WorldWideScience

Sample records for small spacecraft systems

  1. System Critical Design Audit (CDA). Books 1, 2 and 3; [Small Satellite Technology Initiative (SSTI Lewis Spacecraft Program)

    Science.gov (United States)

    1995-01-01

    Small Satellite Technology Initiative (SSTI) Lewis Spacecraft Program is evaluated. Spacecraft integration, test, launch, and spacecraft bus are discussed. Payloads and technology demonstrations are presented. Mission data management system and ground segment are also addressed.

  2. Small Spacecraft for Planetary Science

    Science.gov (United States)

    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.

  3. Small Spacecraft Integrated Power System with Active Thermal Control

    Data.gov (United States)

    National Aeronautics and Space Administration — This project will develop an integrated power generation and energy storage system with an active thermal management system. Carbon fiber solar panels will contain...

  4. Development of solid-gas equilibrium propulsion system for small spacecraft

    Science.gov (United States)

    Chujo, Toshihiro; Mori, Osamu; Kubo, Yuki

    2017-11-01

    A phase equilibrium propulsion system is a kind of cold-gas jet in which the phase equilibrium state of the fuel is maintained in a tank and its vapor is ejected when a valve is opened. One such example is a gas-liquid equilibrium propulsion system that uses liquefied gas as fuel. This system was mounted on the IKAROS solar sail and has been demonstrated in orbit. The system has a higher storage efficiency and a lighter configuration than a high-pressure cold-gas jet because the vapor pressure is lower, and is suitable for small spacecraft. However, the system requires a gas-liquid separation device in order to avoid leakage of the liquid, which makes the system complex. As another example of a phase equilibrium propulsion system, we introduce a solid-gas equilibrium propulsion system, which uses a sublimable substance as fuel and ejects its vapor. This system has an even lower vapor pressure and does not require such a separation device, instead requiring only a filter to keep the solid inside the tank. Moreover, the system is much simpler and lighter, making it more suitable for small spacecraft, especially CubeSat-class spacecraft, and the low thrust of the system allows spacecraft motion to be controlled precisely. In addition, the thrust level can be controlled by controlling the temperature of the fuel, which changes the vapor pressure. The present paper introduces the concept of the proposed system, and describes ejection experiments and its evaluation. The basic function of the proposed system is demonstrated in order to verify its usefulness.

  5. Spacecraft momentum control systems

    CERN Document Server

    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 ...

  6. Pi-Sat: A Low Cost Small Satellite and Distributed Spacecraft Mission System Test Platform

    Science.gov (United States)

    Cudmore, Alan

    2015-01-01

    Current technology and budget trends indicate a shift in satellite architectures from large, expensive single satellite missions, to small, low cost distributed spacecraft missions. At the center of this shift is the SmallSatCubesat architecture. The primary goal of the Pi-Sat project is to create a low cost, and easy to use Distributed Spacecraft Mission (DSM) test bed to facilitate the research and development of next-generation DSM technologies and concepts. This test bed also serves as a realistic software development platform for Small Satellite and Cubesat architectures. The Pi-Sat is based on the popular $35 Raspberry Pi single board computer featuring a 700Mhz ARM processor, 512MB of RAM, a flash memory card, and a wealth of IO options. The Raspberry Pi runs the Linux operating system and can easily run Code 582s Core Flight System flight software architecture. The low cost and high availability of the Raspberry Pi make it an ideal platform for a Distributed Spacecraft Mission and Cubesat software development. The Pi-Sat models currently include a Pi-Sat 1U Cube, a Pi-Sat Wireless Node, and a Pi-Sat Cubesat processor card.The Pi-Sat project takes advantage of many popular trends in the Maker community including low cost electronics, 3d printing, and rapid prototyping in order to provide a realistic platform for flight software testing, training, and technology development. The Pi-Sat has also provided fantastic hands on training opportunities for NASA summer interns and Pathways students.

  7. Development and Analysis of a Resource-Aware Power Management System as Applied to Small Spacecraft

    Energy Technology Data Exchange (ETDEWEB)

    Shriver, Patrick [Univ. of Colorado, Boulder, CO (United States)

    2005-01-01

    In this thesis, an overall framework and solution method for managing the limited power resources of a small spacecraft is presented. Analogous to mobile computing technology, a primary limiting factor is the available power resources. In spite of the millions of dollars budgeted for research and development over decades, improvements in battery efficiency remains low. This situation is exacerbated by advances in payload technology that lead to increasingly power-hungry and data-intensive instruments. The challenge for the small spacecraft is to maximize capabilities and performance while meeting difficult design requirements and small project budgets.

  8. Spacecraft radiator systems

    Science.gov (United States)

    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.

  9. Nano-Scale Sample Acquisition Systems for Small Class Exploration Spacecraft

    Science.gov (United States)

    Paulsen, G.

    2015-12-01

    The paradigm for space exploration is changing. Large and expensive missions are very rare and the space community is turning to smaller, lighter, and less expensive missions that could still perform great exploration. These missions are also within reach of commercial companies such as the Google Lunar X Prize teams that develop small scale lunar missions. Recent commercial endeavors such as "Planet Labs inc." and Sky Box Imaging, inc. show that there are new benefits and business models associated with miniaturization of space hardware. The Nano-Scale Sample Acquisition System includes NanoDrill for capture of small rock cores and PlanetVac for capture of surface regolith. These two systems are part of the ongoing effort to develop "Micro Sampling" systems for deployment by the small spacecraft with limited payload capacities. The ideal applications include prospecting missions to the Moon and Asteroids. The MicroDrill is a rotary-percussive coring drill that captures cores 7 mm in diameter and up to 2 cm long. The drill weighs less than 1 kg and can capture a core from a 40 MPa strength rock within a few minutes, with less than 10 Watt power and less than 10 Newton of preload. The PlanetVac is a pneumatic based regolith acquisition system that can capture surface sample in touch-and-go maneuver. These sampling systems were integrated within the footpads of commercial quadcopter for testing. As such, they could also be used by geologists on Earth to explore difficult to get to locations.

  10. The Core Flight System (cFS) Community: Providing Low Cost Solutions for Small Spacecraft

    Science.gov (United States)

    McComas, David; Wilmot, Jonathan; Cudmore, Alan

    2016-01-01

    In February 2015 the NASA Goddard Space Flight Center (GSFC) completed the open source release of the entire Core Flight Software (cFS) suite. After the open source release a multi-NASA center Configuration Control Board (CCB) was established that has managed multiple cFS product releases. The cFS was developed and is being maintained in compliance with the NASA Class B software development process requirements and the open source release includes all Class B artifacts. The cFS is currently running on three operational science spacecraft and is being used on multiple spacecraft and instrument development efforts. While the cFS itself is a viable flight software (FSW) solution, we have discovered that the cFS community is a continuous source of innovation and growth that provides products and tools that serve the entire FSW lifecycle and future mission needs. This paper summarizes the current state of the cFS community, the key FSW technologies being pursued, the development/verification tools and opportunities for the small satellite community to become engaged. The cFS is a proven high quality and cost-effective solution for small satellites with constrained budgets.

  11. Advancements of the Lightweight Integrated Solar Array and Transceiver (LISA-T) Small Spacecraft System

    Science.gov (United States)

    Lockett, Tiffany Russell; Martinez, Armando; Boyd, Darren; SanSouice, Michael; Farmer, Brandon; Schneider, Todd; Laue, Greg; Fabisinski, Leo; Johnson, Les; Carr, John A.

    2015-01-01

    This paper describes recent advancements of the Lightweight Integrated Solar Array and Transceiver (LISA-T) currently being developed at NASA's Marshall Space Flight Center. The LISA-T array comprises a launch stowed, orbit deployed structure on which thin-film photovoltaic (PV) and antenna devices are embedded. The system provides significant electrical power generation at low weights, high stowage efficiency, and without the need for solar tracking. Leveraging high-volume terrestrial-market PVs also gives the potential for lower array costs. LISA-T is addressing the power starvation epidemic currently seen by many small-scale satellites while also enabling the application of deployable antenna arrays. Herein, an overview of the system and its applications are presented alongside sub-system development progress and environmental testing plans.

  12. Hybrid spacecraft attitude control system

    Directory of Open Access Journals (Sweden)

    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.

  13. Hydrocarbon-Seeded Ignition System for Small Spacecraft Thrusters Using Ionic Liquid Propellants

    Science.gov (United States)

    Whitmore, Stephen A.; Merkley, Daniel P.; Eilers, Shannon D.; Taylor, Terry L.

    2013-01-01

    "Green" propellants based on Ionic-liquids (ILs) like Ammonium DiNitramide and Hydroxyl Ammonium Nitrate have recently been developed as reduced-hazard replacements for hydrazine. Compared to hydrazine, ILs offer up to a 50% improvement in available density-specific impulse. These materials present minimal vapor hazard at room temperature, and this property makes IL's potentially advantageous for "ride-share" launch opportunities where hazards introduced by hydrazine servicing are cost-prohibitive. Even though ILs present a reduced hazard compared to hydrazine, in crystalline form they are potentially explosive and are mixed in aqueous solutions to buffer against explosion. Unfortunately, the high water content makes IL-propellants difficult to ignite and currently a reliable "coldstart" capability does not exist. For reliable ignition, IL-propellants catalyst beds must be pre-heated to greater than 350 C before firing. The required preheat power source is substantial and presents a significant disadvantage for SmallSats where power budgets are extremely limited. Design and development of a "micro-hybrid" igniter designed to act as a "drop-in" replacement for existing IL catalyst beds is presented. The design requires significantly lower input energy and offers a smaller overall form factor. Unlike single-use "squib" pyrotechnic igniters, the system allows the gas generation cycle to be terminated and reinitiated on demand.

  14. Small Rocket/Spacecraft Technology (SMART) Platform

    Science.gov (United States)

    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.

  15. Printed Spacecraft Separation System

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. Small Spacecraft Technology Initiative Education Program

    Science.gov (United States)

    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.

  17. A small spacecraft for multipoint measurement of ionospheric plasma

    Science.gov (United States)

    Roberts, T. M.; Lynch, K. A.; Clayton, R. E.; Weiss, J.; Hampton, D. L.

    2017-07-01

    Measurement of ionospheric plasma is often performed by a single in situ device or remotely using cameras and radar. This article describes a small, low-resource, deployed spacecraft used as part of a local, multipoint measurement network. A B-field aligned sounding rocket ejects four of these spin-stabilized spacecraft in a cross pattern. In this application, each spacecraft carries two retarding potential analyzers which are used to determine plasma density, flow, and ion temperature. An inertial measurement unit and a light-emitting diode array are used to determine the position and orientation of the devices after deployment. The design of this spacecraft is first described, and then results from a recent test flight are discussed. This flight demonstrated the successful operation of the deployment mechanism and telemetry systems, provided some preliminary plasma measurements in a simple mid-latitude environment, and revealed several design issues.

  18. Small Spacecraft Constellation Concept for Mars Atmospheric Radio Occultations

    Science.gov (United States)

    Asmar, S. W.; Mannucci, A. J.; Ao, C. O.; Kobayashi, M. M.; Lazio, J.; Marinan, A.; Massone, G.; McCandless, S. E.; Preston, R. A.; Seubert, J.; Williamson, W.

    2017-12-01

    First demonstrated in 1965 when Mariner IV flew by Mars and determined the salient features of its atmosphere, radio occultation experiments have been carried out on numerous planetary missions with great discoveries. These experiments utilize the now classic configuration of a signal from a single planetary spacecraft to Earth receiving stations, where the science data are acquired. The Earth science community advanced the technique to utilizing a constellation of spacecraft with the radio occultation links between the spacecraft, enabled by the infrastructure of the Global Positioning System. With the advent of small and less costly spacecraft, such as planetary CubeSats and other variations, such as the anticipated innovative Mars Cube One mission, crosslinks among small spacecraft can be used to study other planets in the near future. Advantages of this type of experiment include significantly greater geographical coverage, which could reach global coverage over a few weeks with a small number of spacecraft. Repeatability of the global coverage can lead to examining temperature-pressure profiles and ionospheric electron density profiles, on daily, seasonal, annual, or other time scales of interest. The higher signal-to-noise ratio for inter-satellite links, compared to a link to Earth, decreases the design demands on the instrumentation (smaller antennas and transmitters, etc.). After an actual Mars crosslink demonstration, this concept has been in development using Mars as a possible target. Scientific objectives, delivery methods, operational scenarios and end-to-end configuration have been documented. Science objectives include determining the state and variability of the lower Martian atmosphere, which has been an identified as a high priority objective by the Mars Exploration Program Analysis Group, particularly as it relates to entry, descent, and landing and ascent for future crewed and robotic missions. This paper will present the latest research on the

  19. Hybrid spacecraft attitude control system

    OpenAIRE

    Renuganth Varatharajoo; Ramly Ajir; Tamizi Ahmad

    2016-01-01

    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...

  20. Spacecraft command and control using expert systems

    Science.gov (United States)

    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.

  1. Ulysses spacecraft control and monitoring system

    Science.gov (United States)

    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.

  2. Passive Plasma Contact Mechanisms for Small-Scale Spacecraft

    Science.gov (United States)

    McTernan, Jesse K.

    Small-scale spacecraft represent a paradigm shift in how entities such as academia, industry, engineering firms, and the scientific community operate in space. However, although the paradigm shift produces unique opportunities to build satellites in unique ways for novel missions, there are also significant challenges that must be addressed. This research addresses two of the challenges associated with small-scale spacecraft: 1) the miniaturization of spacecraft and associated instrumentation and 2) the need to transport charge across the spacecraft-environment boundary. As spacecraft decrease in size, constraints on the size, weight, and power of on-board instrumentation increase--potentially limiting the instrument's functionality or ability to integrate with the spacecraft. These constraints drive research into mechanisms or techniques that use little or no power and efficiently utilize existing resources. One limited resource on small-scale spacecraft is outer surface area, which is often covered with solar panels to meet tight power budgets. This same surface area could also be needed for passive neutralization of spacecraft charging. This research explores the use of a transparent, conductive layer on the solar cell coverglass that is electrically connected to spacecraft ground potential. This dual-purpose material facilitates the use of outer surfaces for both energy harvesting of solar photons as well as passive ion collection. Mission capabilities such as in-situ plasma measurements that were previously infeasible on small-scale platforms become feasible with the use of indium tin oxide-coated solar panel coverglass. We developed test facilities that simulate the space environment in low Earth orbit to test the dual-purpose material and the various application of this approach. Particularly, this research is in support of two upcoming missions: OSIRIS-3U, by Penn State's Student Space Programs Lab, and MiTEE, by the University of Michigan. The purpose of

  3. Spacecraft Multiple Array Communication System Performance Analysis

    Science.gov (United States)

    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.

  4. Thrusting maneuver control of a small spacecraft via only gimbaled-thruster scheme

    Science.gov (United States)

    Kabganian, Mansour; Kouhi, Hamed; Shahravi, Morteza; Fani Saberi, Farhad

    2018-05-01

    The thrust vector control (TVC) scheme is a powerful method in spacecraft attitude control. Since the control of a small spacecraft is being studied here, a solid rocket motor (SRM) should be used instead of a liquid propellant motor. Among the TVC methods, gimbaled-TVC as an efficient method is employed in this paper. The spacecraft structure is composed of a body and a gimbaled-SRM where common attitude control systems such as reaction control system (RCS) and spin-stabilization are not presented. A nonlinear two-body model is considered for the characterization of the gimbaled-thruster spacecraft where, the only control input is provided by a gimbal actuator. The attitude of the spacecraft is affected by a large exogenous disturbance torque which is generated by a thrust vector misalignment from the center of mass (C.M). A linear control law is designed to stabilize the spacecraft attitude while rejecting the mentioned disturbance torque. A semi-analytical formulation of the region of attraction (RoA) is developed to ensure the local stability and fast convergence of the nonlinear closed-loop system. Simulation results of the 3D maneuvers are included to show the applicability of this method for use in a small spacecraft.

  5. Attitude Estimation in Fractionated Spacecraft Cluster Systems

    Science.gov (United States)

    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.

  6. Managing Small Spacecraft Projects: Less is Not Easier

    Science.gov (United States)

    Barley, Bryan; Newhouse, Marilyn

    2012-01-01

    Managing small, low cost missions (class C or D) is not necessarily easier than managing a full flagship mission. Yet, small missions are typically considered easier to manage and used as a training ground for developing the next generation of project managers. While limited resources can be a problem for small missions, in reality most of the issues inherent in managing small projects are not the direct result of limited resources. Instead, problems encountered by managers of small spacecraft missions often derive from 1) the perception that managing small projects is easier if something is easier it needs less rigor and formality in execution, 2) the perception that limited resources necessitate or validate omitting standard management practices, 3) less stringent or unclear guidelines or policies for small projects, and 4) stakeholder expectations that are not consistent with the size and nature of the project. For example, the size of a project is sometimes used to justify not building a full, detailed integrated master schedule. However, while a small schedule slip may not be a problem for a large mission, it can indicate a serious problem for a small mission with a short development phase, highlighting the importance of the schedule for early identification of potential issues. Likewise, stakeholders may accept a higher risk posture early in the definition of a low-cost mission, but as launch approaches this acceptance may change. This presentation discusses these common misconceptions about managing small, low cost missions, the problems that can result, and possible solutions.

  7. Developing Sustainable Spacecraft Water Management Systems

    Science.gov (United States)

    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.

  8. Artificial Intelligence and Spacecraft Power Systems

    Science.gov (United States)

    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.

  9. Electrical design for origami solar panels and a small spacecraft test mission

    Science.gov (United States)

    Drewelow, James; Straub, Jeremy

    2017-05-01

    Efficient power generation is crucial to the design of spacecraft. Mass, volume, and other limitations prevent the use of traditional spacecraft support structures from being suitable for the size of solar array required for some missions. Folding solar panel / panel array systems, however, present a number of design challenges. This paper considers the electrical design of an origami system. Specifically, it considers how to provide low impedance, durable channels for the generated power and the electrical aspects of the deployment system and procedure. The ability to dynamically reconfigure the electrical configuration of the solar cells is also discussed. Finally, a small satellite test mission to demonstrate the technology is proposed, before concluding.

  10. Manned spacecraft electrical power systems

    Science.gov (United States)

    Simon, William E.; Nored, Donald L.

    1987-01-01

    A brief history of the development of electrical power systems from the earliest manned space flights illustrates a natural trend toward a growth of electrical power requirements and operational lifetimes with each succeeding space program. A review of the design philosophy and development experience associated with the Space Shuttle Orbiter electrical power system is presented, beginning with the state of technology at the conclusion of the Apollo Program. A discussion of prototype, verification, and qualification hardware is included, and several design improvements following the first Orbiter flight are described. The problems encountered, the scientific and engineering approaches used to meet the technological challenges, and the results obtained are stressed. Major technology barriers and their solutions are discussed, and a brief Orbiter flight experience summary of early Space Shuttle missions is included. A description of projected Space Station power requirements and candidate system concepts which could satisfy these anticipated needs is presented. Significant challenges different from Space Shuttle, innovative concepts and ideas, and station growth considerations are discussed. The Phase B Advanced Development hardware program is summarized and a status of Phase B preliminary tradeoff studies is presented.

  11. Wheel speed management control system for spacecraft

    Science.gov (United States)

    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.

  12. Discovering the cosmos with small spacecraft the American explorer program

    CERN Document Server

    Harvey, Brian

    2018-01-01

    Explorer was the original American space program and Explorer 1 its first satellite, launched in 1958. Sixty years later, it is the longest continuously running space program in the world, demonstrating to the world how we can explore the cosmos with small spacecraft. Almost a hundred Explorers have already been launched.  Explorers have made some of the fundamental discoveries of the Space Age.Explorer 1 discovered Earth’s radiation belts. Later Explorers surveyed the Sun, the X-ray and ultraviolet universes, black holes, magnetars and gamma ray bursts. An Explorer found the remnant of the Big Bang. One Explorer chased and was the first to intercept a comet. The program went through a period of few launches during the crisis of funding for space science in the 1980s. However, with the era of ‘faster, cheaper, better,’ the program was reinvented, and new exiting missions began to take shape, like Swift and the asteroid hunter WISE.  Discovering the Cosmos with Small Spacecraft gives an account of ...

  13. Protecting Spacecraft Fragments from Exposure to Small Debris

    Directory of Open Access Journals (Sweden)

    V. V. Zelentsov

    2015-01-01

    Full Text Available Since the launch of the first artificial Earth satellite a large amount of space debris has been accumulated in near-earth space. This debris comprises the exhausted spacecrafts, final stages of rocket-carriers and boosters, technological space junk, consisting of the structure elements, which are separated when deploying the solar arrays, antennas etc., as well as when undocking a booster and a spacecraft. All the debris is divided into observable one of over 100 mm in size and unobservable debris. In case of possible collision with the observed debris an avoidance manoeuvre is provided. The situation with unobservable debris is worse, its dimensions ranging from 100 mm to several microns. This debris is formed as a result of explosions of dead space objects and at collisions of destroyed spacecraft fragments against each other. This debris moves along arbitrary trajectories at different speeds.At collision of a spacecraft with fragments of small-size space debris, various consequences are possible: the device can immediately fail, suffer damages, which will have effect later and damages, which break no bones to the aircraft. Anyway, the spacecraft collision with small-size debris particles is undesirable. The protective shields are used to protect the aircraft from damage. Development of shield construction is complicated because the high cost of launch makes it impossible to conduct field tests of shields in space. All the work is carried out in the laboratory, with particles having co-impact speeds up to 10 km/s (possible speeds are up to 20 km/s and spherically shaped particles of 0.8 ... 3 mm in diameter.Various materials are used to manufacture shields. These are aluminum sheet, sandwich panels, metal mesh, metal foam, and woven materials (ballistic fabric. The paper considers single-layer (from sheet metal sandwich materials and multilayer shield designs. As experimental studies show, a single-layer shield protects colliding at speeds

  14. Galileo spacecraft power management and distribution system

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  16. Protecting Spacecraft Fragments from Exposure to Small Debris

    OpenAIRE

    V. V. Zelentsov

    2015-01-01

    Since the launch of the first artificial Earth satellite a large amount of space debris has been accumulated in near-earth space. This debris comprises the exhausted spacecrafts, final stages of rocket-carriers and boosters, technological space junk, consisting of the structure elements, which are separated when deploying the solar arrays, antennas etc., as well as when undocking a booster and a spacecraft. All the debris is divided into observable one of over 100 mm in size and unobservable ...

  17. Investigation of fast initialization of spacecraft bubble memory systems

    Science.gov (United States)

    Looney, K. T.; Nichols, C. D.; Hayes, P. J.

    1984-01-01

    Bubble domain technology offers significant improvement in reliability and functionality for spacecraft onboard memory applications. In considering potential memory systems organizations, minimization of power in high capacity bubble memory systems necessitates the activation of only the desired portions of the memory. In power strobing arbitrary memory segments, a capability of fast turn on is required. Bubble device architectures, which provide redundant loop coding in the bubble devices, limit the initialization speed. Alternate initialization techniques are investigated to overcome this design limitation. An initialization technique using a small amount of external storage is demonstrated.

  18. Modeling the angular motion dynamics of spacecraft with a magnetic attitude control system based on experimental studies and dynamic similarity

    Science.gov (United States)

    Kulkov, V. M.; Medvedskii, A. L.; Terentyev, V. V.; Firsyuk, S. O.; Shemyakov, A. O.

    2017-12-01

    The problem of spacecraft attitude control using electromagnetic systems interacting with the Earth's magnetic field is considered. A set of dimensionless parameters has been formed to investigate the spacecraft orientation regimes based on dynamically similar models. The results of experimental studies of small spacecraft with a magnetic attitude control system can be extrapolated to the in-orbit spacecraft motion control regimes by using the methods of the dimensional and similarity theory.

  19. LQG/LTR optimal attitude control of small flexible spacecraft using free-free boundary conditions

    Science.gov (United States)

    Fulton, Joseph M.

    Due to the volume and power limitations of a small satellite, careful consideration must be taken while designing an attitude control system for 3-axis stabilization. Placing redundancy in the system proves difficult and utilizing power hungry, high accuracy, active actuators is not a viable option. Thus, it is customary to find dependable, passive actuators used in conjunction with small scale active control components. This document describes the application of Elastic Memory Composite materials in the construction of a flexible spacecraft appendage, such as a gravity gradient boom. Assumed modes methods are used with Finite Element Modeling information to obtain the equations of motion for the system while assuming free-free boundary conditions. A discussion is provided to illustrate how cantilever mode shapes are not always the best assumption when modeling small flexible spacecraft. A key point of interest is first resonant modes may be needed in the system design plant in spite of these modes being greater than one order of magnitude in frequency when compared to the crossover frequency of the controller. LQG/LTR optimal control techniques are implemented to compute attitude control gains while controller robustness considerations determine appropriate reduced order controllers and which flexible modes to include in the design model. Key satellite designer concerns in the areas of computer processor sizing, material uncertainty impacts on the system model, and system performance variations resulting from appendage length modifications are addressed.

  20. Spacecraft attitude and velocity control system

    Science.gov (United States)

    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.

  1. Low power arcjet system spacecraft impacts

    Science.gov (United States)

    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.

  2. Radioisotope AMTEC power system designs for spacecraft applications

    International Nuclear Information System (INIS)

    Ivanenok, J.F. III; Sievers, R.K.; Hunt, T.K.; Johnson, G.A.

    1993-01-01

    The Alkali Metal Thermal to Electric Converter (AMTEC) system is an exceptional candidate for high performance spacecraft power systems including small systems powered by General Purpose Heat Sources (GPHS). The AMTEC converter is best described as a thermally regenerative electrochemical concentration cell. AMTEC is a static energy conversion device and can operate at efficiencies between 15% and 30%. The single tube, remote condensed, wick return minicell design has been incorporated into a radioisotope powered system model. Reported cell efficiencies used for these system design studies ranged from 15% to 25%. This efficiency is significantly higher than other static conversion systems operating at the same temperatures. Savings in mass and cost, relative to other more conventional static conversion systems, have also been shown. The minicell used for this system study has many advanced features not combined in previous designs, including wick return, remote condensing, and hot zone feedthroughs. All of these features significantly enhance the performance of the AMTEC cell. Additionally, the cell end provides enough area for adequate heat transfer from the GPHS module, eliminating the need for a ''hot shoe'', and reducing the complexity and weight of the system. This paper describes and compares small (two module) and larger (16 module) AMTEC radioisotope powered systems and describes the computer model developed to predict their performance

  3. Conceptual definition of Automated Power Systems Management. [for planetary spacecraft

    Science.gov (United States)

    Imamura, M. S.; Skelly, L.; Weiner, H.

    1977-01-01

    Automated Power Systems Management (APSM) is defined as the capability of a spacecraft power system to automatically perform monitoring, computational, command, and control functions without ground intervention. Power systems for future planetary spacecraft must have this capability because they must perform up to 10 years, and accommodate real-time changes in mission execution autonomously. Specific APSM functions include fault detection, isolation, and correction; system performance and load profile prediction; power system optimization; system checkout; and data storage and transmission control. This paper describes the basic method of implementing these specific functions. The APSM hardware includes a central power system computer and a processor dedicated to each major power system subassembly along with digital interface circuitry. The major payoffs anticipated are in enhancement of spacecraft reliability and life and reduction of overall spacecraft program cost.

  4. Enabling Advanced Automation in Spacecraft Operations with the Spacecraft Emergency Response System

    Science.gov (United States)

    Breed, Julie; Fox, Jeffrey A.; Powers, Edward I. (Technical Monitor)

    2001-01-01

    True autonomy is the Holy Grail of spacecraft mission operations. The goal of launching a satellite and letting it manage itself throughout its useful life is a worthy one. With true autonomy, the cost of mission operations would be reduced to a negligible amount. Under full autonomy, any problems (no matter the severity or type) that may arise with the spacecraft would be handled without any human intervention via some combination of smart sensors, on-board intelligence, and/or smart automated ground system. Until the day that complete autonomy is practical and affordable to deploy, incremental steps of deploying ever-increasing levels of automation (computerization of once manual tasks) on the ground and on the spacecraft are gradually decreasing the cost of mission operations. For example, NASA's Goddard Space Flight Center (NASA-GSFC) has been flying spacecraft with low cost operations for several years. NASA-GSFC's SMEX (Small Explorer) and MIDEX (Middle Explorer) missions have effectively deployed significant amounts of automation to enable the missions to fly predominately in 'light-out' mode. Under light-out operations the ground system is run without human intervention. Various tools perform many of the tasks previously performed by the human operators. One of the major issues in reducing human staff in favor of automation is the perceived increased in risk of losing data, or even losing a spacecraft, because of anomalous conditions that may occur when there is no one in the control center. When things go wrong, missions deploying advanced automation need to be sure that anomalous conditions are detected and that key personal are notified in a timely manner so that on-call team members can react to those conditions. To ensure the health and safety of its lights-out missions, NASA-GSFC's Advanced Automation and Autonomy branch (Code 588) developed the Spacecraft Emergency Response System (SERS). The SERS is a Web-based collaborative environment that enables

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

    Science.gov (United States)

    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.

  6. Research on intelligent power distribution system for spacecraft

    Science.gov (United States)

    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.

  7. A Study of Learning Curve Impact on Three Identical Small Spacecraft

    Science.gov (United States)

    Chen, Guangming; McLennan, Douglas D.

    2003-01-01

    With an eye to the future strategic needs of NASA, the New Millennium Program is funding the Space Technology 5 (ST-5) project to address the future needs in the area of small satellites in constellation missions. The ST-5 project, being developed at Goddard Space Flight Center, involves the development and simultaneous launch of three small, 20-kilogram-class spacecraft. ST-5 is only a test drive and future NASA science missions may call for fleets of spacecraft containing tens of smart and capable satellites in an intelligent constellation. The objective of ST-5 project is to develop three such pioneering small spacecraft for flight validation of several critical new technologies. The ST-5 project team at Goddard Space Flight Center has completed the spacecraft design, is now building and testing the three flight units. The launch readiness date (LRD) is in December 2005. A critical part of ST-5 mission is to prove that it is possible to build these small but capable spacecraft with recurring cost low enough to make future NASA s multi- spacecraft constellation missions viable from a cost standpoint.

  8. Diagnosing Faults in Electrical Power Systems of Spacecraft and Aircraft

    Data.gov (United States)

    National Aeronautics and Space Administration — Electrical power systems play a critical role in spacecraft and aircraft, and they exhibit a rich variety of failure modes. This paper discusses electrical power...

  9. High precision relative position sensing system for formation flying spacecraft

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop and test an optical sensing system that provides high precision relative position sensing for formation flying spacecraft.  A high precision...

  10. Time maintenance system for the BMDO MSX spacecraft

    Science.gov (United States)

    Hermes, Martin J.

    1994-01-01

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

  11. The Small Mars System

    Science.gov (United States)

    Fantino, E.; Grassi, M.; Pasolini, P.; Causa, F.; Molfese, C.; Aurigemma, R.; Cimminiello, N.; de la Torre, D.; Dell'Aversana, P.; Esposito, F.; Gramiccia, L.; Paudice, F.; Punzo, F.; Roma, I.; Savino, R.; Zuppardi, G.

    2017-08-01

    The Small Mars System is a proposed mission to Mars. Funded by the European Space Agency, the project has successfully completed Phase 0. The contractor is ALI S.c.a.r.l., and the study team includes the University of Naples ;Federico II;, the Astronomical Observatory of Capodimonte and the Space Studies Institute of Catalonia. The objectives of the mission are both technological and scientific, and will be achieved by delivering a small Mars lander carrying a dust particle analyser and an aerial drone. The former shall perform in situ measurements of the size distribution and abundance of dust particles suspended in the Martian atmosphere, whereas the latter shall demonstrate low-altitude flight in the rarefied planetary environment. The mission-enabling technology is an innovative umbrella-like heat shield, known as IRENE, developed and patented by ALI. The mission is also a technological demonstration of the shield in the upper atmosphere of Mars. The core characteristics of SMS are the low cost (120 M€) and the small size (320 kg of wet mass at launch, 110 kg at landing), features which stand out with respect to previous Mars landers. To comply with them is extremely challenging at all levels, and sets strict requirements on the choice of the materials, the sizing of payloads and subsystems, their arrangement inside the spacecraft and the launcher's selection. In this contribution, the mission and system concept and design are illustrated and discussed. Special emphasis is given to the innovative features and to the challenges faced in the development of the work.

  12. Mean of Microaccelerations Estimate in the Small Spacecraft Internal Environment with the Use of Fuzzy Sets

    Science.gov (United States)

    Sedelnikov, A. V.

    2018-05-01

    Assessment of parameters of rotary motion of the small spacecraft around its center of mass and of microaccelerations using measurements of current from silicon photocells is carried out. At the same time there is a problem of interpretation of ambiguous telemetric data. Current from two opposite sides of the small spacecraft is significant. The mean of removal of such uncertainty is considered. It is based on an fuzzy set. As membership function it is offered to use a normality condition of the direction cosines. The example of uncertainty removal for a prototype of the Aist small spacecraft is given. The offered approach can significantly increase the accuracy of microaccelerations estimate when using measurements of current from silicon photocells.

  13. Ka-band Technologies for Small Spacecraft Communications via Relays and Direct Data Downlink

    Science.gov (United States)

    Budinger, James M.; Niederhaus, Charles; Reinhart, Richard; Downey, Joe; Roberts, Anthony

    2016-01-01

    As the scientific capabilities and number of small spacecraft missions in the near Earth region increase, standard yet configurable user spacecraft terminals operating in Ka-band are needed to lower mission cost and risk and enable significantly higher data return than current UHF or S-band terminals. These compact Ka-band terminals are intended to operate with both the current and next generation of Ka-band relay satellites and via direct data communications with near Earth tracking terminals. This presentation provides an overview of emerging NASA-sponsored and commercially provided technologies in software defined radios (SDRs), transceivers, and electronically steered antennas that will enable data rates from hundreds of kbps to over 1 Gbps and operate in multiple frequency bands (such as S- and X-bands) and expand the use of NASA's common Ka-bands frequencies: 22.55-23.15 GHz for forward data or uplink; and 25.5-27.0 GHz for return data or downlink. Reductions in mass, power and volume come from integration of multiple radio functions, operations in Ka-band, high efficiency amplifiers and receivers, and compact, flat and vibration free electronically steered narrow beam antennas for up to + 60 degrees field of regard. The software defined near Earth space transceiver (SD-NEST) described in the presentation is intended to be compliant with NASA's space telecommunications radio system (STRS) standard for communications waveforms and hardware interoperability.

  14. Multi-kilowatt modularized spacecraft power processing system development

    International Nuclear Information System (INIS)

    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

  15. PHOBOS Exploration using Two Small Solar Electric Propulsion (SEP) Spacecraft

    Science.gov (United States)

    Lang, J. J.; Baker, J. D.; McElrath, T. P.; Piacentine, J. S.; Snyder, J. S.

    2012-01-01

    Phobos Surveyor Mission concept provides an innovative low cost, highly reliable approach to exploring the inner solar system 1/16/2013 3 Dual manifest launch. Use only flight proven, well characterize commercial off-the-shelf components. Flexible mission architecture allows for a slew of unique measurements.

  16. Miniaturized digital fluxgate magnetometer for small spacecraft applications

    International Nuclear Information System (INIS)

    Forslund, Åke; Ivchenko, Nickolay; Olsson, Göran; Edberg, Terry; Belyayev, Serhiy; Marusenkov, Andriy

    2008-01-01

    A novel design of an Earth field digital fluxgate magnetometer is presented, the small magnetometer in low-mass experiment (SMILE). The combination of a number of new techniques results in significant miniaturization of both sensor and electronics. The design uses a sensor with volume compensation, combining three dual rod cores in a Macor® cube with the side dimension of 20 mm. Use of volume compensation provides high geometrical stability of the axes and improved performance compared to component compensated sensors. The sensor is operated at an excitation frequency of 8 kHz. Most of the instrument functionality is combined in a digital signal processing core, implemented in a field programmable gate array (FPGA). The pick-up signal is digitized after amplification and filtering, and values of compensation currents for each of the axes are determined by a digital correlation algorithm, equivalent to a matched filter, and are fed to a hybrid pulse-width modulation/delta-sigma digital-to-analogue converter driving the currents through the compensation coils. Using digital design makes the instrument very flexible, reduces power consumption and opens possibilities for the customization of the operation modes. The current implementation of the design is based on commercial off-the-shelf components. A calibration of the SMILE instrument was carried out at the Nurmijärvi Geophysical Observatory, showing high linearity (within 6 nT on the whole ±50 µT scale), good orthogonality (22 arcmin) and very good temperature stability of the axes

  17. A Shaftless Magnetically Levitated Multifunctional Spacecraft Flywheel Storage System

    Science.gov (United States)

    Stevens, Ken; Thornton, Richard; Clark, Tracy; Beaman, Bob G.; Dennehy, Neil; Day, John H. (Technical Monitor)

    2002-01-01

    Presently many types of spacecraft use a Spacecraft Attitude Control System (ACS) with momentum wheels for steering and electrochemical batteries to provide electrical power for the eclipse period of the spacecraft orbit. Future spacecraft will use Flywheels for combined use in ACS and Energy Storage. This can be done by using multiple wheels and varying the differential speed for ACS and varying the average speed for energy storage and recovery. Technology in these areas has improved since the 1990s so it is now feasible for flywheel systems to emerge from the laboratory for spacecraft use. This paper describes a new flywheel system that can be used for both ACS and energy storage. Some of the possible advantages of a flywheel system are: lower total mass and volume, higher efficiency, less thermal impact, improved satellite integration schedule and complexity, simplified satellite orbital operations, longer life with lower risk, less pointing jitter, and greater capability for high-rate slews. In short, they have the potential to enable new types of missions and provide lower cost. Two basic types of flywheel configurations are the Flywheel Energy Storage System (FESS) and the Integrated Power and Attitude Control System (IPACS).

  18. Automating a spacecraft electrical power system using expert systems

    Science.gov (United States)

    Lollar, L. F.

    1991-01-01

    Since Skylab, Marshall Space Flight Center (MSFC) has recognized the need for large electrical power systems (EPS's) in upcoming Spacecraft. The operation of the spacecraft depends on the EPS. Therefore, it must be efficient, safe, and reliable. In 1978, as a consequence of having to supply a large number of EPS personnel to monitor and control Skylab, the Electrical power Branch of MSFC began the autonomously managed power system (AMPS) project. This project resulted in the assembly of a 25-kW high-voltage dc test facility and provided the means of getting man out of the loop as much as possible. AMPS includes several embedded controllers which allow a significant level of autonomous operation. More recently, the Electrical Division at MSFC has developed the space station module power management and distribution (SSM/PMAD) breadboard to investigate managing and distributing power in the Space Station Freedom habitation and laboratory modules. Again, the requirement for a high level of autonomy for the efficient operation over the lifetime of the station and for the benefits of enhanced safety has been demonstrated. This paper describes the two breadboards and the hierarchical approach to automation which was developed through these projects.

  19. Large autonomous spacecraft electrical power system (LASEPS)

    Science.gov (United States)

    Dugal-Whitehead, Norma R.; Johnson, Yvette B.

    1992-01-01

    NASA - Marshall Space Flight Center is creating a large high voltage electrical power system testbed called LASEPS. This testbed is being developed to simulate an end-to-end power system from power generation and source to loads. When the system is completed it will have several power configurations, which will include several battery configurations. These configurations are: two 120 V batteries, one or two 150 V batteries, and one 250 to 270 V battery. This breadboard encompasses varying levels of autonomy from remote power converters to conventional software control to expert system control of the power system elements. In this paper, the construction and provisions of this breadboard are discussed.

  20. Radioisotope heaters for spacecraft life support systems

    International Nuclear Information System (INIS)

    Shivers, R.W.; Murray, R.W.

    1974-01-01

    Future manned space flight requires the sanitary collection and disposal of biological wastes to minimize microbial contamination hazard. The recovery and reuse of water from such wastes are also necessary to reduce the weight of vehicles at launching and resupply logistics. The development and test of an engineering model, i.e. the completely integrated waste management-water system using radioisotopes for thermal energy, are described. This is capable of collecting and processing the wastes from four men during 180-day simulated space mission. The sub-systems include collection of feces, trash and urine, water reclamation, the storage, heating and dispensing of the water, and the disposal of feces, urine residue and other non-metallic waste material by incineration. (Mori, K.)

  1. Five Fabulous Flybys of the Small Inner Moons of Saturn by the Cassini Spacecraft

    Science.gov (United States)

    Buratti, B. J.; Momary, T.; Clark, R. N.; Brown, R. H.; Filacchione, G.; Mosher, J. A.; Baines, K. H.; Nicholson, P. D.

    2017-12-01

    The Saturn system possesses a number of small unique moons, including the coorbitals Janus and Epimetheus; the ring moons Pan and Daphnis; and Prometheus, Pandora, and Atlas, which orbit near the edge of the main ring system. During the last phases of the Cassini mission, when the spacecraft executed close passes to the F-ring of Saturn, five "best-ever" flybys of these moons occurred. Pan, Daphnis, Atlas, Pandora, and Epimetheus were approached at distances ranging from 6000-40,000 km. The Visual Infrared Mapping Spectrometer (VIMS) captured data from the spectral range spanning 0.35-5.1 microns, as well as capturing solar phase angles not observed before. When combined with spectra from different regions of the moons obtained throughout the mission, the VIMS observations reveal substantial changes in the depth of water-ice absorption bands and color over the moons' surfaces. These measurements show the accretion of main-ring material onto the moons, with leading sides exhibiting stronger water-ice signatures in general. Atlas and Pandora have red visible spectra similar to the A-ring and unlike other icy moons, which are blue, further revealing accretion of main ring material onto the small inner moons. In general the visible spectra of the moons gets bluer with distance from Saturn until the surface of the moons is dominated by contamination from the E-ring, which is composed of fresh ice. There is a weak correlation between color and albedo, with lower-albedo moons being redder, suggesting the existence of a dark reddish contaminant from the main ring system. The solar phase curves of the moons are similar to those of larger icy moons (unfortunately no opposition surge data was gathered). 2017 California Institute of Technology. Government sponsorship acknowledged.

  2. An Expert System for Autonomous Spacecraft Control

    Science.gov (United States)

    Sherwood, Rob; Chien, Steve; Tran, Daniel; Cichy, Benjamin; Castano, Rebecca; Davies, Ashley; Rabideau, Gregg

    2005-01-01

    The Autonomous Sciencecraft Experiment (ASE), part of the New Millennium Space Technology 6 Project, is flying onboard the Earth Orbiter 1 (EO-1) mission. The ASE software enables EO-1 to autonomously detect and respond to science events such as: volcanic activity, flooding, and water freeze/thaw. ASE uses classification algorithms to analyze imagery onboard to detect chang-e and science events. Detection of these events is then used to trigger follow-up imagery. Onboard mission planning software then develops a response plan that accounts for target visibility and operations constraints. This plan is then executed using a task execution system that can deal with run-time anomalies. In this paper we describe the autonomy flight software and how it enables a new paradigm of autonomous science and mission operations. We will also describe the current experiment status and future plans.

  3. The Earth Observing System AM Spacecraft - Thermal Control Subsystem

    Science.gov (United States)

    Chalmers, D.; Fredley, J.; Scott, C.

    1993-01-01

    Mission requirements for the EOS-AM Spacecraft intended to monitor global changes of the entire earth system are considered. The spacecraft is based on an instrument set containing the Advanced Spaceborne Thermal Emission and Reflection radiometer (ASTER), Clouds and Earth's Radiant Energy System (CERES), Multiangle Imaging Spectro-Radiometer (MISR), Moderate-Resolution Imaging Spectrometer (MODIS), and Measurements of Pollution in the Troposphere (MOPITT). Emphasis is placed on the design, analysis, development, and verification plans for the unique EOS-AM Thermal Control Subsystem (TCS) aimed at providing the required environments for all the onboard equipment in a densely packed layout. The TCS design maximizes the use of proven thermal design techniques and materials, in conjunction with a capillary pumped two-phase heat transport system for instrument thermal control.

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

    Science.gov (United States)

    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.

  5. Small test SDHW systems

    DEFF Research Database (Denmark)

    Vejen, Niels Kristian

    1999-01-01

    Three small test SDHW systems was tested in a laboratory test facility.The three SDHW systems where all based on the low flow principe and a mantle tank but the design of the systems where different.......Three small test SDHW systems was tested in a laboratory test facility.The three SDHW systems where all based on the low flow principe and a mantle tank but the design of the systems where different....

  6. Air Purification in Closed Environments: An Overview of Spacecraft Systems

    Science.gov (United States)

    Perry, Jay L.; LeVan, Douglas; Crumbley, Robert (Technical Monitor)

    2002-01-01

    The primary goal for a collective protection system and a spacecraft environmental control and life support system (ECLSS) are strikingly similar. Essentially both function to provide the occupants of a building or vehicle with a safe, habitable environment. The collective protection system shields military and civilian personnel from short-term exposure to external threats presented by toxic agents and industrial chemicals while an ECLSS sustains astronauts for extended periods within the hostile environment of space. Both have air quality control similarities with various aircraft and 'tight' buildings. This paper reviews basic similarities between air purification system requirements for collective protection and an ECLSS that define surprisingly common technological challenges and solutions. Systems developed for air revitalization on board spacecraft are discussed along with some history on their early development as well as a view of future needs. Emphasis is placed upon two systems implemented by the National Aeronautics and Space Administration (NASA) onboard the International Space Station (ISS): the trace contaminant control system (TCCS) and the molecular sieve-based carbon dioxide removal assembly (CDRA). Over its history, the NASA has developed and implemented many life support systems for astronauts. As the duration, complexity, and crew size of manned missions increased from minutes or hours for a single astronaut during Project Mercury to days and ultimately months for crews of 3 or more during the Apollo, Skylab, Shuttle, and ISS programs, these systems have become more sophisticated. Systems aboard spacecraft such as the ISS have been designed to provide long-term environmental control and life support. Challenges facing the NASA's efforts include minimizing mass, volume, and power for such systems, while maximizing their safety, reliability, and performance. This paper will highlight similarities and differences among air purification systems

  7. Spacecraft System Integration and Test: SSTI Lewis critical design audit

    Science.gov (United States)

    Brooks, R. P.; Cha, K. K.

    1995-01-01

    The Critical Design Audit package is the final detailed design package which provides a comprehensive description of the SSTI mission. This package includes the program overview, the system requirements, the science and applications activities, the ground segment development, the assembly, integration and test description, the payload and technology demonstrations, and the spacecraft bus subsystems. Publication and presentation of this document marks the final requirements and design freeze for SSTI.

  8. Artificial intelligence costs, benefits, and risks for selected spacecraft ground system automation scenarios

    Science.gov (United States)

    Truszkowski, Walter F.; Silverman, Barry G.; Kahn, Martha; Hexmoor, Henry

    1988-01-01

    In response to a number of high-level strategy studies in the early 1980s, expert systems and artificial intelligence (AI/ES) efforts for spacecraft ground systems have proliferated in the past several years primarily as individual small to medium scale applications. It is useful to stop and assess the impact of this technology in view of lessons learned to date, and hopefully, to determine if the overall strategies of some of the earlier studies both are being followed and still seem relevant. To achieve that end four idealized ground system automation scenarios and their attendant AI architecture are postulated and benefits, risks, and lessons learned are examined and compared. These architectures encompass: (1) no AI (baseline); (2) standalone expert systems; (3) standardized, reusable knowledge base management systems (KBMS); and (4) a futuristic unattended automation scenario. The resulting artificial intelligence lessons learned, benefits, and risks for spacecraft ground system automation scenarios are described.

  9. Artificial intelligence costs, benefits, risks for selected spacecraft ground system automation scenarios

    Science.gov (United States)

    Truszkowski, Walter F.; Silverman, Barry G.; Kahn, Martha; Hexmoor, Henry

    1988-01-01

    In response to a number of high-level strategy studies in the early 1980s, expert systems and artificial intelligence (AI/ES) efforts for spacecraft ground systems have proliferated in the past several years primarily as individual small to medium scale applications. It is useful to stop and assess the impact of this technology in view of lessons learned to date, and hopefully, to determine if the overall strategies of some of the earlier studies both are being followed and still seem relevant. To achieve that end four idealized ground system automation scenarios and their attendant AI architecture are postulated and benefits, risks, and lessons learned are examined and compared. These architectures encompass: (1) no AI (baseline), (2) standalone expert systems, (3) standardized, reusable knowledge base management systems (KBMS), and (4) a futuristic unattended automation scenario. The resulting artificial intelligence lessons learned, benefits, and risks for spacecraft ground system automation scenarios are described.

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

    Science.gov (United States)

    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

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

    National Research Council Canada - National Science Library

    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...

  12. Advanced Deployable Structural Systems for Small Satellites

    Science.gov (United States)

    Belvin, W. Keith; Straubel, Marco; Wilkie, W. Keats; Zander, Martin E.; Fernandez, Juan M.; Hillebrandt, Martin F.

    2016-01-01

    One of the key challenges for small satellites is packaging and reliable deployment of structural booms and arrays used for power, communication, and scientific instruments. The lack of reliable and efficient boom and membrane deployment concepts for small satellites is addressed in this work through a collaborative project between NASA and DLR. The paper provides a state of the art overview on existing spacecraft deployable appendages, the special requirements for small satellites, and initial concepts for deployable booms and arrays needed for various small satellite applications. The goal is to enhance deployable boom predictability and ground testability, develop designs that are tolerant of manufacturing imperfections, and incorporate simple and reliable deployment systems.

  13. Study of reactor Brayton power systems for nuclear electric spacecraft

    Science.gov (United States)

    1979-01-01

    The feasibility of using Brayton power systems for nuclear electric spacecraft was investigated. The primary performance parameters of systems mass and radiator area were determined for systems from 100 to 1000 kW sub e. Mathematical models of all system components were used to determine masses and volumes. Two completely independent systems provide propulsion power so that no single-point failure can jeopardize a mission. The waste heat radiators utilize armored heat pipes to limit meteorite puncture. The armor thickness was statistically determined to achieve the required probability of survival. A 400 kW sub e reference system received primary attention as required by the contract. The components of this system were defined and a conceptual layout was developed with encouraging results. An arrangement with redundant Brayton power systems having a 1500 K (2240 F) turbine inlet temperature was shown to be compatible with the dimensions of the space shuttle orbiter payload bay.

  14. Sensitivity Analysis of ProSEDS (Propulsive Small Expendable Deployer System) Data Communication System

    Science.gov (United States)

    Park, Nohpill; Reagan, Shawn; Franks, Greg; Jones, William G.

    1999-01-01

    This paper discusses analytical approaches to evaluating performance of Spacecraft On-Board Computing systems, thereby ultimately achieving a reliable spacecraft data communications systems. The sensitivity analysis approach of memory system on the ProSEDS (Propulsive Small Expendable Deployer System) as a part of its data communication system will be investigated. Also, general issues and possible approaches to reliable Spacecraft On-Board Interconnection Network and Processor Array will be shown. The performance issues of a spacecraft on-board computing systems such as sensitivity, throughput, delay and reliability will be introduced and discussed.

  15. Galileo spacecraft solid-state imaging system view of Antarctica

    Science.gov (United States)

    1990-01-01

    Galileo spacecraft solid-state imaging system view of Antarctica was taken during its first encounter with the Earth. This color picture of Antarctica is part of a mosaic of pictures covering the entire polar continent showing the Ross Ice Shelf and its border with the sea and mountains poking through the ice near the McMurdo Station. From top to bottom, the frame looks across about half of Antarctica. View provided by the Jet Propulsion Laboratory (JPL) with alternate number P-37297.

  16. A computer graphics system for visualizing spacecraft in orbit

    Science.gov (United States)

    Eyles, Don E.

    1989-01-01

    To carry out unanticipated operations with resources already in space is part of the rationale for a permanently manned space station in Earth orbit. The astronauts aboard a space station will require an on-board, spatial display tool to assist the planning and rehearsal of upcoming operations. Such a tool can also help astronauts to monitor and control such operations as they occur, especially in cases where first-hand visibility is not possible. A computer graphics visualization system designed for such an application and currently implemented as part of a ground-based simulation is described. The visualization system presents to the user the spatial information available in the spacecraft's computers by drawing a dynamic picture containing the planet Earth, the Sun, a star field, and up to two spacecraft. The point of view within the picture can be controlled by the user to obtain a number of specific visualization functions. The elements of the display, the methods used to control the display's point of view, and some of the ways in which the system can be used are described.

  17. Small systems – hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Bożek, Piotr, E-mail: piotr.bozek@fis.agh.edu.pl

    2016-12-15

    The scenario assuming a collective expansion stage in collisions of small systems, p-A, d-Au, and {sup 3}He-Au is discussed. A review of the observables predicted in relativistic hydrodynamic models in comparison with experimental data is presented, with arguments indicating the presence of collective expansion. The limits of applicability of the hydrodynamic model are addressed. We briefly indicate possible applications of the collective flow in small systems to study the space-time dynamics at very small scales in relativistic collisions.

  18. Electronic Systems for Spacecraft Vehicles: Required EDA Tools

    Science.gov (United States)

    Bachnak, Rafic

    1999-01-01

    The continuous increase in complexity of electronic systems is making the design and manufacturing of such systems more challenging than ever before. As a result, designers are finding it impossible to design efficient systems without the use of sophisticated Electronic Design Automation (EDA) tools. These tools offer integrated simulation of the electrical, mechanical, and manufacturing functions and lead to a correct by design methodology. This report identifies the EDA tools that would be needed to design, analyze, simulate, and evaluate electronic systems for spacecraft vehicles. In addition, the report presents recommendations to enhance the current JSC electronic design capabilities. This includes cost information and a discussion as to the impact, both positive and negative, of implementing the recommendations.

  19. Autonomous Navigation of the SSTI/Lewis Spacecraft Using the Global Positioning System (GPS)

    Science.gov (United States)

    Hart, R. C.; Long, A. C.; Lee, T.

    1997-01-01

    The National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD) is pursuing the application of Global Positioning System (GPS) technology to improve the accuracy and economy of spacecraft navigation. High-accuracy autonomous navigation algorithms are being flight qualified in conjunction with GSFC's GPS Attitude Determination Flyer (GADFLY) experiment on the Small Satellite Technology Initiative (SSTI) Lewis spacecraft, which is scheduled for launch in 1997. Preflight performance assessments indicate that these algorithms can provide a real-time total position accuracy of better than 10 meters (1 sigma) and velocity accuracy of better than 0.01 meter per second (1 sigma), with selective availability at typical levels. This accuracy is projected to improve to the 2-meter level if corrections to be provided by the GPS Wide Area Augmentation System (WAAS) are included.

  20. Definition of the topological structure of the automatic control system of spacecrafts

    International Nuclear Information System (INIS)

    KrasnoyarskiyRabochiy prospect, Krasnoyarsk, 660014 (Russian Federation))" data-affiliation=" (Siberian State Aerospace University named after Academician M.F.Reshetnev 31 KrasnoyarskiyRabochiy prospect, Krasnoyarsk, 660014 (Russian Federation))" >Zelenkov, P V; KrasnoyarskiyRabochiy prospect, Krasnoyarsk, 660014 (Russian Federation))" data-affiliation=" (Siberian State Aerospace University named after Academician M.F.Reshetnev 31 KrasnoyarskiyRabochiy prospect, Krasnoyarsk, 660014 (Russian Federation))" >Karaseva, M V; KrasnoyarskiyRabochiy prospect, Krasnoyarsk, 660014 (Russian Federation))" data-affiliation=" (Siberian State Aerospace University named after Academician M.F.Reshetnev 31 KrasnoyarskiyRabochiy prospect, Krasnoyarsk, 660014 (Russian Federation))" >Tsareva, E A; Tsarev, R Y

    2015-01-01

    The paper considers the problem of selection the topological structure of the automated control system of spacecrafts. The integer linear model of mathematical programming designed to define the optimal topological structure for spacecraft control is proposed. To solve the determination problem of topological structure of the control system of spacecrafts developed the procedure of the directed search of some structure variants according to the scheme 'Branch and bound'. The example of the automated control system of spacecraft development included the combination of ground control stations, managing the spacecraft of three classes with a geosynchronous orbit with constant orbital periods is presented

  1. Antimicrobial Materials for Advanced Microbial Control in Spacecraft Water Systems

    Science.gov (United States)

    Birmele, Michele; Caro, Janicce; Newsham, Gerard; Roberts, Michael; Morford, Megan; Wheeler, Ray

    2012-01-01

    Microbial detection, identification, and control are essential for the maintenance and preservation of spacecraft water systems. Requirements set by NASA put limitations on the energy, mass, materials, noise, cost, and crew time that can be devoted to microbial control. Efforts are being made to attain real-time detection and identification of microbial contamination in microgravity environments. Research for evaluating technologies for capability enhancement on-orbit is currently focused on the use of adenosine triphosphate (ATP) analysis for detection purposes and polymerase chain reaction (peR) for microbial identification. Additional research is being conducted on how to control for microbial contamination on a continual basis. Existing microbial control methods in spacecraft utilize iodine or ionic silver biocides, physical disinfection, and point-of-use sterilization filters. Although these methods are effective, they require re-dosing due to loss of efficacy, have low human toxicity thresholds, produce poor taste, and consume valuable mass and crew time. Thus, alternative methods for microbial control are needed. This project also explores ultraviolet light-emitting diodes (UV-LEDs), surface passivation methods for maintaining residual biocide levels, and several antimicrobial materials aimed at improving current microbial control techniques, as well as addressing other materials presently under analysis and future directions to be pursued.

  2. Reactor/Brayton power systems for nuclear electric spacecraft

    Science.gov (United States)

    Layton, J. P.

    1980-01-01

    Studies are currently underway to assess the technological feasibility of a nuclear-reactor-powered spacecraft propelled by electric thrusters. This vehicle would be capable of performing detailed exploration of the outer planets of the solar system during the remainder of this century. The purpose of this study was to provide comparative information on a closed cycle gas turbine power conversion system. The results have shown that the performance is very competitive and that a 400 kWe space power system is dimensionally compatible with a single Space Shuttle launch. Performance parameters of system mass and radiator area were determined for systems from 100 to 1000 kWe. A 400 kWe reference system received primary attention. The components of this system were defined and a conceptual layout was developed with encouraging results. The preliminary mass determination for the complete power system was very close to the desired goal of 20 kg/kWe. Use of more advanced technology (higher turbine inlet temperature) will substantially improve system performance characteristics.

  3. Intelligent Data Visualization for Cross-Checking Spacecraft System Diagnosis

    Science.gov (United States)

    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.

  4. An expert system for diagnosing environmentally induced spacecraft anomalies

    Science.gov (United States)

    Rolincik, Mark; Lauriente, Michael; Koons, Harry C.; Gorney, David

    1992-01-01

    A new rule-based, machine independent analytical tool was designed for diagnosing spacecraft anomalies using an expert system. Expert systems provide an effective method for saving knowledge, allow computers to sift through large amounts of data pinpointing significant parts, and most importantly, use heuristics in addition to algorithms, which allow approximate reasoning and inference and the ability to attack problems not rigidly defined. The knowledge base consists of over two-hundred (200) rules and provides links to historical and environmental databases. The environmental causes considered are bulk charging, single event upsets (SEU), surface charging, and total radiation dose. The system's driver translates forward chaining rules into a backward chaining sequence, prompting the user for information pertinent to the causes considered. The use of heuristics frees the user from searching through large amounts of irrelevant information and allows the user to input partial information (varying degrees of confidence in an answer) or 'unknown' to any question. The modularity of the expert system allows for easy updates and modifications. It not only provides scientists with needed risk analysis and confidence not found in algorithmic programs, but is also an effective learning tool, and the window implementation makes it very easy to use. The system currently runs on a Micro VAX II at Goddard Space Flight Center (GSFC). The inference engine used is NASA's C Language Integrated Production System (CLIPS).

  5. Small Wind Energy Systems

    DEFF Research Database (Denmark)

    Simões, Marcelo Godoy; Farret, Felix Alberto; Blaabjerg, Frede

    2017-01-01

    considered when selecting a generator for a wind power plant, including capacity of the AC system, types of loads, availability of spare parts, voltage regulation, technical personal and cost. If several loads are likely inductive, such asphase-controlled converters, motors and fluorescent lights......This chapter intends to serve as a brief guide when someone is considering the use of wind energy for small power applications. It is discussed that small wind energy systems act as the major energy source for residential or commercial applications, or how to make it part of a microgrid...... as a distributed generator. In this way, sources and loads are connected in such a way to behave as a renewable dispatch center. With this regard, non-critical loads might be curtailed or shed during times of energy shortfall or periods of high costs of energy production. If such a wind energy system is connected...

  6. Spacecraft contamination programs within the Air Force Systems Command Laboratories

    Science.gov (United States)

    Murad, Edmond

    1990-01-01

    Spacecraft contamination programs exist in five independent AFSC organizations: Geophysics Laboratory (GL), Arnold Engineering and Development Center (AEDC), Rome Air Development Center (RADC/OSCE), Wright Research and Development Center (MLBT), Armament Laboratory (ATL/SAI), and Space Systems Division (SSD/OL-AW). In addition, a sizable program exists at Aerospace Corp. These programs are complementary, each effort addressing a specific area of expertise: GL's effort is aimed at addressing the effects of on-orbit contamination; AEDC's effort is aimed at ground simulation and measurement of optical contamination; RADC's effort addresses the accumulation, measurement, and removal of contamination on large optics; MLBT's effort is aimed at understanding the effect of contamination on materials; ATL's effort is aimed at understanding the effect of plume contamination on systems; SSD's effort is confined to the integration of some contamination experiments sponsored by SSD/CLT; and Aerospace Corp.'s effort is aimed at supporting the needs of the using System Program Offices (SPO) in specific areas, such as contamination during ground handling, ascent phase, laboratory measurements aimed at understanding on-orbit contamination, and mass loss and mass gain in on-orbit operations. These programs are described in some detail, with emphasis on GL's program.

  7. Error Analysis System for Spacecraft Navigation Using the Global Positioning System (GPS)

    Science.gov (United States)

    Truong, S. H.; Hart, R. C.; Hartman, K. R.; Tomcsik, T. L.; Searl, J. E.; Bernstein, A.

    1997-01-01

    The Flight Dynamics Division (FDD) at the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) is currently developing improved space-navigation filtering algorithms to use the Global Positioning System (GPS) for autonomous real-time onboard orbit determination. In connection with a GPS technology demonstration on the Small Satellite Technology Initiative (SSTI)/Lewis spacecraft, FDD analysts and programmers have teamed with the GSFC Guidance, Navigation, and Control Branch to develop the GPS Enhanced Orbit Determination Experiment (GEODE) system. The GEODE system consists of a Kalman filter operating as a navigation tool for estimating the position, velocity, and additional states required to accurately navigate the orbiting Lewis spacecraft by using astrodynamic modeling and GPS measurements from the receiver. A parallel effort at the FDD is the development of a GPS Error Analysis System (GEAS) that will be used to analyze and improve navigation filtering algorithms during development phases and during in-flight calibration. For GEAS, the Kalman filter theory is extended to estimate the errors in position, velocity, and other error states of interest. The estimation of errors in physical variables at regular intervals will allow the time, cause, and effect of navigation system weaknesses to be identified. In addition, by modeling a sufficient set of navigation system errors, a system failure that causes an observed error anomaly can be traced and accounted for. The GEAS software is formulated using Object Oriented Design (OOD) techniques implemented in the C++ programming language on a Sun SPARC workstation. The Phase 1 of this effort is the development of a basic system to be used to evaluate navigation algorithms implemented in the GEODE system. This paper presents the GEAS mathematical methodology, systems and operations concepts, and software design and implementation. Results from the use of the basic system to evaluate

  8. Hummingbird - A Very Low Cost, High Delta V Spacecraft for Solar System Exploration, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Based on Microcosm's development of a high delta-V small Earth observation spacecraft called NanoEye, with a planned recurring cost of $2 million, Microcosm will...

  9. Multi-spacecraft observations of small-scale fluctuations in density and fields in plasmaspheric plumes

    Directory of Open Access Journals (Sweden)

    H. Matsui

    2012-03-01

    Full Text Available In this event study, small-scale fluctuations in plasmaspheric plumes with time scales of ~10 s to minutes in the spacecraft frame are examined. In one event, plasmaspheric plumes are observed by Cluster, while IMAGE measured density enhancement at a similar location. Fluctuations in density exist in plumes as detected by Cluster and are accompanied by fluctuations in magnetic fields and electric fields. Magnetic fluctuations are transverse and along the direction of the plumes. The E/B ratio is smaller than the Alfvén velocity. Another similar event is briefly presented. We then consider physical properties of the fluctuations. Alfvén mode modulated by the feedback instability is one possibility, although non-local generation is likely. It is hard to show that the fluctuations represent a fast mode. Interchange motion is possible due to the consistency between measurements and expectations. The energy source could be a pressure or density gradient in plasmaspheric plumes. When more events are accumulated so that statistical analysis becomes feasible, this type of study will be useful to understand the time evolution of plumes.

  10. Small Wind Energy Systems

    DEFF Research Database (Denmark)

    Simoes, Marcelo; Farret, Felix Alberto; Blaabjerg, Frede

    2015-01-01

    devices, and a centralized distribution control. In order to establish a small wind energy system it is important to observe the following: (i) Attending the energy requirements of the actual or future consumers; (ii) Establishing civil liabilities in case of accidents and financial losses due to shortage...... or low quality of energy; (iii) Negotiating collective conditions to interconnect the microgrid with the public network or with other sources of energy that is independent of wind resources; (iv) Establishing a performance criteria of power quality and reliability to end-users, in order to reduce costs...... and guaranteeing an acceptable energy supply. This paper discuss how performance is affected by local conditions and random nature of the wind, power demand profiles, turbine related factors, and presents the technical issues for implementing a self-excited induction generator system, or a permanent magnet based...

  11. The Case for Small Spacecraft: An Integrated Perspective on Electric Propulsion

    Science.gov (United States)

    1995-01-01

    microsatellite classes (termed small saellites for the remaining por-tion of this paper). A -large body -of information has been generated over the past...there is a growing market for small satellite propulsion. This year several flight es:eriments and commercial systems will deploy with electtric ...determined from equation 7. Cd is the drag coefficient, which is generally on the order of one[ 2], and we will assume to be 2.2. Although it neglects lateral

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  14. Equations of Motion of Free-Floating Spacecraft-Manipulator Systems: An Engineer's Tutorial

    Directory of Open Access Journals (Sweden)

    Markus Wilde

    2018-04-01

    Full Text Available The paper provides a step-by-step tutorial on the Generalized Jacobian Matrix (GJM approach for modeling and simulation of spacecraft-manipulator systems. The General Jacobian Matrix approach describes the motion of the end-effector of an underactuated manipulator system solely by the manipulator joint rotations, with the attitude and position of the base-spacecraft resulting from the manipulator motion. The coupling of the manipulator motion with the base-spacecraft are thus expressed in a generalized inertia matrix and a GJM. The focus of the paper lies on the complete analytic derivation of the generalized equations of motion of a free-floating spacecraft-manipulator system. This includes symbolic analytic expressions for all inertia property matrices of the system, including their time derivatives and joint-angle derivatives, as well as an expression for the generalized Jacobian of a generic point on any link of the spacecraft-manipulator system. The kinematics structure of the spacecraft-manipulator system is described both in terms of direction-cosine matrices and unit quaternions. An additional important contribution of this paper is to propose a new and more detailed definition for the modes of maneuvering of a spacecraft-manipulator. In particular, the two commonly used categories free-flying and free-floating are expanded by the introduction of five categories, namely floating, rotation-floating, rotation-flying, translation-flying, and flying. A fully-symbolic and a partially-symbolic option for the implementation of a numerical simulation model based on the proposed analytic approach are introduced and exemplary simulation results for a planar four-link spacecraft-manipulator system and a spatial six-link spacecraft manipulator system are presented.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  17. Compact Chemical Monitor for Silver Ions in Spacecraft Water Systems, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA has identified silver ions as the best candidate biocide for use in the potable water system on next-generation spacecraft. Though significant work has been...

  18. A Hybrid Systems Strategy to Support Autonomous Spacecraft Trajectory Design and Optimization in Multiple Dynamical Regimes

    Data.gov (United States)

    National Aeronautics and Space Administration — With ever increasing numbers of near-Earth satellites and deep space missions, autonomous spacecraft guidance, navigation, and control (GNC) systems are increasingly...

  19. Global Precipitation Measurement (GPM) Mission Core Spacecraft Systems Engineering Challenges

    Science.gov (United States)

    Bundas, David J.; ONeill, Deborah; Field, Thomas; Meadows, Gary; Patterson, Peter

    2006-01-01

    The Global Precipitation Measurement (GPM) Mission is a collaboration between the National Aeronautics and Space Administration (NASA) and the Japanese Aerospace Exploration Agency (JAXA), and other US and international partners, with the goal of monitoring the diurnal and seasonal variations in precipitation over the surface of the earth. These measurements will be used to improve current climate models and weather forecasting, and enable improved storm and flood warnings. This paper gives an overview of the mission architecture and addresses the status of some key trade studies, including the geolocation budgeting, design considerations for spacecraft charging, and design issues related to the mitigation of orbital debris.

  20. Assessment of the Use of Nanofluids in Spacecraft Active Thermal Control Systems

    Science.gov (United States)

    Ungar, Eugene K.; Erickson, Lisa R.

    2011-01-01

    The addition of metallic nanoparticles to a base heat transfer fluid can dramatically increase its thermal conductivity. These nanofluids have been shown to have advantages in some heat transport systems. Their enhanced properties can allow lower system volumetric flow rates and can reduce the required pumping power. Nanofluids have been suggested for use as working fluids for spacecraft Active Thermal Control Systems (ATCSs). However, there are no studies showing the end-to-end effect of nanofluids on the design and performance of spacecraft ATCSs. In the present work, a parametric study is performed to assess the use of nanofluids in a spacecraft ATCSs. The design parameters of the current Orion capsule and the tabulated thermophysical properties of nanofluids are used to assess the possible benefits of nanofluids and how their incorporation affects the overall design of a spacecraft ATCS. The study shows that the unique system and component-level design parameters of spacecraft ATCSs render them best suited for pure working fluids. The addition of nanoparticles to typical spacecraft thermal control working fluids actually results in an increase in the system mass and required pumping power.

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

    Science.gov (United States)

    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.

  2. Spacecraft Attitude Determination

    DEFF Research Database (Denmark)

    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...

  3. Small supermarket management system

    Institute of Scientific and Technical Information of China (English)

    曹正

    2016-01-01

    This system USES the Java language in the MyEclipse platform development tool, SQL2005 as the database platform for data and data, the SQL2005 required for the user operating system. It mainly implements the daily management of goods, including purchase management, inventory management, sales management, personnel management and supplier management. The system can also complete the functions of browsing, querying, adding, deleting and modifying relevant information. This topic is the core of the stock management, inventory management and sales management, at the same time, the system also has the full user management and permissions management function..

  4. A Small Spacecraft Swarm Deployment and Stationkeeping Strategy for Sun-Earth L1 Halo Orbits

    Science.gov (United States)

    Renea Conn, Tracie; Bookbinder, Jay

    2018-01-01

    Spacecraft orbits about the Sun-Earth librarian point L1 have been of interest since the 1950s. An L1 halo orbit was first achieved with the International Sun-Earth Explorer-3 (ISEE-3) mission, and similar orbits around Sun-Earth L1 were achieved in the Solar and Heliospheric Observatory (SOHO), Advanced Composition Explorer (ACE), Genesis, and Deep Space Climate Observatory (DSCOVR) missions. With recent advancements in CubeSat technology, we envision that it will soon be feasible to deploy CubeSats at L1. As opposed to these prior missions where one large satellite orbited alone, a swarm of CubeSats at L1 would enable novel science data return, providing a topology for intersatellite measurements of heliophysics phenomena both spatially and temporally, at varying spatial scales.The purpose of this iPoster is to present a flight dynamics strategy for a swarm of numerous CubeSats orbiting Sun-Earth L1. The presented method is a coupled, two-part solution. First, we present a deployment strategy for the CubeSats that is optimized to produce prescribed, time-varying intersatellite baselines for the purposes of collecting magnetometer data as well as radiometric measurements from cross-links. Second, we employ a loose control strategy that was successfully applied to SOHO and ACE for minimized stationkeeping propellant expenditure. We emphasize that the presented solution is practical within the current state-of-the-art and heritage CubeSat technology, citing capabilities of CubeSat designs that will launch on the upcoming Exploration Mission 1 (EM-1) to lunar orbits and beyond. Within this iPoster, we present animations of the simulated deployment strategy and resulting spacecraft trajectories. Mission design parameters such as total Δv required for long-term station keeping and minimum/maximum/mean spacecraft separation distances are also presented.

  5. Rapid Onboard Trajectory Design for Autonomous Spacecraft in Multibody Systems

    Science.gov (United States)

    Trumbauer, Eric Michael

    This research develops automated, on-board trajectory planning algorithms in order to support current and new mission concepts. These include orbiter missions to Phobos or Deimos, Outer Planet Moon orbiters, and robotic and crewed missions to small bodies. The challenges stem from the limited on-board computing resources which restrict full trajectory optimization with guaranteed convergence in complex dynamical environments. The approach taken consists of leveraging pre-mission computations to create a large database of pre-computed orbits and arcs. Such a database is used to generate a discrete representation of the dynamics in the form of a directed graph, which acts to index these arcs. This allows the use of graph search algorithms on-board in order to provide good approximate solutions to the path planning problem. Coupled with robust differential correction and optimization techniques, this enables the determination of an efficient path between any boundary conditions with very little time and computing effort. Furthermore, the optimization methods developed here based on sequential convex programming are shown to have provable convergence properties, as well as generating feasible major iterates in case of a system interrupt -- a key requirement for on-board application. The outcome of this project is thus the development of an algorithmic framework which allows the deployment of this approach in a variety of specific mission contexts. Test cases related to missions of interest to NASA and JPL such as a Phobos orbiter and a Near Earth Asteroid interceptor are demonstrated, including the results of an implementation on the RAD750 flight processor. This method fills a gap in the toolbox being developed to create fully autonomous space exploration systems.

  6. Small space reactor power systems for unmanned solar system exploration missions

    International Nuclear Information System (INIS)

    Bloomfield, H.S.

    1987-12-01

    A preliminary feasibility study of the application of small nuclear reactor space power systems to the Mariner Mark II Cassini spacecraft/mission was conducted. The purpose of the study was to identify and assess the technology and performance issues associated with the reactor power system/spacecraft/mission integration. The Cassini mission was selected because study of the Saturn system was identified as a high priority outer planet exploration objective. Reactor power systems applied to this mission were evaluated for two different uses. First, a very small 1 kWe reactor power system was used as an RTG replacement for the nominal spacecraft mission science payload power requirements while still retaining the spacecraft's usual bipropellant chemical propulsion system. The second use of reactor power involved the additional replacement of the chemical propulsion system with a small reactor power system and an electric propulsion system. The study also provides an examination of potential applications for the additional power available for scientific data collection. The reactor power system characteristics utilized in the study were based on a parametric mass model that was developed specifically for these low power applications. The model was generated following a neutronic safety and operational feasibility assessment of six small reactor concepts solicited from U.S. industry. This assessment provided the validation of reactor safety for all mission phases and generatad the reactor mass and dimensional data needed for the system mass model

  7. Lifetime of a spacecraft around a synchronous system of asteroids using a dipole model

    Science.gov (United States)

    dos Santos, Leonardo Barbosa Torres; de Almeida Prado, Antonio F. Bertachini; Sanchez, Diogo Merguizo

    2017-11-01

    Space missions allow us to expand our knowledge about the origin of the solar system. It is believed that asteroids and comets preserve the physical characteristics from the time that the solar system was created. For this reason, there was an increase of missions to asteroids in the past few years. To send spacecraft to asteroids or comets is challenging, since these objects have their own characteristics in several aspects, such as size, shape, physical properties, etc., which are often only discovered after the approach and even after the landing of the spacecraft. These missions must be developed with sufficient flexibility to adjust to these parameters, which are better determined only when the spacecraft reaches the system. Therefore, conducting a dynamic investigation of a spacecraft around a multiple asteroid system offers an extremely rich environment. Extracting accurate information through analytical approaches is quite challenging and requires a significant number of restrictive assumptions. For this reason, a numerical approach to the dynamics of a spacecraft in the vicinity of a binary asteroid system is offered in this paper. In the present work, the equations of the Restricted Synchronous Four-Body Problem (RSFBP) are used to model a binary asteroid system. The main objective of this work is to construct grids of initial conditions, which relates semi-major axis and eccentricity, in order to quantify the lifetime of a spacecraft when released close to the less massive body of the binary system (modeled as a rotating mass dipole). We performed an analysis of the lifetime of the spacecraft considering several mass ratios of a binary system of asteroids and investigating the behavior of a spacecraft in the vicinity of this system. We analyze direct and retrograde orbits. This study investigated orbits that survive for at least 500 orbital periods of the system (which is approximately one year), then not colliding or escaping from the system during this

  8. Miniature Heat Transport System for Spacecraft Thermal Control

    Science.gov (United States)

    Ochterbeck, Jay M.; Ku, Jentung (Technical Monitor)

    2002-01-01

    Loop heat pipes (LHP) are efficient devices for heat transfer and use the basic principle of a closed evaporation-condensation cycle. The advantage of using a loop heat pipe over other conventional methods is that large quantities of heat can be transported through a small cross-sectional area over a considerable distance with no additional power input to the system. By using LHPs, it seems possible to meet the growing demand for high-power cooling devices. Although they are somewhat similar to conventional heat pipes, LHPs have a whole set of unique properties, such as low pressure drops and flexible lines between condenser and evaporator, that make them rather promising. LHPs are capable of providing a means of transporting heat over long distances with no input power other than the heat being transported because of the specially designed evaporator and the separation of liquid and vapor lines. For LHP design and fabrication, preliminary analysis on the basis of dimensionless criteria is necessary because of certain complicated phenomena that take place in the heat pipe. Modeling the performance of the LHP and miniaturizing its size are tasks and objectives of current research. In the course of h s work, the LHP and its components, including the evaporator (the most critical and complex part of the LHP), were modeled with the corresponding dimensionless groups also being investigated. Next, analysis of heat and mass transfer processes in the LHP, selection of the most weighted criteria from known dimensionless groups (thermal-fluid sciences), heat transfer rate limits, (heat pipe theory), and experimental ratios which are unique to a given heat pipe class are discussed. In the third part of the report, two-phase flow heat and mass transfer performances inside the LHP condenser are analyzed and calculated for Earth-normal gravity and microgravity conditions. On the basis of recent models and experimental databanks, an analysis for condensing two-phase flow regimes

  9. Power quality load management for large spacecraft electrical power systems

    Science.gov (United States)

    Lollar, Louis F.

    1988-01-01

    In December, 1986, a Center Director's Discretionary Fund (CDDF) proposal was granted to study power system control techniques in large space electrical power systems. Presented are the accomplishments in the area of power system control by power quality load management. In addition, information concerning the distortion problems in a 20 kHz ac power system is presented.

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

    Science.gov (United States)

    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.

  11. Spacecraft Electrical Power System (EPS) generic analysis tools and techniques

    Science.gov (United States)

    Morris, Gladys M.; Sheppard, Mark A.

    1992-01-01

    An overview is provided of the analysis tools and techiques used in modeling the Space Station Freedom electrical power system, as well as future space vehicle power systems. The analysis capabilities of the Electrical Power System (EPS) are described and the EPS analysis tools are surveyed.

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

    Science.gov (United States)

    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.

  13. Design issues of the piezo motor for the spacecraft reflector control system

    Directory of Open Access Journals (Sweden)

    Azin Anton

    2018-01-01

    Full Text Available Creation of large-size reflectors for spacecrafts is a topical issue for the space industry. The accuracy of the reflecting surface form and the structure weight are the main criteria for the reflector design. The accuracy of the reflecting surface form during a long-term operation is provided by adjustment when using piezoelectric motors in the reflector design. These motors have small weight-size parameters and can reach great torque values. The piezo motor is a distributed mechanical-acoustic oscillation system. Mechanical-acoustic oscillations are generated in the piezo motor by a PZT-stack and transmitted to an oscillator element, and then from the oscillator element to a load action element. At high frequencies, when dimensions of the oscillator are proportionate to the wavelength, the energy is transmitted by means of acoustic waves. In this case, mechanical waves practically are not involved in the energy transmission process. This thesis shows a method for selecting the material of a mechanical-acoustic oscillation system according to the efficiency of the acoustic energy transmission via a piezoelectric layered structure.

  14. The Evolution of Software and Its Impact on Complex System Design in Robotic Spacecraft Embedded Systems

    Science.gov (United States)

    Butler, Roy

    2013-01-01

    The growth in computer hardware performance, coupled with reduced energy requirements, has led to a rapid expansion of the resources available to software systems, driving them towards greater logical abstraction, flexibility, and complexity. This shift in focus from compacting functionality into a limited field towards developing layered, multi-state architectures in a grand field has both driven and been driven by the history of embedded processor design in the robotic spacecraft industry.The combinatorial growth of interprocess conditions is accompanied by benefits (concurrent development, situational autonomy, and evolution of goals) and drawbacks (late integration, non-deterministic interactions, and multifaceted anomalies) in achieving mission success, as illustrated by the case of the Mars Reconnaissance Orbiter. Approaches to optimizing the benefits while mitigating the drawbacks have taken the form of the formalization of requirements, modular design practices, extensive system simulation, and spacecraft data trend analysis. The growth of hardware capability and software complexity can be expected to continue, with future directions including stackable commodity subsystems, computer-generated algorithms, runtime reconfigurable processors, and greater autonomy.

  15. Real-Time Analytics Test System for Distributed Spacecraft Missions

    Data.gov (United States)

    National Aeronautics and Space Administration — Upcoming DSM missions will produce unprecedented amounts of data during both I&T and flight, overwhelming current command/telemetry systems. The amount of data,...

  16. A Compact, Low Power Pulsed Optical Communication System for Spacecraft

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this project is to reduce the power required for high bandwidth, deep space laser communications systems. Our concept will encode data in the time delay...

  17. System concepts and design examples for optical communication with planetary spacecraft

    Science.gov (United States)

    Lesh, James R.

    Systems concepts for optical communication with future deep-space (planetary) spacecraft are described. These include not only the optical transceiver package aboard the distant spacecraft, but the earth-vicinity optical-communications receiving station as well. Both ground-based, and earth-orbiting receivers are considered. Design examples for a number of proposed or potential deep-space missions are then presented. These include an orbital mission to Saturn, a Lander and Rover mission to Mars, and an astronomical mission to a distance of 1000 astronomical units.

  18. Analysis on coverage ability of BeiDou navigation satellite system for manned spacecraft

    Science.gov (United States)

    Zhao, Sihao; Yao, Zheng; Zhuang, Xuebin; Lu, Mingquan

    2014-12-01

    To investigate the service ability of the BeiDou Navigation Satellite System (BDS) for manned spacecraft, both the current regional and the future-planned global constellations of BDS are introduced and simulated. The orbital parameters of the International Space Station and China's Tiangong-1 spacelab are used to create the simulation scenario and evaluate the performance of the BDS constellations. The number of visible satellites and the position dilution (PDOP) of precision at the spacecraft-based receiver are evaluated. Simulation and analysis show quantitative results on the coverage ability and time percentages of both the current BDS regional and future global constellations for manned-space orbits which can be a guideline to the applications and mission design of BDS receivers on manned spacecraft.

  19. Link Analysis of High Throughput Spacecraft Communication Systems for Future Science Missions

    Science.gov (United States)

    Simons, Rainee N.

    2015-01-01

    NASA's plan to launch several spacecrafts into low Earth Orbit (LEO) to support science missions in the next ten years and beyond requires down link throughput on the order of several terabits per day. The ability to handle such a large volume of data far exceeds the capabilities of current systems. This paper proposes two solutions, first, a high data rate link between the LEO spacecraft and ground via relay satellites in geostationary orbit (GEO). Second, a high data rate direct to ground link from LEO. Next, the paper presents results from computer simulations carried out for both types of links taking into consideration spacecraft transmitter frequency, EIRP, and waveform; elevation angle dependent path loss through Earths atmosphere, and ground station receiver GT.

  20. Centralized database for interconnection system design. [for spacecraft

    Science.gov (United States)

    Billitti, Joseph W.

    1989-01-01

    A database application called DFACS (Database, Forms and Applications for Cabling and Systems) is described. The objective of DFACS is to improve the speed and accuracy of interconnection system information flow during the design and fabrication stages of a project, while simultaneously supporting both the horizontal (end-to-end wiring) and the vertical (wiring by connector) design stratagems used by the Jet Propulsion Laboratory (JPL) project engineering community. The DFACS architecture is centered around a centralized database and program methodology which emulates the manual design process hitherto used at JPL. DFACS has been tested and successfully applied to existing JPL hardware tasks with a resulting reduction in schedule time and costs.

  1. Design of RTPV generators integrated with new millennium spacecraft for outer solar system

    International Nuclear Information System (INIS)

    Schock, A.; Or, C.; Kumar, V.

    1996-01-01

    The National Aeronautics and Space Administration's recently inaugurated New Millennium program, with its emphasis on miniaturized spacecraft, has generated interest in a low-power (10- to 30-watt), low-mass, high-efficiency RTPV (Radioisotope Thermophotovoltaic) power system. This led to a Department of Energy (DOE)-sponsored design study of such a system. A 75-watt design employed two 250-watt General Purpose Heat Source (GPHS) modules that DOE had previously developed and safety-qualified for various space missions. These modules were too large for the small RTPVs described in this paper. To minimize the need for new development and safety verification studies, derivative designs for 125-watt and 62.5-watt heat source modules containing identical fuel pellets, clads, impact shell, and thermal insulation were generated along with a novel heat source support scheme to reduce the heat losses through the structural supports, and a new and much simpler radiator structure, employing no honeycombs or heat pipes. Previous RTPV study had been based on the use of GaSb PV cells and spectrally selective IR filters. Because of the very encouraging results of system design studies, in the fall of 1994 an experimental program was initiated to develop improved filters and cells, to demonstrate how much improvement can actually be achieved. First priority was given to filter improvements, because our system studies indicated that improved filters would have a much greater effect on system performance than cell improvements. By September 1995 about 94% of the filter performance improvement projected in 1993 had been achieved. (Abstract Truncated)

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

    Science.gov (United States)

    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.

  3. Disinfection of Spacecraft Potable Water Systems by Passivation with Ionic Silver

    Science.gov (United States)

    Birmele, Michele N.; McCoy, LaShelle e.; Roberts, Michael S.

    2011-01-01

    Microbial growth is common on wetted surfaces in spacecraft environmental control and life support systems despite the use of chemical and physical disinfection methods. Advanced control technologies are needed to limit microorganisms and increase the reliability of life support systems required for long-duration human missions. Silver ions and compounds are widely used as antimicrobial agents for medical applications and continue to be used as a residual biocide in some spacecraft water systems. The National Aeronautics and Space Administration (NASA) has identified silver fluoride for use in the potable water system on the next generation spacecraft. Due to ionic interactions between silver fluoride in solution and wetted metallic surfaces, ionic silver is rapidly depleted from solution and loses its antimicrobial efficacy over time. This report describes research to prolong the antimicrobial efficacy of ionic silver by maintaining its solubility. Three types of metal coupons (lnconel 718, Stainless Steel 316, and Titanium 6AI-4V) used in spacecraft potable water systems were exposed to either a continuous flow of water amended with 0.4 mg/L ionic silver fluoride or to a static, pre-treatment passivation in 50 mg/L ionic silver fluoride with or without a surface oxidation pre-treatment. Coupons were then challenged in a high-shear, CDC bioreactor (BioSurface Technologies) by exposure to six bacteria previously isolated from spacecraft potable water systems. Continuous exposure to 0.4 mg/L ionic silver over the course of 24 hours during the flow phase resulted in a >7-log reduction. The residual effect of a 24-hour passivation treatment in 50 mg/L of ionic silver resulted in a >3-log reduction, whereas a two-week treatment resulted in a >4-log reduction. Results indicate that 0.4 mg/L ionic silver is an effective biocide against many bacteria and that a prepassivation of metal surfaces with silver can provide additional microbial control.

  4. Small systems at the LHC

    Science.gov (United States)

    Preghenella, Roberto

    2018-02-01

    In these proceedings, I report on a selection of recent LHC results in small systems from ALICE [1], ATLAS [2] and CMS [3] experiments. Due to the fact that the investigation of QCD in small systems at high multiplicity is becoming an increasingly large subject, interesting the heavy-ion community and more in general the high-energy physics community, not all the related topics can be discussed in this paper. The focus will be given to some of the measurements addressing the physics of collective phenomena in small systems and to the recent results on strangeness enhancement in proton-proton collisions. The reader must be informed that a large number of interesting results did not find space in the discussion reported here.

  5. Solar Power System Options for the Radiation and Technology Demonstration Spacecraft

    Science.gov (United States)

    Kerslake, Thomas W.; Haraburda, Francis M.; Riehl, John P.

    2000-01-01

    The Radiation and Technology Demonstration (RTD) Mission has the primary objective of demonstrating high-power (10 kilowatts) electric thruster technologies in Earth orbit. This paper discusses the conceptual design of the RTD spacecraft photovoltaic (PV) power system and mission performance analyses. These power system studies assessed multiple options for PV arrays, battery technologies and bus voltage levels. To quantify performance attributes of these power system options, a dedicated Fortran code was developed to predict power system performance and estimate system mass. The low-thrust mission trajectory was analyzed and important Earth orbital environments were modeled. Baseline power system design options are recommended on the basis of performance, mass and risk/complexity. Important findings from parametric studies are discussed and the resulting impacts to the spacecraft design and cost.

  6. Dissertation Defense Computational Fluid Dynamics Uncertainty Analysis for Payload Fairing Spacecraft Environmental Control Systems

    Science.gov (United States)

    Groves, Curtis Edward

    2014-01-01

    Spacecraft thermal protection systems are at risk of being damaged due to airflow produced from Environmental Control Systems. There are inherent uncertainties and errors associated with using Computational Fluid Dynamics to predict the airflow field around a spacecraft from the Environmental Control System. This paper describes an approach to quantify the uncertainty in using Computational Fluid Dynamics to predict airflow speeds around an encapsulated spacecraft without the use of test data. Quantifying the uncertainty in analytical predictions is imperative to the success of any simulation-based product. The method could provide an alternative to traditional "validation by test only" mentality. This method could be extended to other disciplines and has potential to provide uncertainty for any numerical simulation, thus lowering the cost of performing these verifications while increasing the confidence in those predictions. Spacecraft requirements can include a maximum airflow speed to protect delicate instruments during ground processing. Computational Fluid Dynamics can be used to verify these requirements; however, the model must be validated by test data. This research includes the following three objectives and methods. Objective one is develop, model, and perform a Computational Fluid Dynamics analysis of three (3) generic, non-proprietary, environmental control systems and spacecraft configurations. Several commercially available and open source solvers have the capability to model the turbulent, highly three-dimensional, incompressible flow regime. The proposed method uses FLUENT, STARCCM+, and OPENFOAM. Objective two is to perform an uncertainty analysis of the Computational Fluid Dynamics model using the methodology found in "Comprehensive Approach to Verification and Validation of Computational Fluid Dynamics Simulations". This method requires three separate grids and solutions, which quantify the error bars around Computational Fluid Dynamics

  7. Dissertation Defense: Computational Fluid Dynamics Uncertainty Analysis for Payload Fairing Spacecraft Environmental Control Systems

    Science.gov (United States)

    Groves, Curtis Edward

    2014-01-01

    Spacecraft thermal protection systems are at risk of being damaged due to airflow produced from Environmental Control Systems. There are inherent uncertainties and errors associated with using Computational Fluid Dynamics to predict the airflow field around a spacecraft from the Environmental Control System. This paper describes an approach to quantify the uncertainty in using Computational Fluid Dynamics to predict airflow speeds around an encapsulated spacecraft without the use of test data. Quantifying the uncertainty in analytical predictions is imperative to the success of any simulation-based product. The method could provide an alternative to traditional validation by test only mentality. This method could be extended to other disciplines and has potential to provide uncertainty for any numerical simulation, thus lowering the cost of performing these verifications while increasing the confidence in those predictions.Spacecraft requirements can include a maximum airflow speed to protect delicate instruments during ground processing. Computational Fluid Dynamics can be used to verify these requirements; however, the model must be validated by test data. This research includes the following three objectives and methods. Objective one is develop, model, and perform a Computational Fluid Dynamics analysis of three (3) generic, non-proprietary, environmental control systems and spacecraft configurations. Several commercially available and open source solvers have the capability to model the turbulent, highly three-dimensional, incompressible flow regime. The proposed method uses FLUENT, STARCCM+, and OPENFOAM. Objective two is to perform an uncertainty analysis of the Computational Fluid Dynamics model using the methodology found in Comprehensive Approach to Verification and Validation of Computational Fluid Dynamics Simulations. This method requires three separate grids and solutions, which quantify the error bars around Computational Fluid Dynamics predictions

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

    Science.gov (United States)

    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.

  9. The Global Precipitation Measurement (GPM) Spacecraft Power System Design and Orbital Performance

    Science.gov (United States)

    Dakermanji, George; Burns, Michael; Lee, Leonine; Lyons, John; Kim, David; Spitzer, Thomas; Kercheval, Bradford

    2016-01-01

    The Global Precipitation Measurement (GPM) spacecraft was jointly developed by National Aeronautics and Space Administration (NASA) and Japan Aerospace Exploration Agency (JAXA). It is a Low Earth Orbit (LEO) spacecraft launched on February 27, 2014. The spacecraft is in a circular 400 Km altitude, 65 degrees inclination nadir pointing orbit with a three year basic mission life. The solar array consists of two sun tracking wings with cable wraps. The panels are populated with triple junction cells of nominal 29.5% efficiency. One axis is canted by 52 degrees to provide power to the spacecraft at high beta angles. The power system is a Direct Energy Transfer (DET) system designed to support 1950 Watts orbit average power. The batteries use SONY 18650HC cells and consist of three 8s x 84p batteries operated in parallel as a single battery. The paper describes the power system design details, its performance to date and the lithium ion battery model that was developed for use in the energy balance analysis and is being used to predict the on-orbit health of the battery.

  10. Analysis of the Apollo spacecraft operational data management system. Executive summary

    Science.gov (United States)

    1971-01-01

    A study was made of Apollo, Skylab, and several other data management systems to determine those techniques which could be applied to the management of operational data for future manned spacecraft programs. The results of the study are presented and include: (1) an analysis of present data management systems, (2) a list of requirements for future operational data management systems, (3) an evaluation of automated data management techniques, and (4) a plan for data management applicable to future space programs.

  11. Integrated water and waste management system for future spacecraft

    Science.gov (United States)

    Ingelfinger, A. L.; Murray, R. W.

    1974-01-01

    Over 200 days of continuous testing have been completed on an integrated waste management-water recovery system developed by General Electric under a jointly funded AEC/NASA/AF Contract. The 4 man system provides urine, feces, and trash collection; water reclamation; storage, heating and dispensing of the water; storage and disposal of the feces and urine residue and all of other nonmetallic waste material by incineration. The heat required for the 1200 deg F purification processes is provided by a single 420-w radioisotope heater. A second 836-w radioisotope heater supplemented by 720 w of electrical heat provides for distillation and water heating. Significant test results are no pre-or-post treatment, greater than 98 per cent potable water recovery, approximately 95 per cent reduction in solids weight and volume, all outflows are sterile with the water having no bacteria or virus, and the radioisotope capsule radiation level is only 7.9 mrem/hr unshielded at 1 m (neutrons and gamma).

  12. A nuclear source term analysis for spacecraft power systems

    International Nuclear Information System (INIS)

    McCulloch, W.H.

    1998-01-01

    All US space missions involving on board nuclear material must be approved by the Office of the President. To be approved the mission and the hardware systems must undergo evaluations of the associated nuclear health and safety risk. One part of these evaluations is the characterization of the source terms, i.e., the estimate of the amount, physical form, and location of nuclear material, which might be released into the environment in the event of credible accidents. This paper presents a brief overview of the source term analysis by the Interagency Nuclear Safety Review Panel for the NASA Cassini Space Mission launched in October 1997. Included is a description of the Energy Interaction Model, an innovative approach to the analysis of potential releases from high velocity impacts resulting from launch aborts and reentries

  13. Future spacecraft propulsion systems. Enabling technologies for space exploration. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Czysz, Paul A. [St. Louis Univ., MO (United States). Oliver L. Parks Endowed Chair in Aerospace Engineering; Bruno, Claudio [Univ. degli Studi di Roma (Italy). Dipt. di Meccanica e Aeronautica

    2009-07-01

    In this second edition of Future Spacecraft Propulsion Systems, the authors demonstrate the need to break free from the old established concepts of expendable rockets, using chemical propulsion, and to develop new breeds of launch vehicle capable of both launching payloads into orbit at a dramatically reduced cost and for sustained operations in low-Earth orbit. The next steps to establishing a permanent 'presence' in the Solar System beyond Earth are the commercialisation of sustained operations on the Moon and the development of advanced nuclear or high-energy space propulsion systems for Solar System exploration out to the boundary of interstellar space. In the future, high-energy particle research facilities may one day yield a very high-energy propulsion system that will take us to the nearby stars, or even beyond. Space is not quiet: it is a continuous series of nuclear explosions that provide the material for new star systems to form and provide the challenge to explore. This book provides an assessment of the industrial capability required to construct and operate the necessary spacecraft. Time and distance communication and control limitations impose robotic constraints. Space environments restrict human sustained presence and put high demands on electronic, control and materials systems. This comprehensive and authoritative book puts spacecraft propulsion systems in perspective, from earth orbit launchers to astronomical/space exploration vehicles. It includes new material on fusion propulsion, new figures and updates and expands the information given in the first edition. (orig.)

  14. Adaptation and Re-Use of Spacecraft Power System Models for the Constellation Program

    Science.gov (United States)

    Hojnicki, Jeffrey S.; Kerslake, Thomas W.; Ayres, Mark; Han, Augustina H.; Adamson, Adrian M.

    2008-01-01

    NASA's Constellation Program is embarking on a new era of space exploration, returning to the Moon and beyond. The Constellation architecture will consist of a number of new spacecraft elements, including the Orion crew exploration vehicle, the Altair lunar lander, and the Ares family of launch vehicles. Each of these new spacecraft elements will need an electric power system, and those power systems will need to be designed to fulfill unique mission objectives and to survive the unique environments encountered on a lunar exploration mission. As with any new spacecraft power system development, preliminary design work will rely heavily on analysis to select the proper power technologies, size the power system components, and predict the system performance throughout the required mission profile. Constellation projects have the advantage of leveraging power system modeling developments from other recent programs such as the International Space Station (ISS) and the Mars Exploration Program. These programs have developed mature power system modeling tools, which can be quickly modified to meet the unique needs of Constellation, and thus provide a rapid capability for detailed power system modeling that otherwise would not exist.

  15. Low-Cost, Class D Testing of Spacecraft Photovoltaic Systems Can Reduce Risk

    Science.gov (United States)

    Forgione, Joshua B.; Kojima, Gilbert K.; Hanel, Robert; Mallinson, Mark V.

    2014-01-01

    The end-to-end verification of a spacecraft photovoltaic power generation system requires light! Specifically, the standard practice for doing so is the Large Area Pulsed Solar Simulation (LAPSS). A LAPSS test can characterize a photovoltaic system's efficiency via its response to rapidly applied impulses of simulated sunlight. However, a Class D program on a constrained budget and schedule may not have the resources to ship an entire satellite for a LAPSS test alone. Such was the case with the Lunar Atmospheric and Dust Environment Explorer (LADEE) program, which was also averse to the risk of hardware damage during shipment. When the Electrical Power System (EPS) team was denied a spacecraft-level LAPSS test, the lack of an end-to-end power generation test elevated to a project-level technical risk. The team pulled together very limited resources to not only eliminate the risk, but build a process to monitor the health of the system through mission operations. We discuss a process for performing a low-cost, end-to-end test of the LADEE photovoltaic system. The approach combines system-level functional test, panel-level performance results, and periodic inspection (and repair) up until launch. Following launch, mission operations tools are utilized to assess system performance based on a scant amount of data. The process starts in manufacturing at the subcontractor. The panel manufacturer provides functional test and LAPSS data on each individual panel. We apply an initial assumption that the per-panel performance is sufficient to meet the power generation requirements. The manufacturer's data is also carried as the performance allocation for each panel during EPS system modeling and initial mission operations. During integration and test, a high-power, professional theater lamp system provides simulated sunlight to each panel on the spacecraft, thereby permitting a true end-to-end system test. A passing test results in a step response to nearly full-rated current

  16. Adaptive Jacobian Fuzzy Attitude Control for Flexible Spacecraft Combined Attitude and Sun Tracking System

    Science.gov (United States)

    Chak, Yew-Chung; Varatharajoo, Renuganth

    2016-07-01

    Many spacecraft attitude control systems today use reaction wheels to deliver precise torques to achieve three-axis attitude stabilization. However, irrecoverable mechanical failure of reaction wheels could potentially lead to mission interruption or total loss. The electrically-powered Solar Array Drive Assemblies (SADA) are usually installed in the pitch axis which rotate the solar arrays to track the Sun, can produce torques to compensate for the pitch-axis wheel failure. In addition, the attitude control of a flexible spacecraft poses a difficult problem. These difficulties include the strong nonlinear coupled dynamics between the rigid hub and flexible solar arrays, and the imprecisely known system parameters, such as inertia matrix, damping ratios, and flexible mode frequencies. In order to overcome these drawbacks, the adaptive Jacobian tracking fuzzy control is proposed for the combined attitude and sun-tracking control problem of a flexible spacecraft during attitude maneuvers in this work. For the adaptation of kinematic and dynamic uncertainties, the proposed scheme uses an adaptive sliding vector based on estimated attitude velocity via approximate Jacobian matrix. The unknown nonlinearities are approximated by deriving the fuzzy models with a set of linguistic If-Then rules using the idea of sector nonlinearity and local approximation in fuzzy partition spaces. The uncertain parameters of the estimated nonlinearities and the Jacobian matrix are being adjusted online by an adaptive law to realize feedback control. The attitude of the spacecraft can be directly controlled with the Jacobian feedback control when the attitude pointing trajectory is designed with respect to the spacecraft coordinate frame itself. A significant feature of this work is that the proposed adaptive Jacobian tracking scheme will result in not only the convergence of angular position and angular velocity tracking errors, but also the convergence of estimated angular velocity to

  17. A historical overview of the electrical power systems in the US manned and some US unmanned spacecraft

    Science.gov (United States)

    Maisel, J. E.

    1984-01-01

    A historical overview of electrical power systems used in the U.S. manned spacecraft and some of the U.S. unmanned spacecraft is presented in this investigation. A time frame of approximately 25 years, the period for 1959 to 1984, is covered in this report. Results indicate that the nominal bus voltage was 28 volts dc in most spacecraft and all other voltage levels were derived from this voltage through such techniques as voltage inversion or rectification, or a combination. Most spacecraft used solar arrays for the main source of power except for those spacecraft that had a relatively short flight duration, or deep spaceprobes that were designed for very long flight duration. Fuel cells were used on Gemini, Apollo, and Space Shuttle (short duration flights) while radioisotope thermoelectric generators were employed on the Pioneer, Jupiter/Saturn, Viking Lander, and Voyager spacecraft (long duration flights). The main dc bus voltage was unregulated on the manned spacecraft with voltage regulation provided at the user loads. A combination of regulated, semiregulated, and unregulated buses were used on the unmanned spacecraft depending on the type of load. For example, scientific instruments were usually connected to regulated buses while fans, relays, etc. were energized from an unregulated bus. Different forms of voltage regulation, such as shunt, buck/boot, and pulse-width modulated regulators, were used. This report includes a comprehensive bibliography on spacecraft electrical power systems for the space programs investigated.

  18. Space Launch System Spacecraft and Payload Elements: Progress Toward Crewed Launch and Beyond

    Science.gov (United States)

    Schorr, Andrew A.; Smith, David Alan; Holcomb, Shawn; Hitt, David

    2017-01-01

    While significant and substantial progress continues to be accomplished toward readying the Space Launch System (SLS) rocket for its first test flight, work is already underway on preparations for the second flight - using an upgraded version of the vehicle - and beyond. Designed to support human missions into deep space, SLS is the most powerful human-rated launch vehicle the United States has ever undertaken, and is one of three programs being managed by the National Aeronautics and Space Administration's (NASA's) Exploration Systems Development division. The Orion spacecraft program is developing a new crew vehicle that will support human missions beyond low Earth orbit (LEO), and the Ground Systems Development and Operations (GSDO) program is transforming Kennedy Space Center (KSC) into a next-generation spaceport capable of supporting not only SLS but also multiple commercial users. Together, these systems will support human exploration missions into the proving ground of cislunar space and ultimately to Mars. For its first flight, SLS will deliver a near-term heavy-lift capability for the nation with its 70-metric-ton (t) Block 1 configuration. Each element of the vehicle now has flight hardware in production in support of the initial flight of the SLS, which will propel Orion around the moon and back. Encompassing hardware qualification, structural testing to validate hardware compliance and analytical modeling, progress is on track to meet the initial targeted launch date. In Utah and Mississippi, booster and engine testing are verifying upgrades made to proven shuttle hardware. At Michoud Assembly Facility (MAF) in Louisiana, the world's largest spacecraft welding tool is producing tanks for the SLS core stage. Providing the Orion crew capsule/launch vehicle interface and in-space propulsion via a cryogenic upper stage, the Spacecraft/Payload Integration and Evolution (SPIE) element serves a key role in achieving SLS goals and objectives. The SPIE element

  19. The Preliminary Design of a Standardized Spacecraft Bus for Small Tactical Satellites (Volume 2)

    Science.gov (United States)

    1996-11-01

    Module Inowerio Moddlile PoTanpotaio 0,03d Sysem0es90.47 MMino MCost~, Miemf MindCostofLaune 0.1541 0.1072 Max Me Tonna Availabilit ProgrmsRis 00.1776...shot propulsion; usually used for orbit insertion in launch systems LIQUID Water Electrolysis Complicated; not developed for commercial use; high...spills and leaks. Since hydrazine reacts with air, as well as some metal oxides and oxidizing agents, and absorbs water readily, storage and transport

  20. Development of a Low-Cost Method for Whole-Spacecraft Isolation of Small Satellites

    Science.gov (United States)

    2017-01-10

    of motion for the 2DOF system in matrix form are shown in Equation 2.5, assuming c1 is zero [24]).[ m1 0 0 m2 ][ ẍ1 ẍ2 ] + [ c2 −c2 −c2 c2 ][ ẋ1...response functions (FRF) between the base and each mass, H1 and H2, can be calculated by taking the inverse of the impedance matrix , which is defined...eig(K,M); % natural frequencies lambda =sqrt(nonzeros(d)); freq= lambda /(2*pi); %Hz omega = 20*2*pi:1*2*pi:2000*2*pi; % damped frequencies zheta=0.01; wd

  1. An Integrated Vision-Based System for Spacecraft Attitude and Topology Determination for Formation Flight Missions

    Science.gov (United States)

    Rogers, Aaron; Anderson, Kalle; Mracek, Anna; Zenick, Ray

    2004-01-01

    With the space industry's increasing focus upon multi-spacecraft formation flight missions, the ability to precisely determine system topology and the orientation of member spacecraft relative to both inertial space and each other is becoming a critical design requirement. Topology determination in satellite systems has traditionally made use of GPS or ground uplink position data for low Earth orbits, or, alternatively, inter-satellite ranging between all formation pairs. While these techniques work, they are not ideal for extension to interplanetary missions or to large fleets of decentralized, mixed-function spacecraft. The Vision-Based Attitude and Formation Determination System (VBAFDS) represents a novel solution to both the navigation and topology determination problems with an integrated approach that combines a miniature star tracker with a suite of robust processing algorithms. By combining a single range measurement with vision data to resolve complete system topology, the VBAFDS design represents a simple, resource-efficient solution that is not constrained to certain Earth orbits or formation geometries. In this paper, analysis and design of the VBAFDS integrated guidance, navigation and control (GN&C) technology will be discussed, including hardware requirements, algorithm development, and simulation results in the context of potential mission applications.

  2. Night vision imaging system design, integration and verification in spacecraft vacuum thermal test

    Science.gov (United States)

    Shang, Yonghong; Wang, Jing; Gong, Zhe; Li, Xiyuan; Pei, Yifei; Bai, Tingzhu; Zhen, Haijing

    2015-08-01

    The purposes of spacecraft vacuum thermal test are to characterize the thermal control systems of the spacecraft and its component in its cruise configuration and to allow for early retirement of risks associated with mission-specific and novel thermal designs. The orbit heat flux is simulating by infrared lamp, infrared cage or electric heater. As infrared cage and electric heater do not emit visible light, or infrared lamp just emits limited visible light test, ordinary camera could not operate due to low luminous density in test. Moreover, some special instruments such as satellite-borne infrared sensors are sensitive to visible light and it couldn't compensate light during test. For improving the ability of fine monitoring on spacecraft and exhibition of test progress in condition of ultra-low luminous density, night vision imaging system is designed and integrated by BISEE. System is consist of high-gain image intensifier ICCD camera, assistant luminance system, glare protect system, thermal control system and computer control system. The multi-frame accumulation target detect technology is adopted for high quality image recognition in captive test. Optical system, mechanical system and electrical system are designed and integrated highly adaptable to vacuum environment. Molybdenum/Polyimide thin film electrical heater controls the temperature of ICCD camera. The results of performance validation test shown that system could operate under vacuum thermal environment of 1.33×10-3Pa vacuum degree and 100K shroud temperature in the space environment simulator, and its working temperature is maintains at 5° during two-day test. The night vision imaging system could obtain video quality of 60lp/mm resolving power.

  3. Development of the solar array deployment and drive system for the XTE spacecraft

    Science.gov (United States)

    Farley, Rodger; Ngo, Son

    1995-01-01

    The X-ray Timing Explorer (XTE) spacecraft is a NASA science low-earth orbit explorer-class satellite to be launched in 1995, and is an in-house Goddard Space Flight Center (GSFC) project. It has two deployable aluminum honeycomb solar array wings with each wing being articulated by a single axis solar array drive assembly. This paper will address the design, the qualification testing, and the development problems as they surfaced of the Solar Array Deployment and Drive System.

  4. Particulate Matter Filtration Design Considerations for Crewed Spacecraft Life Support Systems

    Science.gov (United States)

    Agui, Juan H.; Vijayakumar, R.; Perry, Jay L.

    2016-01-01

    Particulate matter filtration is a key component of crewed spacecraft cabin ventilation and life support system (LSS) architectures. The basic particulate matter filtration functional requirements as they relate to an exploration vehicle LSS architecture are presented. Particulate matter filtration concepts are reviewed and design considerations are discussed. A concept for a particulate matter filtration architecture suitable for exploration missions is presented. The conceptual architecture considers the results from developmental work and incorporates best practice design considerations.

  5. Dynamic Isotope Power System (DIPS) Applications Study. Volume II. Nuclear Integrated Multimission Spacecraft (NIMS) design definition. Final report

    International Nuclear Information System (INIS)

    1979-11-01

    The design requirements for the Nuclear Integrated Multimission Spacecraft. (NIMS) are discussed in detail. The requirements are a function of mission specifications, payload, control system requirements, electric system specifications, and cost limitations

  6. Water electrolysis system - H2 and O2 generation. [for spacecraft atmosphere revitalization

    Science.gov (United States)

    Schubert, F. H.; Lee, M. K.; Davenport, R. J.; Quattrone, P. D.

    1978-01-01

    An oxygen generation system design based on the static feed water electrolysis concept is described. The system is designed to generate 4.20 kg/d of oxygen to satisfy the metabolic needs of a three-person crew, to compensate for spacecraft leakage, and to provide the oxygen required by the electrochemical depolarized CO2 concentrator. The system has a fixed hardware weight of 75 kg, occupies a volume of 0.11 cu m, and requires only 1.1 kw of electrical power. The static feed electrolysis concept is discussed, and experimental data on the high-performance electrode are presented.

  7. Resilience Engineering in Critical Long Term Aerospace Software Systems: A New Approach to Spacecraft Software Safety

    Science.gov (United States)

    Dulo, D. A.

    Safety critical software systems permeate spacecraft, and in a long term venture like a starship would be pervasive in every system of the spacecraft. Yet software failure today continues to plague both the systems and the organizations that develop them resulting in the loss of life, time, money, and valuable system platforms. A starship cannot afford this type of software failure in long journeys away from home. A single software failure could have catastrophic results for the spaceship and the crew onboard. This paper will offer a new approach to developing safe reliable software systems through focusing not on the traditional safety/reliability engineering paradigms but rather by focusing on a new paradigm: Resilience and Failure Obviation Engineering. The foremost objective of this approach is the obviation of failure, coupled with the ability of a software system to prevent or adapt to complex changing conditions in real time as a safety valve should failure occur to ensure safe system continuity. Through this approach, safety is ensured through foresight to anticipate failure and to adapt to risk in real time before failure occurs. In a starship, this type of software engineering is vital. Through software developed in a resilient manner, a starship would have reduced or eliminated software failure, and would have the ability to rapidly adapt should a software system become unstable or unsafe. As a result, long term software safety, reliability, and resilience would be present for a successful long term starship mission.

  8. Robust control for spacecraft rendezvous system with actuator unsymmetrical saturation: a gain scheduling approach

    Science.gov (United States)

    Wang, Qian; Xue, Anke

    2018-06-01

    This paper has proposed a robust control for the spacecraft rendezvous system by considering the parameter uncertainties and actuator unsymmetrical saturation based on the discrete gain scheduling approach. By changing of variables, we transform the actuator unsymmetrical saturation control problem into a symmetrical one. The main advantage of the proposed method is improving the dynamic performance of the closed-loop system with a region of attraction as large as possible. By the Lyapunov approach and the scheduling technology, the existence conditions for the admissible controller are formulated in the form of linear matrix inequalities. The numerical simulation illustrates the effectiveness of the proposed method.

  9. Development status of solid polymer electrolyte water electrolysis for manned spacecraft life support systems

    Science.gov (United States)

    Nuttall, L. J.; Titterington, W. A.

    1974-01-01

    Details of the design and system verification test results are presented for a six-man-rated oxygen generation system. The system configuration incorporates components and instrumentation for computer-controlled operation with automatic start-up/shutdown sequencing, fault detection and isolation, and with self-contained sensors and controls for automatic safe emergency shutdown. All fluid and electrical components, sensors, and electronic controls are designed to be easily maintainable under zero-gravity conditions. On-board component spares are utilized in the system concept to sustain long-term operation (six months minimum) in a manned spacecraft application. The system is centered on a 27-cell solid polymer electrolyte water electrolysis module which, combined with the associated system components and controls, forms a total system envelope 40 in. high, 40 in. wide, and 30 in. deep.

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

    Science.gov (United States)

    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.

  11. Concurrent System Engineering and Risk Reduction for Dual-Band (RF/optical) Spacecraft Communications

    Science.gov (United States)

    Fielhauer, Karl, B.; Boone, Bradley, G.; Raible, Daniel, E.

    2012-01-01

    This paper describes a system engineering approach to examining the potential for combining elements of a deep-space RF and optical communications payload, for the purpose of reducing the size, weight and power burden on the spacecraft and the mission. Figures of merit and analytical methodologies are discussed to conduct trade studies, and several potential technology integration strategies are presented. Finally, the NASA Integrated Radio and Optical Communications (iROC) project is described, which directly addresses the combined RF and optical approach.

  12. Small Aircraft Data Distribution System

    Science.gov (United States)

    Chazanoff, Seth L.; Dinardo, Steven J.

    2012-01-01

    The CARVE Small Aircraft Data Distribution System acquires the aircraft location and attitude data that is required by the various programs running on a distributed network. This system distributes the data it acquires to the data acquisition programs for inclusion in their data files. It uses UDP (User Datagram Protocol) to broadcast data over a LAN (Local Area Network) to any programs that might have a use for the data. The program is easily adaptable to acquire additional data and log that data to disk. The current version also drives displays using precision pitch and roll information to aid the pilot in maintaining a level-level attitude for radar/radiometer mapping beyond the degree available by flying visually or using a standard gyro-driven attitude indicator. The software is designed to acquire an array of data to help the mission manager make real-time decisions as to the effectiveness of the flight. This data is displayed for the mission manager and broadcast to the other experiments on the aircraft for inclusion in their data files. The program also drives real-time precision pitch and roll displays for the pilot and copilot to aid them in maintaining the desired attitude, when required, during data acquisition on mapping lines.

  13. Post-capture vibration suppression of spacecraft via a bio-inspired isolation system

    Science.gov (United States)

    Dai, Honghua; Jing, Xingjian; Wang, Yu; Yue, Xiaokui; Yuan, Jianping

    2018-05-01

    Inspired by the smooth motions of a running kangaroo, a bio-inspired quadrilateral shape (BIQS) structure is proposed to suppress the vibrations of a free-floating spacecraft subject to periodic or impulsive forces, which may be encountered during on-orbit servicing missions. In particular, the BIQS structure is installed between the satellite platform and the capture mechanism. The dynamical model of the BIQS isolation system, i.e. a BIQS structure connecting the platform and the capture mechanism at each side, is established by Lagrange's equations to simulate the post-capture dynamical responses. The BIQS system suffering an impulsive force is dealt with by means of a modified version of Lagrange's equations. Furthermore, the classical harmonic balance method is used to solve the nonlinear dynamical system subject to periodic forces, while for the case under impulsive forces the numerical integration method is adopted. Due to the weightless environment in space, the present BIQS system is essentially an under-constrained dynamical system with one of its natural frequencies being identical to zero. The effects of system parameters, such as the number of layers in BIQS, stiffness, assembly angle, rod length, damping coefficient, masses of satellite platform and capture mechanism, on the isolation performance of the present system are thoroughly investigated. In addition, comparisons between the isolation performances of the presently proposed BIQS isolator and the conventional spring-mass-damper (SMD) isolator are conducted to demonstrate the advantages of the present isolator. Numerical simulations show that the BIQS system has a much better performance than the SMD system under either periodic or impulsive forces. Overall, the present BIQS isolator offers a highly efficient passive way for vibration suppressions of free-floating spacecraft.

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

    Science.gov (United States)

    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.

  15. Imaging Flash Lidar for Safe Landing on Solar System Bodies and Spacecraft Rendezvous and Docking

    Science.gov (United States)

    Amzajerdian, Farzin; Roback, Vincent E.; Bulyshev, Alexander E.; Brewster, Paul F.; Carrion, William A; Pierrottet, Diego F.; Hines, Glenn D.; Petway, Larry B.; Barnes, Bruce W.; Noe, Anna M.

    2015-01-01

    NASA has been pursuing flash lidar technology for autonomous, safe landing on solar system bodies and for automated rendezvous and docking. During the final stages of the landing from about 1 kilometer to 500 meters above the ground, the flash lidar can generate 3-Dimensional images of the terrain to identify hazardous features such as craters, rocks, and steep slopes. The onboard flight computer can then use the 3-D map of terrain to guide the vehicle to a safe location. As an automated rendezvous and docking sensor, the flash lidar can provide relative range, velocity, and bearing from an approaching spacecraft to another spacecraft or a space station. NASA Langley Research Center has developed and demonstrated a flash lidar sensor system capable of generating 16,000 pixels range images with 7 centimeters precision, at 20 Hertz frame rate, from a maximum slant range of 1800 m from the target area. This paper describes the lidar instrument and presents the results of recent flight tests onboard a rocket-propelled free-flyer vehicle (Morpheus) built by NASA Johnson Space Center. The flights were conducted at a simulated lunar terrain site, consisting of realistic hazard features and designated landing areas, built at NASA Kennedy Space Center specifically for this demonstration test. This paper also provides an overview of the plan for continued advancement of the flash lidar technology aimed at enhancing its performance to meet both landing and automated rendezvous and docking applications.

  16. Systems Engineering Using Heritage Spacecraft Technology: Lessons Learned from Discovery and New Frontiers Deep Space Missions

    Science.gov (United States)

    Barley, Bryan; Newhouse, Marilyn; Clardy, Dennon

    2011-01-01

    In the design and development of complex spacecraft missions, project teams frequently assume the use of advanced technology or heritage systems to enable a mission or reduce the overall mission risk and cost. As projects proceed through the development life cycle, increasingly detailed knowledge of the advanced or heritage systems and the system environment identifies unanticipated issues that result in cost overruns or schedule impacts. The Discovery & New Frontiers (D&NF) Program Office recently studied cost overruns and schedule delays resulting from advanced technology or heritage assumptions for 6 D&NF 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 the cost and schedule growth did not result from technical hurdles requiring significant technology development. Instead, systems engineering processes did not identify critical issues early enough in the design cycle to ensure project schedules and estimated costs address the inherent risks. In general, the overruns were traceable to: inadequate understanding of the heritage system s behavior within the proposed spacecraft design and mission environment; an insufficient level of experience with the heritage system; or an inadequate scoping of the system-wide impacts necessary to implement the heritage or advanced technology. This presentation summarizes the study s findings and offers suggestions for improving the project s ability to identify and manage the risks inherent in the technology and heritage design solution.

  17. A fuzzy logic intelligent diagnostic system for spacecraft integrated vehicle health management

    Science.gov (United States)

    Wu, G. Gordon

    1995-01-01

    Due to the complexity of future space missions and the large amount of data involved, greater autonomy in data processing is demanded for mission operations, training, and vehicle health management. In this paper, we develop a fuzzy logic intelligent diagnostic system to perform data reduction, data analysis, and fault diagnosis for spacecraft vehicle health management applications. The diagnostic system contains a data filter and an inference engine. The data filter is designed to intelligently select only the necessary data for analysis, while the inference engine is designed for failure detection, warning, and decision on corrective actions using fuzzy logic synthesis. Due to its adaptive nature and on-line learning ability, the diagnostic system is capable of dealing with environmental noise, uncertainties, conflict information, and sensor faults.

  18. A Spacecraft Housekeeping System-on-Chip in a Radiation Hardened Structured ASIC

    Science.gov (United States)

    Suarez, George; DuMonthier, Jeffrey J.; Sheikh, Salman S.; Powell, Wesley A.; King, Robyn L.

    2012-01-01

    Housekeeping systems are essential to health monitoring of spacecraft and instruments. Typically, sensors are distributed across various sub-systems and data is collected using components such as analog-to-digital converters, analog multiplexers and amplifiers. In most cases programmable devices are used to implement the data acquisition control and storage, and the interface to higher level systems. Such discrete implementations require additional size, weight, power and interconnect complexity versus an integrated circuit solution, as well as the qualification of multiple parts. Although commercial devices are readily available, they are not suitable for space applications due the radiation tolerance and qualification requirements. The Housekeeping System-o n-A-Chip (HKSOC) is a low power, radiation hardened integrated solution suitable for spacecraft and instrument control and data collection. A prototype has been designed and includes a wide variety of functions including a 16-channel analog front-end for driving and reading sensors, analog-to-digital and digital-to-analog converters, on-chip temperature sensor, power supply current sense circuits, general purpose comparators and amplifiers, a 32-bit processor, digital I/O, pulse-width modulation (PWM) generators, timers and I2C master and slave serial interfaces. In addition, the device can operate in a bypass mode where the processor is disabled and external logic is used to control the analog and mixed signal functions. The device is suitable for stand-alone or distributed systems where multiple chips can be deployed across different sub-systems as intelligent nodes with computing and processing capabilities.

  19. Isolation, pointing, and suppression (IPS) system for high-performance spacecraft

    Science.gov (United States)

    Hindle, Tim; Davis, Torey; Fischer, Jim

    2007-04-01

    Passive mechanical isolation is often times the first step taken to remedy vibration issues on-board a spacecraft. In many cases, this is done with a hexapod of axial members or struts to obtain the desired passive isolation in all six degrees-of-freedom (DOF). In some instances, where the disturbance sources are excessive or the payload is particularly sensitive to vibration, additional steps are taken to improve the performance beyond that of passive isolation. Additional performance or functionality can be obtained with the addition of active control, using a hexapod of hybrid (passive/active) elements at the interface between the payload and the bus. This paper describes Honeywell's Isolation, Pointing, and Suppression (IPS) system. It is a hybrid isolation system designed to isolate a sensitive spacecraft payload with very low passive resonant break frequencies while affording agile independent payload pointing, on-board payload disturbance rejection, and active isolation augmentation. This system is an extension of the work done on Honeywell's previous Vibration Isolation, Steering, and Suppression (VISS) flight experiment. Besides being designed for a different size payload than VISS, the IPS strut includes a dual-stage voice coil design for improved dynamic range as well as improved low-noise drive electronics. In addition, the IPS struts include integral load cells, gap sensors, and payloadside accelerometers for control and telemetry purposes. The associated system-level control architecture to accomplish these tasks is also new for this program as compared to VISS. A summary of the IPS system, including analysis and hardware design, build, and single axis bipod testing will be reviewed.

  20. 42: An Open-Source Simulation Tool for Study and Design of Spacecraft Attitude Control Systems

    Science.gov (United States)

    Stoneking, Eric

    2018-01-01

    Simulation is an important tool in the analysis and design of spacecraft attitude control systems. The speaker will discuss the simulation tool, called simply 42, that he has developed over the years to support his own work as an engineer in the Attitude Control Systems Engineering Branch at NASA Goddard Space Flight Center. 42 was intended from the outset to be high-fidelity and powerful, but also fast and easy to use. 42 is publicly available as open source since 2014. The speaker will describe some of 42's models and features, and discuss its applicability to studies ranging from early concept studies through the design cycle, integration, and operations. He will outline 42's architecture and share some thoughts on simulation development as a long-term project.

  1. Biofilm formation and control in a simulated spacecraft water system - Interim results

    Science.gov (United States)

    Schultz, John R.; Taylor, Robert D.; Flanagan, David T.; Gibbons, Randall E.; Brown, Harlan D.; Sauer, Richard L.

    1989-01-01

    The ability of iodine to control microbial contamination and biofilm formation in spacecraft water distribution systems is studied using two stainless steel water subsystems. One subsystem has an iodine level of 2.5 mg/L maintained by an iodinated ion-exchange resin. The other subsystem has no iodine added. Stainless steel coupons are removed from each system to monitor biofilm formation. Results from the first six months of operation indicate that 2.5 mg/L of iodine has limited the number of viable bacteria that can be recovered from the iodinated subsystem. Epifluorescence microscopy of the coupons taken from this subsystem, however, indicates some evidence of microbial colonization after 15 weeks of operation. Numerous bacteria have been continually removed from both the water samples and the coupons taken from the noniodinated subsystem after only 3 weeks of operation.

  2. Use of two-phase flow heat transfer method in spacecraft thermal system

    Science.gov (United States)

    Hye, A.

    1985-01-01

    In space applications, weight, volume and power are critical parameters. Presently liquid freon is used in the radiator planels of the Space Shuttle to dissipate heat. This requires a large amount of freon, large power for pumps, large volume and weight. Use of two-phase flow method to transfer heat can reduce them significantly. A modified commercial vapor compression refrigerator/freezer was sucessfully flown in STS-4 to study the effect of zero-gravity on the system. The duty cycle was about 5 percent higher in flight as compared to that on earth due to low flow velocity in condenser. The vapor Reynolds number at exit was about 4000 as compared to about 12,000. Efforts are underway to design a refrigerator/freezer using an oil-free compressor for Spacelab Mission 4 scheduled to fly in January 1986. A thermal system can be designed for spacecraft using the two-phase flow to transfer heat economically.

  3. Small solar system bodies as granular systems

    Science.gov (United States)

    Hestroffer, Daniel; Campo Bagatín, Adriano; Losert, Wolfgang; Opsomer, Eric; Sánchez, Paul; Scheeres, Daniel J.; Staron, Lydie; Taberlet, Nicolas; Yano, Hajime; Eggl, Siegfried; Lecomte, Charles-Edouard; Murdoch, Naomi; Radjai, Fahrang; Richardson, Derek C.; Salazar, Marcos; Schwartz, Stephen R.; Tanga, Paolo

    2017-06-01

    Asteroids and other Small Solar System Bodies (SSSBs) are currently of great scientific and even industrial interest. Asteroids exist as the permanent record of the formation of the Solar System and therefore hold many clues to its understanding as a whole, as well as insights into the formation of planetary bodies. Additionally, SSSBs are being investigated in the context of impact risks for the Earth, space situational awareness and their possible industrial exploitation (asteroid mining). In all these aspects, the knowledge of the geophysical characteristics of SSSB surface and internal structure are of great importance. Given their size, constitution, and the evidence that many SSSBs are not simple monoliths, these bodies should be studied and modelled as self-gravitating granular systems in general, or as granular systems in micro-gravity environments in particular contexts. As such, the study of the geophysical characteristics of SSSBs is a multi-disciplinary effort that lies at the crossroads between Granular Mechanics, Celestial Mechanics, Soil Mechanics, Aerospace Engineering and Computer Sciences.

  4. Disinfection of Spacecraft Potable Water Systems by Photocatalytic Oxidation Using UV-A Light Emitting Diodes

    Science.gov (United States)

    Birmele, Michele N.; O'Neal, Jeremy A.; Roberts, Michael S.

    2011-01-01

    Ultraviolet (UV) light has long been used in terrestrial water treatment systems for photodisinfection and the removal of organic compounds by several processes including photoadsorption, photolysis, and photocatalytic oxidation/reduction. Despite its effectiveness for water treatment, UV has not been explored for spacecraft applications because of concerns about the safety and reliability of mercury-containing UV lamps. However, recent advances in ultraviolet light emitting diodes (UV LEDs) have enabled the utilization of nanomaterials that possess the appropriate optical properties for the manufacture of LEDs capable of producing monochromatic light at germicidal wavelengths. This report describes the testing of a commercial-off-the-shelf, high power Nichia UV-A LED (250mW A365nnJ for the excitation of titanium dioxide as a point-of-use (POD) disinfection device in a potable water system. The combination of an immobilized, high surface area photocatalyst with a UV-A LED is promising for potable water system disinfection since toxic chemicals and resupply requirements are reduced. No additional consumables like chemical biocides, absorption columns, or filters are required to disinfect and/or remove potentially toxic disinfectants from the potable water prior to use. Experiments were conducted in a static test stand consisting of a polypropylene microtiter plate containing 3mm glass balls coated with titanium dioxide. Wells filled with water were exposed to ultraviolet light from an actively-cooled UV-A LED positioned above each well and inoculated with six individual challenge microorganisms recovered from the International Space Station (ISS): Burkholderia cepacia, Cupriavidus metallidurans, Methylobacterium fujisawaense, Pseudomonas aeruginosa, Sphingomonas paucimobilis and Wautersia basilensis. Exposure to the Nichia UV-A LED with photocatalytic oxidation resulted in a complete (>7-log) reduction of each challenge bacteria population in UV-A LEDs and semi

  5. Nonlinear guided wave circular array system for microcrack monitoring in spacecraft, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Reliable monitoring of the microcrack formation in the complex composite structure components in NASA spacecraft and launch vehicles is critical for vehicle...

  6. Launch Lock Assemblies Including Axial Gap Amplification Devices and Spacecraft Isolation Systems Including the Same

    Science.gov (United States)

    Barber, Tim Daniel (Inventor); Hindle, Timothy (Inventor); Young, Ken (Inventor); Davis, Torey (Inventor)

    2014-01-01

    Embodiments of a launch lock assembly are provided, as are embodiments of a spacecraft isolation system including one or more launch lock assemblies. In one embodiment, the launch lock assembly includes first and second mount pieces, a releasable clamp device, and an axial gap amplification device. The releasable clamp device normally maintains the first and second mount pieces in clamped engagement; and, when actuated, releases the first and second mount pieces from clamped engagement to allow relative axial motion there between. The axial gap amplification device normally residing in a blocking position wherein the gap amplification device obstructs relative axial motion between the first and second mount pieces. The axial gap amplification device moves into a non-blocking position when the first and second mount pieces are released from clamped engagement to increase the range of axial motion between the first and second mount pieces.

  7. Spacecraft Charge Monitor

    Science.gov (United States)

    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.

  8. Implementing model-based system engineering for the whole lifecycle of a spacecraft

    Science.gov (United States)

    Fischer, P. M.; Lüdtke, D.; Lange, C.; Roshani, F.-C.; Dannemann, F.; Gerndt, A.

    2017-09-01

    Design information of a spacecraft is collected over all phases in the lifecycle of a project. A lot of this information is exchanged between different engineering tasks and business processes. In some lifecycle phases, model-based system engineering (MBSE) has introduced system models and databases that help to organize such information and to keep it consistent for everyone. Nevertheless, none of the existing databases approached the whole lifecycle yet. Virtual Satellite is the MBSE database developed at DLR. It has been used for quite some time in Phase A studies and is currently extended for implementing it in the whole lifecycle of spacecraft projects. Since it is unforeseeable which future use cases such a database needs to support in all these different projects, the underlying data model has to provide tailoring and extension mechanisms to its conceptual data model (CDM). This paper explains the mechanisms as they are implemented in Virtual Satellite, which enables extending the CDM along the project without corrupting already stored information. As an upcoming major use case, Virtual Satellite will be implemented as MBSE tool in the S2TEP project. This project provides a new satellite bus for internal research and several different payload missions in the future. This paper explains how Virtual Satellite will be used to manage configuration control problems associated with such a multi-mission platform. It discusses how the S2TEP project starts using the software for collecting the first design information from concurrent engineering studies, then making use of the extension mechanisms of the CDM to introduce further information artefacts such as functional electrical architecture, thus linking more and more processes into an integrated MBSE approach.

  9. Influence of a new generation of operations support systems on current spacecraft operations philosophy: The users feedback

    Science.gov (United States)

    Darroy, Jean Michel

    1993-01-01

    Current trends in the spacecraft mission operations area (spacecraft & mission complexity, project duration, required flexibility are requiring a breakthrough for what concerns philosophy, organization, and support tools. A major evolution is related to space operations 'informationalization', i.e adding to existing operations support & data processing systems a new generation of tools based on advanced information technologies (object-oriented programming, artificial intelligence, data bases, hypertext) that automate, at least partially, operations tasks that used be performed manually (mission & project planning/scheduling, operations procedures elaboration & execution, data analysis & failure diagnosis). All the major facets of this 'informationalization' are addressed at MATRA MARCONI SPACE, operational applications were fielded and generic products are becoming available. These various applications have generated a significant feedback from the users (at ESA, CNES, ARIANESPACE, MATRA MARCONI SPACE), which is now allowing us to precisely measure how the deployment of this new generation of tools, that we called OPSWARE, can 'reengineer' current spacecraft mission operations philosophy, how it can make space operations faster, better, and cheaper. This paper can be considered as an update of the keynote address 'Knowledge-Based Systems for Spacecraft Control' presented during the first 'Ground Data Systems for Spacecraft Control' conference in Darmstadt, June 1990, with a special emphasis on these last two years users feedback.

  10. (abstract) ARGOS: a System to Monitor Ulysses Nutation and Thruster Firings from Variations of the Spacecraft Radio Signal

    Science.gov (United States)

    McElrath, T. P.; Cangahuala, L. A.; Miller, K. J.; Stravert, L. R.; Garcia-Perez, Raul

    1995-01-01

    Ulysses is a spin-stabilized spacecraft that experienced significant nutation after its launch in October 1990. This was due to the Sun-spacecraft-Earth geometry, and a study of the phenomenon predicted that the nutation would again be a problem during 1994-95. The difficulty of obtaining nutation estimates in real time from the spacecraft telemetry forced the ESA/NASA Ulysses Team to explore alternative information sources. The work performed by the ESA Operations Team provided a model for a system that uses the radio signal strength measurements to monitor the spacecraft dynamics. These measurements (referred to as AGC) are provided once per second by the tracking stations of the DSN. The system was named ARGOS (Attitude Reckoning from Ground Observable Signals) after the ever-vigilant, hundred-eyed giant of Greek Mythology. The ARGOS design also included Doppler processing, because Doppler shifts indicate thruster firings commanded by the active nutation control carried out onboard the spacecraft. While there is some visibility into thruster activity from telemetry, careful processing of the high-sample-rate Doppler data provides an accurate means of detecting the presence and time of thruster firings. DSN Doppler measurements are available at a ten-per-second rate in the same tracking data block as the AGC data.

  11. Automated Performance Characterization of DSN System Frequency Stability Using Spacecraft Tracking Data

    Science.gov (United States)

    Pham, Timothy T.; Machuzak, Richard J.; Bedrossian, Alina; Kelly, Richard M.; Liao, Jason C.

    2012-01-01

    This software provides an automated capability to measure and qualify the frequency stability performance of the Deep Space Network (DSN) ground system, using daily spacecraft tracking data. The results help to verify if the DSN performance is meeting its specification, therefore ensuring commitments to flight missions; in particular, the radio science investigations. The rich set of data also helps the DSN Operations and Maintenance team to identify the trends and patterns, allowing them to identify the antennas of lower performance and implement corrective action in a timely manner. Unlike the traditional approach where the performance can only be obtained from special calibration sessions that are both time-consuming and require manual setup, the new method taps into the daily spacecraft tracking data. This new approach significantly increases the amount of data available for analysis, roughly by two orders of magnitude, making it possible to conduct trend analysis with good confidence. The software is built with automation in mind for end-to-end processing. From the inputs gathering to computation analysis and later data visualization of the results, all steps are done automatically, making the data production at near zero cost. This allows the limited engineering resource to focus on high-level assessment and to follow up with the exceptions/deviations. To make it possible to process the continual stream of daily incoming data without much effort, and to understand the results quickly, the processing needs to be automated and the data summarized at a high level. Special attention needs to be given to data gathering, input validation, handling anomalous conditions, computation, and presenting the results in a visual form that makes it easy to spot items of exception/deviation so that further analysis can be directed and corrective actions followed.

  12. Multi-Evaporator Miniature Loop Heat Pipe for Small Spacecraft Thermal Control. Part 1; New Technologies and Validation Approach

    Science.gov (United States)

    Ku, Jentung; Ottenstein, Laura; Douglas, Donya; Hoang, Triem

    2010-01-01

    Under NASA s New Millennium Program Space Technology 8 (ST 8) Project, four experiments Thermal Loop, Dependable Microprocessor, SAILMAST, and UltraFlex - were conducted to advance the maturity of individual technologies from proof of concept to prototype demonstration in a relevant environment , i.e. from a technology readiness level (TRL) of 3 to a level of 6. This paper presents the new technologies and validation approach of the Thermal Loop experiment. The Thermal Loop is an advanced thermal control system consisting of a miniature loop heat pipe (MLHP) with multiple evaporators and multiple condensers designed for future small system applications requiring low mass, low power, and compactness. The MLHP retains all features of state-of-the-art loop heat pipes (LHPs) and offers additional advantages to enhance the functionality, performance, versatility, and reliability of the system. Details of the thermal loop concept, technical advances, benefits, objectives, level 1 requirements, and performance characteristics are described. Also included in the paper are descriptions of the test articles and mathematical modeling used for the technology validation. An MLHP breadboard was built and tested in the laboratory and thermal vacuum environments for TRL 4 and TRL 5 validations, and an MLHP proto-flight unit was built and tested in a thermal vacuum chamber for the TRL 6 validation. In addition, an analytical model was developed to simulate the steady state and transient behaviors of the MLHP during various validation tests. Capabilities and limitations of the analytical model are also addressed.

  13. Design of a mission network system using SpaceWire for scientific payloads onboard the Arase spacecraft

    Science.gov (United States)

    Takashima, Takeshi; Ogawa, Emiko; Asamura, Kazushi; Hikishima, Mitsuru

    2018-05-01

    Arase is a small scientific satellite program conducted by the Institute of Space and Astronautical Science/Japan Aerospace Exploration Agency, which is dedicated to the detailed study of the radiation belts around Earth through in situ observations. In particular, the goal is to directly observe the interaction between plasma waves and particles, which cause the generation of high-energy electrons. To observe the waves and particles in detail, we must record large volumes of burst data with high transmission rates through onboard mission network systems. For this purpose, we developed a high-speed and highly reliable mission network based on SpaceWire, as well as a new and large memory data recorder equipped with a data search function based on observation time (the time index, TI, is the satellite time starting from when the spacecraft is powered on.) with respect to the orbital data generated in large quantities. By adopting a new transaction concept of a ring topology network with SpaceWire, we could secure a redundant mission network system without using large routers and having to suppress the increase in cable weight. We confirmed that their orbit performs as designed.[Figure not available: see fulltext.

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

    Data.gov (United States)

    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...

  15. Small Drinking Water Systems Communication and Outreach ...

    Science.gov (United States)

    As part of our small drinking water systems efforts, this poster highlights several communications and outreach highlights that EPA's Office of Research and Development and Office of Water have been undertaking in collaboration with states and the Association of State Drinking Water Administrators. To share information at EPA's annual small drinking water systems workshop

  16. Metal hydride hydrogen and heat storage systems as enabling technology for spacecraft applications

    Energy Technology Data Exchange (ETDEWEB)

    Reissner, Alexander, E-mail: reissner@fotec.at [FOTEC Forschungs- und Technologietransfer GmbH, Viktor Kaplan Straße 2, 2700 Wiener Neustadt (Austria); University of Applied Sciences Wiener Neustadt, Johannes Gutenberg-Straße 3, 2700 Wiener Neustadt (Austria); Pawelke, Roland H.; Hummel, Stefan; Cabelka, Dusan [FOTEC Forschungs- und Technologietransfer GmbH, Viktor Kaplan Straße 2, 2700 Wiener Neustadt (Austria); Gerger, Joachim [University of Applied Sciences Wiener Neustadt, Johannes Gutenberg-Straße 3, 2700 Wiener Neustadt (Austria); Farnes, Jarle, E-mail: Jarle.farnes@prototech.no [CMR Prototech AS, Fantoftvegen 38, PO Box 6034, 5892 Bergen (Norway); Vik, Arild; Wernhus, Ivar; Svendsen, Tjalve [CMR Prototech AS, Fantoftvegen 38, PO Box 6034, 5892 Bergen (Norway); Schautz, Max, E-mail: max.schautz@esa.int [European Space Agency, ESTEC – Keplerlaan 1, 2201 AZ Noordwijk Zh (Netherlands); Geneste, Xavier, E-mail: xavier.geneste@esa.int [European Space Agency, ESTEC – Keplerlaan 1, 2201 AZ Noordwijk Zh (Netherlands)

    2015-10-05

    Highlights: • A metal hydride tank concept for heat and hydrogen storage is presented. • The tank is part of a closed-loop reversible fuel cell system for space application. • For several engineering issues specific to the spacecraft application, solutions have been developed. • The effect of water contamination has been approximated for Ti-doped NaAlH{sub 4}. • A novel heat exchanger design has been realized by Selective Laser Melting. - Abstract: The next generation of telecommunication satellites will demand a platform payload performance in the range of 30+ kW within the next 10 years. At this high power output, a Regenerative Fuel Cell Systems (RFCS) offers an efficiency advantage in specific energy density over lithium ion batteries. However, a RFCS creates a substantial amount of heat (60–70 kJ per mol H{sub 2}) during fuel cell operation. This requires a thermal hardware that accounts for up to 50% of RFCS mass budget. Thus the initial advantage in specific energy density is reduced. A metal hydride tank for combined storage of heat and hydrogen in a RFCS may overcome this constraint. Being part of a consortium in an ongoing European Space Agency project, FOTEC is building a technology demonstrator for such a combined hydrogen and heat storage system.

  17. Dynamic of small photovoltaic systems

    Science.gov (United States)

    Mehrmann, A.; Kleinkauf, W.; Pigorsch, W.; Steeb, H.

    The results of 1.5 yr of field-testing of two photovoltaic (PV) power plants, one equipped with an electrolyzer and H2 storage, are reported. Both systems were interconnected with the grid and featured the PV module, a power conditioning unit, ac and dc load connections, and control units. The rated power of both units was 100 Wp. The system with electrolysis was governed by control laws which maximized the electrolyzer current. The tests underscored the preference for a power conditioning unit, rather than direct output to load connections. A 1 kWp system was developed in a follow-up program and will be tested in concert with electrolysis and interconnection with several grid customers. The program is geared to eventual development of larger units for utility-size applications.

  18. An IP-Based Software System for Real-time, Closed Loop, Multi-Spacecraft Mission Simulations

    Science.gov (United States)

    Cary, Everett; Davis, George; Higinbotham, John; Burns, Richard; Hogie, Keith; Hallahan, Francis

    2003-01-01

    This viewgraph presentation provides information on the architecture of a computerized testbest for simulating Distributed Space Systems (DSS) for controlling spacecraft flying in formation. The presentation also discusses and diagrams the Distributed Synthesis Environment (DSE) for simulating and planning DSS missions.

  19. Towards the Development of a Unified Distributed Date System for L1 Spacecraft

    Science.gov (United States)

    Lazarus, Alan J.; Kasper, Justin C.

    2005-01-01

    The purpose of this grant, 'Towards the Development of a Unified Distributed Data System for L1 Spacecraft', is to take the initial steps towards the development of a data distribution mechanism for making in-situ measurements more easily accessible to the scientific community. Our obligations as subcontractors to this grant are to add our Faraday Cup plasma data to this initial study and to contribute to the design of a general data distribution system. The year 1 objectives of the overall project as stated in the GSFC proposal are: 1) Both the rsync and Perl based data exchange tools will be fully developed and tested in our mixed, Unix, VMS, Windows and Mac OS X data service environment. Based on the performance comparisons, one will be selected and fully deployed. Continuous data exchange between all L1 solar wind monitors initiated. 2) Data version metadata will be agreed upon, fully documented, and deployed on our data sites. 3) The first version of the data description rules, encoded in a XML Schema, will be finalized. 4) Preliminary set of library routines will be collected, documentation standards and formats agreed on, and desirable routines that have not been implemented identified and assigned. 5) ViSBARD test site implemented to independently validate data mirroring procedures. The specific MIT tasks over the duration of this project are the following: a) implement mirroring service for WIND plasma data b) participate in XML Schema development c) contribute toward routine library.

  20. Preliminary Test of Adaptive Neuro-Fuzzy Inference System Controller for Spacecraft Attitude Control

    Directory of Open Access Journals (Sweden)

    Sung-Woo Kim

    2012-12-01

    Full Text Available The problem of spacecraft attitude control is solved using an adaptive neuro-fuzzy inference system (ANFIS. An ANFIS produces a control signal for one of the three axes of a spacecraft’s body frame, so in total three ANFISs are constructed for 3-axis attitude control. The fuzzy inference system of the ANFIS is initialized using a subtractive clustering method. The ANFIS is trained by a hybrid learning algorithm using the data obtained from attitude control simulations using state-dependent Riccati equation controller. The training data set for each axis is composed of state errors for 3 axes (roll, pitch, and yaw and a control signal for one of the 3 axes. The stability region of the ANFIS controller is estimated numerically based on Lyapunov stability theory using a numerical method to calculate Jacobian matrix. To measure the performance of the ANFIS controller, root mean square error and correlation factor are used as performance indicators. The performance is tested on two ANFIS controllers trained in different conditions. The test results show that the performance indicators are proper in the sense that the ANFIS controller with the larger stability region provides better performance according to the performance indicators.

  1. Model-based software engineering for an optical navigation system for spacecraft

    Science.gov (United States)

    Franz, T.; Lüdtke, D.; Maibaum, O.; Gerndt, A.

    2018-06-01

    The project Autonomous Terrain-based Optical Navigation (ATON) at the German Aerospace Center (DLR) is developing an optical navigation system for future landing missions on celestial bodies such as the moon or asteroids. Image data obtained by optical sensors can be used for autonomous determination of the spacecraft's position and attitude. Camera-in-the-loop experiments in the Testbed for Robotic Optical Navigation (TRON) laboratory and flight campaigns with unmanned aerial vehicle (UAV) are performed to gather flight data for further development and to test the system in a closed-loop scenario. The software modules are executed in the C++ Tasking Framework that provides the means to concurrently run the modules in separated tasks, send messages between tasks, and schedule task execution based on events. Since the project is developed in collaboration with several institutes in different domains at DLR, clearly defined and well-documented interfaces are necessary. Preventing misconceptions caused by differences between various development philosophies and standards turned out to be challenging. After the first development cycles with manual Interface Control Documents (ICD) and manual implementation of the complex interactions between modules, we switched to a model-based approach. The ATON model covers a graphical description of the modules, their parameters and communication patterns. Type and consistency checks on this formal level help to reduce errors in the system. The model enables the generation of interfaces and unified data types as well as their documentation. Furthermore, the C++ code for the exchange of data between the modules and the scheduling of the software tasks is created automatically. With this approach, changing the data flow in the system or adding additional components (e.g., a second camera) have become trivial.

  2. Model-based software engineering for an optical navigation system for spacecraft

    Science.gov (United States)

    Franz, T.; Lüdtke, D.; Maibaum, O.; Gerndt, A.

    2017-09-01

    The project Autonomous Terrain-based Optical Navigation (ATON) at the German Aerospace Center (DLR) is developing an optical navigation system for future landing missions on celestial bodies such as the moon or asteroids. Image data obtained by optical sensors can be used for autonomous determination of the spacecraft's position and attitude. Camera-in-the-loop experiments in the Testbed for Robotic Optical Navigation (TRON) laboratory and flight campaigns with unmanned aerial vehicle (UAV) are performed to gather flight data for further development and to test the system in a closed-loop scenario. The software modules are executed in the C++ Tasking Framework that provides the means to concurrently run the modules in separated tasks, send messages between tasks, and schedule task execution based on events. Since the project is developed in collaboration with several institutes in different domains at DLR, clearly defined and well-documented interfaces are necessary. Preventing misconceptions caused by differences between various development philosophies and standards turned out to be challenging. After the first development cycles with manual Interface Control Documents (ICD) and manual implementation of the complex interactions between modules, we switched to a model-based approach. The ATON model covers a graphical description of the modules, their parameters and communication patterns. Type and consistency checks on this formal level help to reduce errors in the system. The model enables the generation of interfaces and unified data types as well as their documentation. Furthermore, the C++ code for the exchange of data between the modules and the scheduling of the software tasks is created automatically. With this approach, changing the data flow in the system or adding additional components (e.g., a second camera) have become trivial.

  3. Thermal Protection System Mass Estimating Relationships For Blunt-Body, Earth Entry Spacecraft

    Science.gov (United States)

    Sepka, Steven A.; Samareh, Jamshid A.

    2015-01-01

    Mass estimating relationships (MERs) are developed to predict the amount of thermal protection system (TPS) necessary for safe Earth entry for blunt-body spacecraft using simple correlations that are non-ITAR and closely match estimates from NASA's highfidelity ablation modeling tool, the Fully Implicit Ablation and Thermal Analysis Program (FIAT). These MERs provide a first order estimate for rapid feasibility studies. There are 840 different trajectories considered in this study, and each TPS MER has a peak heating limit. MERs for the vehicle forebody include the ablators Phenolic Impregnated Carbon Ablator (PICA) and Carbon Phenolic atop Advanced Carbon-Carbon. For the aftbody, the materials are Silicone Impregnated Reusable Ceramic Ablator (SIRCA), Acusil II, SLA- 561V, and LI-900. The MERs are accurate to within 14% (at one standard deviation) of FIAT prediction, and the most any MER can under predict FIAT TPS thickness is 18.7%. This work focuses on the development of these MERs, the resulting equations, model limitations, and model accuracy.

  4. Proceedings: Small Wind Turbine Systems, 1981

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    Small wind turbine technology is discussed. Systems development, test programs, utility interface issues, safety and reliability programs, applications, and marketing are discussed. For individual titles, see N83-23723 through N83-23741.

  5. Origins of collectivity in small systems

    Science.gov (United States)

    Schenke, Björn

    2017-11-01

    We review recent developments in the theoretical description and understanding of multi-particle correlation measurements in collisions of small projectiles (p/d/3He) with heavy nuclei (Au, Pb) as well as proton+proton collisions. We focus on whether the physical processes responsible for the observed long range rapidity correlations and their azimuthal structure are the same in small systems as in heavy ion collisions. In the latter they are interpreted as generated by the initial spatial geometry being transformed into momentum correlations by strong final state interactions. However, explicit calculations show that also initial state momentum correlations are present and could contribute to observables in small systems. If strong final state interactions are present in small systems, recent developments show that results are sensitive to the shape of the proton and its fluctuations.

  6. FORMOSAT-3/COSMIC Spacecraft Constellation System, Mission Results, and Prospect for Follow-On Mission

    Directory of Open Access Journals (Sweden)

    Chen-Joe Fong

    2009-01-01

    Full Text Available The FORMOSAT-3/COSMIC spacecraft constellation consisting of six LEO satellites is the world's first operational GPS Radio Occultation (RO mission. The mission is jointly developed by Taiwan¡¦s National Space Organization (NSPO and the United States¡¦UCAR in collaboration with NSF, USAF, NOAA, NASA, NASA's Jet Propulsion Laboratory, and the US Naval Research Laboratory. The FORMOSAT-3/COSMIC satellites were successfully launched from Vandenberg US AFB in California at 0140 UTC 15 April 2006 into the same orbit plane of the designated 516 km altitude. The mission goal is to deploy the six satellites into six orbit planes at 800 km altitude with a 30-degree separation for evenly distributed global coverage. All six FORMOSAT-3/COSMIC satellites are currently maintaining a satisfactory good state-of-health. Five out of six satellites have reached their final mission orbit of 800 km as of November 2007. The data as received by FORMOSAT-3/COSMIC satellites constellation have been processed in near real time into 2500 good ionospheric profiles and 1800 good atmospheric profiles per day. These have outnumbered the worldwide radiosondes (~900 mostly over land launched from the ground per day. The processed atmospheric RO data have been assimilated into the Numerical Weather Prediction (NWP models for real-time weather prediction and typhoon/hurricane forecasting by many major weather centers in the world. This paper describes the FORMOSAT-3/COSMIC satellite constellation system performance and the mission results that span the period from April 2006 to October 2007; and reviews the prospect of a future follow-on mission.

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

    Science.gov (United States)

    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.

  8. Advanced Solar-propelled Cargo Spacecraft for Mars Missions

    Science.gov (United States)

    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).

  9. Event-triggered attitude control of spacecraft

    Science.gov (United States)

    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.

  10. Contributions of microgravity test results to the design of spacecraft fire-safety systems

    Science.gov (United States)

    Friedman, Robert; Urban, David L.

    1993-01-01

    Experiments conducted in spacecraft and drop towers show that thin-sheet materials have reduced flammability ranges and flame-spread rates under quiescent low-gravity environments (microgravity) compared to normal gravity. Furthermore, low-gravity flames may be suppressed more easily by atmospheric dilution or decreasing atmospheric total pressure than their normal-gravity counterparts. The addition of a ventilating air flow to the low-gravity flame zone, however, can greatly enhance the flammability range and flame spread. These results, along with observations of flame and smoke characteristics useful for microgravity fire-detection 'signatures', promise to be of considerable value to spacecraft fire-safety designs. The paper summarizes the fire detection and suppression techniques proposed for the Space Station Freedom and discusses both the application of low-gravity combustion knowledge to improve fire protection and the critical needs for further research.

  11. Contributions of Microgravity Test Results to the Design of Spacecraft Fire Safety Systems

    Science.gov (United States)

    Friedman, Robert; Urban, David L.

    1993-01-01

    Experiments conducted in spacecraft and drop towers show that thin-sheet materials have reduced flammability ranges and flame-spread rates under quiescent low-gravity environments (microgravity) as compared to normal gravity. Furthermore, low-gravity flames may be suppressed more easily by atmospheric dilution or decreasing atmospheric total pressure than their normal-gravity counterparts. The addition of a ventilating air flow to the low-gravity flame zone, however, can greatly enhance the flammability range and flame spread. These results, along with observations of flame and smoke characteristics useful for microgravity fire-detection 'signatures', promise to be of considerable value to spacecraft fire-safety designs. The paper summarizes the fire detection and suppression techniques proposed for the Space Station Freedom and discusses both the application of low-gravity combustion knowledge to improve fire protection and the critical needs for further research.

  12. Development of Star Tracker System for Accurate Estimation of Spacecraft Attitude

    Science.gov (United States)

    2009-12-01

    For a high- cost spacecraft with accurate pointing requirements, the use of a star tracker is the preferred method for attitude determination. The...solutions, however there are certain costs with using this algorithm. There are significantly more features a triangle can provide when compared to an...to the other. The non-rotating geocentric equatorial frame provides an inertial frame for the two-body problem of a satellite in orbit. In this

  13. SyZyGy: A straight interferometric spacecraft system for gravity wave observations

    International Nuclear Information System (INIS)

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

    2003-01-01

    We consider a spaceborne gravitational wave (GW) detector formed by three spacecraft in a linear array, coherently exchanging laser beams and using the data combinations of time-delay interferometry (TDI). We previously showed how the measured time series of Doppler shifts in the six one-way laser links between spacecraft pairs in a general unequal-arm triangular configuration can be combined, using TDI, to exactly cancel the otherwise overwhelming phase noise of the lasers while retaining sensitivity to GWs. Here we apply TDI, unfolding the general triangular configuration, to the special case of a linear array of three spacecraft. We show that such an array ('SyZyGy') has, compared with an equilateral triangle GW detector of the same scale, a degraded (but non-zero) sensitivity at low frequencies [f -4 -10 -1 Hz). SyZyGy with ∼1 light-second scale could, for the same instrumental assumptions as LISA, make observations in this intermediate frequency GW band with 5σ sensitivity to sinusoidal waves ≅2.5x10 -23 in a year's integration

  14. Degradation mechanisms of small scale piping systems

    International Nuclear Information System (INIS)

    Bartonicek, J.; Koenig, G.; Blind, D.

    1996-01-01

    Operational experience shows that many degradation mechanisms can have an effect on small-scale piping systems. We can see from the analyses carried out that the degradation which has occurred is primarily linked with the fact that these piping systems were classified as being of low safety relevance. This is mainly due to such components being classified into low safety relevance category at the design stage, as well as to the low level of operational monitoring. Since in spite of the variety of designs and operational modes the degradation mechanisms detected may be attributed to the piping systems, we can make decisive statements on how to avoid such degradation mechanisms. Even small-scale piping systems may achieve guaranteed integrity in such cases by taking the appropriate action. (orig.) [de

  15. A system for gathering small mammal data

    Science.gov (United States)

    Robert D. Neely; Robert W. Campbell

    1973-01-01

    As an aid to studying vertebrate predators of the gypsy moth, a radio telemetry system was designed to detect the death of small mammals and facilitate recovery of the remains. An intraperitoneally implanted radio transmitter is triggered by the drop in body temperature when the animal dies. The device was tested in white-footed mice.

  16. Practical Applications of Cosmic Ray Science: Spacecraft, Aircraft, Ground Based Computation and Control Systems and Human Health and Safety

    Science.gov (United States)

    Atwell, William; Koontz, Steve; Normand, Eugene

    2012-01-01

    In this paper we review the discovery of cosmic ray effects on the performance and reliability of microelectronic systems as well as on human health and safety, as well as the development of the engineering and health science tools used to evaluate and mitigate cosmic ray effects in earth surface, atmospheric flight, and space flight environments. Three twentieth century technological developments, 1) high altitude commercial and military aircraft; 2) manned and unmanned spacecraft; and 3) increasingly complex and sensitive solid state micro-electronics systems, have driven an ongoing evolution of basic cosmic ray science into a set of practical engineering tools (e.g. ground based test methods as well as high energy particle transport and reaction codes) needed to design, test, and verify the safety and reliability of modern complex electronic systems as well as effects on human health and safety. The effects of primary cosmic ray particles, and secondary particle showers produced by nuclear reactions with spacecraft materials, can determine the design and verification processes (as well as the total dollar cost) for manned and unmanned spacecraft avionics systems. Similar considerations apply to commercial and military aircraft operating at high latitudes and altitudes near the atmospheric Pfotzer maximum. Even ground based computational and controls systems can be negatively affected by secondary particle showers at the Earth's surface, especially if the net target area of the sensitive electronic system components is large. Accumulation of both primary cosmic ray and secondary cosmic ray induced particle shower radiation dose is an important health and safety consideration for commercial or military air crews operating at high altitude/latitude and is also one of the most important factors presently limiting manned space flight operations beyond low-Earth orbit (LEO).

  17. Dips spacecraft integration issues

    International Nuclear Information System (INIS)

    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

  18. Management system requirements for small reactors

    Energy Technology Data Exchange (ETDEWEB)

    Jones, K.A., E-mail: kenneth.jones@cnsc-ccsn.gc.ca [Canadian Nuclear Safety Commission, Ottawa, Ontario (Canada)

    2013-07-01

    This abstract identifies the management system requirements for the life cycle of small reactors from initial conception through completion of decommissioning. For small reactors, the requirements for management systems remain the same as those for 'large' reactors regardless of the licensee' business model and objectives. The CSA N-Series of standards provides an interlinked set of requirements for the management of nuclear facilities. CSA N286 provides overall direction to management to develop and implement sound management practices and controls, while other CSA nuclear standards provide technical requirements and guidance that support the management system. CSA N286 is based on a set of principles. The principles are then supported by generic requirements that are applicable to the life cycle of nuclear facilities. CNSC regulatory documents provide further technical requirements and guidance. (author)

  19. Manifold dynamics in the Earth-Moon system via isomorphic mapping with application to spacecraft end-of-life strategies

    Science.gov (United States)

    Pontani, Mauro; Giancotti, Marco; Teofilatto, Paolo

    2014-12-01

    Recently, manifold dynamics has assumed an increasing relevance for analysis and design of low-energy missions, both in the Earth-Moon system and in alternative multibody environments. With regard to lunar missions, exterior and interior transfers, based on the transit through the regions where the collinear libration points L1 and L2 are located, have been studied for a long time and some space missions have already taken advantage of the results of these studies. This paper is focused on the definition and use of a special isomorphic mapping for low-energy mission analysis. A convenient set of cylindrical coordinates is employed to describe the spacecraft dynamics (i.e. position and velocity), in the context of the circular restricted three-body problem, used to model the spacecraft motion in the Earth-Moon system. This isomorphic mapping of trajectories allows the identification and intuitive representation of periodic orbits and of the related invariant manifolds, which correspond to tubes that emanate from the curve associated with the periodic orbit. Heteroclinic connections, i.e. the trajectories that belong to both the stable and the unstable manifolds of two distinct periodic orbits, can be easily detected by means of this representation. This paper illustrates the use of isomorphic mapping for finding (a) periodic orbits, (b) heteroclinic connections between trajectories emanating from two Lyapunov orbits, the first at L1, and the second at L2, and (c) heteroclinic connections between trajectories emanating from the Lyapunov orbit at L1 and from a particular unstable lunar orbit. Heteroclinic trajectories are asymptotic trajectories that travels at zero-propellant cost. In practical situations, a modest delta-v budget is required to perform transfers along the manifolds. This circumstance implies the possibility of performing complex missions, by combining different types of trajectory arcs belonging to the manifolds. This work studies also the possible

  20. Thermal analysis of hybrid single-phase, two-phase and heat pump thermal control system (TCS) for future spacecraft

    International Nuclear Information System (INIS)

    Lee, S.H.; Mudawar, I.; Hasan, Mohammad M.

    2016-01-01

    Highlights: • Hybrid Thermal Control System (H-TCS) is proposed for future spacecraft. • Thermodynamic performance of H-TCS is examined for different space missions. • Operational modes including single-phase, two-phase and heat pump are explored. • R134a is deemed most appropriate working fluid. - Abstract: An urgent need presently exists to develop a new class of versatile spacecraft capable of conducting different types of missions and enduring varying gravitational and temperature environments, including Lunar, Martian and Near Earth Object (NEOs). This study concerns the spacecraft's Thermal Control System (TCS), which tackles heat acquisition, especially from crew and avionics, heat transport, and ultimate heat rejection by radiation. The primary goal of the study is to explore the design and thermal performance of a Hybrid Thermal Control System (H-TCS) that would satisfy the diverse thermal requirements of the different space missions. The H-TCS must endure both ‘cold’ and ‘hot’ environments, reduce weight and size, and enhance thermodynamic performance. Four different operational modes are considered: single-phase, two-phase, basic heat pump and heat pump with liquid-side, suction-side heat exchanger. A thermodynamic trade study is conducted for six different working fluids to assess important performance parameters including mass flow rate of the working fluid, maximum pressure, radiator area, compressor/pump work, and coefficient of performance (COP). R134a is determined to be most suitable based on its ability to provide a balanced compromise between reducing flow rate and maintaining low system pressure, and a moderate coefficient of performance (COP); this fluid is also both nontoxic and nonflammable, and features zero ozone depletion potential (ODP) and low global warming potential (GWP). It is shown how specific mission stages dictate which mode of operation is most suitable, and this information is used to size the radiator for the

  1. Revamping Spacecraft Operational Intelligence

    Science.gov (United States)

    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.

  2. Microencapsulated PCM slurries for heat transfer and energy storage in spacecraft systems

    Science.gov (United States)

    Colvin, David P.; Mulligan, James C.; Bryant, Yvonne G.; Duncan, John L.; Gravely, Benjamin T.

    1992-01-01

    The technical feasibility for providing significantly enhanced heat transport and storage as well as improved thermal control has been investigated during several Small Business Innovative Research (SBIR) programs for NASA, the United States Air Force (USAF), and the Strategic Defense Initiative Organization (SDIO) using microencapsulated phase change materials (PCMs) in both aqueous and nonaqueous two-component slurries. In the program for SDIO, novel two-component coolant fluids were prepared and successfully tested at both low (300 K) and intermediate temperatures (460 to 700 K). The two-component fluid slurries of microencapsulated PCMs included organic particles in aqueous and nonaqueous liquids, as well as microencapsulated metals that potentially could be carried by liquid metals or used as powdered heat sinks. Simulation and experimental studies showed that such active cooling systems could be designed and operated with enhancements of heat capacity that exceeded 10 times or 1000 percent that for the base fluid along with significant enhancement in the fluid's heat capacity. Furthermore, this enhancement provided essentially isothermal conditions throughout the pumped primary coolant fluid loop. The results suggest that together with much higher fluid thermal capacity, greater uniformity of temperature is achievable with such fluids, and that significant reductions in pumping power, system size, and system mass are also possible.

  3. Correlations in small systems with ALICE

    CERN Document Server

    Lakomov, Igor

    2016-01-01

    ALICE is dedicated to the study of the strongly interacting matter, the so-called Quark-Gluon Plasma (QGP), formed in heavy-ion collisions at the LHC. In addition, ALICE also actively participated in the pp and p–Pb collision programs. In particular, the measurements of the twoparticle azimuthal correlations in pp collisions at √ s = 7 TeV and in p–Pb collisions at √ sNN = 5.02 TeV have been performed by the ALICE Collaboration during Run I of the LHC. Similar long-range correlations in p–Pb and Pb–Pb collisions have been observed on the near and away side — also known as the double ridge. Further investigations showed the importance of the Multi-Parton Interactions (MPI) in high-multiplicity collisions in small systems. In this work the ALICE results on the correlations in small systems are presented including MPI measurements in pp collisions.

  4. In-orbit evaluation of the control system/structural mode interactions of the OSO-8 spacecraft

    Science.gov (United States)

    Slafer, L. I.

    1979-01-01

    The Orbiting Solar Observatory-8 experienced severe structural mode/control loop interaction problems during the spacecraft development. Extensive analytical studies, using the hybrid coordinate modeling approach, and comprehensive ground testing were carried out in order to achieve the system's precision pointing performance requirements. A recent series of flight tests were conducted with the spacecraft in which a wide bandwidth, high resolution telemetry system was utilized to evaluate the on-orbit flexible dynamics characteristics of the vehicle along with the control system performance. The paper describes the results of these tests, reviewing the basic design problem, analytical approach taken, ground test philosophy, and on-orbit testing. Data from the tests was used to determine the primary mode frequency, damping, and servo coupling dynamics for the on-orbit condition. Additionally, the test results have verified analytically predicted differences between the on-orbit and ground test environments, and have led to a validation of both the analytical modeling and servo design techniques used during the development of the control system.

  5. Performance analysis of a GPS Interferometric attitude determination system for a gravity gradient stabilized spacecraft. M.S. Thesis

    Science.gov (United States)

    Stoll, John C.

    1995-01-01

    The performance of an unaided attitude determination system based on GPS interferometry is examined using linear covariance analysis. The modelled system includes four GPS antennae onboard a gravity gradient stabilized spacecraft, specifically the Air Force's RADCAL satellite. The principal error sources are identified and modelled. The optimal system's sensitivities to these error sources are examined through an error budget and by varying system parameters. The effects of two satellite selection algorithms, Geometric and Attitude Dilution of Precision (GDOP and ADOP, respectively) are examined. The attitude performance of two optimal-suboptimal filters is also presented. Based on this analysis, the limiting factors in attitude accuracy are the knowledge of the relative antenna locations, the electrical path lengths from the antennae to the receiver, and the multipath environment. The performance of the system is found to be fairly insensitive to torque errors, orbital inclination, and the two satellite geometry figures-of-merit tested.

  6. Spacecraft operations

    CERN Document Server

    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).

  7. Internet Technology on Spacecraft

    Science.gov (United States)

    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

  8. A passively controlled appendage deployment system for the San Marco D/L spacecraft

    Science.gov (United States)

    Lang, W. E.; Frisch, H. P.; Schwartz, D. A.

    1984-01-01

    The analytical simulation of deployment dynamics of these two axis concepts as well as the evolution of practical designs for the add on deployable inertia boom units is described. With the boom free to swing back in response to Coriolis forces as well as outwards in response to centrifugal forces, the kinematics of motion are complex but admit the possibility of absorbing deployment energy in frictional or other damping devices about the radial axis, where large amplitude motions can occur and where the design envelope allows more available volume. An acceptable range is defined for frictional damping for any given spin rate. Inadequate damping allows boom motions which strike the spacecraft; excessive damping causes the boom to swing out and latch with damaging violence. The acceptable range is a design parameter and must accommodate spin rate tolerance and also the tolerance and repeatability of the damping mechanisms.

  9. Advances in Small Animal Imaging Systems

    International Nuclear Information System (INIS)

    Loudos, George K.

    2007-01-01

    The rapid growth in genetics and molecular biology combined with the development of techniques for genetically engineering small animals has led to an increased interest in in vivo laboratory animal imaging during the past few years. For this purpose, new instrumentation, data acquisition strategies, and image processing and reconstruction techniques are being developed, researched and evaluated. The aim of this article is to give a short overview of the state of the art technologies for high resolution and high sensitivity molecular imaging techniques, primarily positron emission tomography (PET) and single photon emission computed tomography (SPECT). The basic needs of small animal imaging will be described. The evolution in instrumentation in the past two decades, as well as the commercially available systems will be overviewed. Finally, the new trends in detector technology and preliminary results from challenging applications will be presented. For more details a number of references are provided

  10. Observing System Simulations for Small Satellite Formations Estimating Bidirectional Reflectance

    Science.gov (United States)

    Nag, Sreeja; Gatebe, Charles K.; de Weck, Olivier

    2015-01-01

    The bidirectional reflectance distribution function (BRDF) gives the reflectance of a target as a function of illumination geometry and viewing geometry, hence carries information about the anisotropy of the surface. BRDF is needed in remote sensing for the correction of view and illumination angle effects (for example in image standardization and mosaicing), for deriving albedo, for land cover classification, for cloud detection, for atmospheric correction, and other applications. However, current spaceborne instruments provide sparse angular sampling of BRDF and airborne instruments are limited in the spatial and temporal coverage. To fill the gaps in angular coverage within spatial, spectral and temporal requirements, we propose a new measurement technique: Use of small satellites in formation flight, each satellite with a VNIR (visible and near infrared) imaging spectrometer, to make multi-spectral, near-simultaneous measurements of every ground spot in the swath at multiple angles. This paper describes an observing system simulation experiment (OSSE) to evaluate the proposed concept and select the optimal formation architecture that minimizes BRDF uncertainties. The variables of the OSSE are identified; number of satellites, measurement spread in the view zenith and relative azimuth with respect to solar plane, solar zenith angle, BRDF models and wavelength of reflection. Analyzing the sensitivity of BRDF estimation errors to the variables allow simplification of the OSSE, to enable its use to rapidly evaluate formation architectures. A 6-satellite formation is shown to produce lower BRDF estimation errors, purely in terms of angular sampling as evaluated by the OSSE, than a single spacecraft with 9 forward-aft sensors. We demonstrate the ability to use OSSEs to design small satellite formations as complements to flagship mission data. The formations can fill angular sampling gaps and enable better BRDF products than currently possible.

  11. Observing system simulations for small satellite formations estimating bidirectional reflectance

    Science.gov (United States)

    Nag, Sreeja; Gatebe, Charles K.; Weck, Olivier de

    2015-12-01

    The bidirectional reflectance distribution function (BRDF) gives the reflectance of a target as a function of illumination geometry and viewing geometry, hence carries information about the anisotropy of the surface. BRDF is needed in remote sensing for the correction of view and illumination angle effects (for example in image standardization and mosaicing), for deriving albedo, for land cover classification, for cloud detection, for atmospheric correction, and other applications. However, current spaceborne instruments provide sparse angular sampling of BRDF and airborne instruments are limited in the spatial and temporal coverage. To fill the gaps in angular coverage within spatial, spectral and temporal requirements, we propose a new measurement technique: use of small satellites in formation flight, each satellite with a VNIR (visible and near infrared) imaging spectrometer, to make multi-spectral, near-simultaneous measurements of every ground spot in the swath at multiple angles. This paper describes an observing system simulation experiment (OSSE) to evaluate the proposed concept and select the optimal formation architecture that minimizes BRDF uncertainties. The variables of the OSSE are identified; number of satellites, measurement spread in the view zenith and relative azimuth with respect to solar plane, solar zenith angle, BRDF models and wavelength of reflection. Analyzing the sensitivity of BRDF estimation errors to the variables allow simplification of the OSSE, to enable its use to rapidly evaluate formation architectures. A 6-satellite formation is shown to produce lower BRDF estimation errors, purely in terms of angular sampling as evaluated by the OSSE, than a single spacecraft with 9 forward-aft sensors. We demonstrate the ability to use OSSEs to design small satellite formations as complements to flagship mission data. The formations can fill angular sampling gaps and enable better BRDF products than currently possible.

  12. Modified quantum mechanics of small composite systems

    International Nuclear Information System (INIS)

    Wolters, G.F.

    1986-12-01

    Boundary conditions on radial wave functions are considered for a particle bound by a central potential. It is argued that the usual condition at the origin needs modification for systems of small intrinsic size. This affects s-states, especially the ground state. With the obtained modification the virial theorem is imposed rather than derived. As an illustration the central rectangular well potential is treated and applied to the nucleon. Its soft electromagnetic structure can be largely explained while quark confinement holds despite moderate strength of the potential. A discussion follows. (Auth.)

  13. Refueling system with small diameter rotatable plugs

    International Nuclear Information System (INIS)

    Ritz, W.C.

    1987-01-01

    This patent describes a liquid-metal fastbreeder nuclear reactor comprising a reactor pressure vessel and closure head therefor, a reactor core barrel disposed within the reactor vessel and enclosing a reactor core having therein a large number of closely spaced fuel assemblies, and the reactor core barrel and the reactor core having an approximately concentric circular cross-sectional configuration with a geometric center in predetermined location within the reactor vessel. The improved refueling system described here comprises: a large controllably rotatable plug means comprising the substantial portion of the closure head, a reactor upper internals structure mounted from the large rotatable plug means. The large rotatable plug means has an approximately circular configuration which approximates the cross-sectional configuration of the reactor core barrel with a center of rotation positioned a first predetermined distance from the geometric center of the reactor core barrel so that the large rotatable plug means rotates eccentrically with respect to the reactor core barrel; a small controllably rotatable plug means affixed to the large rotatable plug means and rotatable with respect thereto. The small rotatable plug means has a center of rotation which is offset a second predetermined distance from the rotational center of the large rotatable plug means so that the small rotatable plug means rotates eccentrically with respect to the large rotatable plug means

  14. Systems Pharmacology in Small Molecular Drug Discovery

    Directory of Open Access Journals (Sweden)

    Wei Zhou

    2016-02-01

    Full Text Available Drug discovery is a risky, costly and time-consuming process depending on multidisciplinary methods to create safe and effective medicines. Although considerable progress has been made by high-throughput screening methods in drug design, the cost of developing contemporary approved drugs did not match that in the past decade. The major reason is the late-stage clinical failures in Phases II and III because of the complicated interactions between drug-specific, human body and environmental aspects affecting the safety and efficacy of a drug. There is a growing hope that systems-level consideration may provide a new perspective to overcome such current difficulties of drug discovery and development. The systems pharmacology method emerged as a holistic approach and has attracted more and more attention recently. The applications of systems pharmacology not only provide the pharmacodynamic evaluation and target identification of drug molecules, but also give a systems-level of understanding the interaction mechanism between drugs and complex disease. Therefore, the present review is an attempt to introduce how holistic systems pharmacology that integrated in silico ADME/T (i.e., absorption, distribution, metabolism, excretion and toxicity, target fishing and network pharmacology facilitates the discovery of small molecular drugs at the system level.

  15. Optical Property Requirements for Glasses, Ceramics and Plastics in Spacecraft Window Systems

    Science.gov (United States)

    Estes, Lynda

    2011-01-01

    This is a preliminary draft of a standard published by the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) that is intended to provide uniform window optical design requirements in support of the development of human-rated spaceflight hardware. The material covered in this standard is based on data from extensive testing by the Advanced Sensing and Optical Measurement Branch at NASA Langley Research Center, and compiled into requirements format by the NASA JSC Structural Engineering Division. At the time of this initial document release, a broader technical community has not reviewed this standard. The technical content of this standard is primarily based on the Constellation Program Orion Crew Exploration Vehicle Window Optical Properties Requirements, CxP 72407, Baseline. Unlike other optical requirements documents available for human rated spacecraft, this document includes requirements that ensure functionality for windows that contain glass/ceramic and/or plastic window substrate materials. These requirements were derived by measuring the optical properties of fused silica and aluminosilicate glass window assemblies and ensuring that the performance of any window assembly that includes a plastic pane or panes will meet the performance level of the all-glass assemblies. The resulting requirements are based upon the performance and parameter metrology testing of a variety of materials, including glass, transparent ceramics, acrylics, and polycarbonates. In general, these requirements are minimum specifications for each optical parameter in order to achieve the function specified for each functional category, A through D. Because acrylic materials perform at a higher level than polycarbonates in the optics regime, and CxP/Orion is planning to use acrylic in the Orion spacecraft, these requirements are based heavily on metrology from that material. As a result, two of the current Category D requirements for plastics are cited in

  16. Small business innovation research. Abstracts of completed 1987 phase 1 projects

    Science.gov (United States)

    1989-01-01

    Non-proprietary summaries of Phase 1 Small Business Innovation Research (SBIR) projects supported by NASA in the 1987 program year are given. Work in the areas of aeronautical propulsion, aerodynamics, acoustics, aircraft systems, materials and structures, teleoperators and robotics, computer sciences, information systems, spacecraft systems, spacecraft power supplies, spacecraft propulsion, bioastronautics, satellite communication, and space processing are covered.

  17. Mesh Network Architecture for Enabling Inter-Spacecraft Communication

    Science.gov (United States)

    Becker, Christopher; Merrill, Garrick

    2017-01-01

    To enable communication between spacecraft operating in a formation or small constellation, a mesh network architecture was developed and tested using a time division multiple access (TDMA) communication scheme. The network is designed to allow for the exchange of telemetry and other data between spacecraft to enable collaboration between small spacecraft. The system uses a peer-to-peer topology with no central router, so that it does not have a single point of failure. The mesh network is dynamically configurable to allow for addition and subtraction of new spacecraft into the communication network. Flight testing was performed using an unmanned aerial system (UAS) formation acting as a spacecraft analogue and providing a stressing environment to prove mesh network performance. The mesh network was primarily devised to provide low latency, high frequency communication but is flexible and can also be configured to provide higher bandwidth for applications desiring high data throughput. The network includes a relay functionality that extends the maximum range between spacecraft in the network by relaying data from node to node. The mesh network control is implemented completely in software making it hardware agnostic, thereby allowing it to function with a wide variety of existing radios and computing platforms..

  18. Performance verification and system parameter identification of spacecraft tape recorder control servo

    Science.gov (United States)

    Mukhopadhyay, A. K.

    1979-01-01

    Design adequacy of the lead-lag compensator of the frequency loop, accuracy checking of the analytical expression for the electrical motor transfer function, and performance evaluation of the speed control servo of the digital tape recorder used on-board the 1976 Viking Mars Orbiters and Voyager 1977 Jupiter-Saturn flyby spacecraft are analyzed. The transfer functions of the most important parts of a simplified frequency loop used for test simulation are described and ten simulation cases are reported. The first four of these cases illustrate the method of selecting the most suitable transfer function for the hysteresis synchronous motor, while the rest verify and determine the servo performance parameters and alternative servo compensation schemes. It is concluded that the linear methods provide a starting point for the final verification/refinement of servo design by nonlinear time response simulation and that the variation of the parameters of the static/dynamic Coulomb friction is as expected in a long-life space mission environment.

  19. Development of Low-Toxicity Wastewater Stabilization for Spacecraft Water Recovery Systems

    Science.gov (United States)

    Adam, Niklas; Mitchell, Julie; Pickering, Karen; Carrier, Chris; Vega, Letty; Muirhead, Dean

    2014-01-01

    Wastewater stabilization was an essential component of the spacecraft water cycle. The purpose of stabilizing wastewater was two-fold. First, stabilization prevents the breakdown of urea into ammonia, a toxic gas at high concentrations. Second, it prevents the growth of microorganisms, thereby mitigating hardware and water quality issues due to due biofilm and planktonic growth. Current stabilization techniques involve oxidizers and strong acids (pH=2) such as chromic and sulfuric acid, which are highly toxic and pose a risk to crew health. The purpose of this effort was to explore less toxic stabilization techniques, such as food-grade and commercial care preservatives. Additionally, certain preservatives were tested in the presence of a low-toxicity organic acid. Triplicate 300-mL volumes of urine were dosed with a predetermined quantity of stabilizer and stored for two weeks. During that time, pH, total organic carbon (TOC), ammonia, and turbidity were monitored. Those preservatives that showed the lowest visible microbial growth and stable pH were further tested in a six-month stability study. The results of the six-month study are also included in this paper.

  20. Project-based learning applied to spacecraft power systems: a long-term engineering and educational program at UPM University

    Science.gov (United States)

    Pindado, Santiago; Cubas, Javier; Roibás-Millán, Elena; Sorribes-Palmer, Félix

    2018-03-01

    The IDR/UPM Institute is the research center responsible for the Master in Space Systems (MUSE) of Universidad Politécnica de Madrid (UPM). This is a 2-year (120 ECTS) master's degree focused on space technology. The UPMSat-2 satellite program has become an excellent educational framework in which the academic contents of the master are trained through project-based learning and following a multidisciplinary approach. In the present work, the educational projects developed and carried out in relation to spacecraft power systems at the IDR/UPM Institute are described. These projects are currently being developed in the framework represented by the aforementioned MUSE master's program and UPMSat-2.

  1. Innovative High Temperature Heat Pipes for Spacecraft Nuclear Fission Systems, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA Glenn is examining small fission reactors for future space transportation and surface power applications. The reactors would have an 8 to 15 year design life...

  2. Developing Large-Scale Bayesian Networks by Composition: Fault Diagnosis of Electrical Power Systems in Aircraft and Spacecraft

    Science.gov (United States)

    Mengshoel, Ole Jakob; Poll, Scott; Kurtoglu, Tolga

    2009-01-01

    In this paper, we investigate the use of Bayesian networks to construct large-scale diagnostic systems. In particular, we consider the development of large-scale Bayesian networks by composition. This compositional approach reflects how (often redundant) subsystems are architected to form systems such as electrical power systems. We develop high-level specifications, Bayesian networks, clique trees, and arithmetic circuits representing 24 different electrical power systems. The largest among these 24 Bayesian networks contains over 1,000 random variables. Another BN represents the real-world electrical power system ADAPT, which is representative of electrical power systems deployed in aerospace vehicles. In addition to demonstrating the scalability of the compositional approach, we briefly report on experimental results from the diagnostic competition DXC, where the ProADAPT team, using techniques discussed here, obtained the highest scores in both Tier 1 (among 9 international competitors) and Tier 2 (among 6 international competitors) of the industrial track. While we consider diagnosis of power systems specifically, we believe this work is relevant to other system health management problems, in particular in dependable systems such as aircraft and spacecraft. (See CASI ID 20100021910 for supplemental data disk.)

  3. How Spacecraft Fly Spaceflight Without Formulae

    CERN Document Server

    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 ...

  4. DET/MPS - THE GSFC ENERGY BALANCE PROGRAM, DIRECT ENERGY TRANSFER/MULTIMISSION SPACECRAFT MODULAR POWER SYSTEM (UNIX VERSION)

    Science.gov (United States)

    Jagielski, J. M.

    1994-01-01

    The DET/MPS programs model and simulate the Direct Energy Transfer and Multimission Spacecraft Modular Power System in order to aid both in design and in analysis of orbital energy balance. Typically, the DET power system has the solar array directly to the spacecraft bus, and the central building block of MPS is the Standard Power Regulator Unit. DET/MPS allows a minute-by-minute simulation of the power system's performance as it responds to various orbital parameters, focusing its output on solar array output and battery characteristics. While this package is limited in terms of orbital mechanics, it is sufficient to calculate eclipse and solar array data for circular or non-circular orbits. DET/MPS can be adjusted to run one or sequential orbits up to about one week, simulated time. These programs have been used on a variety of Goddard Space Flight Center spacecraft projects. DET/MPS is written in FORTRAN 77 with some VAX-type extensions. Any FORTRAN 77 compiler that includes VAX extensions should be able to compile and run the program with little or no modifications. The compiler must at least support free-form (or tab-delineated) source format and 'do do-while end-do' control structures. DET/MPS is available for three platforms: GSC-13374, for DEC VAX series computers running VMS, is available in DEC VAX Backup format on a 9-track 1600 BPI tape (standard distribution) or TK50 tape cartridge; GSC-13443, for UNIX-based computers, is available on a .25 inch streaming magnetic tape cartridge in UNIX tar format; and GSC-13444, for Macintosh computers running AU/X with either the NKR FORTRAN or AbSoft MacFORTRAN II compilers, is available on a 3.5 inch 800K Macintosh format diskette. Source code and test data are supplied. The UNIX version of DET requires 90K of main memory for execution. DET/MPS was developed in 1990. A/UX and Macintosh are registered trademarks of Apple Computer, Inc. VMS, DEC VAX and TK50 are trademarks of Digital Equipment Corporation. UNIX is a

  5. Information Service System For Small Forestowners

    Science.gov (United States)

    Zhang, Shaochen; Li, Yun

    Individual owned forests have boomed in the last decade in China. Hundreds of millions of private forest owners have emerged since years of afforestation practice and collective forest ownership reform. Most of those private forest owners are former peasants living in afforestation areas. They thirst for forestry information, such as technique knowledge, forestry policies, finance, marketing, etc. Unfortunately the ways they could get certain information are very limit. Before internet time, Local governments are the main channel they search helps for useful information and technique supports. State and local governments have paid much attention to provide necessary forestry technique supports to those small forest owners and provided varies training projects, issued official forestry information through their websites. While, as state government expands household contract system in the management of collective forestry land, the number of individual forest owners is bumping up in future 5 years. There is still a gap between supplying ability and requirement of forestry information. To construct an effective forestry information service system in next 3-5 year can bridge the gap. This paper discusses the framework of such an information service system.

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

    National Research Council Canada - National Science Library

    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...

  7. Practical Applications of Cosmic Ray Science: Spacecraft, Aircraft, Ground-Based Computation and Control Systems, and Human Health and Safety

    Science.gov (United States)

    Atwell, William; Koontz, Steve; Normand, Eugene

    2012-01-01

    Three twentieth century technological developments, 1) high altitude commercial and military aircraft; 2) manned and unmanned spacecraft; and 3) increasingly complex and sensitive solid state micro-electronics systems, have driven an ongoing evolution of basic cosmic ray science into a set of practical engineering tools needed to design, test, and verify the safety and reliability of modern complex technological systems. The effects of primary cosmic ray particles and secondary particle showers produced by nuclear reactions with the atmosphere, can determine the design and verification processes (as well as the total dollar cost) for manned and unmanned spacecraft avionics systems. Similar considerations apply to commercial and military aircraft operating at high latitudes and altitudes near the atmospheric Pfotzer maximum. Even ground based computational and controls systems can be negatively affected by secondary particle showers at the Earth s surface, especially if the net target area of the sensitive electronic system components is large. Finally, accumulation of both primary cosmic ray and secondary cosmic ray induced particle shower radiation dose is an important health and safety consideration for commercial or military air crews operating at high altitude/latitude and is also one of the most important factors presently limiting manned space flight operations beyond low-Earth orbit (LEO). In this paper we review the discovery of cosmic ray effects on the performance and reliability of microelectronic systems as well as human health and the development of the engineering and health science tools used to evaluate and mitigate cosmic ray effects in ground-based atmospheric flight, and space flight environments. Ground test methods applied to microelectronic components and systems are used in combinations with radiation transport and reaction codes to predict the performance of microelectronic systems in their operating environments. Similar radiation transport

  8. Low-cost gossamer systems for solar sailing and spacecraft deorbiting applications.

    OpenAIRE

    Fernandez, Juan M.

    2015-01-01

    Nowadays, a technology demonstrator platform popular amongst the research community given their relatively low cost and short development time are cubesats. Nevertheless, cubesats are by definition nano-satellites of small volume and mass, and therefore, they traditionally only allowed very limited sizes of any expandable structure onboard with final deployed areas in the order of a few square meters. This conflicts with the large areas required for efficient solar sails, making the demonstra...

  9. Experimental overview on small collision systems at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Loizides, Constantin

    2016-12-15

    These conferences proceedings summarize the experimental findings obtained in small collision systems at the LHC, as presented in the special session on “QGP in small systems?” at the Quark Matter 2015 conference.

  10. Acceptance of enterprise resource planning systems by small manufacturing enterprises

    CSIR Research Space (South Africa)

    Adam, R

    2011-06-01

    Full Text Available systems by small enterprises. This paper addresses this gap by considering the strategic, business, technical and human factors that influence the acceptance of ERP systems in small manufacturing enterprises in South Africa. The consultative list...

  11. Vapor Compression Refrigeration System for Cold Storage on Spacecrafts, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA is looking for a high efficiency long term food storage system for space crafts. Previous refrigerator/freezer systems developed for this application such as...

  12. Multi-Component Remediation System for Generating Potable Water Onboard Spacecrafts, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Fractal Systems Inc. proposes to develop an innovative, energy-efficient water purification system to enable humans to live and work permanently in space. Water...

  13. Hydrothermal systems in small ocean planets.

    Science.gov (United States)

    Vance, Steve; Harnmeijer, Jelte; Kimura, Jun; Hussmann, Hauke; Demartin, Brian; Brown, J Michael

    2007-12-01

    We examine means for driving hydrothermal activity in extraterrestrial oceans on planets and satellites of less than one Earth mass, with implications for sustaining a low level of biological activity over geological timescales. Assuming ocean planets have olivine-dominated lithospheres, a model for cooling-induced thermal cracking shows how variation in planet size and internal thermal energy may drive variation in the dominant type of hydrothermal system-for example, high or low temperature system or chemically driven system. As radiogenic heating diminishes over time, progressive exposure of new rock continues to the current epoch. Where fluid-rock interactions propagate slowly into a deep brittle layer, thermal energy from serpentinization may be the primary cause of hydrothermal activity in small ocean planets. We show that the time-varying hydrostatic head of a tidally forced ice shell may drive hydrothermal fluid flow through the seafloor, which can generate moderate but potentially important heat through viscous interaction with the matrix of porous seafloor rock. Considering all presently known potential ocean planets-Mars, a number of icy satellites, Pluto, and other trans-neptunian objects-and applying Earth-like material properties and cooling rates, we find depths of circulation are more than an order of magnitude greater than in Earth. In Europa and Enceladus, tidal flexing may drive hydrothermal circulation and, in Europa, may generate heat on the same order as present-day radiogenic heat flux at Earth's surface. In all objects, progressive serpentinization generates heat on a globally averaged basis at a fraction of a percent of present-day radiogenic heating and hydrogen is produced at rates between 10(9) and 10(10) molecules cm(2) s(1).

  14. Passive radiative cooling of a HTS coil for attitude orbit control in micro-spacecraft

    Science.gov (United States)

    Inamori, Takaya; Ozaki, Naoya; Saisutjarit, Phongsatorn; Ohsaki, Hiroyuki

    2015-02-01

    This paper proposes a novel radiative cooling system for a high temperature superconducting (HTS) coil for an attitude orbit control system in nano- and micro-spacecraft missions. These days, nano-spacecraft (1-10 kg) and micro-spacecraft (10-100 kg) provide space access to a broader range of spacecraft developers and attract interest as space development applications. In planetary and high earth orbits, most previous standard-size spacecraft used thrusters for their attitude and orbit control, which are not available for nano- and micro-spacecraft missions because of the strict power consumption, space, and weight constraints. This paper considers orbit and attitude control methods that use a superconducting coil, which interacts with on-orbit space plasmas and creates a propulsion force. Because these spacecraft cannot use an active cooling system for the superconducting coil because of their mass and power consumption constraints, this paper proposes the utilization of a passive radiative cooling system, in which the superconducting coil is thermally connected to the 3 K cosmic background radiation of deep space, insulated from the heat generation using magnetic holders, and shielded from the sun. With this proposed cooling system, the HTS coil is cooled to 60 K in interplanetary orbits. Because the system does not use refrigerators for its cooling system, the spacecraft can achieve an HTS coil with low power consumption, small mass, and low cost.

  15. Spacecraft Environmental Interactions Technology, 1983

    Science.gov (United States)

    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.

  16. Pressure-Fed LOX/LCH4 Reaction Control System for Spacecraft: Transient Modeling and Thermal Vacuum Hotfire Test Results

    Science.gov (United States)

    Atwell, Matthew J.; Hurlbert, Eric A.; Melcher, J. C.; Morehead, Robert L.

    2017-01-01

    An integrated cryogenic liquid oxygen, liquid methane (LOX/LCH4) reaction control system (RCS) was tested at NASA Glenn Research Center's Plum Brook Station in the Spacecraft Propulsion Research Facility (B-2) under vacuum and thermal vacuum conditions. The RCS is a subsystem of the Integrated Cryogenic Propulsion Test Article (ICPTA), a pressure-fed LOX/LCH4 propulsion system composed of a single 2,800 lbf main engine, two 28 lbf RCS engines, and two 7 lbf RCS engines. Propellants are stored in four 48 inch diameter 5083 aluminum tanks that feed both the main engine and RCS engines in parallel. Helium stored cryogenically in a composite overwrapped pressure vessel (COPV) flows through a heat exchanger on the main engine before being used to pressurize the propellant tanks to a design operating pressure of 325 psi. The ICPTA is capable of simultaneous main engine and RCS operation. The RCS engines utilize a coil-on-plug (COP) ignition system designed for operation in a vacuum environment, eliminating corona discharge issues associated with a high voltage lead. There are two RCS pods on the ICPTA, with two engines on each pod. One of these two engines is a heritage flight engine from Project Morpheus. Its sea level nozzle was removed and replaced by an 85:1 nozzle machined using Inconel 718, resulting in a maximum thrust of 28 lbf under altitude conditions. The other engine is a scaled down version of the 28 lbf engine, designed to match the core and overall mixture ratios as well as other injector characteristics. This engine can produce a maximum thrust of 7 lbf with an 85:1 nozzle that was additively manufactured using Inconel 718. Both engines are film-cooled and capable of limited duration gas-gas and gas-liquid operation, as well as steady-state liquid-liquid operation. Each pod contains one of each version, such that two engines of the same thrust level can be fired as a couple on opposite pods. The RCS feed system is composed of symmetrical 3/8 inch lines

  17. Spacecraft Thermal Management

    Science.gov (United States)

    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

  18. The State of Play US Space Systems Competitiveness: Prices, Productivity, and Other Measures of Launchers & Spacecraft

    Science.gov (United States)

    Zapata, Edgar

    2017-01-01

    Collects space systems cost and related data (flight rate, payload, etc.) over time. Gathers only public data. Non-recurring and recurring. Minimal data processing. Graph, visualize, add context. Focus on US space systems competitiveness. Keep fresh update as data arises, launches occur, etc. Keep fresh focus on recent data, indicative of the future.

  19. Common data buffer system. [communication with computational equipment utilized in spacecraft operations

    Science.gov (United States)

    Byrne, F. (Inventor)

    1981-01-01

    A high speed common data buffer system is described for providing an interface and communications medium between a plurality of computers utilized in a distributed computer complex forming part of a checkout, command and control system for space vehicles and associated ground support equipment. The system includes the capability for temporarily storing data to be transferred between computers, for transferring a plurality of interrupts between computers, for monitoring and recording these transfers, and for correcting errors incurred in these transfers. Validity checks are made on each transfer and appropriate error notification is given to the computer associated with that transfer.

  20. Reliability considerations in long-life outer planet spacecraft system design

    Science.gov (United States)

    Casani, E. K.

    1975-01-01

    A Mariner Jupiter/Saturn mission has been planned for 1977. System reliability questions are discussed, taking into account the actual and design lifetime, causes of mission termination, in-flight failures and their consequences for the mission, and the use of redundancy to avoid failures. The design process employed optimizes the use of proven subsystem and system designs and then makes the necessary improvements to increase the lifetime as required.

  1. Delivering spacecraft control centers with embedded knowledge-based systems: The methodology issue

    Science.gov (United States)

    Ayache, S.; Haziza, M.; Cayrac, D.

    1994-01-01

    Matra Marconi Space (MMS) occupies a leading place in Europe in the domain of satellite and space data processing systems. The maturity of the knowledge-based systems (KBS) technology, the theoretical and practical experience acquired in the development of prototype, pre-operational and operational applications, make it possible today to consider the wide operational deployment of KBS's in space applications. In this perspective, MMS has to prepare the introduction of the new methods and support tools that will form the basis of the development of such systems. This paper introduces elements of the MMS methodology initiatives in the domain and the main rationale that motivated the approach. These initiatives develop along two main axes: knowledge engineering methods and tools, and a hybrid method approach for coexisting knowledge-based and conventional developments.

  2. Large Scale Experiments on Spacecraft Fire Safety

    DEFF Research Database (Denmark)

    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. Development of Mission and Spacecraft Dynamics Analysis System for Geostationary Communication Satellite

    Directory of Open Access Journals (Sweden)

    Hyeon Cheol Gong

    1998-06-01

    Full Text Available We consider the motion of the subsystems as separate bodies as well as the entire satellite for the attitude and orbit control of a communication satellite by multi-body modeling technique. Thus, the system can be applied to a general communication satellite as well as a specific communication satellite, i.e. Koreasat I, II. The simulation results can be viewed by two-dimensional graphics and three-dimensional animation. The graphical user interface (GUI makes its usage much simpler. We have simulated a couple of scenarios for Koreasat I, II which are being operated as geostationary communication satellites to verify the system performance.

  4. A case study in nonlinear dynamics and control of articulated spacecraft: The Space Station Freedom with a mobile remote manipulator system

    Science.gov (United States)

    Bennett, William H.; Kwatny, Harry G.; Lavigna, Chris; Blankenship, Gilmer

    1994-01-01

    The following topics are discussed: (1) modeling of articulated spacecraft as multi-flex-body systems; (2) nonlinear attitude control by adaptive partial feedback linearizing (PFL) control; (3) attitude dynamics and control for SSF/MRMS; and (4) performance analysis results for attitude control of SSF/MRMS.

  5. Shaded Spacecraft Radiators to Be Used on the Daytime Surface of the Mercury Planet, the Moon, and Asteroids of the Solar System Inner Part

    Directory of Open Access Journals (Sweden)

    V. A. Igrickii

    2016-01-01

    Full Text Available During the daytime a surface of the Moon, Mercury planet, and asteroids of the Solar system inner part, significantly heats up, and infrared radiation of the local soil becomes essential. At the same time direct solar radiation and reflected from the surface solar radiation reach the maximum too. These radiation fluxes can significantly decrease the efficiency of spacecraft radiators in the daytime. This effect is especially strong on the Mercury surface where direct solar radiation is 10 times stronger than solar radiation near the Earth. As a result, on the daytime surface of the Mercury the conventional low-temperature radiators become completely disabled.The article describes the development of the special shaded spacecraft radiators to be used in daytime on the Mercury and other atmosphereless bodies of the Solar system inner part. To solve this task are used mirror shades. The shape of these shades is developed to improve operation conditions of the spacecraft radiator through the appropriate scheme of radiation reflection. The task is discussed in 2D and 3D cases. A new design of shaded spacecraft radiators is proposed, and reasonable proportions of radiators are determined. The performance capability of proposed radiators for environments of the Mercury and the Moon is estimated using the zonal method in view of partial mirror reflection. The calculations showed that the developed shaded spacecraft radiators are capable to work on the Mercury surface as the low-temperature radiators even during the daytime. New radiators provide minimum accepted operating temperature of 241К (-32°С, meanwhile radiators of common design have minimum operating temperature of 479К (206°С. Using such radiators on the Moon enables us to increase effectiveness of spacecraft radiators and to decrease their minimum operating temperature from 270К (-3°С to 137К (-136°С.

  6. The Global Precipitation Measurement (GPM Spacecraft Power System Design and Orbital Performance

    Directory of Open Access Journals (Sweden)

    Dakermanji George

    2017-01-01

    The paper describes the power system design details, its performance to date and the lithium ion battery model that was developed for use in the energy balance analysis and is being used to predict the on-orbit health of the battery.

  7. Development of Educational Management System in Small Primary School

    Science.gov (United States)

    Alsammarry, Yupayao; Sirisuthi, Chaiyuth; Duangcharthom, Surat

    2016-01-01

    The purposes of the research were: (1) to study the factors of Educational Management System in Small Primary School; (2) to investigate current situations problems and guidelines of developing educational management in small primary school; (3) to develop Educational Management System in Small Primary School; and (4) to examine the results of…

  8. Modular Software for Spacecraft Navigation Using the Global Positioning System (GPS)

    Science.gov (United States)

    Truong, S. H.; Hartman, K. R.; Weidow, D. A.; Berry, D. L.; Oza, D. H.; Long, A. C.; Joyce, E.; Steger, W. L.

    1996-01-01

    The Goddard Space Flight Center Flight Dynamics and Mission Operations Divisions have jointly investigated the feasibility of engineering modular Global Positioning SYSTEM (GPS) navigation software to support both real time flight and ground postprocessing configurations. The goals of this effort are to define standard GPS data interfaces and to engineer standard, reusable navigation software components that can be used to build a broad range of GPS navigation support applications. The paper discusses the GPS modular software (GMOD) system and operations concepts, major requirements, candidate software architecture, feasibility assessment and recommended software interface standards. In additon, ongoing efforts to broaden the scope of the initial study and to develop modular software to support autonomous navigation using GPS are addressed,

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

    Science.gov (United States)

    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.

  10. Efficacy of Various Chemical Disinfectants on Biofilms Formed in Spacecraft Potable Water System Component

    Science.gov (United States)

    Wong, Willy; Garcia, Veronica; Castro, Victoria; Ott, Mark; Duane

    2009-01-01

    As the provision of potable water is critical for successful habitation of the International Space Station (ISS), life support systems were installed in December 2008 to recycle both humidity from the atmosphere and urine to conserve available water in the vehicle. Pre-consumption testing from the dispensing needle at the Potable Water Dispenser (PWD) indicated that bacterial concentrations exceeded the current ISS specifications of 50 colony forming units (CFU) per ml. Subsequent investigations revealed that a corrugated stainless steel flex hose upstream of the dispensing needle in the PWD was filled with non-sterile water and left at room temperature for over one month before launch. To simulate biofilm formation that was suspected in the flight system, sterile flex hoses were seeded with a consortium of bacterial isolates previously recovered from other ISS water systems, which included Ralstonia pickettii, Burkholderia multivorans, Caulobacter vibrioides., and Cupriavidus pauculus. After 5 days of incubation, these hoses were challenged with various chemical disinfectants including hydrogen peroxide, colloidal silver, and buffered pH solutions to determine the ability of the disinfectants to decrease and maintain bacterial concentrations below ISS specifications. Disinfection efficacy over time was measured by collecting daily heterotrophic plate counts following exposure to the disinfectants. A single flush with either 6% hydrogen peroxide solution or a mixture of 3% hydrogen peroxide and 400 ppb colloidal silver effectively reduced the bacterial concentrations to less than 1 CFU/ml for a period of up to 2 months. Testing results indicated that hydrogen peroxide and mixtures of hydrogen peroxide and colloidal silver have tremendous potential as alternative disinfectants for ISS water systems.

  11. Efficacy of various chemical disinfectants on biofilms formed in spacecraft potable water system components.

    Science.gov (United States)

    Wong, Wing C; Dudinsky, Lynn A; Garcia, Veronica M; Ott, Charlie M; Castro, Victoria A

    2010-07-01

    As the provision of potable water is critical for successful habitation of the International Space Station (ISS), life support systems were installed in December 2008 to recycle both humidity from the atmosphere and urine to conserve available water in the Station. In-flight pre-consumption testing from the dispensing needle at the Potable Water Dispenser (PWD) indicated that bacterial concentrations exceeded the current ISS specifications of 50 colony-forming units (CFU) ml(-1). Subsequent investigations revealed that a corrugated stainless steel flex hose upstream of the dispensing needle in the PWD was filled with nonsterile water and left at room temperature for more than 1 month before launch. To simulate biofilm formation that was suspected in the flight system, sterile flex hoses were seeded with a consortium of bacterial isolates previously recovered from other ISS water systems, including Ralstonia pickettii, Burkholderia multivorans, Caulobacter vibrioides, and Cupriavidus pauculus. After incubation for 5 days, the hoses were challenged with various chemical disinfectants including hydrogen peroxide (H2O2), colloidal silver, and buffered pH solutions to determine the ability of the disinfectants to decrease and maintain bacterial concentrations below ISS specifications. The disinfection efficacy over time was measured by collecting daily heterotrophic plate counts after exposure to the disinfectants. A single flush with either 6% H2O2 solution or a mixture of 3% H2O2 and 400 ppb colloidal silver effectively reduced the bacterial concentrations to <1 CFU ml(-1) for a period of up to 3 months.

  12. Exploration Mission Particulate Matter Filtration Technology Performance Testing in a Simulated Spacecraft Cabin Ventilation System

    Science.gov (United States)

    Agui, Juan H.; Vijayakumar, R.; Perry, Jay L.; Frederick, Kenneth R.; Mccormick, Robert M.

    2017-01-01

    Human deep space exploration missions will require advances in long-life, low maintenance airborne particulate matter filtration technology. As one of the National Aeronautics and Space Administrations (NASA) developments in this area, a prototype of a new regenerable, multi-stage particulate matter filtration technology was tested in an International Space Station (ISS) module simulation facility. As previously reported, the key features of the filter system include inertial and media filtration with regeneration and in-place media replacement techniques. The testing facility can simulate aspects of the cabin environment aboard the ISS and contains flight-like cabin ventilation system components. The filtration technology test article was installed at the inlet of the central ventilation system duct and instrumented to provide performance data under nominal flow conditions. In-place regeneration operations were also evaluated. The real-time data included pressure drop across the filter stages, process air flow rate, ambient pressure, humidity and temperature. In addition, two video cameras positioned at the filtration technology test articles inlet and outlet were used to capture the mechanical performance of the filter media indexing operation under varying air flow rates. Recent test results are presented and future design recommendations are discussed.

  13. Robust, Radiation Tolerant Command and Data Handling and Power System Electronics for SmallSats

    Science.gov (United States)

    Nguyen, Hanson Cao; Fraction, James

    2018-01-01

    In today's budgetary environment, there is significant interest within the National Aeronautics and Space Administration (NASA) to enable small robotic science missions that can be executed faster and cheaper than previous larger missions. To help achieve this, focus has shifted from using exclusively radiation-tolerant or radiation-hardened parts to using more commercial-off-the-shelf (COTS) components for NASA small satellite missions that can last at least one year in orbit. However, there are some portions of a spacecraft's avionics, such as the Command and Data Handling (C&DH) subsystem and the Power System Electronics (PSE) that need to have a higher level of reliability that goes beyond what is attainable with currently available COTS parts. While there are a number of COTS components that can withstand a total ionizing dose (TID) of tens or hundreds of kilorads, there is still a great deal of concern about tolerance to and mitigation of single-event effects (SEE).

  14. Development of a non-cryogenic nitrogen/oxygen supply system. [for spacecraft environments

    Science.gov (United States)

    1977-01-01

    Modular components were refined or replaced to improve the performance of the electrolysis module in a system which generates both oxygen and hydrogen from hydrazine hydrate. Significant mechanical and electrical performance improvements were achieved in the cathode. Improvements were also made in the phase separation area but at considerable cost in time and money and to the detriment of other investigative areas. Only the pump/bubble separator failed in a manner necessitating redesign. Its failure was, however, due to its being operated above the temperature range for which it was designed. The basic electrolysis cell design was not changed.

  15. Emergency strategy optimization for the environmental control system in manned spacecraft

    Science.gov (United States)

    Li, Guoxiang; Pang, Liping; Liu, Meng; Fang, Yufeng; Zhang, Helin

    2018-02-01

    It is very important for a manned environmental control system (ECS) to be able to reconfigure its operation strategy in emergency conditions. In this article, a multi-objective optimization is established to design the optimal emergency strategy for an ECS in an insufficient power supply condition. The maximum ECS lifetime and the minimum power consumption are chosen as the optimization objectives. Some adjustable key variables are chosen as the optimization variables, which finally represent the reconfigured emergency strategy. The non-dominated sorting genetic algorithm-II is adopted to solve this multi-objective optimization problem. Optimization processes are conducted at four different carbon dioxide partial pressure control levels. The study results show that the Pareto-optimal frontiers obtained from this multi-objective optimization can represent the relationship between the lifetime and the power consumption of the ECS. Hence, the preferred emergency operation strategy can be recommended for situations when there is suddenly insufficient power.

  16. Magnesium fluoride as energy storage medium for spacecraft solar thermal power systems

    Science.gov (United States)

    Lurio, Charles A.

    1992-01-01

    MgF2 was investigated as a phase-change energy-storage material for LEO power systems using solar heat to run thermal cycles. It provides a high heat of fusion per unit mass at a high melting point (1536 K). Theoretical evaluation showed the basic chemical compatibility of liquid MgF2 with refractory metals at 1600 K, though transient high pressures of H2 can occur in a closed container due to reaction with residual moisture. The compatibility was tested in two refractory metal containers for over 2000 h. Some showed no deterioration, while there was evidence that the fluoride reacted with hafnium in others. Corollary tests showed that the MgF2 supercooled by 10-30 K and 50-90 K.

  17. Spacecraft exploration of asteroids

    International Nuclear Information System (INIS)

    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

  18. Gravity Probe B spacecraft description

    International Nuclear Information System (INIS)

    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)

  19. Putting Integrated Systems Health Management Capabilities to Work: Development of an Advanced Caution and Warning System for Next-Generation Crewed Spacecraft Missions

    Science.gov (United States)

    Mccann, Robert S.; Spirkovska, Lilly; Smith, Irene

    2013-01-01

    Integrated System Health Management (ISHM) technologies have advanced to the point where they can provide significant automated assistance with real-time fault detection, diagnosis, guided troubleshooting, and failure consequence assessment. To exploit these capabilities in actual operational environments, however, ISHM information must be integrated into operational concepts and associated information displays in ways that enable human operators to process and understand the ISHM system information rapidly and effectively. In this paper, we explore these design issues in the context of an advanced caution and warning system (ACAWS) for next-generation crewed spacecraft missions. User interface concepts for depicting failure diagnoses, failure effects, redundancy loss, "what-if" failure analysis scenarios, and resolution of ambiguity groups are discussed and illustrated.

  20. State-of-the-Art for Small Satellite Propulsion Systems

    Science.gov (United States)

    Parker, Khary I.

    2016-01-01

    SmallSats are a low cost access to space with an increasing need for propulsion systems. NASA, and other organizations, will be using SmallSats that require propulsion systems to: a) Conduct high quality near and far reaching on-orbit research and b) Perform technology demonstrations. Increasing call for high reliability and high performing for SmallSat components. Many SmallSat propulsion technologies are currently under development: a) Systems at various levels of maturity and b) Wide variety of systems for many mission applications.

  1. Estimating Torque Imparted on Spacecraft Using Telemetry

    Science.gov (United States)

    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.

  2. SMALL HYDRO PLANTS IN LAND USE SYSTEM PLANNING IN POLAND

    Directory of Open Access Journals (Sweden)

    Anita Bernatek

    2014-10-01

    Full Text Available Small hydropower plants are present in the land use system planning in Poland. At the national level the important role of spatial planning in the development of renewable energy was highlighted, included small hydroplants. However, it seems that at the regional level this demand has not been realized. The necessity of developing small hydroplants as a renewable energy was highlighted, but negative environmental impact was not indicated. At local level legal instrument of small hydropower plants is specified.

  3. Spacecraft rendezvous and docking

    DEFF Research Database (Denmark)

    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...

  4. Toward autonomous spacecraft

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  6. Attitude coordination for spacecraft formation with multiple communication delays

    Directory of Open Access Journals (Sweden)

    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.

  7. Thermodynamics of small systems two volumes bound as one

    CERN Document Server

    Hill, Terrel L

    1994-01-01

    This authoritative summary of the basics of small system, or nonmacroscopic, thermodynamics was written by the field's founder. Originally published in two volumes, the text remains essential reading in an area in which the practical aim is to derive equations that provide interconnections among various thermodynamic functions. Part I introduces the basics of small system thermodynamics, exploring environmental variables, noting throughout the ways in which small thermodynamic systems differ operationally from macroscopic systems. Part II explores binding on macromolecules and aggregation, completes the discussion of environmental variables, and includes brief summaries of certain special topics, including electric and magnetic fields, spherical drops and bubbles, and polydisperse systems.

  8. SSTI- Lewis Spacecraft Nickel-Hydrogen Battery

    Science.gov (United States)

    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.

  9. A Geology Sampling System for Small Bodies

    Science.gov (United States)

    Naids, Adam J.; Hood, Anthony D.; Abell, Paul; Graff, Trevor; Buffington, Jesse

    2016-01-01

    Human exploration of microgravity bodies is being investigated as a precursor to a Mars surface mission. Asteroids, comets, dwarf planets, and the moons of Mars all fall into this microgravity category and some are being discussed as potential mission targets. Obtaining geological samples for return to Earth will be a major objective for any mission to a small body. Currently, the knowledge base for geology sampling in microgravity is in its infancy. Humans interacting with non-engineered surfaces in microgravity environment pose unique challenges. In preparation for such missions a team at the NASA Johnson Space Center has been working to gain experience on how to safely obtain numerous sample types in such an environment. This paper describes the type of samples the science community is interested in, highlights notable prototype work, and discusses an integrated geology sampling solution.

  10. Theoretical Studies of Small-System Thermodynamics in Energetic Materials

    Science.gov (United States)

    2016-01-06

    SECURITY CLASSIFICATION OF: This is a comprehensive theoretical research program to investigate the fundamental principles of small-system thermodynamics ...a.k.a. nanothermodynamics). The proposed work is motivated by our desire to better understand the fundamental dynamics and thermodynamics of...for Public Release; Distribution Unlimited Final Report: Theoretical Studies of Small-System Thermodynamics in Energetic Materials The views, opinions

  11. Small pipe characterization system (SPCS) conceptual design

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, M.O.; Ferrante, T.A.; McKay, M.D.

    1995-01-01

    Throughout the Department of Energy (DOE) complex there are many facilities that have been identified for Decontamination and Decommissioning (D&D). As processes are terminated or brought off-line, facilities are placed on the inactive list, and facility managers and site contractors are required to assure a safe and reliable decommissioning and transition of these facilities to a clean final state. Decommissioning of facilities requires extensive reliable characterization, decontamination and in some cases dismantlement. Characterization of piping systems throughout the DOE complex is becoming more and more necessary. In addition to decommissioning activities, characterization activities are performed as part of surveillance and maintenance (S&M). Because of the extent of contamination, all inactive facilities require some type of S&M. These S&M activities include visual assessment, equipment and material accounting, and maintenance. The majority of the inactive facilities have piping systems 3 inches or smaller that are inaccessible because they are contaminated, imbedded in concrete, or run through hot cells. Many of these piping systems have been inactive for a number of years and there exists no current system condition information or the historical records are poor and/or missing altogether. Many of these piping systems are placed on the contaminated list, not because of known contamination, but because of the risk of internal contamination. Many of the piping systems placed on the contamination list may not have internal contamination. Because there is a potential however, they are treated as such. The cost of D&D can be greatly reduced by identifying and removing hot spot contamination, leaving clean piping to be removed using conventional methods. Accurate characterization of these piping systems is essential before, during and after all D&D activities.

  12. Small pipe characterization system (SPCS) conceptual design

    International Nuclear Information System (INIS)

    Anderson, M.O.; Ferrante, T.A.; McKay, M.D.

    1995-01-01

    Throughout the Department of Energy (DOE) complex there are many facilities that have been identified for Decontamination and Decommissioning (D ampersand D). As processes are terminated or brought off-line, facilities are placed on the inactive list, and facility managers and site contractors are required to assure a safe and reliable decommissioning and transition of these facilities to a clean final state. Decommissioning of facilities requires extensive reliable characterization, decontamination and in some cases dismantlement. Characterization of piping systems throughout the DOE complex is becoming more and more necessary. In addition to decommissioning activities, characterization activities are performed as part of surveillance and maintenance (S ampersand M). Because of the extent of contamination, all inactive facilities require some type of S ampersand M. These S ampersand M activities include visual assessment, equipment and material accounting, and maintenance. The majority of the inactive facilities have piping systems 3 inches or smaller that are inaccessible because they are contaminated, imbedded in concrete, or run through hot cells. Many of these piping systems have been inactive for a number of years and there exists no current system condition information or the historical records are poor and/or missing altogether. Many of these piping systems are placed on the contaminated list, not because of known contamination, but because of the risk of internal contamination. Many of the piping systems placed on the contamination list may not have internal contamination. Because there is a potential however, they are treated as such. The cost of D ampersand D can be greatly reduced by identifying and removing hot spot contamination, leaving clean piping to be removed using conventional methods. Accurate characterization of these piping systems is essential before, during and after all D ampersand D activities

  13. 47 CFR 76.934 - Small systems and small cable companies.

    Science.gov (United States)

    2010-10-01

    ... files with its franchising authority or the Commission the documentation necessary to qualify for the... equity interest in the system or exercises de jure control over the system. (b) A franchising authority... regulations. (c) Initial regulation of small systems: (1) If certified by the Commission, a local franchising...

  14. Manually operated small envelope scanner system

    Energy Technology Data Exchange (ETDEWEB)

    Sword, Charles Keith

    2017-04-18

    A scanner system and method for acquisition of position-based ultrasonic inspection data are described. The scanner system includes an inspection probe and a first non-contact linear encoder having a first sensor and a first scale to track inspection probe position. The first sensor is positioned to maintain a continuous non-contact interface between the first sensor and the first scale and to maintain a continuous alignment of the first sensor with the inspection probe. The scanner system may be used to acquire two-dimensional inspection probe position data by including a second non-contact linear encoder having a second sensor and a second scale, the second sensor positioned to maintain a continuous non-contact interface between the second sensor and the second scale and to maintain a continuous alignment of the second sensor with the first sensor.

  15. Assessing the sustainability of small wastewater systems

    DEFF Research Database (Denmark)

    Hoffmann, Birgitte; Nielsen, Susanne Balslev; Elle, Morten

    1999-01-01

    The authors present a planning tool for comparing and assessing the sustainability of different wastewater systems. The core of the planning tool is an assessment method based on both technical and social elements. The point of departure is that no technique is inherently sustainable or ecological...... in itself, but that the sustainability of the total system of technologies for a particular settlement in a given location must be assessed in a holistic and transparent manner. A pilot case is used to demonstrate the structure and the results of the assessment method. The assessment method is still under...

  16. Vortex system studies on small wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Montgomerie, Bjoern; Dahlberg, Jan-Aake [Swedish Defence Research Agency, Stockholm (Sweden). Div. of Aeronautics, FFA

    2003-10-01

    The wind tunnel experiment reported included a small wind turbine setup and smoke to visualize the trailing tip vortices for different wind turbine configurations. Several combinations of tunnel wind speeds and tip speed ratios generated a database where the end result functions were radius and pitch, of the tip vortex spirals, versus the downstream coordinate. The Reynolds number in the experiment was very low compared to that of full size turbines. The results should therefore be seen as valid only for low Reynolds numbers. The models were 18 and 25 cm diameter turbines. This is thought to be complementary to the information obtained in similar wind tunnel investigations for much larger models. The database is meant to be a fundamental tool for the construction of practical aerodynamic induction methods. Such methods typically employ the Biot-Savart law has been shown to lead to a flow field, which deviates considerably from that of reality. E.g. concentration into tip vortices does not happen when the flow is simulated with Biot-Savart law only. Thus, a combination of the induction method and its modification, based on investigations such as the one reported, is foreseen to replace the widely used Blade Element Momentum method for wind turbine loads and performance prediction.

  17. Space micropropulsion systems for Cubesats and small satellites: From proximate targets to furthermost frontiers

    Science.gov (United States)

    Levchenko, Igor; Bazaka, Kateryna; Ding, Yongjie; Raitses, Yevgeny; Mazouffre, Stéphane; Henning, Torsten; Klar, Peter J.; Shinohara, Shunjiro; Schein, Jochen; Garrigues, Laurent; Kim, Minkwan; Lev, Dan; Taccogna, Francesco; Boswell, Rod W.; Charles, Christine; Koizumi, Hiroyuki; Shen, Yan; Scharlemann, Carsten; Keidar, Michael; Xu, Shuyan

    2018-03-01

    Rapid evolution of miniaturized, automatic, robotized, function-centered devices has redefined space technology, bringing closer the realization of most ambitious interplanetary missions and intense near-Earth space exploration. Small unmanned satellites and probes are now being launched in hundreds at a time, resurrecting a dream of satellite constellations, i.e., wide, all-covering networks of small satellites capable of forming universal multifunctional, intelligent platforms for global communication, navigation, ubiquitous data mining, Earth observation, and many other functions, which was once doomed by the extraordinary cost of such systems. The ingression of novel nanostructured materials provided a solid base that enabled the advancement of these affordable systems in aspects of power, instrumentation, and communication. However, absence of efficient and reliable thrust systems with the capacity to support precise maneuvering of small satellites and CubeSats over long periods of deployment remains a real stumbling block both for the deployment of large satellite systems and for further exploration of deep space using a new generation of spacecraft. The last few years have seen tremendous global efforts to develop various miniaturized space thrusters, with great success stories. Yet, there are critical challenges that still face the space technology. These have been outlined at an inaugural International Workshop on Micropropulsion and Cubesats, MPCS-2017, a joint effort between Plasma Sources and Application Centre/Space Propulsion Centre (Singapore) and the Micropropulsion and Nanotechnology Lab, the G. Washington University (USA) devoted to miniaturized space propulsion systems, and hosted by CNR-Nanotec—P.Las.M.I. lab in Bari, Italy. This focused review aims to highlight the most promising developments reported at MPCS-2017 by leading world-reputed experts in miniaturized space propulsion systems. Recent advances in several major types of small

  18. Minimization of small bowel volume within treatment fields using customized small bowel displacement system (SBDS)

    International Nuclear Information System (INIS)

    Lim, D. H.; Huh, S. J.; Ahn, Y. C.; Kim, D. Y.; Wu, H. G.; Kim, M. K.; Choi, D. R.; Shin, K. H.

    1997-01-01

    Authors designed a customized Small Bowel Displacement System(SBDS) to displace the small bowel from the pelvic radiation fields and minimize treatment-related bowel morbidities. From August 1995 to May 1996, 55 consecutive patients who received pelvic radiation therapy with the SBDS were included in this study. The SBDS consists of a customized styrofoam compression device which can displace the small bowel from the radiation fields and an individualized immobilization abdominal board for easy daily setup in prone position. After opacifying the small bowel with Barium, the patients were laid prone and posterior-anterior (PA) and lateral (LAT) simulation films were taken with and without the SBDS. The areas of the small bowel included in the radiation fields with and without the SBDS were compared. Using the SBDS, the mean small bowel area was reduced by 59% on PA and 51% on LAT films (P=0.0001). In six patients (6/55, 11%), it was possible that no small bowel was included within the treatment fields. The mean upward displacement of the most caudal small bowel was 4.8 cm using the SBDS. Only 15% (8/55) of patients treated with the SBDS manifested diarrhea requiring medication. The SBDS is a novel method that can be used to displace the small bowel away from the treatment portal effectively and reduce the radiation therapy morbidities. Compliance with setup is excellent when the SBDS is used. (author)

  19. Small and medium business in the contractual relationship system

    Directory of Open Access Journals (Sweden)

    Obalyaeva Julia, I.

    2015-01-01

    Full Text Available The paper reveals the role of small and medium business in the national economy. The comparative analysis of the indicators characterizing the development of small business in Russia, South Korea and France is given are compared. Two laws that support small and medium businesses in public purchasing. The author’s vision of the problems of development of small and medium-sized businesses in the Russian Federation and specification of the path of the national economy development is presented. Two schemes, revealing the organization of interaction of large corporate sector and the sector of small and medium-sized enterprises in the system of contractual relations and analysis of internal and external factors in the development of small and medium-sized enterprises are presented. The experience of conducting digital auctions with participation of small businesses on an digital platform CJSC "Sberbank AST" is considered.

  20. Power system small signal stability analysis and control

    CERN Document Server

    Mondal, Debasish; Sengupta, Aparajita

    2014-01-01

    Power System Small Signal Stability Analysis and Control presents a detailed analysis of the problem of severe outages due to the sustained growth of small signal oscillations in modern interconnected power systems. The ever-expanding nature of power systems and the rapid upgrade to smart grid technologies call for the implementation of robust and optimal controls. Power systems that are forced to operate close to their stability limit have resulted in the use of control devices by utility companies to improve the performance of the transmission system against commonly occurring power system

  1. Environmental charging of spacecraft-tests of thermal control materials for use on the global positioning system flight space vehicle. Part 2: Specimen 6 to 9

    Science.gov (United States)

    Stevens, N. J.; Berkopec, F. D.; Blech, R. A.

    1976-01-01

    The NASA/USAF program on the Environmental Charging of Spacecraft Surfaces consists, in part, of experimental efforts directed toward evaluating the response of materials to the environmental charged particle flux. Samples of thermal blankets of the type to be used on the Global Positioning System Flight Space Vehicles were tested to determine their response to electron flux. The primary result observed was that no discharges were obtained with the quartz-fiber-fabric-covered multilayer insulation specimen. The taped aluminized polyester grounding system used on all specimens did not appear to grossly deteriorate with time; however, the specimens require specific external pressure to maintain constant grounding system resistance.

  2. Small Bore Piping Socket Weld Evaluation System

    International Nuclear Information System (INIS)

    Lee, Dong Min; Cho, Hong Seok; Choi, Sang Hoon; Cho, Ki Hyun; Lee, Jang Wook

    2009-01-01

    Kori unit 3 had stopped operation due to leakage at Steam Generator drain line socket weld on June 6, 2008. The Cause of socket weld damage was known as a fatigue crack. According to this case, all socket welds located in RCS pressure boundary are carrying out Radiographic Testing. But to inspect socket welds by RT has some problems. The result of EPRI study showed that RT has limitation to find flaws at socket welds.The orientation of flaws has big influence on RT inspection capability and there is not enough space at socket welds for RT, dose problems as well. Although the gap between coupling and pipe at socket welds must follow up code, surface inspection can't inspect the gap. If there is absence of the gap, socket welds are damaged during operation. The gap should be identified by RT but the distance of gap can't be measured. As this paper, the ultrasonic inspection system was introduced to figure out indication and gap in the socket welds

  3. FINANCING ASSISTANCE AVAILABLE FOR SMALL PUBLIC WATER SYSTEMS

    Science.gov (United States)

    Many small and very small drinking water systems require repair and upgrading if they are to comply with the Safe Drinking Water Act of 1974 and its amendments. Often, dispersed population makes infracstructure expensive on a per-capita basis. Funding shortages at the federal, ...

  4. Industry consultation on grid connection of small PV systems

    Energy Technology Data Exchange (ETDEWEB)

    Knight, J.; Thorneycroft, J.; Cotterell, M.; Gambro, S.

    2000-07-01

    This report presents the results of consultation within the PV industry and the electricity supply industry concerning guidelines for the connection of small PV systems to the electricity network. (author)

  5. Artist concept of Galileo spacecraft

    Science.gov (United States)

    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.

  6. Financing and disseminating small energy systems in rural areas

    International Nuclear Information System (INIS)

    Waddle, D.B.; Perlack, R.D.

    1992-01-01

    The viability of small energy systems, primarily photovoltaic systems, is discussed as an alternative for rural electrification via traditional grid extension. A dissemination model that incorporates financing to allow access to a much larger population of users and technology support (e.g. training for sales and service and small business development) is described. The experience of two successful programs is presented to illustrate the keys to effective program development and implementation. (author)

  7. Spacecraft Spin Test Facility

    Data.gov (United States)

    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...

  8. Small SWAP 3D imaging flash ladar for small tactical unmanned air systems

    Science.gov (United States)

    Bird, Alan; Anderson, Scott A.; Wojcik, Michael; Budge, Scott E.

    2015-05-01

    The Space Dynamics Laboratory (SDL), working with Naval Research Laboratory (NRL) and industry leaders Advanced Scientific Concepts (ASC) and Hood Technology Corporation, has developed a small SWAP (size, weight, and power) 3D imaging flash ladar (LAser Detection And Ranging) sensor system concept design for small tactical unmanned air systems (STUAS). The design utilizes an ASC 3D flash ladar camera and laser in a Hood Technology gyro-stabilized gimbal system. The design is an autonomous, intelligent, geo-aware sensor system that supplies real-time 3D terrain and target images. Flash ladar and visible camera data are processed at the sensor using a custom digitizer/frame grabber with compression. Mounted in the aft housing are power, controls, processing computers, and GPS/INS. The onboard processor controls pointing and handles image data, detection algorithms and queuing. The small SWAP 3D imaging flash ladar sensor system generates georeferenced terrain and target images with a low probability of false return and system SWAP estimate of system is modeled using LadarSIM, a MATLAB® and Simulink®- based ladar system simulator designed and developed by the Center for Advanced Imaging Ladar (CAIL) at Utah State University. We will present the concept design and modeled performance predictions.

  9. High energy density propulsion systems and small engine dynamometer

    Science.gov (United States)

    Hays, Thomas

    2009-07-01

    Scope and Method of Study. This study investigates all possible methods of powering small unmanned vehicles, provides reasoning for the propulsion system down select, and covers in detail the design and production of a dynamometer to confirm theoretical energy density calculations for small engines. Initial energy density calculations are based upon manufacturer data, pressure vessel theory, and ideal thermodynamic cycle efficiencies. Engine tests are conducted with a braking type dynamometer for constant load energy density tests, and show true energy densities in excess of 1400 WH/lb of fuel. Findings and Conclusions. Theory predicts lithium polymer, the present unmanned system energy storage device of choice, to have much lower energy densities than other conversion energy sources. Small engines designed for efficiency, instead of maximum power, would provide the most advantageous method for powering small unmanned vehicles because these engines have widely variable power output, loss of mass during flight, and generate rotational power directly. Theoretical predictions for the energy density of small engines has been verified through testing. Tested values up to 1400 WH/lb can be seen under proper operating conditions. The implementation of such a high energy density system will require a significant amount of follow-on design work to enable the engines to tolerate the higher temperatures of lean operation. Suggestions are proposed to enable a reliable, small-engine propulsion system in future work. Performance calculations show that a mature system is capable of month long flight times, and unrefueled circumnavigation of the globe.

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

    Science.gov (United States)

    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.

  11. Mars, the Moon, and the Ends of the Earth: Autonomy for Small Reactor Power Systems

    International Nuclear Information System (INIS)

    Wood, Richard Thomas

    2008-01-01

    In recent years, the National Aeronautics and Space Administration (NASA) has been considering deep space missions that utilize a small-reactor power system (SRPS) to provide energy for propulsion and spacecraft power. Additionally, application of SRPS modules as a planetary power source is being investigated to enable a continuous human presence for nonpolar lunar sites and on Mars. A SRPS can supply high-sustained power for space and surface applications that is both reliable and mass efficient. The use of small nuclear reactors for deep space or planetary missions presents some unique challenges regarding the operations and control of the power system. Current-generation terrestrial nuclear reactors employ varying degrees of human control and decision-making for operations and benefit from periodic human interaction for maintenance. In contrast, the control system of a SRPS employed for deep space missions must be able to accommodate unattended operations due to communications delays and periods of planetary occlusion while adapting to evolving or degraded conditions with no opportunity for repair or refurbishment. While surface power systems for planetary outposts face less extreme delays and periods of isolation and may benefit from limited maintenance capabilities, considerations such as human safety, resource limitations and usage priorities, and economics favor minimizing direct, continuous human interaction with the SRPS for online, dedicated power system management. Thus, a SRPS control system for space or planetary missions must provide capabilities for operational autonomy. For terrestrial reactors, large-scale power plants remain the preferred near-term option for nuclear power generation. However, the desire to reduce reliance on carbon-emitting power sources in developing countries may lead to increased consideration of SRPS modules for local power generation in remote regions that are characterized by emerging, less established infrastructures

  12. Investigation of longitudinal control system for a small hydrofoil boat

    Science.gov (United States)

    Phillips, W. H.; Shaughnessy, J. D.

    1976-01-01

    An analysis of a hydromechanical system for longitudinal control of a small hydrofoil boat is presented. The system incorporates height and acceleration sensors operating flaps on the foils through a mechanical linkage. Effects of some of the system parameters on the stability and response to waves are shown. The results indicate that the system is capable of providing adequate stability, but the response to stern waves at low frequencies is larger than desired.

  13. Large Scale Experiments on Spacecraft Fire Safety

    Science.gov (United States)

    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

  14. Small Water System Alternatives: Media and Membrane Filtration Alternatives for Small Communities and Households

    Science.gov (United States)

    This webinar presentation will highlight research case studies on innovative drinking water treatment alternatives for small community water systems. Emphasis will be placed on media and membrane filtration technologies capable of meeting the requirements of the Long-Term 2 Enha...

  15. Practical Applications of Cosmic Ray Science: Spacecraft, Aircraft, Ground-Based Computation and Control Systems, Exploration, and Human Health and Safety

    Science.gov (United States)

    Koontz, Steve

    2015-01-01

    In this presentation a review of galactic cosmic ray (GCR) effects on microelectronic systems and human health and safety is given. The methods used to evaluate and mitigate unwanted cosmic ray effects in ground-based, atmospheric flight, and space flight environments are also reviewed. However not all GCR effects are undesirable. We will also briefly review how observation and analysis of GCR interactions with planetary atmospheres and surfaces and reveal important compositional and geophysical data on earth and elsewhere. About 1000 GCR particles enter every square meter of Earth’s upper atmosphere every second, roughly the same number striking every square meter of the International Space Station (ISS) and every other low- Earth orbit spacecraft. GCR particles are high energy ionized atomic nuclei (90% protons, 9% alpha particles, 1% heavier nuclei) traveling very close to the speed of light. The GCR particle flux is even higher in interplanetary space because the geomagnetic field provides some limited magnetic shielding. Collisions of GCR particles with atomic nuclei in planetary atmospheres and/or regolith as well as spacecraft materials produce nuclear reactions and energetic/highly penetrating secondary particle showers. Three twentieth century technology developments have driven an ongoing evolution of basic cosmic ray science into a set of practical engineering tools needed to design, test, and verify the safety and reliability of modern complex technological systems and assess effects on human health and safety effects. The key technology developments are: 1) high altitude commercial and military aircraft; 2) manned and unmanned spacecraft; and 3) increasingly complex and sensitive solid state micro-electronics systems. Space and geophysical exploration needs drove the development of the instruments and analytical tools needed to recover compositional and structural data from GCR induced nuclear reactions and secondary particle showers. Finally, the

  16. Small magnetic energy storage systems using high temperature superconductors

    International Nuclear Information System (INIS)

    Kumar, B.

    1991-01-01

    This paper reports on magnetic energy storage for power systems that has been considered for commercial utility power, air and ground mobile power sources, and spacecraft applications. Even at the current technology limits of energy storage (100 KJ/Kg*), superconducting magnetic energy storage inductors do not offer a strong advantage over state-of-the-art batteries. The commercial utility application does not have a weight and volume limitation, and is under intense study in several countries for diurnal cycle energy storage and high power delivery. The advent of high temperature superconductors has reduced one of the penalties of superconducting magnetic energy storage in that refrigeration and cryocontainers become greatly simplified. Still, structural and current density issues that limit the energy density and size of superconducting inductors do not change. Cold weather starting of aircraft engines is an application where these limitations are not as significant, and where current systems lack performance. The very cold environments make it difficult to achieve high power densities in state-of-the-art batteries and hydraulically activated starters. The same cold environments make it possible to cool superconducting systems for weeks using a single charge of liquid nitrogen. At the same, the ground carts can handle the size and weight of superconducting magnetic storage (SMES) devices

  17. Nonequilibrium statistical mechanics and stochastic thermodynamics of small systems

    International Nuclear Information System (INIS)

    Tu Zhanchun

    2014-01-01

    Thermodynamics is an old subject. The research objects in conventional thermodynamics are macroscopic systems with huge number of particles. In recent 30 years, thermodynamics of small systems is a frontier topic in physics. Here we introduce nonequilibrium statistical mechanics and stochastic thermodynamics of small systems. As a case study, we construct a Canot-like cycle of a stochastic heat engine with a single particle controlled by a time-dependent harmonic potential. We find that the efficiency at maximum power is 1 - √T c /T h , where Tc and Th are the temperatures of cold bath and hot bath, respectively. (author)

  18. Designing of network planning system for small-scale manufacturing

    Science.gov (United States)

    Kapulin, D. V.; Russkikh, P. A.; Vinnichenko, M. V.

    2018-05-01

    The paper presents features of network planning in small-scale discrete production. The procedure of explosion of the production order, considering multilevel representation, is developed. The software architecture is offered. Approbation of the network planning system is carried out. This system allows carrying out dynamic updating of the production plan.

  19. Small wind power systems: market, applications, architectures and energy management

    International Nuclear Information System (INIS)

    Roboam, X.

    2005-01-01

    Context and stakes of small wind power systems are described in this paper by situating both supply and demand as well as the main application fields. Technical issues are then concerned in terms of system structure, energy management and network connection. (author)

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

    Data.gov (United States)

    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...

  1. Improved Traceability of a Small Satellite Mission Concept to Requirements Using Model Based System Engineering

    Science.gov (United States)

    Reil, Robin L.

    2014-01-01

    Model Based Systems Engineering (MBSE) has recently been gaining significant support as a means to improve the "traditional" document-based systems engineering (DBSE) approach to engineering complex systems. In the spacecraft design domain, there are many perceived and propose benefits of an MBSE approach, but little analysis has been presented to determine the tangible benefits of such an approach (e.g. time and cost saved, increased product quality). This paper presents direct examples of how developing a small satellite system model can improve traceability of the mission concept to its requirements. A comparison of the processes and approaches for MBSE and DBSE is made using the NASA Ames Research Center SporeSat CubeSat mission as a case study. A model of the SporeSat mission is built using the Systems Modeling Language standard and No Magic's MagicDraw modeling tool. The model incorporates mission concept and requirement information from the mission's original DBSE design efforts. Active dependency relationships are modeled to demonstrate the completeness and consistency of the requirements to the mission concept. Anecdotal information and process-duration metrics are presented for both the MBSE and original DBSE design efforts of SporeSat.

  2. Airborne particulate matter in spacecraft

    Science.gov (United States)

    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.

  3. Spacecraft Health Automated Reasoning Prototype (SHARP): The fiscal year 1989 SHARP portability evaluations task for NASA Solar System Exploration Division's Voyager project

    Science.gov (United States)

    Atkinson, David J.; Doyle, Richard J.; James, Mark L.; Kaufman, Tim; Martin, R. Gaius

    1990-01-01

    A Spacecraft Health Automated Reasoning Prototype (SHARP) portability study is presented. Some specific progress is described on the portability studies, plans for technology transfer, and potential applications of SHARP and related artificial intelligence technology to telescience operations. The application of SHARP to Voyager telecommunications was a proof-of-capability demonstration of artificial intelligence as applied to the problem of real time monitoring functions in planetary mission operations. An overview of the design and functional description of the SHARP system is also presented as it was applied to Voyager.

  4. Chaos as the hub of systems dynamics. The part I-The attitude control of spacecraft by involving in the heteroclinic chaos

    Science.gov (United States)

    Doroshin, Anton V.

    2018-06-01

    In this work the chaos in dynamical systems is considered as a positive aspect of dynamical behavior which can be applied to change systems dynamical parameters and, moreover, to change systems qualitative properties. From this point of view, the chaos can be characterized as a hub for the system dynamical regimes, because it allows to interconnect separated zones of the phase space of the system, and to fulfill the jump into the desirable phase space zone. The concretized aim of this part of the research is to focus on developing the attitude control method for magnetized gyrostat-satellites, which uses the passage through the intentionally generated heteroclinic chaos. The attitude dynamics of the satellite/spacecraft in this case represents the series of transitions from the initial dynamical regime into the chaotic heteroclinic regime with the subsequent exit to the final target dynamical regime with desirable parameters of the attitude dynamics.

  5. Spectra and spacecraft

    Science.gov (United States)

    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.

  6. Security for small computer systems a practical guide for users

    CERN Document Server

    Saddington, Tricia

    1988-01-01

    Security for Small Computer Systems: A Practical Guide for Users is a guidebook for security concerns for small computers. The book provides security advice for the end-users of small computers in different aspects of computing security. Chapter 1 discusses the security and threats, and Chapter 2 covers the physical aspect of computer security. The text also talks about the protection of data, and then deals with the defenses against fraud. Survival planning and risk assessment are also encompassed. The last chapter tackles security management from an organizational perspective. The bo

  7. Propulsion Trade Studies for Spacecraft Swarm Mission Design

    Science.gov (United States)

    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.

  8. SHARP - Automated monitoring of spacecraft health and status

    Science.gov (United States)

    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.

  9. SHARP: Automated monitoring of spacecraft health and status

    Science.gov (United States)

    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.

  10. Anchoring Technology for In Situ Exploration of Small Bodie

    Science.gov (United States)

    Steltzner, A.; Nasif, A.

    2000-01-01

    Comets, asteroids and other small bodies found in the solar system do not possess enough gravity to ensure spacecraft contact forces sufficient to allow many types of in situ science, such as core or surface sampling.

  11. Small and Shaping the Future Energy Eco-house System

    Science.gov (United States)

    Furukawa, Ryuzo; Takahashi, Hideyuki; Sato, Yoshinori; Sasaki, Hiroshi; Isu, Norifumi; Ohtsuka, Masuo; Tohji, Kazuyuki

    2010-11-01

    The objective of this research is to develop the elemental technology of the small and thin energy collection system from water, wind, and others in the house, and examine them at the eco-house which will be built at Tohoku University on March 2010. This small energy storage system will contribute to reduce 10% of greenhouse gas emission from household electricity. This project is done by three following groups. 1st group (NEC-Tokin Co. Ltd.) will develop the technologies on the accumulation of electric power pressured from low electric power in which electricity is generated and on the cooperation with AC power supply used for domestic use for this eco-house system. 2nd group (INAX Co. Ltd.) will develop the elemental technology of the slight energy collection system from tap water in the home using a small hydroelectric generator for this eco-house system. 3rd group (Shoei Co. Ltd.) will develop the technologies on existent magnetic gear device, health appliances (Exercise bike), wind power generator, for this eco-house system. Tokoku University compiles these groups. Furthermore, I develop a search of unused small energy and the use technology, and propose a new energy supply system using solar cell and Li ion secondary battery.

  12. Autonomous spacecraft rendezvous and docking

    Science.gov (United States)

    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.

  13. FEM Simulation of Small Wind Power Generating System Using PMSG

    Science.gov (United States)

    Kesamaru, Katsumi; Ohno, Yoshihiro; Sonoda, Daisuke

    The paper describes a new approach to simulate the small wind power generating systems using PMSG, in which the output is connected to constant resistive load, such as heaters, through the rectifier and the dc chopper. The dynamics of the wind power generating system is presented, and it is shown by simulation results that this approach is useful for system dynamics, such as starting phenomena.

  14. Electromagnetic fields in small systems from a multiphase transport model

    Science.gov (United States)

    Zhao, Xin-Li; Ma, Yu-Gang; Ma, Guo-Liang

    2018-02-01

    We calculate the electromagnetic fields generated in small systems by using a multiphase transport (AMPT) model. Compared to A +A collisions, we find that the absolute electric and magnetic fields are not small in p +Au and d +Au collisions at energies available at the BNL Relativistic Heavy Ion Collider and in p +Pb collisions at energies available at the CERN Large Hadron Collider. We study the centrality dependencies and the spatial distributions of electromagnetic fields. We further investigate the azimuthal fluctuations of the magnetic field and its correlation with the fluctuating geometry using event-by-event simulations. We find that the azimuthal correlation 〈" close="〉cos(ϕα+ϕβ-2 ΨRP)〉">cos2 (ΨB-Ψ2) between the magnetic field direction and the second-harmonic participant plane is almost zero in small systems with high multiplicities, but not in those with low multiplicities. This indicates that the charge azimuthal correlation is not a valid probe to study the chiral magnetic effect (CME) in small systems with high multiplicities. However, we suggest searching for possible CME effects in small systems with low multiplicities.

  15. Experimental overview on small colliding systems at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Stankus, Paul

    2016-12-15

    Beginning with the observation of ridge/flow-like features in pair correlations measurements in p+Pb, d+Au and high-density p+p events at RHIC and LHC, the last few years have seen a great surge of interest in the question of whether anything like a hot, locally-equilibrated QCD medium is formed in the small systems at collider energies. Many intriguing and suggestive results have been presented, but conclusions about medium formation must be approached with care. This presentation will attempt to summarize the experimental results from small colliding systems measured at RHIC, as part of a careful and objective evaluation of this question.

  16. ANL small-sample calorimeter system design and operation

    International Nuclear Information System (INIS)

    Roche, C.T.; Perry, R.B.; Lewis, R.N.; Jung, E.A.; Haumann, J.R.

    1978-07-01

    The Small-Sample Calorimetric System is a portable instrument designed to measure the thermal power produced by radioactive decay of plutonium-containing fuels. The small-sample calorimeter is capable of measuring samples producing power up to 32 milliwatts at a rate of one sample every 20 min. The instrument is contained in two packages: a data-acquisition module consisting of a microprocessor with an 8K-byte nonvolatile memory, and a measurement module consisting of the calorimeter and a sample preheater. The total weight of the system is 18 kg

  17. Power requirements for commercial communications spacecraft

    Science.gov (United States)

    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.

  18. A bio-inspired electrocommunication system for small underwater robots.

    Science.gov (United States)

    Wang, Wei; Liu, Jindong; Xie, Guangming; Wen, Li; Zhang, Jianwei

    2017-03-29

    Weakly electric fishes (Gymnotid and Mormyrid) use an electric field to communicate efficiently (termed electrocommunication) in the turbid waters of confined spaces where other communication modalities fail. Inspired by this biological phenomenon, we design an artificial electrocommunication system for small underwater robots and explore the capabilities of such an underwater robotic communication system. An analytical model for electrocommunication is derived to predict the effect of the key parameters such as electrode distance and emitter current of the system on the communication performance. According to this model, a low-dissipation, and small-sized electrocommunication system is proposed and integrated into a small robotic fish. We characterize the communication performance of the robot in still water, flowing water, water with obstacles and natural water conditions. The results show that underwater robots are able to communicate electrically at a speed of around 1 k baud within about 3 m with a low power consumption (less than 1 W). In addition, we demonstrate that two leader-follower robots successfully achieve motion synchronization through electrocommunication in the three-dimensional underwater space, indicating that this bio-inspired electrocommunication system is a promising setup for the interaction of small underwater robots.

  19. Multiplicity fluctuations and collective flow in small colliding systems

    Science.gov (United States)

    Kawaguchi, Koji; Murase, Koichi; Hirano, Tetsufumi

    2017-11-01

    Recent observation of collective-flow-like behaviours in small colliding systems attracts significant theoretical and experimental interests. In large colliding systems, large collective flow has been interpreted as manifestation of almost-perfect fluidity of the quark gluon plasma (QGP). So it is quite intriguing to explore how small the QGP can be as a fluid. Multiplicity fluctuations play a crucial role in centrality definition of the events in small colliding systems since the fluctuations are, in general, more important as the system size is getting smaller. To consider the correct multiplicity fluctuations, we employ PYTHIA which naturally describes multiplicity distribution in p+p collisions. We superpose p+p collisions by taking into account the number of participants and that of binary collisions from Monte-Carlo version of Glauber model and evaluate initial entropy density distributions which contain not only multiplicity fluctuations but also fluctuations of longitudinal profiles. Solving hydrodynamic equations followed by the hadronic afterburner, we calculate transverse momentum spectra, elliptic and triangular flow parameters in p+Au, d+Au and 3He+Au collisions at the RHIC energy and p+Pb collisions at the LHC energy. Although a large fraction of final anisotropic flow parameters comes from the fluid-dynamical stage, the effects of hadronic rescatterings turn out to be also important as well in understanding of the flow data in small colliding systems.

  20. Spacecraft Design Thermal Control Subsystem

    Science.gov (United States)

    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.

  1. Status of integration of small computers into NDE systems

    International Nuclear Information System (INIS)

    Dau, G.J.; Behravesh, M.M.

    1988-01-01

    Introduction of computers in nondestructive evaluations (NDE) has enabled data acquisition devices to provide a more thorough and complete coverage in the scanning process, and has aided human inspectors in their data analysis and decision making efforts. The price and size/weight of small computers, coupled with recent increases in processing and storage capacity, have made small personal computers (PC's) the most viable platform for NDE equipment. Several NDE systems using minicomputers and newer PC-based systems, capable of automatic data acquisition, and knowledge-based analysis of the test data, have been field tested in the nuclear power plant environment and are currently available through commercial sources. While computers have been in common use for several NDE methods during the last few years, their greatest impact, however, has been on ultrasonic testing. This paper discusses the evolution of small computers and their integration into the ultrasonic testing process

  2. Kyiv Small Rivers in Metropolis Water Objects System

    Science.gov (United States)

    Krelshteyn, P.; Dubnytska, M.

    2017-12-01

    The article answers the question, what really are the small underground rivers with artificial watercourses: water bodies or city engineering infrastructure objects? The place of such rivers in metropolis water objects system is identified. The ecological state and the degree of urbanization of small rivers, as well as the dynamics of change in these indicators are analysed on the Kiev city example with the help of water objects cadastre. It was found that the registration of small rivers in Kyiv city is not conducted, and the summary information on such water objects is absent and is not taken into account when making managerial decisions at the urban level. To solve this problem, we propose to create some water bodies accounting system (water cadastre).

  3. Small Wind Electric Systems: A U.S. Consumer's Guide

    International Nuclear Information System (INIS)

    O'Dell, K.

    2001-01-01

    The U.S. Consumer's Guide for Small Wind Electric systems provides consumers with enough information to help them determine if a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include: how to make your home more energy efficient, how to choose the right size turbine, the parts of a wind electric system, determining if there is enough wind resource on your site, choosing the best site for your turbine, connecting your system to the utility grid, and if it's possible to become independent of the utility grid using wind energy

  4. Small Wind Electric Systems An Alaska Consumer's Guide

    International Nuclear Information System (INIS)

    O'Dell, K.

    2001-01-01

    The Alaska Consumer's Guide for Small Wind Electric Systems provides consumers with enough information to help them determine if a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include: how to make your home more energy efficient, how to choose the right size turbine, the parts of a wind electric system, determining if there is enough wind resource on your site, choosing the best site for your turbine, connecting your system to the utility grid, and if it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a state wind resource map and a list of state incentives and state contacts for more information

  5. Small Wind Electric Systems: A Kansas Consumer's Guide

    International Nuclear Information System (INIS)

    O'Dell, K.

    2001-01-01

    The Kansas Consumer's Guide for Small Wind Electric Systems provides consumers with enough information to help them determine if a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include: how to make your home more energy efficient, how to choose the right size turbine, the parts of a wind electric system, determining if there is enough wind resource on your site, choosing the best site for your turbine, connecting your system to the utility grid, and if it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of state incentives and state contacts for more information

  6. Small Wind Electric Systems: A New Mexico Consumer's Guide

    International Nuclear Information System (INIS)

    O'Dell, K.

    2001-01-01

    The New Mexico Consumer's Guide for Small Wind Electric Systems provides consumers with enough information to help them determine if a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include: how to make your home more energy efficient, how to choose the right size turbine, the parts of a wind electric system, determining if there is enough wind resource on your site, choosing the best site for your turbine, connecting your system to the utility grid, and if it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a state wind resource map and a list of state incentives and state contacts for more information

  7. Small Wind Electric Systems: A Vermont Consumer's Guide

    International Nuclear Information System (INIS)

    O'Dell, K.

    2001-01-01

    The Vermont Consumer's Guide for Small Wind Electric Systems provides consumers with enough information to help them determine if a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include: how to make your home more energy efficient, how to choose the right size turbine, the parts of a wind electric system, determining if there is enough wind resource on your site, choosing the best site for your turbine, connecting your system to the utility grid, and if it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a state wind resource map and a list of state incentives and state contacts for more information

  8. Small Wind Electric Systems: A South Dakota Consumer's Guide

    International Nuclear Information System (INIS)

    O'Dell, K.

    2001-01-01

    The South Dakota Consumer's Guide for Small Wind Electric Systems provides consumers with enough information to help them determine if a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include: how to make your home more energy efficient, how to choose the right size turbine, the parts of a wind electric system, determining if there is enough wind resource on your site, choosing the best site for your turbine, connecting your system to the utility grid, and if it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a state wind resource map and a list of state incentives and state contacts for more information

  9. Fractionated Spacecraft Architectures Seeding Study

    National Research Council Canada - National Science Library

    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...

  10. Spacecraft Material Outgassing Data

    Data.gov (United States)

    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...

  11. Spacecraft Fire Safety Demonstration

    Data.gov (United States)

    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...

  12. Quick spacecraft charging primer

    International Nuclear Information System (INIS)

    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.

  13. Redesigning a collection system for "small" consumer electronics

    NARCIS (Netherlands)

    Melissen, Franciscus

    2006-01-01

    This paper establishes that the collection system within the recycling scheme for consumer electronics in the Netherlands has not been entirely successful in convincing consumers to hand in their used appliances by means of dedicated collection routes. Particularly regarding small appliances,

  14. Small Drinking Water Systems Communication and Outreach Highlights

    Science.gov (United States)

    As part of our small drinking water systems efforts, this poster highlights several communications and outreach highlights that EPA's Office of Research and Development and Office of Water have been undertaking in collaboration with states and the Association of State Drinking Wa...

  15. Computed tomography of the central nervous system in small animals

    International Nuclear Information System (INIS)

    Tipold, A.; Tipold, E.

    1991-01-01

    With computed tomography in 44 small animals some well defined anatomical structures and pathological processes of the central nervous system are described. Computed tomography is not only necessary for the diagnosis of tumors; malformations, inflammatory, degenerative and vascular diseases and traumas are also visible

  16. Smart solar tanks for small solar domestic hot water systems

    DEFF Research Database (Denmark)

    Furbo, Simon; Andersen, Elsa; Knudsen, Søren

    2005-01-01

    Investigation of small SDHW systems based on smart solar tanks are presented. The domestic water in a smart solar tank can be heated both by solar collectors and by means of an auxiliary energy supply system. The auxiliary energy supply system – in this study electric heating elements – heats up...... systems, based on differently designed smart solar tanks and a traditional SDHW system were investigated by means of laboratory experiments and theoretical calculations. The investigations showed that the yearly thermal performance of SDHW systems with smart solar tanks is 5-35% higher than the thermal...... performance of traditional SDHW systems. Estimates indicate that the performance/cost ratio can be improved by up to 25% by using a smart solar tank instead of a traditional tank when the backup energy system is electric heating elements. Further, smart solar tanks are suitable for unknown, variable, large...

  17. Chinese very small aperture terminal system for ministries

    Science.gov (United States)

    Dan, Sen

    The objective and technologic approach of the Chinese very small aperture terminal (VSAT) system of data communications is described in this paper. The system is primarily designed for the management business of many governmental ministries and administrations. It consists of a centralized processing and switching facility and a number of groups of remote terminals. The network is constructed in a star configuration because of simplicity and the inherent nature of the management business. Either Intelsat of Chinese domestic communications satellite can be used for the space segment. The system performance has been verified by field trials. Some results of system analysis can be used for traffic design.

  18. Small Water System Management Program: 100 K Area

    International Nuclear Information System (INIS)

    Hunacek, G.S. Jr.

    1995-01-01

    Purposes of this document are: to provide an overview of the service and potable water system presently in service at the Hanford Site's 100 K Area; to provide future system forecasts based on anticipated DOE activities and programs; to delineate performance, design, and operations criteria; and to describe planned improvements. The objective of the small water system management program is to assure the water system is properly and reliably managed and operated, and continues to exist as a functional and viable entity in accordance with WAC 246-290-410

  19. Deployable Brake for Spacecraft

    Science.gov (United States)

    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.

  20. Development of a Magnetoencephalograph System for Small Animals

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. E.; Kim, I. S.; Kang, C. S.; Kwon, H.; Kim, J. M.; Lee, Y. H.; Kim, K. [Brain and Cognition Measurement Laboratory, Korea Research Institute of Standards and Science(KRISS), Daejeon (Korea, Republic of)

    2011-08-15

    We developed a four-channel first order gradiometer system to measure magnetoencephalogram for mice. We used double relaxation oscillation SQUID (DROS). The diameter of the pickup coil is 4 mm and the distance between the coils is 5 mm. Coil distance was designed to have good spatial resolution for a small mouse brain. We evaluated the current dipole localization confidence region for a mouse brain, using the spherical conductor model. The white noise of the measurement system was about 30 fT/Hz{sup 1/2}/cm when measured in a magnetically shielded room. We measured magnetic signal from a phantom having the same size of a mouse brain, which was filled with 0.9% saline solution. The results suggest that the developed system has a feasibility to study the functions of brain of small animals.

  1. Development of a Magnetoencephalograph System for Small Animals

    International Nuclear Information System (INIS)

    Kim, J. E.; Kim, I. S.; Kang, C. S.; Kwon, H.; Kim, J. M.; Lee, Y. H.; Kim, K.

    2011-01-01

    We developed a four-channel first order gradiometer system to measure magnetoencephalogram for mice. We used double relaxation oscillation SQUID (DROS). The diameter of the pickup coil is 4 mm and the distance between the coils is 5 mm. Coil distance was designed to have good spatial resolution for a small mouse brain. We evaluated the current dipole localization confidence region for a mouse brain, using the spherical conductor model. The white noise of the measurement system was about 30 fT/Hz 1/2 /cm when measured in a magnetically shielded room. We measured magnetic signal from a phantom having the same size of a mouse brain, which was filled with 0.9% saline solution. The results suggest that the developed system has a feasibility to study the functions of brain of small animals.

  2. Integral design method for simple and small Mars lander system using membrane aeroshell

    Science.gov (United States)

    Sakagami, Ryo; Takahashi, Ryohei; Wachi, Akifumi; Koshiro, Yuki; Maezawa, Hiroyuki; Kasai, Yasko; Nakasuka, Shinichi

    2018-03-01

    To execute Mars surface exploration missions, spacecraft need to overcome the difficulties of the Mars entry, descent, and landing (EDL) sequences. Previous landing missions overcame these challenges with complicated systems that could only be executed by organizations with mature technology and abundant financial resources. In this paper, we propose a novel integral design methodology for a small, simple Mars lander that is achievable even by organizations with limited technology and resources such as universities or emerging countries. We aim to design a lander (including its interplanetary cruise stage) whose size and mass are under 1 m3 and 150 kg, respectively. We adopted only two components for Mars EDL process: a "membrane aeroshell" for the Mars atmospheric entry and descent sequence and one additional mechanism for the landing sequence. The landing mechanism was selected from the following three candidates: (1) solid thrusters, (2) aluminum foam, and (3) a vented airbag. We present a reasonable design process, visualize dependencies among parameters, summarize sizing methods for each component, and propose the way to integrate these components into one system. To demonstrate the effectiveness, we applied this methodology to the actual Mars EDL mission led by the National Institute of Information and Communications Technology (NICT) and the University of Tokyo. As a result, an 80 kg class Mars lander with a 1.75 m radius membrane aeroshell and a vented airbag was designed, and the maximum landing shock that the lander will receive was 115 G.

  3. Changes in shifting cultivation systems on small Pacific islands

    DEFF Research Database (Denmark)

    Mertz, Ole; Birch-Thomsen, Torben; Elberling, Bo

    2012-01-01

    The limited information on change in shifting cultivation systems of small islands of the Pacific stands in contrast to increasing evidence of this farming system's demise in other parts of the tropics. Here, we assess changes in agricultural activities during the past 40 years of Bellona Island......, Solomon Islands, where shifting cultivation is still maintained in the traditional way. Fallow length has increased despite population growth due to redistribution of the cultivated area, migration-induced extensification and changes in crops. Productivity of the farming system remains high although...

  4. DET/MPS - THE GSFC ENERGY BALANCE PROGRAM, DIRECT ENERGY TRANSFER/MULTIMISSION SPACECRAFT MODULAR POWER SYSTEM (MACINTOSH A/UX VERSION)

    Science.gov (United States)

    Jagielski, J. M.

    1994-01-01

    The DET/MPS programs model and simulate the Direct Energy Transfer and Multimission Spacecraft Modular Power System in order to aid both in design and in analysis of orbital energy balance. Typically, the DET power system has the solar array directly to the spacecraft bus, and the central building block of MPS is the Standard Power Regulator Unit. DET/MPS allows a minute-by-minute simulation of the power system's performance as it responds to various orbital parameters, focusing its output on solar array output and battery characteristics. While this package is limited in terms of orbital mechanics, it is sufficient to calculate eclipse and solar array data for circular or non-circular orbits. DET/MPS can be adjusted to run one or sequential orbits up to about one week, simulated time. These programs have been used on a variety of Goddard Space Flight Center spacecraft projects. DET/MPS is written in FORTRAN 77 with some VAX-type extensions. Any FORTRAN 77 compiler that includes VAX extensions should be able to compile and run the program with little or no modifications. The compiler must at least support free-form (or tab-delineated) source format and 'do do-while end-do' control structures. DET/MPS is available for three platforms: GSC-13374, for DEC VAX series computers running VMS, is available in DEC VAX Backup format on a 9-track 1600 BPI tape (standard distribution) or TK50 tape cartridge; GSC-13443, for UNIX-based computers, is available on a .25 inch streaming magnetic tape cartridge in UNIX tar format; and GSC-13444, for Macintosh computers running AU/X with either the NKR FORTRAN or AbSoft MacFORTRAN II compilers, is available on a 3.5 inch 800K Macintosh format diskette. Source code and test data are supplied. The UNIX version of DET requires 90K of main memory for execution. DET/MPS was developed in 1990. A/UX and Macintosh are registered trademarks of Apple Computer, Inc. VMS, DEC VAX and TK50 are trademarks of Digital Equipment Corporation. UNIX is a

  5. DET/MPS - THE GSFC ENERGY BALANCE PROGRAM, DIRECT ENERGY TRANSFER/MULTIMISSION SPACECRAFT MODULAR POWER SYSTEM (DEC VAX VMS VERSION)

    Science.gov (United States)

    Jagielski, J. M.

    1994-01-01

    The DET/MPS programs model and simulate the Direct Energy Transfer and Multimission Spacecraft Modular Power System in order to aid both in design and in analysis of orbital energy balance. Typically, the DET power system has the solar array directly to the spacecraft bus, and the central building block of MPS is the Standard Power Regulator Unit. DET/MPS allows a minute-by-minute simulation of the power system's performance as it responds to various orbital parameters, focusing its output on solar array output and battery characteristics. While this package is limited in terms of orbital mechanics, it is sufficient to calculate eclipse and solar array data for circular or non-circular orbits. DET/MPS can be adjusted to run one or sequential orbits up to about one week, simulated time. These programs have been used on a variety of Goddard Space Flight Center spacecraft projects. DET/MPS is written in FORTRAN 77 with some VAX-type extensions. Any FORTRAN 77 compiler that includes VAX extensions should be able to compile and run the program with little or no modifications. The compiler must at least support free-form (or tab-delineated) source format and 'do do-while end-do' control structures. DET/MPS is available for three platforms: GSC-13374, for DEC VAX series computers running VMS, is available in DEC VAX Backup format on a 9-track 1600 BPI tape (standard distribution) or TK50 tape cartridge; GSC-13443, for UNIX-based computers, is available on a .25 inch streaming magnetic tape cartridge in UNIX tar format; and GSC-13444, for Macintosh computers running AU/X with either the NKR FORTRAN or AbSoft MacFORTRAN II compilers, is available on a 3.5 inch 800K Macintosh format diskette. Source code and test data are supplied. The UNIX version of DET requires 90K of main memory for execution. DET/MPS was developed in 1990. A/UX and Macintosh are registered trademarks of Apple Computer, Inc. VMS, DEC VAX and TK50 are trademarks of Digital Equipment Corporation. UNIX is a

  6. Describing phase coexistence in systems with small phases

    International Nuclear Information System (INIS)

    Lovett, R

    2007-01-01

    Clusters of atoms can be studied in molecular beams and by computer simulation; 'liquid drops' provide elementary models for atomic nuclei and for the critical nuclei of nucleation theory. These clusters are often described in thermodynamic terms, but the behaviour of small clusters near a phase boundary is qualitatively different from the behaviour at a first order phase transition in idealized thermodynamics. In the idealized case the density and entropy show mathematically sharp discontinuities when the phase boundary is crossed. In large, but finite, systems, the phase boundaries become regions of state space wherein these properties vary rapidly but continuously. In small clusters with a large surface/volume ratio, however, the positive interfacial free energy makes it unlikely, even in states on phase boundaries, that a cluster will have a heterogeneous structure. What is actually seen in these states is a structure that fluctuates in time between homogeneous structures characteristic of the two sides of the phase boundary. That is, structural fluctuations are observed. Thermodynamics only predicts average properties; statistical mechanics is required to understand these fluctuations. Failure to distinguish thermodynamic properties and characterizations of fluctuations, particularly in the context of first order phase transitions, has led to suggestions that the classical rules for thermodynamic stability are violated in small systems and that classical thermodynamics provides an inconsistent description of these systems. Much of the confusion stems from taking statistical mechanical identifications of thermodynamic properties, explicitly developed for large systems, and applying them uncritically to small systems. There are no inconsistencies if thermodynamic properties are correctly identified and the distinction between thermodynamic properties and fluctuations is made clear

  7. Spacecraft Tests of General Relativity

    Science.gov (United States)

    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.

  8. DESIGN OF SMALL AUTOMATION WORK CELL SYSTEM DEMONSTRATIONS

    International Nuclear Information System (INIS)

    TURNER, C.; PEHL, J.

    2000-01-01

    The introduction of automation systems into many of the facilities dealing with the production, use and disposition of nuclear materials has been an ongoing objective. Many previous attempts have been made, using a variety of monolithic and, in some cases, modular technologies. Many of these attempts were less than successful, owing to the difficulty of the problem, the lack of maturity of the technology, and over optimism about the capabilities of a particular system. Consequently, it is not surprising that suggestions that automation can reduce worker Occupational Radiation Exposure (ORE) levels are often met with skepticism and caution. The development of effective demonstrations of these technologies is of vital importance if automation is to become an acceptable option for nuclear material processing environments. The University of Texas Robotics Research Group (UTRRG) has been pursuing the development of technologies to support modular small automation systems (each of less than 5 degrees-of-freedom) and the design of those systems for more than two decades. Properly designed and implemented, these technologies have a potential to reduce the worker ORE associated with work in nuclear materials processing facilities. Successful development of systems for these applications requires the development of technologies that meet the requirements of the applications. These application requirements form a general set of rules that applicable technologies and approaches need to adhere to, but in and of themselves are generally insufficient for the design of a specific automation system. For the design of an appropriate system, the associated task specifications and relationships need to be defined. These task specifications also provide a means by which appropriate technology demonstrations can be defined. Based on the requirements and specifications of the operations of the Advanced Recovery and Integrated Extraction System (ARIES) pilot line at Los Alamos National

  9. Mechanical Design of Spacecraft

    Science.gov (United States)

    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.

  10. Small Systems and Limitations on the Use of Chemical Thermodynamics

    Science.gov (United States)

    Tovbin, Yu. K.

    2018-01-01

    Limitations on using chemical thermodynamics to describe small systems are formulated. These limitations follow from statistical mechanics for equilibrium and nonequilibrium processes and reflect (1) differences between characteristic relaxation times in momentum, energy, and mass transfer in different aggregate states of investigated systems; (2) achievements of statistical mechanics that allow us to determine criteria for the size of smallest region in which thermodynamics can be applied and the scale of the emergence of a new phase, along with criteria for the conditions of violating a local equilibrium. Based on this analysis, the main thermodynamic results are clarified: the phase rule for distorted interfaces, the sense and area of applicability of Gibbs's concept of passive forces, and the artificiality of Kelvin's equation as a result of limitations on the thermodynamic approach to considering small bodies. The wrongness of introducing molecular parameters into thermodynamic derivations, and the activity coefficient for an activated complex into the expression for a reaction rate constant, is demonstrated.

  11. The PSI/ETH small radiocarbon dating system

    International Nuclear Information System (INIS)

    Synal, H.-A.; Jacob, S.; Suter, M.

    2000-01-01

    A small and compact radiocarbon dating system has been built at PSI/ETH. The system is based on a National Electrostatics Corporation (NEC) pelletron accelerator with a maximum terminal voltage of 550 kV. It is the first accelerator mass spectrometry (AMS) system that uses 1 + ions at the high-energy end of the accelerator. Interfering isobaric molecules are destroyed by collisions in the gas stripper inside the accelerator. The system has been designed to fulfill two primary goals. First, it can be used as an experimental platform to study the relevant charge exchange and molecular break up processes at low energies. Second, it is able to perform high quality radiocarbon dating measurements. A detailed system description is given and results of performance tests are discussed

  12. Hydropower harvesting from a small scale reciprocating system

    Energy Technology Data Exchange (ETDEWEB)

    Malla, Ramesh B.; Shrestha, Binu; Bagtzoglou, Amvrossios; Drasdis, Jonathon [Department of Civil and Environmental Engineering, University of Connecticut, 261 Glenbrook Road, Storrs, CT 06269-2037 (United States); Johnson, Paul [eGen LLC, 1084 Shennecossett Road, Groton, CT 06340 (United States)

    2011-05-15

    Conventional hydropower systems that can take advantage of low head movement of water require substantial flow rates. However, these systems cannot harvest hydro energy from small sources of water with low head and low discharge, such as streams and creeks. The reciprocating hydropower system discussed in this paper can harvest power from such low flow discharge and low head sources. This paper presents a detailed proof-of-concept study of the hydropower model, including the underlining theoretical principles. Laboratory test results demonstrating the dependence of the lift force in the reciprocating small scale hydropower model as a function of flow velocity, size and rotational speed of the cylinder and comparison of the results with a previous study are also included. Two methods of power harvesting from the output displacement obtained from the hydropower system are discussed. The first employs electromagnetic induction principles and the other is based on a linear inertial generator using a conventional second order spring mass damper system. Finally, results from a finite element analysis of the hydropower system are presented and facilitate future design of the structural aspects of the housing for the reciprocating cylinder. (author)

  13. Heavy-flavour transport: from large to small systems

    Energy Technology Data Exchange (ETDEWEB)

    Beraudo, A.; De Pace, A.; Monteno, M.; Nardi, M.; Prino, F.

    2016-12-15

    Predictions for heavy-flavour production in relativistic heavy-ion experiments provided by the POWLANG transport setup, including now also an in-medium hadronization model, are displayed, After showing some representative findings for the Au-Au and Pb-Pb cases, a special focus will be devoted to the results obtained in the small systems formed in proton(deuteron)-nucleus collisions, where recent experimental data suggest the possible formation of a medium featuring a collective behaviour.

  14. Small intestinal bacterial overgrowth in patients with systemic sclerosis

    Directory of Open Access Journals (Sweden)

    Saara Rawn

    2017-01-01

    Full Text Available Small intestinal bacterial overgrowth (SIBO is common in patients with systemic sclerosis (SSc yet often goes underrecognized in clinical practice. In patients with SSc, untreated SIBO may result in marked morbidity and possible mortality. The pathogenesis of SIBO is multifactorial and relates to immune dysregulation, vasculopathy, and dysmotility. This article reviews various diagnostic approaches and therapeutic options for SIBO. Treatment modalities mainly include prokinetics, probiotics, and antibiotics.

  15. Aerial Remote Radio Frequency Identification System for Small Vessel Monitoring

    Science.gov (United States)

    2009-12-01

    technology as a tool that can benefit everyone (Warner 2008, p.144). Lippitt’s model , coupled with Vroom and Lawler’s Expectancy Theory (Miner 2005, p...Identification System for Small Vessel Monitoring 6. AUTHOR( S ) Jason Appler, Sean Finney, Michael McMellon 5. FUNDING NUMBERS 7. PERFORMING...ORGANIZATION NAME( S ) AND ADDRESS(ES) Naval Postgraduate School Monterey, CA 93943-5000 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING

  16. Systems analysis for the development of small resource recovery systems: system performance data. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Crnkovich, P G; Helmstetter, A J

    1980-10-01

    The technologies that should be developed to make small-scale solid waste processing facilities attractive and viable for small municipalities with solid waste between 50 and 250 tons per day are identified. The resource recovery systems investigated were divided into three categories: thermal processng, mechanical separation, and biological processing. Thermal processing systems investigated are: excess-air incineration; starved-air incineration/gasification; and pyrolysis (indirect heating). Mechanical processing systems investigated are: coarse refuse derived fuel; materials separation; dust refuse derived fuel; densified refuse derived fuel; and fine refuse derived fuel. Mechanical processing components investigated include: receiving module; primary size reduction module; combustible separation module; refuse derived fuel preparation module; fuel densification; fuel storage module; ferrous separation; and building and facilities. Pretreatment processes and principle methods of bioconversion of MSW dealing with biological processing are investigated. (MCW)

  17. Automated constraint checking of spacecraft command sequences

    Science.gov (United States)

    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.

  18. Abnormalities of small bowel and colon in systemic sclerosis

    International Nuclear Information System (INIS)

    Scutellari, P.N.; Cinotti, A.; Cavallari, L.; Orzincolo, C.; Dovigo, L.; Trotta, F.; Menegale, G.

    1990-01-01

    A series of 21 subjects (2 males and 19 females) affected with systemic sclerosis, was examined by small bowel (oral and intubation methods) and colon enema. The underlying process responsible for abnormalities in the small bowel and colon in systemic sclerosis is a variable and pacthy destruction of the muscularis propria, that produces the structural and functional changes detected on X-ray: Pathologic condition is the same affecting the esophagus. The scout film of the abdomen often reveals colonic distension and fecal impaction, so that it may be quite difficult to prepare adequately the patients for a barium enema. Peristalsis may be virtually absent in short segments, and transit time may be several time longer than that in normal patients. For these reasons, intestinal pseudo-obstruction may appear in systemic sclerosis. The observed radiographic changes are: 1) in the small bowel: a) dilatation of the gut, especially in its proximal portions (duodenum and jejunum), in which the valvulae conniventes are straightened, normal or thinned; b) presence of diverticula, 2-4 cm in diameter, with hemispherical shape without the neck-like opening into the bowel lumen; 2) in the colon, the characteristic finding is an increase in size of individual haustra, forming sacculations or pseudo-diverticula, usually on the antemesenteric border of the transverse colon, better demonstrated on post-evacuation film. Moreover, loss of colonic haustration is also observed associated to colonic elongation and dilatation

  19. Detection of gravitational radiation by the Doppler tracking of spacecraft

    International Nuclear Information System (INIS)

    Mashhoon, B.

    1979-01-01

    It has been suggested that the residual Doppler shift in the precision electromagnetic tracking of spacecraft be used to search for gravitational radiation that may be incident on the Earth-spacecraft system. The influence of a gravitational wave on the Doppler shift is calculated, and it is found that the residual shift is dominated by two terms: one is due to the passage of electromagnetic waves through the gravitational radiation field, and the other depends on the change in the relative velocity of the Earth and the spacecraft caused by the external wave. A detailed analysis is given of the influence of gravitational radiation on a binary system with an orbital size small compared to the wavelength of the incident radiation. It is shown that, as a consequence of the interaction with the external wave, the system makes a transition from one Keplerian orbit into another which, in general, has a different energy and angular momentum. It is therefore proposed to search for such effects in the solar system. Observations of the orbit of an artificial Earth satellite, the lunar orbit, and especially the planetary orbits offer exciting possibilities for the detection of gravitational waves of various wavelengths. From the results of the lunar laser ranging experiment and the range measurement to Mars, certain interesting limits may be established on the frequency of incidence of gravitational waves of a given flux on the Earth-Moon and the Earth-Mars systems. This is followed by a brief and preliminary analysis of the possibility of detecting gravitational radiation by measuring a residual secular Doppler shift in the satellite-to-satellite Doppler tracking of two counterorbiting drag-free spacecraft around the Earth as in the Van Patten-Everitt experiment

  20. Small file aggregation in a parallel computing system

    Science.gov (United States)

    Faibish, Sorin; Bent, John M.; Tzelnic, Percy; Grider, Gary; Zhang, Jingwang

    2014-09-02

    Techniques are provided for small file aggregation in a parallel computing system. An exemplary method for storing a plurality of files generated by a plurality of processes in a parallel computing system comprises aggregating the plurality of files into a single aggregated file; and generating metadata for the single aggregated file. The metadata comprises an offset and a length of each of the plurality of files in the single aggregated file. The metadata can be used to unpack one or more of the files from the single aggregated file.

  1. Small Aircraft Transportation System Higher Volume Operations Concept

    Science.gov (United States)

    Abbott, Terence S.; Consiglio, Maria C.; Baxley, Brian T.; Williams, Daniel M.; Jones, Kenneth M.; Adams, Catherine A.

    2006-01-01

    This document defines the Small Aircraft Transportation System (SATS) Higher Volume Operations concept. The general philosophy underlying this concept is the establishment of a newly defined area of flight operations called a Self-Controlled Area (SCA). Within the SCA, pilots would take responsibility for separation assurance between their aircraft and other similarly equipped aircraft. This document also provides details for a number of off-nominal and emergency procedures which address situations that could be expected to occur in a future SCA. The details for this operational concept along with a description of candidate aircraft systems to support this concept are provided.

  2. Intelligent spacecraft module

    Science.gov (United States)

    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

  3. The Small Explorer Data System - A data system based on standard interfaces

    Science.gov (United States)

    Smith, Brian S.; Hengemihle, Jerome

    1990-01-01

    The Small Explorer Data System was developed by NASA Goddard Space Flight Center using a 'standard interfaces' approach. Standard interfaces make it adaptable to a wide variety of missions. The paper describes the Small Explorer Data System with particular emphasis on the standard interfaces incorporated in both the hardware and software.

  4. Clinical diagnostic system using a small cyclotron for medical use

    International Nuclear Information System (INIS)

    Yonekura, Y.; Magata, Y.; Konishi, J.

    1990-01-01

    Since a small cyclotron and a positron emission tomography (PET) scanner have been installed at the Kyoto University Hospital in 1983, a great deal of effort has been directed to the clinical application of the PET-cyclotron system. This paper outlines the experience with PET in the clinical setting, including the facility, equipments and staff involved, weekly schedule, typical clinical protocols, and some results from the patients. The system consists of small cyclotron for production of the short-lived positron emitting radionuclides, fully automated synthesis system for labeling various compounds, scanning for measurement of radioactivities, and data analysis system for calculating physiological parameters. A resolving cylinder target system with eight smaller cylinders is equipped for production of C-11, N-13, O-15, and F-18. Labeled compounds are quickly delivered to the PET scanner room by two systems--the continuous delivery system for the labeled gas and the rapid delivery system for the liquid compounds by compressed air. A PET scanner devoted for clinical studies is a multislice whole-body PET scanner. Ten PET studies are performed weekly on the average for measuring blood flow and oxygen and glucose metabolism in the brain, blood flow and glucose and fatty acid metabolism in the heart, blood flow and amino acid uptake in the pancreas, lung ventilation, and tumor glucose metabolism. The availability of PET-cyclotron system is still limited in view of cost. The previous clinical studies suggest the contribution of PET to the the understanding of the mechanism of disease pathophysiology. (N.K.)

  5. Energy harvesting concepts for small electric unmanned systems

    Science.gov (United States)

    Qidwai, Muhammad A.; Thomas, James P.; Kellogg, James C.; Baucom, Jared N.

    2004-07-01

    In this study, we identify and survey energy harvesting technologies for small electrically powered unmanned systems designed for long-term (>1 day) time-on-station missions. An environmental energy harvesting scheme will provide long-term, energy additions to the on-board energy source. We have identified four technologies that cover a broad array of available energy sources: solar, kinetic (wind) flow, autophagous structure-power (both combustible and metal air-battery systems) and electromagnetic (EM) energy scavenging. We present existing conceptual designs, critical system components, performance, constraints and state-of-readiness for each technology. We have concluded that the solar and autophagous technologies are relatively matured for small-scale applications and are capable of moderate power output levels (>1 W). We have identified key components and possible multifunctionalities in each technology. The kinetic flow and EM energy scavenging technologies will require more in-depth study before they can be considered for implementation. We have also realized that all of the harvesting systems require design and integration of various electrical, mechanical and chemical components, which will require modeling and optimization using hybrid mechatronics-circuit simulation tools. This study provides a starting point for detailed investigation into the proposed technologies for unmanned system applications under current development.

  6. Nonequilibrium thermodynamics and fluctuation relations for small systems

    International Nuclear Information System (INIS)

    Cao Liang; Ke Pu; Qiao Li-Yan; Zheng Zhi-Gang

    2014-01-01

    In this review, we give a retrospect of the recent progress in nonequilibrium statistical mechanics and thermodynamics in small dynamical systems. For systems with only a few number of particles, fluctuations and nonlinearity become significant and contribute to the nonequilibrium behaviors of the systems, hence the statistical properties and thermodynamics should be carefully studied. We review recent developments of this topic by starting from the Gallavotti—Cohen fluctuation theorem, and then to the Evans—Searles transient fluctuation theorem, Jarzynski free-energy equality, and the Crooks fluctuation relation. We also investigate the nonequilibrium free energy theorem for trajectories involving changes of the heat bath temperature and propose a generalized free-energy relation. It should be noticed that the non-Markovian property of the heat bath may lead to the violation of the free-energy relation. (topical review - statistical physics and complex systems)

  7. Developing Large-Scale Bayesian Networks by Composition: Fault Diagnosis of Electrical Power Systems in Aircraft and Spacecraft

    Science.gov (United States)

    Mengshoel, Ole Jakob; Poll, Scott; Kurtoglu, Tolga

    2009-01-01

    This CD contains files that support the talk (see CASI ID 20100021404). There are 24 models that relate to the ADAPT system and 1 Excel worksheet. In the paper an investigation into the use of Bayesian networks to construct large-scale diagnostic systems is described. The high-level specifications, Bayesian networks, clique trees, and arithmetic circuits representing 24 different electrical power systems are described in the talk. The data in the CD are the models of the 24 different power systems.

  8. Small reactor power systems for manned planetary surface bases

    Energy Technology Data Exchange (ETDEWEB)

    Bloomfield, H.S.

    1987-12-01

    A preliminary feasibility study of the potential application of small nuclear reactor space power systems to manned planetary surface base missions was conducted. The purpose of the study was to identify and assess the technology, performance, and safety issues associated with integration of reactor power systems with an evolutionary manned planetary surface exploration scenario. The requirements and characteristics of a variety of human-rated modular reactor power system configurations selected for a range of power levels from 25 kWe to hundreds of kilowatts is described. Trade-off analyses for reactor power systems utilizing both man-made and indigenous shielding materials are provided to examine performance, installation and operational safety feasibility issues. The results of this study have confirmed the preliminary feasibility of a wide variety of small reactor power plant configurations for growth oriented manned planetary surface exploration missions. The capability for power level growth with increasing manned presence, while maintaining safe radiation levels, was favorably assessed for nominal 25 to 100 kWe modular configurations. No feasibility limitations or technical barriers were identified and the use of both distance and indigenous planetary soil material for human rated radiation shielding were shown to be viable and attractive options.

  9. Advanced Microelectronics Technologies for Future Small Satellite Systems

    Science.gov (United States)

    Alkalai, Leon

    1999-01-01

    Future small satellite systems for both Earth observation as well as deep-space exploration are greatly enabled by the technological advances in deep sub-micron microelectronics technologies. Whereas these technological advances are being fueled by the commercial (non-space) industries, more recently there has been an exciting new synergism evolving between the two otherwise disjointed markets. In other words, both the commercial and space industries are enabled by advances in low-power, highly integrated, miniaturized (low-volume), lightweight, and reliable real-time embedded systems. Recent announcements by commercial semiconductor manufacturers to introduce Silicon On Insulator (SOI) technology into their commercial product lines is driven by the need for high-performance low-power integrated devices. Moreover, SOI has been the technology of choice for many space semiconductor manufacturers where radiation requirements are critical. This technology has inherent radiation latch-up immunity built into the process, which makes it very attractive to space applications. In this paper, we describe the advanced microelectronics and avionics technologies under development by NASA's Deep Space Systems Technology Program (also known as X2000). These technologies are of significant benefit to both the commercial satellite as well as the deep-space and Earth orbiting science missions. Such a synergistic technology roadmap may truly enable quick turn-around, low-cost, and highly capable small satellite systems for both Earth observation as well as deep-space missions.

  10. Small reactor power systems for manned planetary surface bases

    International Nuclear Information System (INIS)

    Bloomfield, H.S.

    1987-12-01

    A preliminary feasibility study of the potential application of small nuclear reactor space power systems to manned planetary surface base missions was conducted. The purpose of the study was to identify and assess the technology, performance, and safety issues associated with integration of reactor power systems with an evolutionary manned planetary surface exploration scenario. The requirements and characteristics of a variety of human-rated modular reactor power system configurations selected for a range of power levels from 25 kWe to hundreds of kilowatts is described. Trade-off analyses for reactor power systems utilizing both man-made and indigenous shielding materials are provided to examine performance, installation and operational safety feasibility issues. The results of this study have confirmed the preliminary feasibility of a wide variety of small reactor power plant configurations for growth oriented manned planetary surface exploration missions. The capability for power level growth with increasing manned presence, while maintaining safe radiation levels, was favorably assessed for nominal 25 to 100 kWe modular configurations. No feasibility limitations or technical barriers were identified and the use of both distance and indigenous planetary soil material for human rated radiation shielding were shown to be viable and attractive options

  11. Workshop in a Box: Sustainable Management of Rural and Small Water and Wastewater Systems Workshops

    Science.gov (United States)

    A resource to help rural and small systems and communities to conduct workshops, either for an individual system or for a group of systems, based on the Rural and Small Systems Guidebook to Sustainable Utility Management.

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

    Science.gov (United States)

    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.

  13. Modeling and Analysis of Realistic Fire Scenarios in Spacecraft

    Science.gov (United States)

    Brooker, J. E.; Dietrich, D. L.; Gokoglu, S. A.; Urban, D. L.; Ruff, G. A.

    2015-01-01

    An accidental fire inside a spacecraft is an unlikely, but very real emergency situation that can easily have dire consequences. While much has been learned over the past 25+ years of dedicated research on flame behavior in microgravity, a quantitative understanding of the initiation, spread, detection and extinguishment of a realistic fire aboard a spacecraft is lacking. Virtually all combustion experiments in microgravity have been small-scale, by necessity (hardware limitations in ground-based facilities and safety concerns in space-based facilities). Large-scale, realistic fire experiments are unlikely for the foreseeable future (unlike in terrestrial situations). Therefore, NASA will have to rely on scale modeling, extrapolation of small-scale experiments and detailed numerical modeling to provide the data necessary for vehicle and safety system design. This paper presents the results of parallel efforts to better model the initiation, spread, detection and extinguishment of fires aboard spacecraft. The first is a detailed numerical model using the freely available Fire Dynamics Simulator (FDS). FDS is a CFD code that numerically solves a large eddy simulation form of the Navier-Stokes equations. FDS provides a detailed treatment of the smoke and energy transport from a fire. The simulations provide a wealth of information, but are computationally intensive and not suitable for parametric studies where the detailed treatment of the mass and energy transport are unnecessary. The second path extends a model previously documented at ICES meetings that attempted to predict maximum survivable fires aboard space-craft. This one-dimensional model implies the heat and mass transfer as well as toxic species production from a fire. These simplifications result in a code that is faster and more suitable for parametric studies (having already been used to help in the hatch design of the Multi-Purpose Crew Vehicle, MPCV).

  14. Development of a system model for advanced small modular reactors.

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Tom Goslee,; Holschuh, Thomas Vernon,

    2014-01-01

    This report describes a system model that can be used to analyze three advance small modular reactor (SMR) designs through their lifetime. Neutronics of these reactor designs were evaluated using Monte Carlo N-Particle eXtended (MCNPX/6). The system models were developed in Matlab and Simulink. A major thrust of this research was the initial scoping analysis of Sandias concept of a long-life fast reactor (LLFR). The inherent characteristic of this conceptual design is to minimize the change in reactivity over the lifetime of the reactor. This allows the reactor to operate substantially longer at full power than traditional light water reactors (LWRs) or other SMR designs (e.g. high temperature gas reactor (HTGR)). The system model has subroutines for lifetime reactor feedback and operation calculations, thermal hydraulic effects, load demand changes and a simplified SCO2 Brayton cycle for power conversion.

  15. Modeling and Parameter Estimation of a Small Wind Generation System

    Directory of Open Access Journals (Sweden)

    Carlos A. Ramírez Gómez

    2013-11-01

    Full Text Available The modeling and parameter estimation of a small wind generation system is presented in this paper. The system consists of a wind turbine, a permanent magnet synchronous generator, a three phase rectifier, and a direct current load. In order to estimate the parameters wind speed data are registered in a weather station located in the Fraternidad Campus at ITM. Wind speed data were applied to a reference model programed with PSIM software. From that simulation, variables were registered to estimate the parameters. The wind generation system model together with the estimated parameters is an excellent representation of the detailed model, but the estimated model offers a higher flexibility than the programed model in PSIM software.

  16. Research of pneumatic control transmission system for small irradiation samples

    International Nuclear Information System (INIS)

    Bai Zhongxiong; Zhang Haibing; Rong Ru; Zhang Tao

    2008-01-01

    In order to reduce the absorbed dose damage for the operator, pneumatic control has been adopted to realize the rapid transmission of small irradiation samples. On/off of pneumatic circuit and directions for the rapid transmission system are controlled by the electrical control part. The main program initializes the system and detects the location of the manual/automatic change-over switch, and call for the corresponding subprogram to achieve the automatic or manual operation. Automatic subprogram achieves the automatic sample transmission; Manual subprogram completes the deflation, and back and forth movement of the radiation samples. This paper introduces in detail the implementation of the system, in terms of both hardware and software design. (authors)

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

    Science.gov (United States)

    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.

  18. COCAP: a carbon dioxide analyser for small unmanned aircraft systems

    Science.gov (United States)

    Kunz, Martin; Lavric, Jost V.; Gerbig, Christoph; Tans, Pieter; Neff, Don; Hummelgård, Christine; Martin, Hans; Rödjegård, Henrik; Wrenger, Burkhard; Heimann, Martin

    2018-03-01

    Unmanned aircraft systems (UASs) could provide a cost-effective way to close gaps in the observation of the carbon cycle, provided that small yet accurate analysers are available. We have developed a COmpact Carbon dioxide analyser for Airborne Platforms (COCAP). The accuracy of COCAP's carbon dioxide (CO2) measurements is ensured by calibration in an environmental chamber, regular calibration in the field and by chemical drying of sampled air. In addition, the package contains a lightweight thermal stabilisation system that reduces the influence of ambient temperature changes on the CO2 sensor by 2 orders of magnitude. During validation of COCAP's CO2 measurements in simulated and real flights we found a measurement error of 1.2 µmol mol-1 or better with no indication of bias. COCAP is a self-contained package that has proven well suited for the operation on board small UASs. Besides carbon dioxide dry air mole fraction it also measures air temperature, humidity and pressure. We describe the measurement system and our calibration strategy in detail to support others in tapping the potential of UASs for atmospheric trace gas measurements.

  19. Integration of Small Solar tower Systems into Distributed Power Islands

    Energy Technology Data Exchange (ETDEWEB)

    Romero, M.; Marcos, M. J.; Tellez, F. M.; Blanco, M.; Fernandez, V.; Baonza, F.; Berger, S. [Ciemat, Madrid (Spain)

    2000-07-01

    One of the short-term priorities for renewable energies in Europe is their integration for local power supply into communities and energy islands (blocks of buildings, new neighborhoods in residential areas, shopping centers, hospitals, recreational areas, eco-paks, small rural areas or isolated ones such as islands or mountain communities). Following this strategy, the integration of small tower fields into so-called MIUS (Modular Integrated Utility Systems) is proposed. This application strongly influences field concepts leadings to modular multi-tower systems able to more closely track demand, meet reliability requirements with fewer megawatts of installed power and spread construction costs over time after output has begum. In addition, integration into single-cycle high-efficiency gas turbines plus waste-heat applications clearly increments the solar share. The chief questions are whether solar towers can be redesigned for such distributed markets and the keys to their feasibility. This paper includes the design and performance analysis of a 1.36-MW plant and integration in the MIUS system, as well as the expected cost of electricity and a sensitivity analysis of the small tower plant's performance with design parameters like heliostat configuration and tower height. A practical application is analyzed for a shopping center with 85% power demand during day-time by using a hybrid solar tower and a gas turbine producing electricity and waste heat for hot water and heating and cooling of spaces. The operation mode proposed is covering night demand with power from the grid and solar-gas power island mode during 14 hours daytime with a maximum power production of 1.36 MW. (Author) 26 refs.

  20. Integration of Small Solar Tower Systems Into Distributed Power Islands

    International Nuclear Information System (INIS)

    Romero, M.; Marcos, M. J.; Tellez, F. M.; Blanco, M.; Fernandez, V.; Baonza, F.; Berger, S.

    1999-01-01

    One of the short-term priorities for renewable energies in Europe is their integration for local power supply into communities and energy islands (blocks of buildings, new neighborhoods in residential areas, shopping centers, hospitals, recreational areas, eco-parks, small rural areas or isolated ones such as islands or mountain communities). Following this strategy, the integration of small tower fields into so-called MIUS (Modular Integrated Utility Systems) is proposed. This application strongly influences field concepts leading to modular multi-tower systems able to more closely track demand, meet reliability requirements with fewer megawatts of installed power and spread construction costs over time after output has begun. In addition, integration into single-cycle high-efficiency gas turbines plus waste-heat applications clearly increments the solar share. The chief questions are whether solar towers can be redesigned for such distributed markets and the keys to their feasibility. This paper includes the design and performance analysis of a 1.36-MW plant and integration in the MIUS system, as well as the expected cost of electricity and a sensitivity analysis of the small tower plant's performance with design parameters like heliostats configuration and tower height. A practical application is analyzed for a shopping center with 85% power demand during day-time by using a hybrid solar tower and a gas turbine producing electricity and waste heat for hot water and heating and cooling of spaces. The operation mode proposed is covering night demand with power from the grid and solar-gas power island mode during 14 hours daytime with a maximum power production of 1.36 MW. (Author) 26 refs

  1. Thermodynamic comparison of three small-scale gas liquefaction systems

    DEFF Research Database (Denmark)

    Nguyen, Tuong-Van; Rothuizen, Erasmus Damgaard; Markussen, Wiebke Brix

    2017-01-01

    . The present work investigates three configurations suitable for small-scale applications because of their simplicity and compactness: the single-mixed refrigerant, single and dual reverse Brayton cycles. The impact of different feed compositions and refrigerant properties is analysed. A detailed assessment...... to be more efficient (1000-2000 kJ/kgLNG) than expander-based ones (2500-5000 kJ/kgLNG) over larger ranges of operating conditions, at the expense of a greater system complexity and higher thermal conductance (250-500kW/K against 80-160 kW/K). The results show that the use of different thermodynamic models...

  2. Small Aircraft Transportation System, Higher Volume Operations Concept: Normal Operations

    Science.gov (United States)

    Abbott, Terence S.; Jones, Kenneth M.; Consiglio, Maria C.; Williams, Daniel M.; Adams, Catherine A.

    2004-01-01

    This document defines the Small Aircraft Transportation System (SATS), Higher Volume Operations (HVO) concept for normal conditions. In this concept, a block of airspace would be established around designated non-towered, non-radar airports during periods of poor weather. Within this new airspace, pilots would take responsibility for separation assurance between their aircraft and other similarly equipped aircraft. Using onboard equipment and procedures, they would then approach and land at the airport. Departures would be handled in a similar fashion. The details for this operational concept are provided in this document.

  3. Simulation of an advanced small aperture track system

    Science.gov (United States)

    Williams, Tommy J.; Crockett, Gregg A.; Brunson, Richard L.; Beatty, Brad; Zahirniak, Daniel R.; Deuto, Bernard G.

    2001-08-01

    Simulation development for EO Systems has progressed to new levels with the advent of COTS software tools such as Matlab/Simulink. These tools allow rapid reuse of simulation library routines. We have applied these tools to newly emerging Acquisition Tracking and Pointing (ATP) systems using many routines developed through a legacy to High Energy Laser programs such as AirBorne Laser, Space Based Laser, Tactical High Energy Laser, and The Air Force Research Laboratory projects associated with the Starfire Optical Range. The simulation architecture allows ease in testing various track algorithms under simulated scenes with the ability to rapidly vary system hardware parameters such as track sensor and track loop control systems. The atmospheric turbulence environment and associated optical distortion is simulated to high fidelity levels through the application of an atmospheric phase screen model to produce scintillation of the laser illuminator uplink. The particular ATP system simulated is a small transportable system for tracking satellites in a daytime environment and projects a low power laser and receives laser return from retro-reflector equipped satellites. The primary application of the ATP system (and therefore the simulation) is the determination of the illuminator beam profile, jitter, and scintillation of the low power laser at the satellite. The ATP system will serve as a test bed for satellite tracking in a high background during daytime. Of particular interest in this simulation is the ability to emulate the hardware modelogic within the simulation to test and refine system states and mode change decisions. Additionally, the simulation allows data from the hardware system tests to be imported into Matlab and to thereby drive the simulation or to be easily compared to simulation results.

  4. Simulation of the ATLAS New Small Wheel (NSW) System

    CERN Document Server

    Maekawa, Koki; The ATLAS collaboration

    2017-01-01

    The instantaneous luminosity of the Large Hadron Collider (LHC) at CERN will be increased up to a factor of five with respect to the present design value by undergoing an extensive upgrade program over the coming decade. In order to benefit from the expected high luminosity performance that will be provided by the Phase-1 upgraded LHC, the first station of the ATLAS muon end-cap Small Wheel system will need to be replaced by a New Small Wheel (NSW) detector. The NSW is going to be installed in the ATLAS detector in the forward region of 1.3 < |η| < 2.7 during the second long LHC shutdown. The NSW will have to operate in a high background radiation region, while reconstructing muon tracks with high precision as well as furnishing information for the Level-1 trigger. A detailed study of the final design and validation of the readout electronics for a set of precision tracking (Micromegas) and trigger chambers (small-strip Thin Gap Chambers or sTGC) that are able to work at high rates with excellent real-...

  5. Characterizing Biological Closed-Loop Life Support Systems for Thermal Control and Revitalization of Spacecraft Cabin Environments

    Data.gov (United States)

    National Aeronautics and Space Administration — Environmental Control and Support Systems (ECLSS) are required for all manned spaceflight missions to provide the most fundamental physiological needs. One of these...

  6. Numerical and experimental analysis of a thin liquid film on a rotating disk related to development of a spacecraft absorption cooling system

    Science.gov (United States)

    Faghri, Amir; Swanson, Theodore D.

    1989-01-01

    The numerical and experimental analysis of a thin liquid film on a rotating and a stationary disk related to the development of an absorber unit for a high capacity spacecraft absorption cooling system, is described. The creation of artificial gravity by the use of a centrifugal field was focused upon in this report. Areas covered include: (1) One-dimensional computation of thin liquid film flows; (2) Experimental measurement of film height and visualization of flow; (3) Two-dimensional computation of the free surface flow of a thin liquid film using a pressure optimization method; (4) Computation of heat transfer in two-dimensional thin film flow; (5) Development of a new computational methodology for the free surface flows using a permeable wall; (6) Analysis of fluid flow and heat transfer in a thin film in the presence and absence of gravity; and (7) Comparison of theoretical prediction and experimental data. The basic phenomena related to fluid flow and heat transfer on rotating systems reported here can also be applied to other areas of space systems.

  7. Supervisory Control System Architecture for Advanced Small Modular Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Cetiner, Sacit M [ORNL; Cole, Daniel L [University of Pittsburgh; Fugate, David L [ORNL; Kisner, Roger A [ORNL; Melin, Alexander M [ORNL; Muhlheim, Michael David [ORNL; Rao, Nageswara S [ORNL; Wood, Richard Thomas [ORNL

    2013-08-01

    This technical report was generated as a product of the Supervisory Control for Multi-Modular SMR Plants project within the Instrumentation, Control and Human-Machine Interface technology area under the Advanced Small Modular Reactor (SMR) Research and Development Program of the U.S. Department of Energy. The report documents the definition of strategies, functional elements, and the structural architecture of a supervisory control system for multi-modular advanced SMR (AdvSMR) plants. This research activity advances the state-of-the art by incorporating decision making into the supervisory control system architectural layers through the introduction of a tiered-plant system approach. The report provides a brief history of hierarchical functional architectures and the current state-of-the-art, describes a reference AdvSMR to show the dependencies between systems, presents a hierarchical structure for supervisory control, indicates the importance of understanding trip setpoints, applies a new theoretic approach for comparing architectures, identifies cyber security controls that should be addressed early in system design, and describes ongoing work to develop system requirements and hardware/software configurations.

  8. Salary Management System for Small and Medium-sized Enterprises

    Science.gov (United States)

    Hao, Zhang; Guangli, Xu; Yuhuan, Zhang; Yilong, Lei

    Small and Medium-sized Enterprises (SMEs) in the process of wage entry, calculation, the total number are needed to be done manually in the past, the data volume is quite large, processing speed is low, and it is easy to make error, which is resulting in low efficiency. The main purpose of writing this paper is to present the basis of salary management system, establish a scientific database, the computer payroll system, using the computer instead of a lot of past manual work in order to reduce duplication of staff labor, it will improve working efficiency.This system combines the actual needs of SMEs, through in-depth study and practice of the C/S mode, PowerBuilder10.0 development tools, databases and SQL language, Completed a payroll system needs analysis, database design, application design and development work. Wages, departments, units and personnel database file are included in this system, and have data management, department management, personnel management and other functions, through the control and management of the database query, add, delete, modify, and other functions can be realized. This system is reasonable design, a more complete function, stable operation has been tested to meet the basic needs of the work.

  9. Large-Scale Spacecraft Fire Safety Tests

    Science.gov (United States)

    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

  10. Embedded Thermal Control for Spacecraft Subsystems Miniaturization

    Science.gov (United States)

    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.

  11. Systems engineering and the licensing of Small Modular Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kulesa, T., E-mail: tkulesa@us.ibm.com [IBM, Philidelphia, Pennsylvania (United States); Soderholm, K., E-mail: Kristiina.Soderholm@fortum.com [Fortum Power (Finland); Fechtelkotter, P., E-mail: pfech@us.ibm.com [IBM, Boston, Massacheusets (United States)

    2014-07-01

    Both global warming and the need for dependable sources of energy continue to make nuclear power generation an appealing option. But a history of cost overruns, project delays, and environmental disaster has pushed the industry to innovate and design a more flexible, scalable, and safe source of nuclear energy - the small modular reactor. Innovation in generation technology creates disruption in already complex licensing and regulatory processes. This paper discusses how the application of systems engineering and requirements management can help combat confusion, rework, and efficiency problems across the engineering and compliance life cycle. The paper is based on the PhD Dissertation 'Licensing Model Development for Small Modular Reactors (SMRs) - Focusing on Finnish Regulatory Framework', approved in 2013. The result of the study gives recommendations and tools to develop and optimize the licensing process for SMRs. The most important SMR-specific feature, in terms of licensing, is the modularity of the design. Here the modularity indicates multi-module SMR designs, which creates new challenges in the licensing process. Another feature impacting licensing feasibility is the plan to build many standardized power plants in series and use factory-fabricated modules to optimize the construction costs. SMR licensing challenges are under discussion in many international forums, such as World Nuclear Association Cooperation in Reactor Design Evaluation and Licensing Small Modular Reactor group (WNA CORDEL SMR) group and IAEA INPRO regulators' forum. This paper also presents an application of the new licensing process using Systems Engineering, Requirements Management, and Project Management practices and tools. (author)

  12. Small invasive colon cancer with systemic metastasis: A case report

    Directory of Open Access Journals (Sweden)

    Sakamoto Taku

    2011-05-01

    Full Text Available ABSTRACT Background Recently, especially in Japan, several researchers have suggested that colorectal cancer can develop not only through an adenoma-carcinoma sequence but also from normal mucosa via a de novo pathway, and that these de novo cancers have more aggressive malignant potential. We report a case of aggressive colon cancer resulting in systemic metastasis despite small tumour size. Case Presentation A 35-year-old woman presented at the referring hospital with swelling of the left cervical lymph node. Biopsy of the lymph node revealed metastatic adenocarcinoma; however, CT scan and mammography were unable to identify the site of the primary lesion. She was diagnosed with unknown primary cancer and referred to our hospital for further examination. Immunohistochemical reevaluation showed the cervical lymph node biopsy specimen to be positive for CDX2 and CK20 and negative for CK7 expression, leading us to suspect the presence of a primary colorectal cancer. We performed a total colonoscopy, and detected a small protruding lesion in the transverse colon. The tumour was only 12 mm in diameter, with a central depressed component and a severely thickened stalk, which suggested direct cancer invasion of the deep submucosa. We concluded that this lesion was the site of origin of the metastasis despite the small tumour size, and performed diagnostic endoscopic mucosal resection. The lesion was found to have an intramucosal cancer component, demonstrating that this lesion represented primary colon cancer. The patient was referred to the gastrointestinal oncology division for systemic chemotherapy. Conclusions In this case, immunohistochemical findings strongly suggested the existence of a colorectal cancer. The non-polypoid gross appearance of the tumour suggested that it can originate de novo , thus providing a valuable case in support of the aggressive malignant potential of a de novo colorectal cancer pathway.

  13. Systems engineering and the licensing of Small Modular Reactors

    International Nuclear Information System (INIS)

    Kulesa, T.; Soderholm, K.; Fechtelkotter, P.

    2014-01-01

    Both global warming and the need for dependable sources of energy continue to make nuclear power generation an appealing option. But a history of cost overruns, project delays, and environmental disaster has pushed the industry to innovate and design a more flexible, scalable, and safe source of nuclear energy - the small modular reactor. Innovation in generation technology creates disruption in already complex licensing and regulatory processes. This paper discusses how the application of systems engineering and requirements management can help combat confusion, rework, and efficiency problems across the engineering and compliance life cycle. The paper is based on the PhD Dissertation 'Licensing Model Development for Small Modular Reactors (SMRs) - Focusing on Finnish Regulatory Framework', approved in 2013. The result of the study gives recommendations and tools to develop and optimize the licensing process for SMRs. The most important SMR-specific feature, in terms of licensing, is the modularity of the design. Here the modularity indicates multi-module SMR designs, which creates new challenges in the licensing process. Another feature impacting licensing feasibility is the plan to build many standardized power plants in series and use factory-fabricated modules to optimize the construction costs. SMR licensing challenges are under discussion in many international forums, such as World Nuclear Association Cooperation in Reactor Design Evaluation and Licensing Small Modular Reactor group (WNA CORDEL SMR) group and IAEA INPRO regulators' forum. This paper also presents an application of the new licensing process using Systems Engineering, Requirements Management, and Project Management practices and tools. (author)

  14. Quarkonia production in small and large systems measured by ATLAS

    CERN Document Server

    Lopez, Jorge; The ATLAS collaboration

    2018-01-01

    The experimentally observed dissociation and regeneration of bound quarkonium states in heavy-ion collisions provide a powerful tool to probe the dynamics of the hot, dense plasma. These measurements are sensitive to the effects of color screening, color recombination, or other, new suppression mechanisms. In the large-statistics Run 2 lead-lead and proton-lead collision data, these phenomena can be probed with unprecedented precision. Measurements of the ground and excited quarkonia states, as well as their separation into prompt and non-prompt components, provide further opportunities to study the dynamics of heavy parton energy loss in these large systems. In addition, quarkonium production rates, and their excited to ground states ratios, in small, asymmetric systems are an interesting probe of cold nuclear matter effects. In this talk, the latest ATLAS results on quarkonia production will be presented, including new, differential measurements of charmonium suppression and azimuthal modulation in lead-lea...

  15. Irradiation system for neutron capture therapy using the small accelerator

    International Nuclear Information System (INIS)

    Kobayashi, Tooru; Hoshi, Masaharu

    2002-01-01

    Neutron capture therapy (NCT) is to kill tumor cells that previously incorporated the stable isotope which generates heavy charged particles with a short range and a high linear energy transfer (LET) on neutron irradiation. Boron-10 is ordinarily used as such an isotope. The tumor tissue is neutron-irradiated at craniotomy after preceding craniotomy for tumor extraction: therefore two surgeries are required for the present NCT in Japan. The reactions 10 B(n, αγ) 7 Li and 7 Li (p, n) 7 Be are thought preferential for patients and doctors if a convenient small accelerator, not the reactor used at present, is available in the hospital because only one craniotomy is sufficient. Authors' examinations of the system for NCT using the small accelerator involve irradiation conditions, desirable energy spectrum of neutron, characterization of thermal and epi-thermal neutrons, social, practical and technical comparison of the reactor and accelerator, and usefulness of the reaction 7 Li (p, n) 7 Be. The system devoted to the NCT is awaited in future. (K.H.)

  16. Framework for continuous performance improvement in small drinking water systems.

    Science.gov (United States)

    Bereskie, Ty; Haider, Husnain; Rodriguez, Manuel J; Sadiq, Rehan

    2017-01-01

    Continuous performance improvement (CPI) can be a useful approach to overcome water quality problems impacting small communities. Small drinking water systems (SDWSs) struggle to meet regulatory requirements and often lack the economic and human resource flexibility for immediate improvement. A CPI framework is developed to provide SDWS managers and operators an approach to gauge their current performance against similar systems and to track performance improvement from the implementation of the new technologies or innovations into the future. The proposed CPI framework incorporates the use of a water quality index (WQI) and functional performance benchmarking to evaluate and compare drinking water quality performance of an individual water utility against that of a representative benchmark. The results are then used to identify and prioritize the most vulnerable water quality indicators and subsequently identify and prioritize performance improvement strategies. The proposed CPI framework has been demonstrated using data collected from SDWSs in the province of Newfoundland and Labrador (NL), Canada and using the Canadian Council of Ministers of the Environment (CCME) WQI. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Small-Molecule Inhibitors of the Type III Secretion System

    Directory of Open Access Journals (Sweden)

    Lingling Gu

    2015-09-01

    Full Text Available Drug-resistant pathogens have presented increasing challenges to the discovery and development of new antibacterial agents. The type III secretion system (T3SS, existing in bacterial chromosomes or plasmids, is one of the most complicated protein secretion systems. T3SSs of animal and plant pathogens possess many highly conserved main structural components comprised of about 20 proteins. Many Gram-negative bacteria carry T3SS as a major virulence determinant, and using the T3SS, the bacteria secrete and inject effector proteins into target host cells, triggering disease symptoms. Therefore, T3SS has emerged as an attractive target for antimicrobial therapeutics. In recent years, many T3SS-targeting small-molecule inhibitors have been discovered; these inhibitors prevent the bacteria from injecting effector proteins and from causing pathophysiology in host cells. Targeting the virulence of Gram-negative pathogens, rather than their survival, is an innovative and promising approach that may greatly reduce selection pressures on pathogens to develop drug-resistant mutations. This article summarizes recent progress in the search for promising small-molecule T3SS inhibitors that target the secretion and translocation of bacterial effector proteins.

  18. Deployable Propulsion, Power and Communications Systems for Solar System Exploration

    Science.gov (United States)

    Johnson, L.; Carr, J.; Boyd, D.

    2017-01-01

    NASA is developing thin-film based, deployable propulsion, power, and communication systems for small spacecraft that could provide a revolutionary new capability allowing small spacecraft exploration of the solar system. By leveraging recent advancements in thin films, photovoltaics, and miniaturized electronics, new mission-level capabilities will be enabled aboard lower-cost small spacecraft instead of their more expensive, traditional counterparts, enabling a new generation of frequent, inexpensive deep space missions. Specifically, thin-film technologies are allowing the development and use of solar sails for propulsion, small, lightweight photovoltaics for power, and omnidirectional antennas for communication.

  19. Small Stirling dynamic isotope power system for robotic space missions

    International Nuclear Information System (INIS)

    Bents, D.J.

    1992-08-01

    The design of a multihundred-watt Dynamic Isotope Power System (DIPS), based on the US Department of Energy (DOE) General Purpose Heat Source (GPHS) and small (multihundred-watt) free-piston Stirling engine (FPSE), is being pursued as a potential lower cost alternative to radioisotope thermoelectric generators (RTG's). The design is targeted at the power needs of future unmanned deep space and planetary surface exploration missions ranging from scientific probes to Space Exploration Initiative precursor missions. Power level for these missions is less than a kilowatt. The incentive for any dynamic system is that it can save fuel and reduce costs and radiological hazard. Unlike DIPS based on turbomachinery conversion (e.g. Brayton), this small Stirling DIPS can be advantageously scaled to multihundred-watt unit size while preserving size and mass competitiveness with RTG's. Stirling conversion extends the competitive range for dynamic systems down to a few hundred watts--a power level not previously considered for dynamic systems. The challenge for Stirling conversion will be to demonstrate reliability and life similar to RTG experience. Since the competitive potential of FPSE as an isotope converter was first identified, work has focused on feasibility of directly integrating GPHS with the Stirling heater head. Thermal modeling of various radiatively coupled heat source/heater head geometries has been performed using data furnished by the developers of FPSE and GPHS. The analysis indicates that, for the 1050 K heater head configurations considered, GPHS fuel clad temperatures remain within acceptable operating limits. Based on these results, preliminary characterizations of multihundred-watt units have been established

  20. Small Radioisotope Power System Testing at NASA Glenn Research Center

    Science.gov (United States)

    Dugala, Gina; Bell, Mark; Oriti, Salvatore; Fraeman, Martin; Frankford, David; Duven, Dennis

    2013-01-01

    In April 2009, NASA Glenn Research Center (GRC) formed an integrated product team (IPT) to develop a Small Radioisotope Power System (SRPS) utilizing a single Advanced Stirling Convertor (ASC) with passive balancer. A single ASC produces approximately 80 We making this system advantageous for small distributed lunar science stations. The IPT consists of Sunpower, Inc., to provide the single ASC with a passive balancer, The Johns Hopkins University Applied Physics Laboratory (JHUAPL) to design an engineering model Single Convertor Controller (SCC) for an ASC with a passive balancer, and NASA GRC to provide technical support to these tasks and to develop a simulated lunar lander test stand. The single ASC with a passive balancer, simulated lunar lander test stand, and SCC were delivered to GRC and were tested as a system. The testing sequence at GRC included SCC fault tolerance, integration, electromagnetic interference (EMI), vibration, and extended operation testing. The SCC fault tolerance test characterized the SCCs ability to handle various fault conditions, including high or low bus power consumption, total open load or short circuit, and replacing a failed SCC card while the backup maintains control of the ASC. The integrated test characterized the behavior of the system across a range of operating conditions, including variations in cold-end temperature and piston amplitude, including the emitted vibration to both the sensors on the lunar lander and the lunar surface. The EMI test characterized the AC and DC magnetic and electric fields emitted by the SCC and single ASC. The vibration test confirms the SCCs ability to control the single ASC during launch. The extended operation test allows data to be collected over a period of thousands of hours to obtain long term performance data of the ASC with a passive balancer and the SCC. This paper will discuss the results of each of these tests.

  1. Redesigning a collection system for 'small' consumer electronics

    International Nuclear Information System (INIS)

    Melissen, Frans W.

    2006-01-01

    This paper establishes that the collection system within the recycling scheme for consumer electronics in the Netherlands has not been entirely successful in convincing consumers to hand in their used appliances by means of dedicated collection routes. Particularly regarding small appliances, consumers are persisting in their habit of discarding their appliances by means of the refuse bag/bin for regular household waste. Therefore, the current collection system has been unable to direct consumer behavior in the desired direction. Consequently, the layout of the current system is reviewed and redesigned in order to tackle this problem. This design effort applies the Triad model (behavioral model) in the analysis stage and the Morphological Chart method (design tool) in the synthesis stage, and results in a concrete proposal for a new system. Finally, the applicability of this design approach beyond the specific circumstances of the case study presented in this paper is discussed. This case represents only one example of the broader, worldwide challenge to design appropriate collection systems to direct consumer behavior in desired directions. It is argued that the approach presented in this paper could be a valuable contribution to research dealing with this challenge

  2. Fault Diagnosis Scheme for Nonlinear Stochastic Systems with Time-Varying Fault: Application to the Rigid Spacecraft Control

    Czech Academy of Sciences Publication Activity Database

    Nguyen, H.Q.; Čelikovský, Sergej

    2012-01-01

    Roč. 1, č. 3 (2012), s. 179-187 ISSN 2223-7038 R&D Projects: GA ČR(CZ) GAP103/12/1794 Institutional support: RVO:67985556 Keywords : Attitude control * adaptive fault estimation * LMI * PDF Subject RIV: BC - Control Systems Theory http://lib.physcon.ru/doc?id=02c925f7e4ab

  3. Printable Spacecraft: Flexible Electronic Platforms for NASA Missions. Phase One

    Science.gov (United States)

    Short, Kendra (Principal Investigator); Van Buren, David (Principal Investigator)

    2012-01-01

    Atmospheric confetti. Inchworm crawlers. Blankets of ground penetrating radar. These are some of the unique mission concepts which could be enabled by a printable spacecraft. Printed electronics technology offers enormous potential to transform the way NASA builds spacecraft. A printed spacecraft's low mass, volume and cost offer dramatic potential impacts to many missions. Network missions could increase from a few discrete measurements to tens of thousands of platforms improving areal density and system reliability. Printed platforms could be added to any prime mission as a low-cost, minimum resource secondary payload to augment the science return. For a small fraction of the mass and cost of a traditional lander, a Europa flagship mission might carry experimental printed surface platforms. An Enceladus Explorer could carry feather-light printed platforms to release into volcanic plumes to measure composition and impact energies. The ability to print circuits directly onto a variety of surfaces, opens the possibility of multi-functional structures and membranes such as "smart" solar sails and balloons. The inherent flexibility of a printed platform allows for in-situ re-configurability for aerodynamic control or mobility. Engineering telemetry of wheel/soil interactions are possible with a conformal printed sensor tape fit around a rover wheel. Environmental time history within a sample return canister could be recorded with a printed sensor array that fits flush to the interior of the canister. Phase One of the NIAC task entitled "Printable Spacecraft" investigated the viability of printed electronics technologies for creating multi-functional spacecraft platforms. Mission concepts and architectures that could be enhanced or enabled with this technology were explored. This final report captures the results and conclusions of the Phase One study. First, the report presents the approach taken in conducting the study and a mapping of results against the proposed

  4. Development of an advanced spacecraft tandem mass spectrometer

    Science.gov (United States)

    Drew, Russell C.

    1992-03-01

    The purpose of this research was to apply current advanced technology in electronics and materials to the development of a miniaturized Tandem Mass Spectrometer that would have the potential for future development into a package suitable for spacecraft use. The mass spectrometer to be used as a basis for the tandem instrument would be a magnetic sector instrument, of Nier-Johnson configuration, as used on the Viking Mars Lander mission. This instrument configuration would then be matched with a suitable second stage MS to provide the benefits of tandem MS operation for rapid identification of unknown organic compounds. This tandem instrument is configured with a newly designed GC system to aid in separation of complex mixtures prior to MS analysis. A number of important results were achieved in the course of this project. Among them were the development of a miniaturized GC subsystem, with a unique desorber-injector, fully temperature feedback controlled oven with powered cooling for rapid reset to ambient conditions, a unique combination inlet system to the MS that provides for both membrane sampling and direct capillary column sample transfer, a compact and ruggedized alignment configuration for the MS, an improved ion source design for increased sensitivity, and a simple, rugged tandem MS configuration that is particularly adaptable to spacecraft use because of its low power and low vacuum pumping requirements. The potential applications of this research include use in manned spacecraft like the space station as a real-time detection and warning device for the presence of potentially harmful trace contaminants of the spacecraft atmosphere, use as an analytical device for evaluating samples collected on the Moon or a planetary surface, or even use in connection with monitoring potentially hazardous conditions that may exist in terrestrial locations such as launch pads, environmental test chambers or other sensitive areas. Commercial development of the technology

  5. Automating Trend Analysis for Spacecraft Constellations

    Science.gov (United States)

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

    2001-01-01

    Spacecraft trend analysis is a vital mission operations function performed by satellite controllers and engineers, who perform detailed analyses of engineering telemetry data to diagnose subsystem faults and to detect trends that may potentially lead to degraded subsystem performance or failure in the future. It is this latter function that is of greatest importance, for careful trending can often predict or detect events that may lead to a spacecraft's entry into safe-hold. Early prediction and detection of such events could result in the avoidance of, or rapid return to service from, spacecraft safing, which not only results in reduced recovery costs but also in a higher overall level of service for the satellite system. Contemporary spacecraft trending activities are manually intensive and are primarily performed diagnostically after a fault occurs, rather than proactively to predict its occurrence. They also tend to rely on information systems and software that are oudated when compared to current technologies. When coupled with the fact that flight operations teams often have limited resources, proactive trending opportunities are limited, and detailed trend analysis is often reserved for critical responses to safe holds or other on-orbit events such as maneuvers. While the contemporary trend analysis approach has sufficed for current single-spacecraft operations, it will be unfeasible for NASA's planned and proposed space science constellations. Missions such as the Dynamics, Reconnection and Configuration Observatory (DRACO), for example, are planning to launch as many as 100 'nanospacecraft' to form a homogenous constellation. A simple extrapolation of resources and manpower based on single-spacecraft operations suggests that trending for such a large spacecraft fleet will be unmanageable, unwieldy, and cost-prohibitive. It is therefore imperative that an approach to automating the spacecraft trend analysis function be studied, developed, and applied to

  6. Digital tripwire: a small automated human detection system

    Science.gov (United States)

    Fischer, Amber D.; Redd, Emmett; Younger, A. Steven

    2009-05-01

    A low cost, lightweight, easily deployable imaging sensor that can dependably discriminate threats from other activities within its field of view and, only then, alert the distant duty officer by transmitting a visual confirmation of the threat would provide a valuable asset to modern defense. At present, current solutions suffer from a multitude of deficiencies - size, cost, power endurance, but most notably, an inability to assess an image and conclude that it contains a threat. The human attention span cannot maintain critical surveillance over banks of displays constantly conveying such images from the field. DigitalTripwire is a small, self-contained, automated human-detection system capable of running for 1-5 days on two AA batteries. To achieve such long endurance, the DigitalTripwire system utilizes an FPGA designed with sleep functionality. The system uses robust vision algorithms, such as a partially unsupervised innovative backgroundmodeling algorithm, which employ several data reduction strategies to operate in real-time, and achieve high detection rates. When it detects human activity, either mounted or dismounted, it sends an alert including images to notify the command center. In this paper, we describe the hardware and software design of the DigitalTripwire system. In addition, we provide detection and false alarm rates across several challenging data sets demonstrating the performance of the vision algorithms in autonomously analyzing the video stream and classifying moving objects into four primary categories - dismounted human, vehicle, non-human, or unknown. Performance results across several challenging data sets are provided.

  7. A Bioassay System Using Bioelectric Signals from Small Fish

    Science.gov (United States)

    Terawaki, Mitsuru; Soh, Zu; Hirano, Akira; Tsuji, Toshio

    Although the quality of tap water is generally examined using chemical assay, this method cannot be used for examination in real time. Against such a background, the technique of fish bioassay has attracted attention as an approach that enables constant monitoring of aquatic contamination. The respiratory rhythms of fish are considered an efficient indicator for the ongoing assessment of water quality, since they are sensitive to chemicals and can be indirectly measured from bioelectric signals generated by breathing. In order to judge aquatic contamination accurately, it is necessary to measure bioelectric signals from fish swimming freely as well as to stably discriminate measured signals, which vary between individuals. However, no bioassay system meeting the above requirements has yet been established. This paper proposes a bioassay system using bioelectric signals generated from small fish in free-swimming conditions. The system records signals using multiple electrodes to cover the extensive measurement range required in a free-swimming environment, and automatically discriminates changes in water quality from signal frequency components. This discrimination is achieved through an ensemble classification method using probability neural networks to solve the problem of differences between individual fish. The paper also reports on the results of related validation experiments, which showed that the proposed system was able to stably discriminate between water conditions before and after bleach exposure.

  8. MODELING AND DESIGN OF INNOVATIVE SMALL DIAMETER GRAVITY SEWERAGE SYSTEM

    Directory of Open Access Journals (Sweden)

    Tadeusz Nawrot

    2017-05-01

    Full Text Available The article presents modern methods of hydraulic design of an innovative small diameter gravity sewerage system. In this system, domestic wastewater is preliminary treated in septic tanks equipped with outlet filters, thus the effluent features are similar to those of clear water. Innovative non-return valves at the outlets eliminate introduction of air to the system and thus the flows can be treated as one-phase ones. Computer codes EPANET 2 and SWMM 5.0 were applied and compared. Two flow schemes typical for the sewerage system were implemented in EPANET 2, and the third - in a slightly modified SWMM 5.0. Simulation results were validated on empirical data obtained on a laboratory physical model, consisting of four tanks of minimum volumes 600 dm3 each, connecting PE pipelines of diameters 25 mm and 36 mm and relevant sanitary fittings. Water inflows, typical for domestic wastewater outflows from single homesteads, were provided by a pump. Water flows were measured using water meters with pulse outputs, and water levels in tanks by pressure transducers. Hydraulic characteristics of filters and non-return valves were provided. Simulation results showed good agreement with the empirical data. Ranges of values of design parameters, needed for successful application of both codes, were established and discussed.

  9. Small-scale tactile graphics for virtual reality systems

    Science.gov (United States)

    Roberts, John W.; Slattery, Oliver T.; Swope, Brett; Min, Volker; Comstock, Tracy

    2002-05-01

    As virtual reality technology moves forward, there is a need to provide the user with options for greater realism for closer engagement to the human senses. Haptic systems use force feedback to create a large-scale sensation of physical interaction in a virtual environment. Further refinement can be created by using tactile graphics to reproduce a detailed sense of touch. For example, a haptic system might create the sensation of the weight of a virtual orange that the user picks up, and the sensation of pressure on the fingers as the user squeezes the orange. A tactile graphic system could create the texture of the orange on the user's fingertips. IN the real wold, a detailed sense of touch plays a large part in picking up and manipulating small objects. Our team is working to develop technology that can drive a high density fingertip array of tactile simulators at a rapid refresh rate, sufficient to produce a realistic sense of touch. To meet the project criteria, the mechanism must be much lower cost than existing technologies, and must be sufficiently lightweight and compact to permit portable use and to enable installation of the stimulator array in the fingertip of a tactile glove. The primary intended applications for this technology are accessibility for the blind and visually impaired, teleoperation, and virtual reality systems.

  10. Feasibility study of a small, thorium-based fission power system for space and terrestrial applications

    Science.gov (United States)

    Worrall, Michael Jason

    One of the current challenges facing space exploration is the creation of a power source capable of providing useful energy for the entire duration of a mission. Historically, radioisotope batteries have been used to provide load power, but this conventional system may not be capable of sustaining continuous power for longer duration missions. To remedy this, many forays into nuclear powered spacecraft have been investigated, but no robust system for long-term power generation has been found. In this study, a novel spin on the traditional fission power system that represents a potential optimum solution is presented. By utilizing mature High Temperature Gas Reactor (HTGR) technology in conjunction with the capabilities of the thorium fuel cycle, we have created a light-weight, long-term power source capable of a continuous electric power output of up to 70kW for over 15 years. This system relies upon a combination of fissile, highly-enriched uranium dioxide and fertile thorium carbide Tri-Structural Isotropic (TRISO) fuel particles embedded in a hexagonal beryllium oxide matrix. As the primary fissile material is consumed, the fertile material breeds new fissile material leading to more steady fuel loading over the lifetime of the core. Reactor control is achieved through an innovative approach to the conventional boron carbide neutron absorber by utilizing sections of borated aluminum placed in rotating control drums within the reflector. Borated aluminum allows for much smaller boron concentrations, thus eliminating the potential for 10B(n,alpha)6Li heating issues that are common in boron carbide systems. A wide range of other reactivity control systems are also investigated, such as a radially-split rotating reflector. Lastly, an extension of the design to a terrestrial based system is investigated. In this system, uranium enrichment is dropped to 20 percent in order to meet current regulations, a solid uranium-zirconium hydride fissile driver replaces the

  11. Design flow factors for sewerage systems in small arid communities

    Directory of Open Access Journals (Sweden)

    Emad H. Imam

    2014-09-01

    Full Text Available Reliable estimation of sewage flow rates is essential for the proper design of sewers, pumping stations, and treatment plants. The design of the various components of the sewerage system should be based on the most critical flow rates with a focus on extremely low and peak flow rates that would be sustained for a duration related to the acceptable limits of behavior of the components under consideration. The extreme flow conditions and to what extent they differ from the average values are closely related to the size of the community or network, and the socioeconomic conditions. A single pumping station is usually sufficient to pump flow from small community in either flat or non-undulating topography. Therefore, the hydraulic loading on the wastewater treatment plant (WWTP results from the pumped flow from the pumping station rather than the trunk sewer flow. The intermittent operation of the pumping units further accentuates the sewage hydrograph in the final trunk sewer. Accordingly, the design flow for the various components of the WWTP should be determined based on their relevant flow factors. In this study, analysis of one representative small community out of five monitored small communities in Egypt and the Kingdom of Saudi Arabia is presented. Pumped sewage flow rates were measured and the sewer incoming flows were hydraulically derived. The hourly and daily sewer and pumped flow records were analyzed to derive the relationship between the flow factors that would be sustained for various durations (instantaneously, 1 h, 2 h, etc. and their probability of non-exceedance. The resulting peaking factors with a consideration for their sustained flow duration and specified probability would permit the design of the various components of the treatment plant using more accurate critical flows.

  12. Design flow factors for sewerage systems in small arid communities.

    Science.gov (United States)

    Imam, Emad H; Elnakar, Haitham Y

    2014-09-01

    Reliable estimation of sewage flow rates is essential for the proper design of sewers, pumping stations, and treatment plants. The design of the various components of the sewerage system should be based on the most critical flow rates with a focus on extremely low and peak flow rates that would be sustained for a duration related to the acceptable limits of behavior of the components under consideration. The extreme flow conditions and to what extent they differ from the average values are closely related to the size of the community or network, and the socioeconomic conditions. A single pumping station is usually sufficient to pump flow from small community in either flat or non-undulating topography. Therefore, the hydraulic loading on the wastewater treatment plant (WWTP) results from the pumped flow from the pumping station rather than the trunk sewer flow. The intermittent operation of the pumping units further accentuates the sewage hydrograph in the final trunk sewer. Accordingly, the design flow for the various components of the WWTP should be determined based on their relevant flow factors. In this study, analysis of one representative small community out of five monitored small communities in Egypt and the Kingdom of Saudi Arabia is presented. Pumped sewage flow rates were measured and the sewer incoming flows were hydraulically derived. The hourly and daily sewer and pumped flow records were analyzed to derive the relationship between the flow factors that would be sustained for various durations (instantaneously, 1 h, 2 h, etc.) and their probability of non-exceedance. The resulting peaking factors with a consideration for their sustained flow duration and specified probability would permit the design of the various components of the treatment plant using more accurate critical flows.

  13. Relativistic Spacecraft Propelled by Directed Energy

    Science.gov (United States)

    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.

  14. The performance study of a small hydroelectric power system

    International Nuclear Information System (INIS)

    Al-Jumaily, Khalil E. J.; Tawfi, Sinan Samir

    2006-01-01

    A small hydroelectric power system of an undershot waterwheel was designed, constructed and experimented in the hydraulic channel which has a sluice gate as a small dam. The constructed waterwheel diameter could be changed from 0.4 m to 0.6 m at interval steps of 0.04 m. The number of blades of the constructed waterwheel could be changed from 9 to 12 to 18 and to 36 blades. By increasing the water mass flow rate from 0.341 to 1.765 kg/s at channel cross sectional area (12.75 cm 2 ), the undershot waterwheel generated power which increased to 0.201 Watt, the mechanical efficiency increased to more than 10.8%, and the electrical efficiency increased to more than 80.6%. But the channel efficiency was decreased to 10.9%. while the volumetric efficiency was fixed at 72.9%. The waterwheel efficiency 17.25 m 2 at fixed water mass flow rate (1.765kg/s), the undershot waterwheel generated power system decreased in the following. The generator output power from 0.201 to 0.067 Watt, the mechanical efficiency reduced to 26.7% and the electrical efficiency reduced 94.4% and increased the channel efficiency from 8.6% to 100%, the volumetric efficiency from 70.9% to 75.5%, and the waterwheel efficiency from 85.7%( to 91.3%. The transitional efficiency was fixed at 97.9%. The maximum overall efficiency of the small generated power system was 6.69% at the water head 15.45 cm. The output power was 0.18 Watt. these values obtained when the number of blades 36, number of revolutions per minute 57 rpm, waterwheel diameter 0.44 m, water mass flow rate 1.765 kg/s, and channel cross sectional area 12.75 cm 2 . The theoretical extrapolation of the waterwheel diameter to 2 m with water head of 5 m gives an output generated power of 675 Watt.(Author)

  15. Analysis of Small Aircraft as a Transportation System

    Science.gov (United States)

    Dollyhigh, Samuel M.; Yackovetsky, Robert E. (Technical Monitor)

    2002-01-01

    An analysis was conducted to examine the market viability of small aircraft as a transportation mode in competition with automobile and scheduled commercial air travel by estimating the pool of users that would potentially switch to on-demand air travel due to cost/time savings. The basis for the analysis model was the Integrated Air Transportation System Evaluation Tool (IATSET) which was developed under contract to NASA by the Logistics Management Institute. IATSET is a macroeconomic model that predicts at a National level the mode choice between automobile, scheduled air, and on-demand air travel based on the value of a travelers time and monetary cost of the trip. A number of modifications are detailed to the original IATSET to better model the changing small aircraft environment. The potential trip market was modeled for the Eclipse 500 operated as a corporate jet and as an air taxi for the business travel market. The Cirrus 20R and a $80K single engine piston aircraft (based on automobile manufacturing technology) are evaluated in the pleasure and personal business travel market.

  16. Simulation of the ATLAS New Small Wheel (NSW) System

    CERN Document Server

    Maekawa, Koki; The ATLAS collaboration

    2017-01-01

    The instantaneous luminosity of the Large Hadron Collider (LHC) at CERN will be increased up to a factor of five with respect to the present design value by undergoing an extensive upgrade program over the coming decade. In order to benefit from the expected high luminosity performance, the first station of the ATLAS muon end-cap Small Wheel system will need to be replaced by a New Small Wheel (NSW) detector during the second long LHC shutdown. The NSW will have to operate in a high background radiation region, while reconstructing muon tracks with high precision as well as furnishing information for the Level-1 trigger. The NSW simulation has been developed to model the actual response of the detector and its fast electronics. The simulation has been used to get a deep understanding of the trigger logic timing, the tracking-segment finding efficiency, track rate and track-pointing resolutions at the high background hit rate expected during the next phases of ATLAS at LHC. The results of these performance stu...

  17. Dynamical evolution of small bodies in the Solar System

    Science.gov (United States)

    Jacobson, Seth A.

    2012-05-01

    This thesis explores the dynamical evolution of small bodies in the Solar System. It focuses on the asteroid population but parts of the theory can be applied to other systems such as comets or Kuiper Belt objects. Small is a relative term that refers to bodies whose dynamics can be significantly perturbed by non-gravitational forces and tidal torques on timescales less than their lifetimes (for instance the collisional timescale in the Main Belt asteroid population or the sun impact timescale for the near-Earth asteroid population). Non-gravitational torques such as the YORP effect can result in the active endogenous evolution of asteroid systems; something that was not considered more than twenty years ago. This thesis is divided into three independent studies. The first explores the dynamics of a binary systems immediately after formation from rotational fission. The rotational fission hypothesis states that a rotationally torqued asteroid will fission when the centrifugal accelerations across the body exceed gravitational attraction. Asteroids must have very little or no tensile strength for this to occur, and are often referred to as "rubble piles.'' A more complete description of the hypothesis and the ensuing dynamics is provided there. From that study a framework of asteroid evolution is assembled. It is determined that mass ratio is the most important factor for determining the outcome of a rotational fission event. Each observed binary morphology is tied to this evolutionary schema and the relevant timescales are assessed. In the second study, the role of non-gravitational and tidal torques in binary asteroid systems is explored. Understanding the competition between tides and the YORP effect provides insight into the relative abundances of the different binary morphologies and the effect of planetary flybys. The interplay between tides and the BYORP effect creates dramatic evolutionary pathways that lead to interesting end states including stranded

  18. REQUIREMENTS FOR IMAGE QUALITY OF EMERGENCY SPACECRAFTS

    Directory of Open Access Journals (Sweden)

    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.

  19. Stability and complexity of small random linear systems

    Science.gov (United States)

    Hastings, Harold

    2010-03-01

    We explore the stability of the small random linear systems, typically involving 10-20 variables, motivated by dynamics of the world trade network and the US and Canadian power grid. This report was prepared as an account of work sponsored by an agency of the US Government. Neither the US Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the US Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the US Government or any agency thereof.

  20. Chinese National Optical Education Small Private Online Course system

    Science.gov (United States)

    Zhang, XiaoJie; Lin, YuanFang; Liu, Xu; Liu, XiangDong; Cen, ZhaoFeng; Li, XiaoTong; Zheng, XiaoDong; Wang, XiaoPing

    2017-08-01

    In order to realize the sharing of high quality course resources and promote the deep integration of `Internet+' higher education and talent training, a new on-line to off-line specialized courses teaching mode was explored in Chinese colleges and universities, which emphasized different teaching places, being organized asynchronously and localized. The latest progress of the Chinese National Optical Education Small Private On-line Course (CNOESPOC) system set up by Zhejiang University and other colleges and universities having disciplines in the field of optics and photonics under the guidance of the Chinese National Steering Committee of Optics and Photonics (CNSCOP) was introduced in this paper. The On-line to Off-line (O2O) optical education teaching resource sharing practice offers a new good example for higher education in China under the background of Internet +.

  1. Lean Gasoline System Development for Fuel Efficient Small Cars

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Stuart R. [General Motors LLC, Pontiac, MI (United States)

    2013-11-25

    The General Motors and DOE cooperative agreement program DE-EE0003379 is completed. The program has integrated and demonstrated a lean-stratified gasoline engine, a lean aftertreatment system, a 12V Stop/Start system and an Active Thermal Management system along with the necessary controls that significantly improves fuel efficiency for small cars. The fuel economy objective of an increase of 25% over a 2010 Chevrolet Malibu and the emission objective of EPA T2B2 compliance have been accomplished. A brief review of the program, summarized from the narrative is: The program accelerates development and synergistic integration of four cost competitive technologies to improve fuel economy of a light-duty vehicle by at least 25% while meeting Tier 2 Bin 2 emissions standards. These technologies can be broadly implemented across the U.S. light-duty vehicle product line between 2015 and 2025 and are compatible with future and renewable biofuels. The technologies in this program are: lean combustion, innovative passive selective catalyst reduction lean aftertreatment, 12V stop/start and active thermal management. The technologies will be calibrated in a 2010 Chevrolet Malibu mid-size sedan for final fuel economy demonstration.

  2. Comparative Analysis of Inversors for Small PV Systems Grid Connected

    International Nuclear Information System (INIS)

    Sidrach de Cardona, M.; Ramirez, L.

    2001-01-01

    The energy produced by a grid connected photovoltaic system is a function of weather conditions, mainly available radiation and temperature, photovoltaic array efficiency and inverter characteristics. The results obtained in experimental measurements with four small grid-connected inverters are described in this work. The main goal is to know the inverter performance in real operation conditions. For this purpose a 2 kW photovoltaic system has been used. These results allow us to know both the inverter efficiency and its output power quality. The following parameters have been evaluated as a function of output inverter power: efficiency, point of maximum power tracking, intensity and voltage waveform, total harmonic distortion and harmonic values to 31 order, frequency, power factor and reactive power. Other interesting parameters like stand-by energy consumption and daily losses due to the inverter threshold have also been analyzed. The results allow us to know the inverter features as a function of its real work point. In our comparative study it is possible to observe remarkable differences between the inverters; these results show how important it is to have a unique standard for inverters to photovoltaic grid-connected systems. (Author) 10 refs

  3. Nb nanoSQUIDs for detection of small spin systems

    Energy Technology Data Exchange (ETDEWEB)

    Woelbing, R.; Nagel, J.; Kemmler, M.; Kleiner, R.; Koelle, D. [Physikalisches Institut, Universitaet Tuebingen (Germany); Kieler, O.; Weimann, T.; Kohlmann, J.; Zorin, A. [Fachbereich 2.4 ' ' Quantenelektronik' ' , PTB Braunschweig (Germany); Buchter, A.; Xue, F.; Poggio, M. [Department of Physics, University of Basel (Switzerland); Rueffer, D.; Russo-Averchi, E.; Fontcuberta i Morral, A. [Laboratoire des Materiaux Semiconducteurs, EPF Lausanne (Switzerland); Huber, R.; Berberich, P. [Physik-Department E10, Technische Universitaet Muenchen (Germany); Grundler, D. [Laboratoire des Materiaux Semiconducteurs, EPF Lausanne (Switzerland); Physik-Department E10, Technische Universitaet Muenchen (Germany)

    2013-07-01

    We report on the realization of highly sensitive dc nanoSQUIDs for the investigation of small spin systems in moderate magnetic fields. The Nb SQUIDs are based on normal metal Josephson junctions made of HfTi and patterned by e-beam lithography. We demonstrate stable operation up to B = ± 50 mT without degradation of rms flux noise (S{sub Φ}{sup 1/2} ≤ 280 nΦ{sub 0}/√(Hz)). We also present a multifunctional system combining a Nb nanoSQUID and a low-temperature magnetic force microscope (LTMFM) with a Ni nanotube as a scanning tip. This system allows for magnetization measurements of the Ni tube by using both, LTMFM and SQUID readout. Furthermore, the measurement of magnetic flux Φ vs. position of the particle provides an experimental determination of the coupling factor φ{sub μ} = Φ/μ between SQUID and Ni tube with magnetic moment μ. The results confirm our predictions from numerical simulations, taking into account the SQUID geometry.

  4. System Architecture of Small Unmanned Aerial System for Flight Beyond Visual Line-of-Sight

    Science.gov (United States)

    2015-09-17

    International Conference on Mechatronic and Embedded Systems and Applications (MESA 2011), 28-31 (August 2011) Maddalon Jeffrey M., Kelly J... SYSTEM ARCHITECTURE OF SMALL UNMANNED AERIAL SYSTEM FOR FLIGHT BEYOND VISUAL LINE-OF-SIGHT THESIS...is declared a work of the U.S. Government and is not subject to copyright protection in the United States. AFIT-ENV-MS-15-S-047 SYSTEM

  5. System design study of small lead-bismuth cooled reactor

    International Nuclear Information System (INIS)

    Chikazawa, Yoshitaka; Hori, Toru; Konomura, Mamoru

    2003-07-01

    In phase II of the feasibility study of JNC, we will make a concept of a dispersion power source reactor with various requirements, such as economical competitiveness and safety. In the study of a small lead-bismuth cooled reactor, a concept whose features are long life core, inherent safety, natural convection of cooling system and steam generators in the reactor vessel has been designed since 2000. The investigations which have been done in 2002 are shown as follows; Safety analysis of UTOP considering uncertainty of reactivity. Possibility of reduction of number of control rods. Estimation of construction cost. Transient analyses of UTOP have been done in considering uncertainty of reactivity in order to show the inherent safety in the probabilistic method. And the inherent safety in UTOP is realized under the condition of considering uncertainty. Transient analyses of UTOP with various numbers of control rods have been done and it is suggested that there is possibility of reduction of the number of control rods considering accident managements. The method of cost estimation is a little modified. The cost of reactor vessel is estimated from that of medium sized lead-bismuth cooled reactor and the estimation of a purity control system is by coolant volume flow rate. The construction cost is estimated 850,000yen/kWe. (author)

  6. Evaluation of real-time operating system for small-scale embedded systems

    International Nuclear Information System (INIS)

    Dayang Norhayati Abang Jawawi; Rosbi Mamat

    1999-01-01

    In this paper, the performance of some real-time operating systems for small-scale embedded systems are evaluated based on some criteria. The evaluation is performed qualitatively and quantitatively. The evaluation results based on a case study on an engineering application will be presented. (author)

  7. Analysis of Hybrid-Electric Propulsion System Designs for Small Unmanned Aircraft Systems

    Science.gov (United States)

    2010-03-01

    small EM to provide extra power during acceleration and recharge during deceleration through regenerative braking . Power assist systems are similar...climbing (Fig. 4).18 Like automotive hybrids, the aircraft utilizes a form of regenerative braking by charging its battery pack through propeller...desirable.”5 The inherent risks of all three ISR mission categories lead towards small UAS being the best option in many cases to meet the military’s

  8. Space Solar Power Satellite Systems, Modern Small Satellites, and Space Rectenna

    Science.gov (United States)

    Bergsrud, Corey Alexis Marvin

    Space solar power satellite (SSPS) systems is the concept of placing large satellite into geostationary Earth orbit (GEO) to harvest and convert massive amounts of solar energy into microwave energy, and to transmit the microwaves to a rectifying antenna (rectenna) array on Earth. The rectenna array captures and converts the microwave power into usable power that is injected into the terrestrial electric grid for use. This work approached the microwave power beam as an additional source of power (with solar) for lower orbiting satellites. Assuming the concept of retrodirectivity, a GEO-SSPS antenna array system tracks and delivers microwave power to lower orbiting satellites. The lower orbiting satellites are equipped with a stacked photovoltaic (PV)/rectenna array hybrid power generation unit (HPGU) in order to harvest solar and/or microwave energy for on-board use during orbit. The area, and mass of the PV array part of the HPGU was reduced at about 32% beginning-of-life power in order to achieve the spacecraft power requirements. The HPGU proved to offer a mass decrease in the PGU, and an increase in mission life due to longer living component life of the rectenna array. Moreover, greater mission flexibility is achieved through a track and power delivery concept. To validate the potential advantages offered by a HPGU, a mission concept was presented that utilizes modern small satellites as technology demonstrators. During launch, a smaller power receiving "daughter" satellite sits inside a larger power transmitting "mother" satellite. Once separated from the launch vehicle the daughter satellite is ejected away from the mother satellite, and each satellite deploys its respective power transmitting or power receiving hardware's for experimentation. The concept of close proximity mission operations between the satellites is considered. To validate the technology of the space rectenna array part of the HPGU, six milestones were completed in the design. The first

  9. Small-scale impacts as potential trigger for landslides on small Solar system bodies

    Science.gov (United States)

    Hofmann, Marc; Sierks, Holger; Blum, Jürgen

    2017-07-01

    We conducted a set of experiments to investigate whether millimetre-sized impactors impinging on a granular material at several m s-1 are able to trigger avalanches on small, atmosphereless planetary bodies. These experiments were carried out at the Zentrum für angewandte Raumfahrttechnologie und Mikrogravitation (ZARM) drop tower facility in Bremen, Germany to facilitate a reduced gravity environment. Additional data were gathered at Earth gravity levels in the laboratory. As sample materials we used a ground Howardites, Eucrites and Diogenites (HED) meteorite and the Johnson Space Center (JSC) Mars-1 Martian soil simulant. We found that this type of small-scale impact can trigger avalanches with a moderate probability, if the target material is tilted to an angle close to the angle of repose. We additionally simulated a small-scale impact using the discrete element method code esys-particle. These simulations show that energy transfer from impactor to the target material is most efficient at low- and moderate-impactor inclinations and the transferred energy is retained in particles close to the surface due to a rapid dissipation of energy in lower material layers driven by inelastic collisions. Through Monte Carlo simulations we estimate the time-scale on which small-scale impacts with the observed characteristics will trigger avalanches covering all steep slopes on the surface of a small planetary body to be of the order 105 yr.

  10. Autonomous Spacecraft Communication Interface for Load Planning

    Science.gov (United States)

    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.

  11. Risk of Impaired Control of Spacecraft/Associated Systems and Decreased Mobility Due to Vestibular/Sensorimotor Alterations Associated with Space flight

    Science.gov (United States)

    Bloomberg, Jacob J.; Reschke, Millard F.; Clement, Gilles R.; Mulavara, Ajitkumar P.; Taylor, Laura C..

    2015-01-01

    Control of vehicles and other complex systems is a high-level integrative function of the central nervous system (CNS). It requires well-functioning subsystem performance, including good visual acuity, eye-hand coordination, spatial and geographic orientation perception, and cognitive function. Evidence from space flight research demonstrates that the function of each of these subsystems is altered by removing gravity, a fundamental orientation reference, which is sensed by vestibular, proprioceptive, and haptic receptors and used by the CNS for spatial orientation, posture, navigation, and coordination of movements. The available evidence also shows that the degree of alteration of each subsystem depends on a number of crew- and mission-related factors. There is only limited operational evidence that these alterations cause functional impacts on mission-critical vehicle (or complex system) control capabilities. Furthermore, while much of the operational performance data collected during space flight has not been available for independent analysis, those that have been reviewed are somewhat equivocal owing to uncontrolled (and/or unmeasured) environmental and/or engineering factors. Whether this can be improved by further analysis of previously inaccessible operational data or by development of new operational research protocols remains to be seen. The true operational risks will be estimable only after we have filled the knowledge gaps and when we can accurately assess integrated performance in off-nominal operational settings (Paloski et al. 2008). Thus, our current understanding of the Risk of Impaired Control of Spacecraft/Associated Systems and Decreased Mobility Due to Vestibular/Sensorimotor Alterations Associated with Space flight is limited primarily to extrapolation of scientific research findings, and, since there are limited ground-based analogs of the sensorimotor and vestibular changes associated with space flight, observation of their functional

  12. Robust Parametric Control of Spacecraft Rendezvous

    Directory of Open Access Journals (Sweden)

    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.

  13. Trace Gas Quantification with Small Unmanned Aerial Systems

    Science.gov (United States)

    Schuyler, T. J.; Guzman, M. I.; Bailey, S.; Jacob, J.

    2017-12-01

    Measurements of atmospheric composition are generally performed with advanced instrumentation from ground stations using tall towers and weather balloons or with manned aircraft. Unmanned aerial systems (UAS) are a promising technology for atmospheric monitoring of trace atmospheric gases as they can bridge the gap between the regions of the atmospheric boundary layer measured by ground stations and aircraft. However, in general, the sophisticated instrumentation required for these measurements are heavy, preventing its deployment with small UAS. In order to successfully detect and quantify these gases, sensor packages aboard UAS must be lightweight, have low-power consumption, and possess limits of detection on the ppm scale or below with reasonably fast response times. Thus, a new generation of portable instrument is being developed in this work to meet these requirements employing new sensing packages. The cross sensitivity of these sensors to several gases is examined through laboratory testing of the instrument under variable environmental conditions prior to performing field measurements. Datasets include timestamps with position, temperature, relative humidity, pressure, along with variable mixing ratio values of important greenhouse gases. The work will present an analysis of the results gathered during authorized flights performed during the second CLOUD-MAP§ field campaign held in June 2017. §CLOUD-MAP: Collaboration Leading Operational UAS Development for Meteorology and Atmospheric Physics, a 4-year NSF funded effort.

  14. Spacecraft design project: Low Earth orbit communications satellite

    Science.gov (United States)

    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.

  15. Westinghouse Small Modular Reactor nuclear steam supply system design

    Energy Technology Data Exchange (ETDEWEB)

    Memmott, M. J.; Harkness, A. W.; Van Wyk, J. [Westinghouse Electric Company LLC, 600 Cranberry Woods Drive, Cranberry Twp. PA 16066 (United States)

    2012-07-01

    The Westinghouse Small Modular Reactor (SMR) is an 800 MWt (>225 MWe) integral pressurized water reactor (iPWR), in which all of the components typically associated with the nuclear steam supply system (NSSS) of a nuclear power plant are incorporated within a single reactor pressure vessel. This paper is the first in a series of four papers which describe the design and functionality of the Westinghouse SMR. Also described in this series are the key drivers influencing the design of the Westinghouse SMR and the unique passive safety features of the Westinghouse SMR. Several critical motivators contributed to the development and integration of the Westinghouse SMR design. These design driving motivators dictated the final configuration of the Westinghouse SMR to varying degrees, depending on the specific features under consideration. These design drivers include safety, economics, AP1000{sup R} reactor expertise and experience, research and development requirements, functionality of systems and components, size of the systems and vessels, simplicity of design, and licensing requirements. The Westinghouse SMR NSSS consists of an integral reactor vessel within a compact containment vessel. The core is located in the bottom of the reactor vessel and is composed of 89 modified Westinghouse 17x17 Robust Fuel Assemblies (RFA). These modified fuel assemblies have an active core length of only 2.4 m (8 ft) long, and the entirety of the core is encompassed by a radial reflector. The Westinghouse SMR core operates on a 24 month fuel cycle. The reactor vessel is approximately 24.4 m (80 ft) long and 3.7 m (12 ft) in diameter in order to facilitate standard rail shipping to the site. The reactor vessel houses hot and cold leg channels to facilitate coolant flow, control rod drive mechanisms (CRDM), instrumentation and cabling, an intermediate flange to separate flow and instrumentation and facilitate simpler refueling, a pressurizer, a straight tube, recirculating steam

  16. Dust Interactions on Small Solar System Bodies and Technology Considerations for Exploration

    Science.gov (United States)

    Kobrick, Ryan,; Hoffman, Jeffrey; Pavone, Marco; Street, Kenneth; Rickman, Douglas

    2014-01-01

    Small-bodies such as asteroids and Mars' moons Phobos and Deimos have relatively unknown regolith environments. It is hypothesized that dust preserved in the regolith on the surfaces will have similar mechanical properties to lunar dust because of similar formation processes from micrometeorite bombardment, low relative gravity for slow settling times, and virtually no weathering because there is no atmosphere. This combination of processes infers that small-body dust particles will be highly angular and retain abrasive properties. The focus of this paper uses the mission architecture and engineering design for an asteroid hopper known as Hedgehog, a spherical spacecraft with several symmetric spikes used to aid with tumbling mobility in a low gravity environment. Dust abrasion considerations are highlighted throughout the paper relating to the lead authors' previous work, but act as an example of one of many important dust or regolith physical properties that need to be considered for future exploration. Measurable regolith properties are summarized in order to identify technologies that may be useful for exploration in terms of scientific return and spacecraft design. Previous instruments are summarized in this paper that could be used on the Hedgehog. Opportunities for hardware payloads are highlighted that include low mass solutions or dualpurpose instruments that can measure regolith or dust properties. Finally, dust mitigation suggestions are made for vehicles of this mobility profile.

  17. Spacecraft Attitude Control in Hamiltonian Framework

    DEFF Research Database (Denmark)

    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...

  18. A New Approach to Isolating External Magnetic Field Components in Spacecraft Measurements of the Earth's Magnetic Field Using Global Positioning System observables

    Science.gov (United States)

    Raymond, C.; Hajj, G.

    1994-01-01

    We review the problem of separating components of the magnetic field arising from sources in the Earth's core and lithosphere, from those contributions arising external to the Earth, namely ionospheric and magnetospheric fields, in spacecraft measurements of the Earth's magnetic field.

  19. Precise Relative Positioning of Formation Flying Spacecraft using GPS

    NARCIS (Netherlands)

    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.

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

    Science.gov (United States)

    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.

  1. Developing Collective Training for Small Unmanned Aerial Systems Employment

    Science.gov (United States)

    Durlach, Paula J.; Priest, Heather; Martin, Glenn A.; Saffold, Jay

    2010-01-01

    The projected use of small unmanned aerial systems (SUAS) in military operations will produce training requirements which go beyond current capabilities. The paper describes the development of prototype training procedures and accompanying research simulations to address this need. We initially constructed a testbed to develop simulation-based training for an SUAS operator equipped with a simulated vertical-lift and land SUAS. However, the required training will go beyond merely training an operator how to pilot an SUAS. In addition to tactics, techniques, and procedures for employment of SUASs, collective training methods must be trained. Moreover, the leader of a unit equipped with SUAS will need to learn how to plan missions which incorporate the SUAS, and take into account air space and frequency management considerations. The demands of the task require the leader to allocate personnel to the SUAS mission, communicate and coordinate with those personnel during the mission, and make use of the information provided. To help address these training issues, we expanded our research testbed to include a command and control node (C2 node), to enable communications between a leader and the SUAS operator. In addition, we added a virtual environment in which dismounted infantry missions can be conducted. This virtual environment provides the opportunity for interactions among human-controlled avatars and non-player characters (NPCs), plus authoring tools to construct scenarios. Using these NPCs, a collective exercise involving friendly, enemy, and civilian personnel can be conducted without the need for a human role-player for every entity. We will describe the results of our first experiment, which examined the ability of players to negotiate use of the C2 node and the virtual environment at the same time, in order to see if this is a feasible combination of tools for training development.

  2. The Manned Spacecraft Center and medical technology

    Science.gov (United States)

    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.

  3. Integrated bioenergy conversion concepts for small scale gasification power systems

    Science.gov (United States)

    Aldas, Rizaldo Elauria

    Thermal and biological gasification are promising technologies for addressing the emerging concerns in biomass-based renewable energy, environmental protection and waste management. However, technical barriers such as feedstock quality limitations, tars, and high NOx emissions from biogas fueled engines impact their full utilization and make them suffer at the small scale from the need to purify the raw gas for most downstream processes, including power generation other than direct boiler use. The two separate gasification technologies may be integrated to better address the issues of power generation and waste management and to complement some of each technologies' limitations. This research project investigated the technical feasibility of an integrated thermal and biological gasification concept for parameters critical to appropriately matching an anaerobic digester with a biomass gasifier. Specific studies investigated the thermal gasification characteristics of selected feedstocks in four fixed-bed gasification experiments: (1) updraft gasification of rice hull, (2) indirect-heated gasification of rice hull, (3) updraft gasification of Athel wood, and (4) downdraft gasification of Athel and Eucalyptus woods. The effects of tars and other components of producer gas on anaerobic digestion at mesophilic temperature of 36°C and the biodegradation potentials and soil carbon mineralization of gasification tars during short-term aerobic incubation at 27.5°C were also examined. Experiments brought out the ranges in performance and quality and quantity of gasification products under different operating conditions and showed that within the conditions considered in the study, these gasification products did not adversely impact the overall digester performance. Short-term aerobic incubation demonstrated variable impacts on carbon mineralization depending on tar and soil conditions. Although tars exhibited low biodegradation indices, degradation may be improved if the

  4. Small Footprint Solar/Wind-powered CASTNET System Dataset

    Data.gov (United States)

    U.S. Environmental Protection Agency — In this Research Effort “Small Footprint Solar/Wind-Powered CASTNET System” there are two data sets. One data set contains atmospheric concentration measurements, at...

  5. Metrical theorems on systems of small inhomogeneous linear forms

    DEFF Research Database (Denmark)

    Hussain, Mumtaz; Kristensen, Simon

    In this paper we establish complete Khintchine-Groshev and Schmidt type theorems for inhomogeneous small linear forms in the so-called doubly metric case, in which the inhomogeneous parameter is not fixed.......In this paper we establish complete Khintchine-Groshev and Schmidt type theorems for inhomogeneous small linear forms in the so-called doubly metric case, in which the inhomogeneous parameter is not fixed....

  6. Metrical results on systems of small linear forms

    DEFF Research Database (Denmark)

    Hussain, M.; Kristensen, Simon

    In this paper the metric theory of Diophantine approximation associated with the small linear forms is investigated. Khintchine--Groshev theorems are established along with Hausdorff measure generalization without the monotonic assumption on the approximating function.......In this paper the metric theory of Diophantine approximation associated with the small linear forms is investigated. Khintchine--Groshev theorems are established along with Hausdorff measure generalization without the monotonic assumption on the approximating function....

  7. Astronaut L. Gordon Cooper is assisted into his spacecraft for tests

    Science.gov (United States)

    1963-01-01

    NASA and McDonnell Aircraft Corp. spacecraft technicians assist Astronaut L. Gordon Cooper into his spacecraft prior to undergoing tests in the altitude chamber. These tests are used to determine the operating characteristcs of the overall environmental control system.

  8. Operational Philosophy Concerning Manned Spacecraft Cabin Leaks

    Science.gov (United States)

    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

  9. Improved techniques for predicting spacecraft power

    International Nuclear Information System (INIS)

    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

  10. FORTE spacecraft vibration mitigation. Final report

    International Nuclear Information System (INIS)

    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

  11. 30-kW SEP Spacecraft as Secondary Payloads for Low-Cost Deep Space Science Missions

    Science.gov (United States)

    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

  12. Integration of a Fire Detector into a Spacecraft

    Science.gov (United States)

    Linford, R. M. F.

    1972-01-01

    A detector sensitive to only the ultraviolet radiation emitted by flames has been selected as the basic element of the NASA Skylab fire detection system. It is sensitive to approximately 10(exp -12)W of radiation and will detect small flames at distances in excess of 3m. The performance of the detector was verified by experiments in an aircraft flying zero-gravity parabolas to simulate the characteristics of a fire which the detector must sense. Extensive investigation and exacting design was necessary to exclude all possible sources of false alarms. Optical measurements were made on all the spacecraft windows to determine the amount of solar radiation transmitted. The lighting systems and the onboard experiments also were appraised for ultraviolet emissions. Proton-accelerator tests were performed to determine the interaction of the Earth's trapped radiation belts with the detectors and the design of the instrument was modified to negate these effects.

  13. MIDN: A spacecraft Micro-dosimeter mission

    International Nuclear Information System (INIS)

    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)

  14. About the Big Graphs Arising when Forming the Diagnostic Models in a Reconfigurable Computing Field of Functional Monitoring and Diagnostics System of the Spacecraft Onboard Control Complex

    Directory of Open Access Journals (Sweden)

    L. V. Savkin

    2015-01-01

    Full Text Available One of the problems in implementation of the multipurpose complete systems based on the reconfigurable computing fields (RCF is the problem of optimum redistribution of logicalarithmetic resources in growing scope of functional tasks. Irrespective of complexity, all of them are transformed into an orgraph, which functional and topological structure is appropriately imposed on the RCF based, as a rule, on the field programmable gate array (FPGA.Due to limitation of the hardware configurations and functions realized by means of the switched logical blocks (SLB, the abovementioned problem becomes even more critical when there is a need, within the strictly allocated RCF fragment, to realize even more complex challenge in comparison with the problem which was solved during the previous computing step. In such cases it is possible to speak about graphs of big dimensions with respect to allocated RCF fragment.The article considers this problem through development of diagnostic algorithms to implement diagnostics and control of an onboard control complex of the spacecraft using RCF. It gives examples of big graphs arising with respect to allocated RCF fragment when forming the hardware levels of a diagnostic model, which, in this case, is any hardware-based algorithm of diagnostics in RCF.The article reviews examples of arising big graphs when forming the complicated diagnostic models due to drastic difference in formation of hardware levels on closely located RCF fragments. It also pays attention to big graphs emerging when the multichannel diagnostic models are formed.Three main ways to solve the problem of big graphs with respect to allocated RCF fragment are given. These are: splitting the graph into fragments, use of pop-up windows with relocating and memorizing intermediate values of functions of high hardware levels of diagnostic models, and deep adaptive update of diagnostic model.It is shown that the last of three ways is the most efficient

  15. THE FUTURE OF SPACECRAFT NUCLEAR PROPULSION

    OpenAIRE

    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.

  16. Smoothing identification of systems with small non-linearities

    Czech Academy of Sciences Publication Activity Database

    Kozánek, Jan; Piranda, J.

    2003-01-01

    Roč. 38, č. 1 (2003), s. 71-84 ISSN 0025-6455 R&D Projects: GA ČR GA101/00/1471 Institutional research plan: CEZ:AV0Z2076919 Keywords : identification * small non-linearities * smoothing methods Subject RIV: BI - Acoustics Impact factor: 0.237, year: 2003

  17. Investigation of Practical Flight Envelope Protection Systems for Small Aircraft

    NARCIS (Netherlands)

    Falkena, W.; Borst, C.; Mulder, J.A.

    2010-01-01

    Personal air transportation utilizing small aircraft is a market that is expected to grow significantly in the future. For this segment, “stick and rudder” related accidents should be mitigated to guide this process in a safe manner. Instead of downscaling advanced and expensive fly-by-wire

  18. An Accounting System for Solid Waste Management in Small Communities.

    Science.gov (United States)

    Zausner, Eric R.

    This pamphlet provides a guide to the type and quantity of information to be collected for effective solid waste management in small communities. It is directed at municipal or private personnel involved in the operation and ownership of management facilities. Sample activity reports are included for reference. (CS)

  19. Investigation of Practical Flight Control Systems for Small Aircraft

    NARCIS (Netherlands)

    Falkena, W.

    2012-01-01

    Personal air transportation utilizing small aircraft is a market that is expected to grow significantly in the near future. However, seventy times more accidents occur in this segment as compared with the commercial aviation sector. The majority of these accidents is related to handling and control

  20. Integrated Strip Foundation Systems for Small Residential Buildings

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    2010-01-01

    A prefabricated lightweight element was designed for a strip foundation that was used on site as the bases of two small residential buildings, in this case single-family houses; one was built with a double-brick exterior wall separated by mineral fiber insulation and the other was built with a wood...

  1. Accounting Systems in Small and Micro Enterprises in Kenya ...

    African Journals Online (AJOL)

    For a long time in Kenya, the practices and principles of accounting have been viewed to be for use by corporate and other formally structured organizations. This paper seeks to investigate what accounting means to small and micro traders in Kenya, by reviewing the practices and principles they use in running their ...

  2. Publishing Systems Same for J-Schools and Small Papers.

    Science.gov (United States)

    Oates, William R.

    1987-01-01

    Discusses how professional publishing software allows journalism education programs to accurately create the publishing environment students will encounter at small and medium-sized newspapers. Claims that the laser jet printer is the key ingredient that is turning the personal computer revolution into a newspaper publishing revolution, describing…

  3. NASA's Electronic Procurement System and the Impact on Small Business

    Science.gov (United States)

    Dozier, Ken

    1998-01-01

    Three workshops, held in Lancaster, Orange County and Compton, were produced by the Los Angeles Regional Technology Alliance (LARTA) and NASA Far West Technology Transfer Center (FWRTTC). The workshops were held on December 12, 1997, February 5, 1998, and March 30, 1998, respectively. The purpose behind these workshops was to spread information regarding NASA procurement opportunities to small businesses in the region. This was accomplished by inviting economic and business development organizations to the three workshops, presenting NASA procurement resources to them, and asking them to distribute this information to the small businesses in their communities. With the assistance of LARTA, marketing and publicity in the form of direct mail, telemarketing, and promotion via a web site was implemented to publicize the workshops. These methods were remarkably effective because they enabled the workshops to attain its full capacity. Further publicity was provided by Wendy Reed of Valley Focus Magazine, an Antelope Valley Magazine aimed at business people. Her article entitled, "Doing Business with the Government" recapped the Lancaster workshop that she had attended and made references to several presentations. In the article, she discussed selling to the government via electronic commerce, and specifically mentioned Robert Medina, the NASA Dryden Small Business Specialist, as a contact person for those interested in pursuing procurement opportunities. The feedback provided by the participants is illustrated by the enclosed graphs and charts. These figures represent the number of participants who have frequented web sites presented at workshops, specifically the NASA procurement resources, and how extensive information dissemination was. Input from participants was favorable and encouraged more NASA Dryden workshops directly to the small business communities. There was an overwhelming response to the benefit of the NASA procurement opportunities presented at the

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

    Science.gov (United States)

    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.

  5. On-orbit supervisor for controlling spacecraft

    Science.gov (United States)

    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.

  6. TTEthernet for Integrated Spacecraft Networks

    Science.gov (United States)

    Loveless, Andrew

    2015-01-01

    Aerospace projects have traditionally employed federated avionics architectures, in which each computer system is designed to perform one specific function (e.g. navigation). There are obvious downsides to this approach, including excessive weight (from so much computing hardware), and inefficient processor utilization (since modern processors are capable of performing multiple tasks). There has therefore been a push for integrated modular avionics (IMA), in which common computing platforms can be leveraged for different purposes. This consolidation of multiple vehicle functions to shared computing platforms can significantly reduce spacecraft cost, weight, and design complexity. However, the application of IMA principles introduces significant challenges, as the data network must accommodate traffic of mixed criticality and performance levels - potentially all related to the same shared computer hardware. Because individual network technologies are rarely so competent, the development of truly integrated network architectures often proves unreasonable. Several different types of networks are utilized - each suited to support a specific vehicle function. Critical functions are typically driven by precise timing loops, requiring networks with strict guarantees regarding message latency (i.e. determinism) and fault-tolerance. Alternatively, non-critical systems generally employ data networks prioritizing flexibility and high performance over reliable operation. Switched Ethernet has seen widespread success filling this role in terrestrial applications. Its high speed, flexibility, and the availability of inexpensive commercial off-the-shelf (COTS) components make it desirable for inclusion in spacecraft platforms. Basic Ethernet configurations have been incorporated into several preexisting aerospace projects, including both the Space Shuttle and International Space Station (ISS). However, classical switched Ethernet cannot provide the high level of network

  7. Photovoltaic power supply for appliances and small systems. Final report; Photovoltaik fuer Geraete und Kleinsysteme. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Roth, W.; Anton, L.; Benz, J.; Kaiser, R.; Kuhmann, J.; Puls, H.G.; Pfanner, N.; Schmidt, H.; Schulz, W.; Steinhueser, A.

    2002-06-01

    The economic prospects of PV power supply to appliances and small systems were investigated. The research project was aimed at improving the conditions for efficient development of appliances and small systems with photovoltaic power supply and autonomous systems not connected to the grid. Innovative products were developed and tested in cooperation with industrial organizations. The project is to help small and medium-sized organizations with a technological orientation and enhance technology transfer between science and industry.

  8. Conceptual design of small-sized HTGR system (1). Major specifications and system designs

    International Nuclear Information System (INIS)

    Ohashi, Hirofumi; Sato, Hiroyuki; Tazawa, Yujiro; Yan, Xing L.; Tachibana, Yukio

    2011-06-01

    Japan Atomic Energy Agency (JAEA) has started a conceptual design of a 50MWt small-sized high temperature gas cooled reactor (HTGR) for steam supply and electricity generation (HTR50S), which is a first-of-kind of the commercial plant or a demonstration plant of a small-sized HTGR system for steam supply to the industries and district heating and electricity generation by a steam turbine, to deploy in developing countries in the 2030s. The design philosophy is that the HTR50S is a high advanced reactor, which is reducing the R and D risk based on the HTTR design, upgrading the performance and reducing the cost for commercialization by utilizing the knowledge obtained by the HTTR operation and the GTHTR300 design. The major specifications of the HTR50S were determined and targets of the technology demonstration using the HTR50S (e.g., the increasing the power density, reduction of the number of uranium enrichment in the fuel, increasing the burn up, side-by-side arrangement between the reactor pressure vessel and the steam generator) were identified. In addition, the system design of HTR50S, which offers the capability of electricity generation, cogeneration of electricity and steam for a district heating and industries, was performed. Furthermore, a market size of small-sized HTGR systems was investigated. (author)

  9. Buying Program of the Standard Automated Materiel Management System. Automated Small Purchase System: Defense Supply Center Philadelphia

    National Research Council Canada - National Science Library

    2001-01-01

    The Standard Automated Materiel Management System Automated Small Purchase System is a fully automated micro-purchases system used by the General and Industrial Directorate at the Defense Supply Center Philadelphia...

  10. Small leak damage and protection systems in steam generators

    International Nuclear Information System (INIS)

    Greene, D.A.

    1976-01-01

    A small leak of water into sodium in a liquid metal heated steam generator can cause damage to adjacent tubes, a phenomenon termed wastage. Theories on this phenomenon range from corrosion from sodium water reaction products to erosion by supersonic particles. An alternative approach considers the water injection to form a simple combustion process. Using this approach many aspects of over 250 wastage experiments can be explained both analytically and physically. The U.S. has an extensive technology in the general area of acoustic surveillance. High temperature in-sodium microphones, in-vessel waveguides, and data analysis techniques have been successfully demonstrated in national development programs. This technology has been applied specifically to the development of an acoustic leak detection/location monitor for small leaks in an operating steam generator

  11. Novel Musculoskeletal Loading System for Small Exercise Devices

    Science.gov (United States)

    Downs, Meghan; Newby, Nate; Trinh, Tinh; Hanson, Andrea

    2016-01-01

    Long duration spaceflight places astronauts at increased risk for muscle strain and bone fracture upon return to a 1-g or partial gravity environment. Functionally limiting decrements in musculoskeletal health are likely during Mars proving-ground and Earth-independent missions given extended transit times and the vehicle limitations for exercise devices (low-mass, small volume, little to no power). This is particularly alarming for exploration missions because astronauts will be required to perform novel and physically demanding tasks (i.e. vehicle egress, exploration, and habitat building activities) on unfamiliar terrain. Accordingly, NASA's exploration roadmap identifies the need for development of small exercise equipment that can prevent musculoskeletal atrophy and has the ability to assess musculoskeletal health at multiple time points during long-duration missions.

  12. Note: Development of a small maglev-type antirolling system.

    Science.gov (United States)

    Park, Cheol Hoon; Park, Hee Chang; Cho, Han Wook; Moon, Seok Jun; Chung, Tae Young

    2010-05-01

    Various passive and/or active antirolling devices have been used for suppressing the rolling motion of ships in the ocean. In this study, a maglev-type active mass driver (AMD) is developed for controlling the rolling motion of a shiplike structure. No friction is generated during the motion of this maglev-type AMD, as the moving mass is floated by the magnetic levitation force and displaced by the propulsion force generated by the linear motor. For verifying the feasibility of the proposed method, a small AMD having a moving mass of approximately 4.0 kg is constructed and used in a small-scale model of a catamaran. This paper presents the detailed design procedures and obtained experimental results. Our results show that the developed maglev-type AMD has the potential for use in controlling the rolling motion of ships and other oceanographic vessels.

  13. Hyperpolarized singlet NMR on a small animal imaging system

    DEFF Research Database (Denmark)

    Laustsen, Christoffer; Pileio, Giuseppe; Tayler, Michael C. D.

    2012-01-01

    Nuclear spin hyperpolarization makes a significant advance toward overcoming the sensitivity limitations of in vivo magnetic resonance imaging, particularly in the case of low-gamma nuclei. The sensitivity may be improved further by storing the hyperpolarization in slowly relaxing singlet...... populations of spin- 1/2 pairs. Here, we report hyperpolarized 13C spin order transferred into and retrieved from singlet spin order using a small animal magnetic resonance imaging scanner. For spins in sites with very similar chemical shifts, singlet spin order is sustained in high magnetic field without...... requiring strong radiofrequency irradiation. The demonstration of robust singlet-to-magnetization conversion, and vice versa, on a small animal scanner, is promising for future in vivo and clinical deployments....

  14. The SNR-300 steam generator small leak detection system

    International Nuclear Information System (INIS)

    Dumm, K.

    1984-01-01

    Small leak detection in the SNR-300 steam generator moduls is achieved by hydrogen meters. Development and design of the Nickel membrane - ion getter pump combination are described and sensitivity requests derived. Results of calibration tests by water/steam injections in a sodium loop are presented. The arrangement and interconnection of signals in SNR-300 are given and possibilities for inservice calibrations are discussed, supported by long time operation tests in the KNK-reactor plant. (author)

  15. Small business innovation research. Abstracts of 1988 phase 1 awards

    Science.gov (United States)

    1990-01-01

    Non-proprietary proposal abstracts of Phase 1 Small Business Innovation Research (SBIR) projects supported by NASA are presented. Projects in the fields of aeronautical propulsion, aerodynamics, acoustics, aircraft systems, materials and structures, teleoperators and robots, computer sciences, information systems, data processing, spacecraft propulsion, bioastronautics, satellite communication, and space processing are covered.

  16. Training and Technical Assistance for Small Systems Funding

    Science.gov (United States)

    Provides water and wastewater system staff and private well owners with training and tools to enhance system operations and management practices, and support EPA’s continuing efforts to protect public health and promote sustainability.

  17. Applications concepts of small regenerative cryocoolers in superconducitng magnet systems

    NARCIS (Netherlands)

    van der Laan, M.T.G.; van der Laan, M.T.G.; Tax, R.B.; ten Kate, Herman H.J.

    1992-01-01

    Superconducting magnets are in growing use outside laboratories for example MRI scanners in hospitals. Other applications under development are magnet systems for separation, levitated trains and ship propulsion. The application of cryocoolers can make these systems more practical. Interfacing these

  18. District heating systems for small scale development areas

    Energy Technology Data Exchange (ETDEWEB)

    McDougall, Rory e-mail: rory.mcdougall@online.no; Jensen, Bjoernulf

    2008-09-15

    Building projects are normally developed without considering integrated heating systems, especially where properties are for further sale. Due to focus on energy efficiency and environmental impact it is worth considering district heating systems, which include several energy carriers. The choice of energy carrier is assessed to optimize energy costs, account for environmental impact and obtain reliable heating supply, thus giving an energy flexible system for several buildings as opposed to individual heating systems in each building

  19. Spacecraft Charging and the Microwave Anisotropy Probe Spacecraft

    Science.gov (United States)

    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.

  20. Investigation of Phase Transition-Based Tethered Systems for Small Body Sample Capture

    Science.gov (United States)

    Quadrelli, Marco; Backes, Paul; Wilkie, Keats; Giersch, Lou; Quijano, Ubaldo; Scharf, Daniel; Mukherjee, Rudranarayan

    2009-01-01

    This paper summarizes the modeling, simulation, and testing work related to the development of technology to investigate the potential that shape memory actuation has to provide mechanically simple and affordable solutions for delivering assets to a surface and for sample capture and possible return to Earth. We investigate the structural dynamics and controllability aspects of an adaptive beam carrying an end-effector which, by changing equilibrium phases is able to actively decouple the end-effector dynamics from the spacecraft dynamics during the surface contact phase. Asset delivery and sample capture and return are at the heart of several emerging potential missions to small bodies, such as asteroids and comets, and to the surface of large bodies, such as Titan.

  1. Modeling and Testing of Phase Transition-Based Deployable Systems for Small Body Sample Capture

    Science.gov (United States)

    Quadrelli, Marco; Backes, Paul; Wilkie, Keats; Giersch, Lou; Quijano, Ubaldo; Keim, Jason; Mukherjee, Rudranarayan

    2009-01-01

    This paper summarizes the modeling, simulation, and testing work related to the development of technology to investigate the potential that shape memory actuation has to provide mechanically simple and affordable solutions for delivering assets to a surface and for sample capture and return. We investigate the structural dynamics and controllability aspects of an adaptive beam carrying an end-effector which, by changing equilibrium phases is able to actively decouple the end-effector dynamics from the spacecraft dynamics during the surface contact phase. Asset delivery and sample capture and return are at the heart of several emerging potential missions to small bodies, such as asteroids and comets, and to the surface of large bodies, such as Titan.

  2. Small-Scale Pellet Heating Systems from Consumer Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Mahapatra, K; Gustavsson, L [Mid Sweden Univ., Oestersund (Sweden). Ecotechnology

    2006-07-15

    A questionnaire survey of 1,500 detached house owners was carried out in the autumn of 2004 to find out the factors influencing the adoption and diffusion of pellet heating systems in the Swedish residential sector. The results revealed that most of the respondents had no plans to install new heating systems as they were satisfied with their existing ones. Economic aspects and functional reliability were the most important factors in the respondents' choice of heating system while environmental factors were of less importance. Therefore, internalizing external costs, such as environmental costs, might be effective in influencing house owners to adopt environmentally benign heating systems. Installers were the most important source of information on heating systems. Hence, it is important that they could inform the consumers comprehensively and accurately about different heating systems. Respondents perceived the relative advantage of pellet boilers over oil or electricity-based heating systems, but bedrock heat pump system was ranked higher than pellet heating system in every aspect except for investment cost. Pellet heating system has advantage over district heating system with respect to investment cost and annual cost of heating. District heating system was considered as most functionally reliable and automatic.

  3. Small-Scale Pellet Heating Systems from Consumer Perspective

    International Nuclear Information System (INIS)

    Mahapatra, K.; Gustavsson, L.

    2006-01-01

    A questionnaire survey of 1,500 detached house owners was carried out in the autumn of 2004 to find out the factors influencing the adoption and diffusion of pellet heating systems in the Swedish residential sector. The results revealed that most of the respondents had no plans to install new heating systems as they were satisfied with their existing ones. Economic aspects and functional reliability were the most important factors in the respondents' choice of heating system while environmental factors were of less importance. Therefore, internalizing external costs, such as environmental costs, might be effective in influencing house owners to adopt environmentally benign heating systems. Installers were the most important source of information on heating systems. Hence, it is important that they could inform the consumers comprehensively and accurately about different heating systems. Respondents perceived the relative advantage of pellet boilers over oil or electricity-based heating systems, but bedrock heat pump system was ranked higher than pellet heating system in every aspect except for investment cost. Pellet heating system has advantage over district heating system with respect to investment cost and annual cost of heating. District heating system was considered as most functionally reliable and automatic

  4. [Track and trigger systems in Denmark - small country, great variations].

    Science.gov (United States)

    Lønnee, Mads; Bukan, Ramin Brandt; Waldau, Tina; Møller, Ann Merete; Bukan, Katrine Brandt

    2018-05-07

    A track and trigger (TAT) system and mobile emergency team (MET) can aid observation and care for admitted patients in the hospital ward. We have examined the literature and find evidence, though not strong, that the introduction of TAT and MET systems reduce hospital mortality. However, in Denmark, many different TAT systems are used, and several hospitals do not have MET. We believe, that a standardised national TAT system could encourage interregional research and the investigation of system compliance, cost-benefit and impact on intensive care unit admissions.

  5. High-spatial-resolution electron density measurement by Langmuir probe for multi-point observations using tiny spacecraft

    Science.gov (United States)

    Hoang, H.; Røed, K.; Bekkeng, T. A.; Trondsen, E.; Clausen, L. B. N.; Miloch, W. J.; Moen, J. I.

    2017-11-01

    A method for evaluating electron density using a single fixed-bias Langmuir probe is presented. The technique allows for high-spatio-temporal resolution electron density measurements, which can be effectively carried out by tiny spacecraft for multi-point observations in the ionosphere. The results are compared with the multi-needle Langmuir probe system, which is a scientific instrument developed at the University of Oslo comprising four fixed-bias cylindrical probes that allow small-scale plasma density structures to be characterized in the ionosphere. The technique proposed in this paper can comply with the requirements of future small-sized spacecraft, where the cost-effectiveness, limited space available on the craft, low power consumption and capacity for data-links need to be addressed. The first experimental results in both the plasma laboratory and space confirm the efficiency of the new approach. Moreover, detailed analyses on two challenging issues when deploying the DC Langmuir probe on a tiny spacecraft, which are the limited conductive area of the spacecraft and probe surface contamination, are presented in the paper. It is demonstrated that the limited conductive area, depending on applications, can either be of no concern for the experiment or can be resolved by mitigation methods. Surface contamination has a small impact on the performance of the developed probe.

  6. Oscillation matrices and kernels and small vibrations of mechanical systems

    CERN Document Server

    Gantmacher, F R

    2002-01-01

    Fifty years after the original Russian Edition, this classic work is finally available in English for the general mathematical audience. This book lays the foundation of what later became "Krein's Theory of String". The original ideas stemming from mechanical considerations are developed with exceptional clarity. A unique feature is that it can be read profitably by both research mathematicians and engineers. The authors study in depth small oscillations of one-dimensional continua with a finite or infinite number of degrees of freedom. They single out an algebraic property responsible for the

  7. Spacecraft early design validation using formal methods

    International Nuclear Information System (INIS)

    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)

  8. Determination of Realistic Fire Scenarios in Spacecraft

    Science.gov (United States)

    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.

  9. Passive Devices for Advanced Fluid Management aboard Spacecraft, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Acute challenges are faced by the designers of fluid systems for spacecraft because of the persistently unfamiliar and unforgiving low-g environment. For example,...

  10. Distributed Control Architectures for Precision Spacecraft Formations, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — LaunchPoint Technologies, Inc. (LaunchPoint) proposes to develop synthesis methods and design architectures for distributed control systems in precision spacecraft...

  11. A Quantized State Approach to On-line Simulation for Spacecraft Autonomy

    DEFF Research Database (Denmark)

    Alminde, Lars; Stoustrup, Jakob; Bendtsen, Jan Dimon

    2006-01-01

    Future space applications will require an increased level of operational autonomy. This calls for declarative methods for spacecraft state estimation and control, so that the spacecraft engineer can focus on modeling the spacecraft rather than implementing all details of the on-line system. Celeb...

  12. Radiation production and absorption in human spacecraft shielding systems under high charge and energy Galactic Cosmic Rays: Material medium, shielding depth, and byproduct aspects

    Science.gov (United States)

    Barthel, Joseph; Sarigul-Klijn, Nesrin

    2018-03-01

    Deep space missions such as the planned 2025 mission to asteroids require spacecraft shields to protect electronics and humans from adverse effects caused by the space radiation environment, primarily Galactic Cosmic Rays. This paper first reviews the theory on how these rays of charged particles interact with matter, and then presents a simulation for a 500 day Mars flyby mission using a deterministic based computer code. High density polyethylene and aluminum shielding materials at a solar minimum are considered. Plots of effective dose with varying shield depth, charged particle flux, and dose in silicon and human tissue behind shielding are presented.

  13. An air bearing system for small high speed gas turbines

    Science.gov (United States)

    Turner, A. B.; Davies, S. J.; Nimir, Y. L.

    1994-03-01

    This paper describes the second phase of an experimental program concerning the application of air bearings to small turbomachinery test rigs and small gas turbines. The first phase examined externally pressurized (EP) journal bearings, with a novel EP thrust bearing, for application to 'warm air' test rigs, and was entirely successful at rotational speeds in excess of 100,000 rpm. This second phase examined several designs of tilting pad-spiring journal bearings, one with a novel form of externally pressurized pad, but all using the original EP thrust bearing. The designs tested are described, including some oscillogram traces, for tests up to a maximum of 70,000 rpm; the most successful using a carbon pad-titanium beam spring arrangement. The thrust bearing which gave trouble-free operation throughout, is also described. The results of an original experiment to measure the 'runway speed' of a radial inflow turbine are also presented, which show that overspeeds of 58 percent above the design speed can result from free-power turbine coupling failure.

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

    Science.gov (United States)

    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.

  15. The development of a control system for a small high speed steam microturbine generator system

    Science.gov (United States)

    Alford, A.; Nichol, P.; Saunders, M.; Frisby, B.

    2015-08-01

    Steam is a widely used energy source. In many situations steam is generated at high pressures and then reduced in pressure through control valves before reaching point of use. An opportunity was identified to convert some of the energy at the point of pressure reduction into electricity. To take advantage of a market identified for small scale systems, a microturbine generator was designed based on a small high speed turbo machine. This machine was packaged with the necessary control valves and systems to allow connection of the machine to the grid. Traditional machines vary the speed of the generator to match the grid frequency. This was not possible due to the high speed of this machine. The characteristics of the rotating unit had to be understood to allow a control that allowed export of energy at the right frequency to the grid under the widest possible range of steam conditions. A further goal of the control system was to maximise the efficiency of generation under all conditions. A further complication was to provide adequate protection for the rotating unit in the event of the loss of connection to the grid. The system to meet these challenges is outlined with the solutions employed and tested for this application.

  16. Island operation - modelling of a small hydro power system

    Energy Technology Data Exchange (ETDEWEB)

    Skarp, Stefan

    2000-02-01

    Simulation is a useful tool for investigating a system behaviour. It is a way to examine operating situations without having to perform them in reality. If someone for example wants to test an operating situation where the system possibly will demolish, a computer simulation could be a both cheaper and safer way than to do the test in reality. This master thesis performs and analyses a simulation, modelling an electronic power system. The system consists of a minor hydro power station, a wood refining industry, and interconnecting power system components. In the simulation situation the system works in a so called island operation. The thesis aims at making a capacity analysis of the current system. Above all, the goal is to find restrictions in load power profile of the consumer, under given circumstances. The computer software used in simulations is Matlab and its additional program PSB (Power System Blockset). The work has been carried out in co-operation with the power supplier Skellefteaa Kraft, where the problem formulation of this master thesis was founded.

  17. Laser system for measuring small changes in plasma tracer concentrations.

    Science.gov (United States)

    Klaesner, J W; Pou, N A; Parker, R E; Galloway, R L; Roselli, R J

    1996-01-01

    The authors developed a laser-diode system that can be used for on-line optical concentration measurements in physiologic systems. Previous optical systems applied to whole blood have been hampered by artifacts introduced by red blood cells (RBCs). The system introduced here uses a commercially available filter cartridge to separate RBCs from plasma before plasma concentration measurements are made at a single wavelength. The filtering characteristics of the Cellco filter cartridge (#4007-10, German-town, MD) were adequate for use in the on-line measurement system. The response time of the filter cartridge was less than 40 seconds, and the sieving characteristics of the filter for macromolecules were excellent, with filtrate-to-plasma albumin ratios of 0.98 +/- 0.11 for studies in sheep and 0.94 +/- 0.15 for studies in dogs. The 635-nm laser diode system developed was shown to be more sensitive than the spectrophotometer used in previous studies (Klaesner et al., Annals of Biomedical Engineering, 1994; 22, 660-73). The new system was used to measure the product of filtration coefficient (Kfc) and reflection coefficient for albumin (delta f) in an isolated canine lung preparation. The delta fKfc values [mL/(cmH2O.min.100 g dry lung weight)] measured with the laser diode system (0.33 +/- 0.22) compared favorably with the delta fKfc obtained using a spectrophotometer (0.27 +/- 0.20) and with the Kfc obtained using the blood-corrected gravimetric method (0.32 +/- 0.23). Thus, this new optical system was shown to accurately measure plasma concentration changes in whole blood for physiologic levels of Kfc. The same system can be used with different optical tracers and different source wavelengths to make optical plasma concentration measurements for other physiologic applications.

  18. Schema for Spacecraft-Command Dictionary

    Science.gov (United States)

    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.

  19. Small photovoltaic setup for the air conditioning system

    Science.gov (United States)

    Masiukiewicz, Maciej

    2017-10-01

    The increasing interest in air conditioning systems for residential applications in Poland will certainly increase the demand for electricity during the summer period. Due to this fact a growing interest in solutions that help to lower the electricity consumption in this sector is observed. The problem of increased energy demand for air conditioning purposes can be solved by transfer the consumption of electricity from the grid system to renewable energy sources (RES). The greatest demand for cooling occurs during the biggest sunlight. This is the basis for the analysis of technical power system based on photovoltaic cells (PV) to power the split type air conditioner. The object of the study was the commercial residential airconditioning inverter units with a capacity of 2.5kW. A network electricity production system for their own use with the possibility of buffering energy in batteries (OFF-GRID system). Currently, on the Polish market, there are no developed complete solutions dedicated to air conditioning systems based on PV. In Poland, solar energy is mainly used for heat production in solar collectors. The proposed solution will help to increase the popularity of PV systems in the Polish market as an alternative to other RES. The basic conclusion is that the amount of PV energy generated was sufficient to cover the daily energy requirement of the air conditioner.

  20. Small photovoltaic setup for the air conditioning system

    Directory of Open Access Journals (Sweden)

    Masiukiewicz Maciej

    2017-01-01

    Full Text Available The increasing interest in air conditioning systems for residential applications in Poland will certainly increase the demand for electricity during the summer period. Due to this fact a growing interest in solutions that help to lower the electricity consumption in this sector is observed. The problem of increased energy demand for air conditioning purposes can be solved by transfer the consumption of electricity from the grid system to renewable energy sources (RES. The greatest demand for cooling occurs during the biggest sunlight. This is the basis for the analysis of technical power system based on photovoltaic cells (PV to power the split type air conditioner. The object of the study was the commercial residential airconditioning inverter units with a capacity of 2.5kW. A network electricity production system for their own use with the possibility of buffering energy in batteries (OFF-GRID system. Currently, on the Polish market, there are no developed complete solutions dedicated to air conditioning systems based on PV. In Poland, solar energy is mainly used for heat production in solar collectors. The proposed solution will help to increase the popularity of PV systems in the Polish market as an alternative to other RES. The basic conclusion is that the amount of PV energy generated was sufficient to cover the daily energy requirement of the air conditioner.