nowadays natural theatrical synthesis of various arts – visual, plastic, verbal, musical becomes an intersection of all kinds of artistic and medial practices as it has never been before. The new drama and theatre decline mimesis as the main principle of attitude to reality, they do not depict and do not reflect life, but strive to create a magic and/or ritual space of performative living and a special type of communication with audience. These peculiarities of modern theatre get a vivid evocation in the works of Christoph Marthaler. Having entered into theatre from music, the director creates his own unique language of art. The article proves that Marthaler’s works are an individual model of postdramatic theatre. The author concludes that its main distinctive feature is to blur the border between musical and dramatic performance. Marthaler does not stage the play – the images appear from musical phrases, fleeting impressions, observations and dramatic improvisations. The analysis enables to claim that the theatre in a real process of performance replaces the mimetic acting today. The applied principles of drama analysis can be used in studying of the other contemporary postdramatic theatre’s models.

  2. Quick Spacecraft Thermal Analysis Tool, Phase II

    National Aeronautics and Space Administration — For spacecraft design and development teams concerned with cost and schedule, the Quick Spacecraft Thermal Analysis Tool (QuickSTAT) is an innovative software suite...

  3. PLAY DIRECTING AND DIRECTORS: AN EVOLUTIONARY ...

    While the theatre director can be seen as the `god of the theatre', he/she can also be seen as a priest and a carrier who must coordinate human and material resources a master and a messenger. Drawing from the above, this paper traces the evolution of play directing and the theatre director in different theatres of the world ...

  4. CERN loses two former Directors-General

    2002-01-01

    Victor Weisskopf, a giant of modern physics and Director General of CERN from 1961-65, died on 21 April. The previous month, Willibald Jentschke, Director General from 1971-75 and founder of the DESY Laboratory in Hamburg, passed away.

  5. Robert Aymar, Director-General of CERN

    Patrice Loïez

    2003-01-01

    Robert Aymar, photographed in 2003 before taking his position as Director-General at CERN, succeeding Luciano Maiani in 2004. At this time, Aymar was director of the International Thermonuclear Experimental Reactor (ITER) although he had already been involved with developments at CERN, chairing the External Review Committee, set up in 2001 in response to the increased cost of the LHC.

  6. Gender Quotas on Board of Directors

    Smith, Nina

    2013-01-01

    Beside arguments of fairness and equal opportunities, it is often argued that gender diversity on boards of directors may improve firm performance, but the empirical results are mixed and often negative. Based on the available research, gender quotas on boards of directors cannot be justified...

  7. Dr. Francis Collins Is New NIH Director

    ... Ph.D., a physician and geneticist, is the new Director of the National Institutes of Health (NIH), part of the U.S. Department of Health and Human Services. President Barack Obama nominated Dr. Collins, who served as Director of ...

  8. J. B. Adams Acting Director-General

    1960-01-01

    After the tragic death of Prof. C. J. Bakker, the Council of CERN held an emergency meeting on May 3, 1960. Following this session, Mr. F. de Rose, President of the Council of the European Organization for Nuclear Research, announced the appointment of Mr. J. B. Adams, Director of the PS division to the post of acting Director-General.

  9. Director Turnover: An Australian Academic Development Study

    Fraser, Kym; Ryan, Yoni

    2012-01-01

    Although it can be argued that directors of central academic development units (ADUs) are critical to the implementation of university teaching and learning strategies, it would appear there is a high director turnover rate. While research in the USA, the UK, and Australia illustrates that ADUs are frequently closed or restructured, that research…

  10. Predictors of Choral Directors' Voice Handicap

    Schwartz, Sandra

    2013-01-01

    Vocal demands of teaching are considerable and these challenges are greater for choral directors who depend on the voice as a musical and instructive instrument. The purpose of this study was to (1) examine choral directors' vocal condition using a modified Voice Handicap Index (VHI), and (2) determine the extent to which the major variables…

  11. New project director for Honduras.

    1984-01-01

    Miguel Machuca has been installed as project director for the Honduras Contraceptive Social Marketing Program (HCSMP). he was selected from a field of candidates with public and private sector experience in marketing, business management and program development. Machuca will direct the development of the social marketing program and work to establish a marketing function within ASHONPLAFA, the sponsoring organization for HCSMP. A major goal is to correct misinformation or lack of information about family planning methods among consumers and reatilers; for example, consumers worry about the side-effects of oral contraceptives (OCs) and many perceive subsidized products to be either experimental or discards. Easily understandable graphic package naterials are being prepared for OCs distributed through the program. Another goal is sales training. The project is scheduled to be launched in March 1984 with distribution of Perla, a standard dose OC. Radio spots and newspaper ads are being prepared to inform consumers that Perla can be purchased through pharmacies and small rural shops at the cost of US$.75/cycle. A low-dose OC, a condom and a vaginal tablet are scheduled to be added to the product line by December 1984. Market research on brand names, packaging and pricing of these products is currently being conducted. According the Machuca, his biggest challenge will be to maintain a balance between the need to comply with the policies and regulations of the various organizations involved with the HCSMP and the simultaneous need to promote and implement the entrepreneurial activities necessary to project goals.

  12. Multiple spacecraft Michelson stellar interferometer

    Stachnik, R. V.; Arnold, D.; Melroy, P.; Mccormack, E. F.; Gezari, D. Y.

    1984-01-01

    Results of an orbital analysis and performance assessment of SAMSI (Spacecraft Array for Michelson Spatial Interferometry) are presented. The device considered includes two one-meter telescopes in orbits which are identical except for slightly different inclinations; the telescopes achieve separations as large as 10 km and relay starlight to a central station which has a one-meter optical delay line in one interferometer arm. It is shown that a 1000-km altitude, zero mean inclination orbit affords natural scanning of the 10-km baseline with departures from optical pathlength equality which are well within the corrective capacity of the optical delay line. Electric propulsion is completely adequate to provide the required spacecraft motions, principally those needed for repointing. Resolution of 0.00001 arcsec and magnitude limits of 15 to 20 are achievable.

  13. Spacecraft Tests of General Relativity

    Anderson, John D.

    1997-01-01

    Current spacecraft tests of general relativity depend on coherent radio tracking referred to atomic frequency standards at the ground stations. This paper addresses the possibility of improved tests using essentially the current system, but with the added possibility of a space-borne atomic clock. Outside of the obvious measurement of the gravitational frequency shift of the spacecraft clock, a successor to the suborbital flight of a Scout D rocket in 1976 (GP-A Project), other metric tests would benefit most directly by a possible improved sensitivity for the reduced coherent data. For purposes of illustration, two possible missions are discussed. The first is a highly eccentric Earth orbiter, and the second a solar-conjunction experiment to measure the Shapiro time delay using coherent Doppler data instead of the conventional ranging modulation.

  14. Attitude Fusion Techniques for Spacecraft

    Bjarnø, Jonas Bækby

    Spacecraft platform instability constitutes one of the most significant limiting factors in hyperacuity pointing and tracking applications, yet the demand for accurate, timely and reliable attitude information is ever increasing. The PhD research project described within this dissertation has...... served to investigate the solution space for augmenting the DTU μASC stellar reference sensor with a miniature Inertial Reference Unit (IRU), thereby obtaining improved bandwidth, accuracy and overall operational robustness of the fused instrument. Present day attitude determination requirements are met...... of the instrument, and affecting operations during agile and complex spacecraft attitude maneuvers. As such, there exists a theoretical foundation for augmenting the high frequency performance of the μASC instrument, by harnessing the complementary nature of optical stellar reference and inertial sensor technology...

  15. Postdoctoral periodontal program directors' perspectives of resident selection.

    Khan, Saba; Carmosino, Andrew J; Yuan, Judy Chia-Chun; Lucchiari, Newton; Kawar, Nadia; Sukotjo, Cortino

    2015-02-01

    Applications for postdoctoral periodontal programs have recently increased. The National Board Dental Examinations (NBDE) has adopted a pass/fail format. The purpose of this study is to examine the criteria used by accredited postdoctoral periodontal programs in the United States to evaluate potential applicants. A secondary purpose was to determine whether the absence of NBDE scores would change program directors' selection process. Basic demographic information of the program directors was also collected. A questionnaire was sent to all 54 program directors of accredited postdoctoral periodontal programs in the United States. The raw data were compiled, descriptive analyses were performed, and results were tabulated and ranked when applicable. Thirty-five of 54 program directors (64.8%) responded to the survey. The five most important factors in selecting residents were: 1) interview ratings; 2) dental school clinical grades; 3) dental school periodontics grades; 4) personal statement; and 5) letters of recommendation. The majority of the programs (94%; n = 33) require an interview, and many (86%; n = 30) have a committee that makes the final decision on candidate acceptance. More than half of the respondents (56%; n = 17) stated that the pass/fail format of the NBDE would affect the decision-making process. This study describes the criteria used by postdoctoral periodontal programs to help select applicants. Interview ratings, dental school grades, personal statements, and letters of recommendation were found to be the most important factors. Results from this study may be helpful for prospective postdoctoral periodontal program applicants in the United States.

  16. Nonlinearity-induced spacecraft tumbling

    Amos, A.K.

    1994-01-01

    An existing tumbling criterion for the dumbbell satellite in planar librations is reexamined and modified to reflect a recently identified tumbling mode associated with the horizontal attitude orientation. It is shown that for any initial attitude there exists a critical angular rate below which the motion is oscillatory and harmonic and beyond which a continuous tumbling will ensue. If the angular rate is at the critical value the spacecraft drifts towards the horizontal attitude from which a spontaneous periodic tumbling occurs

  17. Integrating standard operating procedures with spacecraft automation, Phase I

    National Aeronautics and Space Administration — Spacecraft automation has the potential to assist crew members and spacecraft operators in managing spacecraft systems during extended space missions. Automation can...

  18. Electromagnetic Dissociation and Spacecraft Electronics Damage

    Norbury, John W.

    2016-01-01

    When protons or heavy ions from galactic cosmic rays (GCR) or solar particle events (SPE) interact with target nuclei in spacecraft, there can be two different types of interactions. The more familiar strong nuclear interaction often dominates and is responsible for nuclear fragmentation in either the GCR or SPE projectile nucleus or the spacecraft target nucleus. (Of course, the proton does not break up, except possibly to produce pions or other hadrons.) The less familiar, second type of interaction is due to the very strong electromagnetic fields that exist when two charged nuclei pass very close to each other. This process is called electromagnetic dissociation (EMD) and primarily results in the emission of neutrons, protons and light ions (isotopes of hydrogen and helium). The cross section for particle production is approximately defined as the number of particles produced in nucleus-nucleus collisions or other types of reactions. (There are various kinematic and other factors which multiply the particle number to arrive at the cross section.) Strong, nuclear interactions usually dominate the nuclear reactions of most interest that occur between GCR and target nuclei. However, for heavy nuclei (near Fe and beyond) at high energy the EMD cross section can be much larger than the strong nuclear interaction cross section. This paper poses a question: Are there projectile or target nuclei combinations in the interaction of GCR or SPE where the EMD reaction cross section plays a dominant role? If the answer is affirmative, then EMD mechanisms should be an integral part of codes that are used to predict damage to spacecraft electronics. The question can become more fine-tuned and one can ask about total reaction cross sections as compared to double differential cross sections. These issues will be addressed in the present paper.

  19. Spacecraft computer technology at Southwest Research Institute

    Shirley, D. J.

    1993-01-01

    Southwest Research Institute (SwRI) has developed and delivered spacecraft computers for a number of different near-Earth-orbit spacecraft including shuttle experiments and SDIO free-flyer experiments. We describe the evolution of the basic SwRI spacecraft computer design from those weighing in at 20 to 25 lb and using 20 to 30 W to newer models weighing less than 5 lb and using only about 5 W, yet delivering twice the processing throughput. Because of their reduced size, weight, and power, these newer designs are especially applicable to planetary instrument requirements. The basis of our design evolution has been the availability of more powerful processor chip sets and the development of higher density packaging technology, coupled with more aggressive design strategies in incorporating high-density FPGA technology and use of high-density memory chips. In addition to reductions in size, weight, and power, the newer designs also address the necessity of survival in the harsh radiation environment of space. Spurred by participation in such programs as MSTI, LACE, RME, Delta 181, Delta Star, and RADARSAT, our designs have evolved in response to program demands to be small, low-powered units, radiation tolerant enough to be suitable for both Earth-orbit microsats and for planetary instruments. Present designs already include MIL-STD-1750 and Multi-Chip Module (MCM) technology with near-term plans to include RISC processors and higher-density MCM's. Long term plans include development of whole-core processors on one or two MCM's.

  20. The Role of Board of Directors in the Establishment of Risk Management Committee

    Ishak Suhaimi

    2017-01-01

    Full Text Available The objective of the study is to discuss the roles of board of directors in the establishment of risk management committee for Malaysian’s public listed companies. In Malaysia, based on the Malaysian Code on Corporate Governance (MCCG, (2007; 2012 clearly stated the role and responsibility of the board of directors toward the risk management activities. At the Corporate Governance Week 2010 and 2011 as well, the chairman of the Security Commission Malaysia highlighted the responsibility of the board of directors in risk management processes and she expressed concern over the failure of the board of directors to establish appropriate measures for the risk management process in the company. The statement of the chairman of Security Commission Malaysia is in line with MCCG’s best practices (2000; 2007; 2012, i.e., the board of directors should identify principle risks and ensure the implementation of an appropriate system to manage these risks.

  1. Hans Blix appointed Director General

    1981-01-01

    On 1 December 1981, Dr Hans Blix took office as Director General of the International Atomic Energy Agency in succession to Dr Sigvard Eklund who has headed the IAEA since 1961. The Agency's Board of Governors nominated Dr Blix by acclamation on 26 September. His appointment was unanimously approved by the final session of the 25th regular session of the General Conference of the IAEA the same day. The President of the Conference, Ambassador Manaspas Xuto, administered the oath of office to Dr Blix at the final plenary meeting that day. Hans Blix was born in 1928 in Uppsala He studied at the University of Uppsala, at Columbia University, where he was also a research graduate and at Cambridge, where he received his Ph D In 1959 he became Doctor of Laws at the Stockholm University and in 1960 was appointed associate professor in international law. From 1963 to 1976 Dr Blix was Head of Department at the Ministry for Foreign Affairs and served as Legal Adviser on International Law. In 1976 he became Undersecretary of State at the Ministry for Foreign Affairs in charge of international development co-operation He was appointed Minister for Foreign Affairs in October 1978 In September 1979 he was again appointed Undersecretary of State at the Ministry for Foreign Affairs in charge of international development co-operation. Since 1961 he has been a member of Sweden's delegation to the United Nations General Assembly, and from 1962 to 1978 a member of the Swedish delegation to the Conference on Disarmament in Geneva. He has written several books on subjects associated with international and constitutional law and was leader of the Liberal Campaign Committee in favour of retention of the Swedish nuclear energy program in the referendum in 1980

  2. Spacecraft Jitter Attenuation Using Embedded Piezoelectric Actuators

    Belvin, W. Keith

    1995-01-01

    Remote sensing from spacecraft requires precise pointing of measurement devices in order to achieve adequate spatial resolution. Unfortunately, various spacecraft disturbances induce vibrational jitter in the remote sensing instruments. The NASA Langley Research Center has performed analysis, simulations, and ground tests to identify the more promising technologies for minimizing spacecraft pointing jitter. These studies have shown that the use of smart materials to reduce spacecraft jitter is an excellent match between a maturing technology and an operational need. This paper describes the use of embedding piezoelectric actuators for vibration control and payload isolation. In addition, recent advances in modeling, simulation, and testing of spacecraft pointing jitter are discussed.

  3. Advanced Smart Structures Flight Experiments for Precision Spacecraft

    Denoyer, Keith K.; Erwin, R. Scott; Ninneman, R. Rory

    2000-07-01

    This paper presents an overview as well as data from four smart structures flight experiments directed by the U.S. Air Force Research Laboratory's Space Vehicles Directorate in Albuquerque, New Mexico. The Middeck Active Control Experiment $¯Flight II (MACE II) is a space shuttle flight experiment designed to investigate modeling and control issues for achieving high precision pointing and vibration control of future spacecraft. The Advanced Controls Technology Experiment (ACTEX-I) is an experiment that has demonstrated active vibration suppression using smart composite structures with embedded piezoelectric sensors and actuators. The Satellite Ultraquiet Isolation Technology Experiment (SUITE) is an isolation platform that uses active piezoelectric actuators as well as damped mechanical flexures to achieve hybrid passive/active isolation. The Vibration Isolation, Suppression, and Steering Experiment (VISS) is another isolation platform that uses viscous dampers in conjunction with electromagnetic voice coil actuators to achieve isolation as well as a steering capability for an infra-red telescope.

  4. What every library director should know

    Curzon, Susan Carol

    2014-01-01

    What Every Library Director Should Know is the insider's view of vital actions, behaviors and strategies to succeed in every type of library. The content is based both on the author's direct experience after a long career in several types of libraries but also on the direct observation of other managers. Inset into the book are pearls of wisdom from other directors, managers and observers who are answering the question, "what is the one piece of management wisdom that you would give to anyone who wishes to become a library director?" This book will help to get you there by explaining and illus

  5. 78 FR 4435 - BLM Director's Response to the Alaska Governor's Appeal of the BLM Alaska State Director's...

    2013-01-22

    ... Bureau of Land Management (BLM) is publishing this notice to explain why the BLM Director is rejecting... Director's Response to the Alaska Governor's Appeal of the BLM Alaska State Director's Governor's... the BLM Alaska State Director. The State Director determined the Governor's Finding was outside the...

  6. Spacecraft Design Thermal Control Subsystem

    Miyake, Robert N.

    2008-01-01

    The Thermal Control Subsystem engineers task is to maintain the temperature of all spacecraft components, subsystems, and the total flight system within specified limits for all flight modes from launch to end-of-mission. In some cases, specific stability and gradient temperature limits will be imposed on flight system elements. The Thermal Control Subsystem of "normal" flight systems, the mass, power, control, and sensing systems mass and power requirements are below 10% of the total flight system resources. In general the thermal control subsystem engineer is involved in all other flight subsystem designs.

  7. Computation Directorate 2007 Annual Report

    Henson, V E; Guse, J A

    2008-03-06

    If there is a single word that both characterized 2007 and dominated the thoughts and actions of many Laboratory employees throughout the year, it is transition. Transition refers to the major shift that took place on October 1, when the University of California relinquished management responsibility for Lawrence Livermore National Laboratory (LLNL), and Lawrence Livermore National Security, LLC (LLNS), became the new Laboratory management contractor for the Department of Energy's (DOE's) National Nuclear Security Administration (NNSA). In the 55 years under the University of California, LLNL amassed an extraordinary record of significant accomplishments, clever inventions, and momentous contributions in the service of protecting the nation. This legacy provides the new organization with a built-in history, a tradition of excellence, and a solid set of core competencies from which to build the future. I am proud to note that in the nearly seven years I have had the privilege of leading the Computation Directorate, our talented and dedicated staff has made far-reaching contributions to the legacy and tradition we passed on to LLNS. Our place among the world's leaders in high-performance computing, algorithmic research and development, applications, and information technology (IT) services and support is solid. I am especially gratified to report that through all the transition turmoil, and it has been considerable, the Computation Directorate continues to produce remarkable achievements. Our most important asset--the talented, skilled, and creative people who work in Computation--has continued a long-standing Laboratory tradition of delivering cutting-edge science even in the face of adversity. The scope of those achievements is breathtaking, and in 2007, our accomplishments span an amazing range of topics. From making an important contribution to a Nobel Prize-winning effort to creating tools that can detect malicious codes embedded in commercial

  8. Five question to... Stanislav Reguli, chairman of the board of directors and general director of the GovCo, joint-stock association

    Stuller, P.

    2006-01-01

    In this paper the interview with the MR. Stanislav Reguli, chairman of the board of directors and general director of the GovCo, joint-stock association is published. The state company GovCo, a.s. was originated on April 1, 2006. Process of severance of property from the Slovenske elektrarne, a.s., personnel management of new company as well as organisation of property management are presented

  9. Comprehension of Spacecraft Telemetry Using Hierarchical Specifications of Behavior

    Havelund, Klaus; Joshi, Rajeev

    2014-01-01

    A key challenge in operating remote spacecraft is that ground operators must rely on the limited visibility available through spacecraft telemetry in order to assess spacecraft health and operational status. We describe a tool for processing spacecraft telemetry that allows ground operators to impose structure on received telemetry in order to achieve a better comprehension of system state. A key element of our approach is the design of a domain-specific language that allows operators to express models of expected system behavior using partial specifications. The language allows behavior specifications with data fields, similar to other recent runtime verification systems. What is notable about our approach is the ability to develop hierarchical specifications of behavior. The language is implemented as an internal DSL in the Scala programming language that synthesizes rules from patterns of specification behavior. The rules are automatically applied to received telemetry and the inferred behaviors are available to ground operators using a visualization interface that makes it easier to understand and track spacecraft state. We describe initial results from applying our tool to telemetry received from the Curiosity rover currently roving the surface of Mars, where the visualizations are being used to trend subsystem behaviors, in order to identify potential problems before they happen. However, the technology is completely general and can be applied to any system that generates telemetry such as event logs.

  10. Telemetry Timing Analysis for Image Reconstruction of Kompsat Spacecraft

    Jin-Ho Lee

    2000-06-01

    Full Text Available The KOMPSAT (KOrea Multi-Purpose SATellite has two optical imaging instruments called EOC (Electro-Optical Camera and OSMI (Ocean Scanning Multispectral Imager. The image data of these instruments are transmitted to ground station and restored correctly after post-processing with the telemetry data transferred from KOMPSAT spacecraft. The major timing information of the KOMPSAT is OBT (On-Board Time which is formatted by the on-board computer of the spacecraft, based on 1Hz sync. pulse coming from the GPS receiver involved. The OBT is transmitted to ground station with the house-keeping telemetry data of the spacecraft while it is distributed to the instruments via 1553B data bus for synchronization during imaging and formatting. The timing information contained in the spacecraft telemetry data would have direct relation to the image data of the instruments, which should be well explained to get a more accurate image. This paper addresses the timing analysis of the KOMPSAT spacecraft and instruments, including the gyro data timing analysis for the correct restoration of the EOC and OSMI image data at ground station.

  11. Digital image transformation and rectification of spacecraft and radar images

    Wu, S. S. C.

    1985-01-01

    The application of digital processing techniques to spacecraft television pictures and radar images is discussed. The use of digital rectification to produce contour maps from spacecraft pictures is described; images with azimuth and elevation angles are converted into point-perspective frame pictures. The digital correction of the slant angle of radar images to ground scale is examined. The development of orthophoto and stereoscopic shaded relief maps from digital terrain and digital image data is analyzed. Digital image transformations and rectifications are utilized on Viking Orbiter and Lander pictures of Mars.

  12. Application of square-root filtering for spacecraft attitude control

    Sorensen, J. A.; Schmidt, S. F.; Goka, T.

    1978-01-01

    Suitable digital algorithms are developed and tested for providing on-board precision attitude estimation and pointing control for potential use in the Landsat-D spacecraft. These algorithms provide pointing accuracy of better than 0.01 deg. To obtain necessary precision with efficient software, a six state-variable square-root Kalman filter combines two star tracker measurements to update attitude estimates obtained from processing three gyro outputs. The validity of the estimation and control algorithms are established, and the sensitivity of their performance to various error sources and software parameters are investigated by detailed digital simulation. Spacecraft computer memory, cycle time, and accuracy requirements are estimated.

  13. Directors' report and accounts 1991-1992

    1993-01-01

    This report for Scottish Hydro-Electric PLC contains details of key financial statistics, the financial calendar, the Directors' Report, the Auditors' Report, accounting policies, a Group Profit and Loss Account, balance sheets and a Group Cash Flow Statement. (UK)

  14. Regional Director | IDRC - International Development Research ...

    ... its effective utilization in the design and execution of the IDRC strategic plan. ... Provides assistance to Program Managers/Leaders, Directors of Program Areas, ... the Partnership and Business Development Division and Programs Branch.

  15. Leader in Digital Transformation: Director, Information Management ...

    As the Deputy Chief Information Officer, the Director is also accountable for developing ... operations and maintenance of key business systems (financial applications, ... Plays a key role in the control of access to personal information in e-mail ...

  16. Selected Publications by the NCI Director

    Dr. Norman Sharpless's written work on cancer research appears in many leading scientific journals, as well as a variety of other publications. This page lists some of the articles published by Dr. Sharpless since becoming NCI director.

  17. Wanted: Fermilab director who can build consensus

    Pierce, G M

    2004-01-01

    "With current Fermilab Director Michael Witherell stepping down in July 2005, an appointed committee has vowed to find a new leader who will keep the Batavia lab at the forefront of the high-energy physics field" (1 page).

  18. Precision pointing of imaging spacecraft using gyro-based attitude ...

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    three-axis attitude of the spacecraft is required continuously for the controller. Gyros provide .... Right ascension of ascending node ( ). 78·1290476 ... U = {ω1 + ω0X,ω2 + ω0Y ,ω3 + ω0Z,} are the process inputs and the matrices A, B and G.

  19. Benefits of Spacecraft Level Vibration Testing

    Gordon, Scott; Kern, Dennis L.

    2015-01-01

    NASA-HDBK-7008 Spacecraft Level Dynamic Environments Testing discusses the approaches, benefits, dangers, and recommended practices for spacecraft level dynamic environments testing, including vibration testing. This paper discusses in additional detail the benefits and actual experiences of vibration testing spacecraft for NASA Goddard Space Flight Center (GSFC) and Jet Propulsion Laboratory (JPL) flight projects. JPL and GSFC have both similarities and differences in their spacecraft level vibration test approach: JPL uses a random vibration input and a frequency range usually starting at 5 Hz and extending to as high as 250 Hz. GSFC uses a sine sweep vibration input and a frequency range usually starting at 5 Hz and extending only to the limits of the coupled loads analysis (typically 50 to 60 Hz). However, both JPL and GSFC use force limiting to realistically notch spacecraft resonances and response (acceleration) limiting as necessary to protect spacecraft structure and hardware from exceeding design strength capabilities. Despite GSFC and JPL differences in spacecraft level vibration test approaches, both have uncovered a significant number of spacecraft design and workmanship anomalies in vibration tests. This paper will give an overview of JPL and GSFC spacecraft vibration testing approaches and provide a detailed description of spacecraft anomalies revealed.

  20. Alternative Perspectives on Independence of Directors

    Brennan, Niamh; McDermott, Michael

    2004-01-01

    This paper examines the issue of independence of boards of directors and non-executive directors of companies listed on the Irish Stock Exchange. Based on information published in annual reports, the study found that most Irish listed companies were complying with the Combined Code’s recommendations for a balanced board structure, albeit with only 60 per cent having majority-independent boards. The study found a lack of consistency in interpreting the definition of “independence”, a lack of d...

  1. Board Directors and Corporate Social Responsibility

    Mariana Nedelcu (Bunea

    2014-08-01

    Full Text Available The boards of directors and corporate social responsibility (CSR have been the subject of much study and debate in the corporate governance circles over the two last decades. With issues ranging from poor corporate reporting to excessive executive compensation often splashed in the headlines, the role of boards comes into the media limelight as never before. Boards of directors are also becoming increasingly aware of corporate social responsibility issues.

  2. Board Directors and Corporate Social Responsibility

    Mariana Nedelcu (Bunea)

    2014-01-01

    The boards of directors and corporate social responsibility (CSR) have been the subject of much study and debate in the corporate governance circles over the two last decades. With issues ranging from poor corporate reporting to excessive executive compensation often splashed in the headlines, the role of boards comes into the media limelight as never before. Boards of directors are also becoming increasingly aware of corporate social responsibility issues.

  3. VMware vCloud director cookbook

    Langenhan, Daniel

    2013-01-01

    VMware vCloud Director Cookbook will adopt a Cookbook-based approach. Packed with illustrations and programming examples, this book explains the simple as well as the complex recipes in an easy-to-understand language.""VMware vCloud Director Cookbook"" is aimed at system administrators and technical architects moving from a virtualized environment to cloud environments. Familiarity with cloud computing platforms and some knowledge of virtualization and managing cloud environments is expected.

  4. Hybrid spacecraft attitude control system

    Renuganth Varatharajoo

    2016-02-01

    Full Text Available The hybrid subsystem design could be an attractive approach for futurespacecraft to cope with their demands. The idea of combining theconventional Attitude Control System and the Electrical Power System ispresented in this article. The Combined Energy and Attitude ControlSystem (CEACS consisting of a double counter rotating flywheel assemblyis investigated for small satellites in this article. Another hybrid systemincorporating the conventional Attitude Control System into the ThermalControl System forming the Combined Attitude and Thermal ControlSystem (CATCS consisting of a "fluid wheel" and permanent magnets isalso investigated for small satellites herein. The governing equationsdescribing both these novel hybrid subsystems are presented and theironboard architectures are numerically tested. Both the investigated novelhybrid spacecraft subsystems comply with the reference missionrequirements.The hybrid subsystem design could be an attractive approach for futurespacecraft to cope with their demands. The idea of combining theconventional Attitude Control System and the Electrical Power System ispresented in this article. The Combined Energy and Attitude ControlSystem (CEACS consisting of a double counter rotating flywheel assemblyis investigated for small satellites in this article. Another hybrid systemincorporating the conventional Attitude Control System into the ThermalControl System forming the Combined Attitude and Thermal ControlSystem (CATCS consisting of a "fluid wheel" and permanent magnets isalso investigated for small satellites herein. The governing equationsdescribing both these novel hybrid subsystems are presented and theironboard architectures are numerically tested. Both the investigated novelhybrid spacecraft subsystems comply with the reference missionrequirements.

  5. Determining Spacecraft Reaction Wheel Friction Parameters

    Sarani, Siamak

    2009-01-01

    Software was developed to characterize the drag in each of the Cassini spacecraft's Reaction Wheel Assemblies (RWAs) to determine the RWA friction parameters. This tool measures the drag torque of RWAs for not only the high spin rates (greater than 250 RPM), but also the low spin rates (less than 250 RPM) where there is a lack of an elastohydrodynamic boundary layer in the bearings. RWA rate and drag torque profiles as functions of time are collected via telemetry once every 4 seconds and once every 8 seconds, respectively. Intermediate processing steps single-out the coast-down regions. A nonlinear model for the drag torque as a function of RWA spin rate is incorporated in order to characterize the low spin rate regime. The tool then uses a nonlinear parameter optimization algorithm based on the Nelder-Mead simplex method to determine the viscous coefficient, the Dahl friction, and the two parameters that account for the low spin-rate behavior.

  6. A spacecraft computer repairable via command.

    Fimmel, R. O.; Baker, T. E.

    1971-01-01

    The MULTIPAC is a central data system developed for deep-space probes with the distinctive feature that it may be repaired during flight via command and telemetry links by reprogramming around the failed unit. The computer organization uses pools of identical modules which the program organizes into one or more computers called processors. The interaction of these modules is dynamically controlled by the program rather than hardware. In the event of a failure, new programs are entered which reorganize the central data system with a somewhat reduced total processing capability aboard the spacecraft. Emphasis is placed on the evolution of the system architecture and the final overall system design rather than the specific logic design.

  7. Estimating Torque Imparted on Spacecraft Using Telemetry

    Lee, Allan Y.; Wang, Eric K.; Macala, Glenn A.

    2013-01-01

    There have been a number of missions with spacecraft flying by planetary moons with atmospheres; there will be future missions with similar flybys. When a spacecraft such as Cassini flies by a moon with an atmosphere, the spacecraft will experience an atmospheric torque. This torque could be used to determine the density of the atmosphere. This is because the relation between the atmospheric torque vector and the atmosphere density could be established analytically using the mass properties of the spacecraft, known drag coefficient of objects in free-molecular flow, and the spacecraft velocity relative to the moon. The density estimated in this way could be used to check results measured by science instruments. Since the proposed methodology could estimate disturbance torque as small as 0.02 N-m, it could also be used to estimate disturbance torque imparted on the spacecraft during high-altitude flybys.

  8. Computer simulation of spacecraft/environment interaction

    Krupnikov, K.K.; Makletsov, A.A.; Mileev, V.N.; Novikov, L.S.; Sinolits, V.V.

    1999-01-01

    This report presents some examples of a computer simulation of spacecraft interaction with space environment. We analysed a set data on electron and ion fluxes measured in 1991-1994 on geostationary satellite GORIZONT-35. The influence of spacecraft eclipse and device eclipse by solar-cell panel on spacecraft charging was investigated. A simple method was developed for an estimation of spacecraft potentials in LEO. Effects of various particle flux impact and spacecraft orientation are discussed. A computer engineering model for a calculation of space radiation is presented. This model is used as a client/server model with WWW interface, including spacecraft model description and results representation based on the virtual reality markup language

  9. Computer simulation of spacecraft/environment interaction

    Krupnikov, K K; Mileev, V N; Novikov, L S; Sinolits, V V

    1999-01-01

    This report presents some examples of a computer simulation of spacecraft interaction with space environment. We analysed a set data on electron and ion fluxes measured in 1991-1994 on geostationary satellite GORIZONT-35. The influence of spacecraft eclipse and device eclipse by solar-cell panel on spacecraft charging was investigated. A simple method was developed for an estimation of spacecraft potentials in LEO. Effects of various particle flux impact and spacecraft orientation are discussed. A computer engineering model for a calculation of space radiation is presented. This model is used as a client/server model with WWW interface, including spacecraft model description and results representation based on the virtual reality markup language.

  10. Novel Round Energy Director for Use with Servo-driven Ultrasonic Welder

    Savitski, Alex; Klinstein, Leo; Holt, Kenneth

    Increasingly stringent process repeatability and precision of assembly requirements are common for high-volume manufacturing for electronic, automotive and especially medical device industries, in which components for disposable medication delivery devices are produced in hundreds of millions annually. Ultrasonic welding, one of the most efficient of plastic welding processes often joins these small plastic parts together, and quite possibly, the one most broadly adopted for high volume assembly. The very fundamental factor in ultrasonic welding process performance is a proper joint design, the most common of which is a design utilizing an energy director. Keeping the energy director size and shape consistent on a part-to-part basis in high volume, multi-cavity operations presents a constant challenge to molded part vendors, as dimensional variations from cavity to cavity and variations in the molding process are always present. A newly developed concept of energy director design, when the tip of the energy director is round, addresses these problems, as the round energy director is significantly easier to mold and maintain its dimensional consistency. It also eliminates a major source of process variability for assembly operations. Materializing the benefits of new type of joint design became possible with the introduction of servo-driven ultrasonic welders, which allow an unprecedented control of material flow during the welding cycle and results in significantly improved process repeatability. This article summarizes results of recent studies focused on evaluating performance of round energy director and investigating the main factors responsible for the joint quality.

  11. Optimal Autonomous Spacecraft Resiliency Maneuvers Using Metaheuristics

    2014-09-15

    This work was accepted for published by the American Institute of Aeronautics and Astronautics (AIAA) Journal of Spacecraft and Rockets in July 2014...publication in the AIAA Journal of Spacecraft and Rockets . Chapter 5 introduces an impulsive maneuvering strategy to deliver a spacecraft to its final...upon arrival r2 and v2 , respectively. The variable T2 determines the time of flight needed to make the maneuver, and the variable θ2 determines the

  12. Operationally Responsive Spacecraft Subsystem, Phase I

    National Aeronautics and Space Administration — Saber Astronautics proposes spacecraft subsystem control software which can autonomously reconfigure avionics for best performance during various mission conditions....

  13. Creative director as a leader El director como líder creativo

    Paulo Felipe Quintero

    2011-12-01

    Full Text Available The current organizational dynamic in the world places universities in a relevant role to be performed in the society. Hence, the concept of “creativity” is studied from the hierarchical levels to understand the implications of completing creative processes within an organization. The creativity in the universities require management plans, which demand effort from strategic leaders to materialize and make the mission tangible to all involved actors in the organization; thus, facilitating the achievement of financial quality results, impact on entrepreneurial spirit and optimal labor climate. Subsequently, the creativity could become a strategic topic in the institutional development plans for the directors. This article shows the theoretical construction of the research Creative Abilities of Private Universities Directors in Manizales and the Relation with the Organizational Climate.La dinámica actual de las organizaciones en el mundo, pone a las universidades en unlugar relevante frente al papel que deben desempeñar en la sociedad. En este sentido, seaborda el concepto de “creatividad” tan de moda en el escenario actual, desde los nivelesjerárquicos, con el fin de entender lo que verdaderamente implica llevar a cabo procesoscreativos en una organización. La creatividad en las universidades requiere mucho másque metas en planes de gestión. Exige un esfuerzo de los líderes estratégicos, para quela misión no se quede en el papel y sea tangible para todos los actores involucradosen la empresa, y de esa manera sea el vehículo para lograr resultados de calidad en lofinanciero, impactos en el espíritu empresarial y ambientes de trabajo óptimos, de modoque la creatividad se convierta para los directores en un tema estratégico en los planesde desarrollo institucional para la excelencia en los climas de trabajo. El presente artículoresultó de la construcción teórica del trabajo de investigación

  14. Defining the management role of the department medical director.

    Brady, T F; Carpenter, C R

    1986-01-01

    Through analysis of medical and administrative director positions it is possible to identify an organizational structure for medical departments that enhances departmental operations. Possible roles and tasks that describe managerial responsibilities are considered, and a review of the literature identifies options for how these roles or tasks can be shared between medical and nonmedical managers at the departmental level. These options are refined based on interviews with department-level managers at a case study hospital. Three models are then explored: unity of command, shared accountability, and split accountability. The unity of command model is recommended. In this model, the medical director assumes total authority and accountability for departmental operations through some sort of "enfranchisement." A more formal planning process and a review of job descriptions are also recommended.

  15. Using neuromorphic optical sensors for spacecraft absolute and relative navigation

    Shake, Christopher M.

    We develop a novel attitude determination system (ADS) for use on nano spacecraft using neuromorphic optical sensors. The ADS intends to support nano-satellite operations by providing low-cost, low-mass, low-volume, low-power, and redundant attitude determination capabilities with quick and straightforward onboard programmability for real time spacecraft operations. The ADS is experimentally validated with commercial-off-the-shelf optical devices that perform sensing and image processing on the same circuit board and are biologically inspired by insects' vision systems, which measure optical flow while navigating in the environment. The firmware on the devices is modified to both perform the additional biologically inspired task of tracking objects and communicate with a PC/104 form-factor embedded computer running Real Time Application Interface Linux used on a spacecraft simulator. Algorithms are developed for operations using optical flow, point tracking, and hybrid modes with the sensors, and the performance of the system in all three modes is assessed using a spacecraft simulator in the Advanced Autonomous Multiple Spacecraft (ADAMUS) laboratory at Rensselaer. An existing relative state determination method is identified to be combined with the novel ADS to create a self-contained navigation system for nano spacecraft. The performance of the method is assessed in simulation and found not to match the results from its authors using only conditions and equations already published. An improved target inertia tensor method is proposed as an update to the existing relative state method, but found not to perform as expected, but is presented for others to build upon.

  16. School directors and management in education

    Srdić Vesna M.

    2015-01-01

    Full Text Available The main features of school management and organization comprise planning, decision making, management, leadership and communication. Research suggests that successful school management requires not only advanced managerial but also leadership skills, with highly developed social skills as the main competence. In a complex social system, good leadership becomes a fundamental component of a successful organization or institution. Although leadership has for a long time been of interest for theoreticians and practitioners alike, there are still numerous questions waiting to be answered in the area of management and leadership in education. According to the Law on the Basis of Educational System, the person who can be named a school director must posses appropriate education, competences, license and experience in education. Legal requirements allow the provision of effective training, but the fact that personal disposition can be both an advantage and an obstacle for acquiring necessary items of knowledge and skills, points to the necessity of including selection into the standard procedure for the election of a director. Democratization and decentralization of the educational system presupposes a series of structural, systemic and functional changes which reflect on school management and the role played by the director. This paper considers responsibilities and competences of directors, both in legislation and in school practice and addresses the question whether a school director is a manager or a leader, and what are the possibilities for the provision of professional resources for school management.

  17. 16 CFR 1000.27 - Directorate for Health Sciences.

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Directorate for Health Sciences. 1000.27... AND FUNCTIONS § 1000.27 Directorate for Health Sciences. The Directorate for Health Sciences is managed by the Associate Executive Director for Health Sciences and is responsible for reviewing and...

  18. 16 CFR 1000.29 - Directorate for Engineering Sciences.

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Directorate for Engineering Sciences. 1000... ORGANIZATION AND FUNCTIONS § 1000.29 Directorate for Engineering Sciences. The Directorate for Engineering Sciences, which is managed by the Associate Executive Director for Engineering Sciences, is responsible for...

  19. 30 CFR 282.10 - Jurisdiction and responsibilities of Director.

    2010-07-01

    ... part and are under the jurisdiction of the Director: Exploration, testing, and mining operations... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Jurisdiction and responsibilities of Director... Jurisdiction and Responsibilities of Director § 282.10 Jurisdiction and responsibilities of Director. Subject...

  20. 16 CFR 1000.26 - Directorate for Epidemiology.

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Directorate for Epidemiology. 1000.26... AND FUNCTIONS § 1000.26 Directorate for Epidemiology. The Directorate for Epidemiology, managed by the Associate Executive Director for Epidemiology, is responsible for the collection and analysis of data on...

  1. Leadership styles of hospital pharmacy directors.

    Parrett, E E; Hurd, P D; Northcraft, G; McGhan, W F; Bootman, J L

    1985-05-01

    The leadership styles of hospital pharmacy directors and the association between leadership style, participative management, and innovative pharmaceutical services were studied using a mail questionnaire. The questionnaire was sent to 570 randomly selected hospital pharmacy directors. Included were a validated instrument that measures task-oriented versus relationship-oriented leadership behavior and other questions about participation of staff members, innovative services, and respondents' personal characteristics. The response rate was 69%. The majority of respondents perceived their leadership as highly relationship-oriented as well as highly task-oriented. Respondents with the "high relationship-high task" leadership style had the highest scores for subordinate participation. There were no significant differences in scores for innovative services by leadership style. A positive correlation between scores for subordinate participation and scores for innovative services was demonstrated. Most hospital pharmacy directors used a management style in which relationships and staff participation were important.

  2. Rolf-Dieter Heuer, next Director General

    CERN Council appointed Professor Rolf-Dieter Heuer to succeed Dr Robert Aymar as CERN’s Director General. Professor Heuer will serve a five-year term, taking office on 1 January 2009. Rolf-Dieter Heuer is currently Research Director for particle and astroparticle physics at Germany’s DESY laboratory in Hamburg. He was a staff member at CERN from 1984 to 1998, working for the OPAL collaboration at LEP, and from 1994 to 1998 he was the collaboration’s spokesman. See the Press Release.

  3. A DUAL NETWORK MODEL OF INTERLOCKING DIRECTORATES

    Humphry Hung

    2003-01-01

    Full Text Available The article proposes an integrative framework for the study of interlocking directorates by using an approach that encompasses the concepts of multiple networks and resource endowment. This serves to integrate the traditional views of interorganizational linkages and intra-class cohesion. Through appropriate strategic analysis of relevant resource endowment of internal environment and external networks of organizations and corporate elites, this article argues that the selection of directors, if used effectively, can be adopted as a strategic device to enhance the corporation's overall performance.

  4. An Empirical Comparison between Two Recursive Filters for Attitude and Rate Estimation of Spinning Spacecraft

    Harman, Richard R.

    2006-01-01

    The advantages of inducing a constant spin rate on a spacecraft are well known. A variety of science missions have used this technique as a relatively low cost method for conducting science. Starting in the late 1970s, NASA focused on building spacecraft using 3-axis control as opposed to the single-axis control mentioned above. Considerable effort was expended toward sensor and control system development, as well as the development of ground systems to independently process the data. As a result, spinning spacecraft development and their resulting ground system development stagnated. In the 1990s, shrinking budgets made spinning spacecraft an attractive option for science. The attitude requirements for recent spinning spacecraft are more stringent and the ground systems must be enhanced in order to provide the necessary attitude estimation accuracy. Since spinning spacecraft (SC) typically have no gyroscopes for measuring attitude rate, any new estimator would need to rely on the spacecraft dynamics equations. One estimation technique that utilized the SC dynamics and has been used successfully in 3-axis gyro-less spacecraft ground systems is the pseudo-linear Kalman filter algorithm. Consequently, a pseudo-linear Kalman filter has been developed which directly estimates the spacecraft attitude quaternion and rate for a spinning SC. Recently, a filter using Markley variables was developed specifically for spinning spacecraft. The pseudo-linear Kalman filter has the advantage of being easier to implement but estimates the quaternion which, due to the relatively high spinning rate, changes rapidly for a spinning spacecraft. The Markley variable filter is more complicated to implement but, being based on the SC angular momentum, estimates parameters which vary slowly. This paper presents a comparison of the performance of these two filters. Monte-Carlo simulation runs will be presented which demonstrate the advantages and disadvantages of both filters.

  5. Investigation of tenuous plasma environment using Active Spacecraft Potential Control (ASPOC) on Magnetospheric Multiscale (MMS) Mission

    Nakamura, Rumi; Jeszenszky, Harald; Torkar, Klaus; Andriopoulou, Maria; Fremuth, Gerhard; Taijmar, Martin; Scharlemann, Carsten; Svenes, Knut; Escoubet, Philippe; Prattes, Gustav; Laky, Gunter; Giner, Franz; Hoelzl, Bernhard

    2015-04-01

    The NASA's Magnetospheric Multiscale (MMS) Mission is planned to be launched on March 12, 2015. The scientific objectives of the MMS mission are to explore and understand the fundamental plasma physics processes of magnetic reconnection, particle acceleration and turbulence in the Earth's magnetosphere. The region of scientific interest of MMS is in a tenuous plasma environment where the positive spacecraft potential reaches an equilibrium at several tens of Volts. An Active Spacecraft Potential Control (ASPOC) instrument neutralizes the spacecraft potential by releasing positive charge produced by indium ion emitters. ASPOC thereby reduces the potential in order to improve the electric field and low-energy particle measurement. The method has been successfully applied on other spacecraft such as Cluster and Double Star. Two ASPOC units are present on each of the MMS spacecraft. Each unit contains four ion emitters, whereby one emitter per instrument is operated at a time. ASPOC for MMS includes new developments in the design of the emitters and the electronics enabling lower spacecraft potentials, higher reliability, and a more uniform potential structure in the spacecraft's sheath compared to previous missions. Model calculations confirm the findings from previous applications that the plasma measurements will not be affected by the beam's space charge. A perfectly stable spacecraft potential precludes the utilization of the spacecraft as a plasma probe, which is a conventional technique used to estimate ambient plasma density from the spacecraft potential. The small residual variations of the potential controlled by ASPOC, however, still allow to determine ambient plasma density by comparing two closely separated spacecraft and thereby reconstructing the uncontrolled potential variation from the controlled potential. Regular intercalibration of controlled and uncontrolled potentials is expected to increase the reliability of this new method.

  6. Propulsion Trade Studies for Spacecraft Swarm Mission Design

    Dono, Andres; Plice, Laura; Mueting, Joel; Conn, Tracie; Ho, Michael

    2018-01-01

    Spacecraft swarms constitute a challenge from an orbital mechanics standpoint. Traditional mission design involves the application of methodical processes where predefined maneuvers for an individual spacecraft are planned in advance. This approach does not scale to spacecraft swarms consisting of many satellites orbiting in close proximity; non-deterministic maneuvers cannot be preplanned due to the large number of units and the uncertainties associated with their differential deployment and orbital motion. For autonomous small sat swarms in LEO, we investigate two approaches for controlling the relative motion of a swarm. The first method involves modified miniature phasing maneuvers, where maneuvers are prescribed that cancel the differential delta V of each CubeSat's deployment vector. The second method relies on artificial potential functions (APFs) to contain the spacecraft within a volumetric boundary and avoid collisions. Performance results and required delta V budgets are summarized, indicating that each method has advantages and drawbacks for particular applications. The mini phasing maneuvers are more predictable and sustainable. The APF approach provides a more responsive and distributed performance, but at considerable propellant cost. After considering current state of the art CubeSat propulsion systems, we conclude that the first approach is feasible, but the modified APF method of requires too much control authority to be enabled by current propulsion systems.

  7. Autonomous spacecraft landing through human pre-attentive vision

    Schiavone, Giuseppina; Izzo, Dario; Simões, Luís F; De Croon, Guido C H E

    2012-01-01

    In this work, we exploit a computational model of human pre-attentive vision to guide the descent of a spacecraft on extraterrestrial bodies. Providing the spacecraft with high degrees of autonomy is a challenge for future space missions. Up to present, major effort in this research field has been concentrated in hazard avoidance algorithms and landmark detection, often by reference to a priori maps, ranked by scientists according to specific scientific criteria. Here, we present a bio-inspired approach based on the human ability to quickly select intrinsically salient targets in the visual scene; this ability is fundamental for fast decision-making processes in unpredictable and unknown circumstances. The proposed system integrates a simple model of the spacecraft and optimality principles which guarantee minimum fuel consumption during the landing procedure; detected salient sites are used for retargeting the spacecraft trajectory, under safety and reachability conditions. We compare the decisions taken by the proposed algorithm with that of a number of human subjects tested under the same conditions. Our results show how the developed algorithm is indistinguishable from the human subjects with respect to areas, occurrence and timing of the retargeting. (paper)

  8. Time-dependent polar distribution of outgassing from a spacecraft

    Scialdone, J. J.

    1974-01-01

    A technique has been developed to obtain a characterization of the self-generated environment of a spacecraft and its variation with time, angular position, and distance. The density, pressure, outgassing flux, total weight loss, and other important parameters were obtained from data provided by two mass measuring crystal microbalances, mounted back to back, at distance of 1 m from the spacecraft equivalent surface. A major outgassing source existed at an angular position of 300 deg to 340 deg, near the rocket motor, while the weakest source was at the antennas. The strongest source appeared to be caused by a material diffusion process which produced a directional density at 1 m distance of about 1.6 x 10 to the 11th power molecules/cu cm after 1 hr in vacuum and decayed to 1.6 x 10 to the 9th power molecules/cu cm after 200 hr. The total average outgassing flux at the same distance and during the same time span changed from 1.2 x 10 to the minus 7th power to 1.4 x to the minus 10th power g/sq cm/s. These values are three times as large at the spacecraft surface. Total weight loss was 537 g after 10 hr and about 833 g after 200 hr. Self-contamination of the spacecraft was equivalent to that in orbit at about 300-km altitude.

  9. Computation Directorate 2008 Annual Report

    Crawford, D L

    2009-03-25

    Whether a computer is simulating the aging and performance of a nuclear weapon, the folding of a protein, or the probability of rainfall over a particular mountain range, the necessary calculations can be enormous. Our computers help researchers answer these and other complex problems, and each new generation of system hardware and software widens the realm of possibilities. Building on Livermore's historical excellence and leadership in high-performance computing, Computation added more than 331 trillion floating-point operations per second (teraFLOPS) of power to LLNL's computer room floors in 2008. In addition, Livermore's next big supercomputer, Sequoia, advanced ever closer to its 2011-2012 delivery date, as architecture plans and the procurement contract were finalized. Hyperion, an advanced technology cluster test bed that teams Livermore with 10 industry leaders, made a big splash when it was announced during Michael Dell's keynote speech at the 2008 Supercomputing Conference. The Wall Street Journal touted Hyperion as a 'bright spot amid turmoil' in the computer industry. Computation continues to measure and improve the costs of operating LLNL's high-performance computing systems by moving hardware support in-house, by measuring causes of outages to apply resources asymmetrically, and by automating most of the account and access authorization and management processes. These improvements enable more dollars to go toward fielding the best supercomputers for science, while operating them at less cost and greater responsiveness to the customers.

  10. 5 CFR 2638.506 - Director's recommendation.

    2010-01-01

    ... of the respondent employee's agency that appropriate disciplinary action be taken. If the respondent..., thereafter, will provide appropriate notice of the disciplinary action taken. (c) Notice of noncompliance. If the Director determines that the head of an agency has not taken appropriate disciplinary action...

  11. 50 CFR 18.91 - Director's decision.

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Director's decision. 18.91 Section 18.91...) TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND... decision. (a) Upon receipt of the recommended decision and transcript and after the thirty-day period for...

  12. Board of directors and risk management

    van der Elst, C.F.; Birkmose, H.; Neville, M.; Sorensen, K.

    2013-01-01

    The board of directors is responsible for an appropriate business risk management environment. The paper studies in a comparative way how legislators and courts fill this duty. We question whether the legislative and regulatory framework will improve the equilibrium between entrepreneurship and risk

  13. Where Is the Next Rose Director?

    John Blundell

    2013-01-01

    Rose Friedman (née Director), the Chicago-trained economist, was a very important contributor to Milton Friedman’s scholarly output, popular writings, and television series. His remarkable role in society was to a significant extent a joint role from which she cannot be separated.

  14. IAEA Director General to Visit Iran

    2013-01-01

    Full text: IAEA Director General Yukiya Amano will travel to Tehran on 10 November 2013 to meet senior Iranian leaders on Monday, 11 November 2013, with the aim of strengthening dialogue and cooperation. Separately, as previously announced, IAEA and Iranian experts will meet in Tehran on Monday to discuss technical issues. IAEA)

  15. Foreword by the director of Bohunice NPPs

    1998-01-01

    In this foreword the director briefly describes activities of the NPP Bohunice in 1997. Main activities were: electric and heat production , the V-1 NPP Gradual Reconstruction Programme, nuclear safety programmes, environment protection, international co-operation as well as national and international public information

  16. Annual review and directors' report and accounts

    1992-07-01

    This annual report of Midlands Electricity PLC (MEB) presents a financial review of the Group and the directors' and auditors reports. Historical and current cost profit and loss accounts, balance sheets and cash flow statements are tabulated. The Group's financial history and regulatory accounts are also presented. (UK)

  17. Directors' report and accounts 1990-1991

    1992-01-01

    The Director's Report and accounts for Scottish Hydro-Electric PLC are presented for the period 1990-91. Details are given of the accounting policies, profit and loss account, balance sheet, source and application of funds and abridged current cost information. (UK)

  18. Summer Principals'/Directors' Orientation Training Module.

    Mata, Robert L.; Garcia, Richard L.

    Intended to provide current or potential project principals/directors with the basic knowledge, skills, abilities, and sensitivities needed to manage a summer migrant school project in the local educational setting, this module provides instruction in the project management areas of planning, preparation, control, and termination. The module…

  19. Board diligence, director business and corporate governance

    Saibal Ghosh

    2007-11-01

    Full Text Available The paper examines the association between financial performance and boards of non-financial firms. Using data on over 200 listed manufacturing firms in India for 2005, the findings indicate that, after controlling for various firm-specific factors, board diligence as well as director busyness exerts a positive influence on corporate performance.

  20. A Director's Guide to High School Horns.

    Conway, Collen

    1998-01-01

    Conveys that the horn (French horn) is the most difficult instrument for band and orchestra directors to teach because playing the horn requires students to have very strong aural skills. Identifies the horn specific techniques students should know, such as hand positions, alternate fingerings, and transposition. Provides different methods for…

  1. 75 FR 56667 - Facilitating Shareholder Director Nominations

    2010-09-16

    ...', nominees for director. We believe that these rules will benefit shareholders by improving corporate suffrage, the disclosure provided in connection with corporate proxy solicitations, and communication... Communications E. Costs 1. Costs Related to Potential Adverse Effects on Company and Board Performance 2. Costs...

  2. 45 CFR 1700.5 - Executive Director.

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Executive Director. 1700.5 Section 1700.5 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL COMMISSION ON LIBRARIES AND..., recommendation and implementation of overall plans and policies to achieve the Commission's goals. (d) To...

  3. VMware vCloud Director essentials

    Pal, Lipika

    2014-01-01

    If you are a technical professional with system administration knowledge, then this book is for you. The book also covers areas of importance if you are a virtualization engineer, consultant, architect, senior system engineer, or senior system analyst. You should possess core vSphere platform knowledge necessary to serve as a base to learn vCloud Director and its associated components.

  4. Enhancing teamwork between chief residents and residency program directors: description and outcomes of an experiential workshop.

    McPhillips, Heather A; Frohna, John G; Murad, M Hassan; Batra, Maneesh; Panda, Mukta; Miller, Marsha A; Brigham, Timothy P; Doughty, Robert A

    2011-12-01

    An effective working relationship between chief residents and residency program directors is critical to a residency program's success. Despite the importance of this relationship, few studies have explored the characteristics of an effective program director-chief resident partnership or how to facilitate collaboration between the 2 roles, which collectively are important to program quality and resident satisfaction. We describe the development and impact of a novel workshop that paired program directors with their incoming chief residents to facilitate improved partnerships. The Accreditation Council for Graduate Medical Education sponsored a full-day workshop for residency program directors and their incoming chief residents. Sessions focused on increased understanding of personality styles, using experiential learning, and open communication between chief residents and program directors, related to feedback and expectations of each other. Participants completed an anonymous survey immediately after the workshop and again 8 months later to assess its long-term impact. Participants found the workshop to be a valuable experience, with comments revealing common themes. Program directors and chief residents expect each other to act as a role model for the residents, be approachable and available, and to be transparent and fair in their decision-making processes; both groups wanted feedback on performance and clear expectations from each other for roles and responsibilities; and both groups identified the need to be innovative and supportive of changes in the program. Respondents to the follow-up survey reported that workshop participation improved their relationships with their co-chiefs and program directors. Participation in this experiential workshop improved the working relationships between chief residents and program directors. The themes that were identified can be used to foster communication between incoming chief residents and residency directors and to

  5. IAEA Director General to visit Libya

    2003-01-01

    reverse course is a positive development and a step in the right direction. I hope that through verification, dialogue and active engagement, all questions related to Libya's nuclear programme can be resolved and the required corrective actions taken.' The Director General added, 'This latest revelation confirms the need, in parallel with the peace process in the Middle East, for a security dialogue that aims to establish as part and parcel of the peace settlement a sustainable security structure that inter alia turns the Middle East into a zone free from nuclear and other weapons of mass destruction.' (IAEA)

  6. A Sampling Based Approach to Spacecraft Autonomous Maneuvering with Safety Specifications

    Starek, Joseph A.; Barbee, Brent W.; Pavone, Marco

    2015-01-01

    This paper presents a methods for safe spacecraft autonomous maneuvering that leverages robotic motion-planning techniques to spacecraft control. Specifically the scenario we consider is an in-plan rendezvous of a chaser spacecraft in proximity to a target spacecraft at the origin of the Clohessy Wiltshire Hill frame. The trajectory for the chaser spacecraft is generated in a receding horizon fashion by executing a sampling based robotic motion planning algorithm name Fast Marching Trees (FMT) which efficiently grows a tree of trajectories over a set of probabillistically drawn samples in the state space. To enforce safety the tree is only grown over actively safe samples for which there exists a one-burn collision avoidance maneuver that circularizes the spacecraft orbit along a collision-free coasting arc and that can be executed under potential thrusters failures. The overall approach establishes a provably correct framework for the systematic encoding of safety specifications into the spacecraft trajectory generations process and appears amenable to real time implementation on orbit. Simulation results are presented for a two-fault tolerant spacecraft during autonomous approach to a single client in Low Earth Orbit.

  7. The mechanical design and dynamic testing of the IBEX-H1 electrostatic analyzer spacecraft instrument

    Bernardin, John D [Los Alamos National Laboratory; Baca, Allen G [SNL

    2009-01-01

    This paper presents the mechanical design, fabrication and dynamic testing of an electrostatic analyzer spacecraft instrument. The functional and environmental requirements combined with limited spacecraft accommodations, resulted in complex component geometries, unique material selections, and difficult fabrication processes. The challenging aspects of the mechanical design and several of the more difficult production processes are discussed. In addition, the successes, failures, and lessons learned from acoustic and random vibration testing of a full-scale prototype instrument are presented.

  8. Foot Pedals for Spacecraft Manual Control

    Love, Stanley G.; Morin, Lee M.; McCabe, Mary

    2010-01-01

    Fifty years ago, NASA decided that the cockpit controls in spacecraft should be like the ones in airplanes. But controls based on the stick and rudder may not be best way to manually control a vehicle in space. A different method is based on submersible vehicles controlled with foot pedals. A new pilot can learn the sub's control scheme in minutes and drive it hands-free. We are building a pair of foot pedals for spacecraft control, and will test them in a spacecraft flight simulator.

  9. Technical report.Technical advise to the DINAMIGE ( Mining and Energy Directorate) Montevideo - Uruguay in relation to the environment impact which could originate the installation of gold mineral processing plants

    Piret, N.; Shoukry, B.

    1990-01-01

    In 1990 Dinamige was assisted by a German mission in relation to the environment impact which could originate the installation of mineral of oro processing plants. This study were carried out in two priority zones: Project Mahoma by the Mining San Jose Co. S.A/Retamosa SRL in San Jose district /Stel S.A in Minas de Corrales in Rivera.

  10. Distributed Autonomous Control of Multiple Spacecraft During Close Proximity Operations

    McCamish, Shawn B

    2007-01-01

    This research contributes to multiple spacecraft control by developing an autonomous distributed control algorithm for close proximity operations of multiple spacecraft systems, including rendezvous...

  11. Spacecraft Swarm Coordination and Planning Tool, Phase I

    National Aeronautics and Space Administration — Fractionated spacecraft architectures to distribute mission performance from a single, monolithic satellite across large number of smaller spacecraft, for missions...

  12. Spacecraft Cabin Particulate Monitor, Phase II

    National Aeronautics and Space Administration — We have built and tested an optical extinction monitor for the detection of spacecraft cabin particulates. This sensor sensitive to particle sizes ranging from a few...

  13. SSTI- Lewis Spacecraft Nickel-Hydrogen Battery

    Tobias, R. F.

    1997-01-01

    Topics considered include: NASA-Small Spacecraft Technology Initiative (SSTI) objectives, SSTI-Lewis overview, battery requirement, two cells Common Pressure Vessel (CPV) design summary, CPV electric performance, battery design summary, battery functional description, battery performance.

  14. Spacecraft Cabin Particulate Monitor, Phase I

    National Aeronautics and Space Administration — We propose to design, build and test an optical extinction monitor for the detection of spacecraft cabin particulates. This monitor will be sensitive to particle...

  15. Automated constraint checking of spacecraft command sequences

    Horvath, Joan C.; Alkalaj, Leon J.; Schneider, Karl M.; Spitale, Joseph M.; Le, Dang

    1995-01-01

    Robotic spacecraft are controlled by onboard sets of commands called "sequences." Determining that sequences will have the desired effect on the spacecraft can be expensive in terms of both labor and computer coding time, with different particular costs for different types of spacecraft. Specification languages and appropriate user interface to the languages can be used to make the most effective use of engineering validation time. This paper describes one specification and verification environment ("SAVE") designed for validating that command sequences have not violated any flight rules. This SAVE system was subsequently adapted for flight use on the TOPEX/Poseidon spacecraft. The relationship of this work to rule-based artificial intelligence and to other specification techniques is discussed, as well as the issues that arise in the transfer of technology from a research prototype to a full flight system.

  16. Computational Model for Spacecraft/Habitat Volume

    National Aeronautics and Space Administration — Please note that funding to Dr. Simon Hsiang, a critical co-investigator for the development of the Spacecraft Optimization Layout and Volume (SOLV) model, was...

  17. Spacecraft Multiple Array Communication System Performance Analysis

    Hwu, Shian U.; Desilva, Kanishka; Sham, Catherine C.

    2010-01-01

    The Communication Systems Simulation Laboratory (CSSL) at the NASA Johnson Space Center is tasked to perform spacecraft and ground network communication system simulations, design validation, and performance verification. The CSSL has developed simulation tools that model spacecraft communication systems and the space and ground environment in which the tools operate. In this paper, a spacecraft communication system with multiple arrays is simulated. Multiple array combined technique is used to increase the radio frequency coverage and data rate performance. The technique is to achieve phase coherence among the phased arrays to combine the signals at the targeting receiver constructively. There are many technical challenges in spacecraft integration with a high transmit power communication system. The array combining technique can improve the communication system data rate and coverage performances without increasing the system transmit power requirements. Example simulation results indicate significant performance improvement can be achieved with phase coherence implementation.

  18. Formation of disintegration particles in spacecraft recorders

    Kurnosova, L.V.; Fradkin, M.I.; Razorenov, L.A.

    1986-01-01

    Experiments performed on the spacecraft Salyut 1, Kosmos 410, and Kosmos 443 enable us to record the disintegration products of particles which are formed in the material of the detectors on board the spacecraft. The observations were made by means of a delayed coincidence method. We have detected a meson component and also a component which is apparently associated with the generation of radioactive isotopes in the detectors

  19. Power requirements for commercial communications spacecraft

    Billerbeck, W. J.

    1985-01-01

    Historical data on commercial spacecraft power systems are presented and their power requirements to the growth of satellite communications channel usage are related. Some approaches for estimating future power requirements of this class of spacecraft through the year 2000 are proposed. The key technology drivers in satellite power systems are addressed. Several technological trends in such systems are described, focusing on the most useful areas for research and development of major subsystems, including solar arrays, energy storage, and power electronics equipment.

  20. A Reconfigurable Testbed Environment for Spacecraft Autonomy

    Biesiadecki, Jeffrey; Jain, Abhinandan

    1996-01-01

    A key goal of NASA's New Millennium Program is the development of technology for increased spacecraft on-board autonomy. Achievement of this objective requires the development of a new class of ground-based automony testbeds that can enable the low-cost and rapid design, test, and integration of the spacecraft autonomy software. This paper describes the development of an Autonomy Testbed Environment (ATBE) for the NMP Deep Space I comet/asteroid rendezvous mission.

  1. Radioisotopic heater units warm an interplanetary spacecraft

    Franco-Ferreira, E.A.

    1998-01-01

    The Cassini orbiter and Huygens probe, which were successfully launched on October 15, 1997, constitute NASA's last grand-scale interplanetary mission of this century. The mission, which consists of a four-year, close-up study of Saturn and its moons, begins in July 2004 with Cassini's 60 orbits of Saturn and about 33 fly-bys of the large moon Titan. The Huygens probe will descend and land on Titan. Investigations will include Saturn's atmosphere, its rings and its magnetosphere. The atmosphere and surface of Titan and other icy moons also will be characterized. Because of the great distance of Saturn from the sun, some of the instruments and equipment on both the orbiter and the probe require external heaters to maintain their temperature within normal operating ranges. These requirements are met by Light Weight Radioisotope Heater Units (LWRHUs) designed, fabricated and safety tested at Los Alamos National Laboratory, New Mexico. An improved gas tungsten arc welding procedure lowered costs and decreased processing time for heat units for the Cassini spacecraft

  2. An AFDX Network for Spacecraft Data Handling

    Deredempt, Marie-Helene; Kollias, Vangelis; Sun, Zhili; Canamares, Ernest; Ricco, Philippe

    2014-08-01

    In aeronautical domain, ARINC-664 Part 7 specification (AFDX) [4] provides the enabling technology for interfacing equipment in Integrated Modular Avionics (IMA) architectures. The complementary part of AFDX for a complete interoperability - Time and Space Partitioning (ARINC 653) concepts [1]- was already studied as part of space domain ESA roadmap (i.e. IMA4Space project)Standardized IMA based architecture is already considered in aeronautical domain as more flexible, reliable and secure. Integration and validation become simple, using a common set of tools and data base and could be done by part on different means with the same definition (hardware and software test benches, flight control or alarm test benches, simulator and flight test installation).In some area, requirements in terms of data processing are quite similar in space domain and the concept could be applicable to take benefit of the technology itself and of the panel of hardware and software solutions and tools available on the market. The Mission project (Methodology and assessment for the applicability of ARINC-664 (AFDX) in Satellite/Spacecraft on-board communicatION networks), as an FP7 initiative for bringing terrestrial SME research into the space domain started to evaluate the applicability of the standard in space domain.

  3. NASA Medical Response to Human Spacecraft Accidents

    Patlach, Robert

    2011-01-01

    This slide presentation reviews NASA's role in the response to spacecraft accidents that involve human fatalities or injuries. Particular attention is given to the work of the Mishap Investigation Team (MIT), the first response to the accidents and the interface to the accident investigation board. The MIT does not investigate the accident, but the objective of the MIT is to gather, guard, preserve and document the evidence. The primary medical objectives of the MIT is to receive, analyze, identify, and transport human remains, provide assistance in the recovery effort, and to provide family Casualty Coordinators with latest recovery information. The MIT while it does not determine the cause of the accident, it acts as the fact gathering arm of the Mishap Investigation Board (MIB), which when it is activated may chose to continue to use the MIT as its field investigation resource. The MIT membership and the specific responsibilities and tasks of the flight surgeon is reviewed. The current law establishing the process is also reviewed.

  4. Radiation Effects on Spacecraft Structural Materials

    Wang, Jy-An J.; Ellis, Ronald J.; Hunter, Hamilton T.; Singleterry, Robert C. Jr.

    2002-01-01

    Research is being conducted to develop an integrated technology for the prediction of aging behavior for space structural materials during service. This research will utilize state-of-the-art radiation experimental apparatus and analysis, updated codes and databases, and integrated mechanical and radiation testing techniques to investigate the suitability of numerous current and potential spacecraft structural materials. Also included are the effects on structural materials in surface modules and planetary landing craft, with or without fission power supplies. Spacecraft structural materials would also be in hostile radiation environments on the surface of the moon and planets without appreciable atmospheres and moons around planets with large intense magnetic and radiation fields (such as the Jovian moons). The effects of extreme temperature cycles in such locations compounds the effects of radiation on structural materials. This paper describes the integrated methodology in detail and shows that it will provide a significant technological advance for designing advanced spacecraft. This methodology will also allow for the development of advanced spacecraft materials through the understanding of the underlying mechanisms of material degradation in the space radiation environment. Thus, this technology holds a promise for revolutionary advances in material damage prediction and protection of space structural components as, for example, in the development of guidelines for managing surveillance programs regarding the integrity of spacecraft components, and the safety of the aging spacecraft. (authors)

  5. Standardizing the information architecture for spacecraft operations

    Easton, C. R.

    1994-01-01

    This paper presents an information architecture developed for the Space Station Freedom as a model from which to derive an information architecture standard for advanced spacecraft. The information architecture provides a way of making information available across a program, and among programs, assuming that the information will be in a variety of local formats, structures and representations. It provides a format that can be expanded to define all of the physical and logical elements that make up a program, add definitions as required, and import definitions from prior programs to a new program. It allows a spacecraft and its control center to work in different representations and formats, with the potential for supporting existing spacecraft from new control centers. It supports a common view of data and control of all spacecraft, regardless of their own internal view of their data and control characteristics, and of their communications standards, protocols and formats. This information architecture is central to standardizing spacecraft operations, in that it provides a basis for information transfer and translation, such that diverse spacecraft can be monitored and controlled in a common way.

  6. Attitude Estimation in Fractionated Spacecraft Cluster Systems

    Hadaegh, Fred Y.; Blackmore, James C.

    2011-01-01

    An attitude estimation was examined in fractioned free-flying spacecraft. Instead of a single, monolithic spacecraft, a fractionated free-flying spacecraft uses multiple spacecraft modules. These modules are connected only through wireless communication links and, potentially, wireless power links. The key advantage of this concept is the ability to respond to uncertainty. For example, if a single spacecraft module in the cluster fails, a new one can be launched at a lower cost and risk than would be incurred with onorbit servicing or replacement of the monolithic spacecraft. In order to create such a system, however, it is essential to know what the navigation capabilities of the fractionated system are as a function of the capabilities of the individual modules, and to have an algorithm that can perform estimation of the attitudes and relative positions of the modules with fractionated sensing capabilities. Looking specifically at fractionated attitude estimation with startrackers and optical relative attitude sensors, a set of mathematical tools has been developed that specify the set of sensors necessary to ensure that the attitude of the entire cluster ( cluster attitude ) can be observed. Also developed was a navigation filter that can estimate the cluster attitude if these conditions are satisfied. Each module in the cluster may have either a startracker, a relative attitude sensor, or both. An extended Kalman filter can be used to estimate the attitude of all modules. A range of estimation performances can be achieved depending on the sensors used and the topology of the sensing network.

  7. OTA director to be Clinton's science advisor

    Leath, Audrey

    President Clinton has nominated John H. “Jack” Gibbons to be Assistant to the President for Science and Technology, and director of the White House Office of Science and Technology Policy (OSTP). For over a decade, Gibbons has served as director of the Office of Technology Assessment (OTA), a bipartisan research arm of Congress.In nominating Gibbons, Clinton said, “I am delighted to appoint a brilliant scientist and gifted administrator… It is profoundly important that the president have a science advisor who understands science, who understands technology, who understands the practical application of these disciplines to the myriad of problems we face today. And I can tell you that from [Vice-president] Al Gore on down to every other member of Congress I have discussed John Gibbons with, I have hardly ever received more glowing and more consistent recommendations for anyone.”

  8. What competencies should directors possess? Malaysia perspective

    Wan Fauziah Wan Yusoff

    2011-07-01

    Full Text Available Directors’ competencies are seeing to be of importance to corporate governance. As this issue has not yet being studied extensively in Malaysia, this study determines the key competencies of Malaysian company’s directors using qualitative approach involving two stages of Delphi Technique. In the first stage all information pertaining to directors’ competences in the literature had been reviewed. In the second stage, the key competencies identified in stage one were the criteria for developing a semi structured questionnaire. Participants were asked to rank the competencies in term of their importance for directors’ performance. Based on personel interviews with 41 participants eight types of competencies were found to be essential for Malaysian companies’ directors. Financial competencies received the highest responses, followed by corporate planning, business forecasting, legal, risk management, marketing, human resource and international business. This paper provides important evidence to support the conclusions drawn from the study about the importance of relevant directors’ competencies for board and corporate effectiveness.

  9. IAEA Director General welcomes NPT consensus

    2000-01-01

    The document informs that the Director General of the IAEA welcomed the adoption with consensus by the Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons of the final document on the review and operation of the Treaty, and that he was pleased by the vote of confidence shown in the IAEA and its role in the implementation of the Treaty

  10. OSG Director reports on grid progress

    Pordes, Ruth

    2006-01-01

    "In this Q&A from the Open Science Grid (OSG), executive director Ruth Prodes provides a brief history of the OSG, an overview of current projects and partners, and a glimpse at future plans, including how the recent $30 million award from the ODE's office of Science and the NSF will be employed. She also shares her thoughts of SC, saying the personal contacts are the best part."(4,5 pages)

  11. Diversity of what? Multifaceted Boards and Directors

    A. Hillman; S. Nielsen; A. Zattoni

    2012-01-01

    Board diversity has long intrigued practitioners and scholars. Constituents encourage companies to vary of director characteristics, but companies often resist. Academics debate whether diversity is beneficial for board decision-making and the empirical evidence is mixed, partly because “diversity” is treated as a singular construct despite representing many different forms (e.g. demographic, human capital and social capital). We propose a theoretical model of board diversit...

  12. UNC Cancer Center Director to Lead NCI.

    2017-08-01

    President Donald Trump has selected Norman "Ned" Sharpless, MD, director of the University of North Carolina Lineberger Comprehensive Cancer Center, to lead the NCI. The news was met with widespread approval among cancer researchers, who view Sharpless as a strong communicator who can ably represent the needs of the cancer community in the face of proposed funding cuts. ©2017 American Association for Cancer Research.

  13. Results from the NASA Spacecraft Fault Management Workshop: Cost Drivers for Deep Space Missions

    Newhouse, Marilyn E.; McDougal, John; Barley, Bryan; Stephens Karen; Fesq, Lorraine M.

    2010-01-01

    Fault Management, the detection of and response to in-flight anomalies, is a critical aspect of deep-space missions. Fault management capabilities are commonly distributed across flight and ground subsystems, impacting hardware, software, and mission operations designs. The National Aeronautics and Space Administration (NASA) Discovery & New Frontiers (D&NF) Program Office at Marshall Space Flight Center (MSFC) recently studied cost overruns and schedule delays for five missions. The goal was to identify the underlying causes for the overruns and delays, and to develop practical mitigations to assist the D&NF projects in identifying potential risks and controlling the associated impacts to proposed mission costs and schedules. The study found that four out of the five missions studied had significant overruns due to underestimating the complexity and support requirements for fault management. As a result of this and other recent experiences, the NASA Science Mission Directorate (SMD) Planetary Science Division (PSD) commissioned a workshop to bring together invited participants across government, industry, and academia to assess the state of the art in fault management practice and research, identify current and potential issues, and make recommendations for addressing these issues. The workshop was held in New Orleans in April of 2008. The workshop concluded that fault management is not being limited by technology, but rather by a lack of emphasis and discipline in both the engineering and programmatic dimensions. Some of the areas cited in the findings include different, conflicting, and changing institutional goals and risk postures; unclear ownership of end-to-end fault management engineering; inadequate understanding of the impact of mission-level requirements on fault management complexity; and practices, processes, and tools that have not kept pace with the increasing complexity of mission requirements and spacecraft systems. This paper summarizes the

  14. Emotional intelligence model for directors of research centers in mexico

    Mara Maricela Trujillo Flores

    2008-01-01

    H5 Social skills exhibited by directors, that are also part of interpersonal intelligence, allow a director to exert a greater influence on the working group, facilitating communication, conflict management, leadership, collaboration, cooperation and development of team skills.

  15. Large-Scale Spacecraft Fire Safety Tests

    Urban, David; Ruff, Gary A.; Ferkul, Paul V.; Olson, Sandra; Fernandez-Pello, A. Carlos; T'ien, James S.; Torero, Jose L.; Cowlard, Adam J.; Rouvreau, Sebastien; Minster, Olivier; hide

    2014-01-01

    An international collaborative program is underway to address open issues in spacecraft fire safety. Because of limited access to long-term low-gravity conditions and the small volume generally allotted for these experiments, there have been relatively few experiments that directly study spacecraft fire safety under low-gravity conditions. Furthermore, none of these experiments have studied sample sizes and environment conditions typical of those expected in a spacecraft fire. The major constraint has been the size of the sample, with prior experiments limited to samples of the order of 10 cm in length and width or smaller. This lack of experimental data forces spacecraft designers to base their designs and safety precautions on 1-g understanding of flame spread, fire detection, and suppression. However, low-gravity combustion research has demonstrated substantial differences in flame behavior in low-gravity. This, combined with the differences caused by the confined spacecraft environment, necessitates practical scale spacecraft fire safety research to mitigate risks for future space missions. To address this issue, a large-scale spacecraft fire experiment is under development by NASA and an international team of investigators. This poster presents the objectives, status, and concept of this collaborative international project (Saffire). The project plan is to conduct fire safety experiments on three sequential flights of an unmanned ISS re-supply spacecraft (the Orbital Cygnus vehicle) after they have completed their delivery of cargo to the ISS and have begun their return journeys to earth. On two flights (Saffire-1 and Saffire-3), the experiment will consist of a flame spread test involving a meter-scale sample ignited in the pressurized volume of the spacecraft and allowed to burn to completion while measurements are made. On one of the flights (Saffire-2), 9 smaller (5 x 30 cm) samples will be tested to evaluate NASAs material flammability screening tests

  16. Relating MBSE to Spacecraft Development: A NASA Pathfinder

    Othon, Bill

    2016-01-01

    The NASA Engineering and Safety Center (NESC) has sponsored a Pathfinder Study to investigate how Model Based Systems Engineering (MBSE) and Model Based Engineering (MBE) techniques can be applied by NASA spacecraft development projects. The objectives of this Pathfinder Study included analyzing both the products of the modeling activity, as well as the process and tool chain through which the spacecraft design activities are executed. Several aspects of MBSE methodology and process were explored. Adoption and consistent use of the MBSE methodology within an existing development environment can be difficult. The Pathfinder Team evaluated the possibility that an "MBSE Template" could be developed as both a teaching tool as well as a baseline from which future NASA projects could leverage. Elements of this template include spacecraft system component libraries, data dictionaries and ontology specifications, as well as software services that do work on the models themselves. The Pathfinder Study also evaluated the tool chain aspects of development. Two chains were considered: 1. The Development tool chain, through which SysML model development was performed and controlled, and 2. The Analysis tool chain, through which both static and dynamic system analysis is performed. Of particular interest was the ability to exchange data between SysML and other engineering tools such as CAD and Dynamic Simulation tools. For this study, the team selected a Mars Lander vehicle as the element to be designed. The paper will discuss what system models were developed, how data was captured and exchanged, and what analyses were conducted.

  17. Customizing graphical user interface technology for spacecraft control centers

    Beach, Edward; Giancola, Peter; Gibson, Steven; Mahmot, Ronald

    1993-01-01

    The Transportable Payload Operations Control Center (TPOCC) project is applying the latest in graphical user interface technology to the spacecraft control center environment. This project of the Mission Operations Division's (MOD) Control Center Systems Branch (CCSB) at NASA Goddard Space Flight Center (GSFC) has developed an architecture for control centers which makes use of a distributed processing approach and the latest in Unix workstation technology. The TPOCC project is committed to following industry standards and using commercial off-the-shelf (COTS) hardware and software components wherever possible to reduce development costs and to improve operational support. TPOCC's most successful use of commercial software products and standards has been in the development of its graphical user interface. This paper describes TPOCC's successful use and customization of four separate layers of commercial software products to create a flexible and powerful user interface that is uniquely suited to spacecraft monitoring and control.

  18. A solar cycle of spacecraft anomalies due to internal charging

    G. L. Wrenn

    Full Text Available It is important to appreciate how the morphology of internal charging of spacecraft systems, due to penetrating electrons, differs from that of the more common surface charging, due to electrons with lower energy. A specific and recurrent anomaly on a geostationary communication satellite has been tracked for ten years so that solar cycle and seasonal dependencies can be clearly established. Concurrent measurements of sunspot number, solar wind speed and 2-day >2 MeV electron fluence are presented to highlight pertinent space weather relationships, and the importance of understanding the complex particle interaction processes involved.

    Key words. Magnetospheric physics (energetic particles; trapped; solar wind – magnetosphere interactions – space plasma physics (spacecraft sheaths, wakes, charging

  19. A solar cycle of spacecraft anomalies due to internal charging

    G. L. Wrenn

    2002-07-01

    Full Text Available It is important to appreciate how the morphology of internal charging of spacecraft systems, due to penetrating electrons, differs from that of the more common surface charging, due to electrons with lower energy. A specific and recurrent anomaly on a geostationary communication satellite has been tracked for ten years so that solar cycle and seasonal dependencies can be clearly established. Concurrent measurements of sunspot number, solar wind speed and 2-day >2 MeV electron fluence are presented to highlight pertinent space weather relationships, and the importance of understanding the complex particle interaction processes involved.Key words. Magnetospheric physics (energetic particles; trapped; solar wind – magnetosphere interactions – space plasma physics (spacecraft sheaths, wakes, charging

  20. Press briefing on results from the solar spacecraft SOHO

    1998-04-01

    After its launch on 2 December 1995, SOHO travelled to take up a special orbit 1.5 million kilometres away on the sunward side of the Earth, where the Sun never sets. The full scientific programme began in April 1996. The occasion for the briefing is the celebration of that second anniversary and of the mission's extension to 2003. Organized by the European Space Agency, the briefing will be hosted by the Rutherford Appleton Laboratory, which is near Oxford. Leading scientists associated with SOHO will announce to the press some remarkable new discoveries about the Sun's interior, atmosphere and solar wind. They will also briefly review the main achievements of the past two years. The role of SOHO as the chief watchdog for storms on the Sun that may affect the Earth will be demonstrated. Europe's creation of the finest spacecraft ever built to observe the Sun will be recalled by a top engineer from ESA. A speaker from NASA will explain transatlantic contributions to SOHO, which is a project of international cooperation between ESA and NASA. ESA's director of science will also be present, to relate SOHO to ESA's general science programme. A lunch-time talk by the BNSC's director of science completes the line-up of speakers. This is also an exceptional opportunity for the press to meet and interview scientists from all over Europe and the USA, who are attending a meeting at the Rutherford Appleton Laboratory of SOHO's Science Working Team (SWT). Journalists are usually excluded from such meetings. The Rutherford Appleton Laboratory plays a prominent part in SOHO, particularly through its provision of the CDS ultraviolet spectrometer. A visit to the CDS group will provide a chance to see what space research is really like. Please indicate your intention to attend, on the accreditation form that follows the schedule. Guidance on how to get to the Rutherford Appleton Laboratory is appended. PROGRAMME Rutherford Appleton Laboratory (RAL), 28 April 1998 10:30 Assembly of

  1. NASA Mission Operations Directorate Preparations for the COTS Visiting Vehicles

    Shull, Sarah A.; Peek, Kenneth E.

    2011-01-01

    With the retirement of the Space Shuttle looming, a series of new spacecraft is under development to assist in providing for the growing logistical needs of the International Space Station (ISS). Two of these vehicles are being built under a NASA initiative known as the Commercial Orbital Transportation Services (COTS) program. These visiting vehicles ; Space X s Dragon and Orbital Science Corporation s Cygnus , are to be domestically produced in the United States and designed to add to the capabilities of the Russian Progress and Soyuz workhorses, the European Automated Transfer Vehicle (ATV) and the Japanese H-2 Transfer Vehicle (HTV). Most of what is known about the COTS program has focused on the work of Orbital and SpaceX in designing, building, and testing their respective launch and cargo vehicles. However, there is also a team within the Mission Operations Directorate (MOD) at NASA s Johnson Space Center working with their operational counterparts in these companies to provide operational safety oversight and mission assurance via the development of operational scenarios and products needed for these missions. Ensuring that the operational aspect is addressed for the initial demonstration flights of these vehicles is the topic of this paper. Integrating Dragon and Cygnus into the ISS operational environment has posed a unique challenge to NASA and their partner companies. This is due in part to the short time span of the COTS program, as measured from initial contract award until first launch, as well as other factors that will be explored in the text. Operational scenarios and products developed for each COTS vehicle will be discussed based on the following categories: timelines, on-orbit checkout, ground documentation, crew procedures, software updates and training materials. Also addressed is an outline of the commonalities associated with the operations for each vehicle. It is the intent of the authors to provide their audience with a better

  2. REQUIREMENTS FOR IMAGE QUALITY OF EMERGENCY SPACECRAFTS

    A. I. Altukhov

    2015-05-01

    Full Text Available The paper deals with the method for formation of quality requirements to the images of emergency spacecrafts. The images are obtained by means of remote sensing of near-earth space orbital deployment in the visible range. of electromagnetic radiation. The method is based on a joint taking into account conditions of space survey, characteristics of surveillance equipment, main design features of the observed spacecrafts and orbital inspection tasks. Method. Quality score is the predicted linear resolution image that gives the possibility to create a complete view of pictorial properties of the space image obtained by electro-optical system from the observing satellite. Formulation of requirements to the numerical value of this indicator is proposed to perform based on the properties of remote sensing system, forming images in the conditions of outer space, and the properties of the observed emergency spacecraft: dimensions, platform construction of the satellite, on-board equipment placement. For method implementation the authors have developed a predictive model of requirements to a linear resolution for images of emergency spacecrafts, making it possible to select the intervals of space shooting and get the satellite images required for quality interpretation. Main results. To verify the proposed model functionality we have carried out calculations of the numerical values for the linear resolution of the image, ensuring the successful task of determining the gross structural damage of the spacecrafts and identifying changes in their spatial orientation. As input data were used with dimensions and geometric primitives corresponding to the shape of deemed inspected spacecrafts: Resurs-P", "Canopus-B", "Electro-L". Numerical values of the linear resolution images have been obtained, ensuring the successful task solution for determining the gross structural damage of spacecrafts.

  3. 12 CFR 918.2 - Annual directors' compensation policy.

    2010-01-01

    ... § 918.3. At a minimum, such policy shall address the activities or functions for which attendance is... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Annual directors' compensation policy. 918.2... HOME LOAN BANKS BANK DIRECTOR COMPENSATION AND EXPENSES § 918.2 Annual directors' compensation policy...

  4. 7 CFR 2.95 - Director, Office of Ethics.

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Director, Office of Ethics. 2.95 Section 2.95... Administration § 2.95 Director, Office of Ethics. The Director, Office of Ethics, shall be the USDA Alternate Agency Ethics Official, pursuant to 5 CFR 2638.202, and shall exercise the authority reserved to the...

  5. Weerts to lead Physical Sciences and Engineering directorate | Argonne

    Physical Sciences and Engineering directorate By Lynn Tefft Hoff * August 10, 2015 Tweet EmailPrint Hendrik Engineering (PSE) directorate at the U.S. Department of Energy's Argonne National Laboratory. Weerts has , chemistry, materials science and nanotechnology. Weerts joined Argonne in 2005 as director of Argonne's High

  6. Health Risks Faced by Public School Band Directors

    Woolery, Danielle N.; Woolery, Jesse A.

    2013-01-01

    Public school band directors face many work-related hazards in their grueling, yet rewarding job. As a school year progresses, directors are expected to work long hours, while trying to balance professional and personal responsibilities. A band director whose career spans multiple decades can potentially face a number of serious medical problems.…

  7. 30 CFR 732.11 - Review by the Director.

    2010-07-01

    ... proposed State program, the Director shall publish in the Federal Register and in a newspaper of general... determined by the Director and published in the Federal Register notice required by paragraph (a). (2) When... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Review by the Director. 732.11 Section 732.11...

  8. Performance Testing of a Photocatalytic Oxidation Module for Spacecraft Cabin Atmosphere Revitalization

    Perry, Jay L.; Abney, Morgan B.; Frederick, Kenneth R.; Scott, Joseph P.; Kaiser, Mark; Seminara, Gary; Bershitsky, Alex

    2011-01-01

    Photocatalytic oxidation (PCO) is a candidate process technology for use in high volumetric flow rate trace contaminant control applications in sealed environments. The targeted application for PCO as applied to crewed spacecraft life support system architectures is summarized. Technical challenges characteristic of PCO are considered. Performance testing of a breadboard PCO reactor design for mineralizing polar organic compounds in a spacecraft cabin atmosphere is described. Test results are analyzed and compared to results reported in the literature for comparable PCO reactor designs.

  9. Robust Spacecraft Component Detection in Point Clouds

    Quanmao Wei

    2018-03-01

    Full Text Available Automatic component detection of spacecraft can assist in on-orbit operation and space situational awareness. Spacecraft are generally composed of solar panels and cuboidal or cylindrical modules. These components can be simply represented by geometric primitives like plane, cuboid and cylinder. Based on this prior, we propose a robust automatic detection scheme to automatically detect such basic components of spacecraft in three-dimensional (3D point clouds. In the proposed scheme, cylinders are first detected in the iteration of the energy-based geometric model fitting and cylinder parameter estimation. Then, planes are detected by Hough transform and further described as bounded patches with their minimum bounding rectangles. Finally, the cuboids are detected with pair-wise geometry relations from the detected patches. After successive detection of cylinders, planar patches and cuboids, a mid-level geometry representation of the spacecraft can be delivered. We tested the proposed component detection scheme on spacecraft 3D point clouds synthesized by computer-aided design (CAD models and those recovered by image-based reconstruction, respectively. Experimental results illustrate that the proposed scheme can detect the basic geometric components effectively and has fine robustness against noise and point distribution density.

  10. Robust Spacecraft Component Detection in Point Clouds.

    Wei, Quanmao; Jiang, Zhiguo; Zhang, Haopeng

    2018-03-21

    Automatic component detection of spacecraft can assist in on-orbit operation and space situational awareness. Spacecraft are generally composed of solar panels and cuboidal or cylindrical modules. These components can be simply represented by geometric primitives like plane, cuboid and cylinder. Based on this prior, we propose a robust automatic detection scheme to automatically detect such basic components of spacecraft in three-dimensional (3D) point clouds. In the proposed scheme, cylinders are first detected in the iteration of the energy-based geometric model fitting and cylinder parameter estimation. Then, planes are detected by Hough transform and further described as bounded patches with their minimum bounding rectangles. Finally, the cuboids are detected with pair-wise geometry relations from the detected patches. After successive detection of cylinders, planar patches and cuboids, a mid-level geometry representation of the spacecraft can be delivered. We tested the proposed component detection scheme on spacecraft 3D point clouds synthesized by computer-aided design (CAD) models and those recovered by image-based reconstruction, respectively. Experimental results illustrate that the proposed scheme can detect the basic geometric components effectively and has fine robustness against noise and point distribution density.

  11. Attitude coordination for spacecraft formation with multiple communication delays

    Guo Yaohua

    2015-04-01

    Full Text Available Communication delays are inherently present in information exchange between spacecraft and have an effect on the control performance of spacecraft formation. In this work, attitude coordination control of spacecraft formation is addressed, which is in the presence of multiple communication delays between spacecraft. Virtual system-based approach is utilized in case that a constant reference attitude is available to only a part of the spacecraft. The feedback from the virtual systems to the spacecraft formation is introduced to maintain the formation. Using backstepping control method, input torque of each spacecraft is designed such that the attitude of each spacecraft converges asymptotically to the states of its corresponding virtual system. Furthermore, the backstepping technique and the Lyapunov–Krasovskii method contribute to the control law design when the reference attitude is time-varying and can be obtained by each spacecraft. Finally, effectiveness of the proposed methodology is illustrated by the numerical simulations of a spacecraft formation.

  12. Artificial Neural Network Based Mission Planning Mechanism for Spacecraft

    Li, Zhaoyu; Xu, Rui; Cui, Pingyuan; Zhu, Shengying

    2018-04-01

    The ability to plan and react fast in dynamic space environments is central to intelligent behavior of spacecraft. For space and robotic applications, many planners have been used. But it is difficult to encode the domain knowledge and directly use existing techniques such as heuristic to improve the performance of the application systems. Therefore, regarding planning as an advanced control problem, this paper first proposes an autonomous mission planning and action selection mechanism through a multiple layer perceptron neural network approach to select actions in planning process and improve efficiency. To prove the availability and effectiveness, we use autonomous mission planning problems of the spacecraft, which is a sophisticated system with complex subsystems and constraints as an example. Simulation results have shown that artificial neural networks (ANNs) are usable for planning problems. Compared with the existing planning method in EUROPA, the mechanism using ANNs is more efficient and can guarantee stable performance. Therefore, the mechanism proposed in this paper is more suitable for planning problems of spacecraft that require real time and stability.

  13. Adaptive Management of Computing and Network Resources for Spacecraft Systems

    Pfarr, Barbara; Welch, Lonnie R.; Detter, Ryan; Tjaden, Brett; Huh, Eui-Nam; Szczur, Martha R. (Technical Monitor)

    2000-01-01

    It is likely that NASA's future spacecraft systems will consist of distributed processes which will handle dynamically varying workloads in response to perceived scientific events, the spacecraft environment, spacecraft anomalies and user commands. Since all situations and possible uses of sensors cannot be anticipated during pre-deployment phases, an approach for dynamically adapting the allocation of distributed computational and communication resources is needed. To address this, we are evolving the DeSiDeRaTa adaptive resource management approach to enable reconfigurable ground and space information systems. The DeSiDeRaTa approach embodies a set of middleware mechanisms for adapting resource allocations, and a framework for reasoning about the real-time performance of distributed application systems. The framework and middleware will be extended to accommodate (1) the dynamic aspects of intra-constellation network topologies, and (2) the complete real-time path from the instrument to the user. We are developing a ground-based testbed that will enable NASA to perform early evaluation of adaptive resource management techniques without the expense of first deploying them in space. The benefits of the proposed effort are numerous, including the ability to use sensors in new ways not anticipated at design time; the production of information technology that ties the sensor web together; the accommodation of greater numbers of missions with fewer resources; and the opportunity to leverage the DeSiDeRaTa project's expertise, infrastructure and models for adaptive resource management for distributed real-time systems.

  14. Vibration Antiresonance Design for a Spacecraft Multifunctional Structure

    Dong-Xu Li

    2017-01-01

    Full Text Available Spacecraft must withstand rigorous mechanical environment experiences such as acceleration, noise, vibration, and shock during the process of launching, satellite-vehicle separation, and so on. In this paper, a new spacecraft multifunctional structure concept designed by us is introduced. The multifunctional structure has the functions of not only load bearing, but also vibration reduction, energy source, thermal control, and so on, and we adopt a series of viscoelastic parts as connections between substructures. Especially in this paper, a vibration antiresonance design method is proposed to realize the vibration reduction. The complex zero-point equations of the vibration system are firstly established, and then the vibration antiresonance design for the system is achieved. For solving the difficulties due to viscoelastic characteristics of the connecting parts, we present the determining formulas to obtain the structural parameters, so that the complex zero-point equations can be satisfied. Numerical simulation and ground experiment demonstrate the correctness and effectiveness of the proposed method. This method can solve the structural vibration control problem under the function constraints of load bearing and energy supplying and will expand the performance of spacecraft functional modules.

  15. Properties of Coronal Shocks at the Origin of SEP events Observed by Only One Single Spacecraft

    Lario, D.; Kwon, R.

    2017-12-01

    The simultaneous observation of solar energetic particle (SEP) events by multiple spacecraft distributed in the interplanetary medium depends not only on the spatial separation among the different spacecraft, but also on the properties of the particle sources and the characteristics of the SEP transport in interplanetary space. Among the SEP events observed by STEREO-A, STEREO-B and/or near-Earth spacecraft during solar cycle 24, we select SEP events observed by a single spacecraft (specifically, the SEP events observed only by near-Earth spacecraft on 2012 April 5, 2011 September 4, and 2013 August 17). We analyze whether the properties of the coronal shock associated with the origin of the events (as seen in extreme-ultraviolet and white-light coronal images) differ from those associated with SEP events observed by two or three spacecraft. For the selected events we find that the associated CMEs are, in general, narrower than those associated with SEP events observed by two or three spacecraft. The confined extension of the parent coronal shock and the absence of magnetic connection between distant spacecraft and the regions of the expanding coronal shock able to efficiently accelerate SEPs seem to be the conditions leading to intense SEP events observed only over narrow regions of interplanetary space by spacecraft magnetically connected to regions close to the parent eruption site. Weak and gradual intensity increases observed in extended regions of space might involve transport processes and/or later connections established with interplanetary shocks. Systematic analyses of a larger number of events are required before drawing firm conclusions.

  16. Directors' report and accounts 1992/1993

    1993-01-01

    This item is the Directors' Report and Accounts for the financial year 1992/1993 for Scottish Hydro-Electric plc, a United Kingdom utility which generates, distributes and sells electricity to its customers in that country. While generation is based in Scotland, the company is seeking to penetrate the energy market in England and Wales, and increase earnings in Scotland through improved performance. Increased customer and shareholder satisfaction is identified as a continuing goal. Turnover, profits and dividends to shareholders have all increased during the year. (UK)

  17. Developing Sustainable Spacecraft Water Management Systems

    Thomas, Evan A.; Klaus, David M.

    2009-01-01

    It is well recognized that water handling systems used in a spacecraft are prone to failure caused by biofouling and mineral scaling, which can clog mechanical systems and degrade the performance of capillary-based technologies. Long duration spaceflight applications, such as extended stays at a Lunar Outpost or during a Mars transit mission, will increasingly benefit from hardware that is generally more robust and operationally sustainable overtime. This paper presents potential design and testing considerations for improving the reliability of water handling technologies for exploration spacecraft. Our application of interest is to devise a spacecraft wastewater management system wherein fouling can be accommodated by design attributes of the management hardware, rather than implementing some means of preventing its occurrence.

  18. Embedded Thermal Control for Spacecraft Subsystems Miniaturization

    Didion, Jeffrey R.

    2014-01-01

    Optimization of spacecraft size, weight and power (SWaP) resources is an explicit technical priority at Goddard Space Flight Center. Embedded Thermal Control Subsystems are a promising technology with many cross cutting NSAA, DoD and commercial applications: 1.) CubeSatSmallSat spacecraft architecture, 2.) high performance computing, 3.) On-board spacecraft electronics, 4.) Power electronics and RF arrays. The Embedded Thermal Control Subsystem technology development efforts focus on component, board and enclosure level devices that will ultimately include intelligent capabilities. The presentation will discuss electric, capillary and hybrid based hardware research and development efforts at Goddard Space Flight Center. The Embedded Thermal Control Subsystem development program consists of interrelated sub-initiatives, e.g., chip component level thermal control devices, self-sensing thermal management, advanced manufactured structures. This presentation includes technical status and progress on each of these investigations. Future sub-initiatives, technical milestones and program goals will be presented.

  19. Low power arcjet system spacecraft impacts

    Pencil, Eric J.; Sarmiento, Charles J.; Lichtin, D. A.; Palchefsky, J. W.; Bogorad, A. L.

    1993-01-01

    Potential plume contamination of spacecraft surfaces was investigated by positioning spacecraft material samples relative to an arcjet thruster. Samples in the simulated solar array region were exposed to the cold gas arcjet plume for 40 hrs to address concerns about contamination by backstreaming diffusion pump oil. Except for one sample, no significant changes were measured in absorptance and emittance within experimental error. Concerns about surface property degradation due to electrostatic discharges led to the investigation of the discharge phenomenon of charged samples during arcjet ignition. Short duration exposure of charged samples demonstrated that potential differences are consistently and completely eliminated within the first second of exposure to a weakly ionized plume. The spark discharge mechanism was not the discharge phenomenon. The results suggest that the arcjet could act as a charge control device on spacecraft.

  20. Relativistic Spacecraft Propelled by Directed Energy

    Kulkarni, Neeraj; Lubin, Philip; Zhang, Qicheng

    2018-04-01

    Achieving relativistic flight to enable extrasolar exploration is one of the dreams of humanity and the long-term goal of our NASA Starlight program. We derive a relativistic solution for the motion of a spacecraft propelled by radiation pressure from a directed energy (DE) system. Depending on the system parameters, low-mass spacecraft can achieve relativistic speeds, thus enabling interstellar exploration. The diffraction of the DE system plays an important role and limits the maximum speed of the spacecraft. We consider “photon recycling” as a possible method to achieving higher speeds. We also discuss recent claims that our previous work on this topic is incorrect and show that these claims arise from an improper treatment of causality.

  1. Numerical Analysis of Magnetic Sail Spacecraft

    Sasaki, Daisuke; Yamakawa, Hiroshi; Usui, Hideyuki; Funaki, Ikkoh; Kojima, Hirotsugu

    2008-01-01

    To capture the kinetic energy of the solar wind by creating a large magnetosphere around the spacecraft, magneto-plasma sail injects a plasma jet into a strong magnetic field produced by an electromagnet onboard the spacecraft. The aim of this paper is to investigate the effect of the IMF (interplanetary magnetic field) on the magnetosphere of magneto-plasma sail. First, using an axi-symmetric two-dimensional MHD code, we numerically confirm the magnetic field inflation, and the formation of a magnetosphere by the interaction between the solar wind and the magnetic field. The expansion of an artificial magnetosphere by the plasma injection is then simulated, and we show that the magnetosphere is formed by the interaction between the solar wind and the magnetic field expanded by the plasma jet from the spacecraft. This simulation indicates the size of the artificial magnetosphere becomes smaller when applying the IMF.

  2. Autonomous Spacecraft Communication Interface for Load Planning

    Dever, Timothy P.; May, Ryan D.; Morris, Paul H.

    2014-01-01

    Ground-based controllers can remain in continuous communication with spacecraft in low Earth orbit (LEO) with near-instantaneous communication speeds. This permits near real-time control of all of the core spacecraft systems by ground personnel. However, as NASA missions move beyond LEO, light-time communication delay issues, such as time lag and low bandwidth, will prohibit this type of operation. As missions become more distant, autonomous control of manned spacecraft will be required. The focus of this paper is the power subsystem. For present missions, controllers on the ground develop a complete schedule of power usage for all spacecraft components. This paper presents work currently underway at NASA to develop an architecture for an autonomous spacecraft, and focuses on the development of communication between the Mission Manager and the Autonomous Power Controller. These two systems must work together in order to plan future load use and respond to unanticipated plan deviations. Using a nominal spacecraft architecture and prototype versions of these two key components, a number of simulations are run under a variety of operational conditions, enabling development of content and format of the messages necessary to achieve the desired goals. The goals include negotiation of a load schedule that meets the global requirements (contained in the Mission Manager) and local power system requirements (contained in the Autonomous Power Controller), and communication of off-plan disturbances that arise while executing a negotiated plan. The message content is developed in two steps: first, a set of rapid-prototyping "paper" simulations are preformed; then the resultant optimized messages are codified for computer communication for use in automated testing.

  3. Statement by IAEA Director General Mohamed ElBaradei

    2008-01-01

    Full text: The IAEA Secretariat was provided with information by the United States on 24 April claiming that the installation destroyed by Israel in Syria last September was a nuclear reactor. According to this information, the reactor was not yet operational and no nuclear material had been introduced into it. The Agency will treat this information with the seriousness it deserves and will investigate the veracity of the information. Syria has an obligation under its Safeguards Agreement with the IAEA to report the planning and construction of any nuclear facility to the Agency. The Director General deplores the fact that this information was not provided to the Agency in a timely manner, in accordance with the Agency's responsibilities under the Nuclear Non-Proliferation Treaty (NPT), to enable it to verify its veracity and establish the facts. Under the NPT, the Agency has a responsibility to verify any proliferation allegations in a non-nuclear weapon State party to the NPT and to report its findings to the IAEA Board of Governors and the Security Council, as required. In light of the above, the Director General views the unilateral use of force by Israel as undermining the due process of verification that is at the heart of the non-proliferation regime. (IAEA)

  4. Operational Philosophy Concerning Manned Spacecraft Cabin Leaks

    DeSimpelaere, Edward

    2011-01-01

    The last thirty years have seen the Space Shuttle as the prime United States spacecraft for manned spaceflight missions. Many lessons have been learned about spacecraft design and operation throughout these years. Over the next few decades, a large increase of manned spaceflight in the commercial sector is expected. This will result in the exposure of commercial crews and passengers to many of the same risks crews of the Space Shuttle have encountered. One of the more dire situations that can be encountered is the loss of pressure in the habitable volume of the spacecraft during on orbit operations. This is referred to as a cabin leak. This paper seeks to establish a general cabin leak response philosophy with the intent of educating future spacecraft designers and operators. After establishing a relative definition for a cabin leak, the paper covers general descriptions of detection equipment, detection methods, and general operational methods for management of a cabin leak. Subsequently, all these items are addressed from the perspective of the Space Shuttle Program, as this will be of the most value to future spacecraft due to similar operating profiles. Emphasis here is placed upon why and how these methods and philosophies have evolved to meet the Space Shuttle s needs. This includes the core ideas of: considerations of maintaining higher cabin pressures vs. lower cabin pressures, the pros and cons of a system designed to feed the leak with gas from pressurized tanks vs. using pressure suits to protect against lower cabin pressures, timeline and consumables constraints, re-entry considerations with leaks of unknown origin, and the impact the International Space Station (ISS) has had to the standard Space Shuttle cabin leak response philosophy. This last item in itself includes: procedural management differences, hardware considerations, additional capabilities due to the presence of the ISS and its resource, and ISS docking/undocking considerations with a

  5. Testing programs for the Multimission Modular Spacecraft

    Greenwell, T. J.

    1978-01-01

    The Multimission Modular Spacecraft (MMS) provides a standard spacecraft bus to a user for a variety of space missions ranging from near-earth to synchronous orbits. The present paper describes the philosophy behind the MMS module test program and discusses the implementation of the test program. It is concluded that the MMS module test program provides an effective and comprehensive customer buy-off at the subsystem contractor's plant, is an optimum approach for checkout of the subsystems prior to use for on-orbit servicing in the Shuttle Cargo Bay, and is a cost-effective technique for environmental testing.

  6. Robust Parametric Control of Spacecraft Rendezvous

    Dake Gu

    2014-01-01

    Full Text Available This paper proposes a method to design the robust parametric control for autonomous rendezvous of spacecrafts with the inertial information with uncertainty. We consider model uncertainty of traditional C-W equation to formulate the dynamic model of the relative motion. Based on eigenstructure assignment and model reference theory, a concise control law for spacecraft rendezvous is proposed which could be fixed through solving an optimization problem. The cost function considers the stabilization of the system and other performances. Simulation results illustrate the robustness and effectiveness of the proposed control.

  7. Spacecraft charging: incoming and outgoing electrons

    Lai, Shu T.

    2013-04-22

    This paper presents an overview of the roles played by incoming and outgoing electrons in spacecraft surface and stresses the importance of surface conditions for spacecraft charging. The balance between the incoming electron current from the ambient plasma and the outgoing currents of secondary electrons, backscattered electrons, and photoelectrons from the surfaces determines the surface potential. Since surface conditions significantly affect the outgoing currents, the critical temperature and the surface potential are also significantly affected. As a corollary, high level differential charging of adjacent surfaces with very different surface conditions is a space hazard.

  8. Event-triggered attitude control of spacecraft

    Wu, Baolin; Shen, Qiang; Cao, Xibin

    2018-02-01

    The problem of spacecraft attitude stabilization control system with limited communication and external disturbances is investigated based on an event-triggered control scheme. In the proposed scheme, information of attitude and control torque only need to be transmitted at some discrete triggered times when a defined measurement error exceeds a state-dependent threshold. The proposed control scheme not only guarantees that spacecraft attitude control errors converge toward a small invariant set containing the origin, but also ensures that there is no accumulation of triggering instants. The performance of the proposed control scheme is demonstrated through numerical simulation.

  9. The spacecraft encounters of Comet Halley

    Asoka Mendis, D.; Tsurutani, Bruce T.

    1986-01-01

    The characteristics of the Comet Halley spacecraft 'fleet' (VEGA 1 and VEGA 2, Giotto, Suisei, and Sakigake) are presented. The major aims of these missions were (1) to discover and characterize the nucleus, (2) to characterize the atmosphere and ionosphere, (3) to characterize the dust, and (4) to characterize the nature of the large-scale comet-solar wind interaction. While the VEGA and Giotto missions were designed to study all four areas, Suisei addressed the second and fourth. Sakigake was designed to study the solar wind conditions upstream of the comet. It is noted that NASA's Deep Space Network played an important role in spacecraft tracking.

  10. Probabilistic Risk Assessment for Decision Making During Spacecraft Operations

    Meshkat, Leila

    2009-01-01

    , provide insight into the effect of various faults or failures on the risk and failure drivers of the system and the likelihood of possible end case scenarios, thereby facilitating the decision making process during operations. This paper describes the process of adjusting PRA models based on observed spacecraft data, on one hand, and utilizing the models for insight into the future system behavior on the other hand. While PRA models are typically used as a decision aid during the design phase of a space mission, we advocate adjusting them based on the observed behavior of the spacecraft and utilizing them for decision support during the operations phase.

  11. Flight Plasma Diagnostics for High-Power, Solar-Electric Deep-Space Spacecraft

    Johnson, Lee; De Soria-Santacruz Pich, Maria; Conroy, David; Lobbia, Robert; Huang, Wensheng; Choi, Maria; Sekerak, Michael J.

    2018-01-01

    NASA's Asteroid Redirect Robotic Mission (ARRM) project plans included a set of plasma and space environment instruments, the Plasma Diagnostic Package (PDP), to fulfill ARRM requirements for technology extensibility to future missions. The PDP objectives were divided into the classes of 1) Plasma thruster dynamics, 2) Solar array-specific environmental effects, 3) Plasma environmental spacecraft effects, and 4) Energetic particle spacecraft environment. A reference design approach and interface requirements for ARRM's PDP was generated by the PDP team at JPL and GRC. The reference design consisted of redundant single-string avionics located on the ARRM spacecraft bus as well as solar array, driving and processing signals from multiple copies of several types of plasma, effects, and environments sensors distributed over the spacecraft and array. The reference design sensor types were derived in part from sensors previously developed for USAF Research Laboratory (AFRL) plasma effects campaigns such as those aboard TacSat-2 in 2007 and AEHF-2 in 2012.

  12. A new director for Arts@CERN

    CERN Bulletin

    2015-01-01

    On 2 March 2015, Mónica Bello will take the reins of the Arts@CERN programme. A few days before taking over the new job, the curator and art critic talked to the CERN Bulletin about her interest in arts and science, her motivations for the job, and her plans for the future of the programme.   Mónica Bello. “The exciting nature of CERN almost demands an artistic programme like Arts@CERN,” says Mónica, former artistic director of VIDA (one of the most important competitions in digital and new media arts worldwide), who has recently been appointed as the new director of the Arts@CERN programme. “The programme is unique as it provides the artist not only with resources, but also with interesting scientific topics and a natural way for the artists to become involved. Thanks to this programme, artists can come to CERN, bring their individuality, and really benefit from the sharing experience with scientists.” Mónica,...

  13. An interview with the Director-General

    James Gillies

    2012-01-01

    At its March meeting, the Council took the step of extending Rolf Heuer’s mandate until the end of 2015. What can we expect from the extra two years?   Extensions to Director-General’s mandates are few and far between, with the last being for Herwig Schopper, who served an eight-year term in the 1980s. For Rolf Heuer, the proposal was raised by the Belgian delegation, so we asked delegate Walter Van Doninck why the Council felt that circumstances warranted an extension now. “We felt that the LHC's first long shutdown needed management continuity, given the important nature of the work to be carried out,” he explained. “That’s why we proposed extending the mandate of the current Director-General.” James Gillies spoke to Professor Heuer to find out what he plans to achieve with the extra time. James Gillies: First of all, how do you feel about your time in office so far? Rolf Heuer: I feel I’m about midwa...

  14. Spacecraft Architecture and environmental pshychology

    Ören, Ayşe

    2016-07-01

    As we embark on a journey for new homes in the new worlds to lay solid foundations, we should consider not only the survival of frontiers but also well-being of those to live in zero gravity. As a versatile science, architecture encompasses abstract human needs as well. On our new different direction in the course of the Homo sapiens evolution, we can do this with designs addressing both our needs and senses. Well-being of humans can be achieved by creating environments supporting the cognitive and social stages in the evolution process. Space stations are going through their own evolution process. Any step taken can serve as a reference for further attempts. When studying the history of architecture, window designing is discussed in a later phase, which is the case for building a spaceship as well. We lean on the places we live both physically and metaphorically. The feeling of belonging is essential here, entailing trans-humanism, which is significant since the environment therein is like a dress comfortable enough to fit in, meeting needs without any burden. Utilizing the advent of technology, we can create moods and atmospheres to regulate night and day cycles, thus we can turn claustrophobic places into cozy or dream-like places. Senses provoke a psychological sensation going beyond cultural codes as they are rooted within consciousness, which allows designers to create a mood within a space that tells a story and evokes an emotional impact. Color, amount of light, sound and odor are not superficial. As much as intangible, they are real and powerful tools with a physical presence. Tapping into induction, we can solve a whole system based on a part thereof. Therefore, fractal designs may not yield good results unless used correctly in terms of design although they are functional, which makes geometric arrangement critical.

  15. Spacecraft Architecture and well being

    Ören, Ayşe

    2016-07-01

    As we embark on a journey for new homes in the new worlds to lay solid foundations, we should consider not only the survival of frontiers but also well-being of those to live in zero gravity. As a versatile science, architecture encompasses abstract human needs as well. On our new different direction in the course of the Homo sapiens evolution, we can do this with designs addressing both our needs and senses. Well-being of humans can be achieved by creating environments supporting the cognitive and social stages in the evolution process. Space stations are going through their own evolution process. Any step taken can serve as a reference for further attempts. When studying the history of architecture, window designing is discussed in a later phase, which is the case for building a spaceship as well. We lean on the places we live both physically and metaphorically. The feeling of belonging is essential here, entailing trans-humanism, which is significant since the environment therein is like a dress comfortable enough to fit in, meeting needs without any burden. Utilizing the advent of technology, we can create moods and atmospheres to regulate night and day cycles, thus we can turn claustrophobic places into cozy or dream-like places. Senses provoke a psychological sensation going beyond cultural codes as they are rooted within consciousness, which allows designers to create a mood within a space that tells a story and evokes an emotional impact. Color, amount of light, sound and odor are not superficial. As much as intangible, they are real and powerful tools with a physical presence. Tapping into induction, we can solve a whole system based on a part thereof. Therefore, fractal designs may not yield good results unless used correctly in terms of design although they are functional, which makes geometric arrangement critical.

  16. Software for Engineering Simulations of a Spacecraft

    Shireman, Kirk; McSwain, Gene; McCormick, Bernell; Fardelos, Panayiotis

    2005-01-01

    Spacecraft Engineering Simulation II (SES II) is a C-language computer program for simulating diverse aspects of operation of a spacecraft characterized by either three or six degrees of freedom. A functional model in SES can include a trajectory flight plan; a submodel of a flight computer running navigational and flight-control software; and submodels of the environment, the dynamics of the spacecraft, and sensor inputs and outputs. SES II features a modular, object-oriented programming style. SES II supports event-based simulations, which, in turn, create an easily adaptable simulation environment in which many different types of trajectories can be simulated by use of the same software. The simulation output consists largely of flight data. SES II can be used to perform optimization and Monte Carlo dispersion simulations. It can also be used to perform simulations for multiple spacecraft. In addition to its generic simulation capabilities, SES offers special capabilities for space-shuttle simulations: for this purpose, it incorporates submodels of the space-shuttle dynamics and a C-language version of the guidance, navigation, and control components of the space-shuttle flight software.

  17. How Spacecraft Fly Spaceflight Without Formulae

    Swinerd, Graham

    2009-01-01

    About half a century ago a small satellite, Sputnik 1, was launched. The satellite did very little other than to transmit a radio signal to announce its presence in orbit. However, this humble beginning heralded the dawn of the Space Age. Today literally thousands of robotic spacecraft have been launched, many of which have flown to far-flung regions of the Solar System carrying with them the human spirit of scientific discovery and exploration. Numerous other satellites have been launched in orbit around the Earth providing services that support our technological society on the ground. How Spacecraft Fly: Spaceflight Without Formulae by Graham Swinerd focuses on how these spacecraft work. The book opens with a historical perspective of how we have come to understand our Solar System and the Universe. It then progresses through orbital flight, rocket science, the hostile environment within which spacecraft operate, and how they are designed. The concluding chapters give a glimpse of what the 21st century may ...

  18. Microgravity Flammability Experiments for Spacecraft Fire Safety

    Legros, Guillaume; Minster, Olivier; Tóth, Balazs

    2012-01-01

    As fire behaviour in manned spacecraft still remains poorly understood, an international topical team has been created to design a validation experiment that has an unprecedented large scale for a microgravity flammability experiment. While the validation experiment is being designed for a re-sup...

  19. Spacecraft 3D Augmented Reality Mobile App

    Hussey, Kevin J.; Doronila, Paul R.; Kumanchik, Brian E.; Chan, Evan G.; Ellison, Douglas J.; Boeck, Andrea; Moore, Justin M.

    2013-01-01

    The Spacecraft 3D application allows users to learn about and interact with iconic NASA missions in a new and immersive way using common mobile devices. Using Augmented Reality (AR) techniques to project 3D renditions of the mission spacecraft into real-world surroundings, users can interact with and learn about Curiosity, GRAIL, Cassini, and Voyager. Additional updates on future missions, animations, and information will be ongoing. Using a printed AR Target and camera on a mobile device, users can get up close with these robotic explorers, see how some move, and learn about these engineering feats, which are used to expand knowledge and understanding about space. The software receives input from the mobile device's camera to recognize the presence of an AR marker in the camera's field of view. It then displays a 3D rendition of the selected spacecraft in the user's physical surroundings, on the mobile device's screen, while it tracks the device's movement in relation to the physical position of the spacecraft's 3D image on the AR marker.

  20. Special Semaphore Scheme for UHF Spacecraft Communications

    Butman, Stanley; Satorius, Edgar; Ilott, Peter

    2006-01-01

    A semaphore scheme has been devised to satisfy a requirement to enable ultrahigh- frequency (UHF) radio communication between a spacecraft descending from orbit to a landing on Mars and a spacecraft, in orbit about Mars, that relays communications between Earth and the lander spacecraft. There are also two subsidiary requirements: (1) to use UHF transceivers, built and qualified for operation aboard the spacecraft that operate with residual-carrier binary phase-shift-keying (BPSK) modulation at a selectable data rate of 8, 32, 128, or 256 kb/s; and (2) to enable low-rate signaling even when received signals become so weak as to prevent communication at the minimum BPSK rate of 8 kHz. The scheme involves exploitation of Manchester encoding, which is used in conjunction with residual-carrier modulation to aid the carrier-tracking loop. By choosing various sequences of 1s, 0s, or 1s alternating with 0s to be fed to the residual-carrier modulator, one would cause the modulator to generate sidebands at a fundamental frequency of 4 or 8 kHz and harmonics thereof. These sidebands would constitute the desired semaphores. In reception, the semaphores would be detected by a software demodulator.

  1. Accelerated life testing of spacecraft subsystems

    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.

  2. Rotational Motion Control of a Spacecraft

    Wisniewski, Rafal; Kulczycki, P.

    2001-01-01

    The paper adopts the energy shaping method to control of rotational motion. A global representation of the rigid body motion is given in the canonical form by a quaternion and its conjugate momenta. A general method for motion control on a cotangent bundle to the 3-sphere is suggested. The design...... algorithm is validated for three-axis spacecraft attitude control...

  3. Rotational motion control of a spacecraft

    Wisniewski, Rafal; Kulczycki, P.

    2003-01-01

    The paper adopts the energy shaping method to control of rotational motion. A global representation of the rigid body motion is given in the canonical form by a quaternion and its conjugate momenta. A general method for motion control on a cotangent bundle to the 3-sphere is suggested. The design...... algorithm is validated for three-axis spacecraft attitude control. Udgivelsesdato: APR...

  4. Small Spacecraft Technology Initiative Education Program

    1995-01-01

    A NASA engineer with the Commercial Remote Sensing Program (CRSP) at Stennis Space Center works with students from W.P. Daniels High School in New Albany, Miss., through NASA's Small Spacecraft Technology Initiative Program. CRSP is teaching students to use remote sensing to locate a potential site for a water reservoir to offset a predicted water shortage in the community's future.

  5. Spacecraft Attitude Control in Hamiltonian Framework

    Wisniewski, Rafal

    2000-01-01

    The objective of this paper is to give a design scheme for attitude control algorithms of a generic spacecraft. Along with the system model formulated in the Hamilton's canonical form the algorithm uses information about a required potential energy and a dissipative term. The control action...

  6. A Comprehensive Characterization of Microorganisms and Allergens in Spacecraft Environment

    Castro, V.A.; Ott, C.M.; Garcia, V.M.; John, J.; Buttner, M.P.; Cruz, P.; Pierson, D.L.

    2009-01-01

    The determination of risk from infectious disease during long-duration missions is composed of several factors including the concentration and the characteristics of the infectious agent. Thus, a thorough knowledge of the microorganisms aboard spacecraft is essential in mitigating infectious disease risk to the crew. While stringent steps are taken to minimize the transfer of potential pathogens to spacecraft, several medically significant organisms have been isolated from both the Mir and International Space Station (ISS). Historically, the method for isolation and identification of microorganisms from spacecraft environmental samples depended upon their growth on culture media. Unfortunately, only a fraction of the organisms may grow on a culture medium, potentially omitting those microorganisms whose nutritional and physical requirements for growth are not met. Thus, several pathogens may not have been detected, such as Legionella pneumophila, the etiological agent of Legionnaire s disease. We hypothesize that environmental analysis using non-culture-based technologies will reveal microorganisms, allergens, and microbial toxins not previously reported in spacecraft, allowing for a more complete health assessment. The development of techniques for this flight experiment, operationally named SWAB, has already provided advances in NASA laboratory processes and beneficial information toward human health risk assessment. The translation of 16S ribosomal DNA sequencing for the identification of bacteria from the SWAB experiment to nominal operations has increased bacterial speciation of environmental isolates from previous flights three fold compared to previous conventional methodology. The incorporation of molecular-based DNA fingerprinting using repetitive sequence-based polymerase chain reaction (rep-PCR) into the capabilities of the laboratory has provided a methodology to track microorganisms between crewmembers and their environment. Both 16S ribosomal DNA

  7. Characterization of spacecraft humidity condensate

    Muckle, Susan; Schultz, John R.; Sauer, Richard L.

    1994-01-01

    When construction of Space Station Freedom reaches the Permanent Manned Capability (PMC) stage, the Water Recovery and Management Subsystem will be fully operational such that (distilled) urine, spent hygiene water, and humidity condensate will be reclaimed to provide water of potable quality. The reclamation technologies currently baselined to process these waste waters include adsorption, ion exchange, catalytic oxidation, and disinfection. To ensure that the baseline technologies will be able to effectively remove those compounds presenting a health risk to the crew, the National Research Council has recommended that additional information be gathered on specific contaminants in waste waters representative of those to be encountered on the Space Station. With the application of new analytical methods and the analysis of waste water samples more representative of the Space Station environment, advances in the identification of the specific contaminants continue to be made. Efforts by the Water and Food Analytical Laboratory at JSC were successful in enlarging the database of contaminants in humidity condensate. These efforts have not only included the chemical characterization of condensate generated during ground-based studies, but most significantly the characterization of cabin and Spacelab condensate generated during Shuttle missions. The analytical results presented in this paper will be used to show how the composition of condensate varies amongst enclosed environments and thus the importance of collecting condensate from an environment close to that of the proposed Space Station. Although advances were made in the characterization of space condensate, complete characterization, particularly of the organics, requires further development of analytical methods.

  8. Navigating the MESSENGER Spacecraft through End of Mission

    Bryan, C. G.; Williams, B. G.; Williams, K. E.; Taylor, A. H.; Carranza, E.; Page, B. R.; Stanbridge, D. R.; Mazarico, E.; Neumann, G. A.; O'Shaughnessy, D. J.; McAdams, J. V.; Calloway, A. B.

    2015-12-01

    The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft orbited the planet Mercury from March 2011 until the end of April 2015, when it impacted the planetary surface after propellant reserves used to maintain the orbit were depleted. This highly successful mission was led by the principal investigator, Sean C. Solomon, of Columbia University. The Johns Hopkins University Applied Physics Laboratory (JHU/APL) designed and assembled the spacecraft and served as the home for spacecraft operations. Spacecraft navigation for the entirety of the mission was provided by the Space Navigation and Flight Dynamics Practice (SNAFD) of KinetX Aerospace. Orbit determination (OD) solutions were generated through processing of radiometric tracking data provided by NASA's Deep Space Network (DSN) using the MIRAGE suite of orbital analysis tools. The MESSENGER orbit was highly eccentric, with periapsis at a high northern latitude and periapsis altitude in the range 200-500 km for most of the orbital mission phase. In a low-altitude "hover campaign" during the final two months of the mission, periapsis altitudes were maintained within a narrow range between about 35 km and 5 km. Navigating a spacecraft so near a planetary surface presented special challenges. Tasks required to meet those challenges included the modeling and estimation of Mercury's gravity field and of solar and planetary radiation pressure, and the design of frequent orbit-correction maneuvers. Superior solar conjunction also presented observational modeling issues. One key to the overall success of the low-altitude hover campaign was a strategy to utilize data from an onboard laser altimeter as a cross-check on the navigation team's reconstructed and predicted estimates of periapsis altitude. Data obtained from the Mercury Laser Altimeter (MLA) on a daily basis provided near-real-time feedback that proved invaluable in evaluating alternative orbit estimation strategies, and

  9. 4th July 2011 - Russian Deputy Director-General Director of Directorate for Scientific and Technical Complex ROSATOM V. Pershukov in the ATLAS underground experimental area with Adviser T. Kurtyka, ATLAS Technical Coordinator M. Nessi and ATLAS Russian users.

    Maximilien Brice

    2011-01-01

    4th July 2011 - Russian Deputy Director-General Director of Directorate for Scientific and Technical Complex ROSATOM V. Pershukov in the ATLAS underground experimental area with Adviser T. Kurtyka, ATLAS Technical Coordinator M. Nessi and ATLAS Russian users.

  10. Automated Spacecraft Conjunction Assessment at Mars and the Moon

    Berry, David; Guinn, Joseph; Tarzi, Zahi; Demcak, Stuart

    2012-01-01

    Conjunction assessment and collision avoidance are areas of current high interest in space operations. Most current conjunction assessment activity focuses on the Earth orbital environment. Several of the world's space agencies have satellites in orbit at Mars and the Moon, and avoiding collisions there is important too. Smaller number of assets than Earth, and smaller number of organizations involved, but consequences similar to Earth scenarios.This presentation will examine conjunction assessment processes implemented at JPL for spacecraft in orbit at Mars and the Moon.

  11. On the spacecraft attitude stabilization in the orbital frame

    Antipov Kirill A.

    2012-01-01

    Full Text Available The paper deals with spacecraft in the circular near-Earth orbit. The spacecraft interacts with geomagnetic field by the moments of Lorentz and magnetic forces. The octupole approximation of the Earth’s magnetic field is accepted. The spacecraft electromagnetic parameters, namely the electrostatic charge moment of the first order and the eigen magnetic moment are the controlled quasiperiodic functions. The control algorithms for the spacecraft electromagnetic parameters, which allows to stabilize the spacecraft attitude position in the orbital frame are obtained. The stability of the spacecraft stabilized orientation is proved both analytically and by PC computations.

  12. Spacecraft Internal Acoustic Environment Modeling

    Chu, Shao-Sheng R.; Allen Christopher S.

    2010-01-01

    Acoustic modeling can be used to identify key noise sources, determine/analyze sub-allocated requirements, keep track of the accumulation of minor noise sources, and to predict vehicle noise levels at various stages in vehicle development, first with estimates of noise sources, later with experimental data. This paper describes the implementation of acoustic modeling for design purposes by incrementally increasing model fidelity and validating the accuracy of the model while predicting the noise of sources under various conditions. During FY 07, a simple-geometry Statistical Energy Analysis (SEA) model was developed and validated using a physical mockup and acoustic measurements. A process for modeling the effects of absorptive wall treatments and the resulting reverberation environment were developed. During FY 08, a model with more complex and representative geometry of the Orion Crew Module (CM) interior was built, and noise predictions based on input noise sources were made. A corresponding physical mockup was also built. Measurements were made inside this mockup, and comparisons were made with the model and showed excellent agreement. During FY 09, the fidelity of the mockup and corresponding model were increased incrementally by including a simple ventilation system. The airborne noise contribution of the fans was measured using a sound intensity technique, since the sound power levels were not known beforehand. This is opposed to earlier studies where Reference Sound Sources (RSS) with known sound power level were used. Comparisons of the modeling result with the measurements in the mockup showed excellent results. During FY 10, the fidelity of the mockup and the model were further increased by including an ECLSS (Environmental Control and Life Support System) wall, associated closeout panels, and the gap between ECLSS wall and mockup wall. The effect of sealing the gap and adding sound absorptive treatment to ECLSS wall were also modeled and validated.

  13. SMART-1: the first spacecraft of the future

    2003-09-01

    gather high-value scientific and technological data. Another innovation lies in the industrial policy applied to this mission. SMART-1 is a good example of an ESA mission in which a comparatively small company such as the Swedish Space Corporation (SSC) has been selected as prime contractor. “The experience of SSC in highly successful projects at national level was a key factor in the decision, as was ESA's goal of fostering a balanced industrial landscape in Europe,” says Niels Jensen of ESA’s Directorate of Industrial Matters and Technology Programmes. The magic of ion engines Solar-electric propulsion, one of the main technologies to be tested by SMART-1, is a new technique that uses 'ion engines'. These work by expelling a continuous beam of charged particles --ions-- at the back of the engine, which produces a thrust in the opposite direction and therefore pushes the spacecraft forward. The energy to feed the engine comes from the solar panels, hence the name 'solar-electric propulsion'. Engineers have been working on ion engines for decades, but only recently have obstacles such as the lack of power availability from a spacecraft’s solar panels been overcome. Recent missions have been using ion thrusters mainly for attitude control and orbit station keeping. In the recent case of ESA’s telecommunication satellite Artemis, the onboard availability of ion thrusters was actually what allowed the mission to be rescued. Having been left by the launcher on an unplanned orbit, Artemis was slowly - but safely - brought up to its final working orbit by the power of its ion engines, initially designed for orbit maintenance only. Starting with SMART-1, the first European spacecraft to use an ion engine as its main propulsion system, the amazing advantages of this method can now be fully exploited. Ion engines are very efficient: they deliver about ten times as much impulse per kilogram of propellant used. This gives a substantial reduction in the mass of the fuel

  14. 2015 Science Mission Directorate Technology Highlights

    Seablom, Michael S.

    2016-01-01

    The role of the Science Mission Directorate (SMD) is to enable NASA to achieve its science goals in the context of the Nation's science agenda. SMD's strategic decisions regarding future missions and scientific pursuits are guided by Agency goals, input from the science community including the recommendations set forth in the National Research Council (NRC) decadal surveys and a commitment to preserve a balanced program across the major science disciplines. Toward this end, each of the four SMD science divisions -- Heliophysics, Earth Science, Planetary Science, and Astrophysics -- develops fundamental science questions upon which to base future research and mission programs. Often the breakthrough science required to answer these questions requires significant technological innovation, e.g., instruments or platforms with capabilities beyond the current state of the art. SMD's targeted technology investments fill technology gaps, enabling NASA to build the challenging and complex missions that accomplish groundbreaking science.

  15. Nanotechnology Concepts at MSFC: Engineering Directorate

    Bhat, Biliyar; Kaul, Raj; Shah, Sandeep; Smithers, Gweneth; Watson, Michael D.

    2000-01-01

    Nanotechnology is the art and science of building materials and devices at the ultimate level of finesse: atom by atom. Our nation's space program has needs for miniaturization of components, minimization of weight and maximization of performance, and nanotechnology will help us get there. MSFC - Engineering Directorate (ED) is committed to developing nanotechnology that will enable MSFC missions in space transportation, space science and space optics manufacturing. MSFC-ED has a dedicated group of technologists who are currently developing high pay-off nanotechnology concepts. This poster presentation will outline some of the concepts being developed at this time including, nanophase structural materials, carbon nanotube reinforced metal and polymer matrix composites, nanotube temperature sensors and aerogels. The poster will outline these concepts and discuss associated technical challenges in turning these concepts into real components and systems.

  16. Surviving the First Three Months as a Community College Library Director

    Kelly, Robert E., IV

    2003-01-01

    The experiences of a first-time community college library director during the initial three months on the job are detailed. The process of automation software migration is used as a vehicle for demonstrating activities performed to improve knowledge. Marketing, customer service, and identification of core library supporters are addressed. Concern…

  17. Institutional Planning: What Role for Directors of Student Admissions and Financial Aid?

    Haines, John R.

    1976-01-01

    According to the director of Higher Education Management Services for the New York State Education Department, the offices of admissions and student financial aid have long been excluded from the institutional planning process. In an era of projected enrollment declines and increased competition, these offices need to assume a critical new role.…

  18. The director task: A test of Theory-of-Mind use or selective attention?

    Rubio-Fernández, Paula

    2017-08-01

    Over two decades, the director task has increasingly been employed as a test of the use of Theory of Mind in communication, first in psycholinguistics and more recently in social cognition research. A new version of this task was designed to test two independent hypotheses. First, optimal performance in the director task, as established by the standard metrics of interference, is possible by using selective attention alone, and not necessarily Theory of Mind. Second, pragmatic measures of Theory-of-Mind use can reveal that people actively represent the director's mental states, contrary to recent claims that they only use domain-general cognitive processes to perform this task. The results of this study support both hypotheses and provide a new interactive paradigm to reliably test Theory-of-Mind use in referential communication.

  19. 23rd October 2010 - UNESCO Director-General I. Bokova signing the Guest Book with CERN Director for Research and Scientific Computing S. Bertolucci and CERN Director-General R. Heuer.

    Maximilien Brice

    2010-01-01

    CERN-HI-1010244 37: in the SM18 hall: Ms Jasmina Sopova, Communication Officer J. Sopova; Director, Division of Basic & Engineering Sciences M. Nalecz, Assistant Director-General for the Natural Sciences G. Kalonji; Former CERN Director-General H. Schopper, CERN Head of Education R. Landua; UNESCO Director-General I. Bokova; CERN Adviser M. Bona; CERN Director for Research and Scientific Computing S. Bertolucci and UNESCO Office in Geneva Director Luis M. Tiburcio.

  20. INTERFIRM COOPERATION AND INFORMATION SHARING THROUGH INTERLOCKING DIRECTORATES

    Mohammed Belal UDDIN

    2012-01-01

    Full Text Available When firms engage in cooperative efforts, interfirm relations get particular interest to be studied. A direct interlock occurs when an executive or director of one firm sits on the board of another firm, and an indirect interlock occurs when two firms have directors or executives who sit on the board of a third firm. The three commonly used theoretical models such as social network theory, learning theory, and theory of strategic choice are more relevant for the formation and management of interlocking directorates. Uncertainty, resource scarcity, mutual trust, dependency, etc. influence the formation of interlocking directorates. Consequently, interlocking directorates allow sharing of information and overall cooperation between partners through learning, collaboration, networking, and effective relationship, etc. Proper management of interlocking directorates requires communication and collaboration among partners that enhance exchange of knowledge and cooperation.

  1. Misleading outside directors in public companies – The Israeli case

    David A. Frenkel

    2006-01-01

    Full Text Available The external directors, who serve by law on the board of directors, are responsible for ensuring that, in addition to protecting the interests of stakeholders, the company will take the public interest into consideration. In this research we critically assess this system of corporate governance, and examine whether the external directors can actually succeed in looking out for the public’s interest. The research is based on in-depth interviews with external directors of leading public companies in Israel, representing different sectors. The issue at stake is both conceptual and practical: Conceptually there is an issue of how the notion of "the public interest" is understood and whether the legal construct of "outside directors" is capable of manifesting the public interest. Practically the issue at stake has to do with organisational sociology and how the relations within the Board are set and who are the outside directors.

  2. Application of Space Environmental Observations to Spacecraft Pre-Launch Engineering and Spacecraft Operations

    Barth, Janet L.; Xapsos, Michael

    2008-01-01

    This presentation focuses on the effects of the space environment on spacecraft systems and applying this knowledge to spacecraft pre-launch engineering and operations. Particle radiation, neutral gas particles, ultraviolet and x-rays, as well as micrometeoroids and orbital debris in the space environment have various effects on spacecraft systems, including degradation of microelectronic and optical components, physical damage, orbital decay, biasing of instrument readings, and system shutdowns. Space climate and weather must be considered during the mission life cycle (mission concept, mission planning, systems design, and launch and operations) to minimize and manage risk to both the spacecraft and its systems. A space environment model for use in the mission life cycle is presented.

  3. The Effects of Leader-Member Exchanges on the Relationships Between Extension Agents and County Extension Directors in Florida

    Matt Benge

    2017-03-01

    Full Text Available The relationship between a supervisor and employee has a direct effect on the employee’s job satisfaction, work productivity, and efficiency. Understanding the interactions between Extension agents and County Extension Directors is critical to maintaining positive relationships and providing adequate support to Extension supervisors through professional development and training opportunities. This article examined the dyadic relationships between Extension agents and County Extension Directors in Florida. The majority of Florida Extension agents have high-quality relationship with their County Extension Directors. In addition, over half of relationships of five years or less are in the partner phase, suggesting new employees of the Florida Cooperative Extension Service progress through the leadership making process in a relatively short amount of time. UF/IFAS Extension Administration should provide increased leadership training for County Extension Directors to ensure all dyads progress through the leadership-making process to the partner phase, such as relationship building, and management and supervisory training.

  4. SHARP: A multi-mission artificial intelligence system for spacecraft telemetry monitoring and diagnosis

    Lawson, Denise L.; James, Mark L.

    1989-01-01

    The Spacecraft Health Automated Reasoning Prototype (SHARP) is a system designed to demonstrate automated health and status analysis for multi-mission spacecraft and ground data systems operations. Telecommunications link analysis of the Voyager 2 spacecraft is the initial focus for the SHARP system demonstration which will occur during Voyager's encounter with the planet Neptune in August, 1989, in parallel with real time Voyager operations. The SHARP system combines conventional computer science methodologies with artificial intelligence techniques to produce an effective method for detecting and analyzing potential spacecraft and ground systems problems. The system performs real time analysis of spacecraft and other related telemetry, and is also capable of examining data in historical context. A brief introduction is given to the spacecraft and ground systems monitoring process at the Jet Propulsion Laboratory. The current method of operation for monitoring the Voyager Telecommunications subsystem is described, and the difficulties associated with the existing technology are highlighted. The approach taken in the SHARP system to overcome the current limitations is also described, as well as both the conventional and artificial intelligence solutions developed in SHARP.

  5. SHARP: A multi-mission AI system for spacecraft telemetry monitoring and diagnosis

    Lawson, Denise L.; James, Mark L.

    1989-01-01

    The Spacecraft Health Automated Reasoning Prototype (SHARP) is a system designed to demonstrate automated health and status analysis for multi-mission spacecraft and ground data systems operations. Telecommunications link analysis of the Voyager II spacecraft is the initial focus for the SHARP system demonstration which will occur during Voyager's encounter with the planet Neptune in August, 1989, in parallel with real-time Voyager operations. The SHARP system combines conventional computer science methodologies with artificial intelligence techniques to produce an effective method for detecting and analyzing potential spacecraft and ground systems problems. The system performs real-time analysis of spacecraft and other related telemetry, and is also capable of examining data in historical context. A brief introduction is given to the spacecraft and ground systems monitoring process at the Jet Propulsion Laboratory. The current method of operation for monitoring the Voyager Telecommunications subsystem is described, and the difficulties associated with the existing technology are highlighted. The approach taken in the SHARP system to overcome the current limitations is also described, as well as both the conventional and artificial intelligence solutions developed in SHARP.

  6. Multi-Spacecraft Study of Kinetic scale Turbulence Using MMS Observations in the Solar Wind

    Chasapis, A.; Matthaeus, W. H.; Parashar, T.; Fuselier, S. A.; Maruca, B.; Burch, J.; Moore, T. E.; Phan, T.; Pollock, C. J.; Gershman, D. J.; Torbert, R. B.; Russell, C. T.; Strangeway, R. J.

    2017-12-01

    We present a study investigating kinetic scale turbulence in the solar wind. Most previous studies relied on single spacecraft measurements, employing the Taylor hypothesis in order to probe different scales. The small separation of MMS spacecraft, well below the ion inertial scale, allow us for the first time to directly probe turbulent fluctuations at the kinetic range. Using multi-spacecraft measurements, we are able to measure the spatial characteristics of turbulent fluctuations and compare with the traditional Taylor-based single spacecraft approach. Meanwhile, combining observations from Cluster and MMS data we were able to cover a wide range of scales from the inertial range where the turbulent cascade takes place, down to the kinetic range where the energy is eventually dissipated. These observations present an important step in understanding the nature of solar wind turbulence and the processes through which turbulent energy is dissipated into particle heating and acceleration. We compute statistical quantities such as the second order structure function and the scale-dependent kurtosis, along with their dependence on the parameters such as the mean magnetic field direction. Overall, we observe an overall agreement between the single spacecraft and the multi-spacecraft approach. However, a small but significant deviation is observed at the smaller scales near the electron inertial scale. The high values of the scale dependent kurtosis at very small scales, observed via two-point measurements, open up a compelling avenue of investigation for theory and numerical modelling.

  7. Council appoints CERN’s next Director General

    Maximilien Brice

    2007-01-01

    On 14 December 2007, CERN Council appointed Professor Rolf-Dieter Heuer to succeed Dr Robert Aymar as CERN Director General. Professor Heuer will serve a five-year term, taking office on 1 January 2009. From Left to right: Dr Robert Aymar, current CERN Director General, Professor Torsten Åkesson, President of CERN Council, and Professor Rolf-Dieter Heuer, CERN's next Director General.

  8. Female Institutional Directors on Boards and Firm Value

    Pucheta Martínez, María Consuelo; Bel Oms, Inmaculada; Olcina Sempere, Gustau

    2016-01-01

    The aim of this research is to examine what impact female institutional directors on boards have on corporate performance. Previous research shows that institutional female directors cannot be considered as a homogeneous group since they represent investors who may or may not maintain business relations with the companies on whose corporate boards they sit. Thus, it is not only the effect of female institutional directors as a whole on firm value that has been analysed, but also the impact of...

  9. Management and Use of Director, Operational Test and Evaluation Funds

    2000-01-01

    .... The reorganization disestablished the functions of the Director, Test, Systems Engineering, and Evaluation, within the Office of Under Secretary of Defense for Acquisition, Technology, and Logistics...

  10. 12 CFR 905.10 - Board of Directors.

    2010-01-01

    ... the five directors may belong to the same political party. (2) Responsibilities. The Board of..., functioning and organization of the Finance Board; (iii) Ensuring effective coordination and communication...

  11. Navigation Operations with Prototype Components of an Automated Real-Time Spacecraft Navigation System

    Cangahuala, L.; Drain, T. R.

    1999-01-01

    At present, ground navigation support for interplanetary spacecraft requires human intervention for data pre-processing, filtering, and post-processing activities; these actions must be repeated each time a new batch of data is collected by the ground data system.

  12. Assessment of Spacecraft Operational Status Using Electro-Optical Predictive Techniques

    2010-09-01

    panel appendages, may require enhanced preflight characterization processes to support monitoring by passive, remote, nonimaging optical sensors...observing and characterizing key spacecraft features. The simulation results are based on electro-optical signatures apparent to nonimaging sensors, along...and communication equipment, may require enhanced preflight characterization processes to support monitoring by passive, remote, nonimaging optical

  13. DOD Recovery personnel and NASA technicians inspect Friendship 7 spacecraft

    1964-01-01

    Department of Defense Recovery personnel and spacecraft technicians from NASA adn McDonnell Aircraft Corp., inspect Astronaut John Glenn's Mercury spacecraft, Friendship 7, following its return to Cape Canaveral after recovery in the Atlantic Ocean.

  14. High-Performance Fire Detector for Spacecraft, Phase I

    National Aeronautics and Space Administration — The danger from fire aboard spacecraft is immediate with only moments for detection and suppression. Spacecraft are unique high-value systems where the cost of...

  15. Development of Micro-Resolution PIV and Analysis of Microthrusters for Small-Scale Aircraft and Spacecraft

    Meinhart, Carl

    2000-01-01

    This research program consisted of two primary research objectives that were aimed at advancing the current understanding of microfluidic processes related to the development of small-scale aircraft and spacecraft. (1...

  16. Space tribology: its role in spacecraft mechanisms

    Roberts, E W

    2012-01-01

    The subject of tribology encompasses the friction, wear and lubrication of mechanical components such as bearings and gears. Tribological practices are aimed at ensuring that such components operate with high efficiency (low friction) and achieve long lives. On spacecraft mechanisms the route to achieving these goals brings its own unique challenges. This review describes the problems posed by the space environment, the types of tribological component used on spacecraft and the approaches taken to their lubrication. It is shown that in many instances lubrication needs can be met by synthetic oils having exceedingly low volatilities, but that at temperature extremes the only means of reducing friction and wear is by solid lubrication. As the demands placed on space engineering increase, innovatory approaches will be needed to solve future tribological problems. The direction that future developments might take is anticipated and discussed.

  17. MIDN: A spacecraft Micro-dosimeter mission

    Pisacane, V. L.; Ziegler, J. F.; Nelson, M. E.; Caylor, M.; Flake, D.; Heyen, L.; Youngborg, E.; Rosenfeld, A. B.; Cucinotta, F.; Zaider, M.; Dicello, J. F.

    2006-01-01

    MIDN (Micro-dosimetry instrument) is a payload on the MidSTAR-I spacecraft (Midshipman Space Technology Applications Research) under development at the United States Naval Academy. MIDN is a solid-state system being designed and constructed to measure Micro-dosimetric spectra to determine radiation quality factors for space environments. Radiation is a critical threat to the health of astronauts and to the success of missions in low-Earth orbit and space exploration. The system will consist of three separate sensors, one external to the spacecraft, one internal and one embedded in polyethylene. Design goals are mass <3 kg and power <2 W. The MidSTAR-I mission in 2006 will provide an opportunity to evaluate a preliminary version of this system. Its low power and mass makes it useful for the International Space Station and manned and unmanned interplanetary missions as a real-time system to assess and alert astronauts to enhanced radiation environments. (authors)

  18. Galileo spacecraft power management and distribution system

    Detwiler, R.C.; Smith, R.L.

    1990-01-01

    It has been twelve years since two Voyager spacecraft began the direct route to the outer planets. In October 1989 a single Galileo spacecraft started the return to Jupiter. Conceived as a simple Voyager look-alike, the Galileo power management and distribution (PMAD) system has undergone many iterations in configuration. Major changes to the PMAD resulted from dual spun slip ring limitations, variations in launch vehicle thrust capabilities, and launch delays. Lack of an adequate launch vehicle for an interplanetary mission of Galileo's size has resulted in an extremely long flight duration. A Venus-Earth-Earth Gravity Assist (VEEGA) tour, vital to attain the required energy, results in a 6 year trip to Jupiter and its moons. This paper provides a description of the Galileo PMAD and documents the design drivers that established the final as-built hardware

  19. Improved techniques for predicting spacecraft power

    Chmielewski, A.B.

    1987-01-01

    Radioisotope Thermoelectric Generators (RTGs) are going to supply power for the NASA Galileo and Ulysses spacecraft now scheduled to be launched in 1989 and 1990. The duration of the Galileo mission is expected to be over 8 years. This brings the total RTG lifetime to 13 years. In 13 years, the RTG power drops more than 20 percent leaving a very small power margin over what is consumed by the spacecraft. Thus it is very important to accurately predict the RTG performance and be able to assess the magnitude of errors involved. The paper lists all the error sources involved in the RTG power predictions and describes a statistical method for calculating the tolerance

  20. Data combinations accounting for LISA spacecraft motion

    Shaddock, Daniel A.; Tinto, Massimo; Estabrook, Frank B.; Armstrong, J.W.

    2003-01-01

    The laser interferometer space antenna is an array of three spacecraft in an approximately equilateral triangle configuration which will be used as a low-frequency gravitational wave detector. We present here new generalizations of the Michelson- and Sagnac-type time-delay interferometry data combinations. These combinations cancel laser phase noise in the presence of different up and down propagation delays in each arm of the array, and slowly varying systematic motion of the spacecraft. The gravitational wave sensitivities of these generalized combinations are the same as previously computed for the stationary cases, although the combinations are now more complicated. We introduce a diagrammatic representation to illustrate that these combinations are actually synthesized equal-arm interferometers

  1. The Stardust spacecraft arrives at KSC

    1998-01-01

    After arrival at the Shuttle Landing Facility in the early morning hours, the crated Stardust spacecraft waits to be unloaded from the aircraft. Built by Lockheed Martin Astronautics near Denver, Colo., for the Jet Propulsion Laboratory (JPL) NASA, the spacecraft Stardust will use a unique medium called aerogel to capture comet particles flying off the nucleus of comet Wild 2 in January 2004, plus collect interstellar dust for later analysis. Stardust will be launched aboard a Boeing Delta 7426 rocket from Complex 17, Cape Canaveral Air Station, targeted for Feb. 6, 1999. The collected samples will return to Earth in a re- entry capsule to be jettisoned from Stardust as it swings by in January 2006.

  2. Large Scale Experiments on Spacecraft Fire Safety

    Urban, David L.; Ruff, Gary A.; Minster, Olivier

    2012-01-01

    -based microgravity facilities or has been limited to very small fuel samples. Still, the work conducted to date has shown that fire behaviour in low-gravity is very different from that in normal-gravity, with differences observed for flammability limits, ignition delay, flame spread behaviour, flame colour and flame......Full scale fire testing complemented by computer modelling has provided significant knowhow about the risk, prevention and suppression of fire in terrestrial systems (cars, ships, planes, buildings, mines, and tunnels). In comparison, no such testing has been carried out for manned spacecraft due...... to the complexity, cost and risk associ-ated with operating a long duration fire safety experiment of a relevant size in microgravity. Therefore, there is currently a gap in knowledge of fire behaviour in spacecraft. The entire body of low-gravity fire research has either been conducted in short duration ground...

  3. FORTE spacecraft vibration mitigation. Final report

    Maly, J.R.

    1996-02-01

    This report documents work that was performed by CSA Engineering, Inc., for Los Alamos National Laboratory (LANL), to reduce vibrations of the FORTE spacecraft by retrofitting damped structural components into the spacecraft structure. The technical objective of the work was reduction of response at the location of payload components when the structure is subjected to the dynamic loading associated with launch and proto-qualification testing. FORTE is a small satellite that will be placed in orbit in 1996. The structure weighs approximately 425 lb, and is roughly 80 inches high and 40 inches in diameter. It was developed and built by LANL in conjunction with Sandia National Laboratories Albuquerque for the United States Department of Energy. The FORTE primary structure was fabricated primarily with graphite epoxy, using aluminum honeycomb core material for equipment decks and solar panel substrates. Equipment decks were bonded and bolted through aluminum mounting blocks to adjoining structure

  4. Redundancy for electric motors in spacecraft applications

    Smith, Robert J.; Flew, Alastair R.

    1986-01-01

    The parts of electric motors which should be duplicated in order to provide maximum reliability in spacecraft application are identified. Various common types of redundancy are described. The advantages and disadvantages of each are noted. The principal types are illustrated by reference to specific examples. For each example, constructional details, basic performance data and failure modes are described, together with a discussion of the suitability of particular redundancy techniques to motor types.

  5. Research on spacecraft electrical power conversion

    Wilson, T. G.

    1983-01-01

    The history of spacecraft electrical power conversion in literature, research and practice is reviewed. It is noted that the design techniques, analyses and understanding which were developed make today's contribution to power computers and communication installations. New applications which require more power, improved dynamic response, greater reliability, and lower cost are outlined. The switching mode approach in electronic power conditioning is discussed. Technical aspects of the research are summarized.

  6. Schema for Spacecraft-Command Dictionary

    Laubach, Sharon; Garcia, Celina; Maxwell, Scott; Wright, Jesse

    2008-01-01

    An Extensible Markup Language (XML) schema was developed as a means of defining and describing a structure for capturing spacecraft command- definition and tracking information in a single location in a form readable by both engineers and software used to generate software for flight and ground systems. A structure defined within this schema is then used as the basis for creating an XML file that contains command definitions.

  7. Wheel speed management control system for spacecraft

    Goodzeit, Neil E. (Inventor); Linder, David M. (Inventor)

    1991-01-01

    A spacecraft attitude control system uses at least four reaction wheels. In order to minimize reaction wheel speed and therefore power, a wheel speed management system is provided. The management system monitors the wheel speeds and generates a wheel speed error vector. The error vector is integrated, and the error vector and its integral are combined to form a correction vector. The correction vector is summed with the attitude control torque command signals for driving the reaction wheels.

  8. The Manned Spacecraft Center and medical technology

    Johnston, R. S.; Pool, S. L.

    1974-01-01

    A number of medically oriented research and hardware development programs in support of manned space flights have been sponsored by NASA. Blood pressure measuring systems for use in spacecraft are considered. In some cases, complete new bioinstrumentation systems were necessary to accomplish a specific physiological study. Plans for medical research during the Skylab program are discussed along with general questions regarding space-borne health service systems and details concerning the Health Services Support Control Center.

  9. Artificial Intelligence and Spacecraft Power Systems

    Dugel-Whitehead, Norma R.

    1997-01-01

    This talk will present the work which has been done at NASA Marshall Space Flight Center involving the use of Artificial Intelligence to control the power system in a spacecraft. The presentation will include a brief history of power system automation, and some basic definitions of the types of artificial intelligence which have been investigated at MSFC for power system automation. A video tape of one of our autonomous power systems using co-operating expert systems, and advanced hardware will be presented.

  10. THE FUTURE OF SPACECRAFT NUCLEAR PROPULSION

    Jansen, Frank

    2014-01-01

    This paper summarizes the advantages of space nuclear power and propulsion systems. It describes the actual status of international power level dependent spacecraft nuclear propulsion missions, especially the high power EU-Russian MEGAHIT study including the Russian Megawatt-Class Nuclear Power Propulsion System, the NASA GRC project and the low and medium power EU DiPoP study. Space nuclear propulsion based mission scenarios of these studies are sketched as well.

  11. 25 CFR 1000.70 - What criteria will the Director use to rank the applications and how many maximum points can be...

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false What criteria will the Director use to rank the applications and how many maximum points can be awarded for each criterion? 1000.70 Section 1000.70 Indians... Process § 1000.70 What criteria will the Director use to rank the applications and how many maximum points...

  12. Spacecraft early design validation using formal methods

    Bozzano, Marco; Cimatti, Alessandro; Katoen, Joost-Pieter; Katsaros, Panagiotis; Mokos, Konstantinos; Nguyen, Viet Yen; Noll, Thomas; Postma, Bart; Roveri, Marco

    2014-01-01

    The size and complexity of software in spacecraft is increasing exponentially, and this trend complicates its validation within the context of the overall spacecraft system. Current validation methods are labor-intensive as they rely on manual analysis, review and inspection. For future space missions, we developed – with challenging requirements from the European space industry – a novel modeling language and toolset for a (semi-)automated validation approach. Our modeling language is a dialect of AADL and enables engineers to express the system, the software, and their reliability aspects. The COMPASS toolset utilizes state-of-the-art model checking techniques, both qualitative and probabilistic, for the analysis of requirements related to functional correctness, safety, dependability and performance. Several pilot projects have been performed by industry, with two of them having focused on the system-level of a satellite platform in development. Our efforts resulted in a significant advancement of validating spacecraft designs from several perspectives, using a single integrated system model. The associated technology readiness level increased from level 1 (basic concepts and ideas) to early level 4 (laboratory-tested)

  13. Determination of Realistic Fire Scenarios in Spacecraft

    Dietrich, Daniel L.; Ruff, Gary A.; Urban, David

    2013-01-01

    This paper expands on previous work that examined how large a fire a crew member could successfully survive and extinguish in the confines of a spacecraft. The hazards to the crew and equipment during an accidental fire include excessive pressure rise resulting in a catastrophic rupture of the vehicle skin, excessive temperatures that burn or incapacitate the crew (due to hyperthermia), carbon dioxide build-up or accumulation of other combustion products (e.g. carbon monoxide). The previous work introduced a simplified model that treated the fire primarily as a source of heat and combustion products and sink for oxygen prescribed (input to the model) based on terrestrial standards. The model further treated the spacecraft as a closed system with no capability to vent to the vacuum of space. The model in the present work extends this analysis to more realistically treat the pressure relief system(s) of the spacecraft, include more combustion products (e.g. HF) in the analysis and attempt to predict the fire spread and limiting fire size (based on knowledge of terrestrial fires and the known characteristics of microgravity fires) rather than prescribe them in the analysis. Including the characteristics of vehicle pressure relief systems has a dramatic mitigating effect by eliminating vehicle overpressure for all but very large fires and reducing average gas-phase temperatures.

  14. Probing interferometric parallax with interplanetary spacecraft

    Rodeghiero, G.; Gini, F.; Marchili, N.; Jain, P.; Ralston, J. P.; Dallacasa, D.; Naletto, G.; Possenti, A.; Barbieri, C.; Franceschini, A.; Zampieri, L.

    2017-07-01

    We describe an experimental scenario for testing a novel method to measure distance and proper motion of astronomical sources. The method is based on multi-epoch observations of amplitude or intensity correlations between separate receiving systems. This technique is called Interferometric Parallax, and efficiently exploits phase information that has traditionally been overlooked. The test case we discuss combines amplitude correlations of signals from deep space interplanetary spacecraft with those from distant galactic and extragalactic radio sources with the goal of estimating the interplanetary spacecraft distance. Interferometric parallax relies on the detection of wavefront curvature effects in signals collected by pairs of separate receiving systems. The method shows promising potentialities over current techniques when the target is unresolved from the background reference sources. Developments in this field might lead to the construction of an independent, geometrical cosmic distance ladder using a dedicated project and future generation instruments. We present a conceptual overview supported by numerical estimates of its performances applied to a spacecraft orbiting the Solar System. Simulations support the feasibility of measurements with a simple and time-saving observational scheme using current facilities.

  15. On-orbit supervisor for controlling spacecraft

    Vandervoort, Richard J.

    1992-07-01

    Spacecraft systems of the 1990's and beyond will be substantially more complex than their predecessors. They will have demanding performance requirements and will be expected to operate more autonomously. This underscores the need for innovative approaches to Fault Detection, Isolation and Recovery (FDIR). A hierarchical expert system is presented that provides on-orbit supervision using intelligent FDIR techniques. Each expert system in the hierarchy supervises the operation of a local set of spacecraft functions. Spacecraft operational goals flow top down while responses flow bottom up. The expert system supervisors have a fairly high degree of autonomy. Bureaucratic responsibilities are minimized to conserve bandwidth and maximize response time. Data for FDIR can be acquired local to an expert and from other experts. By using a blackboard architecture for each supervisor, the system provides a great degree of flexibility in implementing the problem solvers for each problem domain. In addition, it provides for a clear separation between facts and knowledge, leading to an efficient system capable of real time response.

  16. Delamination Assessment Tool for Spacecraft Composite Structures

    Portela, Pedro; Preller, Fabian; Wittke, Henrik; Sinnema, Gerben; Camanho, Pedro; Turon, Albert

    2012-07-01

    Fortunately only few cases are known where failure of spacecraft structures due to undetected damage has resulted in a loss of spacecraft and launcher mission. However, several problems related to damage tolerance and in particular delamination of composite materials have been encountered during structure development of various ESA projects and qualification testing. To avoid such costly failures during development, launch or service of spacecraft, launcher and reusable launch vehicles structures a comprehensive damage tolerance verification approach is needed. In 2009, the European Space Agency (ESA) initiated an activity called “Delamination Assessment Tool” which is led by the Portuguese company HPS Lda and includes academic and industrial partners. The goal of this study is the development of a comprehensive damage tolerance verification approach for launcher and reusable launch vehicles (RLV) structures, addressing analytical and numerical methodologies, material-, subcomponent- and component testing, as well as non-destructive inspection. The study includes a comprehensive review of current industrial damage tolerance practice resulting from ECSS and NASA standards, the development of new Best Practice Guidelines for analysis, test and inspection methods and the validation of these with a real industrial case study. The paper describes the main findings of this activity so far and presents a first iteration of a Damage Tolerance Verification Approach, which includes the introduction of novel analytical and numerical tools at an industrial level. This new approach is being put to the test using real industrial case studies provided by the industrial partners, MT Aerospace, RUAG Space and INVENT GmbH

  17. Space Transportation System Cargo projects: inertial stage/spacecraft integration plan. Volume 1: Management plan

    1981-01-01

    The Kennedy Space Center (KSC) Management System for the Inertial Upper Stage (IUS) - spacecraft processing from KSC arrival through launch is described. The roles and responsibilities of the agencies and test team organizations involved in IUS-S/C processing at KSC for non-Department of Defense missions are described. Working relationships are defined with respect to documentation preparation, coordination and approval, schedule development and maintenance, test conduct and control, configuration management, quality control and safety. The policy regarding the use of spacecraft contractor test procedures, IUS contractor detailed operating procedures and KSC operations and maintenance instructions is defined. Review and approval requirements for each documentation system are described.

  18. Los directores aprendiendo de sus maestros

    Manuel Ortega Muñoz

    2016-07-01

    Full Text Available El presente artículo de investigación está enmarcado dentro de la línea de indagación Aprendizaje para la Gestión y versa sobre los principales aprendizajes que han adquirido los directivos de educación básica del estado de Durango, México, para el mejor ejercicio de su función. Desde un estudio de narrativa, se recopilaron historias de 16 directores de educación primaria estatal pertenecientes a la zona escolar 24 del sector educativo no. 1 de la Secretaría de Educación Pública. El análisis de los datos se llevó a cabo mediante la herramienta de análisis de información cualitativa Atlas ti versión 7.5. Los hallazgos de la investigación muestran que los principales aprendizajes que los directivos de educación básica del estado de Durango, México han adquirido de sus maestros para el mejor ejercicio de su función son dos: a el trabajo en equipo, del cual se desprenden componentes como una eficaz y eficiente organización del trabajo, el trabajar siempre en colaboración y tener la mejor de las actitudes para trabajar; y b el liderazgo compartido, aspecto en que se perciben elementos como el óptimo manejo y resolución de conflictos, el liderazgo y la toma de decisiones en conjunto por parte del colectivo escolar. Abstract This research paper, framed within the line of inquiry Learning Management, deals with the main lessons that have acquired the management of basic education in the state of Durango, Mexico, for the best performance of their duties, from a study of narrative histories of 16 directors of state primary education outside the school zone 24 the education sector 1 of the Ministry of Education. The data analysis was performed using the computer statistical package you Atlas ti version 7.5. The research findings show that there are two main lessons that have acquired the management of basic education in the state of Durango, Mexico from their teachers for the better performance of their function: a teamwork

  19. Modes of uncontrolled rotational motion of the Progress M-29M spacecraft

    Belyaev, M. Yu.; Matveeva, T. V.; Monakhov, M. I.; Rulev, D. N.; Sazonov, V. V.

    2018-01-01

    We have reconstructed the uncontrolled rotational motion of the Progress M-29M transport cargo spacecraft in the single-axis solar orientation mode (the so-called sunward spin) and in the mode of the gravitational orientation of a rotating satellite. The modes were implemented on April 3-7, 2016 as a part of preparation for experiments with the DAKON convection sensor onboard the Progress spacecraft. The reconstruction was performed by integral statistical techniques using the measurements of the spacecraft's angular velocity and electric current from its solar arrays. The measurement data obtained in a certain time interval have been jointly processed using the least-squares method by integrating the equations of the spacecraft's motion relative to the center of mass. As a result of processing, the initial conditions of motion and parameters of the mathematical model have been estimated. The motion in the sunward spin mode is the rotation of the spacecraft with an angular velocity of 2.2 deg/s about the normal to the plane of solar arrays; the normal is oriented toward the Sun or forms a small angle with this direction. The duration of the mode is several orbit passes. The reconstruction has been performed over time intervals of up to 1 h. As a result, the actual rotational motion of the spacecraft relative to the Earth-Sun direction was obtained. In the gravitational orientation mode, the spacecraft was rotated about its longitudinal axis with an angular velocity of 0.1-0.2 deg/s; the longitudinal axis executed small oscillated relative to the local vertical. The reconstruction of motion relative to the orbital coordinate system was performed in time intervals of up to 7 h using only the angularvelocity measurements. The measurements of the electric current from solar arrays were used for verification.

  20. Space Environments and Spacecraft Effects Organization Concept

    Edwards, David L.; Burns, Howard D.; Miller, Sharon K.; Porter, Ron; Schneider, Todd A.; Spann, James F.; Xapsos, Michael

    2012-01-01

    The National Aeronautics and Space Administration (NASA) is embarking on a course to expand human presence beyond Low Earth Orbit (LEO) while also expanding its mission to explore the solar system. Destinations such as Near Earth Asteroids (NEA), Mars and its moons, and the outer planets are but a few of the mission targets. Each new destination presents an opportunity to increase our knowledge of the solar system and the unique environments for each mission target. NASA has multiple technical and science discipline areas specializing in specific space environments disciplines that will help serve to enable these missions. To complement these existing discipline areas, a concept is presented focusing on the development of a space environments and spacecraft effects (SENSE) organization. This SENSE organization includes disciplines such as space climate, space weather, natural and induced space environments, effects on spacecraft materials and systems and the transition of research information into application. This space environment and spacecraft effects organization will be composed of Technical Working Groups (TWG). These technical working groups will survey customers and users, generate products, and provide knowledge supporting four functional areas: design environments, engineering effects, operational support, and programmatic support. The four functional areas align with phases in the program mission lifecycle and are briefly described below. Design environments are used primarily in the mission concept and design phases of a program. Engineering effects focuses on the material, component, sub-system and system-level selection and the testing to verify design and operational performance. Operational support provides products based on real time or near real time space weather to mission operators to aid in real time and near-term decision-making. The programmatic support function maintains an interface with the numerous programs within NASA, other federal

  1. Large Scale Experiments on Spacecraft Fire Safety

    Urban, David; Ruff, Gary A.; Minster, Olivier; Fernandez-Pello, A. Carlos; Tien, James S.; Torero, Jose L.; Legros, Guillaume; Eigenbrod, Christian; Smirnov, Nickolay; Fujita, Osamu; hide

    2012-01-01

    Full scale fire testing complemented by computer modelling has provided significant knowhow about the risk, prevention and suppression of fire in terrestrial systems (cars, ships, planes, buildings, mines, and tunnels). In comparison, no such testing has been carried out for manned spacecraft due to the complexity, cost and risk associated with operating a long duration fire safety experiment of a relevant size in microgravity. Therefore, there is currently a gap in knowledge of fire behaviour in spacecraft. The entire body of low-gravity fire research has either been conducted in short duration ground-based microgravity facilities or has been limited to very small fuel samples. Still, the work conducted to date has shown that fire behaviour in low-gravity is very different from that in normal gravity, with differences observed for flammability limits, ignition delay, flame spread behaviour, flame colour and flame structure. As a result, the prediction of the behaviour of fires in reduced gravity is at present not validated. To address this gap in knowledge, a collaborative international project, Spacecraft Fire Safety, has been established with its cornerstone being the development of an experiment (Fire Safety 1) to be conducted on an ISS resupply vehicle, such as the Automated Transfer Vehicle (ATV) or Orbital Cygnus after it leaves the ISS and before it enters the atmosphere. A computer modelling effort will complement the experimental effort. Although the experiment will need to meet rigorous safety requirements to ensure the carrier vehicle does not sustain damage, the absence of a crew removes the need for strict containment of combustion products. This will facilitate the possibility of examining fire behaviour on a scale that is relevant to spacecraft fire safety and will provide unique data for fire model validation. This unprecedented opportunity will expand the understanding of the fundamentals of fire behaviour in spacecraft. The experiment is being

  2. Family and Provider/Teacher Relationship Quality: Director Measure

    Administration for Children & Families, 2015

    2015-01-01

    The director measure is intended for use with program directors in center-based, family child care, and Head Start/Early Head Start settings for children from birth through five years old. This measure asks respondents general questions about the early childhood education environment, the children enrolled in the program, and how the program…

  3. Do Director Networks Help Manager Plan and Forecast Better?

    Schabus, M.

    I examine whether directors' superior access to information and resources through their board network improves the quality of firms' planning and forecasting. Managers may benefit from well-connected directors as, even though managers have firm specific knowledge, they may have only limited insight

  4. Veterinary Technician Program Director Leadership Style and Program Success

    Renda-Francis, Lori A.

    2012-01-01

    Program directors of American Veterinary Medical Association (AVMA) accredited veterinary technician programs may have little or no training in leadership. The need for program directors of AVMA-accredited veterinary technician programs to understand how leadership traits may have an impact on student success is often overlooked. The purpose of…

  5. 7 CFR 2.36 - Director, Office of Communications.

    2010-01-01

    ... are made by the Secretary of Agriculture to Director, Office of Communications: (1) Related to public...) Organize and direct the activities of a public affairs office to include press relations of the secretary... 7 Agriculture 1 2010-01-01 2010-01-01 false Director, Office of Communications. 2.36 Section 2.36...

  6. 50 CFR 11.13 - Decision by the Director.

    2010-10-01

    ... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Decision by the Director. 11.13 Section 11..., POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS CIVIL PROCEDURES Assessment Procedure § 11.13 Decision by the Director. Upon expiration of the period required or...

  7. Food Recall Attitudes and Behaviors of School Nutrition Directors

    Grisamore, Amber; Roberts, Kevin R.

    2014-01-01

    Purpose/Objectives: The purpose of this study was to explore school nutrition directors' attitudes and behaviors about food recalls. Specific objectives included: 1) Determine current food recall attitudes and the relationship between demographics and these attitudes; 2) Determine current practices of school nutrition directors related to…

  8. 78 FR 69927 - SJI Board of Directors Meeting, Notice

    2013-11-21

    ... STATE JUSTICE INSTITUTE SJI Board of Directors Meeting, Notice AGENCY: State Justice Institute. ACTION: Notice of meeting. SUMMARY: The SJI Board of Directors will be meeting on Monday, December 9, 2013 at 1:00 p.m. The meeting will be held at the 9th Judicial Circuit of Florida in Orlando, Florida...

  9. The Managerial Roles of Academic Library Directors: The Mintzberg Model.

    Moskowitz, Michael Ann

    1986-01-01

    A study based on a model developed by Henry Mintzberg examined the internal and external managerial roles of 126 New England college and university library directors. Survey results indicate that the 97 responding directors were primarily involved with internal managerial roles and work contacts. (CDD)

  10. Continuous director-field transformation of nematic tactoids

    Prinsen, P.; Schoot, van der P.P.A.M.

    2004-01-01

    We theoretically investigate the director field inside spindle-shaped nematic droplets, known as tactoids. Tactoids typically form in dispersions of rod-like colloidal particles. By optimising the bulk elastic and surface energies, we find that the director field crosses over smoothly from a

  11. Examining the concept of de facto director in corporate governance

    Anthony O. Nwafor

    2016-07-01

    Full Text Available There are different categories of persons involved in the execution of the company’s affairs, but not all have the capacity to bind the company as the embodiment of the company itself. Those who exercise acts of management and control over the company’s business are usually referred to as the directors. Where persons who satisfy the statutorily prescribed qualification standard are duly appointed by the shareholders to exercise control and manage the affairs of the company function in that capacity, they are usually identified as de jure directors. But where there is no such appointment, or irregular appointment, the law demands, for the protection of those dealing with the company, that the role performed by the person be examined to ascertain whether such a person is a de facto director. The more difficult part lies in identifying a de facto director where the subject company has a corporate body as its director. The extant judicial authority suggests that the human person in the corporate director must be performing functions which are beyond the natural call of duty in relation to the corporate director to constitute a de facto director of the subject company. The paper argues that the standard is satisfied in any case where the human person is involved in the initiation and execution of the affairs of the subject company, and more so where the conducts of the subject company are patently unlawful.

  12. 76 FR 58303 - Regular Board of Directors Meeting; Sunshine Act

    2011-09-20

    ..., Washington, DC 20005. STATUS: Open. CONTACT PERSON FOR MORE INFORMATION: Erica Hall, Assistant Corporate... Directors Minutes III. Approval of the Special Board of Directors Minutes IV. Approval of the Corporate Administration Committee Minutes V. Approval of the Finance, Budget and Program Committee Minutes VI. Approval of...

  13. 19 CFR 146.2 - Port director as Board representative.

    2010-04-01

    ...; DEPARTMENT OF THE TREASURY (CONTINUED) FOREIGN TRADE ZONES General Provisions § 146.2 Port director as Board representative. The appropriate port director shall be in charge of the zone as the representative of the Board. [T.D. 86-16, 51 FR 5049, Feb. 11, 1986, as amended by T.D. 99-27, 64 FR 13676, Mar. 22, 1999] ...

  14. Creating the Vision: Directors Don't Do It Alone.

    Carlisle, Barbara; Drapeau, Don

    1997-01-01

    Argues that good directors are not as autocratic and individualistic as they are often portrayed. Suggests that theater is much more of an ensemble effort. States that good theater grows out of the performers' desire to reach the audience. Articulates guidelines for the teacher or theater director who wishes to change "I" to…

  15. CEA nuclear energy Directorate - Activity report 2012

    2013-01-01

    After an overview of the activities of the Directorate at the international level, of its scientific activities, and of the consideration given to quality, and a presentation of the transverse program on advanced materials, this report proposes presentations of activities in different domains: future nuclear industrial systems (reactors of 4. generation, back-end of the future cycle, sustainable management of nuclear materials, fundamental scientific and technological research), optimization of the present industrial nuclear activity (reactors of 2. and 3. generation, front-end and back-end of the fuel cycle), the main tools for nuclear development (numerical simulation, the Jules Horowitz reactor), valorisation, economic support of Haute-Marne and Meuse territories (the Syndiese project), nuclear dismantling and decontamination (dismantling projects, projects and works in Fontenay-aux-Roses, Grenoble and Saclay, waste and material flow management, nuclear service facilities, transports). It also presents the activities of some specific CEA centres like Marcoule (R and D in fuel cycle), Cadarache (future energies) and Saclay (nuclear sciences and simulation of reactors and fuel cycle)

  16. JSC Director's Discretionary Fund 1992 Annual Report

    Jenkins, Lyle (Compiler)

    1993-01-01

    Annual report of the Johnson Space Center Director's Discretionary Fund documenting effective use of resources. The $1,694,000 funding for FY92 was distributed among 27 projects. The projects are an overall aid to the NASA mission, as well as providing development opportunities for the science and engineering staff with eventual spinoff to commercial uses. Projects described include space-based medical research such as the use of stable isotopes of deuterium and oxygen to measure crew energy use and techniques for noninvasive motion sickness medication. Recycling essentials for space crew support is conducted in the Regenerative Life Support and the Hybrid Regenerative Water Recovery test beds. Two-phase fluid flow simulated under low-gravity conditions, hypervelocity particle impact on open mesh bumpers, and microcalorimetry to measure the long-term hydrazine/material compatibility were investigated. A patent application was made on a shape-memory-alloy release nut. Computer estimate of crew accommodations for advanced concepts was demonstrated. Training techniques were evaluated using multimedia and virtual environment. Upgrades of an electronic still camera provide high resolution images from orbit are presented.

  17. A spacecraft's own ambient environment: The role of simulation-based research

    Ketsdever, Andrew D. [University of Colorado Colorado Springs, Department of Mechanical and Aerospace Engineering, Colorado Springs, CO (United States); Gimelshein, Sergey [University of Southern California, Department of Astronautical Engineering, Los Angeles, CA (United States)

    2014-12-09

    Spacecraft contamination has long been a subject of study in the rarefied gas dynamics community. Professor Mikhail Ivanov coined the term a spacecraft's 'own ambient environment' to describe the effects of natural and satellite driven processes on the conditions encountered by a spacecraft in orbit. Outgassing, thruster firings, and gas and liquid dumps all contribute to the spacecraft's contamination environment. Rarefied gas dynamic modeling techniques, such as Direct Simulation Monte Carlo, are well suited to investigate these spacebased environments. However, many advances were necessary to fully characterize the extent of this problem. A better understanding of modeling flows over large pressure ranges, for example hybrid continuum and rarefied numerical schemes, were required. Two-phase flow modeling under rarefied conditions was necessary. And the ability to model plasma flows for a new era of propulsion systems was also required. Through the work of Professor Ivanov and his team, we now have a better understanding of processes that create a spacecraft's own ambient environment and are able to better characterize these environments. Advances in numerical simulation have also spurred on the development of experimental facilities to study these effects. The relationship between numerical results and experimental advances will be explored in this manuscript.

  18. The long-term benefits of director stock ownership

    Brian Bolton

    2009-11-01

    Full Text Available In October 2009, the United States Treasury Department and Congress considered new regulations requiring executives and directors to receive much of their compensation in the form of long-term stock. One concern with this is that it may have negative consequences by entrenching managers and directors over the long term. This study compares the potential benefits of long-term director ownership with the potential costs of entrenchment. Using the dollar amount of stock owned by independent directors, the results suggest that the incentive effect dominates any costs related to entrenchment: firms with greater stock ownership outperform other firms, regardless of the degree of managerial entrenchment that may be present. The implication for policy-makers is that providing directors with incentives through stock ownership can be a very effective corporate governance mechanism.

  19. Director Experience and the Performance of IPOs: Evidence from Sweden

    Anders Isaksson

    2014-03-01

    Full Text Available private to public. In this paper the experience of directors is examined to determine the extent of the role they play in ensuring a successful listing. Unique data from 122 IPOs on the Swedish Stock Exchange have been examined in a search for the effect of director experience on aftermarket performance. Specific aspects of director experience within a board, such as interlocking directorships and average tenure, are connected to the underpricing of Swedish IPOs. Contrary to expectations, no statistically significant relationship was found between long-run aftermarket performance and director experience at the time of an IPO. This suggests that the previous experience of directors, as measured in earlier studies, is less relevant to long-term aftermarket performance in Sweden compared to other countries studied in the literature review. This emphasises the importance of examining different institutional contexts.

  20. Characteristics of CEOs and corporate boards with women inside directors

    Deborah Dahlen Zelechowski

    2006-07-01

    Full Text Available Women corporate inside (executive directors constitute an elite minority of leaders of large corporations. This study examines the characteristics of CEOs and boards of Fortune 1000 firms that had women who held the dual leadership positions of corporate director and executive officer in 1998 in order to determine whether firms with women insiders had substantially different characteristics than firms without. We find that compared with firms without women inside directors, firms with women inside directors were characterized by CEOs with longer board tenure, more family ties, and fewer director interlocks, and by boards that were larger, with more insiders, and that utilize a management Chair of the board. Corporate governance implications are drawn for the presence of women at the top of the executive hierarchy.

  1. Auditor’s Risk Assessment of Independent Directors in Nigeria

    Salau Abdulmalik

    2017-01-01

    Full Text Available The objective of this study is to investigate the external auditor’s risk assessment of independent directors in Nigeria. The study utilized data from 94 non-financial listed companies on the Nigerian Stock Exchange for the periods 2008-2013. The study used cross-sectional time-series feasible generalized least square regression, which account for heteroscedasticity and autocorrelation to test the influence independent non-executive director on auditor pricing decision in Nigeria. Our result indicates that the proportion of independent non-executive director has a positive relationship with audit fees, suggesting that this class of directors is priced high by the Nigerian auditors. These findings have both policy and practical implication on corporate governance. For instance, future regulatory reforms could consider collaborative board model instead of the insistence on more independent director presence in the boardroom.

  2. Spacecraft Charging: Hazard Causes, Hazard Effects, Hazard Controls

    Koontz, Steve.

    2018-01-01

    Spacecraft flight environments are characterized both by a wide range of space plasma conditions and by ionizing radiation (IR), solar ultraviolet and X-rays, magnetic fields, micrometeoroids, orbital debris, and other environmental factors, all of which can affect spacecraft performance. Dr. Steven Koontz's lecture will provide a solid foundation in the basic engineering physics of spacecraft charging and charging effects that can be applied to solving practical spacecraft and spacesuit engineering design, verification, and operations problems, with an emphasis on spacecraft operations in low-Earth orbit, Earth's magnetosphere, and cis-Lunar space.

  3. Comprehensive Fault Tolerance and Science-Optimal Attitude Planning for Spacecraft Applications

    Nasir, Ali

    Spacecraft operate in a harsh environment, are costly to launch, and experience unavoidable communication delay and bandwidth constraints. These factors motivate the need for effective onboard mission and fault management. This dissertation presents an integrated framework to optimize science goal achievement while identifying and managing encountered faults. Goal-related tasks are defined by pointing the spacecraft instrumentation toward distant targets of scientific interest. The relative value of science data collection is traded with risk of failures to determine an optimal policy for mission execution. Our major innovation in fault detection and reconfiguration is to incorporate fault information obtained from two types of spacecraft models: one based on the dynamics of the spacecraft and the second based on the internal composition of the spacecraft. For fault reconfiguration, we consider possible changes in both dynamics-based control law configuration and the composition-based switching configuration. We formulate our problem as a stochastic sequential decision problem or Markov Decision Process (MDP). To avoid the computational complexity involved in a fully-integrated MDP, we decompose our problem into multiple MDPs. These MDPs include planning MDPs for different fault scenarios, a fault detection MDP based on a logic-based model of spacecraft component and system functionality, an MDP for resolving conflicts between fault information from the logic-based model and the dynamics-based spacecraft models" and the reconfiguration MDP that generates a policy optimized over the relative importance of the mission objectives versus spacecraft safety. Approximate Dynamic Programming (ADP) methods for the decomposition of the planning and fault detection MDPs are applied. To show the performance of the MDP-based frameworks and ADP methods, a suite of spacecraft attitude planning case studies are described. These case studies are used to analyze the content and

  4. Studies of Fission Fragment Rocket Engine Propelled Spacecraft

    Werka, Robert O.; Clark, Rodney; Sheldon, Rob; Percy, Thomas K.

    2014-01-01

    The NASA Office of Chief Technologist has funded from FY11 through FY14 successive studies of the physics, design, and spacecraft integration of a Fission Fragment Rocket Engine (FFRE) that directly converts the momentum of fission fragments continuously into spacecraft momentum at a theoretical specific impulse above one million seconds. While others have promised future propulsion advances if only you have the patience, the FFRE requires no waiting, no advances in physics and no advances in manufacturing processes. Such an engine unequivocally can create a new era of space exploration that can change spacecraft operation. The NIAC (NASA Institute for Advanced Concepts) Program Phase 1 study of FY11 first investigated how the revolutionary FFRE technology could be integrated into an advanced spacecraft. The FFRE combines existent technologies of low density fissioning dust trapped electrostatically and high field strength superconducting magnets for beam management. By organizing the nuclear core material to permit sufficient mean free path for escape of the fission fragments and by collimating the beam, this study showed the FFRE could convert nuclear power to thrust directly and efficiently at a delivered specific impulse of 527,000 seconds. The FY13 study showed that, without increasing the reactor power, adding a neutral gas to the fission fragment beam significantly increased the FFRE thrust through in a manner analogous to a jet engine afterburner. This frictional interaction of gas and beam resulted in an engine that continuously produced 1000 pound force of thrust at a delivered impulse of 32,000 seconds, thereby reducing the currently studied DRM 5 round trip mission to Mars from 3 years to 260 days. By decreasing the gas addition, this same engine can be tailored for much lower thrust at much higher impulse to match missions to more distant destinations. These studies created host spacecraft concepts configured for manned round trip journeys. While the

  5. Structural Dynamic Analyses And Test Predictions For Spacecraft Structures With Non-Linearities

    Vergniaud, Jean-Baptiste; Soula, Laurent; Newerla, Alfred

    2012-07-01

    The overall objective of the mechanical development and verification process is to ensure that the spacecraft structure is able to sustain the mechanical environments encountered during launch. In general the spacecraft structures are a-priori assumed to behave linear, i.e. the responses to a static load or dynamic excitation, respectively, will increase or decrease proportionally to the amplitude of the load or excitation induced. However, past experiences have shown that various non-linearities might exist in spacecraft structures and the consequences of their dynamic effects can significantly affect the development and verification process. Current processes are mainly adapted to linear spacecraft structure behaviour. No clear rules exist for dealing with major structure non-linearities. They are handled outside the process by individual analysis and margin policy, and analyses after tests to justify the CLA coverage. Non-linearities can primarily affect the current spacecraft development and verification process on two aspects. Prediction of flights loads by launcher/satellite coupled loads analyses (CLA): only linear satellite models are delivered for performing CLA and no well-established rules exist how to properly linearize a model when non- linearities are present. The potential impact of the linearization on the results of the CLA has not yet been properly analyzed. There are thus difficulties to assess that CLA results will cover actual flight levels. Management of satellite verification tests: the CLA results generated with a linear satellite FEM are assumed flight representative. If the internal non- linearities are present in the tested satellite then there might be difficulties to determine which input level must be passed to cover satellite internal loads. The non-linear behaviour can also disturb the shaker control, putting the satellite at risk by potentially imposing too high levels. This paper presents the results of a test campaign performed in

  6. Research-Based Monitoring, Prediction, and Analysis Tools of the Spacecraft Charging Environment for Spacecraft Users

    Zheng, Yihua; Kuznetsova, Maria M.; Pulkkinen, Antti A.; Maddox, Marlo M.; Mays, Mona Leila

    2015-01-01

    The Space Weather Research Center (http://swrc. gsfc.nasa.gov) at NASA Goddard, part of the Community Coordinated Modeling Center (http://ccmc.gsfc.nasa.gov), is committed to providing research-based forecasts and notifications to address NASA's space weather needs, in addition to its critical role in space weather education. It provides a host of services including spacecraft anomaly resolution, historical impact analysis, real-time monitoring and forecasting, tailored space weather alerts and products, and weekly summaries and reports. In this paper, we focus on how (near) real-time data (both in space and on ground), in combination with modeling capabilities and an innovative dissemination system called the integrated Space Weather Analysis system (http://iswa.gsfc.nasa.gov), enable monitoring, analyzing, and predicting the spacecraft charging environment for spacecraft users. Relevant tools and resources are discussed.

  7. The Rosetta Mission - Where no Spacecraft has gone before

    CERN. Geneva

    2015-01-01

    This Talk will provide an overview on the Scientific Highlights of the Rosetta Mission. After travelling through the Solar System for nearly 10 years Rosetta arrived at its main target, Comet 67/P Churyumov-Gerasimenko, in August 2014. Following an initial characterisation of the Comet, the lander unit Philae touched down on the partly active Nucleus on November 12 of the same year. The data acquired from the numerous instruments onboard the Spacecraft provides a unique insight into the properties of the Comets. While most of the measurements and processing of the data are still ongoing, the results from the Mission provide continuous surprises to the scientific community. While the Lander has been reactivated with some difficulties after a few months of inactivity due to low insolation levels, the Orbiter is pursuing its main mission objectives until the end of its extended Mission in Autumn 2016. During the long journey, the Spacecraft had encountered Earth, Mars and two Asteroids ( 2867 Šteins and 21 Lu...

  8. Cluster PEACE observations of electrons of spacecraft origin

    S. Szita

    2001-09-01

    Full Text Available The two PEACE (Plasma Electron And Current Experiment sensors on board each Cluster spacecraft sample the electron velocity distribution across the full 4 solid angle and the energy range 0.7 eV to 26 keV with a time resolution of 4 s. We present high energy and angular resolution 3D observations of electrons of spacecraft origin in the various environments encountered by the Cluster constellation, including a lunar eclipse interval where the spacecraft potential was reduced but remained positive, and periods of ASPOC (Active Spacecraft POtential Control operation which reduced the spacecraft potential. We demonstrate how the spacecraft potential may be found from a gradient change in the PEACE low energy spectrum, and show how the observed spacecraft electrons are confined by the spacecraft potential. We identify an intense component of the spacecraft electrons with energies equivalent to the spacecraft potential, the arrival direction of which is seen to change when ASPOC is switched on. Another spacecraft electron component, observed in the sunward direction, is reduced in the eclipse but unaffected by ASPOC, and we believe this component is produced in the analyser by solar UV. We find that PEACE anodes with a look direction along the spacecraft surfaces are more susceptible to spacecraft electron contamination than those which look perpendicular to the surface, which justifies the decision to mount PEACE with its field-of-view radially outward rather than tangentially.Key words. Magnetosheric physics (general or miscellaneous Space plasma physics (spacecraft sheaths, wakes, charging

  9. Spacecraft systems engineering: An introduction to the process at GSFC

    Fragomeni, Tony; Ryschkewitsch, Michael G.

    1993-01-01

    The main objective in systems engineering is to devise a coherent total system design capable of achieving the stated requirements. Requirements should be rigid. However, they should be continuously challenged, rechallenged and/or validated. The systems engineer must specify every requirement in order to design, document, implement and conduct the mission. Each and every requirement must be logically considered, traceable and evaluated through various analysis and trade studies in a total systems design. Margins must be determined to be realistic as well as adequate. The systems engineer must also continuously close the loop and verify system performance against the requirements. The fundamental role of the systems engineer, however, is to engineer, not manage. Yet, in large, complex missions, where more than one systems engineer is required, someone needs to manage the systems engineers, and we call them 'systems managers.' Systems engineering management is an overview function which plans, guides, monitors and controls the technical execution of a project as implemented by the systems engineers. As the project moves on through Phases A and B into Phase C/D, the systems engineering tasks become a small portion of the total effort. The systems management role increases since discipline subsystem engineers are conducting analyses and reviewing test data for final review and acceptance by the systems managers.

  10. Spacecraft fabrication and test MODIL. Final report

    Saito, T.T.

    1994-05-01

    This report covers the period from October 1992 through the close of the project. FY 92 closed out with the successful briefing to industry and with many potential and important initiatives in the spacecraft arena. Due to the funding uncertainties, we were directed to proceed as if our funding would be approximately the same as FY 92 ($2M), but not to make any major new commitments. However, the MODIL`s FY 93 funding was reduced to $810K and we were directed to concentrate on the cryocooler area. The cryocooler effort completed its demonstration project. The final meetings with the cryocooler fabricators were very encouraging as we witnessed the enthusiastic reception of technology to help them reduce fabrication uncertainties. Support of the USAF Phillips Laboratory cryocooler program was continued including kick-off meetings for the Prototype Spacecraft Cryocooler (PSC). Under Phillips Laboratory support, Gill Cruz visited British Aerospace and Lucas Aerospace in the United Kingdom to assess their manufacturing capabilities. In the Automated Spacecraft & Assembly Project (ASAP), contracts were pursued for the analysis by four Brilliant Eyes prime contractors to provide a proprietary snap shot of their current status of Integrated Product Development. In the materials and structure thrust the final analysis was completed of the samples made under the contract (``Partial Automation of Matched Metal Net Shape Molding of Continuous Fiber Composites``) to SPARTA. The Precision Technologies thrust funded the Jet Propulsion Laboratory to prepare a plan to develop a Computer Aided Alignment capability to significantly reduce the time for alignment and even possibly provide real time and remote alignment capability of systems in flight.

  11. Soyuz Spacecraft Transported to Launch Pad

    2003-01-01

    The Soyuz TMA-3 spacecraft and its booster rocket (rear view) is shown on a rail car for transport to the launch pad where it was raised to a vertical launch position at the Baikonur Cosmodrome, Kazakhstan on October 16, 2003. Liftoff occurred on October 18th, transporting a three man crew to the International Space Station (ISS). Aboard were Michael Foale, Expedition-8 Commander and NASA science officer; Alexander Kaleri, Soyuz Commander and flight engineer, both members of the Expedition-8 crew; and European Space agency (ESA) Astronaut Pedro Duque of Spain. Photo Credit: 'NASA/Bill Ingalls'

  12. Effects of Spacecraft Landings on the Moon

    Metzger, Philip T.; Lane, John E.

    2013-01-01

    The rocket exhaust of spacecraft landing on the Moon causes a number of observable effects that need to be quantified, including: disturbance of the regolith and volatiles at the landing site; damage to surrounding hardware such as the historic Apollo sites through the impingement of high-velocity ejecta; and levitation of dust after engine cutoff through as-yet unconfirmed mechanisms. While often harmful, these effects also beneficially provide insight into lunar geology and physics. Some of the research results from the past 10 years is summarized and reviewed here.

  13. Fault Detection and Isolation for Spacecraft

    Jensen, Hans-Christian Becker; Wisniewski, Rafal

    2002-01-01

    This article realizes nonlinear Fault Detection and Isolation for actuators, given there is no measurement of the states in the actuators. The Fault Detection and Isolation of the actuators is instead based on angular velocity measurement of the spacecraft and knowledge about the dynamics...... of the satellite. The algorithms presented in this paper are based on a geometric approach to achieve nonlinear Fault Detection and Isolation. The proposed algorithms are tested in a simulation study and the pros and cons of the algorithms are discussed....

  14. Aircraft, ships, spacecraft, nuclear plants and quality

    Patrick, M.G.

    1984-05-01

    A few quality assurance programs outside the purview of the Nuclear Regulatory Commission were studied to identify features or practices which the NRC could use to enhance its program for assuring quality in the design and construction of nuclear power plants. The programs selected were: the manufacture of large commercial transport aircraft, regulated by the Federal Aviation Administration; US Navy shipbuilding; commercial shipbuilding regulated by the Maritime Administration and the US Coast Guard; Government-owned nuclear plants under the Department of Energy; spacecraft under the National Aeronautics and Space Administration; and the construction of nuclear power plants in Canada, West Germany, France, Japan, Sweden, and the United Kingdom

  15. SSS-A spacecraft and experiment description.

    Longanecker, G. W.; Hoffman, R. A.

    1973-01-01

    The scientific objectives of the Explorer-45 mission are discussed. The primary objective is the study of the ring current responsible for the main phase of magnetic storms. Closely associated with this objective is the determination of the relationship between magnetic storms, substorms, and the acceleration of charged particles in the magnetosphere. Further objectives are the measurement of a wide range of proton, electron and alpha-particle energies, and studies of wave-particle interactions responsible for particle transport and loss in the inner magnetosphere. The orbital parameters, the spacecraft itself, and some of its unique features, such as the data handling system, which is programmable from the ground, are described.

  16. SOME CONSIDERATIONS REGARDING THE REVOCATION OF THE COMPANY DIRECTOR

    Cristina Cojocaru

    2013-11-01

    Full Text Available In principle, in Romania, according to current regulations, the director of a company can not address the court against the decision of the general meeting of shareholders through which he/she was revoked from his/her position, regardless of the reasons for the revocation. However, if the director is also the shareholder of that company, he/she may appeal the decision of the general meeting of shareholders, for other reasons than the revocation itself. This is the case even if, by that decision of the general meeting of shareholders it has been decided, inter alia, the revocation of the director. Also, the laws of Romania stipulate that the revoked director has the possibility to claim in court damages if he/she fulfilled correctly the duties as director of the company. At the same time, the article looks at the concept of director, his/her relations with the company and the revocation of the director as general concept.

  17. Director and Officer Liability in the Zone of Insolvency; A Comparative Analysis

    HH Rajak

    2008-04-01

    Full Text Available It is the duty of the directors of a company to run the business of the company in the best interests of the company and its shareholders. In principle, the company, alone, is responsible for the debts incurred in the running of the company and the creditors are, in principle, precluded from looking to the directors or shareholders for payment of any shortfall arising as a result of the company's insolvency. This principle has, in a number of jurisdictions undergone statutory change such that in certain circumstances, the directors and others who were concerned with the management of the company may be made liable to contribute, personally, to meet the payment – in part or entirely – of the company's debts. This paper aims to explore this statutory jurisdiction. It also seeks to describe succinctly the process by which the shift from unlimited to limited liability trading was achieved. It will end by examining briefly a comparatively new phenomenon, namely that of a shift in the focus of the directors' duties from company and shareholders to the creditors as the company becomes insolvent and nears the stage of a formal declaration of its insolvent status – the so-called 'zone of insolvency'.

  18. Simulation of Tomographic Reconstruction of Magnetosphere Plasma Distribution By Multi-spacecraft Systems.

    Kunitsyn, V.; Nesterov, I.; Andreeva, E.; Zelenyi, L.; Veselov, M.; Galperin, Y.; Buchner, J.

    A satellite radiotomography method for electron density distributions was recently proposed for closely-space multi-spacecraft group of high-altitude satellites to study the physics of reconnection process. The original idea of the ROY project is to use a constellation of spacecrafts (one main and several sub-satellites) in order to carry out closely-spaced multipoint measurements and 2D tomographic reconstruction of elec- tron density in the space between the main satellite and the subsatellites. The distances between the satellites were chosen to vary from dozens to few hundreds of kilometers. The easiest data interpretation is achieved when the subsatellites are placed along the plasma streamline. Then, whenever a plasma density irregularity moves between the main satellite and the subsatellites it will be scanned in different directions and we can get 2D distribution of plasma using these projections. However in general sub- satellites are not placed exactly along the plasma streamline. The method of plasma velocity determination relative to multi-spacecraft systems is considered. Possibilities of 3D tomographic imaging using multi-spacecraft systems are analyzed. The model- ing has shown that efficient scheme for 3D tomographic imaging would be to place spacecrafts in different planes so that the angle between the planes would make not more then ten degrees. Work is supported by INTAS PROJECT 2000-465.

  19. Nonlinear model and attitude dynamics of flexible spacecraft with large amplitude slosh

    Deng, Mingle; Yue, Baozeng

    2017-04-01

    This paper is focused on the nonlinearly modelling and attitude dynamics of spacecraft coupled with large amplitude liquid sloshing dynamics and flexible appendage vibration. The large amplitude fuel slosh dynamics is included by using an improved moving pulsating ball model. The moving pulsating ball model is an equivalent mechanical model that is capable of imitating the whole liquid reorientation process. A modification is introduced in the capillary force computation in order to more precisely estimate the settling location of liquid in microgravity or zero-g environment. The flexible appendage is modelled as a three dimensional Bernoulli-Euler beam and the assumed modal method is employed to derive the nonlinear mechanical model for the overall coupled system of liquid filled spacecraft with appendage. The attitude maneuver is implemented by the momentum transfer technique, and a feedback controller is designed. The simulation results show that the liquid sloshing can always result in nutation behavior, but the effect of flexible deformation of appendage depends on the amplitude and direction of attitude maneuver performed by spacecraft. Moreover, it is found that the liquid sloshing and the vibration of flexible appendage are coupled with each other, and the coupling becomes more significant with more rapid motion of spacecraft. This study reveals that the appendage's flexibility has influence on the liquid's location and settling time in microgravity. The presented nonlinear system model can provide an important reference for the overall design of the modern spacecraft composed of rigid platform, liquid filled tank and flexible appendage.

  20. Identifying areas of weakness in thoracic surgery residency training: a comparison of the perceptions of residents and program directors.

    Edwards, Janet P; Schofield, Adam; Paolucci, Elizabeth Oddone; Schieman, Colin; Kelly, Elizabeth; Servatyari, Ramin; Dixon, Elijah; Ball, Chad G; Grondin, Sean C

    2014-01-01

    To identify core thoracic surgery procedures that require increased emphasis during thoracic surgery residency for residents to achieve operative independence and to compare the perspectives of residents and program directors in this regard. A modified Delphi process was used to create a survey that was distributed electronically to all Canadian thoracic surgery residents (12) and program directors (8) addressing the residents' ability to perform 19 core thoracic surgery procedures independently after the completion of residency. Residents were also questioned about the adequacy of their operative exposure to these 19 procedures during their residency training. A descriptive summary including calculations of frequencies and proportions was conducted. The perceptions of the 2 groups were then compared using the Fisher exact test employing a Bonferroni correction. The relationship between residents' operative exposure and their perceived operative ability was explored in the same fashion. The response rate was 100% for residents and program directors. No statistical differences were found between residents' and program directors' perceptions of residents' ability to perform the 19 core procedures independently. Both groups identified lung transplantation, first rib resection, and extrapleural pneumonectomy as procedures for which residents were not adequately prepared to perform independently. Residents' subjective ratings of operative exposure were in good agreement with their reported operative ability for 13 of 19 procedures. This study provides new insight into the perceptions of thoracic surgery residents and their program directors regarding operative ability. This study points to good agreement between residents and program directors regarding residents' surgical capabilities. This study provides information regarding potential weaknesses in thoracic surgery training, which may warrant an examination of the curricula of existing programs as well as a

  1. Small Rocket/Spacecraft Technology (SMART) Platform

    Esper, Jaime; Flatley, Thomas P.; Bull, James B.; Buckley, Steven J.

    2011-01-01

    The NASA Goddard Space Flight Center (GSFC) and the Department of Defense Operationally Responsive Space (ORS) Office are exercising a multi-year collaborative agreement focused on a redefinition of the way space missions are designed and implemented. A much faster, leaner and effective approach to space flight requires the concerted effort of a multi-agency team tasked with developing the building blocks, both programmatically and technologically, to ultimately achieve flights within 7-days from mission call-up. For NASA, rapid mission implementations represent an opportunity to find creative ways for reducing mission life-cycle times with the resulting savings in cost. This in tum enables a class of missions catering to a broader audience of science participants, from universities to private and national laboratory researchers. To that end, the SMART (Small Rocket/Spacecraft Technology) micro-spacecraft prototype demonstrates an advanced avionics system with integrated GPS capability, high-speed plug-and-playable interfaces, legacy interfaces, inertial navigation, a modular reconfigurable structure, tunable thermal technology, and a number of instruments for environmental and optical sensing. Although SMART was first launched inside a sounding rocket, it is designed as a free-flyer.

  2. Time delay interferometry with moving spacecraft arrays

    Tinto, Massimo; Estabrook, F.B.; Armstrong, J.W.

    2004-01-01

    Space-borne interferometric gravitational wave detectors, sensitive in the low-frequency (millihertz) band, will fly in the next decade. In these detectors the spacecraft-to-spacecraft light-travel-times will necessarily be unequal, time varying, and (due to aberration) have different time delays on up and down links. The reduction of data from moving interferometric laser arrays in solar orbit will in fact encounter nonsymmetric up- and down-link light time differences that are about 100 times larger than has previously been recognized. The time-delay interferometry (TDI) technique uses knowledge of these delays to cancel the otherwise dominant laser phase noise and yields a variety of data combinations sensitive to gravitational waves. Under the assumption that the (different) up- and down-link time delays are constant, we derive the TDI expressions for those combinations that rely only on four interspacecraft phase measurements. We then turn to the general problem that encompasses time dependence of the light-travel times along the laser links. By introducing a set of noncommuting time-delay operators, we show that there exists a quite general procedure for deriving generalized TDI combinations that account for the effects of time dependence of the arms. By applying our approach we are able to re-derive the 'flex-free' expression for the unequal-arm Michelson combinations X 1 , and obtain the generalized expressions for the TDI combinations called relay, beacon, monitor, and symmetric Sagnac

  3. Relativistic effects of spacecraft with circumnavigating observer

    Shanklin, Nathaniel; West, Joseph

    A variation of the recently introduced Trolley Paradox, itself is a variation of the Ehrenfest Paradox is presented. In the Trolley Paradox, a ``stationary'' set of observers tracking a wheel rolling with a constant velocity find that the wheel travels further than its rest length circumference during one revolution of the wheel, despite the fact that the Lorentz contracted circumference is less than its rest value. In the variation presented, a rectangular spacecraft with onboard observers moves with constant velocity and is circumnavigated by several small ``sloops'' forming teams of inertial observers. This whole precession moves relative to a set of ``stationary'' Earth observers. Two cases are presented, one in which the sloops are evenly spaced according to the spacecraft observers, and one in which the sloops are evenly spaced according to the Earth observes. These two cases, combined with the rectangular geometry and an emphasis on what is seen by, and what is measured by, each set of observers is very helpful in sorting out the apparent contradictions. To aid in the visualizations stationary representations in excel along with animation in Visual Python and Unity are presented. The analysis presented is suitable for undergraduate physics majors.

  4. Spacecraft Dynamic Characterization by Strain Energies Method

    Bretagne, J.-M.; Fragnito, M.; Massier, S.

    2002-01-01

    In the last years the significant increase in satellite broadcasting demand, with the wide band communication dawn, has given a great impulse to the telecommunication satellite market. The big demand is translated from operators (such as SES/Astra, Eutelsat, Intelsat, Inmarsat, EuroSkyWay etc.) in an increase of orders of telecom satellite to the world industrials. The largest part of these telecom satellite orders consists of Geostationary platforms which grow more and more in mass (over 5 tons) due to an ever longer demanded lifetime (up to 20 years), and become more complex due to the need of implementing an ever larger number of repeaters, antenna reflectors and feeds, etc... In this frame, the mechanical design and verification of these large spacecraft become difficult and ambitious at the same time, driven by the dry mass limitation objective. By the Finite Element Method (FEM), and on the basis of the telecom satellite heritage of a world leader constructor such as Alcatel Space Industries it is nowadays possible to model these spacecraft in a realistic and confident way in order to identify the main global dynamic aspects such as mode shapes, mass participation and/or dynamic responses. But on the other hand, one of the main aims consists in identifying soon in a program the most critical aspects of the system behavior in the launch dynamic environment, such as possible dynamic coupling between the different subsystems and secondary structures of the spacecraft (large deployable reflectors, thrusters, etc.). To this aim a numerical method has been developed in the frame of the Alcatel SPACEBUS family program, using MSC/Nastran capabilities and it is presented in this paper. The method is based on Spacecraft sub-structuring and strain energy calculation. The method mainly consists of two steps : 1) subsystem modal strain energy ratio (with respect to the global strain energy); 2) subsystem strain energy calculation for each mode according to the base driven

  5. Large-Scale Spacecraft Fire Safety Experiments in ISS Resupply Vehicles

    Ruff, Gary A.; Urban, David

    2013-01-01

    Our understanding of the fire safety risk in manned spacecraft has been limited by the small scale of the testing we have been able to conduct in low-gravity. Fire growth and spread cannot be expected to scale linearly with sample size so we cannot make accurate predictions of the behavior of realistic scale fires in spacecraft based on the limited low-g testing to date. As a result, spacecraft fire safety protocols are necessarily very conservative and costly. Future crewed missions are expected to be longer in duration than previous exploration missions outside of low-earth orbit and accordingly, more complex in terms of operations, logistics, and safety. This will increase the challenge of ensuring a fire-safe environment for the crew throughout the mission. Based on our fundamental uncertainty of the behavior of fires in low-gravity, the need for realistic scale testing at reduced gravity has been demonstrated. To address this concern, a spacecraft fire safety research project is underway to reduce the uncertainty and risk in the design of spacecraft fire safety systems by testing at nearly full scale in low-gravity. This project is supported by the NASA Advanced Exploration Systems Program Office in the Human Exploration and Operations Mission Directorate. The activity of this project is supported by an international topical team of fire experts from other space agencies to maximize the utility of the data and to ensure the widest possible scrutiny of the concept. The large-scale space flight experiment will be conducted on three missions; each in an Orbital Sciences Corporation Cygnus vehicle after it has deberthed from the ISS. Although the experiment will need to meet rigorous safety requirements to ensure the carrier vehicle does not sustain damage, the absence of a crew allows the fire products to be released into the cabin. The tests will be fully automated with the data downlinked at the conclusion of the test before the Cygnus vehicle reenters the

  6. Optimal Weighting of Multi-Spacecraft Data to Estimate Gradients of Physical Fields

    Chanteur, G. M.; Le Contel, O.; Sahraoui, F.; Retino, A.; Mirioni, L.

    2016-12-01

    Multi-spacecraft missions like the ESA mission CLUSTER and the NASA mission MMS are essential to improve our understanding of physical processes in space plasmas. Several methods were designed in the 90's during the preparation phase of the CLUSTER mission to estimate gradients of physical fields from simultaneous multi-points measurements [1, 2]. Both CLUSTER and MMS involve four spacecraft with identical full scientific payloads including various sensors of electromagnetic fields and different type of particle detectors. In the standard methods described in [1, 2], which are presently in use, data from the four spacecraft have identical weights and the estimated gradients are most reliable when the tetrahedron formed by the four spacecraft is regular. There are three types of errors affecting the estimated gradients (see chapter 14 in [1]) : i) truncature errors are due to local non-linearity of spatial variations, ii) physical errors are due to instruments, and iii) geometrical errors are due to uncertainties on the positions of the spacecraft. An assessment of truncature errors for a given observation requires a theoretical model of the measured field. Instrumental errors can easily be taken into account for a given geometry of the cluster but are usually less than the geometrical errors which diverge quite fast when the tetrahedron flattens, a circumstance occurring twice per orbit of the cluster. Hence reliable gradients can be estimated only on part of the orbit. Reciprocal vectors of the tetrahedron were presented in chapter 4 of [1], they have the advantage over other methods to treat the four spacecraft symmetrically and to allow a theoretical analysis of the errors (see chapters 4 of [1] and 4 of [2]). We will present Generalized Reciprocal Vectors for weighted data and an optimization procedure to improve the reliability of the estimated gradients when the tetrahedron is not regular. A brief example using CLUSTER or MMS data will be given. This approach

  7. The Glory Program: Global Science from a Unique Spacecraft Integration

    Bajpayee Jaya; Durham, Darcie; Ichkawich, Thomas

    2006-01-01

    The Glory program is an Earth and Solar science mission designed to broaden science community knowledge of the environment. The causes and effects of global warming have become a concern in recent years and Glory aims to contribute to the knowledge base of the science community. Glory is designed for two functions: one is solar viewing to monitor the total solar irradiance and the other is observing the Earth s atmosphere for aerosol composition. The former is done with an active cavity radiometer, while the latter is accomplished with an aerosol polarimeter sensor to discern atmospheric particles. The Glory program is managed by NASA Goddard Space Flight Center (GSFC) with Orbital Sciences in Dulles, VA as the prime contractor for the spacecraft bus, mission operations, and ground system. This paper will describe some of the more unique features of the Glory program including the integration and testing of the satellite and instruments as well as the science data processing. The spacecraft integration and test approach requires extensive analysis and additional planning to ensure existing components are successfully functioning with the new Glory components. The science mission data analysis requires development of mission unique processing systems and algorithms. Science data analysis and distribution will utilize our national assets at the Goddard Institute for Space Studies (GISS) and the University of Colorado's Laboratory for Atmospheric and Space Physics (LASP). The Satellite was originally designed and built for the Vegetation Canopy Lidar (VCL) mission, which was terminated in the middle of integration and testing due to payload development issues. The bus was then placed in secure storage in 2001 and removed from an environmentally controlled container in late 2003 to be refurbished to meet the Glory program requirements. Functional testing of all the components was done as a system at the start of the program, very different from a traditional program

  8. Osiris-REx Spacecraft Current Status and Forward Plans

    Messenger, Scott; Lauretta, Dante S.; Connolly, Harold C., Jr.

    2017-01-01

    with which the navigation team can deliver the spacecraft to and from specific sites on the asteroid surface. The Sampleability map quantifies the regolith properties, providing an estimation of how much material would be sampled at different points on the surface. The final Science Value map synthesizes the chemical, mineralogical, and geological, observations to identify the areas of the asteroid surface with the highest science value. Here, priority is given to organic, water-rich regions that have been minimally altered by surface processes. Asteroid surface samples will be acquired with a touch-and-go sample acquisition system (TAGSAM) that uses high purity pressurized N2 gas to mobilize regolith into a stainless steel canister. Although the mission requirement is to collect at least 60 g of material, tests of the TAGSAM routinely exceeded 300 g of simulant in micro-gravity tests. After acquiring the sample, the spacecraft will depart Bennu in 2021 to begin its return journey, with the sample return capsule landing at the Utah Test and Training Range on September 23, 2023. The OSIRIS-REx science team will carry out a series of detailed chemical, mineralogical, isotopic, and spectral studies that will be used to determine the origin and history of Bennu and to relate high spatial resolution sample studies to the global geological context from remote sensing. The outline of the sample analysis plan is described in a companion abstract.

  9. REP activities of the conference of radiation control program directors

    Bevill, B.

    1995-01-01

    This talk provides an overview of the activities within the Conference of Radiation Control Program Directors associated with Radiological Emergency Preparedness. Included are summaries of interactions with FEMA, with US DOE, with US FDA, and with US DOT

  10. Dr. William C. Harris, Director-General, Science Foundation Ireland

    Maximilien Brice

    2002-01-01

    Pictured with Robert Eisenstein, former assistant director for mathematical and physical sciences (MPS) at the US National Science Foundation (NSF), who is spending a year at CERN as a member of the ATLAS collaboration.

  11. 75 FR 67380 - Office of the Director; Notice of Meeting

    2010-11-02

    ... of Outside Awards for ACD Approval; Biomedical Workforce Issues; ACD Stem Cell Working Group Report...: 8 a.m. to 3 p.m. Agenda: NIH Director's Report, Lasker Clinical Research Program; ACD TRND Working...

  12. 12 CFR 611.210 - Director qualifications and training.

    2010-01-01

    ... periodically updated and provided to the institution's nominating committee. (2) Each Farm Credit institution... advisor who is a financial expert. The financial advisor must report to the board of directors and be free...

  13. Llewellyn Smith, Director-General designate of CERN, discusses LHC

    Sweet, William N

    1992-01-01

    Christopher Llewellyn Smith was nominated by the Committee of Council to be Director General of CERN. He aims to pave the way for the Large Hadron Collider and utilize to the full the Large Electron-Positron machine.

  14. CERN stop-over for KEK and Fermilab Directors

    2001-01-01

    En route for a meeting of the International Committee for Future Accelerators, ICFA, held at Germany's DESY laboratory, the Directors of Japan's KEK laboratory and Fermilab in the United States had a stop-over at CERN last Wednesday 7 February. Dr Hirotaka Sugawara, Director General of Japan's high energy physics laboratory, KEK, visited the Antiproton Decelerator, AD. From left to right, Masaki Hori, member of the ASACUSA collaboration, John Eades, contact person for ASACUSA, Dr Hirotaka Sugawara, Werner Pirkl, the PS Division engineer responsible for the Radio Frequency Quadrupole decelerator in the foreground, and Kurt Hübner, CERN's Director of Accelerators. Dr Michael S. Witherell, Director of the Fermi National Accelerator Laboratory, Fermilab, visited construction sites for the LHC, ATLAS, and CMS. He is seen here with a module of the CMS hadronic calorimeter in building 186.

  15. Juan Antonio Rubio appointed as Director-General of CIEMAT

    2004-01-01

    Juan Antonio Rubio, Head of CERN's ETT unit (Education and Technology Transfer) has been appointed by the Spanish Ministry of Education and Science as the Director General of the Research Centre for Energy, Environment and Technology, CIEMAT. Dr Rubio's career began at the Spanish Nuclear Energy Commission where he held the posts of Investigator, Head of the High Energy Group and Head of Nuclear Physics and High Energy Division. Later, he was named Director of the Department of Basic Investigation and Scientific Director of the CIEMAT. In 1987 he joined CERN as Scientific Adviser to the Director General and Group Leader of the Scientific Assessment Group. Up to now, Dr Rubio has been the Head of the ETT unit, as well as Coordinator for Latin America and Commissioner for the 50th Anniversary of the Organization. He was born on 4 June 1944 in Madrid, and holds a Doctorate in Physical Sciences from the Universidad Complutense de Madrid.

  16. 22 CFR 67.2 - Board of Directors.

    2010-04-01

    ..., Washington, DC 20005-5000. (b) All major policy and funding decisions are made by the Board of Directors. The primary statement of NED's operating philosophy, general principles and priorities is contained in the...

  17. Female Directors and Firm Performance: Evidence from UK Listed Firms

    Pananda Pasaribu

    2017-08-01

    Full Text Available The impact of female directors on firm performance has lacked consistency in the previously conducted empirical studies, which may be due to the endogeneity problem, or certain characteristics (i.e. governance, industry, competition. This study examines the relationship between female directors and firm performance by addressing those problems. This study analyses all non-financial UK listed firms during the period 2004-2012 and employs several econometric models. The regression results indicate that there is little evidence that female directors have a positive and strong relationship with firm performance. But, further analysis reports that the UK’s small listed firms experience a positive significant effect, because small firms do not suffer from the problem of over-monitoring and they have more flexibility in composing their boards of directors.

  18. Thomas Sinks, Director, Office of the Science Advisor

    Biography of the Director of the Office of the Science Advisor which is responsible for is responsible for EPA’s human subject research ethics, scientific integrity, and developing cross-agency science policy guidance.

  19. Institute for Advanced Learning and Research names new executive director

    Virginia Tech News

    2008-01-01

    Virginia Tech's Institute for Advanced Learning and Research has named Liam E. Leightley as executive director, effective Oct. 6, 2008, according to Mike Henderson, chair of the institute's board of trustees.

  20. NREL Manager Elected to IREC Board of Directors

    Manager Elected to IREC Board of Directors For more information contact: Sarah Holmes Barba, 303 -275-3023 email: Sarah Barba Golden, Colo., May 14, 2001 - David Warner, manager of the Information and

  1. On spacecraft maneuvers control subject to propellant engine modes.

    Mazinan, A H

    2015-09-01

    The paper attempts to address a new control approach to spacecraft maneuvers based upon the modes of propellant engine. A realization of control strategy is now presented in engine on mode (high thrusts as well as further low thrusts), which is related to small angle maneuvers and engine off mode (specified low thrusts), which is also related to large angle maneuvers. There is currently a coarse-fine tuning in engine on mode. It is shown that the process of handling the angular velocities are finalized via rate feedback system in engine modes, where the angular rotations are controlled through quaternion based control (QBCL)strategy in engine off mode and these ones are also controlled through an optimum PID (OPIDH) strategy in engine on mode. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  2. Spacecraft Dynamics Should be Considered in Kalman Filter Attitude Estimation

    Yang, Yaguang; Zhou, Zhiqiang

    2016-01-01

    Kalman filter based spacecraft attitude estimation has been used in some high-profile missions and has been widely discussed in literature. While some models in spacecraft attitude estimation include spacecraft dynamics, most do not. To our best knowledge, there is no comparison on which model is a better choice. In this paper, we discuss the reasons why spacecraft dynamics should be considered in the Kalman filter based spacecraft attitude estimation problem. We also propose a reduced quaternion spacecraft dynamics model which admits additive noise. Geometry of the reduced quaternion model and the additive noise are discussed. This treatment is more elegant in mathematics and easier in computation. We use some simulation example to verify our claims.

  3. Electromagnetic Forces on a Relativistic Spacecraft in the Interstellar Medium

    Hoang, Thiem [Korea Astronomy and Space Science Institute, Daejeon 34055 (Korea, Republic of); Loeb, Abraham, E-mail: thiemhoang@kasi.re.kr, E-mail: aloeb@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA (United States)

    2017-10-10

    A relativistic spacecraft of the type envisioned by the Breakthrough Starshot initiative will inevitably become charged through collisions with interstellar particles and UV photons. Interstellar magnetic fields would therefore deflect the trajectory of the spacecraft. We calculate the expected deflection for typical interstellar conditions. We also find that the charge distribution of the spacecraft is asymmetric, producing an electric dipole moment. The interaction between the moving electric dipole and the interstellar magnetic field is found to produce a large torque, which can result in fast oscillation of the spacecraft around the axis perpendicular to the direction of motion, with a period of ∼0.5 hr. We then study the spacecraft rotation arising from impulsive torques by dust bombardment. Finally, we discuss the effect of the spacecraft rotation and suggest several methods to mitigate it.

  4. Independent Directors and Stakeholders Protection: A Case of Sime Darby

    Prashanth Beleya; Gopalan Raman; Charles Ramendren; Suresh Nodeson

    2012-01-01

    In today’s ever challenging corporate environment, the unfortunate events of decision making by top management has led major companies to suffer huge losses. This results and mistakes made have given a significant impact to the stake holder’s perception and raise a serious questions on the role of board of directors especially the role of independent directors. In today’s fast evolving business pace with stiff economic conditions, unethical and misjudgment in business decisions are driving th...

  5. A practitioner’s research: Director remuneration in Ukraine

    Alexander N. Kostyuk

    2006-07-01

    Full Text Available Remuneration of members of the supervisory boards in Ukrainian joint-stock companies is the most controversial issue of the corporate board practices. Despite the firm belief of the shareholders that the director remuneration is one of the most important factors influencing the board performance, there are still many companies (21 per cent where directors are not remunerated for their work on the supervisory board. This report examines practices of the director’s remuneration in Ukraine.

  6. Female Directors and Firm Performance: Evidence from UK Listed Firms

    Pasaribu, Pananda

    2017-01-01

    The impact of female directors on firm performance has lacked consistency in the previously conducted empirical studies, which may be due to the endogeneity problem, or certain characteristics (i.e. governance, industry, competition). This study examines the relationship between female directors and firm performance by addressing those problems. This study analyses all non-financial UK listed firms during the period 2004-2012 and employs several econometric models. The regression results indi...

  7. El Consejero Dominical y el Gobierno Corporativo / Institutional Directors and Corporate Governance

    Chiva Ortells, Carlos

    2017-01-01

    The aim of this research is to study the role of institutional directors in corporate governance. For this purpose, we have analysed the impact that these directors have on CEO compensation and on corporate social responsibility disclosure. Moreover, institutional directors have been classified into two groups: pressure-resistant institutional directors and pressure-sensitive institutional directors. The results show that institutional directors, as a whole, and pressure-resistant institution...

  8. CEO Emotional Intelligence and Board of Directors Efficiency

    Mohamed Ali Azouzi

    2012-07-01

    Full Text Available This article deals with the relationship existing between the emotional aspect and decision-making processes. More specifically, it examines the links between emotional intelligence, decision biases and effectiveness of the governance mechanisms. The primary purposes of this article are to: consider emotional intelligence like new research ideas that make important contributions to society; offer suggestions for improving manuscripts submitted to the journal; and discuss methods for enhancing the validity of inferences made from research. The article explains that the main cause of organization’s problems is CEO emotional intelligence level. I will use three models (linear regression and logistic binary regression to examine this correlation: each model treats the relationship between emotional intelligence and one of efficiency criteria of the board. Emotional intelligence has been measured according to the Schutte self-report emotional intelligence scale with a high internal validity level. Regarding the four cognitive biases, they have been measured by means of a questionnaire comprising several items. As for the selected sample, it comprises of some one hundred and eighty Tunisian executives, belonging to sixty firms. Our results have revealed that the presence of a high emotional intelligence rate is not always positively correlated with the executives’ suggestibility with respect to behavioral biases. They have also affirmed the existence of a complementarity relationship between emotional intelligence and the board of directors.

  9. Application of advanced electronics to a future spacecraft computer design

    Carney, P. C.

    1980-01-01

    Advancements in hardware and software technology are summarized with specific emphasis on spacecraft computer capabilities. Available state of the art technology is reviewed and candidate architectures are defined.

  10. Addressing EO-1 Spacecraft Pulsed Plasma Thruster EMI Concerns

    Zakrzwski, C. M.; Davis, Mitch; Sarmiento, Charles; Bauer, Frank H. (Technical Monitor)

    2001-01-01

    The Pulsed Plasma Thruster (PPT) Experiment on the Earth Observing One (EO-1) spacecraft has been designed to demonstrate the capability of a new generation PPT to perform spacecraft attitude control. Results from PPT unit level radiated electromagnetic interference (EMI) tests led to concerns about potential interference problems with other spacecraft subsystems. Initial plans to address these concerns included firing the PPT at the spacecraft level both in atmosphere, with special ground support equipment. and in vacuum. During the spacecraft level tests, additional concerns where raised about potential harm to the Advanced Land Imager (ALI). The inadequacy of standard radiated emission test protocol to address pulsed electromagnetic discharges and the lack of resources required to perform compatibility tests between the PPT and an ALI test unit led to changes in the spacecraft level validation plan. An EMI shield box for the PPT was constructed and validated for spacecraft level ambient testing. Spacecraft level vacuum tests of the PPT were deleted. Implementation of the shield box allowed for successful spacecraft level testing of the PPT while eliminating any risk to the ALI. The ALI demonstration will precede the PPT demonstration to eliminate any possible risk of damage of ALI from PPT operation.

  11. Simulator Facility for Attitude Control and Energy Storage of Spacecraft

    Tsiotras, Panagiotis

    2002-01-01

    This report concerns a designed and built experimental facility that will allow the conduction of experiments for validating advanced attitude control algorithms for spacecraft in a weightless environment...

  12. Cometary dust size distributions from flyby spacecraft

    Divine, N.

    1988-01-01

    Pior to the Halley flybys in 1986, the distribution of cometary dust grains with particle size were approximated using models which provided reasonable fits to the dynamics of dust tails, anti-tails, and infrared spectra. These distributions have since been improved using fluence data (i.e., particle fluxes integrated over time along the flyby trajectory) from three spacecraft. The fluence derived distributions are appropriate for comparison with simultaneous infrared photometry (from Earth) because they sample the particles in the same way as the IR data do (along the line of sight) and because they are directly proportional to the concentration distribution in that region of the coma which dominates the IR emission

  13. A corrector for spacecraft calculated electron moments

    J. Geach

    2005-03-01

    Full Text Available We present the application of a numerical method to correct electron moments calculated on-board spacecraft from the effects of potential broadening and energy range truncation. Assuming a shape for the natural distribution of the ambient plasma and employing the scalar approximation, the on-board moments can be represented as non-linear integral functions of the underlying distribution. We have implemented an algorithm which inverts this system successfully over a wide range of parameters for an assumed underlying drifting Maxwellian distribution. The outputs of the solver are the corrected electron plasma temperature Te, density Ne and velocity vector Ve. We also make an estimation of the temperature anisotropy A of the distribution. We present corrected moment data from Cluster's PEACE experiment for a range of plasma environments and make comparisons with electron and ion data from other Cluster instruments, as well as the equivalent ground-based calculations using full 3-D distribution PEACE telemetry.

  14. Generating Animated Displays of Spacecraft Orbits

    Candey, Robert M.; Chimiak, Reine A.; Harris, Bernard T.

    2005-01-01

    Tool for Interactive Plotting, Sonification, and 3D Orbit Display (TIPSOD) is a computer program for generating interactive, animated, four-dimensional (space and time) displays of spacecraft orbits. TIPSOD utilizes the programming interface of the Satellite Situation Center Web (SSCWeb) services to communicate with the SSC logic and database by use of the open protocols of the Internet. TIPSOD is implemented in Java 3D and effects an extension of the preexisting SSCWeb two-dimensional static graphical displays of orbits. Orbits can be displayed in any or all of the following seven reference systems: true-of-date (an inertial system), J2000 (another inertial system), geographic, geomagnetic, geocentric solar ecliptic, geocentric solar magnetospheric, and solar magnetic. In addition to orbits, TIPSOD computes and displays Sibeck's magnetopause and Fairfield's bow-shock surfaces. TIPSOD can be used by the scientific community as a means of projection or interpretation. It also has potential as an educational tool.

  15. Planning Inmarsat's second generation of spacecraft

    Williams, W. P.

    1982-09-01

    The next generation of studies of the Inmarsat service are outlined, such as traffic forecasting studies, communications capacity estimates, space segment design, cost estimates, and financial analysis. Traffic forecasting will require future demand estimates, and a computer model has been developed which estimates demand over the Atlantic, Pacific, and Indian ocean regions. Communications estimates are based on traffic estimates, as a model converts traffic demand into a required capacity figure for a given area. The Erlang formula is used, requiring additional data such as peak hour ratios and distribution estimates. Basic space segment technical requirements are outlined (communications payload, transponder arrangements, etc), and further design studies involve such areas as space segment configuration, launcher and spacecraft studies, transmission planning, and earth segment configurations. Cost estimates of proposed design parameters will be performed, but options must be reduced to make construction feasible. Finally, a financial analysis will be carried out in order to calculate financial returns.

  16. Flight mission control for multiple spacecraft

    Ryan, Robert E.

    1990-10-01

    A plan developed by the Jet Propulsion Laboratory for mission control of unmanned spacecraft is outlined. A technical matrix organization from which, in the past, project teams were formed to uniquely support a mission is replaced in this new plan. A cost effective approach was needed to make best use of limited resources. Mission control is a focal point operations and a good place to start a multimission concept. Co-location and sharing common functions are the keys to obtaining efficiencies at minimum additional risk. For the projects, the major changes are sharing a common operations area and having indirect control of personnel. The plan identifies the still direct link for the mission control functions. Training is a major element in this plan. Personnel are qualified for a position and certified for a mission. This concept is more easily accepted by new missions than the ongoing missions.

  17. High Gain Antenna Calibration on Three Spacecraft

    Hashmall, Joseph A.

    2011-01-01

    This paper describes the alignment calibration of spacecraft High Gain Antennas (HGAs) for three missions. For two of the missions (the Lunar Reconnaissance Orbiter and the Solar Dynamics Observatory) the calibration was performed on orbit. For the third mission (the Global Precipitation Measurement core satellite) ground simulation of the calibration was performed in a calibration feasibility study. These three satellites provide a range of calibration situations-Lunar orbit transmitting to a ground antenna for LRO, geosynchronous orbit transmitting to a ground antenna fer SDO, and low Earth orbit transmitting to TDRS satellites for GPM The calibration results depend strongly on the quality and quantity of calibration data. With insufficient data the calibration Junction may give erroneous solutions. Manual intervention in the calibration allowed reliable parameters to be generated for all three missions.

  18. Human factors issues for interstellar spacecraft

    Cohen, Marc M.; Brody, Adam R.

    1991-01-01

    Developments in research on space human factors are reviewed in the context of a self-sustaining interstellar spacecraft based on the notion of traveling space settlements. Assumptions about interstellar travel are set forth addressing costs, mission durations, and the need for multigenerational space colonies. The model of human motivation by Maslow (1970) is examined and directly related to the design of space habitat architecture. Human-factors technology issues encompass the human-machine interface, crew selection and training, and the development of spaceship infrastructure during transtellar flight. A scenario for feasible instellar travel is based on a speed of 0.5c, a timeframe of about 100 yr, and an expandable multigenerational crew of about 100 members. Crew training is identified as a critical human-factors issue requiring the development of perceptual and cognitive aids such as expert systems and virtual reality.

  19. Rechargeable metal hydrides for spacecraft application

    Perry, J. L.

    1988-01-01

    Storing hydrogen on board the Space Station presents both safety and logistics problems. Conventional storage using pressurized bottles requires large masses, pressures, and volumes to handle the hydrogen to be used in experiments in the U.S. Laboratory Module and residual hydrogen generated by the ECLSS. Rechargeable metal hydrides may be competitive with conventional storage techniques. The basic theory of hydride behavior is presented and the engineering properties of LaNi5 are discussed to gain a clear understanding of the potential of metal hydrides for handling spacecraft hydrogen resources. Applications to Space Station and the safety of metal hydrides are presented and compared to conventional hydride storage. This comparison indicates that metal hydrides may be safer and require lower pressures, less volume, and less mass to store an equivalent mass of hydrogen.

  20. Space power systems--''Spacecraft 2000''

    Faymon, K.A.

    1985-01-01

    The National Space programs of the 21st century will require abundant and relatively low cost power and energy produced by high reliability-low mass systems. Advancement of current power system related technologies will enable the U.S. to realize increased scientific payload for government missions or increased revenue producing payload for commercial space endeavors. Autonomous, unattended operation will be a highly desirable characteristic of these advanced power systems. Those space power-energy related technologies, which will comprise the space craft of the late 1990's and the early 2000's, will evolve from today's state-of-the-art systems and those long term technology development programs presently in place. However, to foster accelerated development of the more critical technologies which have the potential for high-payoffs, additional programs will be proposed and put in place between now and the end of the century. Such a program is ''Spacecraft 2000'', which is described in this paper

  1. Optimal trajectories of aircraft and spacecraft

    Miele, A.

    1990-01-01

    Work done on algorithms for the numerical solutions of optimal control problems and their application to the computation of optimal flight trajectories of aircraft and spacecraft is summarized. General considerations on calculus of variations, optimal control, numerical algorithms, and applications of these algorithms to real-world problems are presented. The sequential gradient-restoration algorithm (SGRA) is examined for the numerical solution of optimal control problems of the Bolza type. Both the primal formulation and the dual formulation are discussed. Aircraft trajectories, in particular, the application of the dual sequential gradient-restoration algorithm (DSGRA) to the determination of optimal flight trajectories in the presence of windshear are described. Both take-off trajectories and abort landing trajectories are discussed. Take-off trajectories are optimized by minimizing the peak deviation of the absolute path inclination from a reference value. Abort landing trajectories are optimized by minimizing the peak drop of altitude from a reference value. Abort landing trajectories are optimized by minimizing the peak drop of altitude from a reference value. The survival capability of an aircraft in a severe windshear is discussed, and the optimal trajectories are found to be superior to both constant pitch trajectories and maximum angle of attack trajectories. Spacecraft trajectories, in particular, the application of the primal sequential gradient-restoration algorithm (PSGRA) to the determination of optimal flight trajectories for aeroassisted orbital transfer are examined. Both the coplanar case and the noncoplanar case are discussed within the frame of three problems: minimization of the total characteristic velocity; minimization of the time integral of the square of the path inclination; and minimization of the peak heating rate. The solution of the second problem is called nearly-grazing solution, and its merits are pointed out as a useful

  2. Radiation shielding calculations for the vista spacecraft

    Sahin, Suemer; Sahin, Haci Mehmet; Acir, Adem

    2005-01-01

    The VISTA spacecraft design concept has been proposed for manned or heavy cargo deep space missions beyond earth orbit with inertial fusion energy propulsion. Rocket propulsion is provided by fusion power deposited in the inertial confined fuel pellet debris and with the help of a magnetic nozzle. The calculations for the radiation shielding have been revised under the fact that the highest jet efficiency of the vehicle could be attained only if the propelling plasma would have a narrow temperature distribution. The shield mass could be reduced from 600 tons in the original design to 62 tons. Natural and enriched lithium were the principle shielding materials. The allowable nuclear heating in the superconducting magnet coils (up to 5 mW/cm 3 ) is taken as the crucial criterion for dimensioning the radiation shielding structure of the spacecraft. The space craft mass is 6000 tons. Total peak nuclear power density in the coils is calculated as ∼5.0 mW/cm 3 for a fusion power output of 17 500 MW. The peak neutron heating density is ∼2.0 mW/cm 3 , and the peak γ-ray heating density is ∼3.0 mW/cm 3 (on different points) using natural lithium in the shielding. However, the volume averaged heat generation in the coils is much lower, namely 0.21, 0.71 and 0.92 mW/cm 3 for the neutron, γ-ray and total nuclear heating, respectively. The coil heating will be slightly lower if highly enriched 6 Li (90%) is used instead of natural lithium. Peak values are then calculated as 2.05, 2.15 and 4.2 mW/cm 3 for the neutron, γ-ray and total nuclear heating, respectively. The corresponding volume averaged heat generation in the coils became 0.19, 0.58 and 0.77 mW/cm 3

  3. Multiple spacecraft observations of interplanetary shocks: four spacecraft determination of shock normals

    Russell, C.T.; Mellott, M.M.; Smith, E.J.; King, J.H.

    1983-01-01

    ISEE 1,2,3 IMP8, and Prognoz 7 observations of interplanetary shocks in 1978 and 1979 provide five instances where a single shock is observed by four spacecraft. These observations are used to determine best-fit normals for these five shocks. In addition to providing well-documented shocks for furture techniques. When the angle between upstream and downstream magnetic field is greater than 20, magnetic coplanarity can be an accurate single spacecraft method. However, no technique based solely on the magnetic measurements at one or multiple sites was universally accurate. Thus, we recommend using overdetermined shock normal solutions whenever possible, utilizing plasma measurements, separation vectors, and time delays together with magnetic constraints

  4. Multiple spacecraft observations of interplanetary shocks Four spacecraft determination of shock normals

    Russell, C. T.; Mellott, M. M.; Smith, E. J.; King, J. H.

    1983-01-01

    ISEE 1, 2, 3, IMP 8, and Prognoz 7 observations of interplanetary shocks in 1978 and 1979 provide five instances where a single shock is observed by four spacecraft. These observations are used to determine best-fit normals for these five shocks. In addition to providing well-documented shocks for future investigations these data allow the evaluation of the accuracy of several shock normal determination techniques. When the angle between upstream and downstream magnetic field is greater than 20 deg, magnetic coplanarity can be an accurate single spacecraft method. However, no technique based solely on the magnetic measurements at one or multiple sites was universally accurate. Thus, the use of overdetermined shock normal solutions, utilizing plasma measurements, separation vectors, and time delays together with magnetic constraints, is recommended whenever possible.

  5. Spacecraft formation control using analytical finite-duration approaches

    Ben Larbi, Mohamed Khalil; Stoll, Enrico

    2018-03-01

    This paper derives a control concept for formation flight (FF) applications assuming circular reference orbits. The paper focuses on a general impulsive control concept for FF which is then extended to the more realistic case of non-impulsive thrust maneuvers. The control concept uses a description of the FF in relative orbital elements (ROE) instead of the classical Cartesian description since the ROE provide a direct insight into key aspects of the relative motion and are particularly suitable for relative orbit control purposes and collision avoidance analysis. Although Gauss' variational equations have been first derived to offer a mathematical tool for processing orbit perturbations, they are suitable for several different applications. If the perturbation acceleration is due to a control thrust, Gauss' variational equations show the effect of such a control thrust on the Keplerian orbital elements. Integrating the Gauss' variational equations offers a direct relation between velocity increments in the local vertical local horizontal frame and the subsequent change of Keplerian orbital elements. For proximity operations, these equations can be generalized from describing the motion of single spacecraft to the description of the relative motion of two spacecraft. This will be shown for impulsive and finite-duration maneuvers. Based on that, an analytical tool to estimate the error induced through impulsive maneuver planning is presented. The resulting control schemes are simple and effective and thus also suitable for on-board implementation. Simulations show that the proposed concept improves the timing of the thrust maneuver executions and thus reduces the residual error of the formation control.

  6. Professional Socialisation of Valuers: Program Directors Perspective

    Page, Geoff

    2007-01-01

    An examination of the professional socialisation process is critical in changing the way graduates are trained and how they are supported post graduation. This article summarises key mechanisms to facilitate socialisation from recent socialisation studies undertaken in the fields of medicine, physical therapy nursing, occupational therapy, and…

  7. Critical Care Pharmacist Market Perceptions: Comparison of Critical Care Program Directors and Directors of Pharmacy.

    Hager, David R; Persaud, Rosemary A; Naseman, Ryan W; Choudhary, Kavish; Carter, Kristen E; Hansen, Amanda

    2017-05-01

    Background: While hospital beds continue to decline as patients previously treated as inpatients are stabilized in ambulatory settings, the number of critical care beds available in the United States continues to rise. Growth in pharmacy student graduation, postgraduate year 2 critical care (PGY2 CC) residency programs, and positions has also increased. There is a perception that the critical care trained pharmacist market is saturated, yet this has not been evaluated since the rise in pharmacy graduates and residency programs. Purpose: To describe the current perception of critical care residency program directors (CC RPDs) and directors of pharmacy (DOPs) on the critical care pharmacist job market and to evaluate critical care postresidency placement and anticipated changes in PGY2 CC programs. Methods: Two electronic surveys were distributed from October 2015 to November 2015 through Vizient/University HealthSystem Consortium, American Society of Health-System Pharmacists (ASHP), Society of Critical Care Medicine, and American College of Clinical Pharmacy listservs to target 2 groups of respondents: CC RPDs and DOPs. Questions were based on the ASHP Pharmacy Forecast and the Pharmacy Workforce Center's Aggregate Demand Index and were intended to identify perceptions of the critical care market of the 2 groups. Results: Of 116 CC RPDs, there were 66 respondents (56.9% response rate). Respondents have observed an increase in applicants; however, they do not anticipate increasing the number of positions in the next 5 years. The overall perception is that there is a balance in supply and demand in the critical care trained pharmacist market. A total of 82 DOPs responded to the survey. Turnover of critical care pharmacists within respondent organizations is expected to be low. Although a majority of DOPs plan to expand residency training positions, only 9% expect to increase positions in critical care PGY2 training. Overall, DOP respondents indicated a balance of

  8. Trajectory Control of Rendezvous with Maneuver Target Spacecraft

    Zhou, Zhinqiang

    2012-01-01

    In this paper, a nonlinear trajectory control algorithm of rendezvous with maneuvering target spacecraft is presented. The disturbance forces on the chaser and target spacecraft and the thrust forces on the chaser spacecraft are considered in the analysis. The control algorithm developed in this paper uses the relative distance and relative velocity between the target and chaser spacecraft as the inputs. A general formula of reference relative trajectory of the chaser spacecraft to the target spacecraft is developed and applied to four different proximity maneuvers, which are in-track circling, cross-track circling, in-track spiral rendezvous and cross-track spiral rendezvous. The closed-loop differential equations of the proximity relative motion with the control algorithm are derived. It is proven in the paper that the tracking errors between the commanded relative trajectory and the actual relative trajectory are bounded within a constant region determined by the control gains. The prediction of the tracking errors is obtained. Design examples are provided to show the implementation of the control algorithm. The simulation results show that the actual relative trajectory tracks the commanded relative trajectory tightly. The predicted tracking errors match those calculated in the simulation results. The control algorithm developed in this paper can also be applied to interception of maneuver target spacecraft and relative trajectory control of spacecraft formation flying.

  9. Rockets and spacecraft: Sine qua non of space science

    1980-01-01

    The evolution of the national launch vehicle stable is presented along with lists of launch vehicles used in NASA programs. A partial list of spacecraft used throughout the world is also given. Scientific spacecraft costs are presented along with an historial overview of project development and funding in NASA.

  10. Design feasibility via ascent optimality for next-generation spacecraft

    Miele, A.; Mancuso, S.

    This paper deals with the optimization of the ascent trajectories for single-stage-sub-orbit (SSSO), single-stage-to-orbit (SSTO), and two-stage-to-orbit (TSTO) rocket-powered spacecraft. The maximum payload weight problem is studied for different values of the engine specific impulse and spacecraft structural factor. The main conclusions are that: feasibility of SSSO spacecraft is guaranteed for all the parameter combinations considered; feasibility of SSTO spacecraft depends strongly on the parameter combination chosen; not only feasibility of TSTO spacecraft is guaranteed for all the parameter combinations considered, but the TSTO payload is several times the SSTO payload. Improvements in engine specific impulse and spacecraft structural factor are desirable and crucial for SSTO feasibility; indeed, aerodynamic improvements do not yield significant improvements in payload. For SSSO, SSTO, and TSTO spacecraft, simple engineering approximations are developed connecting the maximum payload weight to the engine specific impulse and spacecraft structural factor. With reference to the specific impulse/structural factor domain, these engineering approximations lead to the construction of zero-payload lines separating the feasibility region (positive payload) from the unfeasibility region (negative payload).

  11. Spacecraft Charging Modeling -- Nascap-2k 2014 Annual Report

    2014-09-19

    appears to work similarly in Internet Explorer, FireFox , and Opera, but fails in Safari and Chrome. Note that the SEE Spacecraft Charging Handbook is... Characteristics of Spacecraft Charging in Low Earth Orbit, J Geophys Res. 11 7, doi: 10.1029/20 11JA016875, 2012. 2 M. Cho, K. Saito, T. Hamanaga, Data

  12. Precise Relative Positioning of Formation Flying Spacecraft using GPS

    Kroes, R.

    2006-01-01

    Spacecraft formation flying is considered as a key technology for advanced space missions. Compared to large individual spacecraft, the distribution of sensor systems amongst multiple platforms offers improved flexibility, shorter times to mission, and the prospect of being more cost effective.

  13. Spacecraft attitude determination using the earth's magnetic field

    Simpson, David G.

    1989-01-01

    A method is presented by which the attitude of a low-Earth orbiting spacecraft may be determined using a vector magnetometer, a digital Sun sensor, and a mathematical model of the Earth's magnetic field. The method is currently being implemented for the Solar Maximum Mission spacecraft (as a backup for the failing star trackers) as a way to determine roll gyro drift.

  14. A Comparison of Learning Technologies for Teaching Spacecraft Software Development

    Straub, Jeremy

    2014-01-01

    The development of software for spacecraft represents a particular challenge and is, in many ways, a worst case scenario from a design perspective. Spacecraft software must be "bulletproof" and operate for extended periods of time without user intervention. If the software fails, it cannot be manually serviced. Software failure may…

  15. Research leadership: should clinical directors be distinguished researchers?

    Allison, Stephen; Goodall, Amanda H; Bastiampillai, Tarun

    2016-06-01

    Clinical directors established research-led healthcare by combining research, teaching and clinical excellence within the teaching hospitals. This research culture created high clinical standards, which benefited patients, the workforce and healthcare organisations. The current paper explores this research leadership role for clinical directors. It reviews studies arising from the theory of expert leadership, which focuses on the relationship between a leader's core knowledge and organisational performance. More specifically, we examine the expert leader's research track record, the associations with their organisation's performance, and the influence of research activity on clinical excellence. Distinguished researchers still lead the most prestigious teaching hospitals and the most trusted departments of psychiatry in the United States where the clinical directorate structure originated. It is also known that good scholars can improve research output when appointed to leadership positions. This suggests that the clinical director's research track record should be a consideration at a time when research is being embedded in Australia's local health networks. A clinical director's leadership may influence the research performance of their department and contribute to the quality of mental healthcare. © The Royal Australian and New Zealand College of Psychiatrists 2015.

  16. Looking good or doing better? Patterns of decoupling in the implementation of clinical directorates.

    Mascia, Daniele; Morandi, Federica; Cicchetti, Americo

    2014-01-01

    The interest toward hospital restructuring has risen significantly in recent years. In spite of its potential benefits, often organizational restructuring in health care produces unexpected consequences. Extant research suggests that institutional theory provides a powerful theoretical lens through which hospital restructuring can be described and explained. According to this perspective, the effectiveness of change is strongly related to the extent to which innovative arrangements, tools, or practices are adopted and implemented within hospitals. Whenever these new arrangements require a substantial modification of internal processes and practices, resistance to implementation emerges and organizational change is likely to become neutralized. This study analyzes how hospital organizations engage in decoupling by adopting but not implementing a new organizational model named clinical directorate. We collected primary data on the diffusion of the clinical directorate model, which was mandated by law in the Italian National Health Service to improve hospital services. We surveyed the adoption and implementation of the clinical directorate model by monitoring the presence of clinical governance tools (measures for the quality improvement of hospital services) within single directorates. In particular, we compared hospitals that adopted the model before (early adopters) or after (later adopters) the mandate was introduced. Hospitals were engaged in decoupling by adopting the new arrangement but not implementing internal practices and tools for quality improvement. The introduction of the law significantly affected the decoupling, with late-adopter hospitals being less likely to implement the adopted model. The present research shows that changes in quality improvement processes may vary in relation to policy makers' interventions aimed at boosting the adoption of new hospital arrangements. Hospital administrators need to be aware and identify the institutional changes

  17. Low cost spacecraft computers: Oxymoron or future trend?

    Manning, Robert M.

    1993-01-01

    Over the last few decades, application of current terrestrial computer technology in embedded spacecraft control systems has been expensive and wrought with many technical challenges. These challenges have centered on overcoming the extreme environmental constraints (protons, neutrons, gamma radiation, cosmic rays, temperature, vibration, etc.) that often preclude direct use of commercial off-the-shelf computer technology. Reliability, fault tolerance and power have also greatly constrained the selection of spacecraft control system computers. More recently, new constraints are being felt, cost and mass in particular, that have again narrowed the degrees of freedom spacecraft designers once enjoyed. This paper discusses these challenges, how they were previously overcome, how future trends in commercial computer technology will simplify (or hinder) selection of computer technology for spacecraft control applications, and what spacecraft electronic system designers can do now to circumvent them.

  18. Historical Mass, Power, Schedule, and Cost Growth for NASA Spacecraft

    Hayhurst, Marc R.; Bitten, Robert E.; Shinn, Stephen A.; Judnick, Daniel C.; Hallgrimson, Ingrid E.; Youngs, Megan A.

    2016-01-01

    Although spacecraft developers have been moving towards standardized product lines as the aerospace industry has matured, NASA's continual need to push the cutting edge of science to accomplish unique, challenging missions can still lead to spacecraft resource growth over time. This paper assesses historical mass, power, cost, and schedule growth for multiple NASA spacecraft from the last twenty years and compares to industry reserve guidelines to understand where the guidelines may fall short. Growth is assessed from project start to launch, from the time of the preliminary design review (PDR) to launch and from the time of the critical design review (CDR) to launch. Data is also assessed not just at the spacecraft bus level, but also at the subsystem level wherever possible, to help obtain further insight into possible drivers of growth. Potential recommendations to minimize spacecraft mass, power, cost, and schedule growth for future missions are also discussed.

  19. Iterative Repair Planning for Spacecraft Operations Using the Aspen System

    Rabideau, G.; Knight, R.; Chien, S.; Fukunaga, A.; Govindjee, A.

    2000-01-01

    This paper describes the Automated Scheduling and Planning Environment (ASPEN). ASPEN encodes complex spacecraft knowledge of operability constraints, flight rules, spacecraft hardware, science experiments and operations procedures to allow for automated generation of low level spacecraft sequences. Using a technique called iterative repair, ASPEN classifies constraint violations (i.e., conflicts) and attempts to repair each by performing a planning or scheduling operation. It must reason about which conflict to resolve first and what repair method to try for the given conflict. ASPEN is currently being utilized in the development of automated planner/scheduler systems for several spacecraft, including the UFO-1 naval communications satellite and the Citizen Explorer (CX1) satellite, as well as for planetary rover operations and antenna ground systems automation. This paper focuses on the algorithm and search strategies employed by ASPEN to resolve spacecraft operations constraints, as well as the data structures for representing these constraints.

  20. Spacecraft design project: Low Earth orbit communications satellite

    Moroney, Dave; Lashbrook, Dave; Mckibben, Barry; Gardener, Nigel; Rivers, Thane; Nottingham, Greg; Golden, Bill; Barfield, Bill; Bruening, Joe; Wood, Dave

    1991-01-01

    This is the final product of the spacecraft design project completed to fulfill the academic requirements of the Spacecraft Design and Integration 2 course (AE-4871) taught at the U.S. Naval Postgraduate School. The Spacecraft Design and Integration 2 course is intended to provide students detailed design experience in selection and design of both satellite system and subsystem components, and their location and integration into a final spacecraft configuration. The design team pursued a design to support a Low Earth Orbiting (LEO) communications system (GLOBALSTAR) currently under development by the Loral Cellular Systems Corporation. Each of the 14 team members was assigned both primary and secondary duties in program management or system design. Hardware selection, spacecraft component design, analysis, and integration were accomplished within the constraints imposed by the 11 week academic schedule and the available design facilities.

  1. Managing information risk a director's guide

    Mitchell, Stewart

    2009-01-01

    This pocket guide addresses the scope of risks involved in a modern IT system, and outlines strategies for working through the process of putting risk management at the heart of your corporate culture. Given that no two companies are the same, this pocket guide should not be taken as a step-by-step guide, but should provide decision makers with a solid overview of the factors they need to consider and a framework for implementing a regime that suits their needs.

  2. Economic analysis of open space box model utilization in spacecraft

    Mohammad, Atif F.; Straub, Jeremy

    2015-05-01

    It is a known fact that the amount of data about space that is stored is getting larger on an everyday basis. However, the utilization of Big Data and related tools to perform ETL (Extract, Transform and Load) applications will soon be pervasive in the space sciences. We have entered in a crucial time where using Big Data can be the difference (for terrestrial applications) between organizations underperforming and outperforming their peers. The same is true for NASA and other space agencies, as well as for individual missions and the highly-competitive process of mission data analysis and publication. In most industries, conventional opponents and new candidates alike will influence data-driven approaches to revolutionize and capture the value of Big Data archives. The Open Space Box Model is poised to take the proverbial "giant leap", as it provides autonomic data processing and communications for spacecraft. We can find economic value generated from such use of data processing in our earthly organizations in every sector, such as healthcare, retail. We also can easily find retailers, performing research on Big Data, by utilizing sensors driven embedded data in products within their stores and warehouses to determine how these products are actually used in the real world.

  3. Sean Michaletz Directors Post Doc Fellow Report

    Wilson, Cathy Jean [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-10-30

    Predicting climate change effects on plant function is a central challenge of global change biology and a primary mission of DOE. Although increasing temperatures and drought have been associated with reduced growth and increased mortality of plants, accurate prediction of such responses is limited by a lack of process-based theory linking climate and whole-plant physiology. This inability to predict forest mortality can cause significant biases in climate forecasts. One way forward is metabolic scaling theory (MST), which proposes that physiologic rates – from cells to the globe – are governed by the rates of resource distribution through vascular networks and the kinetics of resource utilization by metabolic reactions. MST has traditionally not considered rates of resource acquisition from organism-environment interactions, but it has an ideal mechanistic basis for doing so. As a first step towards integrating these processes, Sean has extended MST to characterize effects of temperature and precipitation on plant growth and ecosystem production. Sean’s post doc fellowship aimed to address a remaining shortcoming in that the new theory does not yet consider the physical processes of resource acquisition, and thus cannot mechanistically predict plant performance in a changing climate.

  4. Potential of Field Education as Signature Pedagogy: The Field Director Role

    Lyter, Sharon C.

    2012-01-01

    In light of the assertion that field education is the signature pedagogy of social work education, this Internet-based study explores field director demographics and questions the fulfillment of this potential, examining BSW and MSW field education through the lens of the field director position. Field directors (159) and deans/directors (150)…

  5. On the concept of survivability, with application to spacecraft and space-based networks

    Castet, Jean-Francois; Saleh, Joseph H.

    2012-01-01

    Survivability is an important attribute and requirement for military systems. Recently, survivability has become increasingly important for public infrastructure systems as well. In this work, we bring considerations of survivability to bear on space systems. We develop a conceptual framework and quantitative analyses based on stochastic Petri nets (SPN) to characterize and compare the survivability of different space architectures. The architectures here considered are a monolith spacecraft and a space-based network. To build the stochastic Petri net models for the degradations and failures of these two architectures, we conducted statistical analyses of historical multi-state failure data of spacecraft subsystems, and we assembled these subsystems, and their SPN models, in ways to create our monolith and networked systems. Preliminary results indicate, and quantify the extent to which, a space-based network is more survivable than the monolith spacecraft with respect to on-orbit anomalies and failures. For space systems, during the design and acquisition process, different architectures are benchmarked against several metrics; we argue that if survivability is not accounted for, then the evaluation process is likely to be biased in favor of the traditional dominant design, namely the monolith spacecraft. If however in a given context, survivability is a critical requirement for a customer, the survivability framework here proposed, and the stochastic modeling capability developed, can demonstrate the extent to which a networked space architecture may better satisfy this requirement than a monolith spacecraft. These results should be of interest to operators whose space assets require high levels of survivability, especially in the light of emerging threats.

  6. Spacecraft attitude and velocity control system

    Paluszek, Michael A. (Inventor); Piper, Jr., George E. (Inventor)

    1992-01-01

    A spacecraft attitude and/or velocity control system includes a controller which responds to at least attitude errors to produce command signals representing a force vector F and a torque vector T, each having three orthogonal components, which represent the forces and torques which are to be generated by the thrusters. The thrusters may include magnetic torquer or reaction wheels. Six difference equations are generated, three having the form ##EQU1## where a.sub.j is the maximum torque which the j.sup.th thruster can produce, b.sub.j is the maximum force which the j.sup.th thruster can produce, and .alpha..sub.j is a variable representing the throttling factor of the j.sup.th thruster, which may range from zero to unity. The six equations are summed to produce a single scalar equation relating variables .alpha..sub.j to a performance index Z: ##EQU2## Those values of .alpha. which maximize the value of Z are determined by a method for solving linear equations, such as a linear programming method. The Simplex method may be used. The values of .alpha..sub.j are applied to control the corresponding thrusters.

  7. Humidity Testing for Human Rated Spacecraft

    Johnson, Gary B.

    2009-01-01

    Determination that equipment can operate in and survive exposure to the humidity environments unique to human rated spacecraft presents widely varying challenges. Equipment may need to operate in habitable volumes where the atmosphere contains perspiration, exhalation, and residual moisture. Equipment located outside the pressurized volumes may be exposed to repetitive diurnal cycles that may result in moisture absorption and/or condensation. Equipment may be thermally affected by conduction to coldplate or structure, by forced or ambient air convection (hot/cold or wet/dry), or by radiation to space through windows or hatches. The equipment s on/off state also contributes to the equipment s susceptibility to humidity. Like-equipment is sometimes used in more than one location and under varying operational modes. Due to these challenges, developing a test scenario that bounds all physical, environmental and operational modes for both pressurized and unpressurized volumes requires an integrated assessment to determine the "worst-case combined conditions." Such an assessment was performed for the Constellation program, considering all of the aforementioned variables; and a test profile was developed based on approximately 300 variable combinations. The test profile has been vetted by several subject matter experts and partially validated by testing. Final testing to determine the efficacy of the test profile on actual space hardware is in the planning stages. When validation is completed, the test profile will be formally incorporated into NASA document CxP 30036, "Constellation Environmental Qualification and Acceptance Testing Requirements (CEQATR)."

  8. Kalman Filter for Spinning Spacecraft Attitude Estimation

    Markley, F. Landis; Sedlak, Joseph E.

    2008-01-01

    This paper presents a Kalman filter using a seven-component attitude state vector comprising the angular momentum components in an inertial reference frame, the angular momentum components in the body frame, and a rotation angle. The relatively slow variation of these parameters makes this parameterization advantageous for spinning spacecraft attitude estimation. The filter accounts for the constraint that the magnitude of the angular momentum vector is the same in the inertial and body frames by employing a reduced six-component error state. Four variants of the filter, defined by different choices for the reduced error state, are tested against a quaternion-based filter using simulated data for the THEMIS mission. Three of these variants choose three of the components of the error state to be the infinitesimal attitude error angles, facilitating the computation of measurement sensitivity matrices and causing the usual 3x3 attitude covariance matrix to be a submatrix of the 6x6 covariance of the error state. These variants differ in their choice for the other three components of the error state. The variant employing the infinitesimal attitude error angles and the angular momentum components in an inertial reference frame as the error state shows the best combination of robustness and efficiency in the simulations. Attitude estimation results using THEMIS flight data are also presented.

  9. Medical Significance of Microorganisms in Spacecraft Environment

    Pierson, Duane L.; Ott, C. Mark

    2007-01-01

    Microorganisms can spoil food supplies, contaminate drinking water, release noxious volatile compounds, initiate allergic responses, contaminate the environment, and cause infectious diseases. International acceptability limits have been established for bacterial and fungal contaminants in air and on surfaces, and environmental monitoring is conducted to ensure compliance. Allowable levels of microorganism in water and food have also been established. Environmental monitoring of the space shuttle, the Mir, and the ISS have allowed for some general conclusions. Generally, the bacteria found in air and on interior surfaces are largely of human origin such as Staphylococcus spp., Micrococcus spp. Common environmental genera such as Bacillus spp. are the most commonly isolated bacteria from all spacecraft. Yeast species associated with humans such as Candida spp. are commonly found. Aspergillus spp., Penicillium spp., and Cladosporium spp. are the most commonly isolated filamentous fungi. Microbial levels in the environment differ significantly depending upon humidity levels, condensate accumulation, and availability of carbon sources. However, human "normal flora" of bacteria and fungi can result in serious, life-threatening diseases if human immunity is compromised. Disease incidence is expected to increase as mission duration increases.

  10. Programs To Optimize Spacecraft And Aircraft Trajectories

    Brauer, G. L.; Petersen, F. M.; Cornick, D.E.; Stevenson, R.; Olson, D. W.

    1994-01-01

    POST/6D POST is set of two computer programs providing ability to target and optimize trajectories of powered or unpowered spacecraft or aircraft operating at or near rotating planet. POST treats point-mass, three-degree-of-freedom case. 6D POST treats more-general rigid-body, six-degree-of-freedom (with point masses) case. Used to solve variety of performance, guidance, and flight-control problems for atmospheric and orbital vehicles. Applications include computation of performance or capability of vehicle in ascent, or orbit, and during entry into atmosphere, simulation and analysis of guidance and flight-control systems, dispersion-type analyses and analyses of loads, general-purpose six-degree-of-freedom simulation of controlled and uncontrolled vehicles, and validation of performance in six degrees of freedom. Written in FORTRAN 77 and C language. Two machine versions available: one for SUN-series computers running SunOS(TM) (LAR-14871) and one for Silicon Graphics IRIS computers running IRIX(TM) operating system (LAR-14869).

  11. Spaceborne intensity interferometry via spacecraft formation flight

    Ribak, Erez N.; Gurfil, Pini; Moreno, Coral

    2012-07-01

    Interferometry in space has marked advantages: long integration times and observation in spectral bands where the atmosphere is opaque. When installed on separate spacecraft, it also has extended and flexible baselines for better filling of the uv plane. Intensity interferometry has an additional advantage, being insensitive to telescope and path errors, but is unfortunately much less light-sensitive. In planning towards such a mission, we are experimenting with some fundamental research issues. Towards this end, we constructed a system of three vehicles floating on an air table in formation flight, with an autonomous orbit control. Each such device holds its own light collector, detector, and transmitter, to broadcast its intensity signal towards a central receiving station. At this station we implement parallel radio receivers, analogue to digital converters, and a digital three-way correlator. Current technology limits us to ~1GHz transmission frequency, which corresponds to a comfortable 0.3m accuracy in light-bucket shape and in its relative position. Naïve calculations place our limiting magnitude at ~7 in the blue and ultraviolet, where amplitude interferometers are limited. The correlation signal rides on top of this huge signal with its own Poisson noise, requiring a very large dynamic range, which needs to be transmitted in full. We are looking at open questions such as deployable optical collectors and radio antennae of similar size of a few meters, and how they might influence our data transmission and thus set our flux limit.

  12. Spacecraft with gradual acceleration of solar panels

    Merhav, Tamir R. (Inventor); Festa, Michael T. (Inventor); Stetson, Jr., John B. (Inventor)

    1996-01-01

    A spacecraft (8) includes a movable appendage such as solar panels (12) operated by a stepping motor (28) driven by pulses (311). In order to reduce vibration andor attitude error, the drive pulses are generated by a clock down-counter (312) with variable count ratio. Predetermined desired clock ratios are stored in selectable memories (314a-d), and the selected ratio (R) is coupled to a comparator (330) together with the current ratio (C). An up-down counter (340) establishes the current count-down ratio by counting toward the desired ratio under the control of the comparator; thus, a step change of solar panel speed never occurs. When a direction change is commanded, a flag signal generator (350) disables the selectable memories, and enables a further store (360), which generates a count ratio representing a very slow solar panel rotational rate, so that the rotational rate always slows to a low value before direction is changed. The principles of the invention are applicable to any movable appendage.

  13. Female directors and real activities manipulation: Evidence from China

    Jin-hui Luo

    2017-06-01

    Full Text Available Unlike previous studies that focus on accrual-based earnings management, this study analyzes real activities manipulation and investigates whether female directors on boards of directors (BoDs affect managers’ real activities manipulation. Using a large sample of 11,831 firm-year observations from Chinese listed companies from the 2000 to 2011 period, we find that higher female participation on BoDs is associated with lower levels of real activities manipulation, and that this negative relationship is stronger when female directors have higher ownership. These results hold for a battery of robustness checks. Overall, our findings indicate that board gender diversity may serve as a substitute mechanism for corporate governance to curb real activities manipulation and thus provide interested stakeholders with higher quality earnings reports.

  14. Why so few Women on Boards of Directors?

    Smith, Nina; Parrotta, Pierpaolo

    2015-01-01

    This paper analyzes the determinants of women’s representation on boards of directors based on a panel of all privately owned or listed Danish firms with at least 50 employees observed during the period 1998–2010. We focus on the directors who are not elected by the employees and test three...... nonemployee-elected female board members. We also find clear evidence of a tokenism behavior in Danish companies. The likelihood of enlarging the share of non-employee-elected female board members is significantly smaller if one, two, or more women have sat on the board of directors. Finally, the pipeline...... suggests that an important way to increase the female proportion of non-employee-elected board members is that more women reach top executive positions....

  15. Perceptions of relative attractiveness of nature-based tourism assets: A comparison between CVB directors and visitors

    Jinyang Deng; David Dyre; Jing Wang

    2012-01-01

    This study uses the Analytic Hierarchy Process (AHP) to examine the similarities and differences between directors of Convention and Visitors Bureaus (CVB) and the general travelling public in their perceptions of the attractiveness of nature-based tourism resources in the state of West Virginia.

  16. 77 FR 34046 - Advisory Committee to the Director (ACD), Centers for Disease Control and Prevention (CDC)-Ethics...

    2012-06-08

    ... Committee to the Director (ACD), Centers for Disease Control and Prevention (CDC)--Ethics Subcommittee (ES... ACD, CDC, regarding a broad range of public health ethics questions and issues arising from programs... ethics standards to the accreditation process for public health departments; ethical considerations...

  17. Vibration and Acoustic Testing for Mars Micromission Spacecraft

    Kern, Dennis L.; Scharton, Terry D.

    1999-01-01

    The objective of the Mars Micromission program being managed by the Jet Propulsion Laboratory (JPL) for NASA is to develop a common spacecraft that can carry telecommunications equipment and a variety of science payloads for exploration of Mars. The spacecraft will be capable of carrying robot landers and rovers, cameras, probes, balloons, gliders or aircraft, and telecommunications equipment to Mars at much lower cost than recent NASA Mars missions. The lightweight spacecraft (about 220 Kg mass) will be launched in a cooperative venture with CNES as a TWIN auxiliary payload on the Ariane 5 launch vehicle. Two or more Mars Micromission launches are planned for each Mars launch opportunity, which occur every 26 months. The Mars launch window for the first mission is November 1, 2002 through April 2003, which is planned to be a Mars airplane technology demonstration mission to coincide with the 100 year anniversary of the Kittyhawk flight. Several subsequent launches will create a telecommunications network orbiting Mars, which will provide for continuous communication with lenders and rovers on the Martian surface. Dedicated science payload flights to Mars are slated to start in 2005. This new cheaper and faster approach to Mars exploration calls for innovative approaches to the qualification of the Mars Micromission spacecraft for the Ariane 5 launch vibration and acoustic environments. JPL has in recent years implemented new approaches to spacecraft testing that may be effectively applied to the Mars Micromission. These include 1) force limited vibration testing, 2) combined loads, vibration and modal testing, and 3) direct acoustic testing. JPL has performed nearly 200 force limited vibration tests in the past 9 years; several of the tests were on spacecraft and large instruments, including the Cassini and Deep Space One spacecraft. Force limiting, which measures and limits the spacecraft base reaction force using triaxial force gages sandwiched between the

  18. Materials and structures technology insertion into spacecraft systems: Successes and challenges

    Rawal, Suraj

    2018-05-01

    Over the last 30 years, significant advancements have led to the use of multifunctional materials and structures technologies in spacecraft systems. This includes the integration of adaptive structures, advanced composites, nanotechnology, and additive manufacturing technologies. Development of multifunctional structures has been directly influenced by the implementation of processes and tools for adaptive structures pioneered by Prof. Paolo Santini. Multifunctional materials and structures incorporating non-structural engineering functions such as thermal, electrical, radiation shielding, power, and sensors have been investigated. The result has been an integrated structure that offers reduced mass, packaging volume, and ease of integration for spacecraft systems. Current technology development efforts are being conducted to develop innovative multifunctional materials and structures designs incorporating advanced composites, nanotechnology, and additive manufacturing. However, these efforts offer significant challenges in the qualification and acceptance into spacecraft systems. This paper presents a brief overview of the technology development and successful insertion of advanced material technologies into spacecraft structures. Finally, opportunities and challenges to develop and mature next generation advanced materials and structures are presented.

  19. Thermal shock induced dynamics of a spacecraft with a flexible deploying boom

    Shen, Zhenxing; Li, Huijian; Liu, Xiaoning; Hu, Gengkai

    2017-12-01

    The dynamics in the process of deployment of a flexible extendible boom as a deployable structure on the spacecraft is studied. For determining the thermally induced vibrations of the boom subjected to an incident solar heat flux, an axially moving thermal-dynamic beam element based on the absolute nodal coordinate formulation which is able to precisely describe the large displacement, rotation and deformation of flexible body is presented. For the elastic forces formulation of variable-length beam element, the enhanced continuum mechanics approach is adopted, which can eliminate the Poisson locking effect, and take into account the tension-bending-torsion coupling deformations. The main body of the spacecraft, modeled as a rigid body, is described using the natural coordinates method. In the derived nonlinear thermal-dynamic equations of rigid-flexible multibody system, the mass matrix is time-variant, and a pseudo damping matrix which is without actual energy dissipation, and a heat conduction matrix which is relative to the moving speed and the number of beam element are arisen. Numerical results give the dynamic and thermal responses of the nonrotating and spinning spacecraft, respectively, and show that thermal shock has a significant influence on the dynamics of spacecraft.

  20. The SPQR experiment: detecting damage to orbiting spacecraft with ground-based telescopes

    Paolozzi, Antonio; Porfilio, Manfredi; Currie, Douglas G.; Dantowitz, Ronald F.

    2007-09-01

    The objective of the Specular Point-like Quick Reference (SPQR) experiment was to evaluate the possibility of improving the resolution of ground-based telescopic imaging of manned spacecraft in orbit. The concept was to reduce image distortions due to atmospheric turbulence by evaluating the Point Spread Function (PSF) of a point-like light reference and processing the spacecraft image accordingly. The target spacecraft was the International Space Station (ISS) and the point-like reference was provided by a laser beam emitted by the ground station and reflected back to the telescope by a Cube Corner Reflector (CCR) mounted on an ISS window. The ultimate objective of the experiment was to demonstrate that it is possible to image spacecraft in Low Earth Orbit (LEO) with a resolution of 20 cm, which would have probably been sufficient to detect the damage which caused the Columbia disaster. The experiment was successfully performed from March to May 2005. The paper provides an overview of the SPQR experiment.

  1. Burnout and Resiliency Among Family Medicine Program Directors.

    Porter, Maribeth; Hagan, Helen; Klassen, Rosemary; Yang, Yang; Seehusen, Dean A; Carek, Peter J

    2018-02-01

    Nearly one-half (46%) of physicians report at least one symptom of burnout. Family medicine residency program directors may have similar and potentially unique levels of burnout as well as resiliency. The primary aims of this study were to examine burnout and resiliency among family medicine residency directors and characterize associated factors. The questions used were part of a larger omnibus survey conducted by the Council of Academic Family Medicine (CAFM) Educational Research Alliance (CERA) in 2016. Program and director-specific characteristics were obtained. Symptoms of burnout were assessed using two single-item measures adapted from the full Maslach Burnout Inventory, and level of resiliency was assessed using the Brief Resilience Scale. The overall response rate for the survey was 53.7% (245/465). Symptoms of high emotional exhaustion or high depersonalization were reported in 27.3% and 15.8% of program directors, respectively. More than two-thirds of program directors indicated that they associated themselves with characteristics of resiliency. Emotional exhaustion and depersonalization were significantly correlated with never having personal time, an unhealthy work-life balance, and the inability to stop thinking about work. The presence of financial stress was significantly correlated with higher levels of emotional exhaustion and depersonalization. In contrast, the level of resiliency reported was directly correlated with having a moderate to great amount of personal time, healthy work-life balance, and ability to stop thinking about work, and negatively correlated with the presence of financial stress. Levels of emotional exhaustion, depersonalization, and resiliency are significantly related to personal characteristics of program directors rather than characteristics of their program.

  2. IAEA Director General welcomes landmark convention to combat nuclear terrorism

    2005-01-01

    Full text: IAEA Director General Mohamed ElBaradei welcomed the adoption of an International convention against nuclear terrorism. 'This is a landmark achievement which will bolster global efforts to combat nuclear terrorism,' Dr. ElBaradei said. 'It will be a key part of international efforts to prevent terrorists from gaining access to nuclear weapons'. The United Nations General Assembly adopted the convention, The International Convention for the Suppression of Acts of Nuclear Terrorism, on 13 April 2005. The Convention strengthens the global legal framework to counter terrorist threats. Based on a proposal by the Russian Federation in 1998, the Convention focuses on criminal offences related to nuclear terrorism and covers a broad range of possible targets, including nuclear reactors as well as nuclear material and radioactive substances. Under its provisions, alleged offenders - for example any individual or group that unlawfully and intentionally possesses or uses radioactive material with the intent to cause harm - must be either extradited or prosecuted. States are also encouraged to cooperate with each other in connection with criminal investigations and extradition proceedings. The Convention further requires that any seized nuclear or radiological material be held in accordance with IAEA safeguards, and handled in keeping with the IAEA's health, safety and physical protection standards. Dr. ElBaradei also recalled that the Agency is in the process of amending the Convention on the Physical Protection of Nuclear Material, in order to broaden its scope, and in so doing, strengthen the current legal framework for securing nuclear material against illicit uses. A conference will be held from 4 to 8 July in Vienna to consider and adopt the amendments. The Convention opens for signature in September this year. Dr ElBaradei urged all States to 'sign and ratify the Convention without delay so nuclear terrorism will have no chance'. (IAEA)

  3. Fabiola Gianotti signs her contract as CERN's new Director- General

    Antonella Del Rosso

    2014-01-01

    Today, 12 December 2014, Fabiola Gianotti signed her five-year contract as the new CERN Director-General. Her mandate will begin on 1 January 2016.   Fabiola Gianotti (left) and President of CERN Council Agnieszka Zalewska (right) after the signature of the contract.   The Italian physicist, Fabiola Gianotti was appointed as the Organization’s next Director-General at the 173rd Closed Session of the CERN Council on 4 November. The appointment was formalised this week at the December session of Council. More news from this week Council meetings can be found here.

  4. 2D director calculation for liquid crystal optical phased array

    Xu, L; Zhang, J; Wu, L Y

    2005-01-01

    A practical numerical model for a liquid crystal cell is set up based on the geometrical structure of liquid crystal optical phased arrays. Model parameters include width and space of electrodes, thickness of liquid crystal layer, alignment layers and glass substrates, pre-tilted angles, dielectric constants, elastic constants and so on. According to electrostatic field theory and Frank-Oseen elastic continuum theory, 2D electric potential distribution and 2D director distribution are calculated by means of the finite difference method on non-uniform grids. The influence of cell sizes on director distribution is analyzed. The fringe field effect between electrodes is also discussed

  5. Mergers and acquisitions: director and consultant liability exposure.

    Waxman, J M

    1995-02-01

    Corporate directors and their consultants must make decisions in an uncertain and changing health care environment. The losses each may face as a result of an incomplete analysis of the true value of the entities involved in mergers or acquisitions may extend beyond the failure of the transaction to the creation of personal liability as well. Accordingly, objective, careful, detailed, and fair decision-making based upon adequate information is more critical than ever for directors if they are to be able to take advantage of the business judgment rule, and also for consultants to avoid their own liability when transactions fail to deliver the values they have estimated.

  6. Four-spacecraft determination of magnetopause orientation, motion and thickness: comparison with results from single-spacecraft methods

    S. E. Haaland

    2004-04-01

    Full Text Available In this paper, we use Cluster data from one magnetopause event on 5 July 2001 to compare predictions from various methods for determination of the velocity, orientation, and thickness of the magnetopause current layer. We employ established as well as new multi-spacecraft techniques, in which time differences between the crossings by the four spacecraft, along with the duration of each crossing, are used to calculate magnetopause speed, normal vector, and width. The timing is based on data from either the Cluster Magnetic Field Experiment (FGM or the Electric Field Experiment (EFW instruments. The multi-spacecraft results are compared with those derived from various single-spacecraft techniques, including minimum-variance analysis of the magnetic field and deHoffmann-Teller, as well as Minimum-Faraday-Residue analysis of plasma velocities and magnetic fields measured during the crossings. In order to improve the overall consistency between multi- and single-spacecraft results, we have also explored the use of hybrid techniques, in which timing information from the four spacecraft is combined with certain limited results from single-spacecraft methods, the remaining results being left for consistency checks. The results show good agreement between magnetopause orientations derived from appropriately chosen single-spacecraft techniques and those obtained from multi-spacecraft timing. The agreement between magnetopause speeds derived from single- and multi-spacecraft methods is quantitatively somewhat less good but it is evident that the speed can change substantially from one crossing to the next within an event. The magnetopause thickness varied substantially from one crossing to the next, within an event. It ranged from 5 to 10 ion gyroradii. The density profile was sharper than the magnetic profile: most of the density change occured in the earthward half of the magnetopause.

    Key words. Magnetospheric physics (magnetopause, cusp and

  7. Attributes of Candidates Passing the ABS Certifying Examination on the First Attempt-Program Directors׳ Perspective.

    Sheikh, Mohd Raashid; Hulme, Michael

    2016-01-01

    The American Board of Surgery Certifying Examination (CE) is a pivotal event in a surgeon's career development, as it is the last challenge before achieving Board certification. First-time pass rate on the CE is one of the key metrics of surgery residency programs. The overall pass rate on the CE has declined significantly in recent years. The goal of this study was the identification of attributes of general surgery residents that are associated with passing the CE at the first attempt. The modified Delphi process was used to survey general surgery program directors. The study was conducted in 2 rounds in the interest of time available for surgical education research fellowship project. All 259 program directors were contacted in each round of surveys. In all, 49 (19%) responded to the first round and 54 (21%) responded to the second round of survey. The characteristics of a successful resident on CE include confidence, self-motivation, sound knowledge base, strong performance on the Board's training examination (American Board of Surgery In-Training Examination), and mock orals, and good communication skills. Postgraduate years 4 and 5 are the most likely resident levels at which failure could be predicted. Copyright © 2015 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  8. Delegation of powers to the director of the kindergarten the other leaders of the school, depending on the size of the school and the number of remote sites

    Benediktová, Karla

    2013-01-01

    The final bachelor thesis deals with the process how to delegate the nursery school director's power and responsibility to other senior executives. The theoretical part of the thesis makes use of the findings gained from the management literature, depicting the topic of delegating in a broader context. The subject is also applied to the education system, particularly nursery school directors. The analysis of the quantitative research, using questionnaire survey designed for nursery school dir...

  9. Time Frequency Analysis of Spacecraft Propellant Tank Spinning Slosh

    Green, Steven T.; Burkey, Russell C.; Sudermann, James

    2010-01-01

    Many spacecraft are designed to spin about an axis along the flight path as a means of stabilizing the attitude of the spacecraft via gyroscopic stiffness. Because of the assembly requirements of the spacecraft and the launch vehicle, these spacecraft often spin about an axis corresponding to a minor moment of inertia. In such a case, any perturbation of the spin axis will cause sloshing motions in the liquid propellant tanks that will eventually dissipate enough kinetic energy to cause the spin axis nutation (wobble) to grow further. This spinning slosh and resultant nutation growth is a primary design problem of spinning spacecraft and one that is not easily solved by analysis or simulation only. Testing remains the surest way to address spacecraft nutation growth. This paper describes a test method and data analysis technique that reveal the resonant frequency and damping behavior of liquid motions in a spinning tank. Slosh resonant frequency and damping characteristics are necessary inputs to any accurate numerical dynamic simulation of the spacecraft.

  10. Experiments study on attitude coupling control method for flexible spacecraft

    Wang, Jie; Li, Dongxu

    2018-06-01

    High pointing accuracy and stabilization are significant for spacecrafts to carry out Earth observing, laser communication and space exploration missions. However, when a spacecraft undergoes large angle maneuver, the excited elastic oscillation of flexible appendages, for instance, solar wing and onboard antenna, would downgrade the performance of the spacecraft platform. This paper proposes a coupling control method, which synthesizes the adaptive sliding mode controller and the positive position feedback (PPF) controller, to control the attitude and suppress the elastic vibration simultaneously. Because of its prominent performance for attitude tracking and stabilization, the proposed method is capable of slewing the flexible spacecraft with a large angle. Also, the method is robust to parametric uncertainties of the spacecraft model. Numerical simulations are carried out with a hub-plate system which undergoes a single-axis attitude maneuver. An attitude control testbed for the flexible spacecraft is established and experiments are conducted to validate the coupling control method. Both numerical and experimental results demonstrate that the method discussed above can effectively decrease the stabilization time and improve the attitude accuracy of the flexible spacecraft.

  11. Nursing home director of nursing leadership style and director of nursing-sensitive survey deficiencies.

    McKinney, Selina H; Corazzini, Kirsten; Anderson, Ruth A; Sloane, Richard; Castle, Nicholas G

    2016-01-01

    Nursing homes are becoming increasingly complex clinical environments because of rising resident acuity and expansion of postacute services within a context of historically poor quality performance. Discrete quality markers have been linked to director of nursing (DON) leadership behaviors. However, the impact of DON leadership across all measured areas of DON jurisdiction has not been tested using comprehensive domains of quality deficiencies. The aim of this study was to examine the effects of DON leadership style including behaviors that facilitate the exchange of information between diverse people on care quality domains through the lens of complexity science. Three thousand six hundred nine DONs completed leadership and intent-to-quit surveys. Quality markers that were deemed DON sensitive included all facility survey deficiencies in the domains of resident behaviors/facility practices, quality of life, nursing services, and quality of care. Logistic regression procedures estimated associations between variables. The odds of deficiencies for all DON sensitive survey domains were lower in facilities where DONs practiced complexity leadership including more staff input and shared decisional authority. DON quit intentions were aligned with higher odds of facility deficiencies across all domains. Results supported the hypotheses that DONs using complexity leadership approaches by interacting more freely with staff, discussing resident issues, and sharing decision making produced better care outcomes from every DON sensitive metric assessed by Centers for Medicare and Medicaid Services. The mechanism linking poor quality with high DON quit intentions is an area for future research. Encouraging DON use of complexity leadership approaches has the potential to improve a broad swath of quality outcomes.

  12. Intelligent Data Visualization for Cross-Checking Spacecraft System Diagnosis

    Ong, James C.; Remolina, Emilio; Breeden, David; Stroozas, Brett A.; Mohammed, John L.

    2012-01-01

    Any reasoning system is fallible, so crew members and flight controllers must be able to cross-check automated diagnoses of spacecraft or habitat problems by considering alternate diagnoses and analyzing related evidence. Cross-checking improves diagnostic accuracy because people can apply information processing heuristics, pattern recognition techniques, and reasoning methods that the automated diagnostic system may not possess. Over time, cross-checking also enables crew members to become comfortable with how the diagnostic reasoning system performs, so the system can earn the crew s trust. We developed intelligent data visualization software that helps users cross-check automated diagnoses of system faults more effectively. The user interface displays scrollable arrays of timelines and time-series graphs, which are tightly integrated with an interactive, color-coded system schematic to show important spatial-temporal data patterns. Signal processing and rule-based diagnostic reasoning automatically identify alternate hypotheses and data patterns that support or rebut the original and alternate diagnoses. A color-coded matrix display summarizes the supporting or rebutting evidence for each diagnosis, and a drill-down capability enables crew members to quickly view graphs and timelines of the underlying data. This system demonstrates that modest amounts of diagnostic reasoning, combined with interactive, information-dense data visualizations, can accelerate system diagnosis and cross-checking.

  13. Studies on black anodic coatings for spacecraft thermal control applications

    Uma Rani, R.; Subba Rao, Y.; Sharma, A.K. [ISRO Satellite Centre, Bangalore (India). Thermal Systems Group

    2011-10-15

    An inorganic black colouring process using nickel sulphate and sodium sulphide was investigated on anodized aluminium alloy 6061 to provide a flat absorber black coating for spacecraft thermal control applications. Influence of colouring process parameters (concentration, pH) on the physico-optical properties of black anodic film was investigated. The nature of black anodic film was evaluated by the measurement of film thickness, micro hardness and scanning electron microscopy (SEM). Energy dispersive X-ray spectroscopy studies confirmed the presence of nickel and sulphur in the black anodic coating. Electrochemical impedance spectroscopy (EIS) was used to evaluate the corrosion resistance of the coating. The environmental tests, namely, humidity, corrosion resistance, thermal cycling and thermo vacuum performance tests were used to evaluate the space worthiness of the coating. Optical properties of the film were measured before and after each environmental test to ascertain its stability in harsh space environment. The black anodic films provide higher thermal emittance ({proportional_to} 0.90) and solar absorptance ({proportional_to} 0.96) and their high stability during the environmental tests indicated their suitability for space and allied applications. (orig.)

  14. Aerogel Projects Ongoing in MSFC's Engineering Directorate

    Shular, David A.; Smithers, Gweneth A.; Plawsky, Joel L.; Whitaker, Ann F. (Technical Monitor)

    2000-01-01

    When we speak of an aerogel material, we are referring more to process and structure am to a specific substance. Aerogel, considered the lightest solid material, has been made from silica for seventy years. Resorcinol-formaldehyde, organic aerogels have been developed more recently. However, aerogel can be made from almost any type of substance, even lead. Because an aerogel is mostly air (about 99 %), the solid substance used will affect the weight very little. The term "aerogel" connotes the sol-gel process used to manufacture the material. The aerogel begins as a liquid "sol," becomes a solid "alcogel," and is then dried to become an "aerogel." The final product has a unique structure, useful for exploitation. It is an "open pore" system with nano-sized particles and pores, has very high surface area, and is highly interconnected. Besides low weight, aerogels have ultimate (lowest) values in other properties: thermal conductivity, refractive index, sound speed, and dielectric constant. Aerogels were first prepared in 1931 by Steven Kistler, who used a supercritical drying step to replace the liquid in a gel with air, preserving the structure (1). Kistler's procedure involved a water-to-alcohol exchange step; in the 1970's, this step was eliminated when a French investigator introduced the use of tetramethylorthosilicate. Still, alcohol drying involved dangerously high temperatures and pressures. In the 1980's, the Microstructured Materials Group at Berkeley Laboratory found that the alcohol in the gel could be replaced with liquid carbon dioxide before supercritical drying, which greatly improved safety (2). 'Me most recent major contribution has been that of Deshpande, Smith and Brinker in New Mexico, who are working to eliminate the supercritical drying step (3). When aerogels were first being developed, they were evaporatively dried. However, the wet gel, when dried, underwent severe shrinkage and cracking; this product was termed "xerogel." When the

  15. Air dehumidification by membrane with cold water for manned spacecraft environmental control

    Shang Yonghong

    2017-01-01

    Full Text Available The traditional condensation dehumidification method requires additional gas-liquid separation and water recovery process in the manned spacecraft humidity control system, which would increase weight and complexity of systems. A new membrane dehumidification with cold water is proposed, which uses water vapor partial pressure difference to promote water vapor transmembrane mass transfer for dehumidification. The permeability of the membrane was measured and the experimental results agree well with the theoretical calculations. Based on the simulation of dehumidification process of cold water-membrane, the influence of module structure and working condition on dehumidification performance was analyzed, which provided reference for the design of membrane module construct. It can be seen from the simulation and experiments that the cold water-membrane dehumidification can effectively reduce the thermal load of the manned spacecraft.

  16. Research on intelligent power distribution system for spacecraft

    Xia, Xiaodong; Wu, Jianju

    2017-10-01

    The power distribution system (PDS) mainly realizes the power distribution and management of the electrical load of the whole spacecraft, which is directly related to the success or failure of the mission, and hence is an important part of the spacecraft. In order to improve the reliability and intelligent degree of the PDS, and considering the function and composition of spacecraft power distribution system, this paper systematically expounds the design principle and method of the intelligent power distribution system based on SSPC, and provides the analysis and verification of the test data additionally.

  17. Preliminary thermal design of the COLD-SAT spacecraft

    Arif, Hugh

    1991-01-01

    The COLD-SAT free-flying spacecraft was to perform experiments with LH2 in the cryogenic fluid management technologies of storage, supply and transfer in reduced gravity. The Phase A preliminary design of the Thermal Control Subsystem (TCS) for the spacecraft exterior and interior surfaces and components of the bus subsystems is described. The TCS was composed of passive elements which were augmented with heaters. Trade studies to minimize the parasitic heat leakage into the cryogen storage tanks are described. Selection procedure for the thermally optimum on-orbit spacecraft attitude was defined. TRASYS-2 and SINDA'85 verification analysis was performed on the design and the results are presented.

  18. Ad hoc laser networks component technology for modular spacecraft

    Huang, Xiujun; Shi, Dele; Shen, Jingshi

    2017-10-01

    Distributed reconfigurable satellite is a new kind of spacecraft system, which is based on a flexible platform of modularization and standardization. Based on the module data flow analysis of the spacecraft, this paper proposes a network component of ad hoc Laser networks architecture. Low speed control network with high speed load network of Microwave-Laser communication mode, no mesh network mode, to improve the flexibility of the network. Ad hoc Laser networks component technology was developed, and carried out the related performance testing and experiment. The results showed that ad hoc Laser networks components can meet the demand of future networking between the module of spacecraft.

  19. Fifty-one years of Los Alamos Spacecraft

    Fenimore, Edward E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-09-04

    From 1963 to 2014, the Los Alamos National Laboratory was involved in at least 233 spacecraft. There are probably only one or two institutions in the world that have been involved in so many spacecraft. Los Alamos space exploration started with the Vela satellites for nuclear test detection, but soon expanded to ionospheric research (mostly barium releases), radioisotope thermoelectric generators, solar physics, solar wind, magnetospheres, astrophysics, national security, planetary physics, earth resources, radio propagation in the ionosphere, and cubesats. Here, we present a list of the spacecraft, their purpose, and their launch dates for use during RocketFest

  20. Iodine Plasma (Electric Propulsion) Interaction with Spacecraft Materials

    2016-12-28

    Teflon (AGT5, Ag-FEP) Thermal control surface (radiator) Spacecraft Exposure Soda-lime glass (74% SiO2 , 13% Na2O, 8% CaO, 4% MgO, 1% other oxide... Glass Solar panel cover Spacecraft Exposure Buna-N (acrylonitrile butadiene rubber) Seals Iodine Feed System Carbon fiber composite (epoxy resin...Fe Propellant isolator Spacecraft Exposure Lanthanum Hexaboride, LaB6 Cathode emitter Inside Cathode Yes MACOR (46% SiO2 , 17% MgO, 16% Al2O3, 10