WorldWideScience

Sample records for space debris symposium

  1. Space Debris & its Mitigation

    Science.gov (United States)

    Kaushal, Sourabh; Arora, Nishant

    2012-07-01

    Space debris has become a growing concern in recent years, since collisions at orbital velocities can be highly damaging to functioning satellites and can also produce even more space debris in the process. Some spacecraft, like the International Space Station, are now armored to deal with this hazard but armor and mitigation measures can be prohibitively costly when trying to protect satellites or human spaceflight vehicles like the shuttle. This paper describes the current orbital debris environment, outline its main sources, and identify mitigation measures to reduce orbital debris growth by controlling these sources. We studied the literature on the topic Space Debris. We have proposed some methods to solve this problem of space debris. We have also highlighted the shortcomings of already proposed methods by space experts and we have proposed some modification in those methods. Some of them can be very effective in the process of mitigation of space debris, but some of them need some modification. Recently proposed methods by space experts are maneuver, shielding of space elevator with the foil, vaporizing or redirecting of space debris back to earth with the help of laser, use of aerogel as a protective layer, construction of large junkyards around international space station, use of electrodynamics tether & the latest method proposed is the use of nano satellites in the clearing of the space debris. Limitations of the already proposed methods are as follows: - Maneuvering can't be the final solution to our problem as it is the act of self-defence. - Shielding can't be done on the parts like solar panels and optical devices. - Vaporizing or redirecting of space debris can affect the human life on earth if it is not done in proper manner. - Aerogel has a threshold limit up to which it can bear (resist) the impact of collision. - Large junkyards can be effective only for large sized debris. In this paper we propose: A. The Use of Nano Tubes by creating a mesh

  2. Space Debris Mitigation Guidelines

    Science.gov (United States)

    Johnson, Nicholas L.

    2011-01-01

    The purpose of national and international space debris mitigation guides is to promote the preservation of near-Earth space for applications and exploration missions far into the future. To accomplish this objective, the accumulation of objects, particularly in long-lived orbits, must be eliminated or curtailed.

  3. Space 2000 Symposium

    Science.gov (United States)

    1999-01-01

    The purpose of the Space 2000 Symposium is to present the creativity and achievements of key figures of the 20th century. It offers a retrospective discussion on space exploration. It considers the future of the enterprise, and the legacy that will be left for future generations. The symposium includes panel discussions, smaller session meetings with some panelists, exhibits, and displays. The first session entitled "From Science Fiction to Science Facts" commences after a brief overview of the symposium. The panel discussions include talks on space exploration over many decades, and the missions of the millennium to search for life on Mars. The second session, "Risks and Rewards of Human Space Exploration," focuses on the training and health risks that astronauts face on their exploratory mission to space. Session three, "Messages and Messengers Informing and Inspire Space Exploration and the Public," focuses on the use of TV medium by educators and actors to inform and inspire a wide variety of audiences with adventures of space exploration. Session four, "The Legacy of Carl Sagan," discusses the influences made by Sagan to scientific research and the general public. In session five, "Space Exploration for a new Generation," two student speakers and the NASA Administrator Daniel S. Goldin address the group. Session six, "Destiny or Delusion? -- Humankind's Place in the Cosmos," ends the symposium with issues of space exploration and some thought provoking questions. Some of these issues and questions are: what will be the societal implications if we discover the origin of the universe, stars, or life; what will be the impact if scientists find clear evidence of life outside the domains of the Earth; should there be limits to what humans can or should learn; and what visionary steps should space-faring people take now for future generations.

  4. Space debris: modeling and detectability

    Science.gov (United States)

    Wiedemann, C.; Lorenz, J.; Radtke, J.; Kebschull, C.; Horstmann, A.; Stoll, E.

    2017-01-01

    High precision orbit determination is required for the detection and removal of space debris. Knowledge of the distribution of debris objects in orbit is necessary for orbit determination by active or passive sensors. The results can be used to investigate the orbits on which objects of a certain size at a certain frequency can be found. The knowledge of the orbital distribution of the objects as well as their properties in accordance with sensor performance models provide the basis for estimating the expected detection rates. Comprehensive modeling of the space debris environment is required for this. This paper provides an overview of the current state of knowledge about the space debris environment. In particular non-cataloged small objects are evaluated. Furthermore, improvements concerning the update of the current space debris model are addressed. The model of the space debris environment is based on the simulation of historical events, such as fragmentations due to explosions and collisions that actually occurred in Earth orbits. The orbital distribution of debris is simulated by propagating the orbits considering all perturbing forces up to a reference epoch. The modeled object population is compared with measured data and validated. The model provides a statistical distribution of space objects, according to their size and number. This distribution is based on the correct consideration of orbital mechanics. This allows for a realistic description of the space debris environment. Subsequently, a realistic prediction can be provided concerning the question, how many pieces of debris can be expected on certain orbits. To validate the model, a software tool has been developed which allows the simulation of the observation behavior of ground-based or space-based sensors. Thus, it is possible to compare the results of published measurement data with simulated detections. This tool can also be used for the simulation of sensor measurement campaigns. It is

  5. Active Space Debris Removal System

    Directory of Open Access Journals (Sweden)

    Gabriele GUERRA

    2017-06-01

    Full Text Available Since the start of the space era, more than 5000 launches have been carried out, each carrying satellites for many disparate uses, such as Earth observation or communication. Thus, the space environment has become congested and the problem of space debris is now generating some concerns in the space community due to our long-lived belief that “space is big”. In the last few years, solutions to this problem have been proposed, one of those is Active Space Debris Removal: this method will reduce the increasing debris growth and permit future sustainable space activities. The main idea of the method proposed below is a drag augmentation system: use a system capable of putting an expanded foam on a debris which will increase the area-to-mass ratio to increase the natural atmospheric drag and solar pressure. The drag augmentation system proposed here requires a docking system; the debris will be pushed to its release height and then, after un-docking, an uncontrolled re-entry takes place ending with a burn up of the object and the foam in the atmosphere within a given time frame. The method requires an efficient way to change the orbit between two debris. The present paper analyses such a system in combination with an Electric Propulsion system, and emphasizes the choice of using two satellites to remove five effective rockets bodies debris within a year.

  6. Space Debris Mitigation CONOPS Development

    Science.gov (United States)

    2013-06-01

    literature search and review a lone article was found with any discussion of it. As with any net, the concept is to catch space debris objects in the net...travel along the track of the orbit and collect debris along its path. The lone article found contends that the idea “does not work”. Bonnal and...100,000 pieces of debris orbiting the planet , [as] NASA estimated -- 2,600 of them more than [four] inches across. [NASA] called the breakup of the

  7. Space Tourism: Orbital Debris Considerations

    Science.gov (United States)

    Mahmoudian, N.; Shajiee, S.; Moghani, T.; Bahrami, M.

    2002-01-01

    Space activities after a phase of research and development, political competition and national prestige have entered an era of real commercialization. Remote sensing, earth observation, and communication are among the areas in which this growing industry is facing competition and declining government money. A project like International Space Station, which draws from public money, has not only opened a window of real multinational cooperation, but also changed space travel from a mere fantasy into a real world activity. Besides research activities for sending man to moon and Mars and other outer planets, space travel has attracted a considerable attention in recent years in the form of space tourism. Four countries from space fairing nations are actively involved in the development of space tourism. Even, nations which are either in early stages of space technology development or just beginning their space activities, have high ambitions in this area. This is worth noting considering their limited resources. At present, trips to space are available, but limited and expensive. To move beyond this point to generally available trips to orbit and week long stays in LEO, in orbital hotels, some of the required basic transportations, living requirements, and technological developments required for long stay in orbit are already underway. For tourism to develop to a real everyday business, not only the price has to come down to meaningful levels, but also safety considerations should be fully developed to attract travelers' trust. A serious hazard to space activities in general and space tourism in particular is space debris in earth orbit. Orbiting debris are man-made objects left over by space operations, hazardous to space missions. Since the higher density of debris population occurs in low earth orbit, which is also the same orbit of interest to space tourism, a careful attention should be paid to the effect of debris on tourism activities. In this study, after a

  8. Space debris mitigation - engineering strategies

    Science.gov (United States)

    Taylor, E.; Hammond, M.

    The problem of space debris pollution is acknowledged to be of growing concern by space agencies, leading to recent activities in the field of space debris mitigation. A review of the current (and near-future) mitigation guidelines, handbooks, standards and licensing procedures has identified a number of areas where further work is required. In order for space debris mitigation to be implemented in spacecraft manufacture and operation, the authors suggest that debris-related criteria need to become design parameters (following the same process as applied to reliability and radiation). To meet these parameters, spacecraft manufacturers and operators will need processes (supported by design tools and databases and implementation standards). A particular aspect of debris mitigation, as compared with conventional requirements (e.g. radiation and reliability) is the current and near-future national and international regulatory framework and associated liability aspects. A framework for these implementation standards is presented, in addition to results of in-house research and development on design tools and databases (including collision avoidance in GTO and SSTO and evaluation of failure criteria on composite and aluminium structures).

  9. Space Debris and Observational Astronomy

    Science.gov (United States)

    Seitzer, Patrick

    2018-01-01

    Since the launch of Sputnik 1 in 1957, astronomers have faced an increasing number of artificial objects contaminating their images of the night sky. Currently almost 17000 objects larger than 10 cm are tracked and have current orbits in the public catalog. Active missions are only a small fraction of these objects. Most are inactive satellites, rocket bodies, and fragments of larger objects: all space debris. Several mega-constellations are planned which will increase this number by 20% or more in low Earth orbit (LEO). In terms of observational astronomy, this population of Earth orbiting objects has three implications: 1) the number of streaks and glints from spacecraft will only increase. There are some practical steps that can be taken to minimize the number of such streaks and glints in astronomical imaging data. 2) The risk to damage to orbiting astronomical telescopes will only increase, particularly those in LEO. 3) If you are working on a plan for an orbiting telescope project, then there are specific steps that must be taken to minimize space debris generation during the mission lifetime, and actions to safely dispose of the spacecraft at end of mission to prevent it from becoming space debris and a risk to other missions. These steps may involve sacrifices to mission performance and lifetime, but are essential in today's orbital environment.

  10. Space Debris Elimination (SpaDE)

    Data.gov (United States)

    National Aeronautics and Space Administration — The amount of debris in low Earth orbit (LEO) has increased rapidly over the last twenty years. This prevalence of debris increases the likelihood of cascading...

  11. Small satellites and space debris issues

    Science.gov (United States)

    Yakovlev, M.; Kulik, S.; Agapov, V.

    2001-10-01

    The objective of this report is the analysis of the tendencies in designing of small satellites (SS) and the effect of small satellites on space debris population. It is shown that SS to include nano- and pico-satellites should be considered as a particularly dangerous source of space debris when elaborating international standards and legal documents concerning the space debris problem, in particular "International Space Debris Mitigation Standard". These issues are in accordance with the IADC goals in its main activity areas and should be carefully considered within the IADC framework.

  12. New solutions for the space debris problem

    CERN Document Server

    Pelton, Joseph N

    2015-01-01

    Addressing a pressing issue in space policy, Pelton explores the new forms of technology that are being developed to actively remove the defunct space objects from orbit and analyzes their implications in the existing regime of international space law and public international law. This authoritative review covers the due diligence guidelines that nations are using to minimize the generation of new debris, mandates to de-orbit satellites at end of life, and innovative endeavours to remove non-functional satellites, upper stage rockets and other large debris from orbit under new institutional, financial and regulatory guidelines.  Commercial space services currently exceed 100 billion USD business per annum, but the alarming proliferation in the population of orbital debris in low, medium and geosynchronous satellite orbits poses a serious threat to all kinds of space assets and applications. There is a graver concern that the existing space debris will begin to collide in a cascading manner, generating furth...

  13. Space Debris Removal: A Game Theoretic Analysis

    Directory of Open Access Journals (Sweden)

    Richard Klima

    2016-08-01

    Full Text Available We analyse active space debris removal efforts from a strategic, game-theoretical perspective. Space debris is non-manoeuvrable, human-made objects orbiting Earth, which pose a significant threat to operational spacecraft. Active debris removal missions have been considered and investigated by different space agencies with the goal to protect valuable assets present in strategic orbital environments. An active debris removal mission is costly, but has a positive effect for all satellites in the same orbital band. This leads to a dilemma: each agency is faced with the choice between the individually costly action of debris removal, which has a positive impact on all players; or wait and hope that others jump in and do the ‘dirty’ work. The risk of the latter action is that, if everyone waits, the joint outcome will be catastrophic, leading to what in game theory is referred to as the ‘tragedy of the commons’. We introduce and thoroughly analyse this dilemma using empirical game theory and a space debris simulator. We consider two- and three-player settings, investigate the strategic properties and equilibria of the game and find that the cost/benefit ratio of debris removal strongly affects the game dynamics.

  14. The Third International Symposium on Space Terahertz Technology: Symposium proceedings

    Science.gov (United States)

    1992-01-01

    Papers from the symposium are presented that are relevant to the generation, detection, and use of the terahertz spectral region for space astronomy and remote sensing of the Earth's upper atmosphere. The program included thirteen sessions covering a wide variety of topics including solid-state oscillators, power-combining techniques, mixers, harmonic multipliers, antennas and antenna arrays, submillimeter receivers, and measurement techniques.

  15. Abstracts, Third Space Processing Symposium, Skylab results

    Science.gov (United States)

    1974-01-01

    Skylab experiments results are reported in abstracts of papers presented at the Third Space Processing Symposium. Specific areas of interest include: exothermic brazing, metals melting, crystals, reinforced composites, glasses, eutectics; physics of the low-g processes; electrophoresis, heat flow, and convection demonstrations flown on Apollo missions; and apparatus for containerless processing, heating, cooling, and containing materials.

  16. Laser space debris removal: now, not later

    Science.gov (United States)

    Phipps, Claude R.

    2015-02-01

    Small (1-10cm) debris in low Earth orbit (LEO) are extremely dangerous, because they spread the breakup cascade depicted in the movie "Gravity." Laser-Debris-Removal (LDR) is the only solution that can address both large and small debris. In this paper, we briefly review ground-based LDR, and discuss how a polar location can dramatically increase its effectiveness for the important class of sun-synchronous orbit (SSO) objects. No other solutions address the whole problem of large ( 1000cm, 1 ton) as well as small debris. Physical removal of small debris (by nets, tethers and so on) is impractical because of the energy cost of matching orbits. We also discuss a new proposal which uses a space-based station in low Earth orbit (LEO), and rapid, head-on interaction in 10- 40s rather than 4 minutes, with high-power bursts of 100ps, 355nm pulses from a 1.5m diameter aperture. The orbiting station employs "heat-capacity" laser mode with low duty cycle to create an adaptable, robust, dualmode system which can lower or raise large derelict objects into less dangerous orbits, as well as clear out the small debris in a 400-km thick LEO band. Time-average laser optical power is less than 15kW. The combination of short pulses and UV wavelength gives lower required energy density (fluence) on target as well as higher momentum coupling coefficient. This combination leads to much smaller mirrors and lower average power than the ground-based systems we have considered previously. Our system also permits strong defense of specific assets. Analysis gives an estimated cost of about 1k each to re-enter most small debris in a few months, and about 280k each to raise or lower 1-ton objects by 40km. We believe it can do this for 2,000 such large objects in about four years. Laser ablation is one of the few interactions in nature that propel a distant object without any significant reaction on the source.

  17. Net deployment and contact dynamics of capturing space debris objects

    NARCIS (Netherlands)

    Shan, M.

    2018-01-01

    Space debris poses a big threat to operational satellites which form a crucial infrastructure for society. According to the main source of information on space debris, the U.S. Space SurveillanceNetwork (SSN), more than 17 500 objects larger than 10 cmhave been catalogued as of February 2017. Among

  18. Space Debris Alert System for Aviation

    Science.gov (United States)

    Sgobba, Tommaso

    2013-09-01

    Despite increasing efforts to accurately predict space debris re-entry, the exact time and location of re-entry is still very uncertain. Partially, this is due to a skipping effect uncontrolled spacecraft may experience as they enter the atmosphere at a shallow angle. Such effect difficult to model depends on atmospheric variations of density. When the bouncing off ends and atmospheric re-entry starts, the trajectory and the overall location of surviving fragments can be precisely predicted but the time to impact with ground, or to reach the airspace, becomes very short.Different is the case of a functional space system performing controlled re-entry. Suitable forecasts methods are available to clear air and maritime traffic from hazard areas (so-called traffic segregation).In US, following the Space Shuttle Columbia accident in 2003, a re-entry hazard areas location forecast system was putted in place for the specific case of major malfunction of a Reusable Launch Vehicles (RLV) at re-entry. The Shuttle Hazard Area to Aircraft Calculator (SHAAC) is a system based on ground equipment and software analyses and prediction tools, which require trained personnel and close coordination between the organization responsible for RLV operation (NASA for Shuttle) and the Federal Aviation Administration. The system very much relies on the operator's capability to determine that a major malfunction has occurred.This paper presents a US pending patent by the European Space Agency, which consists of a "smart fragment" using a GPS localizer together with pre- computed debris footprint area and direct broadcasting of such hazard areas.The risk for aviation from falling debris is very remote but catastrophic. Suspending flight over vast swath of airspace for every re-entering spacecraft or rocket upper stage, which is a weekly occurrence, would be extremely costly and disruptive.The Re-entry Direct Broadcasting Alert System (R- DBAS) is an original merging and evolution of the Re

  19. Space Transportation System Liftoff Debris Mitigation Process Overview

    Science.gov (United States)

    Mitchell, Michael; Riley, Christopher

    2011-01-01

    Liftoff debris is a top risk to the Space Shuttle Vehicle. To manage the Liftoff debris risk, the Space Shuttle Program created a team with in the Propulsion Systems Engineering & Integration Office. The Shutt le Liftoff Debris Team harnesses the Systems Engineering process to i dentify, assess, mitigate, and communicate the Liftoff debris risk. T he Liftoff Debris Team leverages off the technical knowledge and expe rtise of engineering groups across multiple NASA centers to integrate total system solutions. These solutions connect the hardware and ana lyses to identify and characterize debris sources and zones contribut ing to the Liftoff debris risk. The solutions incorporate analyses sp anning: the definition and modeling of natural and induced environmen ts; material characterizations; statistical trending analyses, imager y based trajectory analyses; debris transport analyses, and risk asse ssments. The verification and validation of these analyses are bound by conservative assumptions and anchored by testing and flight data. The Liftoff debris risk mitigation is managed through vigilant collab orative work between the Liftoff Debris Team and Launch Pad Operation s personnel and through the management of requirements, interfaces, r isk documentation, configurations, and technical data. Furthermore, o n day of launch, decision analysis is used to apply the wealth of ana lyses to case specific identified risks. This presentation describes how the Liftoff Debris Team applies Systems Engineering in their proce sses to mitigate risk and improve the safety of the Space Shuttle Veh icle.

  20. Aerogels Materials as Space Debris Collectors

    Directory of Open Access Journals (Sweden)

    Thierry Woignier

    2013-01-01

    Full Text Available Material degradation due to the specific space environment becomes a key parameter for space missions. The use of large surface of brittle materials on satellites can produce, if impacted by hypervelocity particles, ejected volumes of mater 100 times higher than the impacting one. The presented work is devoted to the use of silica aerogels as passive detectors. Aerogels have been exposed to the low earth orbit of the ISS for 18 months. The study describes the aerogels process and the choice of synthesis parameters in such a way to get expected features in terms of porosity, mechanical properties, internal stresses, and transparency. Low-density aerogels (0.09 g·cm−3 have been prepared. The control of transparency necessary to see and identify particles and fragments collected is obtained using a base catalysis during gel synthesis. After return to earth, the aerogels samples have been observed using optical microscopy to detect and quantify craters on the exposed surface. First results obtained on a small part of the aerogels indicate a large number of debris collected in the materials.

  1. Center for Advanced Space Propulsion Second Annual Technical Symposium Proceedings

    Science.gov (United States)

    1990-01-01

    The proceedings for the Center for Advanced Space Propulsion Second Annual Technical Symposium are divided as follows: Chemical Propulsion, CFD; Space Propulsion; Electric Propulsion; Artificial Intelligence; Low-G Fluid Management; and Rocket Engine Materials.

  2. Analysis of a space debris laser removal system

    Science.gov (United States)

    Gjesvold, Evan; Straub, Jeremy

    2017-05-01

    As long as man ventures into space, he will leave behind debris, and as long as he ventures into space, this debris will pose a threat to him and his projects. Space debris must be located and decommissioned. Lasers may prove to be the ideal method, as they can operate at a distance from the debris, have a theoretically infinite supply of energy from the sun, and are a seemingly readily available technology. This paper explores the requirements and reasoning for such a laser debris removal method. A case is made for the negligibility of eliminating rotational velocity from certain systems, while a design schematic is also presented for the implementation of a cube satellite proof of concept.

  3. First laser measurements to space debris in Poland

    Science.gov (United States)

    Lejba, Paweł; Suchodolski, Tomasz; Michałek, Piotr; Bartoszak, Jacek; Schillak, Stanisław; Zapaśnik, Stanisław

    2018-05-01

    The Borowiec Satellite Laser Ranging station (BORL 7811, Borowiec) being a part of the Space Research Centre of the Polish Academy of Sciences (SRC PAS) went through modernization in 2014-2015. One of the main tasks of the modernization was the installation of a high-energy laser module dedicated to space debris tracking. Surelite III by Continuum is a Nd:YAG pulse laser with 10 Hz repetition rate, a pulse width of 3-5 ns and a pulse energy of 450 mJ for green (532 nm). This new laser unit was integrated with the SLR system at Borowiec performing standard satellite tracking. In 2016 BORL 7811 participated actively to the observational campaigns related to the space debris targets from LEO region managed by the Space Debris Study Group (SDSG) of the International Laser Ranging Service (ILRS). Currently, Borowiec station regularly tracks 36 space debris from the LEO regime, including typical rocket bodies (Russian/Chinese) and cooperative targets like the inactive TOPEX/Poseidon, ENVISAT, OICETS and others. In this paper the first results of space debris laser measurements obtained by the Borowiec station in period August 2016 - January 2017 are presented. The results gained by the SRC PAS Borowiec station confirm the rotation of the defunct TOPEX/Poseidon satellite which spins with a period of approximately 10 s. The novelty of this work is the presentation of the sample results of the Chinese CZ-2C R/B target (NORAD catalogue number 31114) which is equipped (probably) with retroreflectors. Laser measurements to space debris is a very desirable topic for the next years, especially in the context of the Space Surveillance and Tracking (SST) activity. Some targets are very easy to track like defunct ENVISAT or TOPEX/Poseidon. On the other hand, there is a big population of different LEO targets with different orbital and physical parameters, which are challenging for laser ranging like small irregular debris and rocket boosters.

  4. USA Space Debris Environment, Operations, and Research Updates

    Science.gov (United States)

    Liou, J.-C.

    2018-01-01

    Space Missions in 2017 Earth Satellite Population Collision Avoidance Maneuvers Post mission Disposal of U.S.A. Spacecraft Space Situational Awareness (SSA) and the Space Debris Sensor (SDS) A total of 86 space launches placed more than 400 spacecraft into Earth orbits during 2017, following the trend of increase over the past decade NASA has established conjunction assessment processes for its human spaceflight and uncrewed spacecraft to avoid accidental collisions with objects tracked by the U.S. Space Surveillance Network - NASA also assists other U.S. government spacecraft owners with conjunction assessments and subsequent maneuvers The ISS has conducted 25 debris collision avoidance maneuvers since 1999 - None in 2016-2017, but an ISS visiting vehicle had one collision avoidance maneuver in 2017 During 2017 NASA executed or assisted in the execution of 21 collision avoidance maneuvers by uncrewed spacecraft - Four maneuvers were conducted to avoid debris from Fengyun-1C - Two maneuvers were conducted to avoid debris from the collision of Cosmos 2251 and Iridium 33 - One maneuver was conducted to avoid the ISS NASA has established conjunction assessment processes for its human spaceflight and uncrewed spacecraft to avoid accidental collisions with objects tracked by the U.S. Space Surveillance Network - NASA also assists other U.S. government spacecraft owners with conjunction assessments and subsequent maneuvers The ISS has conducted 25 debris collision avoidance maneuvers since 1999 - None in 2016-2017, but an ISS visiting vehicle had one collision avoidance maneuver in 2017 During 2017 NASA executed or assisted in the execution of 21 collision avoidance maneuvers by uncrewed spacecraft - Four maneuvers were conducted to avoid debris from Fengyun-1C - Two maneuvers were conducted to avoid debris from the collision of Cosmos 2251 and Iridium 33 The 2014-15 NASA Engineering and Safety Center (NESC) study on the micrometeoroid and orbital debris (MMOD

  5. Transactions of the fifth symposium on space nuclear power systems

    Energy Technology Data Exchange (ETDEWEB)

    El-Genk, M.S.; Hoover, M.D. (eds.)

    1988-01-01

    This paper contains the presented papers at the fourth symposium on space nuclear power systems. Topics of these paper include: space nuclear missions and applications, reactors and shielding, nuclear electric and nuclear propulsion, high-temperature materials, instrumentation and control, energy conversion and storage, space nuclear fuels, thermal management, nuclear safety, simulation and modeling, and multimegawatt system concepts. (LSP)

  6. Transactions of the fourth symposium on space nuclear power systems

    Energy Technology Data Exchange (ETDEWEB)

    El-Genk, M.S.; Hoover, M.D. (eds.)

    1987-01-01

    This paper contains the presented papers at the fourth symposium on space nuclear power systems. Topics of these papers include: space nuclear missions and applications, reactors and shielding, nuclear electric and nuclear propulsion, refractory alloys and high-temperature materials, instrumentation and control, energy conversion and storage, space nuclear fuels, thermal management, nuclear safety, simulation and modeling, and multimegawatt system concepts. (LSP)

  7. Apparent rotation properties of space debris extracted from photometric measurements

    Science.gov (United States)

    Šilha, Jiří; Pittet, Jean-Noël; Hamara, Michal; Schildknecht, Thomas

    2018-02-01

    Knowledge about the rotation properties of space debris objects is essential for the active debris removal missions, accurate re-entry predictions and to investigate the long-term effects of the space environment on the attitude motion change. Different orbital regions and object's physical properties lead to different attitude states and their change over time. Since 2007 the Astronomical Institute of the University of Bern (AIUB) performs photometric measurements of space debris objects. To June 2016 almost 2000 light curves of more than 400 individual objects have been acquired and processed. These objects are situated in all orbital regions, from low Earth orbit (LEO), via global navigation systems orbits and high eccentricity orbit (HEO), to geosynchronous Earth orbit (GEO). All types of objects were observed including the non-functional spacecraft, rocket bodies, fragmentation debris and uncorrelated objects discovered during dedicated surveys. For data acquisition, we used the 1-meter Zimmerwald Laser and Astrometry Telescope (ZIMLAT) at the Swiss Optical Ground Station and Geodynamics Observatory Zimmerwald, Switzerland. We applied our own method of phase-diagram reconstruction to extract the apparent rotation period from the light curve. Presented is the AIUB's light curve database and the obtained rotation properties of space debris as a function of object type and orbit.

  8. Changes of Space Debris Orbits After LDR Operation

    Science.gov (United States)

    Wnuk, E.; Golebiewska, J.; Jacquelard, C.; Haag, H.

    2013-09-01

    A lot of technical studies are currently developing concepts of active removal of space debris to protect space assets from on orbit collision. For small objects, such concepts include the use of ground-based lasers to remove or reduce the momentum of the objects thereby lowering their orbit in order to facilitate their decay by re-entry into the Earth's atmosphere. The concept of the Laser Debris Removal (LDR) system is the main subject of the CLEANSPACE project. One of the CLEANSPACE objectives is to define a global architecture (including surveillance, identification and tracking) for an innovative ground-based laser solution, which can remove hazardous medium debris around selected space assets. The CLEANSPACE project is realized by a European consortium in the frame of the European Commission Seventh Framework Programme (FP7), Space topic. The use of sequence of laser operations to remove space debris, needs very precise predictions of future space debris orbital positions, on a level even better than 1 meter. Orbit determination, tracking (radar, optical and laser) and orbit prediction have to be performed with accuracy much better than so far. For that, the applied prediction tools have to take into account all perturbation factors that influence object orbit. The expected object's trajectory after the LDR operation is a lowering of its perigee. To prevent the debris with this new trajectory to collide with another object, a precise trajectory prediction after the LDR sequence is therefore the main task allowing also to estimate re-entry parameters. The LDR laser pulses change the debris object velocity v. The future orbit and re-entry parameters of the space debris after the LDR engagement can be calculated if the resulting ?v vector is known with the sufficient accuracy. The value of the ?v may be estimated from the parameters of the LDR station and from the characteristics of the orbital debris. However, usually due to the poor knowledge of the debris

  9. 3rd Symposium on Space Optical Instruments and Applications

    CERN Document Server

    Zhang, Guangjun

    2017-01-01

    This volume contains selected and expanded contributions presented at the 3rd Symposium on Space Optical Instruments and Applications in Beijing, China June 28 – 29, 2016. This conference series is organised by the Sino-Holland Space Optical Instruments Laboratory, a cooperation platform between China and the Netherlands. The symposium focused on key technological problems of optical instruments and their applications in a space context. It covered the latest developments, experiments and results regarding theory, instrumentation and applications in space optics. The book is split across five topical sections. The first section covers space optical remote sensing system design, the second advanced optical system design, the third remote sensor calibration and measurement. Remote sensing data processing and information extraction is then presented, followed by a final section on remote sensing data applications. .

  10. Comparison of Space Debris Environment Models: ORDEM2000, MASTER-2001, MASTER-2005 and MASTER-2009

    OpenAIRE

    Kanemitsu, Yuki; 赤星, 保浩; Akahoshi, Yasuhiro; 鳴海, 智博; Narumi, Tomohiro; Faure, Pauline; 松本, 晴久; Matsumoto, Haruhisa; 北澤, 幸人; Kitazawa, Yukihito

    2012-01-01

    Hypervelocity impact by space debris on spacecraft is one of the most important issues for space development and operation, especially considering the growing amount of space debris in recent years. It is therefore important for spacecraft design to evaluate the impact risk by using environment models. In this paper, the authors compared the results of the debris impact flux in low Earth orbit, as calculated by four debris environment engineering models -NASA's ORDEM2000 and ESA's MASTER-2001...

  11. Statistical learning modeling method for space debris photometric measurement

    Science.gov (United States)

    Sun, Wenjing; Sun, Jinqiu; Zhang, Yanning; Li, Haisen

    2016-03-01

    Photometric measurement is an important way to identify the space debris, but the present methods of photometric measurement have many constraints on star image and need complex image processing. Aiming at the problems, a statistical learning modeling method for space debris photometric measurement is proposed based on the global consistency of the star image, and the statistical information of star images is used to eliminate the measurement noises. First, the known stars on the star image are divided into training stars and testing stars. Then, the training stars are selected as the least squares fitting parameters to construct the photometric measurement model, and the testing stars are used to calculate the measurement accuracy of the photometric measurement model. Experimental results show that, the accuracy of the proposed photometric measurement model is about 0.1 magnitudes.

  12. 12th Man in Space Symposium: The Future of Humans in Space. Abstract Volume

    Science.gov (United States)

    1997-01-01

    The National Aeronautics and Space Administration (NASA) is pleased to host the 12th IAA Man in Space Symposium. A truly international forum, this symposium brings together scientists, engineers, and managers interested in all aspects of human space flight to share the most recent research results and space agency planning related to the future of humans in space. As we look out at the universe from our own uniquely human perspective, we see a world that we affect at the same time that it affects us. Our tomorrows are highlighted by the possibilities generated by our knowledge, our drive, and our dreams. This symposium will examine our future in space from the springboard of our achievements.

  13. Development of Harpoon System for Capturing Space Debris

    Science.gov (United States)

    Reed, Jame; Barraclough, Simon

    2013-08-01

    Active removal of large space debris has been identified as a key activity to control the growth in the debris population and to limit the risk to active satellites. Astrium is developing technologies to enable such a mission, including a harpoon capture system. The harpoon is simple, compact and lightweight. Since the capture is fast (typically barbs to robustly hold the target, a crushable section to absorb excess impact energy, and a tether to connect to the chaser vehicle. The baseline firing system uses compressed gas, although a simpler one-shot system has also been designed. To understand how a harpoon could be applicable to active debris removal an on-ground prototype and test-rig has been developed for trials with real structural elements of satellites and rocket bodies. Testing has demonstrated the feasibility of the concept and this paper describes the results as well as the next steps. A number of design variants are also proposed which could simplify the system design of an ADR mission.

  14. Review of the Space Debris Protection Application on ``TIANGONG-1''

    Science.gov (United States)

    Zhang, Yong; Li, Ming; Han, Zengyao

    Meteoroid and orbital debris (M/OD) is the key factor related to the astronaut safety. The long-term manned spacelab generally adopts protection measures to reduce its hypervelocity impact (HVI) risk. This paper presents the engineering application on“Tiangong-1”,the first long-term spacelab in orbit for China.The application includes the M/OD shielding, active avoidance and mitigation. Firstly, the shielding concepts on“Tiangong-1”manned module and radiator are summarized. Two typical Whipple shields respectively with the 70mm and 50mm standoff are separately utilized for the front cone and cylinder pressurized walls. The ballistic limit Equations (BLE) of these two shieldings are achieved through the HVI tests and numerical simulation. The shields provide the resistance capability of space debris particle.Meanwhile, the M/OD risk is assessed by utilizing the MODAOST to predict the probability of penetration (PP) and probability of critical failure (PCF). The assessment shows that the shielding design meets the safety requirement with the PP of 2.09X10 (-3) and the critical cracking PCF of 3.35X10 (-4) . The radiator,the large-scaled component of manned Spacelab, adopts the Ω-shaped tube to improve the HVI resistance capability with the cost of less mass. Secondly, the orbit transfer strategy is designed not only to meet the requirement of the orbit phase of “Shenzhou” spacecraft but also actively avoid the rendezvous with the cataloged debris in orbit. This strategy is validated through the rendezvous and docking missions of “Shenzhou-8” and “Tiangong-1”,“Shenzhou-9”,“Shenzhou-10”. Thirdly, the mitigation and deactivation concepts are introduced by means of reentry simulation of “Tiangong-1” to protect the space environment and reduce the ground casualty. The space debris protection techniques applied on “Tiangong-1” have been broken through with the successful mission of “Tiangong-1”, and these applied techniques provide

  15. Simulation analysis of impulse characteristics of space debris irradiated by multi-pulse laser

    Science.gov (United States)

    Lin, Zhengguo; Jin, Xing; Chang, Hao; You, Xiangyu

    2018-02-01

    Cleaning space debris with laser is a hot topic in the field of space security research. Impulse characteristics are the basis of cleaning space debris with laser. In order to study the impulse characteristics of rotating irregular space debris irradiated by multi-pulse laser, the impulse calculation method of rotating space debris irradiated by multi-pulse laser is established based on the area matrix method. The calculation method of impulse and impulsive moment under multi-pulse irradiation is given. The calculation process of total impulse under multi-pulse irradiation is analyzed. With a typical non-planar space debris (cube) as example, the impulse characteristics of space debris irradiated by multi-pulse laser are simulated and analyzed. The effects of initial angular velocity, spot size and pulse frequency on impulse characteristics are investigated.

  16. Legal Consequences of the Pollution of Outer Space with Space Debris

    Science.gov (United States)

    Stubbe, Peter

    2017-07-01

    Space debris has grown to be a significant problem for outer space activities. The remnants of human activities in space are very diverse; they can be tiny paint flakes, all sorts of fragments, or entirely intact—but otherwise nonfunctional spacecraft and rocket bodies. The amount of debris is increasing at a growing pace, thus raising the risk of collision with operational satellites. Due to the relative high velocities involved in on-orbit collisions, their consequences are severe; collisions lead to significant damage or the complete destruction of the affected spacecraft. Protective measures and collision avoidance have thus become a major concern for spacecraft operators. The pollution of space with debris must, however, not only be seen as an unfavorable circumstance that accompanies space activities and increases the costs and complexity of outer space activities. Beyond this rather technical perspective, the presence of man-made, nonfunctional objects in space represents a global environmental concern. Similar to the patterns of other environmental problems on Earth, debris generation appears to have surpassed the absorption capacity of the space environment. Studies indicate that the evolution of the space object environment has crossed the tipping point to a runaway situation in which an increasing number of collisions―mostly among debris―leads to an uncontrolled population growth. It is thus in the interest of all mankind to address the debris problem in order to preserve the space environment for future generations. International space law protects the space environment. Article IX of the Outer Space Treaty obligates States to avoid the harmful contamination of outer space. The provision corresponds to the obligation to protect the environment in areas beyond national jurisdiction under the customary "no harm" rule of general environmental law. These norms are applicable to space debris and establish the duty not to pollute outer space by limiting

  17. Micro-satellite for space debris observation by optical sensors

    Science.gov (United States)

    Thillot, Marc; Brenière, Xavier; Midavaine, Thierry

    2017-11-01

    The purpose of this theoretical study carried out under CNES contract is to analyze the feasibility of small space debris detection and classification with an optical sensor on-board micro-satellite. Technical solutions based on active and passive sensors are analyzed and compared. For the most appropriated concept an optimization was made and theoretical performances in terms of number of detection versus class of diameter were calculated. Finally we give some preliminary physical sensor features to illustrate the concept (weight, volume, consumption,…).

  18. Image processing improvement for optical observations of space debris with the TAROT telescopes

    Science.gov (United States)

    Thiebaut, C.; Theron, S.; Richard, P.; Blanchet, G.; Klotz, A.; Boër, M.

    2016-07-01

    CNES is involved in the Inter-Agency Space Debris Coordination Committee (IADC) and is observing space debris with two robotic ground based fully automated telescopes called TAROT and operated by the CNRS. An image processing algorithm devoted to debris detection in geostationary orbit is implemented in the standard pipeline. Nevertheless, this algorithm is unable to deal with debris tracking mode images, this mode being the preferred one for debris detectability. We present an algorithm improvement for this mode and give results in terms of false detection rate.

  19. Kent in space: Cosmic dust to space debris

    Science.gov (United States)

    McDonnell, J. A. M.

    1994-10-01

    The dusty heritage of the University of Kent's Space Group commenced at Jodrell Bank, Cheshire, U.K., the home of the largest steerable radio telescope. While Professor Bernard Lovell's 250 ft. diameter telescope was used to command the U.S. deep space Pioneer spacecraft, Professor Tony McDonnell, as a research student in 1960, was developing a space dust detector for the US-UK Ariel program. It was successful. With a Ph.D. safely under the belt, it seemed an inevitable step to go for the next higher degree, a B.T.A.] Two years with NASA at Goddard Space Flight Center, Greenbelt, provided excellent qualifications for such a graduation ('Been to America'). A spirited return to the University of Kent at Canterbury followed, to one of the green field UK University sites springing from the Robbins Report on Higher Education. Swimming against the current of the brain drain, and taking a very considerable reduction in salary, it was with some disappointment that he found that the UK Premier Harold Wilson's 'white-hot technological revolution' never quite seemed to materialize in terms of research funding] Research expertise, centered initially on cosmic dust, enlarged to encompass planetology during the Apollo program, and rightly acquired international acclaim, notching up a history of space missions over 25 years. The group now comprises 38 people supported by four sources: the government's Research Councils, the University, the Space Agencies and Industry. This paper describes the thrust of the group's Research Plan in Space Science and Planetology; not so much based on existing international space missions, but more helping to shape the direction and selection of space missions ahead.

  20. Attitude Motion of Cylindrical Space Debris during Its Removal by Ion Beam

    Directory of Open Access Journals (Sweden)

    Vladimir S. Aslanov

    2017-01-01

    Full Text Available The paper is devoted to the problem of space debris mitigation. Contactless method of the space debris deorbiting is considered. It is assumed that ion thrusters on the active spacecraft create the ion flow, which blows the debris and slows it down. The objectives of this work are the development of mathematical models and the research of space debris motion under the action of the ion flow. It is supposed that the space debris is a rigid body of a cylindrical shape. Calculation of ion beam force and torque was performed for a self-similar model of plasma plume expansion using the hypothesis of ion fully diffused reflection from a surface. A mathematical model describing plane motions of the cylindrical space debris under the influence of gravity gradient torque and the ion flux was constructed. It was shown that motion of the space debris around its center of mass has a significant effect on its removal time. Phase portraits, describing the motion of the space debris relative to its center of mass, were constructed. Comparison of the descent times in different motion modes was carried out. The results can be used to create new effective systems of large space debris removal.

  1. The geocentric particulate distribution: Cometary, asteroidal, or space debris?

    Science.gov (United States)

    Mcdonnell, J. A. M.; Ratcliff, P. R.

    1992-01-01

    Definition of the Low Earth Orbit (LEO) particulate environment has been refined considerably with the analysis of data from NASA's Long Duration Exposure Facility (LDEF). Measurements of the impact rates from particulates ranging from sub-micron to millimetres in dimension and, especially, information on their directionality has permitted new scrunity of the sources of the particulates. Modelling of the dynamics of both bound (Earth orbital) and unbound (hyperbolic interplanetary) particulates intercepting LDEF's faces leads to the conclusion that the source is dominantly interplanetary for particle dimensions of greater than some 5 microns diameter; however the anisotropy below this dimension demands lower velocities and is compatible with an orbital component. Characteristics of the LDEF interplanetary component are compatible with familiar meteoroid sources and deep space measurements. Understanding of the orbital component which exceeds the interplanetary flux by a factor of 4 is less clear; although the very small particulates in orbit have been associated with space debris (Lawrance and Brownlee, 1986) this data conflicts with other measurements (McDonnell, Carey and Dixon, 1984) at the same epoch. By analysis of trajectories approaching the Earth and its atmosphere, we have shown that a significant contribution could be captured by aerocapture, i.e., atmospheric drag, from either asteroidal or cometary sources; such enhancement is unlikely however to provide the temporal and spatial fluctuations observed by the LDEF Interplanetary Dust Experiment (Mullholland et al. 1992). A further new mechanism is also examined, that of aerofragmentation capture, where an atmospheric grazing trajectory, which would not normally lead to capture, leads to fragmentation by thermal or mechanical shock; the microparticulates thus created can be injected in large numbers, but only into short-lifetime orbits. The concentration in one particular orbit plane, could explain the

  2. Space Debris Attitude Simulation - IOTA (In-Orbit Tumbling Analysis)

    Science.gov (United States)

    Kanzler, R.; Schildknecht, T.; Lips, T.; Fritsche, B.; Silha, J.; Krag, H.

    Today, there is little knowledge on the attitude state of decommissioned intact objects in Earth orbit. Observational means have advanced in the past years, but are still limited with respect to an accurate estimate of motion vector orientations and magnitude. Especially for the preparation of Active Debris Removal (ADR) missions as planned by ESA's Clean Space initiative or contingency scenarios for ESA spacecraft like ENVISAT, such knowledge is needed. The In-Orbit Tumbling Analysis tool (IOTA) is a prototype software, currently in development within the framework of ESA's “Debris Attitude Motion Measurements and Modelling” project (ESA Contract No. 40000112447), which is led by the Astronomical Institute of the University of Bern (AIUB). The project goal is to achieve a good understanding of the attitude evolution and the considerable internal and external effects which occur. To characterize the attitude state of selected targets in LEO and GTO, multiple observation methods are combined. Optical observations are carried out by AIUB, Satellite Laser Ranging (SLR) is performed by the Space Research Institute of the Austrian Academy of Sciences (IWF) and radar measurements and signal level determination are provided by the Fraunhofer Institute for High Frequency Physics and Radar Techniques (FHR). Developed by Hyperschall Technologie Göttingen GmbH (HTG), IOTA will be a highly modular software tool to perform short- (days), medium- (months) and long-term (years) propagation of the orbit and attitude motion (six degrees-of-freedom) of spacecraft in Earth orbit. The simulation takes into account all relevant acting forces and torques, including aerodynamic drag, solar radiation pressure, gravitational influences of Earth, Sun and Moon, eddy current damping, impulse and momentum transfer from space debris or micro meteoroid impact, as well as the optional definition of particular spacecraft specific influences like tank sloshing, reaction wheel behaviour

  3. Utilizing Weather RADAR for Rapid Location of Meteorite Falls and Space Debris Re-Entry

    Science.gov (United States)

    Fries, Marc D.

    2016-01-01

    This activity utilizes existing NOAA weather RADAR imagery to locate meteorite falls and space debris falls. The near-real-time availability and spatial accuracy of these data allow rapid recovery of material from both meteorite falls and space debris re-entry events. To date, at least 22 meteorite fall recoveries have benefitted from RADAR detection and fall modeling, and multiple debris re-entry events over the United States have been observed in unprecedented detail.

  4. Waste management in space: a NASA symposium. Special issue

    Science.gov (United States)

    Wydeven, T. (Principal Investigator)

    1991-01-01

    This special issue contains papers from the NASA Symposium on Waste Processing for Advanced Life Support, which was held at NASA Ames Research Center on September 11-13, 1990. Specialists in waste management from academia, government, and industry convened to exchange ideas and advise NASA in developing effective methods for waste management in a Controlled Ecological Life Support System (CELSS). Innovative and well-established methods were presented to assist in developing and managing wastes in closed systems for future long-duration space missions, especially missions to Mars.

  5. On the effects of solar storms to the decaying orbital space debris

    International Nuclear Information System (INIS)

    Herdiwijaya, Dhani; Rachman, Abdul

    2014-01-01

    Any man-made object in Earth's orbit that no longer serves a useful purpose is classified as orbital debris. Debris objects come from a variety of sources. The majority is related to satellite fragmentation. Other major sources of debris are propulsion systems, and fragmentation of spent upper stages, payload and mission related debris. Serious concern about orbital debris has been growing. Knowledge of the future debris environment is important to both satellite designers, and mission planners, who need to know what hazards a satellite might encounter during the course of its mission. Therefore, it is important to know how much debris is in orbit, where it is located, and when it will decay. The debris environment is complex and dynamically evolving. Objects of different shape and size behave differently in orbit. The geoeffectiveness space environments include solar flux at 10.7 cm, solar energetic particles flux or speed, solar wind flow pressure, electric field, and geomagnetic indices. We study the decaying orbital debris from Tracking and Impact Prediction (TIP) messages in conjuction with geoeffectiveness space environments through time epoch correlation. We found that the decaying and reentry orbital debris are triggered by space environment enhancement within at least one week before reentry. It is not necessary a transient or high energetic and severe solar storm events are needed in decaying processes. We propose that the gradual enhancement processes of space environment will cause satellite surface charging due to energetic electron and enhance drag force

  6. On the effects of solar storms to the decaying orbital space debris

    Energy Technology Data Exchange (ETDEWEB)

    Herdiwijaya, Dhani, E-mail: dhani@as.itb.ac.id [Astronomy Division and Bosscha Observatory, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Ganesha 10, Bandung 40132 (Indonesia); Rachman, Abdul [Space Science Center, National Institute of Aeronautics and Space, Junjunan 133, Bandung 40173 (Indonesia)

    2014-03-24

    Any man-made object in Earth's orbit that no longer serves a useful purpose is classified as orbital debris. Debris objects come from a variety of sources. The majority is related to satellite fragmentation. Other major sources of debris are propulsion systems, and fragmentation of spent upper stages, payload and mission related debris. Serious concern about orbital debris has been growing. Knowledge of the future debris environment is important to both satellite designers, and mission planners, who need to know what hazards a satellite might encounter during the course of its mission. Therefore, it is important to know how much debris is in orbit, where it is located, and when it will decay. The debris environment is complex and dynamically evolving. Objects of different shape and size behave differently in orbit. The geoeffectiveness space environments include solar flux at 10.7 cm, solar energetic particles flux or speed, solar wind flow pressure, electric field, and geomagnetic indices. We study the decaying orbital debris from Tracking and Impact Prediction (TIP) messages in conjuction with geoeffectiveness space environments through time epoch correlation. We found that the decaying and reentry orbital debris are triggered by space environment enhancement within at least one week before reentry. It is not necessary a transient or high energetic and severe solar storm events are needed in decaying processes. We propose that the gradual enhancement processes of space environment will cause satellite surface charging due to energetic electron and enhance drag force.

  7. Evasive Maneuvers in Space Debris Environment and Technological Parameters

    Directory of Open Access Journals (Sweden)

    Antônio D. C. Jesus

    2012-01-01

    Full Text Available We present a study of collisional dynamics between space debris and an operational vehicle in LEO. We adopted an approach based on the relative dynamics between the objects on a collisional course and with a short warning time and established a semianalytical solution for the final trajectories of these objects. Our results show that there are angular ranges in 3D, in addition to the initial conditions, that favor the collisions. These results allowed the investigation of a range of technological parameters for the spacecraft (e.g., fuel reserve that allow a safe evasive maneuver (e.g., time available for the maneuver. The numerical model was tested for different values of the impact velocity and relative distance between the approaching objects.

  8. Resonant Orbital Dynamics in LEO Region: Space Debris in Focus

    Directory of Open Access Journals (Sweden)

    J. C. Sampaio

    2014-01-01

    Full Text Available The increasing number of objects orbiting the earth justifies the great attention and interest in the observation, spacecraft protection, and collision avoidance. These studies involve different disturbances and resonances in the orbital motions of these objects distributed by the distinct altitudes. In this work, objects in resonant orbital motions are studied in low earth orbits. Using the two-line elements (TLE of the NORAD, resonant angles and resonant periods associated with real motions are described, providing more accurate information to develop an analytical model that describes a certain resonance. The time behaviors of the semimajor axis, eccentricity, and inclination of some space debris are studied. Possible irregular motions are observed by the frequency analysis and by the presence of different resonant angles describing the orbital dynamics of these objects.

  9. ISU Team Project: An Integral View on Space Debris Mitigation and Removal

    Science.gov (United States)

    Maier, Philipp; Ricote Navarro, Carmon; Jehn, Rudiger; Gini, Andrea; Faure, Pauline; Adriaensen, Maarten; Datta, Iman; Hilbich, Daniel; Jacimovic, Aleksandar; Jacques, Lionel; Penent, Guilhem; Sinn, Thomas; Shioi, Hiroaki

    2013-08-01

    The issue of space debris poses challenges not only in technical, but also legal, political and economic dimensions. A sustainable solution needs to take into account all of them. This paper investigates such a potential solution in a multidisciplinary approach. To this end, it addresses the effectiveness of the existing debris mitigation guidelines, and identifies technical improvements for mitigation. It continues examining technical concepts for debris removal and performing proper cost-benefit trade-offs. The results of new simulations to assess the damage cost caused by space debris are presented. Based on these findings, an organizational framework and political recommendations are developed which will enable a sustainable use of space starting in 2020. The findings are compiled into a roadmap, which outlines 1) a path to the full adherence to debris mitigation guidelines and 2) the removal of ten large pieces of debris per year by a dedicated international organization, including expected expenditures necessary for its implementation.

  10. 41st symposium of the European Space Agency

    CERN Document Server

    Macchetto, F Duccio

    2010-01-01

    The Hubble Space Telescope has facilitated major contributions to a wide range of topics in astronomy: The study of nearby planets The processes of star and planet formation The stellar and interstellar components of galaxies The discovery that most, if not all, galactic nuclei harbor a massive black hole that profoundly affects their evolution The realisation that the universe as a whole is undergoing acceleration as a result of a yet unknown form of "dark energy". This volume offers a broad perspective of the advancements made possible by the HST over its almost two decades of operation and emphasises their impact on European astronomical research. These proceedings of 41st symposium in the ESLAB series of the European Space Agency collect the oral and poster papers that were presented and discussed during the meeting.

  11. Prediction of HAMR Debris Population Distribution Released from GEO Space

    Science.gov (United States)

    Rosengren, A.; Scheeres, D.

    2012-09-01

    The high area-to-mass ratio (HAMR) debris population is thought to have origins in the GEO region. Many of these objects are uncharacterized with apparent area-to-mass ratios of up to 30 meters squared per kilogram. The orbits of HAMR objects are highly perturbed due to the combined effect of solar radiation pressure (SRP), anomalies of the Earth gravitational field, and third-body gravitational interactions induced by the Sun and the Moon. A sound understanding of their nature, orbital evolution, and possible origin is critical for space situational awareness. The study of the orbital evolution of HAMR objects, taking into account both short-period and long-period terms, requires numerical integration of the precise set of differential equations, and the investigation of a broad range of possible parameter values. However, such computations become very costly when continuously applied over a period of several decades, as is necessary in the case of HAMR debris. It therefore seems reasonable to investigate the equations that govern the long-term behavior of orbits; such equations can be derived by the method of averaging. We have validated a semi-analytical averaged theory of HAMR object orbit evolution against high precision numerical integrations, and are able to capture the extreme dynamical behaviors reported for these objects. This new averaged model, explicitly given in terms of the eccentricity and angular momentum vectors, is several hundred times faster to numerically integrate than the non-averaged Newtonian counterpart, and provides a very accurate description of the long-term behavior. Using this model, it is possible to make predictions of how a population of HAMR objects, released into GEO orbit, will evolve over time. Our earlier analyses revealed that the population would have a range of orbits much different than circular GEO. Their orbits will suffer a sub-yearly oscillation in the eccentricity and inclination evolutions, and a longer-term drift

  12. UniSat-5: a space-based optical system for space debris monitoring

    Science.gov (United States)

    Di Roberto, Riccardo; Cappelletti, Chantal

    2012-07-01

    Micro-satellite missions, thanks to the miniaturization process of electronic components, now have a broader range of applications. Gauss Group at School of Aerospace Engineering has been a pioneer in educational micro-satellites, namely with UNISAT and EDUSAT missions. Moreover it has been long involved in space debris related studies, such as optical observations as well as mitigation. A new project is under development for a compact digital imaging system. The purpose will be in situ observation of space debris on board Unisat-5 micro-satellite. One of the key elements of observing on orbit is that many atmospheric phenomena would be avoided, such as diffraction and EM absorption. Hence images would gain more contrast and solar spectral irradiance would be higher for the whole visible spectrum Earlier limitations of power and instrument size prevented the inclusion of these payloads in educational satellite missions. The system is composed of an optical tube, a camera, C band and S band transceivers and two antennas. The system is independent from the rest of the spacecraft. The optical tube is a Schmidt-Cassegrain reflector, and the magnitude limit is 13. The camera is equipped with a panchromatic 5Mpix sensor, capable of direct video streaming, as well as local storage of recorded images. The transceivers operate on ISM 2.4GHz and 5 GHz Wi-Fi bands, and they provide stand-alone communication capabilities to the payload, and Unisat-5 OBDH can switch between the two. Both transceivers are connected to their respective custom-designed patch antenna. The ground segment is constituted of a high gain antenna dish, which will use the same transceiver on board the spacecraft as the feed, in order to establish a TCP/IP wireless link. Every component of this system is a consumer grade product. Therefore price reduction of cutting edge imaging technology now allows the use of professional instruments, that combined with the new wireless technology developed for

  13. Space Flight and Re-Entry Trajectories : International Symposium

    CERN Document Server

    Libby, Paul A

    1962-01-01

    In this and a following issue (Vol. VIII, 1962, Fasc. 2-3) of "Astronautica Acta" there will appear the papers presented at the first international symposium sponsored by the International Academy of Astronautics of the International Astronautical Federation. The theme of the meeting was "Space Flight and Re-Entry Trajectories." It was held at Louveciennes outside of Paris on June 19-21, 1961. Sixteen papers by authors from nine countries were presented; attendees numbered from 80 to 100. The organizing committee for the symposium was as follows: Prof. PAUL A. LIBBY, Polytechnic Institute of Brooklyn, U.S.A., Chairman; Prof. LuiGI BROGLIO, University of Rome, Italy; Prof. B. FRAEIJS DE VEUBEKE, University of Liege, Belgium; Dr. D. G. KING-HELE, Royal Aircraft Establishment, Farnborough, Rants, United Kingdom; Prof. J. M. J. KooY, Royal Military School, Breda, Netherlands; Prof. JEAN KovALEVSKY, Bureau des Longitudes, Paris, France; Prof. RuDOLF PESEK, Academy of Sciences, Prague, Czechoslovakia. The detailed ...

  14. Experiments and simulation of a net closing mechanism for tether-net capture of space debris

    Science.gov (United States)

    Sharf, Inna; Thomsen, Benjamin; Botta, Eleonora M.; Misra, Arun K.

    2017-10-01

    This research addresses the design and testing of a debris containment system for use in a tether-net approach to space debris removal. The tether-net active debris removal involves the ejection of a net from a spacecraft by applying impulses to masses on the net, subsequent expansion of the net, the envelopment and capture of the debris target, and the de-orbiting of the debris via a tether to the chaser spacecraft. To ensure a debris removal mission's success, it is important that the debris be successfully captured and then, secured within the net. To this end, we present a concept for a net closing mechanism, which we believe will permit consistently successful debris capture via a simple and unobtrusive design. This net closing system functions by extending the main tether connecting the chaser spacecraft and the net vertex to the perimeter and around the perimeter of the net, allowing the tether to actuate closure of the net in a manner similar to a cinch cord. A particular embodiment of the design in a laboratory test-bed is described: the test-bed itself is comprised of a scaled-down tether-net, a supporting frame and a mock-up debris. Experiments conducted with the facility demonstrate the practicality of the net closing system. A model of the net closure concept has been integrated into the previously developed dynamics simulator of the chaser/tether-net/debris system. Simulations under tether tensioning conditions demonstrate the effectiveness of the closure concept for debris containment, in the gravity-free environment of space, for a realistic debris target. The on-ground experimental test-bed is also used to showcase its utility for validating the dynamics simulation of the net deployment, and a full-scale automated setup would make possible a range of validation studies of other aspects of a tether-net debris capture mission.

  15. Investigations Some Impact Space Debris and Working Satellites

    Science.gov (United States)

    Vovchyk, Yeva

    Combining the coordinate with the photometric date of the artificial satellite the information of its behavior on the orbit, its orientation, form and optical characteristics of the object’s surface could be determined. The successful solution of this task could be received only on the base of complex observations. It means that one must have coordinate and photometric observations from some (at least two) stations and the observations must be done synchronous. Photometric observations enable to record the reflection of the Sunlight from the separate fragments of the object’s surface. The periodic splashes give the information of the own rotation and the precession of the object. But from the light curve of the object to the information of its rotations is a long way of mathematics analysis with the supplement of the information from the other type observations. As the example the way of received the information of the behavior of the two satellites -- “EgyptSat” in the June-August 2010 after its collision on the orbit with unknown space debris and Russian station “Fobos-grunt” in the November 2011 during the unsuccessfully launching, inoperative spacecraft Envisat is shown. In the paper the initial observations and mathematical process of the solution of this task would be given. These investigations were made by the team "Astronoms from Ukraine" -- Ja. Blagodyr, A.Bilinsky, Ye.Vovchyk,K.Martyniyuk-Lotocky from Astronomical Observatory of Ivan Franko National University, Lviv; V.Yepishev, V.Kudak, I.Motrunych,I.Najbaer from Laboratory of the Space Investigations, National University of Uzgorod; N.Koshkin,L. Shakun from Astronomical Observatory of National University of Odessa; V.Lopachenko,V.Rykhalsky from National Centre of Direction and Testing of the Space System, Yevpatoriya.

  16. Research on the new type of multi-functional satellite system for space debris detection

    Science.gov (United States)

    Guo, Linghua; Fu, Qiang; Jiang, Huilin; Xu, Xihe

    2017-05-01

    With the rapid development of space exploration and utilization, orbital debris increases dramatically, leading to great threat to human space activities and spacecraft security. In this paper, a new type of multi-functional space debris satellite system (MSDS) was put forward, which shared main optical system, and possessed functions of multidimensional information detection, polarized remote sensing and high rate transmission. The MSDS system can meet the requirements of detection and identification for the small orbital debris which is 1000km faraway, as well as the requirements of the data transmission by 50 Mbps to 2.5 Gbps@200-1000 km. At the same time, by the method of satellite orbital maneuver and attitude adjusting, the orbital debris information that is real-time, complex and refined, allweather can be acquired and transmitted by the new system. Such new type of multifunctional satellite system can provide important and effective technology for international orbital debris detection.

  17. Yarkovsky-Schach effect on space debris motion

    Science.gov (United States)

    Murawiecka, M.; Lemaitre, A.

    2018-02-01

    The Yarkovsky-Schach effect is a small perturbation affecting Earth satellites and space debris illuminated by the Sun. It was first applied to the orbit of LAGEOS satellites as an explanation of the residuals in orbital elements. In this work, we carry out several numerical integration tests taking into consideration various orbit and rotation parameters, in order to analyse this effect in a broader context. The semi-major axis variations remain small and depend on the spin axis attitude with respect to the Sun. We show that the force amplitude is maximised for orbits inclined with i ≈ 20-30°. We also observe the influence on other orbital elements, notably on the orbit inclination. However, these effects are clearly observed only on long timescales; in our simulations, we propagated the orbits for 200 y. The Yarkovsky-Schach effect is thus confirmed to have a minuscule magnitude. It should be taken into account in studies requiring high-precision orbit determination, or on expanded timescales.

  18. Uncertainty propagation for statistical impact prediction of space debris

    Science.gov (United States)

    Hoogendoorn, R.; Mooij, E.; Geul, J.

    2018-01-01

    Predictions of the impact time and location of space debris in a decaying trajectory are highly influenced by uncertainties. The traditional Monte Carlo (MC) method can be used to perform accurate statistical impact predictions, but requires a large computational effort. A method is investigated that directly propagates a Probability Density Function (PDF) in time, which has the potential to obtain more accurate results with less computational effort. The decaying trajectory of Delta-K rocket stages was used to test the methods using a six degrees-of-freedom state model. The PDF of the state of the body was propagated in time to obtain impact-time distributions. This Direct PDF Propagation (DPP) method results in a multi-dimensional scattered dataset of the PDF of the state, which is highly challenging to process. No accurate results could be obtained, because of the structure of the DPP data and the high dimensionality. Therefore, the DPP method is less suitable for practical uncontrolled entry problems and the traditional MC method remains superior. Additionally, the MC method was used with two improved uncertainty models to obtain impact-time distributions, which were validated using observations of true impacts. For one of the two uncertainty models, statistically more valid impact-time distributions were obtained than in previous research.

  19. Analyzing the capability of a radio telescope in a bistatic space debris observation system

    International Nuclear Information System (INIS)

    Zhao Zhe; Zhao You; Gao Peng-Qi

    2013-01-01

    A bistatic space debris observation system using a radio telescope as the receiving part is introduced. The detection capability of the system at different working frequencies is analyzed based on real instruments. The detection range of targets with a fixed radar cross section and the detection ability of small space debris at a fixed range are discussed. The simulations of this particular observation system at different transmitting powers are also implemented and the detection capability is discussed. The simulated results approximately match the actual experiments. The analysis in this paper provides a theoretical basis for developing a space debris observation system that can be built in China

  20. Proceedings of the Tenth Symposium on Space Nuclear Power and Propulsion

    International Nuclear Information System (INIS)

    El-Genk, M.S.; Hoover, M.D.

    1993-01-01

    This symposium included topics on space nuclear power. Various aspectsof design of propulsion and power systems were presented. From theProceedings, two hundred and twelve papers were abstracted for the database

  1. The 30th AAS Goddard Memorial Symposium. World space programs and fiscal reality: Synopsis

    Science.gov (United States)

    1992-01-01

    A full proceedings of the symposium will be issued later in the year. This synopsis consists of summations of three sessions by appointed rapporteurs. International figures in space and in politics spoke at the sessions. Themes of international cooperation and fiscal reality pervaded the conference. International speakers from Canada, the European Space Agency, Russia, Japan and China and other countries addressed the topic of the symposium. American representation included Senator Barbara Mikulski, former NASA administrator James Beggs and other speakers.

  2. PREFACE: International Symposium on Physical Sciences in Space

    Science.gov (United States)

    Meyer, Andreas; Egry, Ivan

    2011-12-01

    ISPS is the major international scientific forum for researchers in physics utilizing the space environment, in particular microgravity. It is intended to inspire and encourage cross-cutting discussions between different scientific communities working in the same environment. Contributions discussing results of experiments carried out on drop towers, parabolic aircraft flights, sounding rockets, unmanned recoverable capsules and, last but not least, the International Space Station ISS, are the backbone of this conference series, complemented by preparatory ground-based work, both experimentally and theoretically. The first International Symposium on Physical Sciences in Space (ISPS) sponsored by the International Microgravity Strategic Planning Group (IMSPG) took place in 2000 in Sorrento, Italy. IMSPG seeks to coordinate the planning of space for research in physical sciences by space agencies worldwide. AEB (Brazil), ASI (Italy), CNES (France), CSA (Canada), DLR (Germany), ESA (Europe), JAXA (Japan), NASA (USA), NSAU (Ukraine) and RSA (Russia) are members, and CNSA (China) and ISRO (India) are also invited to join IMSPG meetings. ISPS-4 was the fourth symposium in that series, following ISPS-2 organized by CSA in 2004 in Toronto, Canada, and ISPS-3 organized in 2007 by JAXA in Nara, Japan. ISPS-4 was jointly organized by ESA and DLR on behalf of the IMSPG and was held in Bonn from 11-15 July 2011. 230 participants from 17 different countries attended ISPS-4. Recent microgravity experiments were presented, analysed, and set in context to results from Earth bound experiments in 16 plenary and 68 topical talks. Lively discussions continued during two dedicated poster sessions and at the exhibition booths of space industry and research centers with new flight hardware on display. The oral presentations at ISPS4 were selected exclusively on the basis of scientific merit, as evidenced through the submitted abstracts. The selection was performed by the International

  3. Large-size space debris flyby in low earth orbits

    Science.gov (United States)

    Baranov, A. A.; Grishko, D. A.; Razoumny, Y. N.

    2017-09-01

    the analysis of NORAD catalogue of space objects executed with respect to the overall sizes of upper-stages and last stages of carrier rockets allows the classification of 5 groups of large-size space debris (LSSD). These groups are defined according to the proximity of orbital inclinations of the involved objects. The orbits within a group have various values of deviations in the Right Ascension of the Ascending Node (RAAN). It is proposed to use the RAANs deviations' evolution portrait to clarify the orbital planes' relative spatial distribution in a group so that the RAAN deviations should be calculated with respect to the concrete precessing orbital plane of the concrete object. In case of the first three groups (inclinations i = 71°, i = 74°, i = 81°) the straight lines of the RAAN relative deviations almost do not intersect each other. So the simple, successive flyby of group's elements is effective, but the significant value of total Δ V is required to form drift orbits. In case of the fifth group (Sun-synchronous orbits) these straight lines chaotically intersect each other for many times due to the noticeable differences in values of semi-major axes and orbital inclinations. The intersections' existence makes it possible to create such a flyby sequence for LSSD group when the orbit of one LSSD object simultaneously serves as the drift orbit to attain another LSSD object. This flyby scheme requiring less Δ V was called "diagonal." The RAANs deviations' evolution portrait built for the fourth group (to be studied in the paper) contains both types of lines, so the simultaneous combination of diagonal and successive flyby schemes is possible. The value of total Δ V and temporal costs were calculated to cover all the elements of the 4th group. The article is also enriched by the results obtained for the flyby problem solution in case of all the five mentioned LSSD groups. The general recommendations are given concerned with the required reserve of total

  4. Space debris removal using a high-power ground-based laser

    Energy Technology Data Exchange (ETDEWEB)

    Monroe, D.K.

    1993-12-31

    The feasibility and practicality of using a ground-based laser (GBL) to remove artificial space debris is examined. Physical constraints indicate that a reactor-pumped laser (RPL) may be best suited for this mission, because of its capabilities for multimegawatt output long run-times, and near-diffraction-limited initial beams. Simulations of a laser-powered debris removal system indicate that a 5-MW RPL with a 10-meter-diameter beam director and adaptive optics capabilities can deorbit 1-kg debris from space station altitudes. Larger debris can be deorbited or transferred to safer orbits after multiple laser engagements. A ground-based laser system may be the only realistic way to access and remove some 10,000 separate objects, having velocities in the neighborhood of 7 km/sec, and being spatially distributed over some 10{sup 10} km{sup 3} of space.

  5. The Space Debris Crisis: Time for an International Treaty

    Science.gov (United States)

    2011-03-23

    TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Lieutenant Colonel Gregory D. Hillebrand Department of...Military Strategy, Planning, and Operations 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING / MONITORING AGENCY NAME(S) AND...problem is much larger than this. NASA estimates that There are more than 20,000 pieces of debris larger than a softball orbiting the Earth. They

  6. Debris mitigation measures by satellite design and operational methods - Findings from the DLR space debris End-to-End Service

    Science.gov (United States)

    Sdunnus, H.; Beltrami, P.; Janovsky, R.; Koppenwallner, G.; Krag, H.; Reimerdes, H.; Schäfer, F.

    Debris Mitigation has been recognised as an issue to be addressed by the space faring nations around the world. Currently, there are various activities going on, aiming at the establishment of debris mitigation guidelines on various levels, reaching from the UN down to national space agencies. Though guidelines established on the national level already provide concrete information how things should be done (rather that specifying what should be done or providing fundamental principles) potential users of the guidelines will still have the need to explore the technical, management, and financial implications of the guidelines for their projects. Those questions are addressed by the so called "Space Debris End-to-End Service" project, which has been initiated as a national initiative of the German Aerospace Centre (DLR). Based on a review of already existing mitigation guidelines or guidelines under development and following an identification of needs from a circle of industrial users the "End-to-End Service Gu idelines" have been established for designer and operators of spacecraft. The End-to-End Service Guidelines are based on requirements addressed by the mitigation guidelines and provide recommendations how and when the technical consideration of the mitigation guidelines should take place. By referencing requirements from the mitigation guidelines, the End-to-End Service Guidelines address the consideration of debris mitigation measures by spacecraft design and operational measures. This paper will give an introduction to the End-to-End Service Guidelines. It will focus on the proposals made for mitigation measures by the S/C system design, i.e. on protective design measures inside the spacecraft and on design measures, e.g. innovative protective (shielding) systems. Furthermore, approaches on the analytical optimisation of protective systems will be presented, aiming at the minimisation of shield mass under conservation of the protective effects. On the

  7. A deployable mechanism concept for the collection of small-to-medium-size space debris

    Science.gov (United States)

    St-Onge, David; Sharf, Inna; Sagnières, Luc; Gosselin, Clément

    2018-03-01

    Current efforts in active debris removal strategies and mission planning focus on removing the largest, most massive debris. It can be argued, however, that small untrackable debris, specifically those smaller than 5 cm in size, also pose a serious threat. In this work, we propose and analyze a mission to sweep the most crowded Low Earth Orbit with a large cupola device to remove small-to-medium-size debris. The cupola consists of a deployable mechanism expanding more than 25 times its storage size to extend a membrane covering its surface. The membrane is sufficiently stiff to capture most small debris and to slow down the medium-size objects, thus accelerating their fall. An overview of the design of a belt-driven rigid-link mechanism proposed to support the collecting cupola surface is presented, based on our previous work. Because of its large size, the cupola will be subject to significant aerodynamic drag; thus, orbit maintenance analysis is carried out using the DTM-2013 atmospheric density model and it predicts feasible requirements. While in operation, the device will also be subject to numerous hyper-velocity impacts which may significantly perturb its orientation from the desired attitude for debris collection. Thus, another important feature of the proposed debris removal device is a distributed array of flywheels mounted on the cupola for reorienting and stabilizing its attitude during the mission. Analysis using a stochastic modeling framework for hyper-velocity impacts demonstrates that three-axes attitude stabilization is achievable with the flywheels array. MASTER-2009 software is employed to provide relevant data for all debris related estimates, including the debris fluxes for the baseline mission design and for assessment of its expected performance. Space debris removal is a high priority for ensuring sustainability of space and continual launch and operation of man-made space assets. This manuscript presents the first analysis of a small

  8. ROGER a potential orbital space debris removal system

    Science.gov (United States)

    Starke, Juergen; Bischof, Bernd; Foth, W.-O.; -J., J.; Günther

    The previous activities in the field of On Orbit Servicing studied in the 1990's included in partic-ular the capability of vehicles in GEO to capture and support satellites (mainly communication satellites) to enable repair and continuation of operations, and finally the controlled transfer the target into a permanent graveyard orbit. The specific capture tools for these applications were mostly based on robotic systems to capture and fix the target under specific dynamic constraints (e.g. slowly tumbling target) without damage, and to allow the stabilization, re-orientation and potential repair of the target and subsequent release or transport to the final disposal orbit. Due to the drastically increasing number of debris particularly in the Low Earth Orbits (SSO) the active debris removal is now necessary to counteract to the predicted debris production cascade (Kessler Syndrome), which means the pollution of the total sphere in low earth orbit and not only the SSO area. In most of the debris congresses it was recommended to start removal with the still integrated systems as soon as possible. In the case of large debris objects, the soft capture system can be replaced by a simpler and robust system able to operate from a safe distance to the target and flexible enough to capture and hold different types of targets such as deactivated and/or defective satellites, upper stages and big fragments. These nominally non -cooperative targets might be partially destroyed by the capture process, but the production of additional debris shall be avoided. A major argument for the commercial applications is a multi-target mission potential, which is possible at GEO because the transfer propellant requirement to the disposal orbit and the return to the orbit of the next potential target is relative low (orbits with similar inclination and altitude). The proposed ROGER system is designed as a spacecraft with rendezvous capabilities including inspection in the vicinity of the

  9. Charging of Space Debris and Their Dynamical Consequences

    Science.gov (United States)

    2016-01-08

    the Debye screening (λ) length and other typical system lengths of interest such as the object size a [15]. In a collisional plasma i .e. when the...than the Debye lengths and the size of the debris objects. Hence the OML approach can work well in this region and can provide a realistic estimate...mean free path of the ions becomes comparable to the system scale lengths , ion-neutral collisions may lead to the trapping of ions in the sheath region

  10. The bistatic radar capabilities of the Medicina radiotelescopes in space debris detection and tracking

    Science.gov (United States)

    Montebugnoli, S.; Pupillo, G.; Salerno, E.; Pluchino, S.; di Martino, M.

    2010-03-01

    An accurate measurement of the position and trajectory of the space debris fragments is of primary importance for the characterization of the orbital debris environment. The Medicina Radioastronomical Station is a radio observation facility that is here proposed as receiving part of a ground-based space surveillance system for detecting and tracking space debris at different orbital regions (from Low Earth Orbits up to Geostationary Earth Orbits). The proposed system consists of two bistatic radars formed by the existing Medicina receiving antennas coupled with appropriate transmitters. This paper focuses on the current features and future technical development of the receiving part of the observational setup. Outlines of possible transmitting systems will also be given together with the evaluation of the observation strategies achievable with the proposed facilities.

  11. A Numerical Approach to Estimate the Ballistic Coefficient of Space Debris from TLE Orbital Data

    Science.gov (United States)

    Narkeliunas, Jonas

    2016-01-01

    Low Earth Orbit (LEO) is full of space debris, which consist of spent rocket stages, old satellites and fragments from explosions and collisions. As of 2009, more than 21,000 orbital debris larger than 10 cm are known to exist], and while it is hard to track anything smaller than that, the estimated population of particles between 1 and 10 cm in diameter is approximately 500,000, whereas small as 1 cm exceeds 100 million. These objects orbit Earth with huge kinetic energies speeds usually exceed 7 kms. The shape of their orbit varies from almost circular to highly elliptical and covers all LEO, a region in space between 160 and 2,000 km above sea level. Unfortunately, LEO is also the place where most of our active satellites are situated, as well as, International Space Station (ISS) and Hubble Space Telescope, whose orbits are around 400 and 550 km above sea level, respectively.This poses a real threat as debris can collide with satellites and deal substantial damage or even destroy them.Collisions between two or more debris create clouds of smaller debris, which are harder to track and increase overall object density and collision probability. At some point, the debris density couldthen reach a critical value, which would start a chain reaction and the number of space debris would grow exponentially. This phenomenon was first described by Kessler in 1978 and he concluded that it would lead to creation of debris belt, which would vastly complicate satellite operations in LEO. The debris density is already relatively high, as seen from several necessary debris avoidance maneuvers done by Shuttle, before it was discontinued, and ISS. But not all satellites have a propulsion system to avoid collision, hence different methods need to be applied. One of the proposed collision avoidance concepts is called LightForce and it suggests using photon pressure to induce small orbital corrections to deflect debris from colliding. This method is very efficient as seen from

  12. Cost-effective and robust mitigation of space debris in low earth orbit

    Science.gov (United States)

    Walker, R.; Martin, C.

    It is predicted that the space debris population in low Earth orbit (LEO) will continue to grow and in an exponential manner in the long-term due to an increasing rate of collisions between large objects, unless internationally-accepted space debris mitigation measures are adopted soon. Such measures are aimed at avoiding the future generation of space debris objects and primarily need to be effective in preventing significant long-term growth in the debris population, even in the potential scenario of an increase in future space activity. It is also important that mitigation measures can limit future debris population levels, and therefore the underlying collision risk to space missions, to the lowest extent possible. However, for their wide acceptance, the cost of implementation associated with mitigation measures needs to be minimised as far as possible. Generally, a lower collision risk will cost more to achieve and vice versa, so it is necessary to strike a balance between cost and risk in order to find a cost-effective set of mitigation measures. In this paper, clear criteria are established in order to assess the cost-effectiveness of space debris mitigation measures. A full cost-risk-benefit trade-off analysis of numerous mitigation scenarios is presented. These scenarios consider explosion prevention and post-mission disposal of space systems, including de-orbiting to limited lifetime orbits and re-orbiting above the LEO region. The ESA DELTA model is used to provide long-term debris environment projections for these scenarios as input to the benefit and risk parts of the trade-off analysis. Manoeuvre requirements for the different post-mission disposal scenarios were also calculated in order to define the cost-related element. A 25-year post-mission lifetime de-orbit policy, combined with explosion prevention and mission-related object limitation, was found to be the most cost-effective solution to the space debris problem in LEO. This package would also

  13. Exploiting Orbital Data and Observation Campaigns to Improve Space Debris Models

    Science.gov (United States)

    Braun, V.; Horstmann, A.; Reihs, B.; Lemmens, S.; Merz, K.; Krag, H.

    The European Space Agency (ESA) has been developing the Meteoroid and Space Debris Terrestrial Environment Reference (MASTER) software as the European reference model for space debris for more than 25 years. It is an event-based simulation of all known individual debris-generating events since 1957, including breakups, solid rocket motor firings and nuclear reactor core ejections. In 2014, the upgraded Debris Risk Assessment and Mitigation Analysis (DRAMA) tool suite was released. In the same year an ESA instruction made the standard ISO 24113:2011 on space debris mitigation requirements, adopted via the European Cooperation for Space Standardization (ECSS), applicable to all ESA missions. In order to verify the compliance of a space mission with those requirements, the DRAMA software is used to assess collision avoidance statistics, estimate the remaining orbital lifetime and evaluate the on-ground risk for controlled and uncontrolled reentries. In this paper, the approach to validate the MASTER and DRAMA tools is outlined. For objects larger than 1 cm, thus potentially being observable from ground, the MASTER model has been validated through dedicated observation campaigns. Recent campaign results shall be discussed. Moreover, catalogue data from the Space Surveillance Network (SSN) has been used to correlate the larger objects. In DRAMA, the assessment of collision avoidance statistics is based on orbit uncertainty information derived from Conjunction Data Messages (CDM) provided by the Joint Space Operations Center (JSpOC). They were collected for more than 20 ESA spacecraft in the recent years. The way this information is going to be used in a future DRAMA version is outlined and the comparison of estimated manoeuvre rates with real manoeuvres from the operations of ESA spacecraft is shown.

  14. High Precision Optical Observations of Space Debris in the Geo Ring from Venezuela

    Science.gov (United States)

    Lacruz, E.; Abad, C.; Downes, J. J.; Casanova, D.; Tresaco, E.

    2018-01-01

    We present preliminary results to demonstrate that our method for detection and location of Space Debris (SD) in the geostationary Earth orbit (GEO) ring, based on observations at the OAN of Venezuela is of high astrometric precision. A detailed explanation of the method, its validation and first results is available in (Lacruz et al. 2017).

  15. Efficient and automatic image reduction framework for space debris detection based on GPU technology

    Science.gov (United States)

    Diprima, Francesco; Santoni, Fabio; Piergentili, Fabrizio; Fortunato, Vito; Abbattista, Cristoforo; Amoruso, Leonardo

    2018-04-01

    In the last years, the increasing number of space debris has triggered the need of a distributed monitoring system for the prevention of possible space collisions. Space surveillance based on ground telescope allows the monitoring of the traffic of the Resident Space Objects (RSOs) in the Earth orbit. This space debris surveillance has several applications such as orbit prediction and conjunction assessment. In this paper is proposed an optimized and performance-oriented pipeline for sources extraction intended to the automatic detection of space debris in optical data. The detection method is based on the morphological operations and Hough Transform for lines. Near real-time detection is obtained using General Purpose computing on Graphics Processing Units (GPGPU). The high degree of processing parallelism provided by GPGPU allows to split data analysis over thousands of threads in order to process big datasets with a limited computational time. The implementation has been tested on a large and heterogeneous images data set, containing both imaging satellites from different orbit ranges and multiple observation modes (i.e. sidereal and object tracking). These images were taken during an observation campaign performed from the EQUO (EQUatorial Observatory) observatory settled at the Broglio Space Center (BSC) in Kenya, which is part of the ASI-Sapienza Agreement.

  16. Collision risk investigation for an operational spacecraft caused by space debris

    Science.gov (United States)

    Zhang, Binbin; Wang, Zhaokui; Zhang, Yulin

    2017-04-01

    The collision probability between an operational spacecraft and a population of space debris is investigated. By dividing the 3-dimensional operational space of the spacecraft into several space volume cells (SVC) and proposing a boundary selection method to calculate the collision probability in each SVC, the distribution of the collision risk, as functions of the time, the orbital height, the declination, the impact elevation, the collision velocity, etc., can be obtained. Thus, the collision risk could be carefully evaluated over a time span for the general orbital configurations of the spacecraft and the space debris. As an application, the collision risk for the Tiangong-2 space laboratory caused by the cataloged space debris is discussed and evaluated. Results show that most of the collision threat comes from the front left and front right in Tiangong-2's local, quasi-horizontal plane. And the collision probability will also accumulate when Tiangong-2 moves to the largest declinations (about {±} 42°). As a result, the manned space activities should be avoided at those declinations.

  17. Impact of the New Optimal Rules for Arbitration of Disputers Relating to Space Debris Controversies

    Science.gov (United States)

    Force, Melissa K.

    2013-09-01

    The mechanisms and procedures for settlement of disputes arising from space debris collision damage, such as that suffered by the Russian Cosmos and US Iridium satellites in 2009, are highly political, nonbinding and unpredictable - all of which contributes to the uncertainty that increases the costs of financing and insuring those endeavors that take place in near-Earth space, especially in Low Earth Orbit. Dispute settlement mechanisms can be found in the 1967 Outer Space Treaty, which provides for consultations in cases involving potentially harmful interference with activities of States parties, and in the 1972 Liability Convention which permits but does not require States - not non-governmental entities - to pursue claims in a resolution process that is nonbinding (unless otherwise agreed.) There are soft- law mechanisms to control the growth of space debris, such as the voluntary 2008 United Nations Space Debris Mitigation Guidelines, and international law and the principles of equity and justice generally provide reparation to restore a person, State or organization to the condition which would have existed if damage had not occurred, but only if all agree to a specific tribunal or international court; even then, parties may be bound by the result only if agreed and enforcement of the award internationally remains uncertain. In all, the dispute resolution process for damage resulting from inevitable future damage from space debris collisions is highly unsatisfactory. However, the Administrative Council of the Permanent Court of Arbitration's recently adopted Optional Rules for the Arbitration of Disputes Relating to Outer Space Activities are, as of yet, untested, and this article will provide an overview of the process, explore the ways in which they fill in gaps in the previous patchwork of systems and analyze the benefits and shortcomings of the new Outer Space Optional Rules.

  18. The School Bus Symposium: A Poetic Journey of Co-created Conference Space

    Directory of Open Access Journals (Sweden)

    Mitchell A McLarnon

    2016-07-01

    Full Text Available With the intention of disrupting and re-imagining traditional conference spaces, this article is a poetic compilation developed from a Curriculum Studies conference symposium that took place on a school bus. During the School Bus Symposium, in situ poetry writing and reading, song and storytelling occurred in response to open ended prompts and facilitation of creative activities. After the symposium, a call was issued to invite participants to submit any poetry or stories produced during, or inspired by the session. Consisting of 18 submissions including poetry, story, photography and creative essays, infused by curriculum theory and poetic inquiry, this collection offers an inclusive, reflective, participatory, and experiential rendering where participants are living and journeying poetically. Emphasizing creative engagement with personal memories, the authors collectively aimed to promote art education through imaginative approaches to curriculum studies, poetic inquiry and academic conferences.

  19. Hierarchical phase space structure of dark matter haloes: Tidal debris, caustics, and dark matter annihilation

    International Nuclear Information System (INIS)

    Afshordi, Niayesh; Mohayaee, Roya; Bertschinger, Edmund

    2009-01-01

    Most of the mass content of dark matter haloes is expected to be in the form of tidal debris. The density of debris is not constant, but rather can grow due to formation of caustics at the apocenters and pericenters of the orbit, or decay as a result of phase mixing. In the phase space, the debris assemble in a hierarchy that is truncated by the primordial temperature of dark matter. Understanding this phase structure can be of significant importance for the interpretation of many astrophysical observations and, in particular, dark matter detection experiments. With this purpose in mind, we develop a general theoretical framework to describe the hierarchical structure of the phase space of cold dark matter haloes. We do not make any assumption of spherical symmetry and/or smooth and continuous accretion. Instead, working with correlation functions in the action-angle space, we can fully account for the hierarchical structure (predicting a two-point correlation function ∝ΔJ -1.6 in the action space), as well as the primordial discreteness of the phase space. As an application, we estimate the boost to the dark matter annihilation signal due to the structure of the phase space within virial radius: the boost due to the hierarchical tidal debris is of order unity, whereas the primordial discreteness of the phase structure can boost the total annihilation signal by up to an order of magnitude. The latter is dominated by the regions beyond 20% of the virial radius, and is largest for the recently formed haloes with the least degree of phase mixing. Nevertheless, as we argue in a companion paper, the boost due to small gravitationally-bound substructure can dominate this effect at low redshifts.

  20. Hierarchical phase space structure of dark matter haloes: Tidal debris, caustics, and dark matter annihilation

    Science.gov (United States)

    Afshordi, Niayesh; Mohayaee, Roya; Bertschinger, Edmund

    2009-04-01

    Most of the mass content of dark matter haloes is expected to be in the form of tidal debris. The density of debris is not constant, but rather can grow due to formation of caustics at the apocenters and pericenters of the orbit, or decay as a result of phase mixing. In the phase space, the debris assemble in a hierarchy that is truncated by the primordial temperature of dark matter. Understanding this phase structure can be of significant importance for the interpretation of many astrophysical observations and, in particular, dark matter detection experiments. With this purpose in mind, we develop a general theoretical framework to describe the hierarchical structure of the phase space of cold dark matter haloes. We do not make any assumption of spherical symmetry and/or smooth and continuous accretion. Instead, working with correlation functions in the action-angle space, we can fully account for the hierarchical structure (predicting a two-point correlation function ∝ΔJ-1.6 in the action space), as well as the primordial discreteness of the phase space. As an application, we estimate the boost to the dark matter annihilation signal due to the structure of the phase space within virial radius: the boost due to the hierarchical tidal debris is of order unity, whereas the primordial discreteness of the phase structure can boost the total annihilation signal by up to an order of magnitude. The latter is dominated by the regions beyond 20% of the virial radius, and is largest for the recently formed haloes with the least degree of phase mixing. Nevertheless, as we argue in a companion paper, the boost due to small gravitationally-bound substructure can dominate this effect at low redshifts.

  1. Center for Space Transportation and Applied Research Fifth Annual Technical Symposium Proceedings

    Science.gov (United States)

    1993-01-01

    This Fifth Annual Technical Symposium, sponsored by the UT-Calspan Center for Space Transportation and Applied Research (CSTAR), is organized to provide an overview of the technical accomplishments of the Center's five Research and Technology focus areas during the past year. These areas include chemical propulsion, electric propulsion, commerical space transportation, computational methods, and laser materials processing. Papers in the area of artificial intelligence/expert systems are also presented.

  2. Orbital debris: a technical assessment

    National Research Council Canada - National Science Library

    Committee on Space Debris, National Research Council

    ..., and other debris created as a byproduct of space operations. Orbital Debris examines the methods we can use to characterize orbital debris, estimates the magnitude of the debris population, and assesses the hazard that this population poses to spacecraft...

  3. New algorithms for optical observations of space debris with the TAROT telescopes

    Science.gov (United States)

    Laas-Bourez, Myrtille; Boer, Michel; Blanchet, Gwendoline; Ducrotte, Etienne; Klotz, Alain

    To preserve the space environment for the future, and to make space expedition safe, we have to improve our knowledge of the debris population in the vicinity of the geostationary orbit. Since 2004, CNES observes satellites in the geostationary orbit with a network of robotic ground based fully automated telescopes. One is located in France and the second being in ESO La Silla, Chile. This system makes real time processing and its wide field of view is useful for detection, systematic survey and tracking both catalogued and uncatalogued objets. We are implementing new, more efficient, image processing algorithms. A new source extraction algorithm based on morphological mathematic, and a "matching-pursuit" algorithm allow to correlate the measurements of the same object on successive images and give an almost nil false detection rate. These new methods allow us to detect objects on the geostationary belt and on other orbits like MEO or GTO. We also improved the timing precision of individual images (few milliseconds) and the precision of the position restitution respective to the celestial frame. Our "delay card" provides an extremely precise date of objects in a picture and our new algorithm accurately extracts stars from background for calibration; Thanks to all these improvements, the overall efficiency and quality of the survey of the geostationary orbit has drastically improved and we can now detect satellites and debris in different orbits like GTO orbit. In this paper we present our new methods and the work we have made for the detection of space debris: the images dating with a card of delay, the accuracy of astronomical calibration, and the robustness of the extracting space debris with different algorithms. The results obtained on the sky will be shown.

  4. Observations of the orbital debris complex by the Midcourse Space Experiment (MSX) satellite

    Science.gov (United States)

    Vilas, Faith; Anz-Meador, Phillip; Talent, Dave

    1997-01-01

    The midcourse space experiment (MSX) provides the opportunity to observe debris at multiple, simultaneous wavelengths, or in conjunction with other sensors and prior data sets. The instruments onboard MSX include an infrared telescope, an infrared interferometer, a visible telescope, an ultraviolet telescope and a spectroscopic imager. The spacecraft carries calibration spheres for instrument calibration and atmospheric drag studies. The experimental program, the implementation aspects, the data reduction techniques and the preliminary results are described.

  5. Simulation of the space debris environment in LEO using a simplified approach

    Science.gov (United States)

    Kebschull, Christopher; Scheidemann, Philipp; Hesselbach, Sebastian; Radtke, Jonas; Braun, Vitali; Krag, H.; Stoll, Enrico

    2017-01-01

    Several numerical approaches exist to simulate the evolution of the space debris environment. These simulations usually rely on the propagation of a large population of objects in order to determine the collision probability for each object. Explosion and collision events are triggered randomly using a Monte-Carlo (MC) approach. So in many different scenarios different objects are fragmented and contribute to a different version of the space debris environment. The results of the single Monte-Carlo runs therefore represent the whole spectrum of possible evolutions of the space debris environment. For the comparison of different scenarios, in general the average of all MC runs together with its standard deviation is used. This method is computationally very expensive due to the propagation of thousands of objects over long timeframes and the application of the MC method. At the Institute of Space Systems (IRAS) a model capable of describing the evolution of the space debris environment has been developed and implemented. The model is based on source and sink mechanisms, where yearly launches as well as collisions and explosions are considered as sources. The natural decay and post mission disposal measures are the only sink mechanisms. This method reduces the computational costs tremendously. In order to achieve this benefit a few simplifications have been applied. The approach of the model partitions the Low Earth Orbit (LEO) region into altitude shells. Only two kinds of objects are considered, intact bodies and fragments, which are also divided into diameter bins. As an extension to a previously presented model the eccentricity has additionally been taken into account with 67 eccentricity bins. While a set of differential equations has been implemented in a generic manner, the Euler method was chosen to integrate the equations for a given time span. For this paper parameters have been derived so that the model is able to reflect the results of the numerical MC

  6. Modeling and control of a flexible space robot to capture a tumbling debris

    Science.gov (United States)

    Dubanchet, Vincent

    After 60 years of intensive satellite launches, the number of drifting objects in Earth orbits is reaching a shifting point, where human intervention is becoming necessary to reduce the threat of collision. Indeed, a 200 year forecast, known as the "Kessler syndrome", states that space access will be greatly compromised if nothing is done to address the proliferation of these debris. Scientist J.-C. Liou from the National Aeronautics and Space Administration (NASA) has shown that the current trend could be reversed if at least five massive objects, such as dead satellites or rocket upper stages, were de-orbited each year. Among the various technical concepts considered for debris removal, robotics has emerged, over the last 30 years, as one of the most promising solutions. The International Space Station (ISS) already possesses fully operational robotic arms, and other missions have explored the potential of a manipulator embedded onto a satellite. During two of the latter, key capabilities have been demonstrated for on-orbit servicing, and prove to be equally useful for the purpose of debris removal. This thesis focuses on the close range capture of a tumbling debris by a robotic arm with light-weight flexible segments. This phase includes the motion planning and the control of a space robot, in order to smoothly catch a target point on the debris. The validation of such technologies is almost impossible on Earth and leads to prohibitive costs when performed on orbit. Therefore, the modeling and simulation of flexible multi-body systems has been investigated thoroughly, and is likewise a strong contribution of the thesis. Based on these models, an experimental validation is proposed by reproducing the on-orbit kinematics on a test bench made up of two industrial manipulators and driven by a real-time dynamic simulation. In a nutshell, the thesis is built around three main parts: the modeling of a space robot, the design of control laws, and their validation on a

  7. Proceedings of the Twentieth International Symposium on Space Technology and Science. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-31

    The 20th International Symposium on Space Technology and Science was held in Japan on May 19-25, 1996, and a lot of papers were made public. This proceedings has 252 papers of all the papers read in the symposium including the following: Computational fluid dynamics in the design of M-V rocket motors in the propulsion field; Joint structures of carbon-carbon composites in the field of materials and structures; On-orbit attitude control experiment of ETS-VI in the field of astrodynamics, navigation, guidance and control; Magnetic transport of bubbles in liquid in microgravity; The outline and development status of JEM-EF in the field of on-orbit and ground support systems. The proceedings also includes the papers titled Conceptual study of H-IIA rocket in the space transportation field; Microgravity research in the microgravity science field; `Project Genesys` in the field of satellite communications and broadcasting.

  8. Modelling of Structural Loads in Drag Augmented Space Debris Removal Concepts

    DEFF Research Database (Denmark)

    Kristensen, Anders Schmidt; Nikolajsen, Jan Ánike; Lauridsen, Peter Riddersholm

    2017-01-01

    A Self-deployable Deorbiting Space Structure (SDSS) is used for drag augmented space debris removal. A highly flexible frame allows for a folding of the structure by bifurcation. This research models the structural loads during the deployment and unfolding of the drag sail in Low Earth Orbit (LEO......). The Spacecraft travels with 7.8 km/s at deployment. As the drag sail unfolds instantaneously the structure must withstand the loads from the unfolding and the drag. Thermal loads are included in the FEA as the temperature varies from -80°C to +80°C during deorbit. The results are used to verify the structural...

  9. Thrust Control During Towing of Space Debris using an Elastic Tether

    Directory of Open Access Journals (Sweden)

    A. D. Ledkov

    2014-01-01

    Full Text Available The paper considers a maneuver for deorbiting the large space debris using an active spacecraft connected with the debris by an elastic tether. Tether slacking during the maneuver can lead to the tether rupture, kinking, and winding on the descending object. Therefore it is important to prevent slacking. The objective of this work is to find the law of thrust force control of the active spacecraft to ensure a continuously strained tether during the maneuver.Using Lagrange formalism a mathematical model to describe the system plane motion is developed. This model considers the active spacecraft as a mass point, the space debris as a rigid body, and the tether as a weightless elastic rod. A thrust force is directed along the local horizon of the spacecraft. Linearization of nonlinear differential equation describing longitudinal oscillations of the tether length is performed. Its phase portrait is analyzed. An approximate expression describing the position of the center on the phase portrait is obtained. A time-optimal control with full feedback to ensure that the tether is in the strained state is found by solving the Bellman equation. To use the obtained optimal law it is necessary to set the measuring equipment on the spacecraft, which is capable of accurate measuring a distance to the space debris and its relative velocity. An alternative control law, which is simpler in terms of the practical implementation, is proposed. As an example, the descent from an orbit of nonfunctioning Soviet satellite Meteor-2 is considered. It is shown that both proposed laws provide continuous strain of the tether during deorbiting of the satellite. Moreover, slack does not occur even at the first period of oscillation of the tether length. It is shown that the use of the proposed control laws leads to slight increase of deorbiting time as compared to the case of using the constant thrust.The results can be used to develop the control systems of small spacecrafts

  10. 8th symposium on space nuclear power systems

    International Nuclear Information System (INIS)

    Brandhorst, H. W.

    1991-01-01

    The future appears rich in missions that will extend the frontiers of knowledge, human presence in space, and opportunities for profitable commerce. Key to the success of these ventures is the availability of plentiful, cost effective electric power and assured, low cost access to space. While forecasts of space power needs are problematic, an assessment of future needs based on terrestrial experience has been made. These needs fall into three broad categories: survival, self sufficiency, and industrialization. The cost of delivering payloads to orbital locations from LEO to Mars has been determined and future launch cost reductions projected. From these factors, then, projections of the performance necessary for future solar and nuclear space power options has been made. These goals are largely dependent upon orbital location and energy storage needs. Finally the cost of present space power systems has been determined and projections made for future systems

  11. Implementation of an Open-Scenario, Long-Term Space Debris Simulation Approach

    Science.gov (United States)

    Nelson, Bron; Yang Yang, Fan; Carlino, Roberto; Dono Perez, Andres; Faber, Nicolas; Henze, Chris; Karacalioglu, Arif Goktug; O'Toole, Conor; Swenson, Jason; Stupl, Jan

    2015-01-01

    This paper provides a status update on the implementation of a flexible, long-term space debris simulation approach. The motivation is to build a tool that can assess the long-term impact of various options for debris-remediation, including the LightForce space debris collision avoidance concept that diverts objects using photon pressure [9]. State-of-the-art simulation approaches that assess the long-term development of the debris environment use either completely statistical approaches, or they rely on large time steps on the order of several days if they simulate the positions of single objects over time. They cannot be easily adapted to investigate the impact of specific collision avoidance schemes or de-orbit schemes, because the efficiency of a collision avoidance maneuver can depend on various input parameters, including ground station positions and orbital and physical parameters of the objects involved in close encounters (conjunctions). Furthermore, maneuvers take place on timescales much smaller than days. For example, LightForce only changes the orbit of a certain object (aiming to reduce the probability of collision), but it does not remove entire objects or groups of objects. In the same sense, it is also not straightforward to compare specific de-orbit methods in regard to potential collision risks during a de-orbit maneuver. To gain flexibility in assessing interactions with objects, we implement a simulation that includes every tracked space object in Low Earth Orbit (LEO) and propagates all objects with high precision and variable time-steps as small as one second. It allows the assessment of the (potential) impact of physical or orbital changes to any object. The final goal is to employ a Monte Carlo approach to assess the debris evolution during the simulation time-frame of 100 years and to compare a baseline scenario to debris remediation scenarios or other scenarios of interest. To populate the initial simulation, we use the entire space

  12. Third International Symposium on Artificial Intelligence, Robotics, and Automation for Space 1994

    Science.gov (United States)

    1994-01-01

    The Third International Symposium on Artificial Intelligence, Robotics, and Automation for Space (i-SAIRAS 94), held October 18-20, 1994, in Pasadena, California, was jointly sponsored by NASA, ESA, and Japan's National Space Development Agency, and was hosted by the Jet Propulsion Laboratory (JPL) of the California Institute of Technology. i-SAIRAS 94 featured presentations covering a variety of technical and programmatic topics, ranging from underlying basic technology to specific applications of artificial intelligence and robotics to space missions. i-SAIRAS 94 featured a special workshop on planning and scheduling and provided scientists, engineers, and managers with the opportunity to exchange theoretical ideas, practical results, and program plans in such areas as space mission control, space vehicle processing, data analysis, autonomous spacecraft, space robots and rovers, satellite servicing, and intelligent instruments.

  13. Development of the KARI Space Debris Collision Risk Management System (KARISMA)

    Science.gov (United States)

    Kim, Hae-Dong; Lee, Sang-Cherl; Cho, Dong-Hyun; Seong, Jae-Dong

    2018-05-01

    Korea has been operating multi-purpose low-earth orbit (LEO) satellites such as the Korea multi-purpose satellite (KOMPSAT) since 1999 and the Communication, Ocean, and Meteorological Satellite (COMS), which was launched into geostationary orbit in 2006. The Korea Aerospace Research Institute (KARI) consequently became concerned about the deteriorating space debris environment. This led to the instigation, in 2011, of a project to develop the KARI space debris collision risk management system (KARISMA). In 2014, KARISMA was adopted as an official tool at the KARI ground station and is operated to mitigate collision risks while being continuously upgraded with input from satellite operators. The characteristics and architecture of KARISMA are described with detailed operational views. The user-friendly user interfaces including 2D and 3D displays of the results, conjunction geometries, and so on, are described in detail. The results of our analysis of the space collision risk faced by the KOMPSAT satellites as determined using KARISMA are presented, as well as optimized collision avoidance maneuver planning with maneuvering strategies for several conjunction events. Consequently, the development of KARISMA to provide detailed descriptions is expected to contribute significantly to satellite operators and owners who require tools with many useful functions to mitigate collision risk.

  14. Validated simulator for space debris removal with nets and other flexible tethers applications

    Science.gov (United States)

    Gołębiowski, Wojciech; Michalczyk, Rafał; Dyrek, Michał; Battista, Umberto; Wormnes, Kjetil

    2016-12-01

    In the context of active debris removal technologies and preparation activities for the e.Deorbit mission, a simulator for net-shaped elastic bodies dynamics and their interactions with rigid bodies, has been developed. Its main application is to aid net design and test scenarios for space debris deorbitation. The simulator can model all the phases of the debris capturing process: net launch, flight and wrapping around the target. It handles coupled simulation of rigid and flexible bodies dynamics. Flexible bodies were implemented using Cosserat rods model. It allows to simulate flexible threads or wires with elasticity and damping for stretching, bending and torsion. Threads may be combined into structures of any topology, so the software is able to simulate nets, pure tethers, tether bundles, cages, trusses, etc. Full contact dynamics was implemented. Programmatic interaction with simulation is possible - i.e. for control implementation. The underlying model has been experimentally validated and due to significant gravity influence, experiment had to be performed in microgravity conditions. Validation experiment for parabolic flight was a downscaled process of Envisat capturing. The prepacked net was launched towards the satellite model, it expanded, hit the model and wrapped around it. The whole process was recorded with 2 fast stereographic camera sets for full 3D trajectory reconstruction. The trajectories were used to compare net dynamics to respective simulations and then to validate the simulation tool. The experiments were performed on board of a Falcon-20 aircraft, operated by National Research Council in Ottawa, Canada. Validation results show that model reflects phenomenon physics accurately enough, so it may be used for scenario evaluation and mission design purposes. The functionalities of the simulator are described in detail in the paper, as well as its underlying model, sample cases and methodology behind validation. Results are presented and

  15. Space and the Third Offset Symposium - Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Bahney, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-01-05

    The Third Offset Workshop explored the nature of the challenges and opportunities facing the United States as it is increasingly forced to integrate space into defense strategy as well as deterrence and strategic stability frameworks. Participants broadly agreed that Washington’s deep ties to allies and partners, as well as its history of leveraging an innovative U.S private sector, will be enduring competitive advantages against potential rivals into the foreseeable future. Yet panelists also highlighted key challenges from Russia and China’s rapid integration of space capabilities into conventional and nuclear warfighting, the pronounced growth in Chinese and Russian counterspace capabilities, and tensions in the U.S.-Russia relationship.

  16. StreakDet data processing and analysis pipeline for space debris optical observations

    Science.gov (United States)

    Virtanen, Jenni; Flohrer, Tim; Muinonen, Karri; Granvik, Mikael; Torppa, Johanna; Poikonen, Jonne; Lehti, Jussi; Santti, Tero; Komulainen, Tuomo; Naranen, Jyri

    We describe a novel data processing and analysis pipeline for optical observations of space debris. The monitoring of space object populations requires reliable acquisition of observational data, to support the development and validation of space debris environment models, the build-up and maintenance of a catalogue of orbital elements. In addition, data is needed for the assessment of conjunction events and for the support of contingency situations or launches. The currently available, mature image processing algorithms for detection and astrometric reduction of optical data cover objects that cross the sensor field-of-view comparably slowly, and within a rather narrow, predefined range of angular velocities. By applying specific tracking techniques, the objects appear point-like or as short trails in the exposures. However, the general survey scenario is always a “track before detect” problem, resulting in streaks, i.e., object trails of arbitrary lengths, in the images. The scope of the ESA-funded StreakDet (Streak detection and astrometric reduction) project is to investigate solutions for detecting and reducing streaks from optical images, particularly in the low signal-to-noise ratio (SNR) domain, where algorithms are not readily available yet. For long streaks, the challenge is to extract precise position information and related registered epochs with sufficient precision. Although some considerations for low-SNR processing of streak-like features are available in the current image processing and computer vision literature, there is a need to discuss and compare these approaches for space debris analysis, in order to develop and evaluate prototype implementations. In the StreakDet project, we develop algorithms applicable to single images (as compared to consecutive frames of the same field) obtained with any observing scenario, including space-based surveys and both low- and high-altitude populations. The proposed processing pipeline starts from the

  17. Active space debris removal—A preliminary mission analysis and design

    Science.gov (United States)

    Castronuovo, Marco M.

    2011-11-01

    The active removal of five to ten large objects per year from the low Earth orbit (LEO) region is the only way to prevent the debris collisions from cascading. Among the three orbital regions near the Earth where most catastrophic collisions are predicted to occur, the one corresponding to a sun-synchronous condition is considered the most relevant. Forty-one large rocket bodies orbiting in this belt have been identified as the priority targets for removal. As part of a more comprehensive system engineering solution, a space mission dedicated to the de-orbiting of five rocket bodies per year from this orbital regime has been designed. The selected concept of operations envisages the launch of a satellite carrying a number of de-orbiting devices, such as solid propellant kits. The satellite performs a rendezvous with an identified object and mates with it by means of a robotic arm. A de-orbiting device is attached to the object by means of a second robotic arm, the object is released and the device is activated. The spacecraft travels then to the next target. The present paper shows that an active debris removal mission capable of de-orbiting 35 large objects in 7 years is technically feasible, and the resulting propellant mass budget is compatible with many existing platforms.

  18. A 1 cm space debris impact onto the Sentinel-1A solar array

    Science.gov (United States)

    Krag, H.; Serrano, M.; Braun, V.; Kuchynka, P.; Catania, M.; Siminski, J.; Schimmerohn, M.; Marc, X.; Kuijper, D.; Shurmer, I.; O'Connell, A.; Otten, M.; Muñoz, Isidro; Morales, J.; Wermuth, M.; McKissock, D.

    2017-08-01

    Sentinel-1A is a 2-ton spacecraft of the Copernicus Earth observation program operated by ESA's Space Operations Centre in Darmstadt, Germany. Sentinel-1A and its sister spacecraft Sentinel-1B operate in a sun-synchronous orbit at about 700 km altitude. On 2016/08/23 17:07:37 UTC, Sentinel-1A suffered from an anomaly resulting in a sudden permanent partial power loss and significant impulsive orbit and attitude changes. A deeper investigation identified that an impulsive orbit change against flight direction of 0.7 mm/s, estimated at the time of the event, gave the best results in terms of GPS residuals. At the same time, a peak attitude off-pointing of 0.7° (around the spacecraft yaw axis) and peak attitude rate increase of 0.04°/s (around the same axis) were observed. The simultaneous occurrence of these anomalies, starting from a sudden attitude change and ending with a permanent partial power loss, made an MMOD (Micro-Meteoroid and Orbital Debris) impact onto a solar array a possible explanation for this event. While the spacecraft is able to continue its mission nominally, a detailed investigation involving ESA's Space Debris and Flight Dynamics experts was conducted. An MMOD impact as an explanation gained further credibility, due to the pictures of the solar array taken by the on-board camera displaying a significant damage area. On September 7th, JSpOC (US Joint Space Operations Centre) informed SDO on 8 tracked fragments that are considered to be released by Sentinel-1A after the impact. This paper addresses the analysis that was performed on the data characterising the attitude and orbit change, the on-board camera image, and the tracked fragments. The data helped to identify the linear momentum vector while a flux analysis helped to identify the origin of the impactor and allowed to understand its mass and size characteristics.

  19. Photon Pressure Force on Space Debris TOPEX/Poseidon Measured by Satellite Laser Ranging

    Science.gov (United States)

    Kucharski, D.; Kirchner, G.; Bennett, J. C.; Lachut, M.; Sośnica, K.; Koshkin, N.; Shakun, L.; Koidl, F.; Steindorfer, M.; Wang, P.; Fan, C.; Han, X.; Grunwaldt, L.; Wilkinson, M.; Rodríguez, J.; Bianco, G.; Vespe, F.; Catalán, M.; Salmins, K.; del Pino, J. R.; Lim, H.-C.; Park, E.; Moore, C.; Lejba, P.; Suchodolski, T.

    2017-10-01

    The (TOPography EXperiment) TOPEX/Poseidon (T/P) altimetry mission operated for 13 years before the satellite was decommissioned in January 2006, becoming a large space debris object at an altitude of 1,340 km. Since the end of the mission, the interaction of T/P with the space environment has driven the satellite's spin dynamics. Satellite laser ranging (SLR) measurements collected from June 2014 to October 2016 allow for the satellite spin axis orientation to be determined with an accuracy of 1.7°. The spin axis coincides with the platform yaw axis (formerly pointing in the nadir direction) about which the body rotates in a counterclockwise direction. The combined photometric and SLR data collected over the 11 year time span indicates that T/P has continuously gained rotational energy at an average rate of 2.87 J/d and spins with a period of 10.73 s as of 19 October 2016. The satellite attitude model shows a variation of the cross-sectional area in the Sun direction between 8.2 m2 and 34 m2. The direct solar radiation pressure is the main factor responsible for the spin-up of the body, and the exerted photon force varies from 65 μN to 228 μN around the mean value of 138.6 μN. Including realistic surface force modeling in orbit propagation algorithms will improve the prediction accuracy, giving better conjunction warnings for scenarios like the recent close approach reported by the ILRS Space Debris Study Group—an approximate 400 m flyby between T/P and Jason-2 on 20 June 2017.

  20. Impact interaction of shells and structural elements of spacecrafts with the particles of space debris and micrometeoroids

    Science.gov (United States)

    Gerasimov, A. V.; Pashkov, S. V.; Khristenko, Yu. F.

    2017-10-01

    Space debris formed during the launch and operation of spacecrafts in the circumterrestrial space, and the flows of micrometeoroids from the depths of space pose a real threat to manned and automatic vehicles. Providing the fracture resistance of aluminum, glass and ceramic spacecraft elements is an important practical task. These materials are widely used in spacecraft elements such as bodies, tanks, windows, glass in optical devices, heat shields, etc.

  1. LightForce Photon-Pressure Collision Avoidance: Efficiency Assessment on an Entire Catalogue of Space Debris

    Science.gov (United States)

    Stupl, Jan Michael; Faber, Nicolas; Foster, Cyrus; Yang Yang, Fan; Levit, Creon

    2013-01-01

    The potential to perturb debris orbits using photon pressure from ground-based lasers has been confirmed by independent research teams. Two useful applications of this scheme are protecting space assets from impacts with debris and stabilizing the orbital debris environment, both relying on collision avoidance rather than de-orbiting debris. This paper presents the results of a new assessment method to analyze the efficiency of the concept for collision avoidance. Earlier research concluded that one ground based system consisting of a 10 kW class laser, directed by a 1.5 m telescope with adaptive optics, can prevent a significant fraction of debris-debris collisions in low Earth orbit. That research used in-track displacement to measure efficiency and restricted itself to an analysis of a limited number of objects. As orbit prediction error is dependent on debris object properties, a static displacement threshold should be complemented with another measure to assess the efficiency of the scheme. In this paper we present the results of an approach using probability of collision. Using a least-squares fitting method, we improve the quality of the original TLE catalogue in terms of state and co-state accuracy. We then calculate collision probabilities for all the objects in the catalogue. The conjunctions with the highest risk of collision are then engaged by a simulated network of laser ground stations. After those engagements, the perturbed orbits are used to re-assess the collision probability in a 20 minute window around the original conjunction. We then use different criteria to evaluate the utility of the laser-based collision avoidance scheme and assess the number of base-line ground stations needed to mitigate a significant number of high probability conjunctions. Finally, we also give an account how a laser ground station can be used for both orbit deflection and debris tracking.

  2. Implementation of National Space Policy on US Air Force End of Life Operations and Orbital Debris Mitigation

    Science.gov (United States)

    2012-06-01

    Space Development and Test Directorate, Kirtland AFB, NM, 87117 Recent changes to US space policy regarding the execution of satellite End of Life ( EOL ...procedures have been driven by the rising significance of the orbital debris problem in Low Earth Orbit (LEO). Therefore current EOL plans are...considerations for writing operational EOL plans, with special applicability to military missions and focus on LEO satellites that are unable to relocate

  3. Operational support to collision avoidance activities by ESA's space debris office

    Science.gov (United States)

    Braun, V.; Flohrer, T.; Krag, H.; Merz, K.; Lemmens, S.; Bastida Virgili, B.; Funke, Q.

    2016-09-01

    The European Space Agency's (ESA) Space Debris Office provides a service to support operational collision avoidance activities. This support currently covers ESA's missions Cryosat-2, Sentinel-1A and -2A, the constellation of Swarm-A/B/C in low-Earth orbit (LEO), as well as missions of third-party customers. In this work, we describe the current collision avoidance process for ESA and third-party missions in LEO. We give an overview on the upgrades developed and implemented since the advent of conjunction summary messages (CSM)/conjunction data messages (CDM), addressing conjunction event detection, collision risk assessment, orbit determination, orbit and covariance propagation, process control, and data handling. We pay special attention to the effect of warning thresholds on the risk reduction and manoeuvre rates, as they are established through risk mitigation and analysis tools, such as ESA's Debris Risk Assessment and Mitigation Analysis (DRAMA) software suite. To handle the large number of CDMs and the associated risk analyses, a database-centric approach has been developed. All CDMs and risk analysis results are stored in a database. In this way, a temporary local "mini-catalogue" of objects close to our target spacecraft is obtained, which can be used, e.g., for manoeuvre screening and to update the risk analysis whenever a new ephemeris becomes available from the flight dynamics team. The database is also used as the backbone for a Web-based tool, which consists of the visualization component and a collaboration tool that facilitates the status monitoring and task allocation within the support team as well as communication with the control team. The visualization component further supports the information sharing by displaying target and chaser motion over time along with the involved uncertainties. The Web-based solution optimally meets the needs for a concise and easy-to-use way to obtain a situation picture in a very short time, and the support for

  4. Proceedings of The Twentieth International Symposium on Space Technology and Science. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-31

    The 20th international symposium on space technology and science was held in Nagaragawa city, Gifu prefecture on May 19-25, 1996, and 401 papers were made public. Out of those, 112 papers were summed up as Volume 2 following the previous Volume 1. As to space transportation, the paper included reports titled as follows: Conceptual study of H-IIA rocket (upgraded H-II rocket); Test flight of the launch vehicle; International cooperation in space transportation; etc. Concerning microgravity science, Recent advances in microgravity research; Use of microgravity environment to investigate the effect of magnetic field on flame shape; etc. Relating to satellite communications and broadcasting, `Project GENESYS`: CRL`s R and D project for realizing high data rate satellite communications networks; The Astrolink {sup TM/SM} system; etc. Besides, the paper contained reports on the following fields: lunar and planetary missions and utilization, space science and balloons, earth observations, life science and human presence, international cooperation and space environment, etc

  5. Streak detection and analysis pipeline for space-debris optical images

    Science.gov (United States)

    Virtanen, Jenni; Poikonen, Jonne; Säntti, Tero; Komulainen, Tuomo; Torppa, Johanna; Granvik, Mikael; Muinonen, Karri; Pentikäinen, Hanna; Martikainen, Julia; Näränen, Jyri; Lehti, Jussi; Flohrer, Tim

    2016-04-01

    We describe a novel data-processing and analysis pipeline for optical observations of moving objects, either of natural (asteroids, meteors) or artificial origin (satellites, space debris). The monitoring of the space object populations requires reliable acquisition of observational data, to support the development and validation of population models and to build and maintain catalogues of orbital elements. The orbital catalogues are, in turn, needed for the assessment of close approaches (for asteroids, with the Earth; for satellites, with each other) and for the support of contingency situations or launches. For both types of populations, there is also increasing interest to detect fainter objects corresponding to the small end of the size distribution. The ESA-funded StreakDet (streak detection and astrometric reduction) activity has aimed at formulating and discussing suitable approaches for the detection and astrometric reduction of object trails, or streaks, in optical observations. Our two main focuses are objects in lower altitudes and space-based observations (i.e., high angular velocities), resulting in long (potentially curved) and faint streaks in the optical images. In particular, we concentrate on single-image (as compared to consecutive frames of the same field) and low-SNR detection of objects. Particular attention has been paid to the process of extraction of all necessary information from one image (segmentation), and subsequently, to efficient reduction of the extracted data (classification). We have developed an automated streak detection and processing pipeline and demonstrated its performance with an extensive database of semisynthetic images simulating streak observations both from ground-based and space-based observing platforms. The average processing time per image is about 13 s for a typical 2k-by-2k image. For long streaks (length >100 pixels), primary targets of the pipeline, the detection sensitivity (true positives) is about 90% for

  6. Analysis of Approaches to the Near-Earth Orbit Cleanup from Space Debris of the Size Below10 cm

    Directory of Open Access Journals (Sweden)

    V. I. Maiorova

    2016-01-01

    Full Text Available Nowadays, there are a lot of concepts aimed at space debris removal from the near-Earth orbits being under way at different stages of detailed engineering and design. As opposed to large-size space debris (upper-stages, rocket bodies, non-active satellites, to track the small objects of space debris (SOSD, such as picosatellites, satellite fragments, pyrotechnic devices, and other items less than 10 cm in size, using the ground stations is, presently, a challenge.This SOSD feature allows the authors to propose the two most rational approaches, which use, respectively, a passive and an active (prompt maneuverable space vehicles (SV and appropriate schematic diagrams for their collection:1 Passive scheme – space vehicle (SV to be launched into an orbit is characterized by high mathematical expectation of collision with a large amount of SOSD and, accordingly, by high probability to be captured using both active or the passive tools. The SV does not execute any maneuvers, but can be equipped with a propulsion system required for orbit’s maintenance and correction and also for solving the tasks of long-range guidance.2 Active scheme – the SV is to be launched into the target or operating orbit and executes a number of maneuvers to capture the SOSD using both active and passive tools. Thus, such a SV has to be equipped with a rather high-trust propulsion system, which allows the change of its trajectory and also with the guidance system to provide it with target coordinates. The guidance system can be built on either radio or optical devices, it can be installed onboard the debris-removal SV or onboard the SV which operates as a supply unit (if such SVs are foreseen.The paper describes each approach, emphasizes advantages and disadvantages, and defines the cutting-edge technologies to be implemented.

  7. ON THE DETECTION AND TRACKING OF SPACE DEBRIS USING THE MURCHISON WIDEFIELD ARRAY. I. SIMULATIONS AND TEST OBSERVATIONS DEMONSTRATE FEASIBILITY

    Energy Technology Data Exchange (ETDEWEB)

    Tingay, S. J.; Wayth, R. B.; Hurley-Walker, N.; Kennewell, J.; Arcus, W.; Bhat, N. D. R.; Emrich, D.; Herne, D.; Kudryavtseva, N.; Lynch, M.; Ord, S. M.; Waterson, M. [International Centre for Radio Astronomy Research, Curtin University, Perth (Australia); Kaplan, D. L. [University of Wisconsin-Milwaukee, Milwaukee (United States); McKinley, B.; Briggs, F.; Bell, M.; Gaensler, B. M. [ARC Centre of Excellence for All-sky Astrophysics (CAASTRO), Sydney (Australia); Smith, C. [Electro Optic Systems Pty Ltd, Canberra (Australia); Zhang, K. [RMIT University, Melbourne (Australia); Barnes, D. G., E-mail: s.tingay@curtin.edu.au [Monash e-Research Centre, Monash University, Clayton (Australia); and others

    2013-10-01

    The Murchison Widefield Array (MWA) is a new low-frequency interferometric radio telescope, operating in the benign radio frequency environment of remote Western Australia. The MWA is the low-frequency precursor to the Square Kilometre Array (SKA) and is the first of three SKA precursors to be operational, supporting a varied science mission ranging from the attempted detection of the Epoch of Reionization to the monitoring of solar flares and space weather. In this paper we explore the possibility that the MWA can be used for the purposes of Space Situational Awareness (SSA). In particular we propose that the MWA can be used as an element of a passive radar facility operating in the frequency range 87.5-108 MHz (the commercial FM broadcast band). In this scenario the MWA can be considered the receiving element in a bi-static radar configuration, with FM broadcast stations serving as non-cooperative transmitters. The FM broadcasts propagate into space, are reflected off debris in Earth orbit, and are received at the MWA. The imaging capabilities of the MWA can be used to simultaneously detect multiple pieces of space debris, image their positions on the sky as a function of time, and provide tracking data that can be used to determine orbital parameters. Such a capability would be a valuable addition to Australian and global SSA assets, in terms of southern and eastern hemispheric coverage. We provide a feasibility assessment of this proposal, based on simple calculations and electromagnetic simulations, that shows that the detection of sub-meter size debris should be possible (debris radius of >0.5 m to ∼1000 km altitude). We also present a proof-of-concept set of observations that demonstrate the feasibility of the proposal, based on the detection and tracking of the International Space Station via reflected FM broadcast signals originating in southwest Western Australia. These observations broadly validate our calculations and simulations. We discuss some

  8. On the Detection and Tracking of Space Debris Using the Murchison Widefield Array. I. Simulations and Test Observations Demonstrate Feasibility

    Science.gov (United States)

    Tingay, S. J.; Kaplan, D. L.; McKinley, B.; Briggs, F.; Wayth, R. B.; Hurley-Walker, N.; Kennewell, J.; Smith, C.; Zhang, K.; Arcus, W.; Bhat, N. D. R.; Emrich, D.; Herne, D.; Kudryavtseva, N.; Lynch, M.; Ord, S. M.; Waterson, M.; Barnes, D. G.; Bell, M.; Gaensler, B. M.; Lenc, E.; Bernardi, G.; Greenhill, L. J.; Kasper, J. C.; Bowman, J. D.; Jacobs, D.; Bunton, J. D.; deSouza, L.; Koenig, R.; Pathikulangara, J.; Stevens, J.; Cappallo, R. J.; Corey, B. E.; Kincaid, B. B.; Kratzenberg, E.; Lonsdale, C. J.; McWhirter, S. R.; Rogers, A. E. E.; Salah, J. E.; Whitney, A. R.; Deshpande, A.; Prabu, T.; Udaya Shankar, N.; Srivani, K. S.; Subrahmanyan, R.; Ewall-Wice, A.; Feng, L.; Goeke, R.; Morgan, E.; Remillard, R. A.; Williams, C. L.; Hazelton, B. J.; Morales, M. F.; Johnston-Hollitt, M.; Mitchell, D. A.; Procopio, P.; Riding, J.; Webster, R. L.; Wyithe, J. S. B.; Oberoi, D.; Roshi, A.; Sault, R. J.; Williams, A.

    2013-10-01

    The Murchison Widefield Array (MWA) is a new low-frequency interferometric radio telescope, operating in the benign radio frequency environment of remote Western Australia. The MWA is the low-frequency precursor to the Square Kilometre Array (SKA) and is the first of three SKA precursors to be operational, supporting a varied science mission ranging from the attempted detection of the Epoch of Reionization to the monitoring of solar flares and space weather. In this paper we explore the possibility that the MWA can be used for the purposes of Space Situational Awareness (SSA). In particular we propose that the MWA can be used as an element of a passive radar facility operating in the frequency range 87.5-108 MHz (the commercial FM broadcast band). In this scenario the MWA can be considered the receiving element in a bi-static radar configuration, with FM broadcast stations serving as non-cooperative transmitters. The FM broadcasts propagate into space, are reflected off debris in Earth orbit, and are received at the MWA. The imaging capabilities of the MWA can be used to simultaneously detect multiple pieces of space debris, image their positions on the sky as a function of time, and provide tracking data that can be used to determine orbital parameters. Such a capability would be a valuable addition to Australian and global SSA assets, in terms of southern and eastern hemispheric coverage. We provide a feasibility assessment of this proposal, based on simple calculations and electromagnetic simulations, that shows that the detection of sub-meter size debris should be possible (debris radius of >0.5 m to ~1000 km altitude). We also present a proof-of-concept set of observations that demonstrate the feasibility of the proposal, based on the detection and tracking of the International Space Station via reflected FM broadcast signals originating in southwest Western Australia. These observations broadly validate our calculations and simulations. We discuss some

  9. ON THE DETECTION AND TRACKING OF SPACE DEBRIS USING THE MURCHISON WIDEFIELD ARRAY. I. SIMULATIONS AND TEST OBSERVATIONS DEMONSTRATE FEASIBILITY

    International Nuclear Information System (INIS)

    Tingay, S. J.; Wayth, R. B.; Hurley-Walker, N.; Kennewell, J.; Arcus, W.; Bhat, N. D. R.; Emrich, D.; Herne, D.; Kudryavtseva, N.; Lynch, M.; Ord, S. M.; Waterson, M.; Kaplan, D. L.; McKinley, B.; Briggs, F.; Bell, M.; Gaensler, B. M.; Smith, C.; Zhang, K.; Barnes, D. G.

    2013-01-01

    The Murchison Widefield Array (MWA) is a new low-frequency interferometric radio telescope, operating in the benign radio frequency environment of remote Western Australia. The MWA is the low-frequency precursor to the Square Kilometre Array (SKA) and is the first of three SKA precursors to be operational, supporting a varied science mission ranging from the attempted detection of the Epoch of Reionization to the monitoring of solar flares and space weather. In this paper we explore the possibility that the MWA can be used for the purposes of Space Situational Awareness (SSA). In particular we propose that the MWA can be used as an element of a passive radar facility operating in the frequency range 87.5-108 MHz (the commercial FM broadcast band). In this scenario the MWA can be considered the receiving element in a bi-static radar configuration, with FM broadcast stations serving as non-cooperative transmitters. The FM broadcasts propagate into space, are reflected off debris in Earth orbit, and are received at the MWA. The imaging capabilities of the MWA can be used to simultaneously detect multiple pieces of space debris, image their positions on the sky as a function of time, and provide tracking data that can be used to determine orbital parameters. Such a capability would be a valuable addition to Australian and global SSA assets, in terms of southern and eastern hemispheric coverage. We provide a feasibility assessment of this proposal, based on simple calculations and electromagnetic simulations, that shows that the detection of sub-meter size debris should be possible (debris radius of >0.5 m to ∼1000 km altitude). We also present a proof-of-concept set of observations that demonstrate the feasibility of the proposal, based on the detection and tracking of the International Space Station via reflected FM broadcast signals originating in southwest Western Australia. These observations broadly validate our calculations and simulations. We discuss some

  10. A SPH Method-based Numerical Simulation of the Space Debris Fragments Interaction with Spacecraft Structure Components

    Directory of Open Access Journals (Sweden)

    V. V. Zelentsov

    2017-01-01

    Full Text Available Significant amount of space debris available in the near-Earth space is a reason to protect space vehicles from the fragments of space debris. Existing empirical calculation methods do not allow us to estimate quality of developed protection. Experimental verification of protection requires complex and expensive installations that do not allow having a desirable impact velocity. The article proposes to use the ANSYS AUTODYN software environment – a software complex of the nonlinear dynamic analysis to evaluate quality of developed protection. The ANSYS AUTODYN environment is based on the integration methods of a system of equations of continuum mechanics. The SPH (smoothed particle method method is used as a solver. The SPH method is based on the area of sampling by a finite set of the Lagrangian particles that can be represented as the elementary volumes of the medium. In modeling the targets were under attack of 2 and 3 mm spheres and cylinders with 2 mm in bottom diameter and with generator of 2 and 3 mm. The apheres and cylinders are solid and hollow, with a wall thickness of 0.5 mm. The impact velocity of the particles with a target was assumed to be 7.5 km / s. The number of integration cycles in all cases of calculation was assumed to be 1000. The rate of flying debris fragments of the target material as a function of the h / d ratio (h - the thickness of the target, / d - the diameter of a sphere or a cylinder end is obtained. In simulation the sample picture obtained coincides both with results of experimental study carried out at the Tomsk State Technical University and  with results described in the literature.

  11. Dynamical evolution of space debris on high-elliptical orbits near high-order resonance zones

    Science.gov (United States)

    Kuznetsov, Eduard; Zakharova, Polina

    Orbital evolution of objects on Molniya-type orbits is considered near high-order resonance zones. Initial conditions correspond to high-elliptical orbits with the critical inclination 63.4 degrees. High-order resonances are analyzed. Resonance orders are more than 5 and less than 50. Frequencies of perturbations caused by the effect of sectorial and tesseral harmonics of the Earth's gravitational potential are linear combinations of the mean motion of a satellite, angular velocities of motion of the pericenter and node of its orbit, and the angular velocity of the Earth. Frequencies of perturbations were calculated by taking into account secular perturbations from the Earth oblateness, the Moon, the Sun, and a solar radiation pressure. Resonance splitting effect leads to three sub-resonances. The study of dynamical evolution on long time intervals was performed on the basis of the results of numerical simulation. We used "A Numerical Model of the Motion of Artificial Earth's Satellites", developed by the Research Institute of Applied Mathematics and Mechanics of the Tomsk State University. The model of disturbing forces taken into account the main perturbing factors: the gravitational field of the Earth, the attraction of the Moon and the Sun, the tides in the Earth’s body, the solar radiation pressure, taking into account the shadow of the Earth, the Poynting-Robertson effect, and the atmospheric drag. Area-to-mass ratio varied from small values corresponding to satellites to big ones corresponding to space debris. The locations and sizes of resonance zones were refined from numerical simulation. The Poynting-Robertson effect results in a secular decrease in the semi-major axis of a spherically symmetrical satellite. In resonance regions the effect weakens slightly. Reliable estimates of secular perturbations of the semi-major axis were obtained from the numerical simulation. Under the Poynting-Robertson effect objects pass through the regions of high

  12. Comparing long-term projections of the space debris environment to real world data - Looking back to 1990

    Science.gov (United States)

    Radtke, Jonas; Stoll, Enrico

    2016-10-01

    Long-term projections of the space debris environment are commonly used to assess the trends within different scenarios for the assumed future development of spacefaring. General scenarios investigated include business-as-usual cases in which spaceflight is performed as today and mitigation scenarios, assuming the implementation of Space Debris Mitigation Guidelines at different advances or the effectiveness of more drastic measures, such as active debris removal. One problem that always goes along with the projection of a system's behaviour in the future is that affecting parameters, such as the launch rate, are unpredictable. It is common to look backwards and re-model the past in other fields of research. This is a rather difficult task for spaceflight as it is still quite young, and furthermore mostly influenced by drastic politic changes, as the break-down of the Soviet Union in the end of the 1980s. Furthermore, one major driver of the evolution of the number of on-orbit objects turn out to be collisions between objects. As of today, these collisions are, fortunately, very rare and therefore, a real-world-data modelling approach is difficult. Nevertheless, since the end of the cold war more than 20 years of a comparably stable evolution of spaceflight activities have passed. For this study, this period is used in a comparison between the real evolution of the space debris environment and that one projected using the Institute of Space System's in-house tool for long-term assessment LUCA (Long-Term Utility for Collision Analysis). Four different scenarios are investigated in this comparison; all of them have the common starting point of using an initial population for 1st May 1989. The first scenario, which serves as reference, is simply taken from MASTER-2009. All launch and mission related objects from the Two Line Elements (TLE) catalogue and other available sources are included. All events such as explosion and collision events have been re-modelled as

  13. Electron microscope observations of impact crater debris amongst contaminating particulates on materials surfaces exposed in space in low-Earth orbit

    Science.gov (United States)

    Murr, L. E.; Rivas, J. M.; Quinones, S.; Niou, C.-S.; Advani, A. H.; Marquez, B.

    1993-01-01

    Debris particles extracted from a small sampling region on the leading edge of the Long Duration Exposure Facility (LDEF) spacecraft have been examined by analytical transmission electron microscopy and the elemental frequency observed by energy-dispersive X-ray spectrometry and compared with upper atmosphere (Earth) particle elemental frequency and the average elemental compositions of interplanetary dust particles. A much broader elemental distribution was observed for the exposed spacecraft surface debris milieu. Numerous metal microfragment analyses, particularly aluminum and stainless steel, were compared with scanning electron microscope observations-of impact crater features, and the corresponding elemental spectra on selected LDEF aluminium tray clamps and stainless steel bolts. The compositions and melt features for these impact craters and ejecta have been shown to be consistent with microcrystalline debris fragments in the case of aluminum, and these observations suggest an ever changing debris milieu on exposed surfaces for space craft and space system materials.

  14. Threats to U.S. National Security Interests in Space: Orbital Debris Mitigation and Removal

    Science.gov (United States)

    2014-01-08

    Analytical Graphics, Inc., offers SOCRATES —Satellite Orbital Conjunction Reports Assessing Threatening Encounters in Space—on pending conjunctions over...the coming week. SOCRATES predicted a close approach between Iridium 33 and Cosmos 2251 of 584 m (1,916 ft.) at the time of the actual collision and... methods to slow or stop the formation of a debris belt. Donald J. Kessler and Burton G. Cour-Palais, “Collision Frequency of Artificial Satellites: The

  15. LDEF- 69 Months in Space. Second Post-Retrieval Symposium, Part 2

    Science.gov (United States)

    1992-06-01

    for Craters Formed by High-Velocity Projectiles." Hypervelocity Impact, 3rd Symposium, Armour Research Foundation of Illinois Inst. of Technology...The crater visible in Figure 1 c is substantially smoother than either of the previous features and is draped with a thin melt layer containing

  16. DEBRIS DISKS AROUND SOLAR-TYPE STARS: OBSERVATIONS OF THE PLEIADES WITH THE SPITZER SPACE TELESCOPE

    International Nuclear Information System (INIS)

    Sierchio, J. M.; Rieke, G. H.; Su, K. Y. L.; Plavchan, P.; Stauffer, J. R.; Gorlova, N. I.

    2010-01-01

    We present Spitzer MIPS observations at 24 μm of 37 solar-type stars in the Pleiades and combine them with previous observations to obtain a sample of 71 stars. We report that 23 stars, or 32% ± 6.8%, have excesses at 24 μm at least 10% above their photospheric emission. We compare our results with studies of debris disks in other open clusters and with a study of A stars to show that debris disks around solar-type stars at 115 Myr occur at nearly the same rate as around A-type stars. We analyze the effects of binarity and X-ray activity on the excess flux. Stars with warm excesses tend not to be in equal-mass binary systems, possibly due to clearing of planetesimals by binary companions in similar orbits. We find that the apparent anti-correlations in the incidence of excess and both the rate of stellar rotation and also the level of activity as judged by X-ray emission are statistically weak.

  17. The New Horizons and Hubble Space Telescope search for rings, dust, and debris in the Pluto-Charon system

    Science.gov (United States)

    Lauer, Tod R.; Throop, Henry B.; Showalter, Mark R.; Weaver, Harold A.; Stern, S. Alan; Spencer, John R.; Buie, Marc W.; Hamilton, Douglas P.; Porter, Simon B.; Verbiscer, Anne J.; Young, Leslie A.; Olkin, Cathy B.; Ennico, Kimberly; New Horizons Science Team

    2018-02-01

    We conducted an extensive search for dust or debris rings in the Pluto-Charon system before, during, and after the New Horizons encounter in July 2015. Methodologies included attempting to detect features by back-scattered light during the approach to Pluto (phase angle α ∼ 15°), in situ detection of impacting particles, a search for stellar occultations near the time of closest approach, and by forward-scattered light imaging during departure (α ∼ 165°). An extensive search using the Hubble Space Telescope (HST) prior to the encounter also contributed to the final ring limits. No rings, debris, or dust features were observed, but our new detection limits provide a substantially improved picture of the environment throughout the Pluto-Charon system. Searches for rings in back-scattered light covered the range 35,000-250,000 km from the system barycenter, a zone that starts interior to the orbit of Styx, the innermost minor satellite, and extends out to four times the orbital radius of Hydra, the outermost known satellite. We obtained our firmest limits using data from the New Horizons LORRI camera in the inner half of this region. Our limits on the normal I/F of an unseen ring depends on the radial scale of the rings: 2 ×10-8 (3σ) for 1500 km wide rings, 1 ×10-8 for 6000 km rings, and 7 ×10-9 for 12,000 km rings. Beyond ∼ 100, 000 km from Pluto, HST observations limit normal I/F to ∼ 8 ×10-8 . Searches for dust features from forward-scattered light extended from the surface of Pluto to the Pluto-Charon Hill sphere (rHill = 6.4 ×106 km). No evidence for rings or dust clouds was detected to normal I/F limits of ∼ 8.9 ×10-7 on ∼ 104 km scales. Four stellar occulation observations also probed the space interior to Hydra, but again no dust or debris was detected. The Student Dust Counter detected one particle impact 3.6 × 106 km from Pluto, but this is consistent with the interplanetary space environment established during the cruise of New

  18. Integrity assessment of the spacecraft subjected to the hypervelocity impact by ceramic and metal projectiles simulating space debris and micrometeoroids

    International Nuclear Information System (INIS)

    Katayama, Masahide; Takeba, Atsushi; Nitta, Kumi; Kawakita, Shirou; Matsumoto, Haruhisa; Kitazawa, Yukihito

    2010-01-01

    In order to establish the guidelines for the protection of unmanned spacecrafts from the space debris and micrometeoroid impacts, the experimental and numerical investigations have been conducted at Japan Aerospace Exploration Agency. This paper presents mainly its numerical methodology, especially from the viewpoint of highly non-linear and dynamic material model: i.e. the equation of state, constitutive model and fracture or failure model, including a brittle material model for ceramics and an equation of state for the shock-induced vaporization accompanied by hypervelocity impact. The experimental results of hypervelocity impact by two-stage light-gas gun and plasma drag gun are compared with corresponding numerical simulation results by using a hydrocode, and both results are demonstrated to be overall in good agreement with each other.

  19. Integrity assessment of the spacecraft subjected to the hypervelocity impact by ceramic and metal projectiles simulating space debris and micrometeoroids

    Energy Technology Data Exchange (ETDEWEB)

    Katayama, Masahide, E-mail: masahide.katayama@ctc-g.co.jp [Science and Engineering Systems Division, ITOCHU Techno-Solutions, 3-2-5, Kasumigaseki, Chiyoda-ku, Tokyo 100-6080 (Japan); Materials and Structures Laboratory, Tokyo Institute of Technology, 4259, Nagatsuta, Midori-ku, Yokohama-shi, Kanagawa 226-8503 (Japan); Takeba, Atsushi [Science and Engineering Systems Division, ITOCHU Techno-Solutions, 3-2-5, Kasumigaseki, Chiyoda-ku, Tokyo 100-6080 (Japan); Nitta, Kumi; Kawakita, Shirou; Matsumoto, Haruhisa [Aerospace Research and Development Directorate, Japan Aerospace Exploration Agency, 2-1-1, Sengen, Tsukuba-city, Ibaraki 305-8505 (Japan); Kitazawa, Yukihito [Aerospace Research and Development Directorate, Japan Aerospace Exploration Agency, 2-1-1, Sengen, Tsukuba-city, Ibaraki 305-8505 (Japan); Aero-Engine and Space Operations, IHI Corporation, 3-1-1, Toyosu, Koto-ku, Tokyo 135-8710 (Japan)

    2010-10-15

    In order to establish the guidelines for the protection of unmanned spacecrafts from the space debris and micrometeoroid impacts, the experimental and numerical investigations have been conducted at Japan Aerospace Exploration Agency. This paper presents mainly its numerical methodology, especially from the viewpoint of highly non-linear and dynamic material model: i.e. the equation of state, constitutive model and fracture or failure model, including a brittle material model for ceramics and an equation of state for the shock-induced vaporization accompanied by hypervelocity impact. The experimental results of hypervelocity impact by two-stage light-gas gun and plasma drag gun are compared with corresponding numerical simulation results by using a hydrocode, and both results are demonstrated to be overall in good agreement with each other.

  20. Post-Newtonian equations of motion for LEO debris objects and space-based acquisition, pointing and tracking laser systems

    Science.gov (United States)

    Gambi, J. M.; García del Pino, M. L.; Gschwindl, J.; Weinmüller, E. B.

    2017-12-01

    This paper deals with the problem of throwing middle-sized low Earth orbit debris objects into the atmosphere via laser ablation. The post-Newtonian equations here provided allow (hypothetical) space-based acquisition, pointing and tracking systems endowed with very narrow laser beams to reach the pointing accuracy presently prescribed. In fact, whatever the orbital elements of these objects may be, these equations will allow the operators to account for the corrections needed to balance the deviations of the line of sight directions due to the curvature of the paths the laser beams are to travel along. To minimize the respective corrections, the systems will have to perform initial positioning manoeuvres, and the shooting point-ahead angles will have to be adapted in real time. The enclosed numerical experiments suggest that neglecting these measures will cause fatal errors, due to differences in the actual locations of the objects comparable to their size.

  1. 12th Symposium on Space Nuclear Power and Propulsion. Conference on Alternative Power from Space (APFS),Conference on Accelerator-Driven Transmutation Technologies and Applications (A-DTTA)

    International Nuclear Information System (INIS)

    Mohamed, S.E.

    1995-01-01

    These proceedings represent papers presented at the 12th symposium on Space Nuclear Power and Propulsion held in Albuquerque, New Mexico. The symposium theme was ''commercialization and technology transfer''. The topics discussed include: wireless power transmission, solar power from space next generation spacecraft, space power electronics and power management, flight testing of components, manufacturing and processing of materials, nuclear propulsion, reactors and shielding and many others of interest to the scientific community representing industry, government and academic institutions. There were 163 papers presented at the conference and 60 have been abstracted for the Energy Science and Technology database

  2. Fault-tolerant feature-based estimation of space debris rotational motion during active removal missions

    Science.gov (United States)

    Biondi, Gabriele; Mauro, Stefano; Pastorelli, Stefano; Sorli, Massimo

    2018-05-01

    One of the key functionalities required by an Active Debris Removal mission is the assessment of the target kinematics and inertial properties. Passive sensors, such as stereo cameras, are often included in the onboard instrumentation of a chaser spacecraft for capturing sequential photographs and for tracking features of the target surface. A plenty of methods, based on Kalman filtering, are available for the estimation of the target's state from feature positions; however, to guarantee the filter convergence, they typically require continuity of measurements and the capability of tracking a fixed set of pre-defined features of the object. These requirements clash with the actual tracking conditions: failures in feature detection often occur and the assumption of having some a-priori knowledge about the shape of the target could be restrictive in certain cases. The aim of the presented work is to propose a fault-tolerant alternative method for estimating the angular velocity and the relative magnitudes of the principal moments of inertia of the target. Raw data regarding the positions of the tracked features are processed to evaluate corrupted values of a 3-dimentional parameter which entirely describes the finite screw motion of the debris and which primarily is invariant on the particular set of considered features of the object. Missing values of the parameter are completely restored exploiting the typical periodicity of the rotational motion of an uncontrolled satellite: compressed sensing techniques, typically adopted for recovering images or for prognostic applications, are herein used in a completely original fashion for retrieving a kinematic signal that appears sparse in the frequency domain. Due to its invariance about the features, no assumptions are needed about the target's shape and continuity of the tracking. The obtained signal is useful for the indirect evaluation of an attitude signal that feeds an unscented Kalman filter for the estimation of

  3. De-Orbiting of Space Debris by Means of a Towering Cable and a Single Thruster Spaceship: Whiplash and Tail Wagging Effects

    Science.gov (United States)

    da Cruz Pacheco, Gabriel Felippe; Carpentier, Benjamin; Petit, Nicolas

    2013-08-01

    This papers exposes two difficulties that are likely to take place during the towing of a space debris. These effects, which could trouble de-orbitation strategies, are visible on simple simulations based on a model of coupled rigid-bodies dynamics. We name them tail wagging and whiplash effects, respectively.

  4. IUTAM Symposium

    CERN Document Server

    Shioiri, Jumpei

    1996-01-01

    The IUTAM Symposium on Constitutive Relation in High/Very High Strain Rates (CRHVHSR) was held October 16 - 19, 1995, at Seminar House, Science University of Tokyo, under the sponsorship of IUTAM, Japan Society for the Promotion of Science, The Commemorative Association for the Japan World Exposition (1970), Inoue Foundation for Science, The Japan Society for Aeronautical and Space Sciences, and Science University of Tokyo. The proposal to hold the symposium was accepted by the General Assembly of IUT AM held in Haifa, Israel, in August 1992, and the scientists mentioned below were appointed by the Bureau of IUTAM to serve as members of the Scientific Committee. The main object of the symposium was to make a general survey of recent developments in the research of constitutive relations in high and very high strain rates and related problems in high velocity solid mechanics, and to explore further new ideas for dealing with unresolved problems of a fundamental nature as well as of practical importance. The su...

  5. A parallel algorithm for the initial screening of space debris collisions prediction using the SGP4/SDP4 models and GPU acceleration

    Science.gov (United States)

    Lin, Mingpei; Xu, Ming; Fu, Xiaoyu

    2017-05-01

    Currently, a tremendous amount of space debris in Earth's orbit imperils operational spacecraft. It is essential to undertake risk assessments of collisions and predict dangerous encounters in space. However, collision predictions for an enormous amount of space debris give rise to large-scale computations. In this paper, a parallel algorithm is established on the Compute Unified Device Architecture (CUDA) platform of NVIDIA Corporation for collision prediction. According to the parallel structure of NVIDIA graphics processors, a block decomposition strategy is adopted in the algorithm. Space debris is divided into batches, and the computation and data transfer operations of adjacent batches overlap. As a consequence, the latency to access shared memory during the entire computing process is significantly reduced, and a higher computing speed is reached. Theoretically, a simulation of collision prediction for space debris of any amount and for any time span can be executed. To verify this algorithm, a simulation example including 1382 pieces of debris, whose operational time scales vary from 1 min to 3 days, is conducted on Tesla C2075 of NVIDIA. The simulation results demonstrate that with the same computational accuracy as that of a CPU, the computing speed of the parallel algorithm on a GPU is 30 times that on a CPU. Based on this algorithm, collision prediction of over 150 Chinese spacecraft for a time span of 3 days can be completed in less than 3 h on a single computer, which meets the timeliness requirement of the initial screening task. Furthermore, the algorithm can be adapted for multiple tasks, including particle filtration, constellation design, and Monte-Carlo simulation of an orbital computation.

  6. An LDEF 2 dust instrument for discrimination between orbital debris and natural particles in near-Earth space

    Science.gov (United States)

    Tuzzolino, A. J.; Simpson, J. A.; Mckibben, R. B.; Voss, H. D.; Gursky, H.

    1993-01-01

    The characteristics of a space dust instrument which would be ideally suited to carry out near-Earth dust measurements on a possible Long Duraction Exposure Facility reflight mission (LDEF 2) is discussed. As a model for the trajectory portion of the instrument proposed for LDEF 2, the characteristics of a SPAce DUSt instrument (SPADUS) currently under development for flight on the USA ARGOS mission to measure the flux, mass, velocity, and trajectory of near-Earth dust is summarized. Since natural (cosmic) dust and man-made dust particles (orbital debris) have different velocity and trajectory distributions, they are distinguished by means of the SPADUS velocity/trajectory information. The SPADUS measurements will cover the dust mass range approximately 5 x 10(exp -12) g (2 microns diameter) to approximately 1 x 10(exp -5) g (200 microns diameter), with an expected mean error in particle trajectory of approximately 7 deg (isotropic flux). Arrays of capture cell devices positioned behind the trajectory instrumentation would provide for Earth-based chemical and isotopic analysis of captured dust. The SPADUS measurement principles, characteristics, its role in the ARGOS mission, and its application to an LDEF 2 mission are summarized.

  7. Eliminating Space Debris: Applied Technology and Policy Prescriptions, Fall 2007 - Project 07-02

    Science.gov (United States)

    2008-01-01

    Selfish maximization of the profit from property rights will lead to a socially efficient outcome. The negative externalities will be eliminated.52...Experiment (MSX)” MSX Celestial Backgrounds. 27 Dec. 2007 <http://www.ipac.caltech.edu/ipac/msx/msx.html> 155 Heyler, Gene “MSX Midcourse Space Experiment

  8. An Ontological Architecture for Orbital Debris Data

    OpenAIRE

    Rovetto, Robert J.

    2017-01-01

    The orbital debris problem presents an opportunity for inter-agency and international cooperation toward the mutually beneficial goals of debris prevention, mitigation, remediation, and improved space situational awareness (SSA). Achieving these goals requires sharing orbital debris and other SSA data. Toward this, I present an ontological architecture for the orbital debris domain, taking steps in the creation of an orbital debris ontology (ODO). The purpose of this ontological system is to ...

  9. Present status of the 4-m ILMT data reduction pipeline: application to space debris detection and characterization

    Science.gov (United States)

    Pradhan, Bikram; Delchambre, Ludovic; Hickson, Paul; Akhunov, Talat; Bartczak, Przemyslaw; Kumar, Brajesh; Surdej, Jean

    2018-04-01

    The 4-m International Liquid Mirror Telescope (ILMT) located at the ARIES Observatory (Devasthal, India) has been designed to scan at a latitude of +29° 22' 26" a band of sky having a width of about half a degree in the Time Delayed Integration (TDI) mode. Therefore, a special data-reduction and analysis pipeline to process online the large amount of optical data being produced has been dedicated to it. This requirement has led to the development of the 4-m ILMT data reduction pipeline, a new software package built with Python in order to simplify a large number of tasks aimed at the reduction of the acquired TDI images. This software provides astronomers with specially designed data reduction functions, astrometry and photometry calibration tools. In this paper we discuss the various reduction and calibration steps followed to reduce TDI images obtained in May 2015 with the Devasthal 1.3m telescope. We report here the detection and characterization of nine space debris present in the TDI frames.

  10. The International Symposium on Space Climate (2nd), Long-Term Changes in the Sun and their Effects in the Heliosphere and Plant Earth, held in Sinaia, Romania, on 13-16 September 2006

    National Research Council Canada - National Science Library

    2008-01-01

    This report summarizes the activities and statistics for the Second International Symposium of Space Climate organized by Astronomical Institute of the Romanian Academy in Sinaia, Romania, on 13-16...

  11. Interactions of the space debris environment with mega constellations-Using the example of the OneWeb constellation

    Science.gov (United States)

    Radtke, Jonas; Kebschull, Christopher; Stoll, Enrico

    2017-02-01

    Recently, several announcements have been published to deploy satellite constellations into Low Earth Orbit (LEO) containing several hundred to thousands of rather small sized objects. The purpose of these constellations is to provide a worldwide internet coverage, even to the remotest areas. Examples of these mega-constellations are one from SpaceX, which is announced to comprise of about 4000 satellites, the Norwegian STEAM network, which is told to contain 4257 satellites, and the OneWeb constellation, which forms one of the smaller constellations with 720 satellites. As example constellation, OneWeb has been chosen. From all announced constellation, OneWeb by far delivered most information, both in regards to constellation design and their plans to encounter space debris issues, which is the reason why it has been chosen for these analyses. In this paper, at first an overview of the planned OneWeb constellation setup is given. From this description, a mission life-cycle is deduced, splitting the complete orbital lifetime of the satellites into four phases. Following, using ESA-MASTER, for each of the mission phases the flux on both single constellations satellites and the complete constellation are performed and the collision probabilities are derived. The focus in this analysis is set on catastrophic collisions. This analysis is then varied parametrically for different operational altitudes of the constellation as well as different lifetimes with different assumptions for the success of post mission disposal (PMD). Following the to-be-expected mean number of collision avoidance manoeuvres during all active mission phases is performed using ARES from ESA's DRAMA tool suite. The same variations as during the flux analysis are considered. Lastly the characteristics of hypothetical OneWeb satellite fragmentation clouds, calculated using the NASA Breakup model, are described and the impact of collision clouds from OneWeb satellites on the constellation itself is

  12. Woody debris

    Science.gov (United States)

    Donna B. Scheungrab; Carl C. Trettin; Russ Lea; Martin F. Jurgensen

    2000-01-01

    Woody debris can be defined as any dead, woody plant material, including logs, branches, standing dead trees, and root wads. Woody debris is an important part of forest and stream ecosystems because it has a role in carbon budgets and nutrient cycling, is a source of energy for aquatic ecosystems, provides habitat for terrestrial and aquatic organisms, and contributes...

  13. Debris Disks in Aggregate: Using Hubble Space Telescope Coronagraphic Imagery to Understand the Scattered-Light Disk Detection Rate

    Science.gov (United States)

    Grady, Carol A.

    2011-01-01

    Despite more than a decade of coronagraphic imaging of debris disk candidate stars, only 16 have been imaged in scattered light. Since imaged disks provide our best insight into processes which sculpt disks, and can provide signposts of the presence of giant planets at distances which would elude radial velocity and transit surveys, we need to understand under what conditions we detect the disks in scattered light, how these disks differ from the majority of debris disks, and how to increase the yield of disks which are imaged with 0.1" angular resolution. In this talk, I will review what we have learned from a shallow HSTINICMOS NIR survey of debris disks, and present first results from our on-going HST /STIS optical imaging of bright scattered-light disks.

  14. Rapid Application of Space Effects for the Small Satellites Systems and Services Symposium

    Science.gov (United States)

    Tsairides, Demosthenes; Finley, Charles; Moretti, George

    2016-01-01

    NASA Ames Research Center (ARC) has engaged Military Branches, the Department of Defense, and other Government Agencies in successful partnerships to design, develop, deliver and support various space effects capabilities and space vehicles on timeline of need. Contracts with Industry are in place to execute operational and enabler missions using physical and informational infrastructures including Responsive Manufacturing capabilities and Digital Assurance. The intent is to establish a secure, web-enabled "store front" for ordering and delivering any capabilities required as defined by the users and directed by NASA ARC and Partner Organizations. The capabilities are envisioned to cover a broad range and include 6U CubeSats, 50-100 kg Space Vehicles, Modular Space Vehicle architecture variations, as well as rapid payload integration on various Bus options. The paper will discuss the efforts underway to demonstrate autonomous manufacturing of low-volume, high-value assets, to validate the ability of autonomous digital techniques to provide Mission Assurance, and to demonstrate cost savings through the identification, characterization, and utilization of Responsive Space components. The culmination of this effort will be the integration of several 6U satellites and their launch in 2016.

  15. Symbolic 'Lived Spaces' in Ancient Greek Lyric and the Heterotopia of the Symposium

    NARCIS (Netherlands)

    Heirman, J.; Heirman, J.; Klooster, J.

    2013-01-01

    This paper looks at the presentation of space in ancient Greek lyric poetry of the seventh through the fifth century BCE and its ideological function in the cultural-historical context. This poetry, by authors including Sappho, Solon and Pindar, comes after the Homeric epics about Troy and Odysseus

  16. Proceedings of the 20th International Symposium on Space Flight Dynamics

    Science.gov (United States)

    Woodard, Mark (Editor); Stengle, Tom (Editor)

    2007-01-01

    Topics include: Measuring Image Navigation and Registration Performance at the 3-Sigma Level Using Platinum Quality Landmarks; Flight Dynamics Performances of the MetOp A Satellite during the First Months of Operations; Visual Navigation - SARE Mission; Determining a Method of Enabling and Disabling the Integral Torque in the SDO Science and Inertial Mode Controllers; Guaranteeing Pointing Performance of the SDO Sun-Pointing Controllers in Light of Nonlinear Effects; SDO Delta H Mode Design and Analysis; Observing Mode Attitude Controller for the Lunar Reconnaissance Orbiter; Broken-Plane Maneuver Applications for Earth to Mars Trajectories; ExoMars Mission Analysis and Design - Launch, Cruise and Arrival Analyses; Mars Reconnaissance Orbiter Aerobraking Daily Operations and Collision Avoidance; Mars Reconnaissance Orbiter Interplanetary Cruise Navigation; Motion Parameters Determination of the SC and Phobos in the Project Phobos-Grunt; GRAS NRT Precise Orbit Determination: Operational Experience; Orbit Determination of LEO Satellites for a Single Pass through a Radar: Comparison of Methods; Orbit Determination System for Low Earth Orbit Satellites; Precise Orbit Determination for ALOS; Anti-Collision Function Design and Performances of the CNES Formation Flying Experiment on the PRISMA Mission; CNES Approaching Guidance Experiment within FFIORD; Maneuver Recovery Analysis for the Magnetospheric Multiscale Mission; SIMBOL-X: A Formation Flying Mission on HEO for Exploring the Universe; Spaceborne Autonomous and Ground Based Relative Orbit Control for the TerraSAR-X/TanDEM-X Formation; First In-Orbit Experience of TerraSAR-X Flight Dynamics Operations; Automated Target Planning for FUSE Using the SOVA Algorithm; Space Technology 5 Post-Launch Ground Attitude Estimation Experience; Standardizing Navigation Data: A Status Update; and A Study into the Method of Precise Orbit Determination of a HEO Orbiter by GPS and Accelerometer.

  17. Bernard Schutz : "Fundamental physics looks forwards Space"; symposium in honour of Maurice Jacob on 27 March 1998

    CERN Multimedia

    Laurent Guiraud

    1998-01-01

    On the occasion of the 65th birthday of Maurice Jacob, his friends are organizing, together with CERN, a symposium presenting some of the scientific fields to which Maurice Jacob has made decisive contributions during his career or in which he has a

  18. Maurice Jacob : "Fundamental physics looks forwards Space"; symposium in honour of Maurice Jacob on 27 March 1998

    CERN Multimedia

    Laurent Guiraud

    1998-01-01

    On the occasion of the 65th birthday of Maurice Jacob, his friends are organizing, together with CERN, a symposium presenting some of the scinetific fields to which M Jacob has made decisive contributions during his career or in which he has a person

  19. Symposium Introduction: Studies of women and men in bed and in space

    Science.gov (United States)

    Hargens, Alan

    INTRODUCTION: Some gender differences in response to microgravity have been noted previously. Furthermore current exercise systems for space flight do not provide loads equal to those on Earth. We hypothesized that supine LBNP treadmill exercise combined with flywheel resistive exercise maintains upright physiologic responses and tissue mass following 30-days and 60-days of head-down tilt (HDT) bed rest (BR). METHODS: For WISE-2005, 16 healthy women (age 25-40 years) underwent a 20-day baseline period, followed by 60-days continuous HDT (-6 degrees) BR and then by recovery for an additional 20-days. Women were assigned to either a control group (CON, n=8) who performed no exercise or to an exercise group (EX, n=8). EX subjects performed a 40-min, variable intensity (40-80 RESULTS: For WISE-2005, post-BR orthostatic tolerance (time to pre-syncope) was signifi- cantly better in the EX group than that in the CON group (p¡ 0.05). On BR day 50, heart rate (HR) was elevated at supine rest for the CON, but not for EX. Moreover, during a supine LBNP stress test at 30 mmHg, the HR increase from Pre-BR to BR day 50 for the EX group was less than that for CON. Heart mass decreased significantly in CON, but increased signifi- cantly in EX. Post-BR upright VO2pk, muscle strength, and endurance decreased significantly in CON, but were preserved in EX. Post-BR bone resorption was greater than pre-BR in both groups. Helical peptide and N-telopeptide excretions increased in both CON and EX. However, bone-specific alkaline phosphatase, a bone formation marker, tended to be higher in EX than in CON. DISCUSSION AND CONCLUSIONS: Previously we found that orthostatic tolerance is lower in women than that in men. For WISE-2005, supine treadmill exercise protocol within LBNP along with flywheel resistive exercise maintains orthostatic responses, upright exercise capacity, heart mass, muscle strength and endurance during 60-days HDT BR. By comparison with previous studies, cardiac atrophy

  20. Wholesale debris removal from LEO

    Science.gov (United States)

    Levin, Eugene; Pearson, Jerome; Carroll, Joseph

    2012-04-01

    Recent advances in electrodynamic propulsion make it possible to seriously consider wholesale removal of large debris from LEO for the first time since the beginning of the space era. Cumulative ranking of large groups of the LEO debris population and general limitations of passive drag devices and rocket-based removal systems are analyzed. A candidate electrodynamic debris removal system is discussed that can affordably remove all debris objects over 2 kg from LEO in 7 years. That means removing more than 99% of the collision-generated debris potential in LEO. Removal is performed by a dozen 100-kg propellantless vehicles that react against the Earth's magnetic field. The debris objects are dragged down and released into short-lived orbits below ISS. As an alternative to deorbit, some of them can be collected for storage and possible in-orbit recycling. The estimated cost per kilogram of debris removed is a small fraction of typical launch costs per kilogram. These rates are low enough to open commercial opportunities and create a governing framework for wholesale removal of large debris objects from LEO.

  1. India Symposium

    Indian Academy of Sciences (India)

    JNCASR

    Impact of Women's research in Science and Technology in the new millennium'. The. Symposium will showcase the work done by young Indian Women Scientists in different branches of Science and Engineering, at a wide spectrum of Research ...

  2. IUTAM Symposium

    CERN Document Server

    1995-01-01

    The International Union of Theoretical and Applied Mechanics (IUTAM) decided in 1992 to sponsor the fourth Symposium on Laminar-Turbulent Transition, Sendai/Japan, 1994. The objectives of the present Symposium were to deepen the fundamental knowledge of stability and laminar­ turbulent transition in three-dimensional and compressible flows and to contribute to recent developing technologies in the field. This Symposium followed the three previous IUTAM-Symposia (Stuttgart 1979, Novosibirsk 1984 and Toulouse 1989). The Scientific Committee selected two keynote lectures and 62 technical papers. The Symposium was held on the 5th to 9th of September, 1994, at the Sendai International Center in Sendai. The participants were 82 scientists from 10 countries. The keynote lectures have critically reviewed recent development of researches concerning the laminar-to-turbulent transition phenomena from the fundamental and the application aspects. Many papers presented were concerned about the detailed mechanism of the bo...

  3. A Symposium.

    Science.gov (United States)

    Rachal, John R.

    2003-01-01

    Uses the framework of a symposium to present an imagined discussion by historical figures about whether and how knowledge might be acquired. Discussants include Democritus, Protagoras, Heraclitus, Socrates, Jesus, Gorgias, Nietzsche, Buddha, and Kierkegaard. (Contains 40 endnotes.) (SK)

  4. JSC Orbital Debris Website Description

    Science.gov (United States)

    Johnson, Nicholas L.

    2006-01-01

    Purpose: The website provides information about the NASA Orbital Debris Program Office at JSC, which is the lead NASA center for orbital debris research. It is recognized world-wide for its leadership in addressing orbital debris issues. The NASA Orbital Debris Program Office has taken the international lead in conducting measurements of the environment and in developing the technical consensus for adopting mitigation measures to protect users of the orbital environment. Work at the center continues with developing an improved understanding of the orbital debris environment and measures that can be taken to control its growth. Major Contents: Orbital Debris research is divided into the following five broad efforts. Each area of research contains specific information as follows: 1) Modeling - NASA scientists continue to develop and upgrade orbital debris models to describe and characterize the current and future debris environment. Evolutionary and engineering models are described in detail. Downloadable items include a document in PDF format and executable software. 2) Measurements - Measurements of near-Earth orbital debris are accomplished by conducting ground-based and space-based observations of the orbital debris environment. The data from these sources provide validation of the environment models and identify the presence of new sources. Radar, optical and surface examinations are described. External links to related topics are provided. 3) Protection - Orbital debris protection involves conducting hypervelocity impact measurements to assess the risk presented by orbital debris to operating spacecraft and developing new materials and new designs to provide better protection from the environment with less weight penalty. The data from this work provides the link between the environment defined by the models and the risk presented by that environment to operating spacecraft and provides recommendations on design and operations procedures to reduce the risk as

  5. Colisional Cloud Debris and Propelled Evasive Maneuvers

    Science.gov (United States)

    Ferreira, L. S.; Jesus, A. D. C.; Carvalho, T. C. F.; Sousa, R. R.

    2017-10-01

    Space debris clouds exist at various altitudes in the environment outside the Earth. Fragmentation of debris and/or collision between the debris of a cloud increases the amount of debris, producing smaller debris. This event also increases significantly the chances of collision with operational vehicles in orbit. In this work we study clouds of debris that are close to a spacecraft in relation to its distance from the center of the Earth. The results show several layers of colliding debris depending on their size over time of evasive maneuvers of the vehicle. In addition, we have tested such maneuvers for propulsion systems with a linear and exponential mass variation model. The results show that the linear propulsion system is more efficient.

  6. Independent Review of U.S. and Russian Probabilistic Risk Assessments for the International Space Station Mini Research Module #2 Micrometeoroid and Orbital Debris Risk

    Science.gov (United States)

    Squire, Michael D.

    2011-01-01

    The Mini-Research Module-2 (MRM-2), a Russian module on the International Space Station, does not meet its requirements for micrometeoroid and orbital debris probability of no penetration (PNP). To document this condition, the primary Russian Federal Space Agency ISS contractor, S.P. Korolev Rocket and Space Corporation-Energia (RSC-E), submitted an ISS non-compliance report (NCR) which was presented at the 5R Stage Operations Readiness Review (SORR) in October 2009. In the NCR, RSC-E argued for waiving the PNP requirement based on several factors, one of which was the risk of catastrophic failure was acceptably low at 1 in 11,100. However, NASA independently performed an assessment of the catastrophic risk resulting in a value of 1 in 1380 and believed that the risk at that level was unacceptable. The NASA Engineering and Safety Center was requested to evaluate the two competing catastrophic risk values and determine which was more accurate. This document contains the outcome of the assessment.

  7. IUTAM Symposium

    CERN Document Server

    Whitelaw, James; Wung, T

    1992-01-01

    A Symposium on Aerothermodynamics of Combustors was held at the Institute of Applied Mechanics of the National Taiwan University from 3 to 5 June 1991 and was attended by 130 delegates from eight countries. The topics of the forty formal presentations included measurements and calculations of isothermal simulations and of combusting flows with one and two phases, and with consideration of configurations ranging from simple diffusion to gas-turbine flows. The discussions inside and outside of the Symposium Hall were lively and an open forum session demonstrated the range of opinions currently and strongly held. The International Union of Theoretical and Applied Mechanics initiated the Symposium under the chairmanship of Professor R S L Lee and with the Scientific Committee listed below. It benefited from sponsorship, again as listed below, and from contributors who presented interesting and up-to-date descriptions of their research. Invited lectures were delivered by Professors R Bilger and F Weinberg and set ...

  8. To Ensure the Integrity of the Cryogenic Propellant Depot Tank Within the Expected Radiation and Space Debris Environment, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — HyPerComp Engineering, Inc. (HEI) proposes to develop well characterized, structurally reliable filament wound composite pressure vessels for use in both cryogenic...

  9. Fuel wood symposium; Symposium Energieholz

    Energy Technology Data Exchange (ETDEWEB)

    Wild, C.; Wauer, A. (comps.)

    2001-07-01

    The Bavarian State Institute of Forestry (LWF) organised a 'Fuel Wood Symposium' in Freising-Weihenstephan on 17.11.2000. The purpose of this specialist conference was to give an overview of the use of biomass, especially wood, as an source of energy. (orig.) [German] Die Bayerische Landesanstalt fuer Wald und Forstwirtschaft richtete am 17.11.2000 in Freising-Weihenstephan das 'Symposium Energieholz' aus. Ziel der Fachtagung war es, einen Ueberblick ueber die energetische Nutzung von Biomasse, insbesondere Holz, zu geben. (orig.)

  10. The human quest in space; Proceedings of the Twenty-fourth Goddard Memorial Symposium, Greenbelt, MD, Mar. 20, 21, 1986

    Science.gov (United States)

    Burdett, Gerald L. (Editor); Soffen, Gerald A. (Editor)

    1987-01-01

    Papers are presented on the Space Station, materials processing in space, the status of space remote sensing, the evolution of space infrastructure, and the NASA Teacher Program. Topics discussed include visionary technologies, the effect of intelligent machines on space operations, future information technology, and the role of nuclear power in future space missions. Consideration is given to the role of humans in space exploration; medical problems associated with long-duration space flights; lunar and Martian settlements, and Biosphere II (the closed ecology project).

  11. Symposium Highlights

    International Nuclear Information System (INIS)

    Owen-Whitred, K.

    2015-01-01

    Overview/Highlights: To begin, I'd like to take a moment to highlight some of the novel elements of this Symposium as compared to those that have been held in the past. For the first time ever, this Symposium was organized around five concurrent sessions, covering over 300 papers and presentations. These sessions were complemented by an active series of exhibits put on by vendors, universities, ESARDA, INMM, and Member State Support Programmes. We also had live demonstrations throughout the week on everything from software to destructive analysis to instrumentation, which provided the participants the opportunity to see recent developments that are ready for implementation. I'm sure you all had a chance to observe - and, more importantly, interact with - the electronic Poster, or ePoster format used this past week. This technology was used here for the first time ever by the IAEA, and I'm sure was a first for many of us as well. The ePoster format allowed participants to interact with the subject matter, and the subject matter experts, in a dynamic, engaging way. In addition to the novel technology used here, I have to say that having the posters strategically embedded in the sessions on the same topic, by having each poster author introduce his or her topic to the assembled group in order to lure us to the poster area during the breaks, was also a novel and highly effective technique. A final highlight I'd like to touch on in terms of the Symposium organization is the diversity of participation. This chart shows the breakdown by geographical distribution for the Symposium, in terms of participants. There are no labels, so don't try to read any, I simply wanted to demonstrate that we had great representation in terms of both the Symposium participants in general and the session chairs more specifically-and on that note, I would just mention here that 59 Member States participated in the Symposium. But what I find especially interesting and

  12. 43rd Aerospace Mechanisms Symposium

    Science.gov (United States)

    Boesiger, Edward A.

    2016-01-01

    The Aerospace Mechanisms Symposium (AMS) provides a unique forum for those active in the design, production and use of aerospace mechanisms. A major focus is the reporting of problems and solutions associated with the development and flight certification of new mechanisms. Sponsored and organized by the Mechanisms Education Association, responsibility for hosting the AMS is shared by the National Aeronautics and Space Administration and Lockheed Martin Space Systems Company (LMSSC). Now in its 43rd symposium, the AMS continues to be well attended, attracting participants from both the U.S. and abroad. The 43rd AMS was held in Santa Clara, California on May 4, 5 and 6, 2016. During these three days, 42 papers were presented. Topics included payload and positioning mechanisms, components such as hinges and motors, CubeSats, tribology, and mechanism testing. Hardware displays during the supplier exhibit gave attendees an opportunity to meet with developers of current and future mechanism components. The high quality of this symposium is a result of the work of many people, and their efforts are gratefully acknowledged. This extends to the voluntary members of the symposium organizing committee representing the eight NASA field centers, LMSSC, and the European Space Agency. Appreciation is also extended to the session chairs, the authors, and particularly the personnel at ARC responsible for the symposium arrangements and the publication of these proceedings. A sincere thank you also goes to the symposium executive committee who is responsible for the year-to-year management of the AMS, including paper processing and preparation of the program. The use of trade names of manufacturers in this publication does not constitute an official endorsement of such products or manufacturers, either expressed or implied, by the National Aeronautics and Space Administration.

  13. Spin symposium

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1989-01-15

    The recent 8th International Symposium on High Energy Spin Physics at the University of Minnesota in Minneapolis, Minnesota, opened with a bang when L. Pondrom (Wisconsin), donning a hard hat borrowed from construction workers, ventured that 'spin, the notorious inessential complication of hadronic physics, is finally telling us what real QCD (quantum chromodynamics, the field theory of quarks and gluons) looks like.' He was referring to an animated discussion on the meaning of the recent spin oriented (polarized) scattering results from the European Muon Collaboration (EMC) at CERN and reported at the Symposium by R. Garnet (Liverpool) and P. Schuler (Yale) which show that the proton spin is not simply a reflection of the spins of its constituent quarks.

  14. IUTAM Symposium

    CERN Document Server

    Stefanou, George

    2014-01-01

    This book contains the proceedings of the IUTAM Symposium on Multiscale Modeling and Uncertainty Quantification of Materials and Structures that was held at Santorini, Greece, September 9 – 11, 2013. It consists of 20 chapters which are divided in five thematic topics: Damage and fracture, homogenization, inverse problems–identification, multiscale stochastic mechanics and stochastic dynamics. Over the last few years, the intense research activity at microscale and nanoscale reflected the need to account for disparate levels of uncertainty from various sources and across scales. As even over-refined deterministic approaches are not able to account for this issue, an efficient blending of stochastic and multiscale methodologies is required to provide a rational framework for the analysis and design of materials and structures. The purpose of this IUTAM Symposium was to promote achievements in uncertainty quantification combined with multiscale modeling and to encourage research and development in this grow...

  15. 11. European cosmic ray symposium

    International Nuclear Information System (INIS)

    1989-03-01

    The biannual Symposium includes all aspects of cosmic ray research. The scientific programme was organized under three main headings: Cosmic rays in the heliosphere, Cosmic rays in the interstellar and extragalactic space, Properties of high-energy interactions as studied by cosmic rays. Seven invited talks were indexed seprately for the INIS database. (R.P.)

  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. Space commercialization: Launch vehicles and programs; Symposium on Space Commercialization: Roles of Developing Countries, Nashville, TN, Mar. 5-10, 1989, Technical Papers

    International Nuclear Information System (INIS)

    Shahrokhi, F.; Greenberg, J.S.; Al-saud, Turki.

    1990-01-01

    The present volume on progress in astronautics and aeronautics discusses the advent of commercial space, broad-based space education as a prerequisite for space commercialization, and obstacles to space commercialization in the developing world. Attention is given to NASA directions in space propulsion for the year 2000 and beyond, possible uses of the external tank in orbit, power from the space shuttle and from space for use on earth, Long-March Launch Vehicles in the 1990s, the establishment of a center for advanced space propulsion, Pegasus as a key to low-cost space applications, legal problems of developing countries' access to space launch vehicles, and international law of responsibility for remote sensing. Also discussed are low-cost satellites and satellite launch vehicles, satellite launch systems of China; Raumkurier, the German recovery program; and the Ariane transfer vehicle as logistic support to Space Station Freedom

  18. Second AIAA/NASA USAF Symposium on Automation, Robotics and Advanced Computing for the National Space Program

    Science.gov (United States)

    Myers, Dale

    1987-01-01

    An introduction is given to NASA goals in the development of automation (expert systems) and robotics technologies in the Space Station program. Artificial intelligence (AI) has been identified as a means to lowering ground support costs. Telerobotics will enhance space assembly, servicing and repair capabilities, and will be used for an estimated half of the necessary EVA tasks. The general principles guiding NASA in the design, development, ground-testing, interactions with industry and construction of the Space Station component systems are summarized. The telerobotics program has progressed to a point where a telerobot servicer is a firm component of the first Space Station element launch, to support assembly, maintenance and servicing of the Station. The University of Wisconsin has been selected for the establishment of a Center for the Commercial Development of Space, specializing in space automation and robotics.

  19. Orbital Debris and NASA's Measurement Program

    Science.gov (United States)

    Africano, J. L.; Stansbery, E. G.

    2002-05-01

    Since the launch of Sputnik in 1957, the number of manmade objects in orbit around the Earth has dramatically increased. The United States Space Surveillance Network (SSN) tracks and maintains orbits on over nine thousand objects down to a limiting diameter of about ten centimeters. Unfortunately, active spacecraft are only a small percentage ( ~ 7%) of this population. The rest of the population is orbital debris or ``space junk" consisting of expended rocket bodies, dead payloads, bits and pieces from satellite launches, and fragments from satellite breakups. The number of these smaller orbital debris objects increases rapidly with decreasing size. It is estimated that there are at least 130,000 orbital debris objects between one and ten centimeters in diameter. Most objects smaller than 10 centimeters go untracked! As the orbital debris population grows, the risk to other orbiting objects, most importantly manned space vehicles, of a collision with a piece of debris also grows. The kinetic energy of a solid 1 cm aluminum sphere traveling at an orbital velocity of 10 km/sec is equivalent to a 400 lb. safe traveling at 60 mph. Fortunately, the volume of space in which the orbiting population resides is large, collisions are infrequent, but they do occur. The Space Shuttle often returns to earth with its windshield pocked with small pits or craters caused by collisions with very small, sub-millimeter-size pieces of debris (paint flakes, particles from solid rocket exhaust, etc.), and micrometeoroids. To get a more complete picture of the orbital-debris environment, NASA has been using both radar and optical techniques to monitor the orbital debris environment. This paper gives an overview of the orbital debris environment and NASA's measurement program.

  20. Business innovation symposium ‘At what price? IP-related thoughts on new business models for space information’

    Science.gov (United States)

    Smith, Lesley Jane

    2011-09-01

    Spatial data and imagery generators are set to become tomorrow's key players in the information society. This is why satellite owners and operators are examining new revenue-producing models for developing space-related products and services. The use and availability of broadband internet width and satellite data-based services will continue to increase in the future. With the capacity to deliver real time precision downstream data, space agencies and the satellite industry can respond to the demand for high resolution digital space information which, with the appropriate technology, can be integrated into a variety of web-based applications. At a time when the traditional roles of space agencies are becoming more hybrid, largely as a result of the greater drive towards commercial markets, new value-added markets for space-related information products are continuing to attract attention. This paper discusses whether traditional data policies on space data access and IP licensing schemes stand to remain the feasible prototype for distributing and marketing space data, and how this growth market might benefit from looking at an 'up and running' global IP management system already operating to manage end user digital demand. PrefaceThe terminology describing the various types of spatial data and space-based information is not uniformly used within the various principles, laws and policies that govern space data. For convenience only this paper refers to primary or raw data gathered by the space-based industry as spatial or raw data, and the data as processed and sold on or distributed by ground-based companies as space information products and services. In practise, spatial data range from generic to specific data sets, digital topography, through to pictures and imagery services at various resolutions, with 3-D perspectives underway. The paper addresses general IP considerations relating to spatial data, with some reference to remote sensing itself. Exact IP details

  1. Symposium Summary

    Science.gov (United States)

    Levesque, Emily M.

    2017-11-01

    This proceeding summarizes the highlights of IAU 329, ``The Lives and Death-Throes of Massive Stars'', held in Auckland, NZ from 28 Nov - 2 Dec. I consider the progress that has been made in the field over the course of these ``beach symposia'', outline the overall content of the conference, and discuss how the current subfields in massive stellar astrophysics have evolved in recent years. I summarize some of the new results and innovative approaches that were presented during the symposium, and conclude with a discussion of how current and future resources in astronomy can serve as valuable tools for studying massive stars in the coming years.

  2. IUTAM Symposium

    CERN Document Server

    Pedley, Timothy

    2003-01-01

    The IUTAM Symposium on Flow in Collapsible Tubes and Past Other Highly Compliant Boundaries was held on 26-30 March, 2001, at the University of Warwick. As this was the first scientific meeting of its kind we considered it important to mark the occasion by producing a book. Accordingly, at the end of the Symposium the Scientific Committee met to discuss the most appropriate format for the book. We wished to avoid the format of the conventional conference book consisting of a large number of short articles of varying quality. It was agreed that instead we should produce a limited number of rigorously refereed and edited articles by selected participants who would aim to sum up the state of the art in their particular research area. The outcome is the present book. Peter W. Ca rpenter, Warwick Timothy J. Pedley, Cambridge May, 2002. VB SCIENTIFIC COMMITTEE Co-Chair: P.W. Carpenter, Engineering, Warwiek, UK Co-Chair: TJ. Pedley, DAMTP, Cambridge, UK V.V. Babenko, Hydromechanics, Kiev, Ukraine R. Bannasch, Bionik...

  3. Introduction: Re-Igniting Critical Race In Canadian Legal Spaces: Introduction To The Special Symposium Issue Of Contemporary Accounts Of Racialization In Canada

    Directory of Open Access Journals (Sweden)

    Shanthi Senthe

    2013-10-01

    Full Text Available Osgoode Hall Law School, York University’s Challenging Conventions! Speaker Series organized Re-Igniting Critical Race: A Symposium on Contemporary Accounts of Racialization in Canada on November 2, 2012.  The symposium sought to explore critical race theory and its praxis within the Canadian legal academy by inviting emerging scholars and practitioners to engage with the scholarship of Professor Patricia Williams.

  4. Problems of Small Debris

    Directory of Open Access Journals (Sweden)

    V. V. Zelentsov

    2015-01-01

    Full Text Available During the exploration of outer space (as of 1/1 2011 6853 was launched spacecraft (SC are successful 6264, representing 95% of the total number of starts. The most intensively exploited space Russia (USSR (3701 starts, 94% successful, USA (2774 starts, 90% successful, China (234 starts, 96% successful and India (89 starts, 90% successful. A small part of running the spacecraft returned to Earth (manned spacecraft and transport, and the rest remained in orbit. Some of them are descended from orbit and burned up in the atmosphere, the rest remained in the OCP and turned into space debris (SD.The composition of the Cabinet is diverse: finish the job spacecraft; boosters and the last stage of launch vehicles left in orbit after SC injection; technological waste arising during the opening drop-down structures and fragments of the destroyed spacecraft. The resulting explosion orbital SD forms ellipsoidal region which orbits blasted object. Then, as a result of precession, is the distribution of objects in orbit explosion exploding spacecraft.The whole Cabinet is divided into two factions: the observed (larger than 100 mm and not observed (less than 100 mm. Observed debris katalogalizirovan and 0.2% of the total number of SD, there was no SD is the bulk - 99.8%.SC meeting working with a fragment observed SD predictable and due to changes in altitude spacecraft avoids a possible meeting. Contact spacecraft with large fragment lead to disaster (which took place at a meeting of the Russian communications satellite "Cosmos-2251" and the American machine "Iridium". Meeting with small SD is not predictable, especially if it was formed by an explosion or collision fragments together. Orbit that KM is not predictable, and the speed can be up to 10 km / s. Meeting with small particle SD no less dangerous for the spacecraft. The impact speed of spacecraft with space debris particles can reach up to 10 ... 15 km / s at such speeds the breakdown probability thin

  5. International Pacific Air and Space Technology Conference and Aircraft Symposium, 29th, Gifu, Japan, Oct. 7-11, 1991, Proceedings

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Various papers on air and space technology are presented. Individual topics addressed include: media selection analysis: implications for training design, high-speed challenge for rotary wing aircraft, high-speed VSTOL answer to congestion, next generation in computational aerodynamics, acrobatic airship 'Acrostat', ducted fan VTOL for working platform, Arianespace launch of Lightsats, small particle acceleration by minirailgun, free-wake analyses of a hovering rotor using panel method, update of the X-29 high-angle-of-attack program, economic approach to accurate wing design, flow field around thick delta wing with rounded leading edge, aerostructural integrated design of forward-swept wing, static characteristics of a two-phase fluid drop system, simplfied-model approach to group combustion of fuel spray, avionics flight systems for the 21st century. Also discussed are: Aircraft Command in Emergency Situations, spectrogram diagnosis of aircraft disasters, shock interaction induced by two hemisphere-cylinders, impact response of composite UHB propeller blades, high-altitude lighter-than-air powered platform, integrated wiring system, auxiliary power units for current and future aircraft, Space Shuttle Orbiter Auxiliary Power Unit status, numerical analysis of RCS jet in hypersonic flights, energy requirements for the space frontier, electrical system options for space exploration, aerospace plane hydrogen scramjet boosting, manual control of vehicles with time-varying dynamics, design of strongly stabilizing controller, development of the Liquid Apogee Propulsion System for ETS-VI

  6. International Pacific Air and Space Technology Conference and Aircraft Symposium, 29th, Gifu, Japan, Oct. 7-11, 1991, Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    Various papers on air and space technology are presented. Individual topics addressed include: media selection analysis: implications for training design, high-speed challenge for rotary wing aircraft, high-speed VSTOL answer to congestion, next generation in computational aerodynamics, acrobatic airship 'Acrostat', ducted fan VTOL for working platform, Arianespace launch of Lightsats, small particle acceleration by minirailgun, free-wake analyses of a hovering rotor using panel method, update of the X-29 high-angle-of-attack program, economic approach to accurate wing design, flow field around thick delta wing with rounded leading edge, aerostructural integrated design of forward-swept wing, static characteristics of a two-phase fluid drop system, simplfied-model approach to group combustion of fuel spray, avionics flight systems for the 21st century. Also discussed are: Aircraft Command in Emergency Situations, spectrogram diagnosis of aircraft disasters, shock interaction induced by two hemisphere-cylinders, impact response of composite UHB propeller blades, high-altitude lighter-than-air powered platform, integrated wiring system, auxiliary power units for current and future aircraft, Space Shuttle Orbiter Auxiliary Power Unit status, numerical analysis of RCS jet in hypersonic flights, energy requirements for the space frontier, electrical system options for space exploration, aerospace plane hydrogen scramjet boosting, manual control of vehicles with time-varying dynamics, design of strongly stabilizing controller, development of the Liquid Apogee Propulsion System for ETS-VI.

  7. IUTAM Symposium

    CERN Document Server

    Bui, Huy

    1993-01-01

    Inverse problems occur in a wide variey of fields. In general, the inverse problem can be defined as one where one should estimate the cause from the result, while the direct problem is concerned with how to obtain the result from the cause. The aim of this symposium was to gather scientists and researchers in engineering mechanics concerned with inverse problems in order to exchange research result and develop computational and experimentalapproaches to solve inverse problems. The contributions in this volume cover the following subjects: mathematical and computational aspects of inverse problems, parameter or system identification, shape determination, sensitivity analysis, optimization, material property characterization, ultrasonic nondestructive testing, elastodynamic inverse problems, thermal inverse problems, and other miscellaneous engineering applications.

  8. SPPEXA Symposium

    CERN Document Server

    Neumann, Philipp; Nagel, Wolfgang

    2016-01-01

    The research and its outcomes presented in this collection focus on various aspects of high-performance computing (HPC) software and its development which is confronted with various challenges as today's supercomputer technology heads towards exascale computing. The individual chapters address one or more of the research directions (1) computational algorithms, (2) system software, (3) application software, (4) data management and exploration, (5) programming, and (6) software tools. The collection thereby highlights pioneering research findings as well as innovative concepts in exascale software development that have been conducted under the umbrella of the priority programme "Software for Exascale Computing" (SPPEXA) of the German Research Foundation (DFG) and that have been presented at the SPPEXA Symposium, Jan 25-27 2016, in Munich. The book has an interdisciplinary appeal: scholars from computational sub-fields in computer science, mathematics, physics, or engineering will find it of particular interest...

  9. Apparatus for controlling nuclear core debris

    International Nuclear Information System (INIS)

    Jones, R.D.

    1978-01-01

    Disclosed is an apparatus for containing, cooling, and dispersing reactor debris assumed to flow from the core area in the unlikely event of an accident causing core meltdown. The apparatus includes a plurality of horizontally disposed vertically spaced plates, having depressions to contain debris in controlled amounts, and a plurality of holes therein which provide natural circulation cooling and a path for debris to continue flowing downward to the plate beneath. The uppermost plates may also include generally vertical sections which form annular-like flow areas which assist the natural circulation cooling

  10. Apparatus for controlling nuclear core debris

    Science.gov (United States)

    Jones, Robert D.

    1978-01-01

    Nuclear reactor apparatus for containing, cooling, and dispersing reactor debris assumed to flow from the core area in the unlikely event of an accident causing core meltdown. The apparatus includes a plurality of horizontally disposed vertically spaced plates, having depressions to contain debris in controlled amounts, and a plurality of holes therein which provide natural circulation cooling and a path for debris to continue flowing downward to the plate beneath. The uppermost plates may also include generally vertical sections which form annular-like flow areas which assist the natural circulation cooling.

  11. Algorithms for the Computation of Debris Risk

    Science.gov (United States)

    Matney, Mark J.

    2017-01-01

    Determining the risks from space debris involve a number of statistical calculations. These calculations inevitably involve assumptions about geometry - including the physical geometry of orbits and the geometry of satellites. A number of tools have been developed in NASA’s Orbital Debris Program Office to handle these calculations; many of which have never been published before. These include algorithms that are used in NASA’s Orbital Debris Engineering Model ORDEM 3.0, as well as other tools useful for computing orbital collision rates and ground casualty risks. This paper presents an introduction to these algorithms and the assumptions upon which they are based.

  12. Algorithms for the Computation of Debris Risks

    Science.gov (United States)

    Matney, Mark

    2017-01-01

    Determining the risks from space debris involve a number of statistical calculations. These calculations inevitably involve assumptions about geometry - including the physical geometry of orbits and the geometry of non-spherical satellites. A number of tools have been developed in NASA's Orbital Debris Program Office to handle these calculations; many of which have never been published before. These include algorithms that are used in NASA's Orbital Debris Engineering Model ORDEM 3.0, as well as other tools useful for computing orbital collision rates and ground casualty risks. This paper will present an introduction to these algorithms and the assumptions upon which they are based.

  13. Seventh International Beaver Symposium

    OpenAIRE

    Yuri A. Gorshkov

    2016-01-01

    The paper presents data on the seventh international Beaver Symposium. Brief historical background about previous Beaver Symposia beaver is shown. Data on the sections of symposium, number of participants and reports are presented.

  14. Seventh International Beaver Symposium

    Directory of Open Access Journals (Sweden)

    Yuri A. Gorshkov

    2016-05-01

    Full Text Available The paper presents data on the seventh international Beaver Symposium. Brief historical background about previous Beaver Symposia beaver is shown. Data on the sections of symposium, number of participants and reports are presented.

  15. Laser Remediation of Threats Posed by Small Orbital Debris

    Science.gov (United States)

    Fork, Richard L.; Rogers, Jan R.; Hovater, Mary A.

    2012-01-01

    The continually increasing amount of orbital debris in near Earth space poses an increasing challenge to space situational awareness. Recent collisions of spacecraft caused abrupt increases in the density of both large and small debris in near Earth space. An especially challenging class of threats is that due to the increasing density of small (1 mm to 10 cm dimension) orbital debris. This small debris poses a serious threat since: (1) The high velocity enables even millimeter dimension debris to cause serious damage to vulnerable areas of space assets, e.g., detector windows; (2) The small size and large number of debris elements prevent adequate detection and cataloguing. We have identified solutions to this threat in the form of novel laser systems and novel ways of using these laser systems. While implementation of the solutions we identify is challenging we find approaches offering threat mitigation within time frames and at costs of practical interest. We base our analysis on the unique combination of coherent light specifically structured in both space and time and applied in novel ways entirely within the vacuum of space to deorbiting small debris. We compare and contrast laser based small debris removal strategies using ground based laser systems with strategies using space based laser systems. We find laser systems located and used entirely within space offer essential and decisive advantages over groundbased laser systems.

  16. Symposium 3 of JENAM 2011

    CERN Document Server

    Georgieva, Katya; Nagovitsyn, Yury; The sun : new challenges

    2012-01-01

    These are the proceedings of the Symposium 3 of JENAM 2011 on new scientific challenges posed by the Sun. The topics covered are   1. The unusual sunspot minimum, which poses challenges to the solar dynamo theory 2. The Sun’s Terra-Hertz emission, which opens a new observational window 3. Corona wave activity 4. Space weather agents - initiation, propagation, and forecasting In 21 in-depth contributions, the reader will be presented with the latest findings.

  17. Space science comes of age: Perspectives in the history of the space sciences Proceedings of the Symposium, Washington, DC, March 23, 24, 1981

    International Nuclear Information System (INIS)

    Hanle, P.A.; Chamberlain, V.D.

    1981-01-01

    The development of space science is recounted in two parts, the first written by founders and pioneers in the field who recount some of the important scientific discoveries in their areas, the second offering a preliminary view of space science by professional historians. The subjects of the first part are solar physics, rocket astronomy, the ultraviolet spectra of stars, lunar exploration and geology. James Van Allen's lecture first disclosing his discovery of the radiation belts surrounding the earth is reprinted. The second part includes the story of the development of theories about the origin of the solar system before 1960, a discussion of studies of the upper atmosphere, a concise history of space-launch vehicles, and a review of the politics and funding of the Landsat project

  18. Symposium summary

    International Nuclear Information System (INIS)

    Lawford, R.G.; Hubbard, K.G.

    1991-01-01

    For the purposes of the symposium, the Great Plains area was defined as the three Canadian Prairie provinces of Alberta, Saskatchewan and Manitoba, and eight north central states including North and South Dakota, Nebraska, Montana, Minnesota, Wyoming, Colorado and Kansas, covering over 3.5 million square kilometers. The presentations during the plenary sessions provided a comprehensive overview of the climate change subject and uncertainties, and the resource base and socio-economic structure which it will impact. There was a high degree of unanimity concerning research needs, which fell into seven areas: lack of understanding and models of linkages between climate, the resource base, and socio-economic structures; need for better regional climate change scenarios for use in impact studies; inadequate understanding of natural processes, particularly where physical, biophysical and biogeochemical parameters are operating; need for policy research to enable change of policies and informed decisions; readily available common databases for use in joint U.S./Canada climate studies; an information base and mechanisms to enable more effective communications; and networks to monitor the progress of global warming and its impact on resources

  19. Debris thickness patterns on debris-covered glaciers

    Science.gov (United States)

    Anderson, Leif S.; Anderson, Robert S.

    2018-06-01

    Many debris-covered glaciers have broadly similar debris thickness patterns: surface debris thickens and tends to transition from convex- to concave-up-down glacier. We explain this pattern using theory (analytical and numerical models) paired with empirical observations. Down glacier debris thickening results from the conveyor-belt-like nature of the glacier surface in the ablation zone (debris can typically only be added but not removed) and from the inevitable decline in ice surface velocity toward the terminus. Down-glacier thickening of debris leads to the reduction of sub-debris melt and debris emergence toward the terminus. Convex-up debris thickness patterns occur near the up-glacier end of debris covers where debris emergence dominates (ablation controlled). Concave-up debris thickness patterns occur toward glacier termini where declining surface velocities dominate (velocity controlled). A convex-concave debris thickness profile inevitably results from the transition between ablation-control and velocity-control down-glacier. Debris thickness patterns deviating from this longitudinal shape are most likely caused by changes in hillslope debris supply through time. By establishing this expected debris thickness pattern, the effects of climate change on debris cover can be better identified.

  20. Loopy, Floppy and Fragmented: Debris Characteristics Matter

    Science.gov (United States)

    Parrish, J.; Burgess, H. K.

    2016-02-01

    Marine debris is a world-wide problem threatening the health and safety of marine organisms, ecosystems, and humans. Recent and ongoing research shows that risk of harm is not associated with identity, but rather with a set of specific character states, where the character state space intersection is defined by the organism of interest. For example, intersections of material, color, rigidity and size predict the likelihood of an object being ingested: plastic, clear-white, floppy objects risks to sea turtles whereas yellow-red, rigid objects risks to albatrosses. A character state space approach allows prioritization of prevention and removal of marine debris informed by risk assessments for species of interest by comparing species ranges with spatio-temporal hotspots of all debris with characteristics known to be associated with increased risk of harm, regardless of identity. With this in mind, the Coastal Observation and Seabird Survey Team (COASST) developed and tested a 20 character data collection approach to quantifying the diversity and abundance of marine debris found on beaches. Development resulted in meta-analysis of the literature and expert opinion eliciting harmful character state space. Testing included data collection on inter-rater reliability and accuracy, where the latter included 75 participants quantifying marine debris characteristics on monthly surveys of 30 beaches along the Washington and Oregon coastlines over the past year. Pilot work indicates that characters must be simply and operationally defined, states must be listed, and examples must be provided for color states. Complex characters (e.g., windage, shape) are not replicable across multiple data collectors. Although data collection takes longer than other marine debris surveys for a given amount of debris and area surveyed, volunteer rapidity and accuracy improved within 3-5 surveys. Initial feedback indicated that volunteers were willing to continue collecting data as long as they

  1. The fast debris evolution model

    Science.gov (United States)

    Lewis, H. G.; Swinerd, G. G.; Newland, R. J.; Saunders, A.

    2009-09-01

    . The results demonstrate that the FADE model is able to capture comparable time-series of collisions and number of objects as predicted by DAMAGE in several scenarios. Further, and perhaps more importantly, its speed and flexibility allows the user to explore and understand the evolution of the space debris environment.

  2. 4th Abel Symposium

    CERN Document Server

    Friedlander, Eric; Jahren, Björn; Østvær, Paul

    2009-01-01

    The 2007 Abel Symposium took place at the University of Oslo in August 2007. The goal of the symposium was to bring together mathematicians whose research efforts have led to recent advances in algebraic geometry, algebraic K-theory, algebraic topology, and mathematical physics. A common theme of this symposium was the development of new perspectives and new constructions with a categorical flavor. As the lectures at the symposium and the papers of this volume demonstrate, these perspectives and constructions have enabled a broadening of vistas, a synergy between once-differentiated subjects, and solutions to mathematical problems both old and new.

  3. LEGACY - EOP Marine Debris

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data contains towed diver surveys of and weights of marine debris removed from the near shore environments of the NWHI.

  4. Zodiac II: Debris Disk Science from a Balloon

    Science.gov (United States)

    Bryden, Geoffrey; Traub, Wesley; Roberts, Lewis C., Jr.; Bruno, Robin; Unwin, Stephen; Backovsky, Stan; Brugarolas, Paul; Chakrabarti, Supriya; Chen, Pin; Hillenbrand, Lynne; hide

    2011-01-01

    Zodiac II is a proposed balloon-borne science investigation of debris disks around nearby stars. Debris disks are analogs of the Asteroid Belt (mainly rocky) and Kuiper Belt (mainly icy) in our Solar System. Zodiac II will measure the size, shape, brightness, and color of a statistically significant sample of disks. These measurements will enable us to probe these fundamental questions: what do debris disks tell us about the evolution of planetary systems; how are debris disks produced; how are debris disks shaped by planets; what materials are debris disks made of; how much dust do debris disks make as they grind down; and how long do debris disks live? In addition, Zodiac II will observe hot, young exoplanets as targets of opportunity. The Zodiac II instrument is a 1.1-m diameter SiC (Silicone carbide) telescope and an imaging coronagraph on a gondola carried by a stratospheric balloon. Its data product is a set of images of each targeted debris disk in four broad visible-wavelength bands. Zodiac II will address its science questions by taking high-resolution, multi-wavelength images of the debris disks around tens of nearby stars. Mid-latitude flights are considered: overnight test flights in the US followed by half-global flights in the Southern Hemisphere. These longer flights are required to fully explore the set of known debris disks accessible only to Zodiac II. On these targets, it will be 100 times more sensitive than the Hubble Space Telescope's Advanced Camera for Surveys (HST/ACS); no existing telescope can match the Zodiac II contrast and resolution performance. A second objective of Zodiac II is to use the near-space environment to raise the Technology Readiness Level (TRL) of SiC mirrors, internal coronagraphs, deformable mirrors, and wavefront sensing and control, all potentially needed for a future space-based telescope for high-contrast exoplanet imaging.

  5. Symposium on neutron scattering

    International Nuclear Information System (INIS)

    Lehmann, M.S.; Saenger, W.; Hildebrandt, G.; Dachs, H.

    1984-01-01

    Extended abstracts of the named symposium are presented. The first part of this report contains the abstracts of the lectures, the second those of the posters. Topics discussed on the symposium include neutron diffraction and neutron scattering studies in magnetism, solid state chemistry and physics, materials research. Some papers discussing instruments and methods are included too. (GSCH)

  6. Simons Symposium

    CERN Document Server

    Hassett, Brendan; Tschinkel, Yuri

    2017-01-01

    Based on the Simons Symposia held in 2015, the proceedings in this volume focus on rational curves on higher-dimensional algebraic varieties and applications of the theory of curves to arithmetic problems. There has been significant progress in this field with major new results, which have given new impetus to the study of rational curves and spaces of rational curves on K3 surfaces and their higher-dimensional generalizations. One main recent insight the book covers is the idea that the geometry of rational curves is tightly coupled to properties of derived categories of sheaves on K3 surfaces. The implementation of this idea led to proofs of long-standing conjectures concerning birational properties of holomorphic symplectic varieties, which in turn should yield new theorems in arithmetic. This proceedings volume covers these new insights in detail. .

  7. Comparison of debris environment models (MASTER-2005, 2001, ORDEM2000): For international standardization of process based implementation of meteoroid and debris environmental models

    OpenAIRE

    Fukushige, Shinya; Akahoshi, Yasuhiro; Kitazawa, Yukihito; Goka, Tateo; 福重 進也; 赤星 保浩; 北澤 幸人; 五家 建夫

    2007-01-01

    Space agencies of some countries have space debris environment model for design of spacecrafts. These models can estimate debris flux as a function of the size, relative impact velocity, and impact angle in a spacecraft orbit. However, it is known calculation results of models are not always consistent with each other. Therefore, international common implementation process of debris environment model is required. In this paper, as the first step of international standardization of implementat...

  8. New advances for modelling the debris avalanches

    Science.gov (United States)

    Cuomo, Sabatino; Cascini, Leonardo; Pastor, Manuel; Castorino, Giuseppe Claudio

    2013-04-01

    Flow-like landslides are a major global hazard and they occur worldwide causing a large number of casualties, significant structural damages to property and infrastructures as well as economic losses. When involving open slopes, these landslides often occur in triangular source areas where initial slides turn into avalanches through further failures and/or eventual soil entrainment. This paper deals with the numerical modelling of the propagation stage of debris avalanches which provides information such as the propagation pattern of the mobilized material, its velocity, thickness and run-out distance. In the paper, a "depth integrated" model is used which allows: i) adequately taking into account the irregular topography of real slopes which greatly affect the propagation stage and ii) using a less time consuming model than fully 3D approaches. The used model is named "GeoFlow_SPH" and it was formerly applied to theoretical, experimental and real case histories (Pastor et al., 2009; Cascini et al., 2012). In this work the behavior of debris avalanches is analyzed with special emphasis on the apical angle, one of the main features of this type of landslide, in relation to soil rheology, hillslope geometry and features of triggering area. Furthermore, the role of erosion has been investigated with reference to the uppermost parts of open slopes with a different steepness. These analyses are firstly carried out for simplified benchmark slopes, using both water-like materials (with no shear strength) and debris type materials. Then, three important case studies of Campania region (Cervinara, Nocera Inferiore e Sarno) are analyzed where debris avalanches involved pyroclastic soils originated from the eruptive products of Vesusius volcano. The results achieved for both benchmark slopes and real case histories outline the key role played by the erosion on the whole propagation stage of debris avalanches. The results are particularly satisfactory since they indicate the

  9. CONTEXT 2015 Doctorial Symposium

    DEFF Research Database (Denmark)

    Eklund, Peter; wegener, rebekah

    2015-01-01

    What is the CONTEXT 2015 Doctoral Symposium? The CONTEXT 2015 Doctoral Symposium is an opportunity for doctoral researchers to showcase their work and discuss problems, challenges, and ideas in an open and collegial environment with expert feedback. The Doctoral Symposium is a workshop for doctoral...... feedback and general advice in a constructive atmosphere. Doctoral researchers will present and discuss their research in a supportive atmosphere with other doctoral researchers and an international panel of established researchers that provide expert feedback. The workshop will take place on a single full...... day, Monday November 2, 2015, the day prior to the start of the main CONTEXT 2015 conference....

  10. The world state of orbital debris measurements and modeling

    Science.gov (United States)

    Johnson, Nicholas L.

    2004-02-01

    For more than 20 years orbital debris research around the world has been striving to obtain a sharper, more comprehensive picture of the near-Earth artificial satellite environment. Whereas significant progress has been achieved through better organized and funded programs and with the assistance of advancing technologies in both space surveillance sensors and computational capabilities, the potential of measurements and modeling of orbital debris has yet to be realized. Greater emphasis on a systems-level approach to the characterization and projection of the orbital debris environment would prove beneficial. On-going space surveillance activities, primarily from terrestrial-based facilities, are narrowing the uncertainties of the orbital debris population for objects greater than 2 mm in LEO and offer a better understanding of the GEO regime down to 10 cm diameter objects. In situ data collected in LEO is limited to a narrow range of altitudes and should be employed with great care. Orbital debris modeling efforts should place high priority on improving model fidelity, on clearly and completely delineating assumptions and simplifications, and on more thorough sensitivity studies. Most importantly, however, greater communications and cooperation between the measurements and modeling communities are essential for the efficient advancement of the field. The advent of the Inter-Agency Space Debris Coordination Committee (IADC) in 1993 has facilitated this exchange of data and modeling techniques. A joint goal of these communities should be the identification of new sources of orbital debris.

  11. Disaster Debris Recovery Database - Landfills

    Data.gov (United States)

    U.S. Environmental Protection Agency — The US EPA Disaster Debris Recovery Database (DDRD) promotes the proper recovery, recycling, and disposal of disaster debris for emergency responders at the federal,...

  12. Disaster Debris Recovery Database - Recovery

    Data.gov (United States)

    U.S. Environmental Protection Agency — The US EPA Disaster Debris Recovery Database (DDRD) promotes the proper recovery, recycling, and disposal of disaster debris for emergency responders at the federal,...

  13. XXth symposium neuroradiologicum 2014

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-09-15

    The volume includes abstracts from lectures and poster presentations during the XXth symposium neuroradiologicum 2014 covering the following issues: Stroke, head and neck, pediatric diagnostic neuroradiology, spine and interventional neuroradiology, adult diagnostic neuroradiology, intravascular interventional neuroradiology.

  14. COST 516 Tribology Symposium

    Energy Technology Data Exchange (ETDEWEB)

    Ronkainen, H.; Holmberg, K. [eds.

    1998-11-01

    Cost 516 Tribology action is the first joint European research action focusing on tribology, which originates in the approval of its Memorandum of understanding in February 1994. The COST 516 Tribology Symposium took place in Espoo, Finland from 14th to 15th May 1998. This was the first Symposium of the COST 516 Tribology action. The large number of research contributions at the Symposium, altogether almost SO, and their scientific and technical level, is an indication of the importance and significance of tribology research. The symposium proceedings contain papers in a wide variety of subjects, covering the three categories of the COST 516 Tribology action, namely Grease lubrication (GRIT), Tribology of renewable environmentally adapted lubricants (REAL) and Coatings and surface treatments (CAST). (orig.)

  15. Optimizing of the recycling of contaminated concrete debris. Final report

    International Nuclear Information System (INIS)

    Kloeckner, J.; Rasch, H.; Schloesser, K.H.; Schon, T.

    1999-01-01

    1. Latest research: So far concrete debris from nuclear facilities has been free released or was treated as radioactive waste. 2. Objective: The objective of this study is to develop solutions and methods for recycling concrete debris. The amount of materials used in nuclear facilities should be limited and the contamination of new materials should be avoided. 3. Methods: The status of recycling was presented using examples of operating or completed decommissioning as well as available studies and literature. The quality requirements for the production of new concrete products using recycled materials has been discussed. The expected amounts of concrete debris for the next 12 years was estimated. For the proposed recycling examples, radiological and economic aspects have been considered. 4. Results: The production of qualified concrete products from concrete debris is possible by using modified receptions. Technical regulations to this are missing. There is no need for the utilization of large amounts of concrete debris for shielding walls. For the production of new shielding-containers for radioactive waste, concrete debris can be applied. Regarding the distance to a central recycling facility the use of mobile equipment can be economical. By using the concrete for filling the cavity or space in a final storage, it is possible to dispose the whole radioactive debris. 5. Application possibilities: The use of concrete debris as an inner concrete shielding in waste-containers today is already possible. For the manufacture of qualified concrete products by using recycling products, further developments and regulations are necessary. (orig.) [de

  16. Space information systems in the Space Station era; Proceedings of the AIAA/NASA International Symposium on Space Information Systems, Washington, DC and Greenbelt, MD, June 22, 23, 1987

    Science.gov (United States)

    Gerard, Mireille (Editor); Edwards, Pamela W. (Editor)

    1988-01-01

    Technological and planning issues for data management, processing, and communication on Space Station Freedom are discussed in reviews and reports by U.S., European, and Japanese experts. The space-information-system strategies of NASA, ESA, and NASDA are discussed; customer needs are analyzed; and particular attention is given to communication and data systems, standards and protocols, integrated system architectures, software and automation, and plans and approaches being developed on the basis of experience from past programs. Also included are the reports from workshop sessions on design to meet customer needs, the accommodation of growth and new technologies, and system interoperability.

  17. Humans and machines in space: The vision, the challenge, the payoff; Proceedings of the 29th Goddard Memorial Symposium, Washington, Mar. 14, 15, 1991

    Science.gov (United States)

    Johnson, Bradley; May, Gayle L.; Korn, Paula

    The present conference discusses the currently envisioned goals of human-machine systems in spacecraft environments, prospects for human exploration of the solar system, and plausible methods for meeting human needs in space. Also discussed are the problems of human-machine interaction in long-duration space flights, remote medical systems for space exploration, the use of virtual reality for planetary exploration, the alliance between U.S. Antarctic and space programs, and the economic and educational impacts of the U.S. space program.

  18. GEO Debris and Interplanetary Dust: Fluxes and Charging Behavior

    Science.gov (United States)

    Graps, A. L.; Green, S. F.; McBride, N. M.; McDonnell, J. A. M.; Drolshagen, G.; Svedhem, H.; Bunte, K. D.

    2005-08-01

    A population of cosmic dust mixed with a population of man-made debris exists within the Earth's magnetosphere. Measurements of these provide the data samples for studies of the interplanetary dust particles that travel through our magnetosphere from the outside and for studies of the local byproducts of our space endeavours. Even though instruments to detect natural meteoroids and space debris particles have been flown in Low Earth Orbits (LEO) and on interplanetary missions, very little information on the particle environment for Earth orbits above about 600 km altitude have been available. In particular, knowledge about particles smaller than 1 m in the geostationary (GEO) region was largely unknown before GORID. In September 1996, a dust/debris detector: GORID was launched into GEO as a piggyback instrument on the Russian Express-2 telecommunications spacecraft. The instrument began its normal operation in April 1997 and ended its mission in July 2002. The goal of this work was to use GORID's particle data to identify and separate the space debris from the interplanetary dust particles (IDPs) in GEO, to more finely determine the instrument's measurement characteristics and to derive impact fluxes. Here we present some results of that study. We give GORID flux distributions for debris and IDPs and then present intriguing debris clustering features that might be the result of electrostatic fragmentation of the rocket slag particles.

  19. Abel Symposium 2015

    CERN Document Server

    Larsen, Nadia; Neshveyev, Sergey; Skau, Christian

    2016-01-01

    Like the first Abel Symposium, held in 2004, the Abel Symposium 2015 focused on operator algebras. It is interesting to see the remarkable advances that have been made in operator algebras over these years, which strikingly illustrate the vitality of the field. A total of 26 talks were given at the symposium on a variety of themes, all highlighting the richness of the subject. The field of operator algebras was created in the 1930s and was motivated by problems of quantum mechanics. It has subsequently developed well beyond its initial intended realm of applications and expanded into such diverse areas of mathematics as representation theory, dynamical systems, differential geometry, number theory and quantum algebra. One branch, known as “noncommutative geometry”, has become a powerful tool for studying phenomena that are beyond the reach of classical analysis. This volume includes research papers that present new results, surveys that discuss the development of a specific line of research, and articles ...

  20. Orbital Debris: Past, Present, and Future

    Science.gov (United States)

    Stansbery, Gene; Johnson, Nicholas

    2013-01-01

    In the early days of spaceflight, the gBig Sky h theory was the near universally accepted paradigm for dealing with collisions of orbiting objects. This theory was also used during the early years of the aviation industry. Just as it did in aviation, the gBig Sky h theory breaks down as more and more objects accumulate in the environment. Fortunately, by the late 1970 fs some visionaries in NASA and the US Department of Defense (DoD) realized that trends in the orbital environment would inevitably lead to increased risks to operational spacecraft from collisions with other orbiting objects. The NASA Orbital Debris Program was established at and has been conducted at Johnson Space Center since 1979. At the start of 1979, fewer than 5000 objects were being tracked by the US Space Surveillance Network and very few attempts had been made to sample the environment for smaller sizes. Today, the number of tracked objects has quadrupled. Ground ]based and in situ measurements have statistically sampled the LEO environment over most sizes and mitigation guidelines and requirements are common among most space faring nations. NASA has been a leader, not only in defining the debris environment, but in promoting awareness of the issues in the US and internationally, and in providing leadership in developing policies to address the issue. This paper will discuss in broad terms the evolution of the NASA debris program from its beginnings to its present broad range of debris related research. The paper will discuss in some detail current research topics and will attempt to predict future research trends.

  1. The Abel Symposium 2013

    CERN Document Server

    Irgens, Marius; Wold, Erlend

    2015-01-01

    This book focuses on complex geometry and covers highly active topics centered around geometric problems in several complex variables and complex dynamics, written by some of the world’s leading experts in their respective fields. This book features research and expository contributions from the 2013 Abel Symposium, held at the Norwegian University of Science and Technology Trondheim on July 2-5, 2013. The purpose of the symposium was to present the state of the art on the topics, and to discuss future research directions.

  2. Persistent marine debris

    International Nuclear Information System (INIS)

    Levy, E.M.

    1992-01-01

    In this paper the distribution of persistent marine debris, adrift on world oceans and stranded on beaches globally, is reviewed and related to the known inputs and transport by the major surface currents. Since naturally occurring processes eventually degrade petroleum in the environment, international measures to reduce the inputs have been largely successful in alleviating oil pollution on a global, if not on a local, scale. Many plastics, however, are so resistant to natural degradation that merely controlling inputs will be insufficient, and more drastic and costly measures will be needed to cope with the emerging global problem posed by these materials

  3. Technology Combination Analysis Tool (TCAT) for Active Debris Removal

    Science.gov (United States)

    Chamot, B.; Richard, M.; Salmon, T.; Pisseloup, A.; Cougnet, C.; Axthelm, R.; Saunder, C.; Dupont, C.; Lequette, L.

    2013-08-01

    This paper present the work of the Swiss Space Center EPFL within the CNES-funded OTV-2 study. In order to find the most performant Active Debris Removal (ADR) mission architectures and technologies, a tool was developed in order to design and compare ADR spacecraft, and to plan ADR campaigns to remove large debris. Two types of architectures are considered to be efficient: the Chaser (single-debris spacecraft), the Mothership/ Kits (multiple-debris spacecraft). Both are able to perform controlled re-entry. The tool includes modules to optimise the launch dates and the order of capture, to design missions and spacecraft, and to select launch vehicles. The propulsion, power and structure subsystems are sized by the tool thanks to high-level parametric models whilst the other ones are defined by their mass and power consumption. Final results are still under investigation by the consortium but two concrete examples of the tool's outputs are presented in the paper.

  4. Birch symposium proceedings

    Science.gov (United States)

    W.T. Doolittle; P.E. Bruns

    1969-01-01

    This symposium on yellow and paper birch is the third in a series of meetings devoted to discussion of our fine hardwood timber species. The first meeting, held at Carbondale, Illinois, in 1966, dealt with black walnut. The second, held at Houghton, Michigan, in 1968, dealt with sugar maple. The purpose of this third meeting is to bring together our present knowledge...

  5. Symposium summary and prognosis

    International Nuclear Information System (INIS)

    Bjorken, J.D.

    1975-11-01

    The summary of the symposium on high energy physics experiments includes phenomena at low energies, the foundations of physics (considered to be mainly gravitation and quantum electrodynamics), standards of reference used for interpretation of experimental data, the new physics, particle proliferation, theoretical development, and a prognosis for the future

  6. European Cosmic Ray Symposium

    CERN Multimedia

    Pattison,B

    1992-01-01

    13me Symposium qui se déroule du 27 au 31 juillet pour la première fois au Cern. Brian Pattison ouvre la cérémonie et donne la parole à Dr.Ugland (qui représente le DG C.Rubbia excusé) et d'autres intervenants

  7. Issues of HRD. Symposium.

    Science.gov (United States)

    2002

    This document contains three papers from a symposium on issues of human resource development (HRD). "The Complex Roots of Human Resource Development" (Monica Lee) discusses the roots of HRD within the framework of the following views of management: (1) classic (the view that managers must be able to create appropriate rules and…

  8. Debris Dispersion Model Using Java 3D

    Science.gov (United States)

    Thirumalainambi, Rajkumar; Bardina, Jorge

    2004-01-01

    This paper describes web based simulation of Shuttle launch operations and debris dispersion. Java 3D graphics provides geometric and visual content with suitable mathematical model and behaviors of Shuttle launch. Because the model is so heterogeneous and interrelated with various factors, 3D graphics combined with physical models provides mechanisms to understand the complexity of launch and range operations. The main focus in the modeling and simulation covers orbital dynamics and range safety. Range safety areas include destruct limit lines, telemetry and tracking and population risk near range. If there is an explosion of Shuttle during launch, debris dispersion is explained. The shuttle launch and range operations in this paper are discussed based on the operations from Kennedy Space Center, Florida, USA.

  9. International symposium 'Energetics 2006'. Symposium proceedings

    International Nuclear Information System (INIS)

    2006-01-01

    ZEMAK as a civil association, created in the term positive legitimate regulations of our country, presents non party, non political and non profitable association, which primary goal is animation of eperts and other scientific and non scientific workers in the function of permanent following, studying and giving directives for solve the energy problems for a long temporal period. Behind us are fourteen successful years of fertile and wealthy work, which is bringing maimal penetration in domestic as well as foreign scientific field. This successful work of ZEMAK deserves by all members which professional work is in the institutions like: MANU (Macedonian academy of science and art), Technical faculties from the Universities, state and private company from energy field and other civil persons. The main goal of this 9-th International Symposium traditionally is to collect all engineers and eperts from the field of energy, and those which professional life is energy. During this International Symposium will be present, analyze and discuss about 100 incoming papers, prepared by 100th or more authors and coauthors, divided in the following topics: Basic energy and ecology, Renewable energy sources, Energy efficiency and energy saving and Management in energy and regulations.

  10. i-SAIRAS '90; Proceedings of the International Symposium on Artificial Intelligence, Robotics and Automation in Space, Kobe, Japan, Nov. 18-20, 1990

    Science.gov (United States)

    1990-01-01

    The present conference on artificial intelligence (AI), robotics, and automation in space encompasses robot systems, lunar and planetary robots, advanced processing, expert systems, knowledge bases, issues of operation and management, manipulator control, and on-orbit service. Specific issues addressed include fundamental research in AI at NASA, the FTS dexterous telerobot, a target-capture experiment by a free-flying robot, the NASA Planetary Rover Program, the Katydid system for compiling KEE applications to Ada, and speech recognition for robots. Also addressed are a knowledge base for real-time diagnosis, a pilot-in-the-loop simulation of an orbital docking maneuver, intelligent perturbation algorithms for space scheduling optimization, a fuzzy control method for a space manipulator system, hyperredundant manipulator applications, robotic servicing of EOS instruments, and a summary of astronaut inputs on automation and robotics for the Space Station Freedom.

  11. Fourth Tennessee water resources symposium

    International Nuclear Information System (INIS)

    Sale, M.J.; Presley, P.M.

    1991-01-01

    The annual Tennessee Water Resources Symposium was initiated in 1988 as a means to bring together people with common interests in the state's important water-related resources at a technical, professional level. Initially the symposium was sponsored by the American Institute of Hydrology and called the Hydrology Symposium, but the Tennessee Section of the American Water Resources Association (AWRA) has taken on the primary coordination role for the symposium over the last two years and the symposium name was changed in 1990 to water resources to emphasize a more inter-disciplinary theme. This year's symposium carries on the successful tradition of the last three years. Our goal is to promote communication and cooperation among Tennessee's water resources professionals: scientists, engineers, and researchers from federal, state, academic, and private institutions and organizations who have interests and responsibilities for the state's water resources. For these conference proceedings, individual papers are processed separately for the Energy Data Base

  12. Lower end fitting debris collector and end cap spacer grid

    International Nuclear Information System (INIS)

    Bryan, W.J.

    1990-01-01

    This patent describes a nuclear reactor having fuel assemblies including an upper end fitting and spaced nuclear fuel rod spacer grids for supporting and spacing a plurality of elongated nuclear fuel rods. Each includes a hollow active portion of nuclear fuel filled cladding intermediate the rod ends and tapering end cap of solid material with a circumferential groove on the rod end which first encounters reactor coolant flow, a lower end filtering debris collector and end cap spacer grid for capturing and retaining deleterious debris carried by reactor coolant before it enters the active region of a fuel assembly and creates fuel rod cladding damage

  13. Characteristics of Human Body Sensoring towards Electromagnetic Waves in Space (Papers Presented at the International Symposium on Safety Control and Risk Management, SCRM)

    OpenAIRE

    Fujiwara, Shizuo; 藤原, 鎮男

    1989-01-01

    Human body works as a kind of tuning filter for the electromagnetic waves in space. The work can be interpretted in terms of the modelling of the surface of the human body as an equivalent circuit formed of the electronic components of inductance, capacit

  14. Proceedings of the thirtieth national symposium on plasma science and technology: book of abstracts

    International Nuclear Information System (INIS)

    2015-01-01

    The topics covered in this symposium are: basic plasma, nuclear fusion, industrial plasma/plasma processing, space plasma and astrophysical plasma, laser plasma, exotic plasma, plasma diagnostics, computer modeling and other areas. Papers relevant to INIS are indexed separately

  15. COMPUTING: International symposium

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    Recent Developments in Computing, Processor, and Software Research for High Energy Physics, a four-day international symposium, was held in Guanajuato, Mexico, from 8-11 May, with 112 attendees from nine countries. The symposium was the third in a series of meetings exploring activities in leading-edge computing technology in both processor and software research and their effects on high energy physics. Topics covered included fixed-target on- and off-line reconstruction processors; lattice gauge and general theoretical processors and computing; multiprocessor projects; electron-positron collider on- and offline reconstruction processors; state-of-the-art in university computer science and industry; software research; accelerator processors; and proton-antiproton collider on and off-line reconstruction processors

  16. International RILEM Symposium

    CERN Document Server

    Birgisson, Björn; Frost, David; Wang, Linbing

    2013-01-01

    The micro- and nano-modification of infrastructure materials and the associated multi-scale characterization and simulation has the potential to open up whole new uses and classes of materials, with wide-ranging implications for society. The use of multi-scale characterization and simulation brings the ability to target changes at the very small scale that predictably effect the bulk behavior of the material and thus allowing for the optimization of material behavior and performance.   The International RILEM Symposium on Multi-Scale Modeling and Characterization of Infrastructure Materials (Stockholm, June 10-12, 2013) brought together key researchers from around the world to present their findings and ongoing research in this field in a focused environment with extended discussion times. From asphalt to concrete, from chemistry to mechanics, from nano- to macro-scale: the collection of topics covered by the Symposium represents the width and depth of the currently ongoing efforts of developing more sustain...

  17. Symposium 2 of JENAM

    CERN Document Server

    Pasquali, Anna; Environment and the Formation of Galaxies : 30 years later

    2011-01-01

    The publication of the morphology - density relation by Alan Dressler in 1980 brought into the limelight the role played by environment in the formation and evolution of galaxies. The symposium Environment and the Formation of Galaxies: 30 years later, was organised with the purpose of establishing the environmental impact on the evolution of galaxies and its dependence on look-back time. Special emphasis was placed on the physical mechanisms that are responsible for transforming galaxies once they are accreted by a group or a cluster, including the observable imprint left in the galaxy HI distribution. Other major topics of the symposium were the environmental dependence of galaxy properties at z ≥ 1 and the implementation of environmental effects in cosmological models of galaxy formation and evolution. This book presents the edited proceedings of this stimulating meeting.

  18. AIAA/NASA International Symposium on Space Information Systems, 2nd, Pasadena, CA, Sept. 17-19, 1990, Proceedings. Vols. 1 & 2

    Science.gov (United States)

    Tavenner, Leslie A. (Editor)

    1991-01-01

    These proceedings overview major space information system projects and lessons learned from current missions. Other topics include the science information system requirements for the 1990s, an information systems design approach for major programs, the technology needs and projections, the standards for space data information systems, the artificial intelligence technology and applications, international interoperability, and spacecraft data systems and architectures advanced communications. Other topics include the software engineering technology and applications, the multimission multidiscipline information system architectures, the distributed planning and scheduling systems and operations, and the computer and information systems architectures. Paper presented include prospects for scientific data analysis systems for solar-terrestrial physics in the 1990s, the Columbus data management system, data storage technologies for the future, the German aerospace research establishment, and launching artificial intelligence in NASA ground systems.

  19. SYMPOSIUM: Rare decays

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1989-04-15

    Late last year, a symposium entitled 'Rare Decays' attracted 115 participants to a hotel in Vancouver, Canada. These participants were particle physicists interested in checking conventional selection rules to look for clues of possible new behaviour outside today's accepted 'Standard Model'. For physicists, 'rare decays' include processes that have so far not been seen, explicitly forbidden by the rules of the Standard Model, or processes highly suppressed because the decay is dominated by an easier route, or includes processes resulting from multiple transitions.

  20. 1979 DOE statistical symposium

    Energy Technology Data Exchange (ETDEWEB)

    Gardiner, D.A.; Truett T. (comps. and eds.)

    1980-09-01

    The 1979 DOE Statistical Symposium was the fifth in the series of annual symposia designed to bring together statisticians and other interested parties who are actively engaged in helping to solve the nation's energy problems. The program included presentations of technical papers centered around exploration and disposal of nuclear fuel, general energy-related topics, and health-related issues, and workshops on model evaluation, risk analysis, analysis of large data sets, and resource estimation.

  1. Coal dust symposium

    Energy Technology Data Exchange (ETDEWEB)

    1981-03-01

    This paper gives a report of the paper presented at the symposium held in Hanover on 9 and 10 February 1981. The topics include: the behaviour of dust and coal dust on combustion and explosion; a report on the accidents which occurred at the Laegerdorf cement works' coal crushing and drying plant; current safety requirements at coal crushing and drying plant; and coal crushing and drying. Four papers are individually abstracted. (In German)

  2. 1979 DOE statistical symposium

    International Nuclear Information System (INIS)

    Gardiner, D.A.; Truett, T.

    1980-09-01

    The 1979 DOE Statistical Symposium was the fifth in the series of annual symposia designed to bring together statisticians and other interested parties who are actively engaged in helping to solve the nation's energy problems. The program included presentations of technical papers centered around exploration and disposal of nuclear fuel, general energy-related topics, and health-related issues, and workshops on model evaluation, risk analysis, analysis of large data sets, and resource estimation

  3. Impact of high-risk conjunctions on Active Debris Removal target selection

    OpenAIRE

    Lidtke, Aleksander A.; Lewis, Hugh G.; Armellin, Roberto

    2015-01-01

    All rights reserved.Space debris simulations show that if current space launches continue unchanged, spacecraft operations might become difficult in the congested space environment. It has been suggested that Active Debris Removal (ADR) might be necessary in order to prevent such a situation. Selection of objects to be targeted by ADR is considered important because removal of non-relevant objects will unnecessarily increase the cost of ADR. One of the factors to be used in this ADR target se...

  4. XV ESLAB Symposium

    CERN Document Server

    1981-01-01

    The 15th ESLAB symposium was held at the end of June 1981 in Amsterdam with the topic being X-ray astronomy. The aim of this symposium was to bring together the international astrophysical community in order to 1. review the present state of X-ray astronomy in the light of new observations gathered in recent missions and to review data on interesting objects in correlated wavelen8th regions; 2. discuss theoretical models describing the phenomena observed; 3. present ESA's European X-ray Observatory Satellite (EXOSAT) and to discuss future X-ray missions and their associated instrumenta­ tion. These topics seemed to be so interesting for the scientific community that more than 120 contributions were submitted. Of these, 94 were finally accepted and approximately 200 participants attended the 5-day meeting. The symposium was organised in nine sessions covering the whole field. Every main topic was introduced by a review lecture covering the state­ of-the-art. The aim of the meeting was to assess the impact of...

  5. LHC Nobel Symposium Proceedings

    Science.gov (United States)

    Ekelöf, Tord

    2013-12-01

    In the summer of 2012, a great discovery emerged at the Large Hadron Collider (LHC) at CERN in Geneva. A plethora of new precision data had already by then been collected by the ATLAS and CMS experiments at LHC, providing further extensive support for the validity of the Standard Model of particle physics. But what now appeared was the first evidence for what was not only the last unverified prediction of the Standard Model, but also perhaps the most decisive one: the prediction made already in 1964 of a unique scalar boson required by the theory of François Englert and Peter Higgs on how fundamental particles acquire mass. At that moment in 2012, it seemed particularly appropriate to start planning a gathering of world experts in particle physics to take stock of the situation and try to answer the challenging question: what next? By May 2013, when the LHC Nobel Symposium was held at the Krusenberg Mansion outside Uppsala in Sweden, the first signs of a great discovery had already turned into fully convincing experimental evidence for the existence of a scalar boson of mass about 125 GeV, having properties compatible with the 50-year-old prediction. And in October 2013, the evidence was deemed so convincing that the Swedish Royal Academy of Sciences awarded the Nobel Prize in Physics to Englert and Higgs for their pioneering work. At the same time the search at the LHC for other particles, beyond those predicted by the Standard Model, with heavier masses up to—and in some cases beyond—1 TeV, had provided no positive result. The triumph of the Standard Model seems resounding, in particular because the mass of the discovered scalar boson is such that, when identified with the Higgs boson, the Standard Model is able to provide predictions at energies as high as the Planck mass, although at the price of accepting that the vacuum would be metastable. However, even if there were some feelings of triumph, the ambience at the LHC Nobel Symposium was more one of

  6. DESIGN OF SLIT DAMS FOR CONTROLLING STONY DEBRIS FLOWS

    Institute of Scientific and Technical Information of China (English)

    Hui-Pang LIEN

    2003-01-01

    A new method to a slit dam for controlling the stony debris flow has been derived based on the mass conservation law of the stony debris flow passing through a slit dam and the laboratory experiment results.This new method is then combined with three primary efficiency expressions: the dimensionless sediment outflow ratio,the sediment concentration ratio,and the sediment storage rate to develop a simple module,with which the height and the spacing of the posts,as well as the total spacing of slit dam are determined.Furthermore,these expressions can also be applied to check those slit dams that have already been constructed with their effectiveness against various magnitudes of the debris flow. The comparison between these expressions and laboratory data is in reasonable agreement.

  7. TMI-2 core debris analysis

    International Nuclear Information System (INIS)

    Cook, B.A.; Carlson, E.R.

    1985-01-01

    One of the ongoing examination tasks for the damaged TMI-2 reactor is analysis of samples of debris obtained from the debris bed presently at the top of the core. This paper summarizes the results reported in the TMI-2 Core Debris Grab Sample Examination and Analysis Report, which will be available early in 1986. The sampling and analysis procedures are presented, and information is provided on the key results as they relate to the present core condition, peak temperatures during the transient, temperature history, chemical interactions, and core relocation. The results are then summarized

  8. Proceedings of the Symposium on the Effect of the Ionosphere on Space and Terrestrial Systems (1978) Held on January 24 - 26 1978

    Science.gov (United States)

    1978-01-01

    cathode and the space Is the anode. the perveance of such di- A W vde (2) odes is typically of ’unit’ porveance levels (I.e.. at 10-6 a .peres per volt to...plasma electron cur- Je(areres)(crn) vde (cm/sec)(3xO " ) (3’) rents to the underlying retallic surface are Insufficient to mintain its poto ’be and ,r a...8217., Vol. 39, U.S.A., pp SSS. Willisvts, D, j., (1976), "SCLOADS; An opera- tional Real-Ti Sol7r- Terrestral Envi- 3angt&, S. J., (197S). "Introduction

  9. Proceedings of the LLNL Technical Women`s Symposium

    Energy Technology Data Exchange (ETDEWEB)

    von Holtz, E. [ed.

    1993-12-31

    This report documents events of the LLNL Technical Women`s Symposium. Topics include; future of computer systems, environmental technology, defense and space, Nova Inertial Confinement Fusion Target Physics, technical communication, tools and techniques for biology in the 1990s, automation and robotics, software applications, materials science, atomic vapor laser isotope separation, technical communication, technology transfer, and professional development workshops.

  10. Welcome and introduction to symposium

    OpenAIRE

    humanities, Symposium on Information and technology in the arts and; McLaughlin, Jeremy Lee; Matusiak, Krystyna; Hirsh, Sandra

    2015-01-01

    Welcome and introduction slides used for presentation at the Virtual Symposium on Information and Technology in the Arts and Humanities, held April 22 and 23, 2015. The Symposium was co-sponsored by the ASIS&T (Association for Information Science and Technology) Special Interest Group for Arts and Humanities (SIG AH) and the Special Interest Group for Visualization, Images, and Sound (SIG VIS).

  11. 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

  12. NASA Orbital Debris Baseline Populations

    Science.gov (United States)

    Krisko, Paula H.; Vavrin, A. B.

    2013-01-01

    The NASA Orbital Debris Program Office has created high fidelity populations of the debris environment. The populations include objects of 1 cm and larger in Low Earth Orbit through Geosynchronous Transfer Orbit. They were designed for the purpose of assisting debris researchers and sensor developers in planning and testing. This environment is derived directly from the newest ORDEM model populations which include a background derived from LEGEND, as well as specific events such as the Chinese ASAT test, the Iridium 33/Cosmos 2251 accidental collision, the RORSAT sodium-potassium droplet releases, and other miscellaneous events. It is the most realistic ODPO debris population to date. In this paper we present the populations in chart form. We describe derivations of the background population and the specific populations added on. We validate our 1 cm and larger Low Earth Orbit population against SSN, Haystack, and HAX radar measurements.

  13. DebriSat Laboratory Analyses

    Science.gov (United States)

    2015-01-05

    droplets. Fluorine from Teflon wire insulation was also common in the SEM stub and witness plates deposits. Nano droplets of metallic materials...and Debris-LV debris. Aluminum was from the Al honeycomb, nadir and zenith panels, structural core and COPV liner. Aluminum oxide particles were...three pieces: Outer Nylon shell (sabot) with 2 part hollow aluminum insert. • ~600 grams, 8.6 cm diameter X 10.3 cm long – size of a soup can

  14. Backwater development by woody debris

    Science.gov (United States)

    Geertsema, Tjitske; Torfs, Paul; Teuling, Ryan; Hoitink, Ton

    2017-04-01

    Placement of woody debris is a common method for increasing ecological values in river and stream restoration, and is thus widely used in natural environments. Water managers, however, are afraid to introduce wood in channels draining agricultural and urban areas. Upstream, it may create backwater, depending on hydrodynamic characteristics including the obstruction ratio, the Froude number and the surface level gradient. Patches of wood may trigger or counter morphological activity, both laterally, through bank erosion and protection, and vertically, with pool and riffle formation. Also, a permeable construction composed of wood will weather over time. Both morphodynamic activity and weathering cause backwater effects to change in time. The purpose of this study is to quantify the time development of backwater effects caused by woody debris. Hourly water levels gauged upstream and downstream of patches and discharge are collected for five streams in the Netherlands. The water level drop over the woody debris patch relates to discharge in the streams. This relation is characterized by an increasing water level difference for an increasing discharge, up to a maximum. If the discharge increases beyond this level, the water level difference reduces to the value that may represent the situation without woody debris. This reduction depends primarily on the obstruction ratio of the woody debris in the channel cross-section. Morphologic adjustments in the stream and reorientation of the woody material reduce the water level drop over the patches in time. Our results demonstrate that backwater effects can be reduced by optimizing the location where woody debris is placed and manipulating the obstruction ratio. Current efforts are focussed on representing woody debris in a one-dimensional numerical model, aiming to obtain a generic tool to achieve a stream design with woody debris that minimizes backwater.

  15. Debris Disks: Probing Planet Formation

    OpenAIRE

    Wyatt, Mark C.

    2018-01-01

    Debris disks are the dust disks found around ~20% of nearby main sequence stars in far-IR surveys. They can be considered as descendants of protoplanetary disks or components of planetary systems, providing valuable information on circumstellar disk evolution and the outcome of planet formation. The debris disk population can be explained by the steady collisional erosion of planetesimal belts; population models constrain where (10-100au) and in what quantity (>1Mearth) planetesimals (>10km i...

  16. Vision-based Ground Test for Active Debris Removal

    Directory of Open Access Journals (Sweden)

    Seong-Min Lim

    2013-12-01

    Full Text Available Due to the continuous space development by mankind, the number of space objects including space debris in orbits around the Earth has increased, and accordingly, difficulties of space development and activities are expected in the near future. In this study, among the stages for space debris removal, the implementation of a vision-based approach technique for approaching space debris from a far-range rendezvous state to a proximity state, and the ground test performance results were described. For the vision-based object tracking, the CAM-shift algorithm with high speed and strong performance, and the Kalman filter were combined and utilized. For measuring the distance to a tracking object, a stereo camera was used. For the construction of a low-cost space environment simulation test bed, a sun simulator was used, and in the case of the platform for approaching, a two-dimensional mobile robot was used. The tracking status was examined while changing the position of the sun simulator, and the results indicated that the CAM-shift showed a tracking rate of about 87% and the relative distance could be measured down to 0.9 m. In addition, considerations for future space environment simulation tests were proposed.

  17. Earth Satellite Population Instability: Underscoring the Need for Debris Mitigation

    Science.gov (United States)

    Liou, Jer-chyi; Johnson, N. L.

    2006-01-01

    A recent study by NASA indicates that the implementation of international orbital debris mitigation measures alone will not prevent a significant increase in the artificial Earth satellite population, beginning in the second half of this century. Whereas the focus of the aerospace community for the past 25 years has been on the curtailment of the generation of long-lived orbital debris, active remediation of the current orbital debris population should now be reconsidered to help preserve near-Earth space for future generations. In particular, we show in this paper that even if launch operations were to cease today, the population of space debris would continue to grow. Further, proposed remediation techniques do not appear to offer a viable solution. We therefore recommend that, while the aerospace community maintains the current debris-limiting mission regulations and postmission disposal procedures, future emphasis should be placed on finding new remediation technologies for solving this growing problem. Since the launch of Sputnik 1, space activities have created an orbital debris environment that poses increasing impact risks to existing space systems, including human space flight and robotic missions (1, 2). Currently, more than 9,000 Earth orbiting man-made objects (including many breakup fragments), with a combined mass exceeding 5 million kilograms, are tracked by the US Space Surveillance Network and maintained in the US satellite catalog (3-5). Three accidental collisions between cataloged satellites during the period from late 1991 to early 2005 have already been documented (6), although fortunately none resulted in the creation of large, trackable debris clouds. Several studies conducted during 1991-2001 demonstrated, with assumed future launch rates, the unintended growth potential of the Earth satellite population, resulting from random, accidental collisions among resident space objects (7-13). In some low Earth orbit (LEO) altitude regimes where

  18. Nuclear science symposium, 26th and symposium on nuclear power systems, 11th, 1979

    International Nuclear Information System (INIS)

    Kerns, C.R.

    1980-01-01

    Proceedings include 163 of the papers presented at the combined meetings, as well as two papers delivered at the plenary session on plant control beyond the 1980's and ionizing radiation dose hazards. One-hundred-and-sixty-two papers are indexed separately. Nuclear Science symposium included calorimeters and specific ionization (17 papers); PWC and Drift Chambers (7 papers); photo/optical detectors (10 papers); semiconductor detectors (11 papers); nuclear circuits and systems (11 papers); space instrumentation (9 papers); medical instrumentation (30 papers); data preprocessing (6 papers); data acquisition (11 papers); environmental instrumentation (15 papers); reactor instrumentation (16 papers). Fifteen Nuclear Systems Symposium papers covered: safety, RFI effects, detectors, monitoring systems, reactor protection, multiplexing of circuits, standard application, emergency planning and preparedness and operator/instrumentation interactions

  19. PREFACE: International Symposium on Geohazards and Geomechanics (ISGG2015)

    Science.gov (United States)

    Utili, S.

    2015-09-01

    These Conference Proceedings contain the full papers in electronic format of the International Symposium on 'Geohazards and Geomechanics', held at University of Warwick, UK, on September 10-11, 2015. The Symposium brings together the complementary expertise of world leading groups carrying out research on the engineering assessment, prevention and mitigation of geohazards. A total of 58 papers, including 8 keynote lectures cover phenomena such as landslide initiation and propagation, debris flow, rockfalls, soil liquefaction, ground improvement, hazard zonation, risk mapping, floods and gas and leachates. The techniques reported in the papers to investigate geohazards involve numerical modeling (finite element method, discrete element method, material point method, meshless methods and particle methods), experimentation (laboratory experiments, centrifuge tests and field monitoring) and analytical simplified techniques. All the contributions in this volume have been peered reviewed according to rigorous international standards. However the authors take full responsibility for the content of their papers. Agreements are in place for the edition of a special issue dedicated to the Symposium in three international journals: Engineering Geology, Computational Particle Mechanics and International Journal of Geohazards and Environment. Authors of selected papers will be invited to submit an extended version of their work to these Journals that will independently assess the papers. The Symposium is supported by the Technical Committee 'Geo-mechanics from Micro to Macro' (TC105) of the International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE), 'Slope Stability in Engineering Practice' (TC208), 'Forensic Geotechnical Engineering' (TC302), the British Geotechnical Association and the EU FP7 IRSES project 'Geohazards and Geomechanics'. Also the organizers would like to thank all authors and their supporting institutions for their contributions. For any

  20. SYMPOSIUM: Rare decays

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    Late last year, a symposium entitled 'Rare Decays' attracted 115 participants to a hotel in Vancouver, Canada. These participants were particle physicists interested in checking conventional selection rules to look for clues of possible new behaviour outside today's accepted 'Standard Model'. For physicists, 'rare decays' include processes that have so far not been seen, explicitly forbidden by the rules of the Standard Model, or processes highly suppressed because the decay is dominated by an easier route, or includes processes resulting from multiple transitions

  1. Engineering and Technology Challenges for Active Debris Removal

    Science.gov (United States)

    Liou, Jer-Chyi

    2011-01-01

    After more than fifty years of space activities, the near-Earth environment is polluted with man-made orbital debris. The collision between Cosmos 2251 and the operational Iridium 33 in 2009 signaled a potential collision cascade effect, also known as the "Kessler Syndrome", in the environment. Various modelling studies have suggested that the commonly-adopted mitigation measures will not be sufficient to stabilize the future debris population. Active debris removal must be considered to remediate the environment. This paper summarizes the key issues associated with debris removal and describes the technology and engineering challenges to move forward. Fifty-four years after the launch of Sputnik 1, satellites have become an integral part of human society. Unfortunately, the ongoing space activities have left behind an undesirable byproduct orbital debris. This environment problem is threatening the current and future space activities. On average, two Shuttle window panels are replaced after every mission due to damage by micrometeoroid or orbital debris impacts. More than 100 collision avoidance maneuvers were conducted by satellite operators in 2010 to reduce the impact risks of their satellites with respect to objects in the U.S. Space Surveillance Network (SSN) catalog. Of the four known accident collisions between objects in the SSN catalog, the last one, collision between Cosmos 2251 and the operational Iridium 33 in 2009, was the most significant. It was the first ever accidental catastrophic destruction of an operational satellite by another satellite. It also signaled the potential collision cascade effect in the environment, commonly known as the "Kessler Syndrome," predicted by Kessler and Cour-Palais in 1978 [1]. Figure 1 shows the historical increase of objects in the SSN catalog. The majority of the catalog objects are 10 cm and larger. As of April 2011, the total objects tracked by the SSN sensors were more than 22,000. However, approximately 6000 of

  2. The physics of debris flows

    Science.gov (United States)

    Iverson, Richard M.

    1997-08-01

    Recent advances in theory and experimentation motivate a thorough reassessment of the physics of debris flows. Analyses of flows of dry, granular solids and solid-fluid mixtures provide a foundation for a comprehensive debris flow theory, and experiments provide data that reveal the strengths and limitations of theoretical models. Both debris flow materials and dry granular materials can sustain shear stresses while remaining static; both can deform in a slow, tranquil mode characterized by enduring, frictional grain contacts; and both can flow in a more rapid, agitated mode characterized by brief, inelastic grain collisions. In debris flows, however, pore fluid that is highly viscous and nearly incompressible, composed of water with suspended silt and clay, can strongly mediate intergranular friction and collisions. Grain friction, grain collisions, and viscous fluid flow may transfer significant momentum simultaneously. Both the vibrational kinetic energy of solid grains (measured by a quantity termed the granular temperature) and the pressure of the intervening pore fluid facilitate motion of grains past one another, thereby enhancing debris flow mobility. Granular temperature arises from conversion of flow translational energy to grain vibrational energy, a process that depends on shear rates, grain properties, boundary conditions, and the ambient fluid viscosity and pressure. Pore fluid pressures that exceed static equilibrium pressures result from local or global debris contraction. Like larger, natural debris flows, experimental debris flows of ˜10 m³ of poorly sorted, water-saturated sediment invariably move as an unsteady surge or series of surges. Measurements at the base of experimental flows show that coarse-grained surge fronts have little or no pore fluid pressure. In contrast, finer-grained, thoroughly saturated debris behind surge fronts is nearly liquefied by high pore pressure, which persists owing to the great compressibility and moderate

  3. The physics of debris flows

    Science.gov (United States)

    Iverson, R.M.

    1997-01-01

    Recent advances in theory and experimentation motivate a thorough reassessment of the physics of debris flows. Analyses of flows of dry, granular solids and solid-fluid mixtures provide a foundation for a comprehensive debris flow theory, and experiments provide data that reveal the strengths and limitations of theoretical models. Both debris flow materials and dry granular materials can sustain shear stresses while remaining static; both can deform in a slow, tranquil mode characterized by enduring, frictional grain contacts; and both can flow in a more rapid, agitated mode characterized by brief, inelastic grain collisions. In debris flows, however, pore fluid that is highly viscous and nearly incompressible, composed of water with suspended silt and clay, can strongly mediate intergranular friction and collisions. Grain friction, grain collisions, and viscous fluid flow may transfer significant momentum simultaneously. Both the vibrational kinetic energy of solid grains (measured by a quantity termed the granular temperature) and the pressure of the intervening pore fluid facilitate motion of grains past one another, thereby enhancing debris flow mobility. Granular temperature arises from conversion of flow translational energy to grain vibrational energy, a process that depends on shear rates, grain properties, boundary conditions, and the ambient fluid viscosity and pressure. Pore fluid pressures that exceed static equilibrium pressures result from local or global debris contraction. Like larger, natural debris flows, experimental debris flows of ???10 m3 of poorly sorted, water-saturated sediment invariably move as an unsteady surge or series of surges. Measurements at the base of experimental flows show that coarse-grained surge fronts have little or no pore fluid pressure. In contrast, finer-grained, thoroughly saturated debris behind surge fronts is nearly liquefied by high pore pressure, which persists owing to the great compressibility and moderate

  4. Academy of Program/Project & Engineering Leadership Orbital Debris Management and Risk Mitigation

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA Academy of Program/Project & Engineering Leadership (APPEL) is excited to announce the public release of Orbital Debris Management and Risk Mitigation,...

  5. An enhanced temperature index model for debris-covered glaciers accounting for thickness effect

    Science.gov (United States)

    Carenzo, M.; Pellicciotti, F.; Mabillard, J.; Reid, T.; Brock, B. W.

    2016-08-01

    strem curve. Its large number of parameters might be a limitation, but we show that the model is transferable in time and space to a second glacier with little loss of performance. We thus suggest that the new DETI model can be included in continuous mass balance models of debris-covered glaciers, because of its limited data requirements. As such, we expect its application to lead to an improvement in simulations of the debris-covered glacier response to climate in comparison with models that simply recalibrate empirical parameters to prescribe a constant across glacier reduction in melt.

  6. A brief scenario about the ''space pollution'' around the Earth

    International Nuclear Information System (INIS)

    Brito, T P; Celestino, C C; Moraes, R V

    2013-01-01

    In this work is presented a brief review about the main events generating of space debris around the Earth, occurred up to the present day. How the clouds of debris ''polluted'' the neighborhood of orbits in which the bodies were initially allocated is here analyzed. The implications of the growth of space debris existing on space missions as well as safety rules to control sources of debris are discussed

  7. Spatial and temporal patterns of stranded intertidal marine debris: is there a picture of global change?

    Science.gov (United States)

    Browne, Mark Anthony; Chapman, M Gee; Thompson, Richard C; Amaral Zettler, Linda A; Jambeck, Jenna; Mallos, Nicholas J

    2015-06-16

    Floating and stranded marine debris is widespread. Increasing sea levels and altered rainfall, solar radiation, wind speed, waves, and oceanic currents associated with climatic change are likely to transfer more debris from coastal cities into marine and coastal habitats. Marine debris causes economic and ecological impacts, but understanding the scope of these requires quantitative information on spatial patterns and trends in the amounts and types of debris at a global scale. There are very few large-scale programs to measure debris, but many peer-reviewed and published scientific studies of marine debris describe local patterns. Unfortunately, methods of defining debris, sampling, and interpreting patterns in space or time vary considerably among studies, yet if data could be synthesized across studies, a global picture of the problem may be avaliable. We analyzed 104 published scientific papers on marine debris in order to determine how to evaluate this. Although many studies were well designed to answer specific questions, definitions of what constitutes marine debris, the methods used to measure, and the scale of the scope of the studies means that no general picture can emerge from this wealth of data. These problems are detailed to guide future studies and guidelines provided to enable the collection of more comparable data to better manage this growing problem.

  8. Higher order sliding mode control of laser pointing for orbital debris mitigation

    Science.gov (United States)

    Palosz, Arthur

    This thesis explores the use of a space-based laser to clean up small orbital debris from near Earth space. This system's challenge is to quickly and precisely aim the laser beam at very small (laser beam onto the orbital debris. A Kalman Filter (KF) is designed to accurately track the orbital debris and generate a command signal for the controller. A second order Super Twisting Sliding Mode Controller (2-SMC) is designed to follow the command signal generated by the KF and to overcome the parametric uncertainties and external disturbances. The performance of the system is validated with a computer simulation created in MATLAB and Simulink.

  9. Symposium 3 of JENAM 2010

    CERN Document Server

    Recchi, Simone; Hensler, Gerhard; Dwarf Galaxies Keys to Galaxy Formation and Evolution

    2012-01-01

    Dwarf galaxy research constitutes an extremely vibrant field of astrophysical research, with many long-standing questions still unsettled and new ones constantly arising. The intriguing diversity of the dwarf galaxy population, observed with advanced ground-based and space-borne observatories over a wide spectral window providing an unprecedented level of detail, poses new challenges for both observers and theoreticians. The aim of this symposium was to bring together these two groups to exchange ideas and new results on the many evolutionary aspects of and open issues concerning dwarf galaxies. The main topics addressed include: • the birth of dwarf galaxies: theoretical concepts and observable relics across wavelength and time • the morphological, structural and chemical evolution of dwarf galaxies • possible evolutionary connections between early-type and late-type dwarfs • the star formation history of dwarf galaxies and its dependence on intrinsic and environmental properties • the origin ...

  10. Symposium 5 of JENAM 2010 /

    CERN Document Server

    Alves, João; Star clusters in the era of large surveys

    2012-01-01

    The symposium “Star Clusters in the Era of Large Surveys” was held in Lisbon on Sep 9-10 during the JENAM 2010. It served as a platform for discussing what and how recent, on-going and planned large-area ground-based and space-based surveys can contribute to producing a major leap in this research field, which has a strong European history. Scientific topics addressed included: • Cluster searches • Clustered vs. isolated star formation, large-scale star formation, enrichment of the field population • Structure, populations and evolution of the Milky Way • Cluster dynamics (internal and within the Milky Way) • Variability of stars in clusters (from time-resolved surveys) • Analysis techniques for large samples • Archiving This proceedings book provides a snapshot of the ongoing discussion on the role of large surveys in star cluster research, and serves as a reference volume for the state-of-the art in the field.

  11. NIC symposium 2010. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Muenster, Gernot [Muenster Univ. (Germany). Inst. fuer Theoretische Physik 1; Wolf, Dietrich [Duisburg-Essen Univ., Duisburg (Germany). Fakultaet fuer Physik; Kremer, Manfred (eds.) [Forschungszentrum Juelich GmbH (DE). Juelich Supercomputing Centre (JSC)

    2012-06-21

    The fifth NIC-Symposium gave an overview of the activities of the John von Neumann Institute for Computing (NIC) and of the results obtained in the last two years by research groups supported by the NIC. The large recent progress in supercomputing is highlighted by the fact that the newly installed Blue Gene/P system in Juelich - with a peak performance of 1 Petaflop/s - currently ranks number four in the TOP500 list. This development opens new dimensions in simulation science for researchers in Germany and Europe. NIC - a joint foundation of Forschungszentrum Juelich, Deutsches Elektronen-Synchrotron (DESY) and Gesellschaft fuer Schwerionenforschung (GSI) - supports with its members' supercomputer facilities about 130 research groups at universities and national labs working on computer simulations in various fields of science. Fifteen invited lectures covered selected topics in the following fields: Astrophysics Biophysics Chemistry Elementary Particle Physics Condensed Matter Materials Science Soft Matter Science Environmental Research Hydrodynamics and turbulence Plasma Physics Computer Science The talks are intended to inform a broad audience of scientists and the interested public about the research activities at NIC. The proceedings of the symposium cover projects that have been supported by the IBM supercomputers JUMP and IBM Blue Gene/P in Juelich and the APE topical computer at DESY-Zeuthen in an even wider range than the lectures.

  12. NIC symposium 2010. Proceedings

    International Nuclear Information System (INIS)

    Muenster, Gernot

    2012-01-01

    The fifth NIC-Symposium gave an overview of the activities of the John von Neumann Institute for Computing (NIC) and of the results obtained in the last two years by research groups supported by the NIC. The large recent progress in supercomputing is highlighted by the fact that the newly installed Blue Gene/P system in Juelich - with a peak performance of 1 Petaflop/s - currently ranks number four in the TOP500 list. This development opens new dimensions in simulation science for researchers in Germany and Europe. NIC - a joint foundation of Forschungszentrum Juelich, Deutsches Elektronen-Synchrotron (DESY) and Gesellschaft fuer Schwerionenforschung (GSI) - supports with its members' supercomputer facilities about 130 research groups at universities and national labs working on computer simulations in various fields of science. Fifteen invited lectures covered selected topics in the following fields: Astrophysics Biophysics Chemistry Elementary Particle Physics Condensed Matter Materials Science Soft Matter Science Environmental Research Hydrodynamics and turbulence Plasma Physics Computer Science The talks are intended to inform a broad audience of scientists and the interested public about the research activities at NIC. The proceedings of the symposium cover projects that have been supported by the IBM supercomputers JUMP and IBM Blue Gene/P in Juelich and the APE topical computer at DESY-Zeuthen in an even wider range than the lectures.

  13. NIC symposium 2010. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Muenster, Gernot [Muenster Univ. (Germany). Inst. fuer Theoretische Physik 1; Wolf, Dietrich [Duisburg-Essen Univ., Duisburg (Germany). Fakultaet fuer Physik; Kremer, Manfred [Forschungszentrum Juelich GmbH (DE). Juelich Supercomputing Centre (JSC)

    2012-06-21

    The fifth NIC-Symposium gave an overview of the activities of the John von Neumann Institute for Computing (NIC) and of the results obtained in the last two years by research groups supported by the NIC. The large recent progress in supercomputing is highlighted by the fact that the newly installed Blue Gene/P system in Juelich - with a peak performance of 1 Petaflop/s - currently ranks number four in the TOP500 list. This development opens new dimensions in simulation science for researchers in Germany and Europe. NIC - a joint foundation of Forschungszentrum Juelich, Deutsches Elektronen-Synchrotron (DESY) and Gesellschaft fuer Schwerionenforschung (GSI) - supports with its members' supercomputer facilities about 130 research groups at universities and national labs working on computer simulations in various fields of science. Fifteen invited lectures covered selected topics in the following fields: Astrophysics Biophysics Chemistry Elementary Particle Physics Condensed Matter Materials Science Soft Matter Science Environmental Research Hydrodynamics and turbulence Plasma Physics Computer Science The talks are intended to inform a broad audience of scientists and the interested public about the research activities at NIC. The proceedings of the symposium cover projects that have been supported by the IBM supercomputers JUMP and IBM Blue Gene/P in Juelich and the APE topical computer at DESY-Zeuthen in an even wider range than the lectures.

  14. International Evoked Potentials Symposium

    CERN Document Server

    1980-01-01

    The past decade has seen great progress in the measurement of evoked potentials in man; a steady increase in our understanding of their charac­ teristics, their origins and their usefulness; and a growing application in the field of clinical diagnosis. The topic is a truly multidisciplinary one. Important research contributions have been made by workers of many different backgrounds and clinical applications span the specialities. This book represents a revised and updated version of the work originally presented at the international evoked potential symposium held in Nottingham 4-6 1978. The Nottingham Symposium provided a forum for a state-of-the-art discussion amongst workers from many different disciplines and from many different countries. For each major topic in the field an expert review set the scene for discussion of current research presentations. This format is retained in the book: the chapters in Part A provide the context in which the research presented in Part B is set. The task of selecting m...

  15. Symposium Gyro Technology 1997

    Energy Technology Data Exchange (ETDEWEB)

    Sorg, H [ed.; Stuttgart Univ. (Germany). Inst. A fuer Mechanik

    1997-10-01

    This volume includes the twenty papers which were presented at the Symposium Gyro Technology 1997. The subjects that have been treated during the symposium were as follows: Performance and design of silicon micromachined gyro; improved rate gyroscope designs designated for fabrication by modern deep silicon etching; micromechanical vibratory rate gyroscopes fabricated in conventional CMOS; error modelling of silicon angular rate sensor; a capacitive accelerometer as an example for surface micromachined inertial sensors; initial production results of a new family of fiber optic gyroscopes; dual-axis multiplexed open loop fiber optic gyroscope; flattely supported vibratory gyro-sensor using a Trident-type tuning fork resonator; innovative mechanizations to optimize inertial sensors for high or low rate operations; design of a planar vibratory gyroscope using electrostatic actuation and electromanetic detection; fiber optic gyro based land navigation system; FOG AHRS and AHRS/GPS navigation system: the low cost solution; GPS/GLONASS/INS-navigation (GLOGINAV); small-sized integrated system of the sea mobile objects attitude and navigation; concepts for hybrid positioning; preliminary results from a large ring laser gyroscope for fundamental physics and geophysics; a `sense of balance` - AHRS with low-cost vibrating-gyroscopes for medical diagnostics; application of strapdown inertial systems of orientation and navigation in intrapipe moving diagnostic apparatus; investigation of a digital readout system for laser gyro; the use of angular rate multiple integrals as input signals for strapdown attitude algorithms. (AKF)

  16. MIPS Observations of the Fabulous Four Debris Disks

    Science.gov (United States)

    Su, K. Y. L.; Stansberry, J. A.; Rieke, G. H.; Trilling, D. E.; Stapelfeldt, K. R.; Werner, M. W.; Beichman, C.; Chen, C.; Marengo, M.; Megeath, T.; Backman, D.; van Cleve, J.

    2004-12-01

    The Multiband Imaging Photometer for Spitzer (MIPS) provides long-wavelength capability with imaging bands at 24, 70, and 160 um. We will present the MIPS images of the Fabulous Four Debris Disks: Beta Pictoris (A5 V), Epsilon Eridani (K2 V), Fomalhaut (A3 V) and Vega (A0 V). These systems discovered by IRAS possess large far-infrared excess emission above photosphere, indicating the existence of a circumstellar dusty disk. Given the main-sequence ages of these stars ( ˜12 Myr for Beta Pictoris, ˜730 Myr for Epsilon Eridani, ˜200 Myr for Fomalhaut, and ˜350 Myr for Vega), the dust in the systems could not be primordial as it would have been removed by radiation pressure and Poynting-Robertson drag on relatively short time scales ( ˜1E4 yr). The second-generation dust in such debris disks is thought to arise primarily from collisions between planetesimals (asteroids) and from cometary activity; however, details about the debris formation and evolution are not well understood. With the sensitivity and angular resolution of the Spitizer Space Telescope, the structures of these nearby debris disks were mapped in great detail to study the disks' spatial structures at mid- to far-infrared wavelengths. These high spatial resolution images provide unprecedented new constraints on the the dust properties in the systems and limits on the origin of dusty debris. Support for this work was provided by NASA through Contract Number 960785 issued by JPL/Caltech.

  17. Debris flows susceptibility mapping under tropical rain conditions in Rwanda.

    Science.gov (United States)

    Nduwayezu, Emmanuel; Nsengiyumva, Jean-Baptiste; BUgnon, Pierre-Charles; Jaboyedoff, Michel; Derron, Marc-Henri

    2017-04-01

    Rwanda is a densely populated country. It means that all the space is exploited, including sometimes areas with very steep slopes. This has as for consequences that during the rainy season slopes with human activities are affected by gravitational processes, mostly debris and mud flows and shallow landslides. The events of early May 2016 (May 8 and 9), with more than 50 deaths, are an illustration of these frequents landslides and inundations. The goal of this work is to produce a susceptibility map for debris/mud flows at regional/national scale. Main available pieces of data are a national digital terrain model at 10m resolution, bedrock and soil maps, and information collected during field visits on some specific localities. The first step is the characterization of the slope angle distribution for the different types of bedrock or soils (decomposition in Gaussian populations). Then, the combination of this information with other geomorphic and hydrologic parameters is used to define potential source areas of debris flows. Finally, propagation maps of debris flows are produced using FLOW-R (Horton et al. 2013). Horton, P., Jaboyedoff, M., Rudaz, B., and Zimmermann, M.: Flow-R, a model for susceptibility mapping of debris flows and other gravitational hazards at a regional scale, Nat. Hazards Earth Syst. Sci., 13, 869-885, doi:10.5194/nhess-13-869-2013, 2013. The paper is in open access.

  18. Disaster Debris Recovery Database - Landfills

    Science.gov (United States)

    The US EPA Region 5 Disaster Debris Recovery Database includes public datasets of over 6,000 composting facilities, demolition contractors, transfer stations, landfills and recycling facilities for construction and demolition materials, electronics, household hazardous waste, metals, tires, and vehicles in the states of Illinois, Indiana, Iowa, Kentucky, Michigan, Minnesota, Missouri, North Dakota, Ohio, Pennsylvania, South Dakota, West Virginia and Wisconsin.In this update, facilities in the 7 states that border the EPA Region 5 states were added to assist interstate disaster debris management. Also, the datasets for composters, construction and demolition recyclers, demolition contractors, and metals recyclers were verified and source information added for each record using these sources: AGC, Biocycle, BMRA, CDRA, ISRI, NDA, USCC, FEMA Debris Removal Contractor Registry, EPA Facility Registry System, and State and local listings.

  19. Disaster Debris Recovery Database - Recovery

    Science.gov (United States)

    The US EPA Region 5 Disaster Debris Recovery Database includes public datasets of over 6,000 composting facilities, demolition contractors, transfer stations, landfills and recycling facilities for construction and demolition materials, electronics, household hazardous waste, metals, tires, and vehicles in the states of Illinois, Indiana, Iowa, Kentucky, Michigan, Minnesota, Missouri, North Dakota, Ohio, Pennsylvania, South Dakota, West Virginia and Wisconsin.In this update, facilities in the 7 states that border the EPA Region 5 states were added to assist interstate disaster debris management. Also, the datasets for composters, construction and demolition recyclers, demolition contractors, and metals recyclers were verified and source information added for each record using these sources: AGC, Biocycle, BMRA, CDRA, ISRI, NDA, USCC, FEMA Debris Removal Contractor Registry, EPA Facility Registry System, and State and local listings.

  20. Research symposium proceedings. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1991-12-31

    THE research symposium was organized to present the cutting edge research for PET by individuals from leading institutions throughout the world. The Institute for Clinical PET (ICP) has focused its annual meeting on the clinical applications of PET.

  1. International symposium on NMR spectroscopy

    International Nuclear Information System (INIS)

    The publication consists of 32 papers and presentations from the field of NMR spectroscopy applications submitted to the International Symposium on NMR Spectroscopy held at Smolenice between 29 Sep and 3 Oct, 1980. (B.S.)

  2. Proceedings Forest & Field Fuels Symposium

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-07-01

    The purpose of the symposium is to examine two specific renewable resources, forest and field fuels, to pinpoint areas where funding of RD&D would be effective in expanding their marketability and use as substitutes for imported oil.

  3. Third Symposium on Macrocyclic Compounds

    International Nuclear Information System (INIS)

    1979-01-01

    At the Third Symposium on Macrocyclic Compounds there were sessions on facilitated transport, analytical applications, organic synthesis and reactions, phase transfer catalysis, and metal complexation. Abstracts of the individual presentations are included

  4. VIII international electric vehicle symposium

    Energy Technology Data Exchange (ETDEWEB)

    1986-01-01

    The proceedings from the symposium are presented. Major topics discussed include: battery technology, powertrains; hybrid vehicles, marketing and economics, propulsion, and electric vehicle design and performance. Each paper has been separately indexed for inclusion in the Energy Data Base.

  5. Fourth symposium on macrocyclic compounds

    International Nuclear Information System (INIS)

    Christensen, J.J.; Izatt, R.M.

    1980-01-01

    Both theoretical and experimental aspects of the properties and behavior of synthetic and naturally occurring macrocyclic compounds are covered in this symposium. This document contains abstracts of the papers

  6. ACS Symposium on Molecular Tribology

    National Research Council Canada - National Science Library

    Gellman, Andrew

    2002-01-01

    .... The aspects of tribology covered by the symposium were quite broad but included a number of areas of importance to Air Force technologies including vapor phase lubrication, lubrication of MEMS...

  7. Debris Flows and Related Phenomena

    Science.gov (United States)

    Ancey, C.

    Torrential floods are a major natural hazard, claiming thousands of lives and millions of dollars in lost property each year in almost all mountain areas on the Earth. After a catastrophic eruption of Mount St. Helen in the USA in May 1980, water from melting snow, torrential rains from the eruption cloud, and water displaced from Spirit Lake mixed with deposited ash and debris to produce very large debris flows and cause extensive damage and loss of life [1]. During the 1985 eruption of Nevado del Ruiz in Colombia, more than 20,000 people perished when a large debris flow triggered by the rapid melting of snow and ice at the volcano summit, swept through the town of Armero [2]. In 1991, the eruption of Pinatubo volcano in the Philippines disperses more than 5 cubic kilometres of volcanic ash into surrounding valleys. Much of that sediment has subsequently been mobilised as debris flows by typhoon rains and has devastated more than 300 square kilometres of agricultural land. Even, in Eur opean countries, recent events that torrential floods may have very destructive effects (Sarno and Quindici in southern Italy in May 1998, where approximately 200 people were killed). The catastrophic character of these floods in mountainous watersheds is a consequence of significant transport of materials associated with water flows. Two limiting flow regimes can be distinguished. Bed load and suspension refer to dilute transport of sediments within water. This means that water is the main agent in the flow dynamics and that the particle concentration does not exceed a few percent. Such flows are typically two-phase flows. In contrast, debris flows are mas s movements of concentrated slurries of water, fine solids, rocks and boulders. As a first approximation, debris flows can be treated as one-phase flows and their flow properties can be studied using classical rheological methods. The study of debris flows is a very exciting albeit immature science, made up of disparate elements

  8. Marine Debris Research, Prevention, and Reduction Act

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Marine Debris Research, Prevention, and Reduction Act legally establishes the National Oceanic and Atmospheric Administration's (NOAA) Marine Debris Program. The...

  9. The ecological impacts of marine debris

    NARCIS (Netherlands)

    Rochman, Chelsea M.; Browne, Mark Anthony; Underwood, A.J.; Franeker, Van Jan A.; Thompson, Richard C.; Amaral-Zettler, Linda A.

    2016-01-01

    Anthropogenic debris contaminates marine habitats globally, leading to several perceived ecological impacts. Here, we critically and systematically review the literature regarding impacts of debris from several scientific fields to understand the weight of evidence regarding the ecological

  10. DebriSat Project Update and Planning

    Science.gov (United States)

    Sorge, M.; Krisko, P. H.

    2016-01-01

    DebriSat Reporting Topics: DebriSat Fragment Analysis Calendar; Near-term Fragment Extraction Strategy; Fragment Characterization and Database; HVI (High-Velocity Impact) Considerations; Requirements Document.

  11. Spacecraft-plasma-debris interaction in an ion beam shepherd mission

    Science.gov (United States)

    Cichocki, Filippo; Merino, Mario; Ahedo, Eduardo

    2018-05-01

    This paper presents a study of the interaction between a spacecraft, a plasma thruster plume and a free floating object, in the context of an active space debris removal mission based on the ion beam shepherd concept. The analysis is performed with the EP2PLUS hybrid code and includes the evaluation of the transferred force and torque to the target debris, its surface sputtering due to the impinging hypersonic ions, and the equivalent electric circuit of the spacecraft-plasma-debris interaction. The electric potential difference that builds up between the spacecraft and the debris, the ion backscattering and the backsputtering contamination of the shepherd satellite are evaluated for a nominal scenario. A sensitivity analysis is carried out to evaluate quantitatively the effects of electron thermodynamics, ambient plasma, heavy species collisions, and debris position.

  12. Automated Vehicles Symposium 2015

    CERN Document Server

    Beiker, Sven

    2016-01-01

    This edited book comprises papers about the impacts, benefits and challenges of connected and automated cars. It is the third volume of the LNMOB series dealing with Road Vehicle Automation. The book comprises contributions from researchers, industry practitioners and policy makers, covering perspectives from the U.S., Europe and Japan. It is based on the Automated Vehicles Symposium 2015 which was jointly organized by the Association of Unmanned Vehicle Systems International (AUVSI) and the Transportation Research Board (TRB) in Ann Arbor, Michigan, in July 2015. The topical spectrum includes, but is not limited to, public sector activities, human factors, ethical and business aspects, energy and technological perspectives, vehicle systems and transportation infrastructure. This book is an indispensable source of information for academic researchers, industrial engineers and policy makers interested in the topic of road vehicle automation.

  13. 10th Schaeffler Symposium

    CERN Document Server

    2014-01-01

    Every four years, Schaeffler provides an insight into its latest developments and technologies from the engine, transmission and chassis as well as hybridization and electric mobility sectors. In 2014 the Schaeffler Symposium with the motto “Solving the Powertrain Puzzle” took place from 3th to 4th of April in Baden-Baden. Mobility for tomorrow is the central theme of this proceeding. The authors are discussing the different requirements, which are placed on mobility in different regions of the world. In addition to the company's work in research and development, a comprehensive in-house mobility study also provides a reliable basis for the discussion. The authors are convinced that there will be a paradigm shift in the automotive industry. Issues such as increasing efficiency and advancing electrification of the powertrain, automatic and semi-automatic driving, as well as integration in information networks will define the automotive future. In addition, the variety of solutions available worldwide will ...

  14. NATO Telecommunications Symposium

    CERN Document Server

    Lucas, William; Conrath, David

    1978-01-01

    This book contains the proceedings of the first international symposium devoted to research on the evaluation and planning of new person-to-person telecommunication systems. It was sponsored by NATO's Special Programme Panel on Systems Science and took place, in September 1977, at the University of Bergamo in the north of Italy. Telecommunication systems which provide for communication be­ tween people, rather than computers or other instruments, are of two kinds. There are mass communication systems (broadcast radio and television) and interpersonal systems (for example, the telephone and Telex) which join together individuals or small groups. Here we have included in the interpersonal category certain systems for re­ trieving information from computers, essentially those systems in which the role of the computer 1s primarily to act as a store and to identify that information which best fits a user's request. (This excludes management information systems in which the computer performs important transformat...

  15. Objectives of the symposium

    International Nuclear Information System (INIS)

    Genter, N.E.

    1996-01-01

    The objective of this symposium was to discuss the sorts of evidence of molecular alterations in DNA which can be used to study causation of the stochastic effects of importance in radiation protection. Specifically, the aim was to address the following: what sort of indications might show whether a cancer was caused by radiation; whether there is a radiogenic signature to distinguish damage caused by ionizing radiation; whether bio-markers might be available for susceptibility, for exposure, for biological consequences. Despite a number of epidemiological studies (referred to), there is no clear, credible, defensible answer as to whether low-level radiation increases the risk of cancer. A new ethical question is, what rules should be in place for identifying and protecting genetically sensitive individuals. 1 tab

  16. Objectives of the symposium

    International Nuclear Information System (INIS)

    Osborne, R.V.

    1992-01-01

    The author defined the objectives of the symposium as follows: to present and examine the recent evidence associating clusters of leukemia with sources of ionizing radiation; to examine the statistical basis for the analysis of clustering; to examine the underlying assumptions in epidemiological studies that clusters must have an environmental cause; to examine the extent to which we can take into account the biological causes of non-randomness in populations, particularly those of geographic and genetic origin; to evaluate the relative merits of different kinds of epidemiological studies for yielding significant information concerning clustering; to consider the potential utility of combining the results from existing studies, and whether new epidemiological studies might be helpful; to consider what other directions, including application of the technologies of molecular biology, are likely to help clarify the underlying mechanisms or causes

  17. SYMPOSIUM: Particle identification

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1989-07-15

    Typical elementary particle experiments consist of a source of interactions (an external beam and a fixed target or two colliding beams) and a detector system including most of the following components: a tracking system and analysis magnet, calorimetry (measurement of energy deposition), hadron and electron identification, muon detection, trigger counters and processors, and data acquisition electronics. Experiments aimed at future high luminosity hadron collider (proton-proton or proton-antiproton) projects such as an upgraded Tevatron at Fermilab, the Large Hadron Collider (LHC) idea at CERN, and the proposed US Superconducting Supercollider (SSC), must ideally cover the entire solid angle and be capable of not only surviving the collisions, but also providing high resolution event information at incredible interaction rates. The Symposium on Particle Identification at High Luminosity Hadron Colliders held at Fermilab from 5-7 April (sponsored by Fermilab, the US Department of Energy, and the SSC Central Design Group) focused on this single facet of detector technology.

  18. Design Modelling Symposium 2015

    CERN Document Server

    Tamke, Martin; Gengnagel, Christoph; Faircloth, Billie; Scheurer, Fabian

    2015-01-01

    This book reflects and expands on the current trend in the building industry to understand, simulate and ultimately design buildings by taking into consideration the interlinked elements and forces that act on them. This approach overcomes the traditional, exclusive focus on building tasks, while posing new challenges in all areas of the industry from material and structural to the urban scale. Contributions from invited experts, papers and case studies provide the reader with a comprehensive overview of the field, as well as perspectives from related disciplines, such as computer science. The chapter authors were invited speakers at the 5th Symposium "Modelling Behaviour", which took place at the CITA in Copenhagen in September 2015.

  19. Automated Vehicles Symposium 2014

    CERN Document Server

    Beiker, Sven; Road Vehicle Automation 2

    2015-01-01

    This paper collection is the second volume of the LNMOB series on Road Vehicle Automation. The book contains a comprehensive review of current technical, socio-economic, and legal perspectives written by experts coming from public authorities, companies and universities in the U.S., Europe and Japan. It originates from the Automated Vehicle Symposium 2014, which was jointly organized by the Association for Unmanned Vehicle Systems International (AUVSI) and the Transportation Research Board (TRB) in Burlingame, CA, in July 2014. The contributions discuss the challenges arising from the integration of highly automated and self-driving vehicles into the transportation system, with a focus on human factors and different deployment scenarios. This book is an indispensable source of information for academic researchers, industrial engineers, and policy makers interested in the topic of road vehicle automation.

  20. 2nd Abel Symposium

    CERN Document Server

    Nunno, Giulia; Lindstrøm, Tom; Øksendal, Bernt; Zhang, Tusheng

    2007-01-01

    Kiyosi Ito, the founder of stochastic calculus, is one of the few central figures of the twentieth century mathematics who reshaped the mathematical world. Today stochastic calculus is a central research field with applications in several other mathematical disciplines, for example physics, engineering, biology, economics and finance. The Abel Symposium 2005 was organized as a tribute to the work of Kiyosi Ito on the occasion of his 90th birthday. Distinguished researchers from all over the world were invited to present the newest developments within the exciting and fast growing field of stochastic analysis. The present volume combines both papers from the invited speakers and contributions by the presenting lecturers. A special feature is the Memoirs that Kiyoshi Ito wrote for this occasion. These are valuable pages for both young and established researchers in the field.

  1. SYMPOSIUM: Multiparticle 82

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    The thirteenth symposium in the successful series on multiparticle dynamics was held from 6-11 June in the picturesque North Holland village of Volendam. While originally confined to hadron-hadron interactions, multiparticle dynamics is now of interest in all types of particle collision. Results on proton-antiproton collisions at CERN, both in the SPS and the ISR, are a talking point wherever particle physicists meet, and Volendam was no exception. Also prominent at Volendam were ultrarelativistic effects in nucleus-nucleus collisions. However the main aim of this year's meeting was to review the common features of hadrons produced in different types of collision (lepton-lepton, lepton-hadron and hadron-hadron)

  2. Renewable Energy Symposium

    International Nuclear Information System (INIS)

    2016-01-01

    Representatives of state universities, public institutions and Costa Rican private sector, and American experts have exposed projects or experiences about the use and generation of renewable energy in different fields. The thematics presented have been about: development of smart grids and design of electrical energy production systems that allow money saving and reducing emissions to the environment; studies on the use of non-traditional plants and agricultural waste; sustainable energy model in the process of coffee production; experiments from biomass for the fabrication of biodiesel, biogas production and storage; and the use of non-conventional energy. Researches were presented at the Renewable Energy Symposium, organized by the Centro de Investigacion en Estructuras Microscopicas and support of the Vicerrectoria de Investigacion, both from the Universidad de Costa Rica [es

  3. 3rd Abel Symposium

    CERN Document Server

    Owren, Brynjulf

    2008-01-01

    The 2006 Abel symposium is focusing on contemporary research involving interaction between computer science, computational science and mathematics. In recent years, computation has been affecting pure mathematics in fundamental ways. Conversely, ideas and methods of pure mathematics are becoming increasingly important within computational and applied mathematics. At the core of computer science is the study of computability and complexity for discrete mathematical structures. Studying the foundations of computational mathematics raises similar questions concerning continuous mathematical structures. There are several reasons for these developments. The exponential growth of computing power is bringing computational methods into ever new application areas. Equally important is the advance of software and programming languages, which to an increasing degree allows the representation of abstract mathematical structures in program code. Symbolic computing is bringing algorithms from mathematical analysis into the...

  4. SYMPOSIUM: Multiparticle Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1984-09-15

    How is the seemingly simple world of quarks and leptons related to the complicated phenomena that particle physicists see in their detectors? This was the theme of the 15th Symposium on multiparticle dynamics held in Lund, Sweden, from 11-16 June. Apart from the many results from the CERN proton-antiproton Collider, a recurrent theme during the conference was the growing awareness of the importance of quark 'hadronization'. Everyone knows that isolated quarks have never been found in Nature. Only those combinations of quarks and antiquarks that form hadrons have been detected. The dressing of the quarks to become hadrons goes under the name 'hadronization' and this process is very difficult to describe theoretically from first principles. Even the currently accepted theory for strong quark interactions — quantum chromodynamics, QCD — has difficulties. QCD has been shown to be a good theory describing 'small distance phenomena' — small compared to a hadron.

  5. DebriSat Hypervelocity Impact Test

    Science.gov (United States)

    2015-08-01

    public release; distribution unlimited.  Targets: Scaled Multishock Shield, DebrisLV, and DebriSat  500-600 g hollow aluminum and nylon projectile... insulation . DebriSat’s internal components were structurally similar to real flight hardware but were nonfunctional. AEDC-TR-15-S-2 6...structures with an AL 5052 honeycomb core and M55J carbon fiber face sheets. The basic system characteristics of the DebriSat are given in Table 1

  6. Proceedings of the thirty second national symposium on plasma science and technology: plasma for societal benefits: book of abstracts

    International Nuclear Information System (INIS)

    Dave, Sandhya; Shravan Kumar, S.; Vijayakumaran; Singh, Raj; Awasthi, L.M.

    2017-01-01

    This symposium covers topics on: basic plasma, computer modelling for plasma, exotic plasma, industrial plasma, laser plasma theory, nuclear fusion, plasma diagnostics, laser plasma, plasma processing, pulsed power, space and astrophysical plasma. Papers relevant to INIS are indexed separately

  7. Photometric Studies of GEO Debris

    Science.gov (United States)

    Seitzer, Patrick; Cowardin, Heather M.; Barker, Edwin; Abercromby, Kira J.; Foreman, Gary; Horstman, Matt

    2009-01-01

    The photometric signature of a debris object can be useful in determining what the physical characteristics of a piece of debris are. We report on optical observations in multiple filters of debris at geosynchronous Earth orbit (GEO). Our sample is taken from GEO objects discovered in a survey with the University of Michigan's 0.6-m aperture Schmidt telescope MODEST (for Michigan Orbital DEbris Survey Telescope), and then followed up in real-time with the SMARTS (Small and Medium Aperture Research Telescope System) 0.9-m at CTIO for orbits and photometry. Our goal is to determine 6 parameter orbits and measure colors for all objects fainter than R = 15 th magnitude that are discovered in the MODEST survey. At this magnitude the distribution of observed angular rates changes significantly from that of brighter objects. There are two objectives: 1. Estimate the orbital distribution of objects selected on the basis of two observational criteria: brightness (magnitude) and angular rates. 2. Obtain magnitudes and colors in standard astronomical filters (BVRI) for comparison with reflectance spectra of likely spacecraft materials. What is the faint debris likely to be? In this paper we report on the photometric results. For a sample of 50 objects, more than 90 calibrated sequences of R-B-V-I-R magnitudes have been obtained with the CTIO 0.9-m. For objects that do not show large brightness variations, the colors are largely redder than solar in both B-R and R-I. The width of the color distribution may be intrinsic to the nature of the surfaces, but also could be that we are seeing irregularly shaped objects and measuring the colors at different times with just one telescope. For a smaller sample of objects we have observed with synchronized CCD cameras on the two telescopes. The CTIO 0.9-m observes in B, and MODEST in R. The CCD cameras are electronically linked together so that the start time and duration of observations are the same to better than 50 milliseconds. Thus

  8. Analysis of Space Station Operations in the Space Debris Environment.

    Science.gov (United States)

    1984-12-01

    o, a Itmd, a Ithi , umco, s atpop, s tplo, a atpm d , aatphi , + expobj,dlo,dmd,dhi,nexplo,nexpuid,nexphi, colide , + objlo,objmd,objhi,cobjlo,cobjmd...tisoic, tiioc,flumco, + soivsl,soivsm, soivsh,numrun double precision c, colide ,rholo,rhomd, rhoh. equivalence(nset(l ),qset(l)) net-7 5000 ncrdr-5...del tlo,del tmd,del thi, + *1 tlo,altad,althi ,numco,satpop,satplo,aatpmd,satphi, + expobj,dlo,dad,dhi,nexplo,nexpudnexphi, colide , + objlo

  9. Symposium Promotes Technological Literacy through STEM

    Science.gov (United States)

    Havice, Bill; Marshall, Jerry

    2009-01-01

    This article describes a symposium which promotes technological literacy through science, technology, engineering, and mathematics (STEM). The three-day symposium titled, "The Anderson, Oconee, Pickens Symposium on Teaching and Learning STEM Standards for the 21st Century," was held August 4-6, 2008 at the Tri-County Technical College…

  10. Impact risk assessment for the ATV using ESABASE/DEBRIS

    Science.gov (United States)

    Beltrami Karlezi, P.; Drolshagen, G.; Lambert, M.

    2001-10-01

    The European Space Agency ESA participates in the International Space Station with various programs, one of them being the Automated Transfer Vehicle (ATV). The ATV is an unmanned servicing and logistics vehicle launched on Ariane 5 and designed to fulfil different roles like cargo transport, re-supply of fuel and consumables and orbit re-boost of the International Space Station (ISS). For this reason it is important that the risks imposed on these modules by meteoroids and orbital debris are calculated accurately. Following such calculations the Meteoroid and Orbital Debris Protection System (M/ODPS) can be optimised. This paper presents the results of the risk assessment of meteoroids and space debris for the ATV spacecraft attached to the ISS using different shield configurations. The results are presented as the probability of no penetration (PNP) for each component and each configuration. They are compared to a target PNP requirement of 0.999 for 135 days and the weight penalty produced by the extra shielding is given.

  11. Detecting debris flows using ground vibrations

    Science.gov (United States)

    LaHusen, Richard G.

    1998-01-01

    Debris flows are rapidly flowing mixtures of rock debris, mud, and water that originate on steep slopes. During and following volcanic eruptions, debris flows are among the most destructive and persistent hazards. Debris flows threaten lives and property not only on volcanoes but far downstream in valleys that drain volcanoes where they arrive suddenly and inundate entire valley bottoms. Debris flows can destroy vegetation and structures in their path, including bridges and buildings. Their deposits can cover roads and railways, smother crops, and fill stream channels, thereby reducing their flood-carrying capacity and navigability.

  12. NASA Orbital Debris Large-Object Baseline Population in ORDEM 3.0

    Science.gov (United States)

    Krisco, Paula H.; Vavrin, A. B.; Anz-Meador, P. D.

    2013-01-01

    The NASA Orbital Debris Program Office (ODPO) has created and validated high fidelity populations of the debris environment for the latest Orbital Debris Engineering Model (ORDEM 3.0). Though the model includes fluxes of objects 10 um and larger, this paper considers particle fluxes for 1 cm and larger debris objects from low Earth orbit (LEO) through Geosynchronous Transfer Orbit (GTO). These are validated by several reliable radar observations through the Space Surveillance Network (SSN), Haystack, and HAX radars. ORDEM 3.0 populations were designed for the purpose of assisting, debris researchers and sensor developers in planning and testing. This environment includes a background derived from the LEO-to-GEO ENvironment Debris evolutionary model (LEGEND) with a Bayesian rescaling as well as specific events such as the FY-1C anti-satellite test, the Iridium 33/Cosmos 2251 accidental collision, and the Soviet/Russian Radar Ocean Reconnaissance Satellite (RORSAT) sodium-potassium droplet releases. The environment described in this paper is the most realistic orbital debris population larger than 1 cm, to date. We describe derivations of the background population and added specific populations. We present sample validation charts of our 1 cm and larger LEO population against Space Surveillance Network (SSN), Haystack, and HAX radar measurements.

  13. International Symposium on Nuclear Safety

    International Nuclear Information System (INIS)

    2013-03-01

    Nuclear Regulatory Authority of the Slovak Republic and the Embassy of Japan in the Slovak Republic, under the auspices of the Deputy Prime Minister and Minister of Foreign and European Affairs Mr Lajcak organized International Symposium on Nuclear Safety on 14 and 15 March 2013. The symposium took place almost exactly two years after the occurrence of accidents at the Japanese nuclear power plant Fukushima Daichi. The main mission of the symposium was an attempt to contribute to the improvement of nuclear safety by sharing information and lessons presented by Japanese experts with experts from the region, the International Atomic Energy Agency (IAEA) and the European Commission. The aim of the symposium, unlike many other events organized in connection with the events in Fukushima Daichi NPP, was a summary of the results of stress tests and measures update adopted by the international community, especially within Europe. Panel discussion was included to the program of the symposium for this aim was, mainly focused on the current state of implementation of the National Action Plan of the Slovak Republic, the Czech Republic, Poland, Ukraine and Switzerland and the IAEA Action Plan.

  14. Detailed debris flow hazard assessment in Andorra: A multidisciplinary approach

    Science.gov (United States)

    Hürlimann, Marcel; Copons, Ramon; Altimir, Joan

    2006-08-01

    In many mountainous areas, the rapid development of urbanisation and the limited space in the valley floors have created a need to construct buildings in zones potentially exposed to debris flow hazard. In these zones, a detailed and coherent hazard assessment is necessary to provide an adequate urban planning. This article presents a multidisciplinary procedure to evaluate the debris flow hazard at a local scale. Our four-step approach was successfully applied to five torrent catchments in the Principality of Andorra, located in the Pyrenees. The first step consisted of a comprehensive geomorphologic and geologic analysis providing an inventory map of the past debris flows, a magnitude-frequency relationship, and a geomorphologic-geologic map. These data were necessary to determine the potential initiation zones and volumes of future debris flows for each catchment. A susceptibility map and different scenarios were the principal outcome of the first step, as well as essential input data for the second step, the runout analysis. A one-dimensional numerical code was applied to analyse the scenarios previously defined. First, the critical channel sections in the fan area were evaluated, then the maximum runout of the debris flows on the fan was studied, and finally simplified intensity maps for each defined scenario were established. The third step of our hazard assessment was the hazard zonation and the compilation of all the results from the two previous steps in a final hazard map. The base of this hazard map was the hazard matrix, which combined the intensity of the debris flow with its probability of occurrence and determined a certain hazard degree. The fourth step referred to the hazard mitigation and included some recommendations for hazard reduction. In Andorra, this four-step approach is actually being applied to assess the debris flow hazard. The final hazard maps, at 1 : 2000 scale, provide an obligatory tool for local land use planning. Experience

  15. Is the Sky Really Falling? An Overview of Orbital Debris

    Science.gov (United States)

    Hull, Scott M.

    2015-01-01

    Orbital debris has been a prominent topic for a while, even before the movie Gravity came out. An anti-satellite test and a collision with an operational satellite both produced large highly-publicized debris clouds within recent years. While large objects like abandoned satellites and rocket bodies may be the most recognizable and identifiable concerns, a majority of the daily threat comes from the much more numerous smaller particles. In fact, small particle penetration continues to rank among the leading risks for manned space missions to the International Space Station and beyond. How much 'stuff' is up there, where did it come from, what harm can it do, and what is being done about it? These questions and more will be discussed.

  16. Warm Debris Disks from WISE

    Science.gov (United States)

    Padgett, Deborah L.

    2011-01-01

    "The Wide Field Infrared Survey Explorer (WISE) has just completed a sensitive all-sky survey in photometric bands at 3.4, 4.6, 12, and 22 microns. We report on a preliminary investigation of main sequence Hipparcos and Tycho catalog stars with 22 micron emission in excess of photospheric levels. This warm excess emission traces material in the circumstellar region likely to host terrestrial planets and is preferentially found in young systems with ages warm debris disk candidates are detected among FGK stars and a similar number of A stars within 120 pc. We are in the process of obtaining spectra to determine spectral types and activity level of these stars and are using HST, Herschel and Keck to characterize the dust, multiplicity, and substellar companions of these systems. In this contribution, we will discuss source selection methods and individual examples from among the WISE debris disk candidates. "

  17. Memorial Symposium for Willibald Jentschke

    CERN Multimedia

    2002-01-01

    Willibald 'Willi' Jentschke, Director General of CERN from 1971 to 1975 and founder of the DESY Laboratory in Hamburg, died last March, just a few months after celebrating his 90th birthday. At that time, the Bulletin dedicated an article to him (Bulletin n°19-20/2002). Now, CERN has organised a Memorial Symposium for next Thursday 31 October, where you are cordially invited. This tribute will include the following speechs: L. Maiani : Welcome E. Lohrmann : Message from DESY H. Schopper : Willi Jentschke M. Veltman and D. Perkins : The Neutral Currents K. Johnsen : The ISR in Jentschke's time K. Winter : Some recollections of Jentschke The Memorial Symposium will take place in the Council Chamber, Thursday 31 October at 15 hrs. Drinks will be served at 17:30 hrs following the symposium.

  18. The 1956 CERN Symposium

    CERN Document Server

    Jarlskog, Cecilia

    2014-01-01

    CERN, currently the largest organization in the world for particle physics, was founded in 1954. Originally located in Meyrin, at the outskirts of the city of Geneva in Switzerland, it has with time extended into neighboring France. The Theoretical Study Division of CERN, however, was created already in 1952, i.e., before the official inauguration of CERN. It was situated in Copenhagen. Christian Møller [1] was appointed (part-time) as the Director and there were two full time senior staff members, Gunnar Källén and Ben R. Mottelson. While constructing buildings and accelerators were in progress, an international conference was organized by CERN in the city of Geneva. This “CERN Symposium on High Energy Accelerators and Pion Physics”, 11–23 June 1956, attracted about 250 participants from outside CERN, among them at least 18 Nobel Laureates or future Laureates. Unfortunately, the participants from CERN are not listed in the Proceedings [2]. The conference focused on measuring devices such as bubbl...

  19. The Orbital Debris Problem and the Challenges for Environment Remediation

    Science.gov (United States)

    Liou, J.-C.

    2014-01-01

    LEO debris population will continue to increase even with a good implementation of the commonly-adopted mitigation measures. The root-cause of the increase is catastrophic collisions involving large/massive intact objects (rocket bodies or spacecraft). The major mission-ending risks for most operational spacecraft, however, come from impacts with debris just above the threshold of the protection shields (5-mm to 1-cm). A solution-driven approach is to seek: Concepts for removal of massive intacts with high P(collision); Concepts capable of preventing collisions involving intacts; Concepts for removal of 5-mm to 1-cm debris; Enhanced impact protection shields for valuable space assets. Key questions for remediation consideration of orbital debris: What is the acceptable threat level? What are the mission objectives? What is the appropriate roadmap/timeframe for remediation? Support advanced technology development when an economically viable approach is identified. Address non-technical issues, such as policy, coordination, ownership, legal, and liability at the national and international levels.

  20. Behavior of explosion debris clouds

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    In the normal course of events the behavior of debris clouds created by explosions will be of little concern to the atomic energy industry. However, two situations, one of them actual and one postulated, exist where the rise and spread of explosion clouds can affect site operations. The actual occurrence would be the detonation of nuclear weapons and the resultant release and transport of radioactive debris across the various atomic energy installations. Although the activity of the diffusing cloud is not of biological concern, it may still be sufficiently above background to play havoc with the normal readings of sensitive monitoring instruments. If it were not known that these anomalous readings resulted from explosion debris, considerable time and expense might be required for on-site testing and tracing. Fortunately it is usually possible, with the use of meteorological data and forecasts, to predict when individual sites are affected by nuclear weapon debris effects. The formation rise, and diffusion of weapon clouds will be discussed. The explosion of an atomic reactor is the postulated situation. It is common practice in reactor hazard analysis to assume a combination of circumstances which might result in a nuclear incident with a release of material to the atmosphere. It is not within the scope of this report to examine the manifold plausibilities that might lead to an explosion or the possible methods of release of gaseous and/or particulates from such an occurrence. However, if the information of a cloud is assumed and some idea of its energy content is obtainable, estimates of the cloud behavior in the atmosphere can be made

  1. DebriSat - A Planned Laboratory-Based Satellite Impact Experiment for Breakup Fragment Characterization

    Science.gov (United States)

    Liou, J.-C.; Fitz-Coy, N.; Werremeyer, M.; Huynh, T.; Voelker, M.; Opiela, J.

    2012-01-01

    DebriSat is a planned laboratory ]based satellite hypervelocity impact experiment. The goal of the project is to characterize the orbital debris that would be generated by a hypervelocity collision involving a modern satellite in low Earth orbit (LEO). The DebriSat project will update and expand upon the information obtained in the 1992 Satellite Orbital Debris Characterization Impact Test (SOCIT), which characterized the breakup of a 1960 's US Navy Transit satellite. There are three phases to this project: the design and fabrication of an engineering model representing a modern, 50-cm/50-kg class LEO satellite known as DebriSat; conduction of a laboratory-based hypervelocity impact to catastrophically break up the satellite; and characterization of the properties of breakup fragments down to 2 mm in size. The data obtained, including fragment size, area ]to ]mass ratio, density, shape, material composition, optical properties, and radar cross ]section distributions, will be used to supplement the DoD fs and NASA fs satellite breakup models to better describe the breakup outcome of a modern satellite. Updated breakup models will improve mission planning, environmental models, and event response. The DebriSat project is sponsored by the Air Force fs Space and Missile Systems Center and the NASA Orbital Debris Program Office. The design and fabrication of DebriSat is led by University of Florida with subject matter experts f support from The Aerospace Corporation. The major milestones of the project include the complete fabrication of DebriSat by September 2013, the hypervelocity impact of DebriSat at the Air Force fs Arnold Engineering Development Complex in early 2014, and fragment characterization and data analyses in late 2014.

  2. Comparing two models for post-wildfire debris flow susceptibility mapping

    Science.gov (United States)

    Cramer, J.; Bursik, M. I.; Legorreta Paulin, G.

    2017-12-01

    Traditionally, probabilistic post-fire debris flow susceptibility mapping has been performed based on the typical method of failure for debris flows/landslides, where slip occurs along a basal shear zone as a result of rainfall infiltration. Recent studies have argued that post-fire debris flows are fundamentally different in their method of initiation, which is not infiltration-driven, but surface runoff-driven. We test these competing models by comparing the accuracy of the susceptibility maps produced by each initiation method. Debris flow susceptibility maps are generated according to each initiation method for a mountainous region of Southern California that recently experienced wildfire and subsequent debris flows. A multiple logistic regression (MLR), which uses the occurrence of past debris flows and the values of environmental parameters, was used to determine the probability of future debris flow occurrence. The independent variables used in the MLR are dependent on the initiation method; for example, depth to slip plane, and shear strength of soil are relevant to the infiltration initiation, but not surface runoff. A post-fire debris flow inventory serves as the standard to compare the two susceptibility maps, and was generated by LiDAR analysis and field based ground-truthing. The amount of overlap between the true locations where debris flow erosion can be documented, and where the MLR predicts high probability of debris flow initiation was statistically quantified. The Figure of Merit in Space (FMS) was used to compare the two models, and the results of the FMS comparison suggest that surface runoff-driven initiation better explains debris flow occurrence. Wildfire can breed conditions that induce debris flows in areas that normally would not be prone to them. Because of this, nearby communities at risk may not be equipped to protect themselves against debris flows. In California, there are just a few months between wildland fire season and the wet

  3. Mapping surface temperature variability on a debris-covered glacier with an unmanned aerial vehicle

    Science.gov (United States)

    Kraaijenbrink, P. D. A.; Litt, M.; Shea, J. M.; Treichler, D.; Koch, I.; Immerzeel, W.

    2016-12-01

    progresses, and the influence of ice on debris surface temperature reduces considerably. Many patterns are revealed that cannot be detected from the Landsat data, both on small spatial and temporal scales. The high detail the UAV-borne thermal imagery provides in time and space has great potential in the research of debris cover and its characteristics.

  4. Mining and Reclamation Technology Symposium

    Energy Technology Data Exchange (ETDEWEB)

    None Available

    1999-06-24

    The Mining and Reclamation Technology Symposium was commissioned by the Mountaintop Removal Mining/Valley Fill Environmental Impact Statement (EIS) Interagency Steering Committee as an educational forum for the members of the regulatory community who will participate in the development of the EIS. The Steering Committee sought a balanced audience to ensure the input to the regulatory community reflected the range of perspectives on this complicated and emotional issue. The focus of this symposium is on mining and reclamation technology alternatives, which is one of eleven topics scheduled for review to support development of the EIS. Others include hydrologic, environmental, ecological, and socio-economic issues.

  5. International Symposium on Unmanned Aerial Vehicles

    CERN Document Server

    Oh, Paul; Piegl, Les

    2009-01-01

    Unmanned Aircraft Systems (UAS) have seen unprecedented levels of growth during the last decade in both military and civilian domains. It is anticipated that civilian applications will be dominant in the future, although there are still barriers to be overcome and technical challenges to be met. Integrating UAS into, for example, civilian space, navigation, autonomy, see-detect-and-avoid systems, smart designs, system integration, vision-based navigation and training, to name but a few areas, will be of prime importance in the near future. This special volume is the outcome of research presented at the International Symposium on Unmanned Aerial Vehicles, held in Orlando, Florida, USA, from June 23-25, 2008, and presents state-of-the-art findings on topics such as: UAS operations and integration into the national airspace system; UAS navigation and control; micro-, mini-, small UAVs; UAS simulation testbeds and frameworks; UAS research platforms and applications; UAS applications. This book aims at serving as ...

  6. SPACE: Enhancing Life on Earth. Proceedings Report

    Science.gov (United States)

    Hobden, Alan (Editor); Hobden, Beverly (Editor); Bagley, Larry E. (Editor); Bolton, Ed (Editor); Campaigne, Len O. (Editor); Cole, Ron (Editor); France, Marty (Editor); Hand, Rich (Editor); McKinley, Cynthia (Editor); Zimkas, Chuck (Editor)

    1996-01-01

    The proceedings of the 12th National Space Symposium on Enhancing Life on Earth is presented. Technological areas discussed include: Space applications and cooperation; Earth sensing, communication, and navigation applications; Global security interests in space; and International space station and space launch capabilities. An appendices that include featured speakers, program participants, and abbreviation & acronyms glossary is also attached.

  7. Sizing of "Mother Ship and Catcher" Concepts for LEO Small Debris Capture

    Science.gov (United States)

    Bacon, John B.

    2009-01-01

    Most Low Earth Orbit (LEO) debris lies in a limited number of inclination "bands" associated with launch latitudes, or with specific useful orbit inclinations (such as polar orbits). Such narrow inclination bands generally have a uniform spread over all possible Right Ascensions of Ascending Node (RAANs), creating a different orbit plane for nearly every piece of debris. This complicates concept of rendezvous and capture for debris removal. However, a low-orbiting satellite will always phase in RAAN faster than debris objects in higher orbits at the same inclination, potentially solving the problem. Such a base can serve as a single space-based launch facility (a "mother ship") that can tend and then send tiny individual catcher devices for each debris object, as the facility drifts into the same RAAN as the higher object. This presentation will highlight characteristic system requirements of such an architecture, including structural and navigation requirements, power, mass and dV budgets for both the mother ship and the mass-produced common catcher devices that would clean out selected inclination bands. The altitude and inclination regime over which a band is to be cleared, the size distribution of the debris, and the inclusion of additional mission priorities all affect the sizing of the system. It is demonstrated that major LEO hazardous debris reductions can be realized in each band with a single LEO launch of a single mother ship, with simple attached catchers of total mass less than typical commercial LEO launch capability.

  8. Basal interstitial water pressure in laboratory debris flows over a rigid bed in an open channel

    Directory of Open Access Journals (Sweden)

    N. Hotta

    2012-08-01

    Full Text Available Measuring the interstitial water pressure of debris flows under various conditions gives essential information on the flow stress structure. This study measured the basal interstitial water pressure during debris flow routing experiments in a laboratory flume. Because a sensitive pressure gauge is required to measure the interstitial water pressure in shallow laboratory debris flows, a differential gas pressure gauge with an attached diaphragm was used. Although this system required calibration before and after each experiment, it showed a linear behavior and a sufficiently high temporal resolution for measuring the interstitial water pressure of debris flows. The values of the interstitial water pressure were low. However, an excess of pressure beyond the hydrostatic pressure was observed with increasing sediment particle size. The measured excess pressure corresponded to the theoretical excess interstitial water pressure, derived as a Reynolds stress in the interstitial water of boulder debris flows. Turbulence was thought to induce a strong shear in the interstitial space of sediment particles. The interstitial water pressure in boulder debris flows should be affected by the fine sediment concentration and the phase transition from laminar to turbulent debris flow; this should be the subject of future studies.

  9. The international environment UNISPACE '82 and the ITU: A relationship between orbit-spectrum resource allocation and orbital debris

    Science.gov (United States)

    Olmstead, D.

    1985-01-01

    The 1985 Space WARC will examine and potentially modify the current geostationary orbit spectrum resource allocation methodology. Discussions in this international political environment could likely associate the geostationary orbital debris issue with the politicized issue of orbit spectrum allocation.

  10. NEW DEBRIS DISKS IN NEARBY YOUNG MOVING GROUPS

    Energy Technology Data Exchange (ETDEWEB)

    Moór, A.; Kóspál, Á.; Ábrahám, P.; Kiss, Cs. [Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, P.O. Box 67, H-1525 Budapest (Hungary); Balog, Z.; Henning, Th. [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Csengeri, T. [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Juhász, A., E-mail: moor@konkoly.hu [Institute of Astronomy, Madingley Road, Cambridge CB3, OHA (United Kingdom)

    2016-08-01

    A significant fraction of nearby young moving group members harbor circumstellar debris dust disks. Due to their proximity and youth, these disks are attractive targets for studying the early evolution of debris dust and planetesimal belts. Here we present 70 and 160 μ m observations of 31 systems in the β Pic moving group, and in the Tucana–Horologium, Columba, Carina, and Argus associations, using the Herschel Space Observatory . None of these stars were observed at far-infrared wavelengths before. Our Herschel measurements were complemented by photometry from the WISE satellite for the whole sample, and by submillimeter/millimeter continuum data for one source, HD 48370. We identified six stars with infrared excess, four of them are new discoveries. By combining our new findings with results from the literature, we examined the incidence and general characteristics of debris disks around Sun-like members of the selected groups. With their dust temperatures of <45 K the newly identified disks around HD 38397, HD 48370, HD 160305, and BD-20 951 represent the coldest population within this sample. For HD 38397 and HD 48370, the emission is resolved in the 70 μ m Photodetector Array Camera and Spectrograph images, the estimated radius of these disks is ∼90 au. Together with the well-known disk around HD 61005, these three systems represent the highest mass end of the known debris disk population around young G-type members of the selected groups. In terms of dust content, they resemble the hypothesized debris disk of the ancient solar system.

  11. Symposium: What Is College English?

    Science.gov (United States)

    Bloom, Lynn Z.; White, Edward M.; Enoch, Jessica; Hawk, Byron

    2013-01-01

    This symposium explores the role(s) College English has (or has not) had in the scholarly work of four scholars. Lynn Bloom explores the many ways College English influenced her work and the work of others throughout their scholarly lives. Edward M. White examines four articles he has published in College English and draws connections between…

  12. SYMPOSIUM ON PLANT PROTEIN PHOSPHORYLATION

    Energy Technology Data Exchange (ETDEWEB)

    JOHN C WALKER

    2011-11-01

    Protein phosphorylation and dephosphorylation play key roles in many aspects of plant biology, including control of cell division, pathways of carbon and nitrogen metabolism, pattern formation, hormonal responses, and abiotic and biotic responses to environmental signals. A Symposium on Plant Protein Phosphorylation was hosted on the Columbia campus of the University of Missouri from May 26-28, 2010. The symposium provided an interdisciplinary venue at which scholars studying protein modification, as it relates to a broad range of biological questions and using a variety of plant species, presented their research. It also provided a forum where current international challenges in studies related to protein phosphorylation could be examined. The symposium also stimulated research collaborations through interactions and networking among those in the research community and engaged students and early career investigators in studying issues in plant biology from an interdisciplinary perspective. The proposed symposium, which drew 165 researchers from 13 countries and 21 States, facilitated a rapid dissemination of acquired knowledge and technical expertise regarding protein phosphorylation in plants to a broad range of plant biologists worldwide.

  13. Diversity in the Workplace. Symposium.

    Science.gov (United States)

    2002

    Three papers comprise this symposium on diversity in the workplace. "Factors That Assist and Barriers That Hinder the Success of Diversity Initiatives in Multinational Corporations" (Rose Mary Wentling) reports that factors that assisted in the success were classified under diversity department, human, and work environment; barriers were…

  14. Indian symposium reviews tsunami response

    Directory of Open Access Journals (Sweden)

    Paula Banerjee

    2005-07-01

    Full Text Available A symposium of academics and human rights activists organised by the Calcutta Research Group assessed the extent to which relief and rehabilitation initiatives in Tamil Nadu and the Andaman and Nicobar islands have recognised the rights of those affected to receive aid without discrimination based on caste, religion or gender.

  15. National symposium on food irradiation

    International Nuclear Information System (INIS)

    Beyers, M.; Brodrick, H.T.; Van Niekerk, W.C.A.

    1980-01-01

    This report contains proceedings of papers delivered at the national symposium on food irradiation held in Pretoria. The proceedings have been grouped into the following sections: general background; meat; agricultural products; marketing; and radiation facilities - cost and plant design. Each paper has been submitted separately to INIS. Tables listing irradiated food products cleared for human consumption in different countries are given

  16. 44th Aerospace Mechanisms Symposium

    Science.gov (United States)

    Boesiger, Edward A. (Compiler)

    2018-01-01

    The Aerospace Mechanisms Symposium (AMS) provides a unique forum for those active in the design, production and use of aerospace mechanisms. A major focus is the reporting of problems and solutions associated with the development and flight certification of new mechanisms.

  17. 2016 Gilbert W. Beebe symposium

    Science.gov (United States)

    The National Academies of Sciences, Engineering, and Medicine is hosting the 2016 Gilbert W. Beebe Symposium. Its focus will be on commemorating the 1986 Chernobyl nuclear reactor accident and discussing the achievements of 30 years of studies on the radiation health effects following the accident and future research directions.

  18. AAAI 1993 Fall Symposium Reports

    OpenAIRE

    Levinson, Robert; Epstein, Susan; Terveen, Loren; Bonasso, R. Peter; Miller, David P.; Bowyer, Kevin; Hall, Lawrence

    1994-01-01

    The Association for the Advancement of Artificial Intelligence held its 1993 Fall Symposium Series on October 22-24 in Raleigh, North Carolina. This article contains summaries of the six symposia that were conducted: Automated Deduction in Nonstandard Logics; Games: Planning and Learning; Human-Computer Collaboration: Reconciling Theory, Synthesizing Practice; Instantiating Intelligent Agents; and Machine Learning and Computer Vision: What, Why, and How?

  19. An In vitro Comparison of Apically Extruded Debris Using Reciproc, ProTaper Universal, Neolix and Hyflex in Curved Canals

    Science.gov (United States)

    Labbaf, Hossein; Nazari Moghadam, Kiumars; Shahab, Shahriar; Mohammadi Bassir, Mahshid; Fahimi, Mohammad Amin

    2017-01-01

    Introduction: As a consequence of root canal preparation, dentinal chips, irrigants and pulp remnants are extruded into preradicular space. This phenomenon may lead to post endodontic flare-ups. The purpose of this study was to compare the amount of extruded debris with four endodontic NiTi engine-driven systems. Methods and Materials: Sixty mesiobuccal roots of maxillary molars with 15-30˚ curvature were divided randomly into four groups (n=15). Each group was instrumented up to apical size of 25 using Reciproc, ProTaper Universal, Neolix and Hyflex. Bidistilled water was used as irrigant and extruded debris was collected in pre-weighted Eppendorf tubes. Tubes were stored in incubator for drying the debris. Extruded debris were weighted in electronic microbalance with accuracy of 0.0001 g. The raw data was analyzed with one way analysis of variance (ANOVA) and Tukey’s HSD post hoc test. Level of significance was set at 0.05. Results: The debris extrusion with Reciproc files was significantly higher than the other groups (P<0.05). Hyflex significantly extruded less debris than other files (P<0.05). There was no significant difference between ProTaper Universal and Neolix regarding the amount of extruded debris (P=0.98). Conclusion: All systems extruded debris during the instrumentation. Reciproc system significantly extruded more debris. Caution should be taken when interpreting the results of this study and applying it to the real clinical situation. PMID:28808456

  20. The VLT Opening Symposium

    Science.gov (United States)

    1999-02-01

    Scientists Meet in Antofagasta to Discuss Front-Line Astrophysics To mark the beginning of the VLT era, the European Southern Observatory is organizing a VLT Opening Symposium which will take place in Antofagasta (Chile) on 1-4 March 1999, just before the start of regular observations with the ESO Very Large Telescope on April 1, 1999. The Symposium occupies four full days and is held on the campus of the Universidad Catolica del Norte. It consists of plenary sessions on "Science in the VLT Era and Beyond" and three parallel Workshops on "Clusters of Galaxies at High Redshift" , "Star-way to the Universe" and "From Extrasolar Planets to Brown Dwarfs" . There will be many presentations of recent work at the major astronomical facilities in the world. The meeting provides a very useful forum to discuss the latest developments and, in this sense, contributes to the planning of future research with the VLT and other large telescopes. The symposium will be opened with a talk by the ESO Director General, Prof. Riccardo Giacconi , on "Paranal - an observatory for the 21st century". It will be followed by reports about the first scientific results from the main astronomical instruments on VLT UT1, FORS1 and ISAAC. The Symposium participants will see the VLT in operation during special visits to the Paranal Observatory. Press conferences are being arranged each afternoon to inform about the highlights of the conference. After the Symposium, there will be an Official Inauguration Ceremony at Paranal on 5 March Contributions from ESO ESO scientists will make several presentations at the Symposium. They include general reviews of various research fields as well as important new data and results from the VLT that show the great potential of this new astronomical facility. Some of the recent work is described in this Press Release, together with images and spectra of a large variety of objects. Note that all of these data will soon become publicly available via the VLT Archive

  1. IAEA symposium on international safeguards

    International Nuclear Information System (INIS)

    1999-01-01

    The eighth IAEA Symposium on International Safeguards was organized by the IAEA in cooperation with the Institute of Nuclear Materials Management and the European Safeguards Research and Development Association. It was attended by over 350 specialists and policy makers in the field of nuclear safeguards and verification from more than 50 countries and organizations. The purpose of the Symposium was to foster a broad exchange of information on concepts and technologies related to important developments in the areas of international safeguards and security. For the first time in the history of the symposia, the IAEA is issuing proceedings free of charge to participants on CD-ROM. The twenty-two plenary, technical, and poster sessions featured topics related to technological and policy aspects from national, regional and global perspectives. The theme of the Symposium: Four Decades of Development - Safeguarding into the New Millennium set the stage for the commemoration of a number of significant events in the annals of safeguards. 1997 marked the Fortieth Anniversary of the IAEA, the Thirtieth Anniversary of the Tlatelolco Treaty, and the Twentieth Anniversary of the Department of Safeguards Member State Support Programmes. There were special events and noted presentations featuring these anniversaries and giving the participants an informative retrospective view of safeguards development over the past four decades. The proceedings of this symposium provide the international community with a comprehensive view of where nuclear safeguards and verification stood in 1997 in terms of the growing demands and expectations. The Symposium offered thoughtful perspectives on where safeguards are headed within the broader context of verification issues. As the world of international nuclear verification looks towards the next millennium, the implementation of the expanding and strengthened safeguards system presents formidable challenges

  2. Preservation of Near-Earth Space for Future Generations

    Science.gov (United States)

    Simpson, John A.

    2007-05-01

    List of contributors; Preface; Part I. Introduction: 1. Introduction J. A. Simpson; Part II. Defining the Problem: 2. The Earth satellite population: official growth and constituents Nicholas L. Johnson; 3. The current and future environment: an overall assessment Donald J. Kessler; 4. The current and future space debris environment as assessed in Europe Dietrich Rex; 5. Human survivability issues in the low Earth orbit space debris environment Bernard Bloom; 6. Protecting the space environment for astronomy Joel R. Primack; 7. Effects of space debris on commercial spacecraft - the RADARSAT example H. Robert Warren and M. J. Yelle; 8. Potential effects of the space debris environment on military space systems Albert E. Reinhardt; Part III. Mitigation of and Adaptation to the Space Environment: Techniques and Practices: 9. Precluding post-launch fragmentation of delta stages Irvin J. Webster and T. Y. Kawamura; 10. US international and interagency cooperation in orbital debris Daniel V. Jacobs; 11. ESA concepts for space debris mitigation and risk reduction Heiner Klinkrad; 12. Space debris: how France handles mitigation and adaptation Jean-Louis Marcé; 13. Facing seriously the issue of protection of the outer space environment Qi Yong Liang; 14. Space debris - mitigation and adaptation U. R. Rao; 15. Near Earth space contamination and counteractions Vladimir F. Utkin and S. V. Chekalin; 16. The current and future space debris environment as assessed in Japan Susumu Toda; 17. Orbital debris minimization and mitigation techniques Joseph P. Loftus Jr, Philip D. Anz-Meador and Robert Reynolds; Part IV. Economic Issues: 18. In pursuit of a sustainable space environment: economic issues in regulating space debris Molly K. Macauley; 19. The economics of space operations: insurance aspects Christopher T. W. Kunstadter; Part V. Legal Issues: 20. Environmental treatymaking: lessons learned for controlling pollution of outer space Winfried Lang; 21. Regulation of orbital

  3. Numerical investigation of debris materials prior to debris flow hazards using satellite images

    Science.gov (United States)

    Zhang, N.; Matsushima, T.

    2018-05-01

    The volume of debris flows occurred in mountainous areas is mainly affected by the volume of debris materials deposited at the valley bottom. Quantitative evaluation of debris materials prior to debris flow hazards is important to predict and prevent hazards. At midnight on 7th August 2010, two catastrophic debris flows were triggered by the torrential rain from two valleys in the northern part of Zhouqu City, NW China, resulting in 1765 fatalities and huge economic losses. In the present study, a depth-integrated particle method is adopted to simulate the debris materials, based on 2.5 m resolution satellite images. In the simulation scheme, the materials are modeled as dry granular solids, and they travel down from the slopes and are deposited at the valley bottom. The spatial distributions of the debris materials are investigated in terms of location, volume and thickness. Simulation results show good agreement with post-disaster satellite images and field observation data. Additionally, the effect of the spatial distributions of the debris materials on subsequent debris flows is also evaluated. It is found that the spatial distributions of the debris materials strongly influence affected area, runout distance and flow discharge. This study might be useful in hazard assessments prior to debris flow hazards by investigating diverse scenarios in which the debris materials are unknown.

  4. Autogenic dynamics of debris-flow fans

    Science.gov (United States)

    van den Berg, Wilco; de Haas, Tjalling; Braat, Lisanne; Kleinhans, Maarten

    2015-04-01

    Alluvial fans develop their semi-conical shape by cyclic avulsion of their geomorphologically active sector from a fixed fan apex. These cyclic avulsions have been attributed to both allogenic and autogenic forcings and processes. Autogenic dynamics have been extensively studied on fluvial fans through physical scale experiments, and are governed by cyclic alternations of aggradation by unconfined sheet flow, fanhead incision leading to channelized flow, channel backfilling and avulsion. On debris-flow fans, however, autogenic dynamics have not yet been directly observed. We experimentally created debris-flow fans under constant extrinsic forcings, and show that autogenic dynamics are a fundamental intrinsic process on debris-flow fans. We found that autogenic cycles on debris-flow fans are driven by sequences of backfilling, avulsion and channelization, similar to the cycles on fluvial fans. However, the processes that govern these sequences are unique for debris-flow fans, and differ fundamentally from the processes that govern autogenic dynamics on fluvial fans. We experimentally observed that backfilling commenced after the debris flows reached their maximum possible extent. The next debris flows then progressively became shorter, driven by feedbacks on fan morphology and flow-dynamics. The progressively decreasing debris-flow length caused in-channel sedimentation, which led to increasing channel overflow and wider debris flows. This reduced the impulse of the liquefied flow body to the flow front, which then further reduced flow velocity and runout length, and induced further in-channel sedimentation. This commenced a positive feedback wherein debris flows became increasingly short and wide, until the channel was completely filled and the apex cross-profile was plano-convex. At this point, there was no preferential transport direction by channelization, and the debris flows progressively avulsed towards the steepest, preferential, flow path. Simultaneously

  5. Sampling supraglacial debris thickness using terrestrial photogrammetry

    Science.gov (United States)

    Nicholson, Lindsey; Mertes, Jordan

    2017-04-01

    The melt rate of debris-covered ice differs to that of clean ice primarily as a function of debris thickness. The spatial distribution of supraglacial debris thickness must therefore be known in order to understand how it is likely to impact glacier behaviour, and meltwater contribution to local hydrological resources and global sea level rise. However, practical means of determining debris cover thickness remain elusive. In this study we explore the utility of terrestrial photogrammetry to produce high resolution, scaled and texturized digital terrain models of debris cover exposures above ice cliffs as a means of quantifying and characterizing debris thickness. Two Nikon D5000 DSLRs with Tamron 100mm lenses were used to photograph a sample area of the Ngozumpa glacier in the Khumbu Himal of Nepal in April 2016. A Structure from Motion workflow using Agisoft Photoscan software was used to generate a surface models with <10cm resolution. A Trimble Geo7X differential GPS with Zephyr antenna, along with a local base station, was used to precisely measure marked ground control points to scale the photogrammetric surface model. Measurements of debris thickness along the exposed cliffline were made from this scaled model, assuming that the ice surface at the debris-ice boundary is horizontal, and these data are compared to 50 manual point measurements along the same clifftops. We conclude that sufficiently high resolution photogrammetry, with precise scaling information, provides a useful means to determine debris thickness at clifftop exposures. The resolution of the possible measurements depends on image resolution, the accuracy of the ground control points and the computational capacity to generate centimetre scale surface models. Application of such techniques to sufficiently high resolution imagery from UAV-borne cameras may offer a powerful means of determining debris thickness distribution patterns over debris covered glacier termini.

  6. A Real-Time Systems Symposium Preprint.

    Science.gov (United States)

    1983-09-01

    Real - Time Systems Symposium Preprint Interim Tech...estimate of the occurence of the error. Unclassii ledSECUqITY CLASSIF’ICA T" NO MI*IA If’ inDI /’rrd erter for~~ble. ’Corrputnqg A REAL - TIME SYSTEMS SYMPOSIUM...ABSTRACT This technical report contains a preprint of a paper accepted for presentation at the REAL - TIME SYSTEMS SYMPOSIUM, Arlington,

  7. The Fabulous Four Debris Disks

    Science.gov (United States)

    Werner, Michael; Stapelfeldt, Karl

    2004-09-01

    This program is a comprehensive study of the four bright debris disks that were spatially resolved by IRAS: Beta Pictoris, Epsilon Eridani, Fomalhaut, and Vega. All SIRTF instruments and observing modes will be used. The program has three major objectives: (1) Study of the disk spatial structure from MIPS and IRAC imaging; (2) Study of the dust grain composition using the IRS and MIPS SED mode; and (3) companion searches using IRAC. The data from this program should lead to a detailed understanding of these four systems, and will provide a foundation for understanding all of the debris disks to be studied with SIRTF. Images and spectra will be compared with models for disk structure and dust properties. Dynamical features indicative of substellar companions' effects on the disks will be searched for. This program will require supporting observations of PSF stars, some of which have been included explicitly. In the majority of cases, the spectral observations require a preferred orientation to align the slits along the disk position angles. Detector saturation issues are still being worked for this program, and will lead to AOR modifications in subsequent submissions. The results from this program will be analyzed collaboratively by the IRAC, IRS, and MIPS teams and by general GTOs Jura and Werner.

  8. Simulation of Micron-Sized Debris Populations in Low Earth Orbit

    Science.gov (United States)

    Xu, Y.-L.; Matney, M.; Liou, J.-C.; Hyde, J. L.; Prior, T. G.

    2010-01-01

    The update of ORDEM2000, the NASA Orbital Debris Engineering Model, to its new version . ORDEM2010, is nearly complete. As a part of the ORDEM upgrade, this paper addresses the simulation of micro-debris (greater than 10 micron and smaller than 1 mm in size) populations in low Earth orbit. The principal data used in the modeling of the micron-sized debris populations are in-situ hypervelocity impact records, accumulated in post-flight damage surveys on the space-exposed surfaces of returned spacecrafts. The development of the micro-debris model populations follows the general approach to deriving other ORDEM2010-required input populations for various components and types of debris. This paper describes the key elements and major steps in the statistical inference of the ORDEM2010 micro-debris populations. A crucial step is the construction of a degradation/ejecta source model to provide prior information on the micron-sized objects (such as orbital and object-size distributions). Another critical step is to link model populations with data, which is rather involved. It demands detailed information on area-time/directionality for all the space-exposed elements of a shuttle orbiter and damage laws, which relate impact damage with the physical properties of a projectile and impact conditions such as impact angle and velocity. Also needed are model-predicted debris fluxes as a function of object size and impact velocity from all possible directions. In spite of the very limited quantity of the available shuttle impact data, the population-derivation process is satisfactorily stable. Final modeling results obtained from shuttle window and radiator impact data are reasonably convergent and consistent, especially for the debris populations with object-size thresholds at 10 and 100 micron.

  9. Debris flows: behavior and hazard assessment

    Science.gov (United States)

    Iverson, Richard M.

    2014-01-01

    Debris flows are water-laden masses of soil and fragmented rock that rush down mountainsides, funnel into stream channels, entrain objects in their paths, and form lobate deposits when they spill onto valley floors. Because they have volumetric sediment concentrations that exceed 40 percent, maximum speeds that surpass 10 m/s, and sizes that can range up to ~109 m3, debris flows can denude slopes, bury floodplains, and devastate people and property. Computational models can accurately represent the physics of debris-flow initiation, motion and deposition by simulating evolution of flow mass and momentum while accounting for interactions of debris' solid and fluid constituents. The use of physically based models for hazard forecasting can be limited by imprecise knowledge of initial and boundary conditions and material properties, however. Therefore, empirical methods continue to play an important role in debris-flow hazard assessment.

  10. Silicon Photonics for Space Communications

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal is aimed to address level two "Optical Communication and Navigation" needs within the "5.0 Communications, Navigation, and Orbital Debris Tracking and...

  11. Ninth international symposium on radiopharmacology

    International Nuclear Information System (INIS)

    1995-01-01

    The goal of this Symposium is to provide a forum for those international scientists involved in applying the principles of pharmacology and radiation biology to the development of agents for the diagnosis and treatment of disease. The program will highlight state-of-the-art progress in the development of those agents used in conjunction with some form of radiation such as radiopharmaceuticals, radiopaques, photo- and radiosensitizing drugs, and neutron capture agents. An underlying pharmacokinetic parameter associated with all these agents is the need for site-specific delivery to an organ or tumor. Therefore, a major goal of the symposium will be to address those pharmacologic principles for targeting molecules to specific tissue sites. Accordingly, session themes will include receptor-mediated processes, membrane transporters, antibody interactions, metabolic trapping, and oligonucleotide-antisense mechanisms

  12. Memorial Symposium for Victor Weisskopf

    CERN Multimedia

    2002-01-01

    Victor 'Viki' Weisskopf, former Director General of CERN from 1961 to 1965, passed away five months ago. At that time, the Bulletin dedicated its coverpage to this brilliant physicist (19-20/2002). Now, CERN has organised a Memorial Symposium for next Tuesday 17 September, where you are cordially invited. This tribute will include the following speechs: L. Maiani: Welcome J. D. Jackson: Highlights from the career and scientific works of Victor F. Weisskopf M. Hine and K. Johnsen: Working with Viki at CERN M. Jacob: Knowledge and Wonder A member of Viki's family: Reminiscences. The Memorial Symposium will take place in the Main Auditorium at 15h. Drinks will be served in Pas Perdus at 17h 30.

  13. Ninth international symposium on radiopharmacology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The goal of this Symposium is to provide a forum for those international scientists involved in applying the principles of pharmacology and radiation biology to the development of agents for the diagnosis and treatment of disease. The program will highlight state-of-the-art progress in the development of those agents used in conjunction with some form of radiation such as radiopharmaceuticals, radiopaques, photo- and radiosensitizing drugs, and neutron capture agents. An underlying pharmacokinetic parameter associated with all these agents is the need for site-specific delivery to an organ or tumor. Therefore, a major goal of the symposium will be to address those pharmacologic principles for targeting molecules to specific tissue sites. Accordingly, session themes will include receptor-mediated processes, membrane transporters, antibody interactions, metabolic trapping, and oligonucleotide-antisense mechanisms.

  14. Conceptualizing an economically, legally, and politically viable active debris removal option

    Science.gov (United States)

    Emanuelli, M.; Federico, G.; Loughman, J.; Prasad, D.; Chow, T.; Rathnasabapathy, M.

    2014-11-01

    It has become increasingly clear in recent years that the issue of space debris, particularly in low-Earth orbit, can no longer be ignored or simply mitigated. Orbital debris currently threatens safe space flight for both satellites and humans aboard the International Space Station. Additionally, orbital debris might impact Earth upon re-entry, endangering human lives and damaging the environment with toxic materials. In summary, orbital debris seriously jeopardizes the future not only of human presence in space, but also of human safety on Earth. While international efforts to mitigate the current situation and limit the creation of new debris are useful, recent studies predicting debris evolution have indicated that these will not be enough to ensure humanity's access to and use of the near-Earth environment in the long-term. Rather, active debris removal (ADR) must be pursued if we are to continue benefiting from and conducting space activities. While the concept of ADR is not new, it has not yet been implemented. This is not just because of the technical feasibility of such a scheme, but also because of the host of economic, legal/regulatory, and political issues associated with debris remediation. The costs of ADR are not insignificant and, in today's restrictive fiscal climate, are unlikely/to be covered by any single actor. Similarly, ADR concepts bring up many unresolved questions about liability, the protection of proprietary information, safety, and standards. In addition, because of the dual use nature of ADR technologies, any venture will necessarily require political considerations. Despite the many unanswered questions surrounding ADR, it is an endeavor worth pursuing if we are to continue relying on space activities for a variety of critical daily needs and services. Moreover, we cannot ignore the environmental implications that an unsustainable use of space will imply for life on Earth in the long run. This paper aims to explore some of these

  15. Memorial symposium for Victor Weisskopf.

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    A memorial symposium for Victor Weisskopf, CERN Director-General from 1961 to 1965, was held at CERN on 17 September 2002. Photo 01: L. Maiani: Welcome.Photo 02: J. D. Jackson: Highlights from the career and scientific works of Victor F. Weisskopf.Photos 05 09: M. Hine and K. Johnsen: Working with Viki at CERN.Photo 10: M. Jacob: Knowledge and Wonder.Photo 14: K. Worth (Viki's daughter): Reminiscences.

  16. Scandinavian Symposium on Reactor Waste

    International Nuclear Information System (INIS)

    1981-09-01

    More than 100 delegates forom the Scandinavian countries were gathered for a symposium on September 14-16 1981 at Kungaelv Sweden to discuss nuclear reactor waste. The organisation for the handling of radioactive waste at different countries was presented and the principles of radioactive safety were discussed. The planning of the deposition and storage of waste was described. The proceedings are reproduced on some twenty papers, a number of them written in English. (G.B.)

  17. Symposium on Nuclear Energy. Proceedings

    International Nuclear Information System (INIS)

    1981-01-01

    The energy problem poses a big challenge to a developing country like the Philippines. The development of renewable energy sources is not enough. Aware then of the limitations of these energy sources, in spite of arguments against nuclear energy we have no other recourse but to go nuclear. This symposium emphasizes the importance of energy development to attain the country's progress and discusses the pros and economics of nuclear power. (RTD)

  18. National symposium on food irradiation

    International Nuclear Information System (INIS)

    1979-10-01

    This report contains abstracts of papers delivered at the National symposium on food irradiation held in Pretoria. The abstracts have been grouped into the following sections: General background, meat, agricultural products, marketing and radiation facilities - cost and plant design. Each abstract has been submutted separately to INIS. Tables listing irradiated food products cleared for human consumption in different countries are given as well as a table listing those irradiated food items that have been cleared in South Africa

  19. Rapporteurs report of the symposium

    International Nuclear Information System (INIS)

    Myerscough, Dan

    2014-01-01

    The objective of the symposium was to share current practice, experiences and innovations within the management of contaminated metallic radioactive material. The symposium was a forum for: Learning about current practices, Highlight strategic issues related to metals recycling, Exchange of experiences, Discussion of innovative and new techniques and needs for improvements, Developing and maintenance of networks in the area of metals recycling. The aim was to bring together operators, regulators, decision makers, scientists, consultants, contractors and other stakeholders. A short introduction by representatives from Studsvik, IAEA and OECD/NEA started the symposium followed by presentations by invited speakers from international organisations. Seven topical sessions covered issues relating to: 1 - Regulations and recommendations: - International recommendations and national legislation, - Application of regulations, - Regulator views; 2 - Minimising waste amounts: - Experience in minimising the generation of waste in the form of radioactive or potentially radioactive metals, - Activities to minimise the waste volumes for disposal; 3 - Characterisation and categorisation of metals to be recycled; 4 - Decontamination of metals for clearance; 5 - Melting of metals for clearance, reuse or volume reduction; 6 - Best practice in management of metals for clearance and recycling; 7 - Sustainability and public acceptance. Each session contained three to five presentations and group discussions. Each session was concluded with a short analysis of the presentations and the outcome of the group discussions. Conclusions of each session and outcome of the group discussions were presented on a Summing up the third day. The symposium also held a poster session with topics as above. This report provides a short summary of the various presentations and discussions concentrating on the key messages and outcomes of the sessions

  20. Crafoord Symposium on Magnetospheric Physics : Achievements and Prospects

    CERN Document Server

    Fälthammar, C-G

    1990-01-01

    This book contains the proceedings of the 1989 Crafoord Symposium organized by the Royal Swedish Academy of Sciences. The scientific field for the Crafoord Prize of 1989 was decided in 1988 by the Academy to be Magnetospheric Physics. On September 27,1989 the Academy awarded the 1989 Crafoord Prize to Professor J. A. Van Allen, Iowa City, USA "for his pioneer work in space research, in particular for the discovery of the high energy charged particles that are trapped in the Earth's magnetic field and form the radiation belts -often called the Van Allen belts - around the Earth". The subject for the Crafoord Symposium, which was held on September 28-29 at the Royal Swedish Academy of Sciences in Stockholm, was Magnetospheric Physics, Achievements and Prospects. Some seventy of the world's leading scientists in magnetospheric physics (see list of participants) were invited to the Symposium. The program contained only invited papers. After the ?resentation of the Crafoord Prize Laureate, Prof. J . A. Van Allen, ...

  1. The Extragalactic Infrared Background and Its Cosmological Implications: IAU Symposium 204

    Science.gov (United States)

    Harwit, Martin

    2001-01-01

    Conference was held in Manchester, England, United Kingdom, in 2000 August. The Proceedings will be edited by Martin Harwit of Cornell and Michael Hauser of the Space Telescope Science Institute and will appear in the IAU Symposium Series, which is published by the Astronomical Society of the Pacific.

  2. 11. European cosmic ray symposium held at Balatonfuered, Hungary, August 21-27, 1988

    International Nuclear Information System (INIS)

    1988-08-01

    The biannual Symposium includes all aspects of cosmic ray research. The scientific programme was organized under three main headings: Cosmic rays in the heliosphere, Cosmic rays in the interstellar and extragalactic space, Properties of high-energy interactions as studied by cosmic rays. Selected short communications out of 114 contributed papers were indexed separately for the INIS database. (R.P.)

  3. RICIS Software Engineering 90 Symposium: Aerospace Applications and Research Directions Proceedings Appendices

    Science.gov (United States)

    1990-01-01

    Papers presented at RICIS Software Engineering Symposium are compiled. The following subject areas are covered: flight critical software; management of real-time Ada; software reuse; megaprogramming software; Ada net; POSIX and Ada integration in the Space Station Freedom Program; and assessment of formal methods for trustworthy computer systems.

  4. Crispy Cracks Symposium Explores Crispness and Water Management

    NARCIS (Netherlands)

    Hamer, R.J.; Vliet, van T.

    2008-01-01

    This article provides an overview of the first international symposium on crispness creation and retention. The symposium, entitled, ¿Crispy Cracks Symposium,¿ was organized by Cereals & Europe and TI Food and Nutrition. The symposium contained three sessions: 1) Crispiness¿The Fundamentals; 2)

  5. Symposium on Differential Geometry and Differential Equations

    CERN Document Server

    Berger, Marcel; Bryant, Robert

    1987-01-01

    The DD6 Symposium was, like its predecessors DD1 to DD5 both a research symposium and a summer seminar and concentrated on differential geometry. This volume contains a selection of the invited papers and some additional contributions. They cover recent advances and principal trends in current research in differential geometry.

  6. Conserving biodiversity on native rangelands: Symposium proceedings

    Science.gov (United States)

    Daniel W. Uresk; Greg L. Schenbeck; James T. O' Rourke

    1997-01-01

    These proceedings are the result of a symposium, "Conserving biodiversity on native rangelands" held on August 17, 1995 in Fort Robinson State Park, NE. The purpose of this symposium was to provide a forum to discuss how elements of rangeland biodiversity are being conserved today. We asked, "How resilient and sustainable are rangeland systems to the...

  7. 4th International Language Management Symposium

    Czech Academy of Sciences Publication Activity Database

    Prošek, Martin

    2016-01-01

    Roč. 77, č. 3 (2016), s. 233-240 ISSN 0037-7031. [international language management symposium] Institutional support: RVO:68378092 Keywords : language management theory * international language symposium * language management Subject RIV: AI - Linguistics OBOR OECD: Linguistics Impact factor: 0.625, year: 2016

  8. Coal economics and taxation discussed at symposium

    Energy Technology Data Exchange (ETDEWEB)

    1978-06-01

    Some of the highlights from the Symposium on Coal Economics and Taxation Symposium, Regina Saskatchewan May 7-9, 1978, sponsored by the Coal Association of Canada are presented. Investment, provincial policy, sources of funds, uncertainty, tax policies, and operating costs are discussed.

  9. 6th European symposium on uroradiology

    International Nuclear Information System (INIS)

    Bujlov, V.M.

    1999-01-01

    Materials of the 6th European symposium on uroradiology held in Strasbourg (France) in September, 1998. Symposium topics included problems of radiological diagnosis of kidneys, renovascular hypertension, man and woman sterility, pelvis organs of men and women, functional studies of lower urinary tract, pediatric and interventional uroradiology. Great attention is paid to magnetic resonance tomography, ultrasonography and conventional biomedical radiography [ru

  10. A Search for Debris Disks Around Variable Pulsars

    Science.gov (United States)

    Shannon, Ryan; Cordes, J.; Lazio, J.; Kramer, M.; Lyne, A.

    2009-01-01

    After a supernova explosion, a modest amount of material will fall back and form a disk surrounding the resultant neutron star. This material can aggregate into rocky debris and the disk can be stable for the entire 10 million year lifetime of a canonical (non-recycled) radio pulsar. Previously, we developed a model that unifies the different classes of radio variability observed in many older pulsars. In this model, rocky material migrates inwards towards the neutron star and is ablated inside the pulsar magnetosphere. This material alters the electrodynamics in the magnetosphere which can cause the observed quiescent and bursting states observed in nulling pulsars, intermittent pulsars, and rotating radio transients. With this model in mind, we observed three nulling pulsars and one intermittent pulsar that are good candidates to host debris disks detectable by the Spitzer IRAC. Here we report how our IRAC observations constrain disk geometry, with particular emphasis on configurations that can provide the in-fall rate to cause the observed radio variability. We place these observations in the context of other searches for debris disks around neutron stars, which had studied either very young or very old (recycled) pulsars. By observing older canonical pulsars, all major classes of radio pulsars have been observed, and we can assess the presence of debris disks as a function of pulsar type. This work is based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech.

  11. POST Earthquake Debris Management — AN Overview

    Science.gov (United States)

    Sarkar, Raju

    Every year natural disasters, such as fires, floods, earthquakes, hurricanes, landslides, tsunami, and tornadoes, challenge various communities of the world. Earthquakes strike with varying degrees of severity and pose both short- and long-term challenges to public service providers. Earthquakes generate shock waves and displace the ground along fault lines. These seismic forces can bring down buildings and bridges in a localized area and damage buildings and other structures in a far wider area. Secondary damage from fires, explosions, and localized flooding from broken water pipes can increase the amount of debris. Earthquake debris includes building materials, personal property, and sediment from landslides. The management of this debris, as well as the waste generated during the reconstruction works, can place significant challenges on the national and local capacities. Debris removal is a major component of every post earthquake recovery operation. Much of the debris generated from earthquake is not hazardous. Soil, building material, and green waste, such as trees and shrubs, make up most of the volume of earthquake debris. These wastes not only create significant health problems and a very unpleasant living environment if not disposed of safely and appropriately, but also can subsequently impose economical burdens on the reconstruction phase. In practice, most of the debris may be either disposed of at landfill sites, reused as materials for construction or recycled into useful commodities Therefore, the debris clearance operation should focus on the geotechnical engineering approach as an important post earthquake issue to control the quality of the incoming flow of potential soil materials. In this paper, the importance of an emergency management perspective in this geotechnical approach that takes into account the different criteria related to the operation execution is proposed by highlighting the key issues concerning the handling of the construction

  12. POST Earthquake Debris Management - AN Overview

    Science.gov (United States)

    Sarkar, Raju

    Every year natural disasters, such as fires, floods, earthquakes, hurricanes, landslides, tsunami, and tornadoes, challenge various communities of the world. Earthquakes strike with varying degrees of severity and pose both short- and long-term challenges to public service providers. Earthquakes generate shock waves and displace the ground along fault lines. These seismic forces can bring down buildings and bridges in a localized area and damage buildings and other structures in a far wider area. Secondary damage from fires, explosions, and localized flooding from broken water pipes can increase the amount of debris. Earthquake debris includes building materials, personal property, and sediment from landslides. The management of this debris, as well as the waste generated during the reconstruction works, can place significant challenges on the national and local capacities. Debris removal is a major component of every post earthquake recovery operation. Much of the debris generated from earthquake is not hazardous. Soil, building material, and green waste, such as trees and shrubs, make up most of the volume of earthquake debris. These wastes not only create significant health problems and a very unpleasant living environment if not disposed of safely and appropriately, but also can subsequently impose economical burdens on the reconstruction phase. In practice, most of the debris may be either disposed of at landfill sites, reused as materials for construction or recycled into useful commodities Therefore, the debris clearance operation should focus on the geotechnical engineering approach as an important post earthquake issue to control the quality of the incoming flow of potential soil materials. In this paper, the importance of an emergency management perspective in this geotechnical approach that takes into account the different criteria related to the operation execution is proposed by highlighting the key issues concerning the handling of the construction

  13. Design of full scale debris washing system

    International Nuclear Information System (INIS)

    Taylor, M.L.; Dosani, M.A.; Wentz, J.A.; Patkar, A.N.; Barkley, N.P.

    1992-01-01

    Since 1987, IT Environmental Programs Inc. (ITEP, a subsidiary of International Technology Corporation) in conjunction with EPA/RREL in Cincinnati, Ohio, have been developing and conducting bench scale and pilot scale testing of a transportable debris washing system which can be used on-site for the decontamination of debris. During the initial phase of the debris decontamination project, a series of bench scale tests were performed in the laboratory to assess the ability of the system to remove contaminants from debris and to facilitate selection of the most efficient surfactant solution. Five nonionic, non-toxic, low foaming, surfactant solution (BG-5, MC-2000, LF-330, BB-100, and L-433) were selected for an experimental evaluation to determine their capacity to solubilize and remove contaminants from the surfaces of corroded steel places. The pieces of corroded steel were coated with a heavy grease mixture prepared in the laboratory and these pieces of debris were placed in a bench scale spray tank on a metal tray and subjected in a high-pressure spray for each surfactant solution for 15 minutes. At the end of the spray cycle, The tray was transferred to a second bench scale system, a high-turbulence wash tank, where the debris was washed for 30 minutes with the same surfactant solution as the used in the spray tank. After the was cycle was completed, the tray was removed from the wash tank and the debris was allowed to air-dry. Before and after treatment, surface-wipe samples were obtained from each of the six pieces of debris and were analyzed for oil and graese. Based on the results, BG-5 was selected as the solution best suited for cleaning grease-laden, metallic debris. 2 refs

  14. Development of debris resistant bottom end piece

    International Nuclear Information System (INIS)

    Lee, Jae Kyung; Sohn, Dong Seong; Yim, Jeong Sik; Hwang, Dae Hyun; Song, Kee Nam; Oh, Dong Seok; Rhu, Ho Sik; Lee, Chang Woo; Kim, Seong Soo; Oh, Jong Myung

    1993-12-01

    Debris-related fuel failures have been identified as one of the major causes of fuel failures. In order to reduce the possibility of debris-related fuel failures, it is necessary to develop Debris-Resistant Bottom End Piece. For this development, mechanical strength test and pressure drop test were performed, and the test results were analyzed. And the laser cutting, laser welding and electron beam welding technology, which were the core manufacturing technology of DRBEP, were developed. Final design were performed, and the final drawing and specifications were prepared. The prototype of DRBEP was manufactured according to the developed munufacturing procedure. (Author)

  15. Laser ignition of traumatically embedded firework debris.

    Science.gov (United States)

    Taylor, C R

    1998-01-01

    The Q-switched ruby laser (QSRL) has a good track record for traumatic tattoo removal. An unusual case of QSRL-treatment of a traumatic tattoo composed of firework debris is presented. A young man's traumatic tattoo, composed of firework debris, underwent QSRL ablation at 4-7 J/cm2 (pulse width 5 mm; duration 20 ns). Each test pulse produced visible sparks and focal projectile ejection of skin with pox-like scar formation. Caution is advised when using the QSRL for the treatment of traumatic tattoos composed of potentially combustible debris.

  16. Review of current activities to model and measure the orbital debris environment in low-earth orbit

    Science.gov (United States)

    Reynolds, R. C.

    A very active orbital debris program is currently being pursued at the NASA/Johnson Space Center (JSC), with projects designed to better define the current environment, to project future environments, to model the processes contributing to or constraining the growth of debris in the environment, and to gather supporting data needed to improve the understanding of the orbital debris problem and the hazard it presents to spacecraft. This paper is a review of the activity being conducted at JSC, by NASA, Lockheed Engineering and Sciences Company, and other support contractors, and presents a review of current activity, results of current research, and a discussion of directions for future development.

  17. International symposium 'Energetics 2004'. Symposium proceedings. Book 1

    International Nuclear Information System (INIS)

    2004-01-01

    The holding of this Symposium was initiated by ZEMAK - Macedonian Energy Association that for the last tens of years established itself in the national and international scientific and professional circles as a competent association of professionals with the main goal to follow, promote and improve the energy sector in the country. Having in mind the fact that the power energy sector as a fundamental sector plays a main role in the development and the improvement of the rest of the industry, and in the same time has a tremendous impact on the sustainable development of the entire economy of a country, power energy sector in fact has the paramount importance in the business environment of our country. Thus, ZEMAK has historically important role as a responsible and permanent driver, promoter and initiator for resolving of all-important questions directly or indirectly interconnected with the power energy sector in the country, and therefore the entire economy in the country as well. Following the past, ZEMAK had and would always have needs of organizing national and international symposiums and workshops as a panel where directly at one place national and international power energy experts could initiate, debate and resolve all up-to-date questions in the present energy sector in Macedonia, could analyze the modern world trends in the energy sector and try to find appropriate models for their application for further development and improvement of the energy sector in our country. This international symposium has the main goal to concentrate on a single place everybody who has power energy as a permanent preoccupation and/or vocation and professional interest. To aggregate on one place various experts, from the Academy and Universities, from the business circles and companies who are preoccupied with power energy directly or indirectly in their everyday life and work. During the Symposium more than 90 scientific and/or professional papers were presented and discussed

  18. 14. European cosmic ray symposium. Symposium program and abstracts

    International Nuclear Information System (INIS)

    1994-08-01

    The abstracts of the 14. European Cosmic Ray Symposium are presented. The papers cover a large variety of topics in cosmic ray physics, both from the theoretical and the experimental point of view. Sun physics, and the effects on the inner heliosphere, the composition, and the properties of the primary and secondary cosmic radiation, galactic acceleration and the results of accelerator physics relevant to cosmic radiation physics, and the description and the results of large detector systems are presented. 63 items are indexed for INIS database. (K.A.)

  19. International symposium 'Energetics 2004'. Symposium proceedings. Book 2

    International Nuclear Information System (INIS)

    2004-01-01

    The holding of this Symposium was initiated by ZEMAK - Macedonian Energy Association that for the last tens of years established itself in the national and international scientific and professional circles as a competent association of professionals with the main goal to follow, promote and improve the energy sector in the country. Having in mind the fact that the power energy sector as a fundamental sector plays a main role in the development and the improvement of the rest of the industry, and in the same time has a tremendous impact on the sustainable development of the entire economy of a country, power energy sector in fact has the paramount importance in the business environment of our country. Thus, ZEMAK has historically important role as a responsible and permanent driver, promoter and initiator for resolving of all-important questions directly or indirectly interconnected with the power energy sector in the country, and therefore the entire economy in the country as well. Following the past, ZEMAK had and would always have needs of organizing national and international symposiums and workshops as a panel where directly at one place national and international power energy experts could initiate, debate and resolve all up-to-date questions in the present energy sector in Macedonia, could analyze the modern world trends in the energy sector and try to find appropriate models for their application for further development and improvement of the energy sector in our country. This international symposium has the main goal to concentrate on a single place everybody who has power energy as a permanent preoccupation and/or vocation and professional interest. To aggregate on one place various experts, from the Academy and Universities, from the business circles and companies who are preoccupied with power energy directly or indirectly in their everyday life and work. During the Symposium more than 90 scientific and/or professional papers were presented and discussed

  20. Development of debris-resistant bottom end piece

    International Nuclear Information System (INIS)

    Sohn, Dong Seong; Lee, Jae Kyung; Hwang, Dae Hyun; Yim, Jung Sik; Song, Kee Nam; Oh, Dong Seok; Im, Hyun Tae

    1993-01-01

    Debris-related fuel failures has been identified to be one of the major causes of fuel failures recently occured in nuclear power plants. In order to reduce the possibility of debris-related fuel failures, it is necessary to prevent the debris from reaching to fuel rods. In this regard, it is important to develop Debris-Resistant Bottom End Piece. (Author)

  1. The composition of matter symposium honouring Johannes Geiss on the occasion of his 80th birthday

    CERN Document Server

    Gloeckler, George; Mason, G M

    2007-01-01

    This volume consists of papers developed from a joint ACE/ISSI symposium on the "Composition of Matter" honoring the occasion of Johannes Geiss's 80th birthday. The reader will find new insights into the composition of solar-system and galactic matter and fractionation processes affecting samples of this matter. These findings are based on measurements by recent space instruments, ground-based studies, and theoretical advances. The five symposium sessions reflect the areas of research presented in this book: linking primordial to solar composition, planetary samples, solar sources and fractionation processes, interstellar gas, and cosmic rays. The structure of the volume at hand largely follows the structure of the symposium. It includes almost all of the overview and invited papers and many of the contributed ones.

  2. International Symposium of Scientists for Nuclear test Stopping

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    Problems discussed at International Symposium of Scientists for Nuclear Test Stopping in July 1986 in Moscow were considered. Scientists discussed complex of possible measures directed at strengthening of peace supporting mechanism, spoke in support of prohibition of all nuclear weapon tests. Necessity of measures preventing the weapon delivery to space, construction of the regime of using cosmic equipment exclusively for peace was noted. Attention was paid to the problem of control for test stopping (by means of sattelites and seismic methods), cooperation establishment between the USSR Academy of Sciences and the Council for the protection of the USA Natural Resources

  3. Debris Examination Using Ballistic and Radar Integrated Software

    Science.gov (United States)

    Griffith, Anthony; Schottel, Matthew; Lee, David; Scully, Robert; Hamilton, Joseph; Kent, Brian; Thomas, Christopher; Benson, Jonathan; Branch, Eric; Hardman, Paul; hide

    2012-01-01

    The Debris Examination Using Ballistic and Radar Integrated Software (DEBRIS) program was developed to provide rapid and accurate analysis of debris observed by the NASA Debris Radar (NDR). This software provides a greatly improved analysis capacity over earlier manual processes, allowing for up to four times as much data to be analyzed by one-quarter of the personnel required by earlier methods. There are two applications that comprise the DEBRIS system: the Automated Radar Debris Examination Tool (ARDENT) and the primary DEBRIS tool.

  4. Structural debris experiments at operation MILL RACE

    International Nuclear Information System (INIS)

    Rempel, J.R.; Beck, J.E.; McKee, R.G.

    1983-01-01

    Structural debris patterns as determined by the mechanisms of building collapse under airblast loading have been studied experimentally at MILL RACE, White Sands, NM. Three near full-size buildings were instrumented to observe deflections, accelerations and air pressures and exposed to two different regimes of incident blast pressure produced by HE simulating 1 kt, viz., 10 and 3 psi; after the shot enough wall debris was located and identified to provide estimates of debris movement. Two of the test buildings were unreinforced, load-bearing masonry, one located at each of the two incident overpressures. The third building was made of reinforced concrete panels and was exposed to approximately 25 psi. Preliminary estimates of the effect of arching on debris energy and distribution are presented

  5. TMI defueling project fuel debris removal system

    International Nuclear Information System (INIS)

    Burdge, B.

    1992-01-01

    The three mile Island Unit 2 (TMI-2) pressurized water reactor loss-of-coolant accident on March 28, 1979, presented the nuclear community with many challenging remediation problems; most importantly, the removal of the fission products within the reactor containment vessel. To meet this removal problem, an air-lift system (ALS) can be used to employ compressed air to produce the motive force for transporting debris. Debris is separated from the transport stream by gravity separation. The entire method does not rely on any moving parts. Full-scale testing of the ALS at the Idaho National Engineering Laboratory (INEL) has demonstrated the capability of transporting fuel debris from beneath the LCSA into a standard fuel debris bucket at a minimum rate of 230 kg/min

  6. Comparison of an Inductance In-Line Oil Debris Sensor and Magnetic Plug Oil Debris Sensor

    Science.gov (United States)

    Dempsey, Paula J.; Tuck, Roger; Showalter, Stephen

    2012-01-01

    The objective of this research was to compare the performance of an inductance in-line oil debris sensor and magnetic plug oil debris sensor when detecting transmission component health in the same system under the same operating conditions. Both sensors were installed in series in the NASA Glenn Spiral Bevel Gear Fatigue Rig during tests performed on 5 gear sets (pinion/gear) when different levels of damage occurred on the gear teeth. Results of this analysis found both the inductance in-line oil debris sensor and magnetic plug oil debris sensor have benefits and limitations when detecting gearbox component damage.

  7. Marine debris: global and regional impacts

    OpenAIRE

    Torres N,Daniel; Berguño B,Jorge

    2011-01-01

    A synthesis on the Marine Debris problem is given upon de basis of the general knowledge on the matter as well as that obtained at Cape Shirreff, Livingston Island, South Shetland, Antarctica. It is suggested to improve the database on marine debris through permanent scientific research as well as with monitoring activities. It is necessary to coordinate key groups to apply strategies to identify types, sources, amount, interactions and socio-economic aspects of this global and regional probl...

  8. 6th Asian Physics Symposium

    International Nuclear Information System (INIS)

    2016-01-01

    Preface: The 6th Asian Physics Symposium 2015 (APS 2015) The 6th Asian Physics Symposium 2015 (APS 2015) is organized by the Physics Department, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, in collaboration with HFI (Indonesian Physical Society), PAPSI (Physics and Applied Physics Society of Indonesia), HANI (Indonesian Nuclear Scientist Society), HRMI (Indonesian Material Research Society), HAGI (Indonesian Geophysicist Society) - West Java Chapter, and HFMBI (Indonesian Medical Physicist and Biophysicist Society). APS 2015 is aimed at providing a forum of scientific communication and interaction among distinguished scientists working in physics and its related fields. In this scientific event the latest research will be presented, and state-of-the-art developments in the field discussed, to help to guide our future research directions. It is also designed to offer the opportunity for young Indonesian scientists and students to make direct contacts with well-known scientists abroad and thereby foster the existing research collaborations and extend international research networking for the future. The scope of research presented and discussed in this symposium covers theoretical high energy physics, materials sciences and technology, biophysics and medical physics, nuclear science and engineering, earth and planetary sciences, computational physics, instrumentation and measurement, physics education, and interdisciplinary physics. The program of APS 2016 features 6 invited talks and 208 contributed oral presentations, which come from 7 different countries: Japan, South Korea, Singapore, Malaysia, Iraq, Ethiopia, and Indonesia. All papers have been reviewed after they are presented in this event. Selected papers are published in this Institute of Physics (IoP) Conference Series. Finally, I would like to express my sincere appreciation to all of authors for their valuable contributions and also to the members of the committee for

  9. Postdetonation nuclear debris for attribution.

    Science.gov (United States)

    Fahey, A J; Zeissler, C J; Newbury, D E; Davis, J; Lindstrom, R M

    2010-11-23

    On the morning of July 16, 1945, the first atomic bomb was exploded in New Mexico on the White Sands Proving Ground. The device was a plutonium implosion device similar to the device that destroyed Nagasaki, Japan, on August 9 of that same year. Recently, with the enactment of US public law 111-140, the "Nuclear Forensics and Attribution Act," scientists in the government and academia have been able, in earnest, to consider what type of forensic-style information may be obtained after a nuclear detonation. To conduct a robust attribution process for an exploded device placed by a nonstate actor, forensic analysis must yield information about not only the nuclear material in the device but about other materials that went into its construction. We have performed an investigation of glassed ground debris from the first nuclear test showing correlations among multiple analytical techniques. Surprisingly, there is strong evidence, obtainable only through microanalysis, that secondary materials used in the device can be identified and positively associated with the nuclear material.

  10. Aarhus Regenerative Orthopaedics Symposium (AROS)

    DEFF Research Database (Denmark)

    Foldager, Casper B.; Bendtsen, Michael; Berg, Lise C.

    2016-01-01

    to musculoskeletal pain and disability. The Aarhus Regenerative Orthopaedics Symposium (AROS) 2015 was motivated by the need to address regenerative challenges in an ageing population by engaging clinicians, basic scientists, and engineers. In this position paper, we review our contemporary understanding of societal......, patient-related, and basic science-related challenges in order to provide a reasoned roadmap for the future to deal with this compelling and urgent healthcare problem. © 2017 The Author(s). Published by Taylor & Francis on behalf of the Nordic Orthopedic Federation....

  11. Third symposium on underground mining

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-01-01

    The Third Symposium on Underground Mining was held at the Kentucky Fair and Exposition Center, Louisville, KY, October 18--20, 1977. Thirty-one papers have been entered individually into EDB and ERA. The topics covered include mining system (longwall, shortwall, room and pillar, etc.), mining equipment (continuous miners, longwall equipment, supports, roof bolters, shaft excavation equipment, monitoring and control systems. Maintenance and rebuilding facilities, lighting systems, etc.), ventilation, noise abatement, economics, accidents (cost), dust control and on-line computer systems. (LTN)

  12. Stanford Lepton-Photon Symposium

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1989-10-15

    With CERN's new LEP electron-positron collider poised to make its physics debut, the physics at the 14th International Symposium on Lepton and Photon Interactions, held at Stanford from 7-12 August, featured a ripple of new results on the Z and W bosons, the carriers of respectively the electrically neutral and charged components of the weak nuclear force. These new W and Z results, combined with refined measurements in other sectors, have interesting implications for expected but as yet unseen particles, notably the sixth ('top') quark.

  13. International Ocean Symposium (IOS) 1996; Kokusai kaiyo symposium 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-18

    This is a proceedings of the International Ocean Symposium 1996. On the first day of the symposium, the following were given with a theme `The Ocean, Can She Save Us`: Underwater research and future of mankind as a commemorative speech; The ocean, can she save us -- trying to discover the true figure of the ocean as a keynote speech. Panel discussion was held on The global environment and the infinite potential of the ocean. On the second day, an approach was made mostly from a cultural aspect with a theme `The Ocean and the Japanese.` The following were given: Human links between east and west as a commemorative speech; The ocean and Japanese culture as a keynote speech; Civilization spanning across oceans as a panel discussion. The Japanese have been developing their individual technologies in shipbuilding, shipping, and ocean development, have been raised by Mother Ocean, and have lived together. Ocean has been supplying humans food, water, oxygen, marine routes, and even dream and hope. The environmental pollution is the result of the human greediness. It is fear and friendship between humans and ocean that can save humans and ocean.

  14. Herschel Observations of Gas and Dust in the Unusual 49 Ceti Debris Disk

    NARCIS (Netherlands)

    Roberge, A.; Kamp, I.; Montesinos, B.; Dent, W. R. F.; Meeus, G.; Donaldson, J. K.; Olofsson, J.; Moor, A.; Augereau, J. -C.; Howard, C.; Eiroa, C.; Thi, W. -F.; Ardila, D. R.; Sandell, G.; Woitke, P.

    2013-01-01

    We present far-IR/sub-mm imaging and spectroscopy of 49 Ceti, an unusual circumstellar disk around a nearby young A1V star. The system is famous for showing the dust properties of a debris disk, but the gas properties of a low-mass protoplanetary disk. The data were acquired with the Herschel Space

  15. Global analysis of anthropogenic debris ingestion by sea turtles.

    Science.gov (United States)

    Schuyler, Qamar; Hardesty, Britta Denise; Wilcox, Chris; Townsend, Kathy

    2014-02-01

    Ingestion of marine debris can have lethal and sublethal effects on sea turtles and other wildlife. Although researchers have reported on ingestion of anthropogenic debris by marine turtles and implied incidences of debris ingestion have increased over time, there has not been a global synthesis of the phenomenon since 1985. Thus, we analyzed 37 studies published from 1985 to 2012 that report on data collected from before 1900 through 2011. Specifically, we investigated whether ingestion prevalence has changed over time, what types of debris are most commonly ingested, the geographic distribution of debris ingestion by marine turtles relative to global debris distribution, and which species and life-history stages are most likely to ingest debris. The probability of green (Chelonia mydas) and leatherback turtles (Dermochelys coriacea) ingesting debris increased significantly over time, and plastic was the most commonly ingested debris. Turtles in nearly all regions studied ingest debris, but the probability of ingestion was not related to modeled debris densities. Furthermore, smaller, oceanic-stage turtles were more likely to ingest debris than coastal foragers, whereas carnivorous species were less likely to ingest debris than herbivores or gelatinovores. Our results indicate oceanic leatherback turtles and green turtles are at the greatest risk of both lethal and sublethal effects from ingested marine debris. To reduce this risk, anthropogenic debris must be managed at a global level. © 2013 The Authors. Conservation Biology published by Wiley Periodicals, Inc., on behalf of the Society for Conservation Biology.

  16. Active Debris Removal mission design in Low Earth Orbit

    Science.gov (United States)

    Martin, Th.; Pérot, E.; Desjean, M.-Ch.; Bitetti, L.

    2013-03-01

    Active Debris Removal (ADR) aims at removing large sized intact objects ― defunct satellites, rocket upper-stages ― from space crowded regions. Why? Because they constitute the main source of the long-term debris environment deterioration caused by possible future collisions with fragments and worse still with other intact but uncontrolled objects. In order to limit the growth of the orbital debris population in the future (referred to as the Kessler syndrome), it is now highly recommended to carry out such ADR missions, together with the mitigation measures already adopted by national agencies (such as postmission disposal). At the French Space Agency, CNES, and in the frame of advanced studies, the design of such an ADR mission in Low Earth Orbit (LEO) is under evaluation. A two-step preliminary approach has been envisaged. First, a reconnaissance mission based on a small demonstrator (˜500 kg) rendezvousing with several targets (observation and in-flight qualification testing). Secondly, an ADR mission based on a larger vehicle (inherited from the Orbital Transfer Vehicle (OTV) concept) being able to capture and deorbit several preselected targets by attaching a propulsive kit to these targets. This paper presents a flight dynamics level tradeoff analysis between different vehicle and mission concepts as well as target disposal options. The delta-velocity, times, and masses required to transfer, rendezvous with targets and deorbit are assessed for some propelled systems and propellant less options. Total mass budgets are then derived for two end-to-end study cases corresponding to the reconnaissance and ADR missions mentioned above.

  17. A globally complete map of supraglacial debris cover and a new toolkit for debris cover research

    Science.gov (United States)

    Herreid, Sam; Pellicciotti, Francesca

    2017-04-01

    A growing canon of literature is focused on resolving the processes and implications of debris cover on glaciers. However, this work is often confined to a handful of glaciers that were likely selected based on criteria optimizing their suitability to test a specific hypothesis or logistical ease. The role of debris cover in a glacier system is likely to not go overlooked in forthcoming research, yet the magnitude of this role at a global scale has not yet been fully described. Here, we present a map of debris cover for all glacierized regions on Earth including the Greenland Ice Sheet using 30 m Landsat data. This dataset will begin to open a wider context to the high quality, localized findings from the debris-covered glacier research community and help inform large-scale modeling efforts. A global map of debris cover also facilitates analysis attempting to isolate first order geomorphological and climate controls of supraglacial debris production. Furthering the objective of expanding the inclusion of debris cover in forthcoming research, we also present an under development suite of open-source, Python based tools. Requiring minimal and often freely available input data, we have automated the mapping of: i) debris cover, ii) ice cliffs, iii) debris cover evolution over the Landsat era and iv) glacier flow instabilities from altered debris structures. At the present time, debris extent is the only globally complete quantity but with the expanding repository of high quality global datasets and further tool development minimizing manual tasks and computational cost, we foresee all of these tools being applied globally in the near future.

  18. The fifth Finnish national aerosol symposium

    International Nuclear Information System (INIS)

    Mikkanen, P.; Haemeri, K.; Kauppinen, E.

    1993-01-01

    The Fifth Finnish Aerosol Symposium was held June 1-3, 1993. Symposium is jointly organized by FAAR, Aerosol Technology Group of Technical Research Centre of Finland and Helsinki University, Department of Physics. Aerosols, the suspensions of solid and liquid particles and gases, are receiving increasing importance in many areas of science and technology. These include industrial hygiene, ambient and indoor air pollution, pollution control technologies, cloud physics, nuclear safety engineering, combustion science and engineering, clean manufacturing technologies and material processing. The importance of aerosol issues during the development of advanced fuel conversion and material processing technologies can be realized when looking at the numerous papers presented on these topics at the Symposium

  19. 6th interventional MRI symposium. Abstracts

    International Nuclear Information System (INIS)

    2006-01-01

    The ongoing progress in the field of interventional MRI and the great success of our last symposium 2004 in Boston have stimulated us to organize the 6th Interventional MRI Symposium to be held September 15-16, 2006 in Leipzig. This meeting will highlight ground-breaking research as well as cutting-edge reports from many groups. The symposium also provides a forum to network with leaders and innovators in the field. Session topics are: intraoperative MRI, vascular applications, targeted drug delivery, cryotherapy, thermometry, pulse sequences, LITT, percutaneous procedures, navigation, robotics, focused ultrasound. (uke)

  20. 10th German nuclear law symposium

    International Nuclear Information System (INIS)

    Koch, H.J.; Rossnagel, A.

    2000-01-01

    This 10th symposium on nuclear law in Germany was held eight years after the 9th symposium. Due to the change of government after the last general elections, there had been a turnaround in Germany's energy policy. 'Phasing out nuclear energy' was the major strategy of the new Federal Government. The topics of the papers presented at the symposium therefore focus on: a new time frame for NPP shutdown and termination of operating licences; ensuring the safe operation of nuclear power plants for the remaining operating periods; new concepts for radwaste management and ultimate disposal. (orig./CB) [de

  1. 6{sup th} interventional MRI symposium. Abstracts

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    The ongoing progress in the field of interventional MRI and the great success of our last symposium 2004 in Boston have stimulated us to organize the 6th Interventional MRI Symposium to be held September 15-16, 2006 in Leipzig. This meeting will highlight ground-breaking research as well as cutting-edge reports from many groups. The symposium also provides a forum to network with leaders and innovators in the field. Session topics are: intraoperative MRI, vascular applications, targeted drug delivery, cryotherapy, thermometry, pulse sequences, LITT, percutaneous procedures, navigation, robotics, focused ultrasound. (uke)

  2. Annual Symposium in Electronics Packaging

    CERN Document Server

    1991-01-01

    Each May, the Continuing Education Division of the T.J.Watson School of Engineering, Applied Science and Technology at the State University of New York at Binghamton sponsors an Annual Symposium in Electronics Packaging in cooperation with local professional societies (IEEE, ASME, SME, IEPS) and UnlPEG (the University-Industry Partnership for Economic Growth.) Each volume of this Electronics Packaging Forum series is based on the the preceding Symposium, with Volume Two based on the 1990 presentations. The Preface to Volume One included a brief definition of the broad scope of the electronics packaging field with some comments on why it has recently assumed such a more prominent priority for research and development. Those remarks will not be repeated here; at this point it is assumed that the reader is a professional in the packaging field, or possibly a student of one of the many academic disciplines which contribute to it. It is worthwhile repeating the series objectives, however, so the reader will be cle...

  3. 2015 International Symposium in Statistics

    CERN Document Server

    2016-01-01

    This proceedings volume contains eight selected papers that were presented in the International Symposium in Statistics (ISS) 2015 On Advances in Parametric and Semi-parametric Analysis of Multivariate, Time Series, Spatial-temporal, and Familial-longitudinal Data, held in St. John’s, Canada from July 6 to 8, 2015. The main objective of the ISS-2015 was the discussion on advances and challenges in parametric and semi-parametric analysis for correlated data in both continuous and discrete setups. Thus, as a reflection of the theme of the symposium, the eight papers of this proceedings volume are presented in four parts. Part I is comprised of papers examining Elliptical t Distribution Theory. In Part II, the papers cover spatial and temporal data analysis. Part III is focused on longitudinal multinomial models in parametric and semi-parametric setups. Finally Part IV concludes with a paper on the inferences for longitudinal data subject to a challenge of important covariates selection from a set of large num...

  4. DRAGONS - A Micrometeoroid and Orbital Debris Impact Sensor

    Science.gov (United States)

    Liou, J. -C.; Corsaro, R.; Giovane, F.; Anderson, C.; Sadilek, A.; Burchell, M.; Hamilton, J.

    2015-01-01

    The Debris Resistive/Acoustic Grid Orbital Navy-NASA Sensor (DRAGONS) is intended to be a large area impact sensor for in situ measurements of micrometeoroids and orbital debris (MMOD) in the millimeter or smaller size regime. These MMOD particles are too small to be detected by ground-based radars and optical telescopes, but are still large enough to be a serious safety concern for human space activities and robotic missions in the low Earth orbit (LEO) region. The nominal detection area of a DRAGONS unit is 1 m2, consisting of several independently operated panels. The approach of the DRAGONS design is to combine different particle impact detection principles to maximize information that can be extracted from detected events. After more than 10 years of concept and technology development, a 1 m2 DRAGONS system has been selected for deployment on the International Space Station (ISS) in August 2016. The project team achieved a major milestone when the Preliminary Design Review (PDR) was completed in May 2015. Once deployed on the ISS, this multi-year mission will provide a unique opportunity to demonstrate the MMOD detection capability of the DRAGONS technologies and to collect data to better define the small MMOD environment at the ISS altitude.

  5. Debris filtering effectiveness and pressure drop tests of debris resistance-bottom end piece

    International Nuclear Information System (INIS)

    Chung, Moon Ki; Song, Chul Hwa; Chung, Heung June; Won, Soon Yeun; Cho, Young Ro; Kim, Bok Deuk

    1992-03-01

    In this final report, described are the test conditions and test procedures for the debris filtering effectiveness and pressure drop tests for developing the Debris Resistance-Bottom End Piece (DR-BEP). And the test results are tabulated for later evaluation. (Author)

  6. Data Acquisition, Management, and Analysis in Support of the Audiology and Hearing Conservation and the Orbital Debris Program Office

    Science.gov (United States)

    Dicken, Todd

    2012-01-01

    My internship at Johnson Space Center, Houston TX comprised of working simultaneously in the Space Life Science Directorate (Clinical Services Branch, SD3) in Audiology and Hearing Conservation and in the Astromaterials Research and Exploration Sciences Directorate in the Orbital Debris Program Office (KX). The purpose of the project done to support the Audiology and Hearing Conservation Clinic (AuHCon) is to organize and analyze auditory test data that has been obtained from tests conducted onboard the International Space Station (ISS) and in Johnson Space Center's clinic. Astronauts undergo a special type of auditory test called an On-Orbit Hearing Assessment (OOHA), which monitors hearing function while crewmembers are exposed to noise and microgravity during long-duration spaceflight. Data needed to be formatted to assist the Audiologist in studying, analyzing and reporting OOHA results from all ISS missions, with comparison to conventional preflight and post-flight audiometric test results of crewmembers. Orbital debris is the #1 threat to manned spacecraft; therefore NASA is investing in different measurement techniques to acquire information on orbital debris. These measurements are taken with telescopes in different parts of the world to acquire brightness variations over time, from which size, rotation rates and material information can be determined for orbital debris. Currently many assumptions are taken to resolve size and material from observed brightness, therefore a laboratory (Optical Measurement Center) is used to simulate the space environment and acquire information of known targets suited to best model the orbital debris population. In the Orbital Debris Program Office (ODPO) telescopic data were acquired and analyzed to better assess the orbital debris population.

  7. Bi-objective optimization of a multiple-target active debris removal mission

    Science.gov (United States)

    Bérend, Nicolas; Olive, Xavier

    2016-05-01

    The increasing number of space debris in Low-Earth Orbit (LEO) raises the question of future Active Debris Removal (ADR) operations. Typical ADR scenarios rely on an Orbital Transfer Vehicle (OTV) using one of the two following disposal strategies: the first one consists in attaching a deorbiting kit, such as a solid rocket booster, to the debris after rendezvous; with the second one, the OTV captures the debris and moves it to a low-perigee disposal orbit. For multiple-target ADR scenarios, the design of such a mission is very complex, as it involves two optimization levels: one for the space debris sequence, and a second one for the "elementary" orbit transfer strategy from a released debris to the next one in the sequence. This problem can be seen as a Time-Dependant Traveling Salesman Problem (TDTSP) with two objective functions to minimize: the total mission duration and the total propellant consumption. In order to efficiently solve this problem, ONERA has designed, under CNES contract, TOPAS (Tool for Optimal Planning of ADR Sequence), a tool that implements a Branch & Bound method developed in previous work together with a dedicated algorithm for optimizing the "elementary" orbit transfer. A single run of this tool yields an estimation of the Pareto front of the problem, which exhibits the trade-off between mission duration and propellant consumption. We first detail our solution to cope with the combinatorial explosion of complex ADR scenarios with 10 debris. The key point of this approach is to define the orbit transfer strategy through a small set of parameters, allowing an acceptable compromise between the quality of the optimum solution and the calculation cost. Then we present optimization results obtained for various 10 debris removal scenarios involving a 15-ton OTV, using either the deorbiting kit or the disposal orbit strategy. We show that the advantage of one strategy upon the other depends on the propellant margin, the maximum duration allowed

  8. Mixed debris treatment at the Idaho National Engineering Laboratory (INEL)

    International Nuclear Information System (INIS)

    Garcia, E.C.; Porter, C.L.; Wallace, M.T.

    1993-01-01

    August 18, 1992 the Environmental Protection Agency (EPA) published the final revised treatment standards for hazardous debris, including mixed debris. (1) Whereas previous standards had been concentration based, the revised standards are performance based. Debris must be treated prior to land disposal, using specific technologies from one or more of the following families of debris treatment technologies: Extraction, destruction, or immobilization. Seventeen specific technologies with generic application are discussed in the final rule. The existing capabilities and types of debris at the INEL were scrubbed against the debris rule to determine an overall treatment strategy. Seven types of debris were identified: combustible, porous, non-porous, inherently hazardous, HEPA filters, asbestos contaminated, and reactive metals contaminated debris. With the exception of debris contaminated with reactive metals treatment can be achieved utilizing existing facilities coupled with minor modifications

  9. Mixed debris treatment at the Idaho National Engineering Laboratory (INEL)

    International Nuclear Information System (INIS)

    Garcia, E.C.; Porter, C.L.; Wallace, M.T.

    1993-01-01

    August 18, 1992 the EPA published the final revised treatment standards for hazardous debris, including mixed debris. Whereas previous standards had been concentration based, the revised standards are performance based. Debris must be treated prior to land disposal, using specific technologies from one or more of the following families of debris treatment technologies: Extraction, destruction, or immobilization. Seventeen specific technologies with generic application are discussed in the final rule. The existing capabilities and types of debris at the INEL were evaluated against the debris rule to determine an overall treatment strategy for the INEL. Seven types of debris were identified: Combustible, porous, non-porous, inherently hazardous, HEPA filters, asbestos contaminated, and reactive metals contaminated debris. With the exception of debris contaminated with reactive metals treatment can be achieved utilizing existing facilities coupled with minor modifications

  10. Thermal-hydraulic and characteristic models for packed debris beds

    International Nuclear Information System (INIS)

    Mueller, G.E.; Sozer, A.

    1986-12-01

    APRIL is a mechanistic core-wide meltdown and debris relocation computer code for Boiling Water Reactor (BWR) severe accident analyses. The capabilities of the code continue to be increased by the improvement of existing models. This report contains information on theory and models for degraded core packed debris beds. The models, when incorporated into APRIL, will provide new and improved capabilities in predicting BWR debris bed coolability characteristics. These models will allow for a more mechanistic treatment in calculating temperatures in the fluid and solid phases in the debris bed, in determining debris bed dryout, debris bed quenching from either top-flooding or bottom-flooding, single and two-phase pressure drops across the debris bed, debris bed porosity, and in finding the minimum fluidization mass velocity. The inclusion of these models in a debris bed computer module will permit a more accurate prediction of the coolability characteristics of the debris bed and therefore reduce some of the uncertainties in assessing the severe accident characteristics for BWR application. Some of the debris bed theoretical models have been used to develop a FORTRAN 77 subroutine module called DEBRIS. DEBRIS is a driver program that calls other subroutines to analyze the thermal characteristics of a packed debris bed. Fortran 77 listings of each subroutine are provided in the appendix

  11. Symposium on high spin phenomena in nuclei

    International Nuclear Information System (INIS)

    1979-10-01

    Separate abstracts were prepared for 44 of the papers given at this symposium. Six other papers have already been cited in ERA; these papers can be located by reference to the entry CONF-790323 - in the Report Number Index

  12. Proceedings of the 1994 nuclear simulation symposium

    Energy Technology Data Exchange (ETDEWEB)

    Laughton, P J [ed.; Atomic Energy of Canada Ltd., Chalk River, ON (Canada). Chalk River Nuclear Labs.

    1994-12-31

    This symposium on nuclear simulation included sessions on reactor physics, on thermalhydraulics, and on fuel and fuel channels of CANDU type reactors. The individual papers have all been abstracted separately.

  13. Symposium on unsaturated flow and transport modeling

    International Nuclear Information System (INIS)

    Arnold, E.M.; Gee, G.W.; Nelson, R.W.

    1982-09-01

    This document records the proceedings of a symposium on flow and transport processes in partially saturated groundwater systems, conducted at the Battelle Seattle Research Center on March 22-24, 1982. The symposium was sponsored by the US Nuclear Regulatory Commission for the purpose of assessing the state-of-the-art of flow and transport modeling for use in licensing low-level nuclear waste repositories in partially saturated zones. The first day of the symposium centered around research in flow through partially saturated systems. Papers were presented with the opportunity for questions following each presentation. In addition, after all the talks, a formal panel discussion was held during which written questions were addressed to the panel of the days speakers. The second day of the Symposium was devoted to solute and contaminant transport in partially saturated media in an identical format. Individual papers are abstracted

  14. Symposium on unsaturated flow and transport modeling

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, E.M.; Gee, G.W.; Nelson, R.W. (eds.)

    1982-09-01

    This document records the proceedings of a symposium on flow and transport processes in partially saturated groundwater systems, conducted at the Battelle Seattle Research Center on March 22-24, 1982. The symposium was sponsored by the US Nuclear Regulatory Commission for the purpose of assessing the state-of-the-art of flow and transport modeling for use in licensing low-level nuclear waste repositories in partially saturated zones. The first day of the symposium centered around research in flow through partially saturated systems. Papers were presented with the opportunity for questions following each presentation. In addition, after all the talks, a formal panel discussion was held during which written questions were addressed to the panel of the days speakers. The second day of the Symposium was devoted to solute and contaminant transport in partially saturated media in an identical format. Individual papers are abstracted.

  15. CUBE (Computer Use By Engineers) symposium abstracts

    International Nuclear Information System (INIS)

    Ruminer, J.J.

    1978-07-01

    This report presents the abstracts for the CUBE (Computer Use by Engineers) Symposium, October 4, through 6, 1978. Contributors are from Lawrence Livermore Laboratory, Los Alamos Scientific Laboratory, and Sandia Laboratories

  16. Prevalence of marine debris in marine birds from the North Atlantic.

    Science.gov (United States)

    Provencher, Jennifer F; Bond, Alexander L; Hedd, April; Montevecchi, William A; Muzaffar, Sabir Bin; Courchesne, Sarah J; Gilchrist, H Grant; Jamieson, Sarah E; Merkel, Flemming R; Falk, Knud; Durinck, Jan; Mallory, Mark L

    2014-07-15

    Marine birds have been found to ingest plastic debris in many of the world's oceans. Plastic accumulation data from necropsies findings and regurgitation studies are presented on 13 species of marine birds in the North Atlantic, from Georgia, USA to Nunavut, Canada and east to southwest Greenland and the Norwegian Sea. Of the species examined, the two surface plungers (great shearwaters Puffinus gravis; northern fulmars Fulmarus glacialis) had the highest prevalence of ingested plastic (71% and 51%, respectively). Great shearwaters also had the most pieces of plastics in their stomachs, with some individuals containing as many of 36 items. Seven species contained no evidence of plastic debris. Reporting of baseline data as done here is needed to ensure that data are available for marine birds over time and space scales in which we see changes in historical debris patterns in marine environments (i.e. decades) and among oceanographic regions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. A Brief History of Meteoroid and Orbital Debris Shielding Technology for US Manned Spacecraft

    Science.gov (United States)

    Bjorkman, Michael D.; Hyde, James L.

    2008-01-01

    Meteoroid and orbital debris shielding has played an important role from the beginning of manned spaceflight. During the early 60 s, meteoroid protection drove requirements for new meteor and micrometeoroid impact science. Meteoroid protection also stimulated advances in the technology of hypervelocity impact launchers and impact damage assessment methodologies. The first phase of meteoroid shielding assessments closed in the early 70 s with the end of the Apollo program. The second phase of meteoroid protection technology began in the early 80 s when it was determined that there is a manmade Earth orbital debris belt that poses a significant risk to LEO manned spacecraft. The severity of the Earth orbital debris environment has dictated changes in Space Shuttle and ISS operations as well as driven advances in shielding technology and assessment methodologies. A timeline of shielding technology and assessment methodology advances is presented along with a summary of risk assessment results.

  18. The Near-Earth Orbital Debris Problem and the Challenges for Environment Remediation

    Science.gov (United States)

    Liou, Jer-Chyi

    2012-01-01

    The near-Earth space environment has been gradually polluted with orbital debris (OD) since the beginning of space activities 55 years ago. Although this problem has been known to the research community for decades, the public was, in general, unaware of the issue until the anti-satellite test conducted by China in 2007 and the collision between Cosmos 2251 and the operational Iridium 33 in 2009. The latter also underlined the potential of an ongoing collision cascade effect (the "Kessler Syndrome") in the low Earth orbit (LEO, the region below 2000 km altitude). Recent modeling results have indicated that mitigation measures commonly adopted by the international space community will be insufficient to stabilize the LEO debris population. To better limit the OD population increase, more aggressive actions must be considered. There are three options for OD environment remediation-removal of large/massive intact objects to address the root cause of the OD population growth problem, removal of 5-mm-to-1 cm debris to mitigate the main mission-ending threats for the majority of operational spacecraft, and prevention of major debris-generating collisions as a temporary means to slow down the OD population increase. The technology, engineering, and cost challenges to carry out any of these three options are monumental. It will require innovative ideas, game-changing technologies, and major collaborations at the international level to address the OD problem and preserve the near-Earth environment for future generations.

  19. Debris disc constraints on planetesimal formation

    Science.gov (United States)

    Krivov, Alexander V.; Ide, Aljoscha; Löhne, Torsten; Johansen, Anders; Blum, Jürgen

    2018-02-01

    Two basic routes for planetesimal formation have been proposed over the last decades. One is a classical `slow-growth' scenario. Another one is particle concentration models, in which small pebbles are concentrated locally and then collapse gravitationally to form planetesimals. Both types of models make certain predictions for the size spectrum and internal structure of newly born planetesimals. We use these predictions as input to simulate collisional evolution of debris discs left after the gas dispersal. The debris disc emission as a function of a system's age computed in these simulations is compared with several Spitzer and Herschel debris disc surveys around A-type stars. We confirm that the observed brightness evolution for the majority of discs can be reproduced by classical models. Further, we find that it is equally consistent with the size distribution of planetesimals predicted by particle concentration models - provided the objects are loosely bound `pebble piles' as these models also predict. Regardless of the assumed planetesimal formation mechanism, explaining the brightest debris discs in the samples uncovers a `disc mass problem'. To reproduce such discs by collisional simulations, a total mass of planetesimals of up to ˜1000 Earth masses is required, which exceeds the total mass of solids available in the protoplanetary progenitors of debris discs. This may indicate that stirring was delayed in some of the bright discs, that giant impacts occurred recently in some of them, that some systems may be younger than previously thought or that non-collisional processes contribute significantly to the dust production.

  20. Cetaceans and Marine Debris: The Great Unknown

    Directory of Open Access Journals (Sweden)

    Mark Peter Simmonds

    2012-01-01

    Full Text Available Plastics and other marine debris have been found in the gastrointestinal tracts of cetaceans, including instances where large quantities of material have been found that are likely to cause impairment to digestive processes and other examples, where other morbidity and even death have resulted. In some instances, debris may have been ingested as a result of the stranding process and, in others, it may have been ingested when feeding. Those species that are suction or “ram” feeders may be most at risk. There is also evidence of entanglement of cetaceans in marine debris. However, it is usually difficult to distinguish entanglement in active fishing gear from that in lost or discarded gear. The overall significance of the threat from ingested plastics and other debris remains unclear for any population or species of cetaceans, although there are concerns for some taxa, including at the population level, and marine debris in the oceans continues to grow. Further research including the compilation of unpublished material and the investigation of important habitat areas is strongly recommended.

  1. The 2002 Starting Artificial Intelligence Researchers Symposium

    OpenAIRE

    Vidal, Thierry

    2003-01-01

    During the 2002 European Conference on Artificial Intelligence (ECAI-02) was introduced the Starting Artificial Intelligence Researchers Symposium STAIRS), the first-ever international symposium specifically aimed at Ph.D. students in AI. The outcome was a thorough, high-quality, and successful event, with all the features one usually finds in the best international conferences: large international committees, comprehensive coverage, published proceedings, renowned speakers and panelists, sub...

  2. Welcome and introduction to symposium - Day 2

    OpenAIRE

    humanities, Symposium on Information and technology in the arts and; McLaughlin, Jeremy Lee; Matusiak, Krystyna

    2015-01-01

    Welcome and introduction slides used for presentation at Day 2 of the Virtual Symposium on Information and Technology in the Arts and Humanities, held April 22 and 23, 2015. The Symposium was co-sponsored by the ASIS&T (Association for Information Science and Technology) Special Interest Group for Arts and Humanities (SIG AH) and the Special Interest Group for Visualization, Images, and Sound (SIG VIS).

  3. XXXIX Symposium on Nuclear Physics

    International Nuclear Information System (INIS)

    Acosta, Luis; Bijker, Roelof

    2016-01-01

    In the present volume of Journal of Physics: Conference Series we publish the proceedings of the “XXXIX Symposium on Nuclear Physics”, that was held from January 5-8, 2016 at the Hacienda Cocoyoc, Morelos, Mexico. The proceedings consist of 20 contributions that were presented as plenary talks at the meeting. The abstracts of all contributions, invited talks and posters, were published in the Conference Handbook. The Symposium on Nuclear Physics has a long and distinguished history. From the beginning it was intended to be a relatively small meeting designed to bring together some of the leading nuclear scientists in the field. Its most distinctive feature is to provide a forum for specialists in different areas of nuclear physics, both theorists and experimentalists, students, postdocs and senior scientists, in a relaxed and informal environment providing them with a unique opportunity to exchange ideas. After the first meeting in Oaxtepec in 1978, the Symposium was organized every year without interruption which makes the present one the 39th in a row. The scientific program consisted of 29 invited talks and a poster session on a wide variety of hot topics in contemporary nuclear physics, ranging from the traditional fields of nuclear structure and nuclear reactions to radioactive beams, nuclear astrophysics, hadronic physics, fundamental symmetries and relativistic heavy ions, as well as progress reports of large international projects like the HAWC Observatory in Puebla, Mexico, and the ATLAS and ALICE Collaborations of the LHC accelerator at CERN, Switzerland. In addition, there were several contributions highlighting interesting new results from foreign laboratories like Notre Dame, RIKEN, Jefferson Lab, Oak Ridge, INFN-Legnaro and INFN-LNS, as well as Mexican laboratories at ININ, LEMA and the Carlos Graef Laboratory at IF-UNAM. On the theoretical side there were talks on recent developments in nuclear structure, weakly bound nuclei, cluster models

  4. Proceedings of the TOUGH Symposium 2009

    Energy Technology Data Exchange (ETDEWEB)

    Moridis, George J.; Doughty, Christine; Finsterle, Stefan; Sonnenthal, Eric

    2009-10-01

    Welcome to the TOUGH Symposium 2009. Within this volume are the Symposium Program for eighty-nine papers to be presented in both oral and poster formats. The full papers are available as pdfs linked from the Symposium Program posted on the TOUGH Symposium 2009 website http://esd.lbl.gov/newsandevents/events/toughsymposium09/program.html Additional updated information including any changes to the Program will also be available at the website. The papers cover a wide range of application areas and reflect the continuing trend toward increased sophistication of the TOUGH codes. A CD containing the proceedings papers will be published immediately following the Symposium and sent to all participants. As in the prior Symposium, selected papers will be invited for submission to a number of journals for inclusion in Special Issues focused on applications and developments of the TOUGH codes. These journals include, Transport in Porous Media, Geothermics, Energy Conversion and Management, Journal of Nuclear Science and Technology, and the Vadose Zone Journal.

  5. Sixth BHD Symposium and First International Upstate Kidney Cancer Symposium: latest scientific and clinical discoveries

    OpenAIRE

    Bratslavsky, Gennady; Woodford, Mark R.; Daneshvar, Michael; Mollapour, Mehdi

    2016-01-01

    The Sixth BHD Symposium and First International Upstate Kidney Cancer Symposium concluded in September 2015, in Syracuse, NY, USA. The program highlighted recent findings in a variety of areas, including drug development, therapeutics and surgical management of patients with BHD and multi-focal renal tumors, as well as multidisciplinary approaches for patients with localized, locally advanced and metastatic renal cell carcinoma.

  6. Sixth BHD Symposium and First International Upstate Kidney Cancer Symposium: latest scientific and clinical discoveries.

    Science.gov (United States)

    Bratslavsky, Gennady; Woodford, Mark R; Daneshvar, Michael; Mollapour, Mehdi

    2016-03-29

    The Sixth BHD Symposium and First International Upstate Kidney Cancer Symposium concluded in September 2015, in Syracuse, NY, USA. The program highlighted recent findings in a variety of areas, including drug development, therapeutics and surgical management of patients with BHD and multi-focal renal tumors, as well as multidisciplinary approaches for patients with localized, locally advanced and metastatic renal cell carcinoma.

  7. Introduction to the Paper Symposium

    Science.gov (United States)

    Carpenter, D. K.

    1996-05-01

    Most students of physical chemistry, as well as their teachers, regard equilibrium chemical thermodynamics as an impressive, useful, and stable subject that was "finished" long ago. As part of their education, students in physical chemistry have been taught the importance and the usefulness of the Gibbs function (formerly called the Gibbs free energy function). The antiquity of the subject and the presumed mastery of its basics by physical chemistry teachers are taken for granted as given parts of the educational and scientific scene in chemical education. It comes as a surprise to occasionally discover that even those who teach this venerable subject sometimes disagree, not merely in matters of style or organization of the subject, or in matters of mathematical elegance, but in matters of real substance. The following four papers are examples of this. My role here is simply to introduce this set of papers and to provide some orientation regarding their contents. The authors have been in private communication with each other for a period of over four years about the use and the proper definition of the Gibbs function. The lengthy period of correspondence has not resulted in any significant agreement. The Editor of this Journal was unable to settle the resulting controversy by normal review procedures. In an attempt to break the deadlock he asked me, as an impartial outsider to the situation, for assistance in deciding an appropriate literary form in which the authors could present their own points of view as well as comments on the views of the other authors. The original hope was that agreement could eventually be reached on disputed points by the give and take of the interchange of further correspondence, and that the outcome would be published in the form of a "paper symposium" on the subject, with me as the "chairman" of the symposium. It must be said at the outset that the prolonged correspondence has not produced much agreement among the authors. This is

  8. Symposium on accelerator mass spectrometry

    International Nuclear Information System (INIS)

    1981-01-01

    The area of accelerator mass spectrometry has expanded considerably over the past few years and established itself as an independent and interdisciplinary research field. Three years have passed since the first meeting was held at Rochester. A Symposium on Accelerator Mass Spectrometry was held at Argonne on May 11-13, 1981. In attendance were 96 scientists of whom 26 were from outside the United States. The present proceedings document the program and excitement of the field. Papers are arranged according to the original program. A few papers not presented at the meeting have been added to complete the information on the status of accelerator mass spectrometry. Individual papers were prepared separately for the data base

  9. Symposium on accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-01-01

    The area of accelerator mass spectrometry has expanded considerably over the past few years and established itself as an independent and interdisciplinary research field. Three years have passed since the first meeting was held at Rochester. A Symposium on Accelerator Mass Spectrometry was held at Argonne on May 11-13, 1981. In attendance were 96 scientists of whom 26 were from outside the United States. The present proceedings document the program and excitement of the field. Papers are arranged according to the original program. A few papers not presented at the meeting have been added to complete the information on the status of accelerator mass spectrometry. Individual papers were prepared separately for the data base.

  10. World Population Day special symposium.

    Science.gov (United States)

    1998-08-01

    This article describes Japan's celebration of World Population Day, and provides excerpts from speeches at the symposium held on July 8, 1998. The symposium, in Tokyo, was attended by about 300 people. The Chairman of JOICFP gave the opening address. The executive director of UNFPA congratulated Japan for its efforts in the field of population awareness and noted Japan's self-sufficiency despite its importation of 40% of its food and most of its raw materials. A keynote address was delivered by the president of CPE and the former UN Secretary General, who stressed income inequities in the 66% of developing countries within the 185 UN member states. The UN has been promoting sustainable development, but is facing the issue of limited arable land and population growth. The Tutsi and Hutus are fighting due to population based issues. The emphasis should be on women's reproductive rights and protection of women's human rights. 1998 is the 50th year of human rights; progress has been made. The UNFPA Goodwill Ambassador spoke about the disparity between the rich and poor in the Philippines. A small donation reaps incredible progress. Manila has high levels of adolescent childbearing. Men appear to be unaware of the disadvantages of childbearing too early. Rural areas are dominated by strict Roman Catholic beliefs. Manila has commercial sex workers who provide services to Japanese men. The 1998 Kato Award was given to women who raised awareness about coercion in the sex trade and female genital mutilation. The economic situation in Japan creates even greater need to promote family planning and reproductive health.

  11. International waste-management symposium

    International Nuclear Information System (INIS)

    Shoup, R.L.

    1977-01-01

    An International Symposium on the Management of Wastes from the LWR Fuel Cycle was held in Denver, Colo., on July 11 to 16, 1976. The symposium covered a broad range of topics, from policy issues to technology. Presentations were made by national and international speakers involved in all aspects of waste management, government and agency officials; laboratory managers, directors, and researchers; and industrial representatives. Many speakers advocated pragmatic action on programs for the management of commercial nuclear wastes to complete the light-water reactor (LWR) fuel cycle. The industrialized nations' demand for increasing supplies of energy and their increasing dependence on nuclear energy to fulfill this demand will necessitate the development of an acceptable solution to the disposal of nuclear wastes within the next decade for some industrial nations. Waste-disposal technology should be implemented on a commercial scale, but the commercialization must be accompanied by the decision to use the technology. An important issue in the use of nuclear energy is the question of sharing the technology with the less industrialized nations and with nations that may not have suitable means to dispose of nuclear wastes. The establishment of international and multinational cooperation will be an important key in realizing this objective. Pressing issues that international organizations or task groups will have to address are ocean disposal, plutonium recycling and safeguards, and disposal criteria. The importance of achieving a viable waste-management program is made evident by the increased funding and attention that the back end of the fuel cycle is now receiving

  12. Flow characteristics of counter-current flow in debris bed

    International Nuclear Information System (INIS)

    Abe, Yutaka; Adachi, Hiromichi

    2004-01-01

    In the course of a severe accident, a damaged core would form a debris bed consisting of once-molten and fragmented fuel elements. It is necessary to evaluate the dryout heat flux for the judgment of the coolability of the debris bed during the severe accident. The dryout phenomena in the debris bed is dominated by the counter-current flow limitation (CCFL) in the debris bed. In this study, air-water counter-current flow behavior in the debris bed is experimentally investigated with glass particles simulating the debris beds. In this experiment, falling water flow rate and axial pressure distributions were experimentally measured. As the results, it is clarified that falling water flow rate becomes larger with the debris bed height and the pressure gradient in the upper region of the debris bed is different from that in the lower region of the debris bed. These results indicate that the dominant region for CCFL in the debris bed is identified near the top of the debris bed. Analytical results with annular flow model indicates that interfacial shear stress in the upper region of the debris bed is larger than that in the lower region of the debris bed. (author)

  13. Apparatus for controlling molten core debris

    International Nuclear Information System (INIS)

    Golden, M.P.; Tilbrook, R.W.; Heylmun, N.F.

    1972-01-01

    Disclosed is an apparatus for containing, cooling, diluting, dispersing and maintaining subcritical the molten core debris assumed to melt through the bottom of a nuclear reactor pressure vessel in the unlikely event of a core meltdown. The apparatus is basically a sacrificial bed system which includes an inverted conical funnel, a core debris receptacle including a spherical dome, a spherically layered bed of primarily magnesia bricks, a cooling system of zig-zag piping in graphite blocks about and below the bed and a cylindrical liner surrounding the graphite blocks including a steel shell surrounded by firebrick. Tantalum absorber rods are used in the receptacle and bed. 9 claims, 22 figures

  14. Electrometallurgical treatment of TMI-2 fuel debris

    International Nuclear Information System (INIS)

    Karell, E.J.; Gourishankar, K.V.; Johnson, G.K.

    1997-01-01

    Argonne National Laboratory (ANL) has developed an electrometallurgical treatment process suitable for conditioning DOE oxide spent fuel for long-term storage or disposal. The process consists of an initial oxide reduction step that converts the actinide oxides to a metallic form, followed by an electrochemical separation of uranium from the other fuel constituents. The final product of the process is a uniform set of stable waste forms suitable for long-term storage or disposal. The suitability of the process for treating core debris from the Three Mile Island-2 (TMI-2) reactor is being evaluated. This paper reviews the results of preliminary experimental work performed using simulated TMI-2 fuel debris

  15. Introduction and Overview of the Symposium Anil Kumar (Indian ...

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Introduction and Overview of the Symposium Anil Kumar (Indian Institute of Science, Bangalore). Symposium on Quantum Computing and Quantum Information. Notes:

  16. Space Surveillance Network and Analysis Model (SSNAM) Performance Improvements

    National Research Council Canada - National Science Library

    Butkus, Albert; Roe, Kevin; Mitchell, Barbara L; Payne, Timothy

    2007-01-01

    ... capacity by sensor, models for sensors yet to be created, user defined weather conditions, National Aeronautical and Space Administration catalog growth model including space debris, and solar flux just to name a few...

  17. Linking effects of anthropogenic debris to ecological impacts

    NARCIS (Netherlands)

    Browne, M.A.; Underwood, A.J.; Chapman, M.G.; Williams, R.; Thompson, R.C.; Franeker, van J.A.

    2015-01-01

    Accelerated contamination of habitats with debris has caused increased effort to determine ecological impacts. Strikingly, most work on organisms focuses on sublethal responses to plastic debris. This is controversial because (i) researchers have ignored medical insights about the mechanisms that

  18. Close Approach Prediction Analysis of the Earth Science Constellation with the Fengyun-1C Debris

    Science.gov (United States)

    Duncan, Matthew; Rand, David K.

    2008-01-01

    Routine satellite operations for the Earth Science Constellation (ESC) include collision risk assessment between members of the constellation and other orbiting space objects. Each day, close approach predictions are generated by a U.S. Department of Defense Joint Space Operations Center Orbital Safety Analyst using the high accuracy Space Object Catalog maintained by the Air Force's 1" Space Control Squadron. Prediction results and other ancillary data such as state vector information are sent to NASAJGoddard Space Flight Center's (GSFC's) Collision Risk Assessment analysis team for review. Collision analysis is performed and the GSFC team works with the ESC member missions to develop risk reduction strategies as necessary. This paper presents various close approach statistics for the ESC. The ESC missions have been affected by debris from the recent anti-satellite test which destroyed the Chinese Fengyun- 1 C satellite. The paper also presents the percentage of close approach events induced by the Fengyun-1C debris, and presents analysis results which predict the future effects on the ESC caused by this event. Specifically, the Fengyun-1C debris is propagated for twenty years using high-performance computing technology and close approach predictions are generated for the ESC. The percent increase in the total number of conjunction events is considered to be an estimate of the collision risk due to the Fengyun-1C break- UP.

  19. Interstellar Explorer Observations of the Solar System's Debris Disks

    Science.gov (United States)

    Lisse, C. M.; McNutt, R. L., Jr.; Brandt, P. C.

    2017-12-01

    Planetesimal belts and debris disks full of dust are known as the "signposts of planet formation" in exosystems. The overall brightness of a disk provides information on the amount of sourcing planetesimal material, while asymmetries in the shape of the disk can be used to search for perturbing planets. The solar system is known to house two such belts, the Asteroid belt and the Kuiper Belt; and at least one debris cloud, the Zodiacal Cloud, sourced by planetisimal collisions and Kuiper Belt comet evaporative sublimation. However these are poorly understood in toto because we live inside of them. E.g., while we know of the two planetesimal belt systems, it is not clear how much, if any, dust is produced from the Kuiper belt since the near-Sun comet contributions dominate near-Earth space. Understanding how much dust is produced in the Kuiper belt would give us a much better idea of the total number of bodies in the belt, especially the smallest ones, and their dynamical collisional state. Even for the close in Zodiacal cloud, questions remain concerning its overall shape and orientation with respect to the ecliptic and invariable planes of the solar system - they aren't explainable from the perturbations caused by the known planets alone. In this paper we explore the possibilities of using an Interstellar Explorer telescope placed at 200 AU from the sun to observe the brightness, shape, and extent of the solar system's debris disk(s). We should be able to measure the entire extent of the inner, near-earth zodiacal cloud; whether it connects smoothly into an outer cloud, or if there is a second outer cloud sourced by the Kuiper belt and isolated by the outer planets, as predicted by Stark & Kuchner (2009, 2010) and Poppe et al. (2012, 2016; Figure 1). VISNIR imagery will inform about the dust cloud's density, while MIR cameras will provide thermal imaging photometry related to the cloud's dust particle size and composition. Observing at high phase angle by looking

  20. Assessment of active methods for removal of LEO debris

    Science.gov (United States)

    Hakima, Houman; Emami, M. Reza

    2018-03-01

    This paper investigates the applicability of five active methods for removal of large low Earth orbit debris. The removal methods, namely net, laser, electrodynamic tether, ion beam shepherd, and robotic arm, are selected based on a set of high-level space mission constraints. Mission level criteria are then utilized to assess the performance of each redirection method in light of the results obtained from a Monte Carlo simulation. The simulation provides an insight into the removal time, performance robustness, and propellant mass criteria for the targeted debris range. The remaining attributes are quantified based on the models provided in the literature, which take into account several important parameters pertaining to each removal method. The means of assigning attributes to each assessment criterion is discussed in detail. A systematic comparison is performed using two different assessment schemes: Analytical Hierarchy Process and utility-based approach. A third assessment technique, namely the potential-loss analysis, is utilized to highlight the effect of risks in each removal methods.

  1. Monitoring the abundance of plastic debris in the marine environment

    OpenAIRE

    Ryan, Peter G.; Moore, Charles J.; van Franeker, Jan A.; Moloney, Coleen L.

    2009-01-01

    Plastic debris has significant environmental and economic impacts in marine systems. Monitoring is crucial to assess the efficacy of measures implemented to reduce the abundance of plastic debris, but it is complicated by large spatial and temporal heterogeneity in the amounts of plastic debris and by our limited understanding of the pathways followed by plastic debris and its long-term fate. To date, most monitoring has focused on beach surveys of stranded plastics and other litter. Infreque...

  2. Property measurements and inner state estimation of simulated fuel debris

    Energy Technology Data Exchange (ETDEWEB)

    Hirooka, S.; Kato, M.; Morimoto, K.; Washiya, T. [Japan Atomic Energy Agency, Ibaraki (Japan)

    2014-07-01

    Fuel debris properties and inner state such as temperature profile were evaluated by using analysis of simulated fuel debris manufactured from UO{sub 2} and oxidized zircaloy. The center of the fuel debris was expected to be molten state soon after the melt down accident of LWRs because power density was very high. On the other hand, the surface of the fuel debris was cooled in the water. This large temperature gradient may cause inner stress and consequent cracks were expected. (author)

  3. PREFACE: International Symposium on `Vacuum Science and Technology' (IVS 2007)

    Science.gov (United States)

    Mittal, K. C.; Gupta, S. K.

    2008-03-01

    The Indian Vacuum Society (established in 1970) has organized a symposium every alternate year on various aspects of vacuum science and technology. There has been considerable participation from R & D establishments, universities and Indian industry in this event. In view of the current global scenario and emerging trends in vacuum technology, this year, the executive committee of IVS felt it appropriate to organize an international symposium at Tata Institute of Fundamental Research, Colaba, Mumbai 400 005 from 29-30 November 2007. This symposium provided a forum for exchange of information among vacuum scientists, technologists and industrialists on recent advances made in the areas of large vacuum systems, vacuum production, its measurement and applications in industry, and material processing in vacuum. Vacuum science and technology has made vital contributions in high tech areas like space, high energy particle accelerators, large plasma systems, electronics, thin films, melting and refining of metals, extraction and processing of advanced materials etc. The main areas covered in the symposium were the production and measurement of vacuums, leak detection, large vacuum systems, vacuum metallurgy, vacuum materials and processing inclusive of applications of vacuum in industry. Large vacuum systems for high energy particle accelerators, plasma devices and light sources are of special significance for this symposium. Vacuum evaporation, hard coatings, thin films, joining techniques, sintering, melting and heat treatment, furnaces and thermo dynamics are also covered in this symposium. There were eighteen invited talks from the best experts in the respective fields and more than one hundred contributed papers. This fact itself indicates the interest that has been generated amongst the scientists, technologists and industrialists in this field. In view of the industrial significance of the vacuum technology, an exhibition of vacuum and vacuum processing related

  4. On the Solar System-Debris Disk Connecction

    OpenAIRE

    Moro-Martin, Amaya

    2007-01-01

    This paper emphasizes the connection between solar and extra-solar debris disks: how models and observations of the Solar System are helping us understand the debris disk phenomenon, and vice versa, how debris disks are helping us place our Solar System into context.

  5. Debris prevention system, radiation system, and lithograpic apparatus

    NARCIS (Netherlands)

    2009-01-01

    A debris prevention system is constructed and arranged to prevent debris that emanates from a radiation source from propagating with radiation from the radiation source into or within a lithographic apparatus. The debris prevention system includes an aperture that defines a maximum emission angle of

  6. Monitoring the abundance of plastic debris in the marine environment

    NARCIS (Netherlands)

    Ryan, P.G.; Moore, C.J. C.J.; Franeker, van J.A.; Moloney, C.L.

    2009-01-01

    Plastic debris has significant environmental and economic impacts in marine systems. Monitoring is crucial to assess the efficacy of measures implemented to reduce the abundance of plastic debris, but it is complicated by large spatial and temporal heterogeneity in the amounts of plastic debris and

  7. Theft of Debris from the Space Shuttle Columbia: Criminal Penalties

    National Research Council Canada - National Science Library

    Murnane, Andrew W; Eig, Larry

    2003-01-01

    .... This report briefly describes possible criminal penalties for conversion of government property, and does not address issues related to the personal property of the Columbia's crew. This report will be updated as warranted.

  8. Conditioning of metallic Magnox fuel element debris

    International Nuclear Information System (INIS)

    Kaye, C.J.

    1983-01-01

    The conditioning of metallic Magnox debris poses particular problems arising from its chemical reactivity and from the presence in discrete amounts of highly radioactive components. The treatment of this waste is currently being studied by the Central Electricity Generating Board. Following retrieval from store it is envisaged that the debris will be dried and comminuted to facilitate the removal for further storage of the highly active components from the bulk debris. A satisfactory means of sorting the debris appears to be by magnetic induction. The relatively low activity but potentially reactive Magnox will then be directly encapsulated prior to disposal off-site. Currently the only disposal route open for this waste is to the deep ocean. Matrices for encapsulating Magnox have been developed and others are under investigation. The desirable features of such matrices include low chemical reactivity and impermeability to water. The methods used to characterize the resultant waste forms and the results obtained are presented. Thermosetting polymers produce suitable waste forms for sea disposal, exhibiting high mechanical strength and resistance to leaching, and possessing very low chemical reactivity with respect to the Magnox waste. Low viscosity matrices are advantageous from the point of view of the process plant engineering as they enable the comminuted waste to be directly encapsulated. (author)

  9. Europium-155 in Debris from Nuclear Weapons

    DEFF Research Database (Denmark)

    Aarkrog, Asker; Lippert, Jørgen Emil

    1967-01-01

    The lithium-drifted germanium detector enables determination of europium-155 on a routine basis in environmental samples contaminated with debris from nuclear weapons. From measurements of europium-155, cesium-144, and strontium-90 in air filters collected between 1961 and 1966, the yield...

  10. Numerical modeling of the debris flows runout

    Directory of Open Access Journals (Sweden)

    Federico Francesco

    2017-01-01

    Full Text Available Rapid debris flows are identified among the most dangerous of all landslides. Due to their destructive potential, the runout length has to be predicted to define the hazardous areas and design safeguarding measures. To this purpose, a continuum model to predict the debris flows mobility is developed. It is based on the well known depth-integrated avalanche model proposed by Savage and Hutter (S&H model to simulate the dry granular materials flows. Conservation of mass and momentum equations, describing the evolving geometry and the depth averaged velocity distribution, are re-written taking into account the effects of the interstitial pressures and the possible variation of mass along the motion due to erosion/deposition processes. Furthermore, the mechanical behaviour of the debris flow is described by a recently developed rheological law, which allows to take into account the dissipative effects of the grain inelastic collisions and friction, simultaneously acting within a ‘shear layer’, typically at the base of the debris flows. The governing PDEs are solved by applying the finite difference method. The analysis of a documented case is finally carried out.

  11. Plastic Debris Is a Human Health Issue

    NARCIS (Netherlands)

    Vethaak, A.D.; Leslie, H.A.

    2016-01-01

    The global threat of highly persistent plastic waste accumulating and fragmenting in the world’s oceans, inland waters and terrestrial environments is becoming increasingly evident.1−3 Humans are being exposed to both plastic particles and chemical additives being released from the plastic debris of

  12. Optical Photometric Observations of GEO Debris

    Science.gov (United States)

    Seitzer, Patrick; Rodriquez-Cowardin, Heather M.; Barker, Edwin S.; Abercromby, Kira J.; Kelecy, Thomas M.; Horstman, Matt

    2010-01-01

    We report on a continuing program of optical photometric measurements of faint orbital debris at geosynchronous Earth orbit (GEO). These observations can be compared with laboratory studies of actual spacecraft materials in an effort to determine what the faint debris at GEO may be. We have optical observations from Cerro Tololo Inter-American Observatory (CTIO) in Chile of two samples of debris: 1. GEO objects discovered in a survey with the University of Michigan's 0.6-m aperture Curtis-Schmidt telescope MODEST (for Michigan Orbital DEbris Survey Telescope), and then followed up in real-time with the CTIO/SMARTS 0.9-m for orbits and photometry. Our goal is to determine 6 parameter orbits and measure colors for all objects fainter than R = 15 t11 magnitude that are discovered in the MODEST survey. 2. A smaller sample of high area to mass ratio (AMR) objects discovered independently, and acquired using predictions from orbits derived from independent tracking data collected days prior to the observations. Our optical observations in standard astronomical BVRI filters are done with either telescope, and with the telescope tracking the debris object at the object's angular rate. Observations in different filters are obtained sequentially. We have obtained 71 calibrated sequences of R-B-V-I-R magnitudes. A total of 66 of these sequences have 3 or more good measurements in all filters (not contaminated by star streaks or in Earth's shadow). Most of these sequences show brightness variations, but a small subset has observed brightness variations consistent with that expected from observational errors alone. The majority of these stable objects are redder than a solar color in both B-R and R-I. There is no dependence on color with brightness. For a smaller sample of objects we have observed with synchronized CCD cameras on the two telescopes. The CTIO 0.9-m observes in B, and MODEST in R. The CCD cameras are electronically linked together so that the start time and

  13. Photometric Studies of GEO Orbital Debris

    Science.gov (United States)

    Seitzer, Patrick; Rodriquez-Cowardin, Heather M.; Barker, Ed; Abercromby, Kira J.; Foreman, Gary; Horstman, Matt

    2009-01-01

    The photometric signature of a debris object can be useful in determining what the physical characteristics of a piece of debris are. We report on optical observations in multiple filters of debris at geosynchronous Earth orbit (GEO). Our sample is taken from GEO objects discovered in a survey with the University of Michigan's 0.6-m aperture Schmidt telescope MODEST (for Michigan Orbital DEbris Survey Telescope), and then followed up in real-time with the Cerro Tololo Inter- American Observatory (CTIO) 0.9-m for orbits and photometry. Our goal is to determine 6 parameter orbits and measure colors for all objects fainter than R=15th magnitude that are discovered in the MODEST survey. At this magnitude the distribution of observed angular rates changes significantly from that of brighter objects. There are two objectives: 1. Estimate the orbital distribution of objects selected on the basis of two observational criteria: brightness (magnitude) and angular rates. 2. Obtain magnitudes and colors in standard astronomical filters (BVRI) for comparison with reflectance spectra of likely spacecraft materials. What is the faint debris likely to be? More than 90 calibrated sequences of R-B-V-I-R magnitudes for a sample of 50 objects have been obtained with the CTIO 0.9-m. For objects that do not show large brightness variations, the colors are largely redder than solar in both B-R and R-I. The width of the color distribution may be intrinsic to the nature of the surfaces, but also could be that we are seeing irregularly shaped objects and measuring the colors at different times with just one telescope. For a smaller sample of objects we have observed with synchronized CCD cameras on the two telescopes. The CTIO 0.9-m observes in B, and MODEST in R. The CCD cameras are electronically linked together so that the start time and duration of observations are the same to better than 50 milliseconds. Thus the B-R color is a true measure of the surface of the debris piece facing the

  14. 170th Symposium of the International Astronomical Union

    CERN Document Server

    Radford, Simon; Jewell, Philip; Mangum, Jeffrey; Bally, John

    1997-01-01

    Interstellar carbon monoxide (CO) was first detected in 1970 with the 36 foot diameter telescope of the National Radio Astronomy Observatory! on Kitt Peak in Southern Arizona. R. W. Wilson, K. B. Jefferts, and A. A. Penzias of Bell Labs reported, "We have found intense 2.6 mm line radiation 2 from nine Galactic sources which we attribute to carbon monoxide." Soon afterward, several other basic molecules were also observed in space. IAU Symposium 170, CO: Twenty Five Years of Millimeter Wave Spectroscopy, was organized to commemorate those discoveries. The Symposium reviewed the accomplishments of a quarter century of research on interstellar molec­ ular gas, surveyed the current state of millimeter-wave spectroscopy, and gave a glimpse of what the next 25 years might hold. Studies of interstellar CO have revolutionized our understanding of the phases and dynamics of the interstellar medium, the initial and final stages of stellar evolution, the chemistry of dense and diffuse interstellar matter and of the so...

  15. 2. Symposium environmental geotechnics. Papers; 2. Symposium Umweltgeotechnik. Konferenzband

    Energy Technology Data Exchange (ETDEWEB)

    Klapperich, H. [TU Bergakademie Freiberg (Germany). Inst. fuer Geotechnik]|[Kompetenz-Zentrum fuer interdisziplinaeres Flaechenrecycling CIF e.V., Freiberg (ED); Katzenbach, R. [Deutsche Gesellschaft fuer Geotechnike e.V., Essen (Germany); Witt, K.J. [Bauhaus-Universitaet Weimar (Germany); Griessl, D. (eds.) [Verein Freiberger Geotechniker e.V. (Germany)

    2005-07-01

    The 2nd symposium of the chapter section 'Environmental Geotechnics' of DGGT follows the event in Weimar 2003 and focuses on the central topics of Landfill - Contaminated Sites - Brownfields. The stream 'Waste management - Waste Site technology' discusses legal requirements and technical alternatives, especially in view of many upcoming closures of landfill sites and associated surface sealing, as well as technical reports of case studies and developments. The contribution 'Ultimate storage of radioactive waste' illustrates the wider dimensions to geotechnical questions. Between the streams of 'Remediation Techniques' and 'Land Recycling/Land Management' a panel discussion 'From Brownfield Remediation to Land Management' is taking place. The aim is to discuss the way forward and the need to take up the opportunity for future town planning as well as the design of conversion sites and expansive former mining areas. Representatives of authorities involved and project participants have submitted their statements in advance to the following question: 1.) status of remediation - research and practice 2.) what practical significance is attributed to different remediation techniques for the remediation of brownfields? 3.) modern town planning/redevelopment of former mining areas - spatial planning - real estate economy - financing models for redeveloping land - which parameters/instruments work? (orig.)

  16. THE SPITZER INFRARED SPECTROGRAPH DEBRIS DISK CATALOG. I. CONTINUUM ANALYSIS OF UNRESOLVED TARGETS

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Christine H. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Mittal, Tushar [Department of Earth and Planetary Science, University of California Berkeley, Berkeley, CA 94720-4767 (United States); Kuchner, Marc [NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics Laboratory, Code 667, Greenbelt, MD 20771 (United States); Forrest, William J.; Watson, Dan M. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); Lisse, Carey M. [Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States); Manoj, P. [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005 (India); Sargent, Benjamin A., E-mail: cchen@stsci.edu [Center for Imaging Science and Laboratory for Multiwavelength Astrophysics, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623 (United States)

    2014-04-01

    During the Spitzer Space Telescope cryogenic mission, Guaranteed Time Observers, Legacy Teams, and General Observers obtained Infrared Spectrograph (IRS) observations of hundreds of debris disk candidates. We calibrated the spectra of 571 candidates, including 64 new IRAS and Multiband Imaging Photometer for Spitzer (MIPS) debris disks candidates, modeled their stellar photospheres, and produced a catalog of excess spectra for unresolved debris disks. For 499 targets with IRS excess but without strong spectral features (and a subset of 420 targets with additional MIPS 70 μm observations), we modeled the IRS (and MIPS data) assuming that the dust thermal emission was well-described using either a one- or two-temperature blackbody model. We calculated the probability for each model and computed the average probability to select among models. We found that the spectral energy distributions for the majority of objects (∼66%) were better described using a two-temperature model with warm (T {sub gr} ∼ 100-500 K) and cold (T {sub gr} ∼ 50-150 K) dust populations analogous to zodiacal and Kuiper Belt dust, suggesting that planetary systems are common in debris disks and zodiacal dust is common around host stars with ages up to ∼1 Gyr. We found that younger stars generally have disks with larger fractional infrared luminosities and higher grain temperatures and that higher-mass stars have disks with higher grain temperatures. We show that the increasing distance of dust around debris disks is inconsistent with self-stirred disk models, expected if these systems possess planets at 30-150 AU. Finally, we illustrate how observations of debris disks may be used to constrain the radial dependence of material in the minimum mass solar nebula.

  17. Toward human organ printing: Charleston Bioprinting Symposium.

    Science.gov (United States)

    Mironov, Vladimir

    2006-01-01

    The First Annual Charleston Bioprinting Symposium was organized by the Bioprinting Research Center of the Medical University of South Carolina (MUSC) and convened July 21, 2006, in Charleston, South Carolina. In broad terms, bioprinting is the application of rapid prototyping technology to the biomedical field. More specifically, it is defined as the layer by layer deposition of biologically relevant material. The 2006 Symposium included four sessions: Computer-aided design and Bioprinting, Bioprinting Technologies; Hydrogel for Bioprinting and, finally, a special session devoted to ongoing research projects at the MUSC Bioprinting Research Center. The Symposium highlight was the presentation of the multidisciplinary Charleston Bioengineered Kidney Project. This symposium demonstrated that bioprinting or robotic biofabrication is one of the most exciting and fast-emerging branches in the tissue engineering field. Robotic biofabrication will eventually lead to industrial production of living human organs suitable for clinical transplantation. The symposium demonstrated that although there are still many technological challenges, organ printing is a rapidly evolving feasible technology.

  18. The 12th International Symposium on Spermatology

    Science.gov (United States)

    Aitken, R John; Cummins, Jim M; Nixon, Brett

    2015-01-01

    The 12th International Symposium of Spermatology continued the excellent tradition of this meeting since its inception in 1969 when the first Symposium was held in Italy under the Chairmanship of Professor Baccio Baccetti. This unique Symposium is held every 4 years and serves as a beacon for sperm cell biologists from all over the world, regardless of which species, animal or plant, they are working on. This willingness to embrace the fundamental biology of this distinctive cell type without species limitations is one of the hallmarks of this Symposium. For sperm biologists – it is our Olympics. The meeting in Newcastle, NSW brought together around 300 biologists from more than 22 different countries covering North and South America, Africa, Europe, Asia and Australia. Given the considerable distances and high cost involved in travelling to the East Coast of NSW, this was an outstanding outcome. The Symposium featured a series of 31 plenary lectures culminating in the prestigious Thaddeus Mann Memorial Lecture, which was delivered with typical grace and brilliance by Professor Masaru Okabe. PMID:25994646

  19. Proceedings of the symposium on networking

    International Nuclear Information System (INIS)

    Karita, Yukio; Abe, Fumio

    1989-06-01

    The first symposium on networking was held on February 6-7, 1989. Due to the increase of the needs of computer networks, several networks which connect among universities and laboratories are going to be constructed in Japan. However, the techniques in networking are not familiar to most people, and the information about these techniques is sometimes difficult to get, especially in multivendor connection. In such situation, an opportunity to hold a symposium on networking at the National Laboratory for High Energy Physics (KEK) was given. More than 200 people took part in this symposium, and the local area networks in institutions, the networks among institutions, the networks for high energy physics, the application of networks, the networks for academic research and so on are reported. The valuable discussion about networks was carried out, including the plans for near future. At the time of this symposium, the construction of the Gakujo-net and the Pacific network project of University of Hawaii were in progress, and many Japanese universities are going to construct their campus LANs, so the symposium seemed to be very timely. (K.I.)

  20. 7th International Fermi Symposium

    Science.gov (United States)

    2017-10-01

    especially encourage guest investigators worldwide to participate in this symposium to share results and to learn about upcoming opportunities. This meeting will focus on the new scientific investigations and results enabled by Fermi, the mission and instrument characteristics, future opportunities, coordinated observations and analysis techniques. In particular, we also encourage discussion of future prospects/science with Fermi in preparation for the upcoming NASA senior review. Details on the 7th International Fermi Symposium can be found here: https://events.mpe.mpg.de/Fermi2017

  1. NASA's New Orbital Debris Engineering Model, ORDEM2010

    Science.gov (United States)

    Krisko, Paula H.

    2010-01-01

    This paper describes the functionality and use of ORDEM2010, which replaces ORDEM2000, as the NASA Orbital Debris Program Office (ODPO) debris engineering model. Like its predecessor, ORDEM2010 serves the ODPO mission of providing spacecraft designers/operators and debris observers with a publicly available model to calculate orbital debris flux by current-state-of-knowledge methods. The key advance in ORDEM2010 is the input file structure of the yearly debris populations from 1995-2035 of sizes 10 micron - 1 m. These files include debris from low-Earth orbits (LEO) through geosynchronous orbits (GEO). Stable orbital elements (i.e., those that do not randomize on a sub-year timescale) are included in the files as are debris size, debris number, material density, random error and population error. Material density is implemented from ground-test data into the NASA breakup model and assigned to debris fragments accordingly. The random and population errors are due to machine error and uncertainties in debris sizes. These high-fidelity population files call for a much higher-level model analysis than what was possible with the populations of ORDEM2000. Population analysis in the ORDEM2010 model consists of mapping matrices that convert the debris population elements to debris fluxes. One output mode results in a spacecraft encompassing 3-D igloo of debris flux, compartmentalized by debris size, velocity, pitch, and yaw with respect to spacecraft ram direction. The second output mode provides debris flux through an Earth-based telescope/radar beam from LEO through GEO. This paper compares the new ORDEM2010 with ORDEM2000 in terms of processes and results with examples of specific orbits.

  2. Prediction of corium debris characteristics in lower plenum of a nordic BWR in different accident scenarios using MELCOR code - 15367

    International Nuclear Information System (INIS)

    Phung, V.A.; Galushin, S.; Raub, S.; Goronovski, A.; Villanueva, W.; Koeoep, K; Grishchenko, D.; Kudinov, P.

    2015-01-01

    Severe accident management strategy in Nordic boiling water reactors (BWRs) relies on ex-vessel core debris coolability. The mode of corium melt release from the vessel determines conditions for ex-vessel accident progression and threats to containment integrity, e.g., formation of a non-coolable debris bed and possibility of energetic steam explosion. In-vessel core degradation and relocation is an important stage which determines characteristics of corium debris in the vessel lower plenum, such as mass, composition, thermal properties, timing of relocation, and decay heat. These properties affect debris reheating and remelting, melt interactions with the vessel structures, and possibly vessel failure and melt ejection mode. Core degradation and relocation is contingent upon the accident scenario parameters such as recovery time and capacity of safety systems. The goal of this work is to obtain a better understanding of the impact of the accident scenarios and timing of the events on core relocation phenomena and resulting properties of the debris bed in the vessel lower plenum of Nordic BWRs. In this study, severe accidents in a Nordic BWR reference plant are initiated by a station black out event, which is the main contributor to core damage frequency of the reactor. The work focuses on identifying ranges of debris bed characteristics in the lower plenum as functions of the accident scenario with different recovery timing and capacity of safety systems. The severe accident analysis code MELCOR coupled with GA-IDPSA is used in this work. GA-IDPSA is a Genetic Algorithm-based Integrated Deterministic Probabilistic Safety Analysis tool, which has been developed to search uncertain input parameter space. The search is guided by different target functions. Scenario grouping and clustering approach is applied in order to estimate the ranges of debris characteristics and identify scenario regions of core relocation that can lead to significantly different debris bed

  3. Internet Based Simulations of Debris Dispersion of Shuttle Launch

    Science.gov (United States)

    Bardina, Jorge; Thirumalainambi, Rajkumar

    2004-01-01

    The debris dispersion model (which dispersion model?) is so heterogeneous and interrelated with various factors, 3D graphics combined with physical models are useful in understanding the complexity of launch and range operations. Modeling and simulation in this area mainly focuses on orbital dynamics and range safety concepts, including destruct limits, telemetry and tracking, and population risk. Particle explosion modeling is the process of simulating an explosion by breaking the rocket into many pieces. The particles are scattered throughout their motion using the laws of physics eventually coming to rest. The size of the foot print explains the type of explosion and distribution of the particles. The shuttle launch and range operations in this paper are discussed based on the operations of the Kennedy Space Center, Florida, USA. Java 3D graphics provides geometric and visual content with suitable modeling behaviors of Shuttle launches.

  4. Numerical simulation of the debris flow dynamics with an upwind scheme and specific friction treatment

    Science.gov (United States)

    Sánchez Burillo, Guillermo; Beguería, Santiago; Latorre, Borja; Burguete, Javier

    2014-05-01

    means of the Nash-Shutcliffe statistic [10]. This error estimation can be used to calibrate the input friction coefficients, providing an efficient tool for risk analysis in many regions of the world and specially in areas with steep topographic gradients such as mountain ranges, heavily incised river networks, coastal cliffs, etc. References: [1] H. J. Koerner, "Reichweite und geschwindigkeit von bergstürzen und fleisschneelawinen". Rock Mechanics, 8, 225-256 (1976) [2] P. J. McLellan and P. K. Kaiser, "Application of a two-parameter model to rock avalanches in the mackenzine mountains". 4th International Symposium on Landslides, 135-140 (1984). [3] A. Kent and O. Hungr, "Runout characteristics of debris from dump failures in mountainous terrain: stage 2: analysis, modelling and prediction". British Columbia Mine Waste Rock Pile Research Committee and CANMET (1995). [4] O. Hungr and S. G. Evans, "Rock avalanche runout prediction using a dynamic model". 7th International Symposium on Landslides, 233-238 (1996). [5] D. Rickenmann and T. Koch, "Comparison of debris flow modelling approaches". First International Conference on Debris-Flow Hazards Mitigation: Mechanics, Prediction, and Assessment. ASCE, ed. New York. C.L. Chen (1997). [6] P. Bertolo and G. F. Wieczorek, "Calibration of numerical models for small debris flows in Yosemite Valley, California, USA". Natural Hazards in Earth System Sciences (5) 993-1001 (2005). [7] S. Beguería and Th. J. van Asch and J. P. Malet and S. Gröndahl, "A GIS-based numerical model for simulating the kinematics of mud and debris flows over complex terrain". Natural Hazards in Earth System Sciences (9) 1897-1909 (2009). [8] G. Sánchez Burillo, S. Beguería, B. Latorre and J. Burguete, "Numerical treatment of the friction term in upwind schemes in debris flow runout modelling". ASCE Journal of Hydraulic Engineering (sent for publication). [9] A. Voellmy, Über die Zerstörungskraft von Lawinen. Schweizer. Bauzeitung (1955). [10] J. E

  5. 28th International Symposium on Shock Waves

    CERN Document Server

    2012-01-01

    The University of Manchester hosted the 28th International Symposium on Shock Waves between 17 and 22 July 2011. The International Symposium on Shock Waves first took place in 1957 in Boston and has since become an internationally acclaimed series of meetings for the wider Shock Wave Community. The ISSW28 focused on the following areas: Blast Waves, Chemically Reacting Flows, Dense Gases and Rarefied Flows, Detonation and Combustion, Diagnostics, Facilities, Flow Visualisation, Hypersonic Flow, Ignition, Impact and Compaction, Multiphase Flow, Nozzle Flow, Numerical Methods, Propulsion, Richtmyer-Meshkov, Shockwave Boundary Layer Interaction, Shock Propagation and Reflection, Shock Vortex Interaction, Shockwave Phenomena and Applications, as well as Medical and Biological Applications. The two Volumes contain the papers presented at the symposium and serve as a reference for the participants of the ISSW 28 and individuals interested in these fields.

  6. Proceedings of the second ERDA statistical symposium

    Energy Technology Data Exchange (ETDEWEB)

    Tietjen, G.; Campbell, K. (comps.)

    1977-04-01

    The Second ERDA Statistical Symposium, sponsored by the Energy Research and Development Administration, was held at Oak Ridge, Tennessee, October 25-27, 1976. This was the second annual symposium designed to promote interlaboratory communications among ERDA statisticians as well as contacts with statisticians from other institutions. The proceedings of the first symposium, held at Los Alamos in November, 1975, have been published by Batelle Pacific Northwest Laboratories (BNWL-1986). Separate abstracts were prepared for seven of the papers in this proceeding, all going in ERDA Energy Research Abstracts (ERA) and two in Energy Abstracts for Policy Analysis (EAPA). The remaining four have already been cited in ERA and can be found by referring to CONF-761023-- in the report number index. (RWR)

  7. 6th International Symposium on Thermal Expansion

    CERN Document Server

    1978-01-01

    This 6th International Symposium on Thermal Expansion, the first outside the USA, was held on August 29-31, 1977 at the Gull Harbour Resort on Hecla Island, Manitoba, Canada. Symposium Chairman was Ian D. Peggs, Atomic Energy of Canada Limited, and our continuing sponsor was CINDAS/Purdue University. We made considerable efforts to broaden the base this year to include more users of expansion data but with little success. We were successful, however, in establishing a session on liquids, an area which is receiving more attention as a logical extension to the high-speed thermophysical property measurements on materials at temperatures close to their melting points. The Symposium had good international representation but the overall attendance was, disappointingly, relatively low. Neverthe­ less, this enhanced the informal atmosphere throughout the meeting with a resultant frank exchange of information and ideas which all attendees appreciated. A totally new item this year was the presentation of a bursary to ...

  8. 22nd DAE High Energy Physics Symposium

    CERN Document Server

    2018-01-01

    These proceedings gather invited and contributed talks presented at the XXII DAE-BRNS High Energy Physics (HEP) Symposium, which was held at the University of Delhi, India, on 12–16 December 2016. The contributions cover a variety of topics in particle physics, astroparticle physics, cosmology and related areas from both experimental and theoretical perspectives, namely (1) Neutrino Physics, (2) Standard Model Physics (including Electroweak, Flavour Physics), (3) Beyond Standard Model Physics, (4) Heavy Ion Physics & QCD (Quantum Chromodynamics), (5) Particle Astrophysics & Cosmology, (6) Future Experiments and Detector Development, (7) Formal Theory, and (8) Societal Applications: Medical Physics, Imaging, etc. The DAE-BRNS High Energy Physics Symposium, widely considered to be one of the leading symposiums in the field of Elementary Particle Physics, is held every other year in India and supported by the Board of Research in Nuclear Sciences (BRNS), Department of Atomic Energy (DAE), India. As man...

  9. 28th International Acoustical Imaging Symposium

    CERN Document Server

    André, Michael P; Andre, Michael; Arnold, Walter; Bamber, Jeff; Burov, Valentin; Chubachi, Noriyoshi; Erikson, Kenneth; Ermert, Helmut; Fink, Mathias; Gan, Woon S; Granz, Bernd; Greenleaf, James; Hu, Jiankai; Jones, Joie P; Khuri-Yakub, Pierre; Laugier, Pascal; Lee, Hua; Lees, Sidney; Levin, Vadim M; Maev, Roman; Masotti, Leonardo; Nowicki, Andrzej; O’Brien, William; Prasad, Manika; Rafter, Patrick; Rouseff, Daniel; Thijssen, Johan; Tittmann, Bernard; Tortoli, Piero; Steen, Anton; Waag, Robert; Wells, Peter; Acoustical Imaging

    2007-01-01

    The International Acoustical Imaging Symposium has been held continuously since 1968 as a unique forum for advanced research, promoting the sharing of technology, developments, methods and theory among all areas of acoustics. The interdisciplinary nature of the Symposium and the wide international participation are two of its main strengths. Scientists from around the world present their papers in an informal environment conducive to lively discussion and cross-fertilization. The fact that a loyal community of scientists has supported this Series since 1968 is evidence of its impact on the field. The Symposium Series continues to thrive in a busy calendar of scientific meetings without the infrastructure of a professional society. It does so because those who attend and those who rely on the Proceedings as a well-known reference work acknowledge its value. This Volume 28 of the Proceedings likewise contains an excellent collection of papers presented in six major categories, offering both a broad perspective ...

  10. 30th International Acoustical Imaging Symposium

    CERN Document Server

    Jones, Joie; Lee, Hua

    2011-01-01

    The International Symposium on Acoustical Imaging is a unique forum for advanced research, covering new technologies, developments, methods and theories in all areas of acoustics. This interdisciplinary Symposium has been taking place every two years since 1968. In the course of the years the proceedings volumes in the Acoustical Imaging Series have become a reference for cutting-edge research in the field. In 2009 the 30th International Symposium on Acoustical Imaging was held in Monterey, CA, USA, March 1-4. Offering both a broad perspective on the state-of-the-art as well as  in-depth research contributions by the specialists in the field, this Volume 30 in the Series contains an excellent collection of forty three papers presented in five major categories: Biomedical Imaging Acoustic Microscopy Non-Destructive Evaluation Systems Analysis Signal Analysis and Image Processing Audience Researchers in medical imaging and biomedical instrumentation experts.

  11. Interdisciplinary Symposium on Complex Systems

    CERN Document Server

    Zelinka, Ivan; Rössler, Otto

    2014-01-01

    The book you hold in your hands is the outcome of the "ISCS 2013: Interdisciplinary Symposium on Complex Systems" held at the historical capital of Bohemia as a continuation of our series of symposia in the science of complex systems. Prague, one of the most beautiful European cities, has its own beautiful genius loci. Here, a great number of important discoveries were made and many important scientists spent fruitful and creative years to leave unforgettable traces. The perhaps most significant period was the time of Rudolf II who was a great supporter of the art and the science and attracted a great number of prominent minds to Prague. This trend would continue. Tycho Brahe, Niels Henrik Abel, Johannes Kepler, Bernard Bolzano, August Cauchy Christian Doppler, Ernst Mach, Albert Einstein and many others followed developing fundamental mathematical and physical theories or expanding them. Thus in the beginning of the 17th century, Kepler formulated here the first two of his three laws of planetary motion on ...

  12. Symposium 1 of JENAM 2010

    CERN Document Server

    Molaro, Paolo; From Varying Couplings to Fundamental Physics

    2011-01-01

    Nature is characterized by a number of physical laws and fundamental dimensionless couplings. These determine the  properties of our physical universe, from the size of atoms, cells and mountains to the ultimate fate of the universe as a whole. Yet it is rather remarkable how little we know about them. The constancy of physical laws is one of the cornerstones of the scientific research method, but for fundamental couplings this is an assumption with no other justification  than a historical assumption. There is no 'theory of constants' describing their role in the underlying theories and how they relate to one another or how many  of them are truly fundamental.  Studying the behaviour of these quantities throughout the history of the universe is an effective way to probe fundamental physics. This explains why the ESA and ESO include varying fundamental constants among their key science drivers for the next generation of facilities. This symposium discussed the state-of-the-art in the field, as well as the...

  13. Fourth international radiopharmaceutical dosimetry symposium

    International Nuclear Information System (INIS)

    Schlafke-Stelson, A.T.; Watson, E.E.

    1986-04-01

    The focus of the Fourth International Radiopharmaceutical Dosimetry Symposium was to explore the impact of current developments in nuclear medicine on absorbed dose calculations. This book contains the proceedings of the meeting including the edited discussion that followed the presentations. Topics that were addressed included the dosimetry associated with radiolabeled monoclonal antibodies and blood elements, ultrashort-lived radionuclides, and positron emitters. Some specific areas of discussion were variations in absorbed dose as a result of alterations in the kinetics, the influence of radioactive contaminants on dose, dose in children and in the fetus, available instrumentation and techniques for collecting the kinetic data needed for dose calculation, dosimetry requirements for the review and approval of new radiopharmaceuticals, and a comparison of the effect on the thyroid of internal versus external irradiation. New models for the urinary blader, skeleton including the active marrow, and the blood were presented. Several papers dealt with the validity of traditional ''average-organ'' dose estimates to express the dose from particulate radiation that has a short range in tissue. These problems are particularly important in the use of monoclonal antibodies and agents used to measure intracellular functions. These proceedings have been published to provide a resource volume for anyone interested in the calculation of absorbed radiation dose

  14. 2. Symposium environmental geotechnics. Papers

    International Nuclear Information System (INIS)

    Klapperich, H.; Katzenbach, R.; Witt, K.J.; Griessl, D.

    2005-01-01

    The 2nd symposium of the chapter section 'Environmental Geotechnics' of DGGT follows the event in Weimar 2003 and focuses on the central topics of Landfill - Contaminated Sites - Brownfields. The stream 'Waste management - Waste Site technology' discusses legal requirements and technical alternatives, especially in view of many upcoming closures of landfill sites and associated surface sealing, as well as technical reports of case studies and developments. The contribution 'Ultimate storage of radioactive waste' illustrates the wider dimensions to geotechnical questions. Between the streams of 'Remediation Techniques' and 'Land Recycling/Land Management' a panel discussion 'From Brownfield Remediation to Land Management' is taking place. The aim is to discuss the way forward and the need to take up the opportunity for future town planning as well as the design of conversion sites and expansive former mining areas. Representatives of authorities involved and project participants have submitted their statements in advance to the following question: 1.) status of remediation - research and practice 2.) what practical significance is attributed to different remediation techniques for the remediation of brownfields? 3.) modern town planning/redevelopment of former mining areas - spatial planning - real estate economy - financing models for redeveloping land - which parameters/instruments work? (orig.)

  15. Summary of Symposium on Cloud Systems, Hurricanes and TRMM: Celebration of Dr. Joanne Simpson's Career, The First Fifty Years

    Science.gov (United States)

    Tao, W.-K.; Adler, R.; Braun, S.; Einaudi, F.; Ferrier, B.; Halverson, J.; Heymsfield, G.; Kummerow, C.; Negri, A.; Kakar, R.; hide

    2000-01-01

    A symposium celebrating the first 50 years of Dr. Joanne Simpson's career took place at the NASA/Goddard Space Flight Center from December 1 - 3, 1999. This symposium consisted of presentations that focused on: historical and personal points of view concerning Dr. Simpson's research career, her interactions with the American Meteorological Society, and her leadership in TRMM; scientific interactions with Dr. Simpson that influenced personal research; research related to observations and modeling of clouds, cloud systems and hurricanes; and research related to the Tropical Rainfall Measuring Mission (TRMM). There were a total of 36 presentations and 103 participants from the US, Japan and Australia. The specific presentations during the symposium are summarized in this paper.

  16. Protecting AREVA ATRIUM™ BWR fuel from debris fretting failure

    International Nuclear Information System (INIS)

    Cole, Steven E.; Garner, Norman L.; Lippert, Hans-Joachim; Graebert, Rüdiger; Mollard, Pierre; Hahn, Gregory C.

    2014-01-01

    Historically, debris fretting has been the leading cause of fuel rod failure in BWR fuel assemblies, costing the industry millions of dollars in lost generation and negatively impacting the working area of plant site personnel. In this paper the focus will be on recent BWR fuel product innovation designed to eliminate debris related failures. Experience feedback from more than three decades of operation history with non-line-of-sight FUELGUARD™ lower tie plate debris filters will be presented. The development and relative effectiveness of successive generations of filtration technology will be discussed. It will be shown that modern, state of the art debris filters are an effective defense against debris fretting failure. Protective measures extend beyond inlet nozzle debris filters. The comprehensive debris resistance features built into AREVA’s newest fuel design, the ATRIUM™ 11, reduce the overall risk of debris entrapment as well as providing a degree of protection from debris that may fall down on the fuel assembly from above, e.g., during refueling operations. The positive recent experience in a debris sensitive plant will be discussed showing that the combination of advanced fuel technology and a robust foreign material exclusion program at the reactor site can eliminate the debris fretting failure mechanism. (author)

  17. [Research progress in post-fire debris flow].

    Science.gov (United States)

    Di, Xue-ying; Tao, Yu-zhu

    2013-08-01

    The occurrence of the secondary disasters of forest fire has significant impacts on the environment quality and human health and safety. Post-fire debris flow is one of the most hazardous secondary disasters of forest fire. To understand the occurrence conditions of post-fire debris flow and to master its occurrence situation are the critical elements in post-fire hazard assessment. From the viewpoints of vegetation, precipitation threshold and debris flow material sources, this paper elaborated the impacts of forest fire on the debris flow, analyzed the geologic and geomorphic conditions, precipitation and slope condition that caused the post-fire debris flow as well as the primary mechanisms of debris-flow initiation caused by shallow landslide or surface runoff, and reviewed the research progress in the prediction and forecast of post-fire debris flow and the related control measures. In the future research, four aspects to be focused on were proposed, i. e., the quantification of the relationships between the fire behaviors and environmental factors and the post-fire debris flow, the quantitative research on the post-fire debris flow initiation and movement processes, the mechanistic model of post-fire debris flow, and the rapid and efficient control countermeasures of post-fire debris flow.

  18. Abandoned polluted areas symposium 2005. Proceedings; Altlastensymposium 2005. Tagungsband

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The reduction of the demand on space for settlement and traffic as well as the improvement of cities and rural settlement structures are the most important key questions and challenges of current environmental policy. An intelligent utilisation of the limited resource space is not only related with positive effects of soil protection (Protection of the ''Green Field''). Measures for estate development on industrial, business and settlement fallow grounds contribute to support a long-lasting city development as well to an economic development. In order to improve the re-integration of pre-used land holdings into the real estate business appropriate legal, planning, financial, tax and incentive instruments are required as well as supplemental measures and activity fields like tradable space certification rights, model projects, research incentives, an optimised space management and improved public work. In the frame of this symposium experts report on their experience in the field of space reactivation of large industrial sites and allow for a discussion of their risks, chances and the resulting challenges. A main focus of the conference programme will be the affects of the present European legal guidelines on water and soil protection. (orig.)

  19. 2016 AMS Mario J. Molina Symposium

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Renyi [Texas A & M Univ., College Station, TX (United States)

    2016-11-29

    A named symposium to honor Dr. Mario J. Molina was held 10–14 January 2016, as part of the 96th American Meteorological Society (AMS) Annual Meeting in New Orleans, Louisiana. Dr. Molina first demonstrated that industrially produced chlorofluorocarbons (CFCs) decompose in the stratosphere and release chlorine atoms, leading to catalytic ozone destruction. His research in stratospheric chemistry was instrumental to the establishment of the 1987 United Nations Montreal Protocol to ban ozone-depleting substances worldwide. Dr. Molina’s contributions to preserving the planet Earth not only save the atmospheric ozone layer, but also protect the climate by reducing the emissions of greenhouse gases. He was awarded the 1995 Nobel Prize in Chemistry for his pioneering research in understanding the stratospheric ozone loss mechanism. In 2013, President Barack Obama announced Dr. Molina as a recipient of the Presidential Medal of Freedom. The 2016 AMS Molina Symposium honored Dr. Molina’s distinguished contributions to research related to atmospheric chemistry. The symposium contained an integrated theme related to atmospheric chemistry, climate, and policy. Dr. Molina delivered a keynote speech at the Symposium. The conference included invited keynote speeches and invited and contributed oral and poster sessions, and a banquet was held on Tuesday January 12, 2016. The symposium covered all aspects of atmospheric chemistry, with topics including (1) Stratospheric chemistry, (2) Tropospheric chemistry, (3) Aerosol nucleation, growth, and transformation, (4) Aerosol properties, (5) Megacity air pollution, and (6) Atmospheric chemistry laboratory, field, and modeling studies. This DOE project supported 14 scientists, including graduate students, post docs, junior research scientists, and non-tenured assistant professors to attend this symposium.

  20. Impact Forces from Tsunami-Driven Debris

    Science.gov (United States)

    Ko, H.; Cox, D. T.; Riggs, H.; Naito, C. J.; Kobayashi, M. H.; Piran Aghl, P.

    2012-12-01

    Debris driven by tsunami inundation flow has been known to be a significant threat to structures, yet we lack the constitutive equations necessary to predict debris impact force. The objective of this research project is to improve our understanding of, and predictive capabilities for, tsunami-driven debris impact forces on structures. Of special interest are shipping containers, which are virtually everywhere and which will float even when fully loaded. The forces from such debris hitting structures, for example evacuation shelters and critical port facilities such as fuel storage tanks, are currently not known. This research project focuses on the impact by flexible shipping containers on rigid columns and investigated using large-scale laboratory testing. Full-scale in-air collision experiments were conducted at Lehigh University with 20 ft shipping containers to experimentally quantify the nonlinear behavior of full scale shipping containers as they collide into structural elements. The results from the full scale experiments were used to calibrate computer models and used to design a series of simpler, 1:5 scale wave flume experiments at Oregon State University. Scaled in-air collision tests were conducted using 1:5 scale idealized containers to mimic the container behavior observed in the full scale tests and to provide a direct comparison to the hydraulic model tests. Two specimens were constructed using different materials (aluminum, acrylic) to vary the stiffness. The collision tests showed that at higher speeds, the collision became inelastic as the slope of maximum impact force/velocity decreased with increasing velocity. Hydraulic model tests were conducted using the 1:5 scaled shipping containers to measure the impact load by the containers on a rigid column. The column was instrumented with a load cell to measure impact forces, strain gages to measure the column deflection, and a video camera was used to provide the debris orientation and speed. The

  1. Characterization of Orbital Debris Photometric Properties Derived from Laboratory-Based Measurements

    Science.gov (United States)

    Cowardin, H.; Abercromby, K.; Barker, E.; Seitzer, P.; Schildknecht, T.

    2010-01-01

    To better characterize and model optical data acquired from ground-based telescopes, the Optical Measurements Center (OMC) at NASA/JSC attempts to emulate illumination conditions seen in space using equipment and techniques that parallel telescopic observations and source-target-sensor orientations. The OMC uses a 75 Watt Xenon arc lamp as a solar simulator, an SBIG CCD camera with standard Johnson/Bessel filters, and a robotic arm to simulate an object's position and rotation. The laboratory uses known shapes, materials suspected to be consistent with the orbital debris population, and three phase angles to best match the lighting conditions of the telescope based data. The fourteen objects studied in the laboratory are fragments or materials acquired through ground-tests of scaled-model satellites/rocket bodies as well as material samples in more/less "flight-ready" condition. All fragments were measured at 10 increments in a full 360 rotation at 6 , 36 , and 60 phase angles. This paper will investigate published color photometric data for a series of orbital debris targets and compare it to the empirical photometric measurements generated in the OMC. Using the data acquired over specific rotational angles through different filters (B, V, R, I), a color index is acquired (B-R, R-I). Using these values and their associated lightcurves, this laboratory data is compared to observational data obtained on the 1 m telescope of the Astronomical Institute of the University of Bern (AUIB), the 0.9 m operated by the Small- and Medium-Aperture Research Telescope System (SMARTS) Consortium and the Curtis-Schmidt 0.6 m Michigan Orbital Debris Space Debris Telescope both located at Cerro Tololo Inter-American Observatory (CTIO). An empirical based optical characterization model will be presented to provide preliminary correlations between laboratory based and telescope-based data in the context of classification of GEO debris objects.

  2. 11th AG STAB/DGLR Symposium

    CERN Document Server

    Heinemann, Hans-Joachim; Hilbig, Reinhard

    1999-01-01

    This volume contains the papers of the 11th Symposium of the AG STAB (German Aerospace Aerodynamics Association). In this association those scientists and engineers from universities, research-establishments and industry are involved, who are doing research and project work in numerical and experimental fluid mechanics and aerodynamics for aerospace and other applications. Many of the contributions are giving results from the "Luftfahrtforschungsprogramm der Bundesregierung (German Aeronautical Research Programme). Some of the papers report on work sponsored by the Deutsche Forschungsgemeinschaft, DFG, which also was presented at the symposium. The volume gives a broad overview over the ongoing work in this field in Germany.

  3. Transport arrangements for the scientific symposium

    CERN Multimedia

    2000-01-01

    Parking in the region of building 180 will be severely restricted during the LEPFest scientific symposium of 10-11 October, and a special bus service will operate to ferry people to and from the event. From 8:00 am, buses will leave the reception at building 33, stop to pickup passengers outside the hostels (buildings 38 and 39), and drop people off at the symposium venue - building 180. At the end of each day’s proceedings, the buses will bring people back, and through out the day a shuttle service will operate around every 15-20 minutes. Attendees are strongly recommended to use the buses.

  4. Outcome of UNIDO symposium on biomass energy

    International Nuclear Information System (INIS)

    Nazemi, A.H.

    1997-01-01

    The results of the UNIDO symposium are presented. The symposium covered a variety of subjects, beginning with a comparison of biomass energy production and potential uses in different regions, specific country case studies about the present situation and trends in biomass energy utilisation. Technological aspects discussed included the production of biomass resources, their conversion into energy carriers and technology transfer to developing countries. An analysis of financial resources available and mechanisms for funding biomass projects were given. Environmental effects and some relatively successful biomass projects under development were described. (K.A.)

  5. Proceedings of the international symposium NUCEF 2005

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-08-01

    Japan Atomic Energy Research Institute (JAERI) held the international symposium NUCEF 2005 at Techno Community Square RICOTTI in Tokai-mura on February 9 and 10, 2005. This symposium was co-organized by Japan Nuclear Cycle Development Institute (JNC), and Nuclear Fuel Cycle Safety Research Committee authorized the program. Two hundred thirty-nine participants from 11 countries presented fifty-nine papers, and discussed recent research activities and its outputs on waste disposal safety, fuel cycle facility safety including criticality safety, and separation process development. The presented papers are compiled in the proceedings. (author)

  6. Symposium on high temperature and materials chemistry

    International Nuclear Information System (INIS)

    1989-10-01

    This volume contains the written proceedings of the Symposium on High Temperature and Materials Chemistry held in Berkeley, California on October 24--25, 1989. The Symposium was sponsored by the Materials and Chemical Sciences Division of Lawrence Berkeley Laboratory and by the College of Chemistry of the University of California at Berkeley to discuss directions, trends, and accomplishments in the field of high temperature and materials chemistry. Its purpose was to provide a snapshot of high temperature and materials chemistry and, in so doing, to define status and directions

  7. Quality assurance and demolition: 2006 symposium

    International Nuclear Information System (INIS)

    Thierfeldt, S.

    2006-01-01

    The '2006 Symposium: Quality Assurance and Demolition' jointly organized by compra GmbH and Brenk Systemplanung GmbH this year again focused on quality assurance and the demolition of nuclear facilities as its main topics. The papers presented ranged from issues of clearance and disposal to demolition technologies and status reports about specific demolition projects. The sixteen presentations at the '2006 Symposium: Quality Assurance and Demolition' offered an interesting and very topical cross section of decommissioning and demolition of nuclear facilities in Germany. In 2007, the conference about similar main topics will again be held at the Schloss Bensberg Grand Hotel. (orig.)

  8. Eleventh symposium on energy engineering sciences: Proceedings

    International Nuclear Information System (INIS)

    1993-01-01

    The Eleventh Symposium on Energy Engineering Sciences was held on May 3--5, 1993, at the Argonne National Laboratory, Argonne, Illinois. These proceedings include the program, list of participants, and the papers that were presented during the eight technical sessions held at this meeting. This symposium was organized into eight technical sessions: Surfaces and interfaces; thermophysical properties and processes; inelastic behavior; nondestructive characterization; multiphase flow and thermal processes; optical and other measurement systems; stochastic processes; and large systems and control. Individual projects were processed separately for the databases

  9. Symposium on high temperature and materials chemistry

    Energy Technology Data Exchange (ETDEWEB)

    1989-10-01

    This volume contains the written proceedings of the Symposium on High Temperature and Materials Chemistry held in Berkeley, California on October 24--25, 1989. The Symposium was sponsored by the Materials and Chemical Sciences Division of Lawrence Berkeley Laboratory and by the College of Chemistry of the University of California at Berkeley to discuss directions, trends, and accomplishments in the field of high temperature and materials chemistry. Its purpose was to provide a snapshot of high temperature and materials chemistry and, in so doing, to define status and directions.

  10. 2. symposium energy crops 2009; 2. Symposium Energiepflanzen 2009

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-27

    Within the meeting '2nd Symposium energy plants 2009', held at 17th to 18th November, 2009, in Berlin (Federal Republic of Germany), the following lectures were held: (1) The bio energy policy of the Federal Government in the area of attention between climatic protection, ecology and economy (Ilse Aigner); (2) Chances and threatens of cultivation of energy plants for a sustainable energy supply (Alois Heissenhuber); (3) Certification as a prerequisite of the global exploration of bio energy (Andreas Feige); (4) A project support in the field of cultivation of energy plants, a review (Andreas Schuette); (5) Results from the investigation of the crop rotation in the EVA network (Armin Vater); (6) Optimisation of the cultivation technology of sorghum millets (Christian Roehricht); (7) The two-culture utilization system - a comparison between ecologic and conventional cultivation (Reinhold Stuelpnagel); (8) Crop rotation with energy plants - Chances and threatens for the plant protection (Baerbel Gerowitt); (9) Efficiency of utilization of water for energy plants (Siegfried Schittenhelm); (10) Utilization of arable food grasses and permanent grassland as a substrate for biogas (Matthias Benke); (11) Economical evaluation of plant fermentation substrates (Dominik Reus); (12) Energy plants as a challenge for the agricultural engineering (Heiner Bruening); (13) Influence of the design of cultivation on the subsequent effects of the cultivation of energy plants (Michael Glemnitz); (14) Energy plants and waters protection - Key aspects and possible options of action (Heike Nitsch); (15) Neophytes as energy plants - Chances and threatens (Werner Kuhn); (16) Manifold in te landscape - extensive cultivation systems with renewable raw materials as an option for nature protection? (Peer Heck); (17) Ecologic aspects of agro forestry systems (Holger Gruenewald); (18) Enhancement of the potential of energy yield of winter wheat (Wolfgang Friedt); (19) Interspersed silphie

  11. Assessing accumulated hard-tissue debris using micro-computed tomography and free software for image processing and analysis.

    Science.gov (United States)

    De-Deus, Gustavo; Marins, Juliana; Neves, Aline de Almeida; Reis, Claudia; Fidel, Sandra; Versiani, Marco A; Alves, Haimon; Lopes, Ricardo Tadeu; Paciornik, Sidnei

    2014-02-01

    The accumulation of debris occurs after root canal preparation procedures specifically in fins, isthmus, irregularities, and ramifications. The aim of this study was to present a step-by-step description of a new method used to longitudinally identify, measure, and 3-dimensionally map the accumulation of hard-tissue debris inside the root canal after biomechanical preparation using free software for image processing and analysis. Three mandibular molars presenting the mesial root with a large isthmus width and a type II Vertucci's canal configuration were selected and scanned. The specimens were assigned to 1 of 3 experimental approaches: (1) 5.25% sodium hypochlorite + 17% EDTA, (2) bidistilled water, and (3) no irrigation. After root canal preparation, high-resolution scans of the teeth were accomplished, and free software packages were used to register and quantify the amount of accumulated hard-tissue debris in either canal space or isthmus areas. Canal preparation without irrigation resulted in 34.6% of its volume filled with hard-tissue debris, whereas the use of bidistilled water or NaOCl followed by EDTA showed a reduction in the percentage volume of debris to 16% and 11.3%, respectively. The closer the distance to the isthmus area was the larger the amount of accumulated debris regardless of the irrigating protocol used. Through the present method, it was possible to calculate the volume of hard-tissue debris in the isthmuses and in the root canal space. Free-software packages used for image reconstruction, registering, and analysis have shown to be promising for end-user application. Copyright © 2014. Published by Elsevier Inc.

  12. Space space space

    CERN Document Server

    Trembach, Vera

    2014-01-01

    Space is an introduction to the mysteries of the Universe. Included are Task Cards for independent learning, Journal Word Cards for creative writing, and Hands-On Activities for reinforcing skills in Math and Language Arts. Space is a perfect introduction to further research of the Solar System.

  13. Symposium report of Inter-COE international symposium on energy systems

    International Nuclear Information System (INIS)

    2006-10-01

    The symposium of the title aims to discuss a comprehensive possibility of energy system technologies for future society utilizing both specialties of five COEs in energy technology field. The symposium topics include, 'Primary energy production', 'Energy conversion, storage and transportation', 'Energy materials', 'Energy system' by specialists from the COEs. Posters were presented by doctoral course students and others in the COEs, in addition special session 'Energy Research and Human Resources Development'. (J.P.N.)

  14. Counter-orbiting tidal debris as the origin of the MW DoS

    Directory of Open Access Journals (Sweden)

    Pawlowski M.S.

    2012-02-01

    Full Text Available The Milky Way satellite galaxies show a phase-space distribution that is not expected from the standard scenario of galaxy formation. This is a strong hint at them being of tidal origin, which would naturally explain their spacial distribution in a disc of satellites. It is shown that also their orbital directions can be reproduced with the debris of galaxy collisions. Both co- and counter-orbiting satellites are formed naturally in merger and fly-by interactions.

  15. NASA's Newest Orbital Debris Ground-based Telescope Assets: MCAT and UKIRT

    Science.gov (United States)

    Lederer, S.; Frith, J.; Pace, L. F.; Cowardin, H. M.; Hickson, P.; Glesne, T.; Maeda, R.; Buckalew, B.; Nishimoto, D.; Douglas, D.; Stansbery, E. G.

    2014-09-01

    NASAs Orbital Debris Program Office (ODPO) will break ground on Ascension Island in 2014 to build the newest optical (0.30 1.06 microns) ground-based telescope asset dedicated to the study of orbital debris. The Meter Class Autonomous Telescope (MCAT) is a 1.3m optical telescope designed to track objects in orbits ranging from Low Earth Orbit (LEO) to Geosynchronous Earth Orbit (GEO). Ascension Island is located in the South Atlantic Ocean, offering longitudinal sky coverage not afforded by the Ground-based Electro-Optical Deep Space Surveillance (GEODSS) network. With a fast-tracking dome, a suite of visible wide-band filters, and a time-delay integration (TDI) capable camera, MCAT is capable of multiple observing modes ranging from tracking cataloged debris targets to surveying the overall debris environment. Access to the United Kingdom Infrared Telescope (UKIRT) will extend our spectral coverage into the near- (0.8-5 micron) and mid- to far-infrared (8-25 micron) regime. UKIRT is a 3.8m telescope located on Mauna Kea on the Big Island of Hawaii. At nearly 14,000-feet and above the atmospheric inversion layer, this is one of the premier astronomical sites in the world and is an ideal setting for an infrared telescope. An unprecedented one-third of this telescopes time has been allocated to collect orbital debris data for NASAs ODPO over a 2-year period. UKIRT has several instruments available to obtain low-resolution spectroscopy in both the near-IR and the mid/far-IR. Infrared spectroscopy is ideal for constraining the material types, albedos and sizes of debris targets, and potentially gaining insight into reddening effects caused by space weathering. In addition, UKIRT will be used to acquire broadband photometric imaging at GEO with the Wide Field Camera (WFCAM) for studying known objects of interest as well as collecting data in survey-mode to discover new targets. Results from the first stage of the debris campaign will be presented. The combination of

  16. Warm Debris Disk Candidates from WISE

    Science.gov (United States)

    Padgett, Deborah; Stapelfeldt, Karl; Liu, Wilson; Leisawitz, David

    2011-01-01

    The Wide Field Infrared Survey Explorer (WISE) has just completed a sensitive all-sky survey in photometric bands at 3.4, 4.6, 12, and 22 microns. We report on a preliminary investigation of main sequence Hipparcos and Tycho catalog stars with 22 micron emission in excess of photospheric levels. This warm excess emission traces material in the circumstellar region likely to host terrestrial planets and is preferentially found in young systems with ages warm debris disk candidates are detected among FGK stars and 150 A stars within 120 pc. We are in the process of obtaining spectra to determine spectral types and activity level of these stars and are using HST, Herschel and Keck to characterize the dust, multiplicity, and substellar companions of these systems. In this contribution, we will discuss source selection methods and individual examples from among the WISE debris disk candidates.

  17. Rocky Planetary Debris Around Young WDs

    Science.gov (United States)

    Gaensicke, B.

    2014-04-01

    The vast majority of all known planet host stars, including the Sun, will eventually evolve into red giants and finally end their lives as white dwarfs: extremely dense Earth-sized stellar embers. Only close-in planets will be devoured during the red-giant phase. In the solar system, Mars, the asteroid belt, and all the giant planets will escape evaporation, and the same is true for many of the known exo-planets. It is hence certain that a significant fraction of the known white dwarfs were once host stars to planets, and it is very likely that many of them still have remnants of planetary systems. The detection of metals in the atmospheres of white dwarfs is the unmistakable signpost of such evolved planetary systems. The strong surface gravity of white dwarfs causes metals to sink out of the atmosphere on time-scales much shorter than their cooling ages, leading unavoidably to pristine H/He atmospheres. Therefore any metals detected in the atmosphere of a white dwarf imply recent or ongoing accretion of planetary debris. In fact, planetary debris is also detected as circumstellar dust and gas around a number of white dwarfs. These debris disks are formed from the tidal disruption of asteroids or Kuiper belt-like objects, stirred up by left-over planets, and are subsequently accreted onto the white dwarf, imprinting their abundance pattern into its atmosphere. Determining the photospheric abundances of debris-polluted white dwarfs is hence entirely analogue to the use of meteorites, "rocks that fell from the sky", for measuring the abundances of planetary material in the solar system. I will briefly review this new field of exo-planet science, and then focus on the results of a large, unbiased COS snapshot survey of relatively young ( 20-100Myr) white dwarfs that we carried out in Cycle 18/19. * At least 30% of all white dwarfs in our sample are accreting planetary debris, and that fraction may be as high as 50%. * In most cases where debris pollution is detected

  18. Proceedings of the third annual underground coal conversion symposium

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-01-01

    The Third Annual Underground Coal Conversion Symposium was held at Fallen Leaf Lake, CA, June 6--9, 1977. It was sponsored by the U.S. Department of Energy and hosted by Lawrence Livermore Laboratory. Forty-one papers have been entered individually into EDB and ERA; ten papers had been entered previously from other sources. The papers cover the in-situ gasification of lignite, subbituminous coal and bituminous coal, in flat lying seams and a steeply dipping beds, at moderate and at greater depths, and describe various technologies of (borehole linking, well spacings, gasifying agents (air, oxygen, steam, hydrogen, including mixtures). Measuring instruments for diagnostic and process control purposes are described. Environmental impacts (ground subsidence and possible groundwater pollution) are the subject of several papers. Finally, mathematical modelling and projected economics of the process are developed. (LTN)

  19. The mechanics of motorised momentum exchange tethers when applied to active debris removal from LEO

    Energy Technology Data Exchange (ETDEWEB)

    Caldecott, Ralph; Kamarulzaman, Dayangku N. S.; Kirrane, James P.; Cartmell, Matthew P.; Ganilova, Olga A. [Department of Mechanical Engineering, University of Sheffield, Mappin St., Sheffield, S1 3JD, England (United Kingdom)

    2014-12-10

    The concept of momentum exchange when applied to space tethers for propulsion is well established, and a considerable body of literature now exists on the on-orbit modelling, the dynamics, and also the control of a large range of tether system applications. The authors consider here a new application for the Motorised Momentum Exchange Tether by highlighting three key stages of development leading to a conceptualisation that can subsequently be developed into a technology for Active Debris Removal. The paper starts with a study of the on-orbit mechanics of a full sized motorised tether in which it is shown that a laden and therefore highly massasymmetrical tether can still be forced to spin, and certainly to librate, thereby confirming its possible usefulness for active debris removal (ADR). The second part of the paper concentrates on the modelling of the centripetal deployment of a symmetrical MMET in order to get it initialized for debris removal operations, and the third and final part of the paper provides an entry into scale modelling for low cost mission design and testing. It is shown that the motorised momentum exchange tether offers a potential solution to the removal of large pieces of orbital debris, and that dynamic methodologies can be implemented to in order to optimise the emergent design.

  20. Ultrastructural and clinical evidence of subretinal debris accumulation in type 2 macular telangiectasia.

    Science.gov (United States)

    Cherepanoff, Svetlana; Killingsworth, Murray C; Zhu, Meidong; Nolan, Timothy; Hunyor, Alex P; Young, Stephanie H; Hageman, Gregory S; Gillies, Mark C

    2012-11-01

    To describe subretinal debris found on ultrastructural examination in an eye with macular telangiectasia (MacTel) type 2 and on optical coherence tomography (OCT) in a subset of patients with MacTel type 2. Blocks from the mid-periphery and temporal perifovea of an eye with clinically documented MacTel type 2 were examined with electron microscopy (EM). Cases came from the Sydney centre of the MacTel project and the practices of the authors. On EM examination, subretinal debris was found in the perifovea with accumulation of degenerate photoreceptor elements in the subretinal space. Despite the substantial subretinal debris, there was minimal retinal pigment epithelial (RPE) reaction. Focal defects were seen in the inner limiting membrane in the perifovea. Of the 65 Sydney MacTel project participants, three (5%) had prominent yellow material at the fovea. OCT revealed smooth mounds between the RPE and the ellipsoid region. The material was hyperautofluorescent. This study suggests that subretinal accumulation of photoreceptor debris may be a feature of MacTel type 2. Ultrastructural and OCT evidence of disease beyond the vasculature, involving photoreceptors and Muller cells, is presented.

  1. The mechanics of motorised momentum exchange tethers when applied to active debris removal from LEO

    International Nuclear Information System (INIS)

    Caldecott, Ralph; Kamarulzaman, Dayangku N. S.; Kirrane, James P.; Cartmell, Matthew P.; Ganilova, Olga A.

    2014-01-01

    The concept of momentum exchange when applied to space tethers for propulsion is well established, and a considerable body of literature now exists on the on-orbit modelling, the dynamics, and also the control of a large range of tether system applications. The authors consider here a new application for the Motorised Momentum Exchange Tether by highlighting three key stages of development leading to a conceptualisation that can subsequently be developed into a technology for Active Debris Removal. The paper starts with a study of the on-orbit mechanics of a full sized motorised tether in which it is shown that a laden and therefore highly massasymmetrical tether can still be forced to spin, and certainly to librate, thereby confirming its possible usefulness for active debris removal (ADR). The second part of the paper concentrates on the modelling of the centripetal deployment of a symmetrical MMET in order to get it initialized for debris removal operations, and the third and final part of the paper provides an entry into scale modelling for low cost mission design and testing. It is shown that the motorised momentum exchange tether offers a potential solution to the removal of large pieces of orbital debris, and that dynamic methodologies can be implemented to in order to optimise the emergent design

  2. Using Light Curves to Characterize Size and Shape of Pseudo-Debris

    Science.gov (United States)

    Rodriquez, Heather M.; Abercromby, Kira J.; Jarvis, Kandy S.; Barker, Edwin

    2006-01-01

    Photometric measurements were collected for a new study aimed at estimating orbital debris sizes based on object brightness. To obtain a size from optical measurements the current practice is to assume an albedo and use a normalized magnitude to calculate optical size. However, assuming a single albedo value may not be valid for all objects or orbit types; material type and orientation can mask an object s true optical cross section. This experiment used a CCD camera to record data, a 300 W Xenon, Ozone Free collimated light source to simulate solar illumination, and a robotic arm with five degrees of freedom to move the piece of simulated debris through various orientations. The pseudo-debris pieces used in this experiment originate from the European Space Operations Centre s ESOC2 ground test explosion of a mock satellite. A uniformly illuminated white ping-pong ball was used as a zero-magnitude reference. Each debris piece was then moved through specific orientations and rotations to generate a light curve. This paper discusses the results of five different object-based light curves as measured through an x-rotation. Intensity measurements, from which each light curve was generated, were recorded in five degree increments from zero to 180 degrees. Comparing light curves of different shaped and sized pieces against their characteristic length establishes the start of a database from which an optical size estimation model will be derived in the future.

  3. Plastic debris in the open ocean

    OpenAIRE

    Cózar, Andrés; Echevarría, Fidel; González-Gordillo, J. Ignacio; Irigoien, Xabier; Úbeda, Bárbara; Hernández-León, Santiago; Palma, Álvaro T.; Navarro, Sandra; García-de-Lomas, Juan; Ruiz, Andrea; Fernández-de-Puelles, María L.; Duarte, Carlos M.

    2014-01-01

    There is a rising concern regarding the accumulation of floating plastic debris in the open ocean. However, the magnitude and the fate of this pollution are still open questions. Using data from the Malaspina 2010 circumnavigation, regional surveys, and previously published reports, we show a worldwide distribution of plastic on the surface of the open ocean, mostly accumulating in the convergence zones of each of the five subtropical gyres with comparable density. Howeve...

  4. Optimized debris stoppers for Z-pinches

    Energy Technology Data Exchange (ETDEWEB)

    Gondarenko, N A; Pereira, N R [Berkeley Research Associates, Springfield, VA (United States)

    1997-12-31

    A pulse power generator discharging through an array of wires or a gas cylinder creates a pulse of useful soft x-rays, which is usually followed by deleterious byproducts such as plasma, hot gases and droplets of metal from evaporated electrodes. Separating the extraneous material from the x-rays is done with a debris shield. Optimization of such shields is discussed. (author). 3 figs., 3 refs.

  5. MOLECULAR GAS IN YOUNG DEBRIS DISKS

    International Nuclear Information System (INIS)

    Moor, A.; Abraham, P.; Kiss, Cs.; Juhasz, A.; Kospal, A.; Pascucci, I.; Apai, D.; Henning, Th.; Csengeri, T.; Grady, C.

    2011-01-01

    Gas-rich primordial disks and tenuous gas-poor debris disks are usually considered as two distinct evolutionary phases of the circumstellar matter. Interestingly, the debris disk around the young main-sequence star 49 Ceti possesses a substantial amount of molecular gas and possibly represents the missing link between the two phases. Motivated to understand the evolution of the gas component in circumstellar disks via finding more 49 Ceti-like systems, we carried out a CO J = 3-2 survey with the Atacama Pathfinder EXperiment, targeting 20 infrared-luminous debris disks. These systems fill the gap between primordial and old tenuous debris disks in terms of fractional luminosity. Here we report on the discovery of a second 49 Ceti-like disk around the 30 Myr old A3-type star HD21997, a member of the Columba Association. This system was also detected in the CO(2-1) transition, and the reliable age determination makes it an even clearer example of an old gas-bearing disk than 49 Ceti. While the fractional luminosities of HD21997 and 49 Ceti are not particularly high, these objects seem to harbor the most extended disks within our sample. The double-peaked profiles of HD21997 were reproduced by a Keplerian disk model combined with the LIME radiative transfer code. Based on their similarities, 49 Ceti and HD21997 may be the first representatives of a so far undefined new class of relatively old (∼>8 Myr), gaseous dust disks. From our results, neither primordial origin nor steady secondary production from icy planetesimals can unequivocally explain the presence of CO gas in the disk of HD21997.

  6. The California Debris Commission: A History

    Science.gov (United States)

    1981-01-01

    the pipe a more freely in the horizontal plane, while vertical elastic packing in the joint instead of two stable instrument to handle. movement was...report of January duplicate and triplicate taxation , and (4) it 1880 painted a dark and sobering picture Following two months of intense and had not the...isolated cases it is possible to impound debris without injury; also, that loca- tions exist in the canons of the different mining streams in the Sierra

  7. Forewarning of Debris flows using Intelligent Geophones

    Science.gov (United States)

    PK, I.; Ramesh, M. V.

    2017-12-01

    Landslides are one of the major catastrophic disasters that cause significant damage to human life and civil structures. Heavy rainfall on landslide prone areas can lead to most dangerous debris flow, where the materials such as mud, sand, soil, rock, water and air will move with greater velocity down the mountain. This sudden slope instability can lead to loss of human life and infrastructure. According to our knowledge, till now no one could identify the minutest factors that lead to initiation of the landslide. In this work, we aim to study the landslide phenomena deeply, using the landslide laboratory set up in our university. This unique mechanical simulator for landslide initiation is equipped with the capability to generate rainfall, seepage, etc., in the laboratory setup. Using this setup, we aim to study several landslide initiation scenarios generated by varying different parameters. The complete setup will be equipped with heterogeneous sensors such as rain gauge, moisture sensor, pore pressure sensor, strain gauges, tiltmeter, inclinometer, extensometer, and geophones. Our work will focus on the signals received from the intelligent geophone system for identifying the underground vibrations during a debris flow. Using the large amount of signals derived from the laboratory set up, we have performed detailed signal processing and data analysis to determine the fore warning signals captured by these heterogeneous sensors. Detailed study of these heterogeneous signals has provided the insights to forewarning the community based on the signals generated during the laboratory tests. In this work we will describe the details of the design, development, methodology, results, inferences and the suggestion for the next step to detect and forewarn the students. The response of intelligent geophone sensors at the time of failure, failure style and subsequent debris flow for heterogeneous soil layers were studied, thus helping in the development of fore warning

  8. Debris flow-induced topographic changes: effects of recurrent debris flow initiation.

    Science.gov (United States)

    Chen, Chien-Yuan; Wang, Qun

    2017-08-12

    Chushui Creek in Shengmu Village, Nantou County, Taiwan, was analyzed for recurrent debris flow using numerical modeling and geographic information system (GIS) spatial analysis. The two-dimensional water flood and mudflow simulation program FLO-2D were used to simulate debris flow induced by rainfall during typhoon Herb in 1996 and Mindulle in 2004. Changes in topographic characteristics after the debris flows were simulated for the initiation of hydrological characteristics, magnitude, and affected area. Changes in topographic characteristics included those in elevation, slope, aspect, stream power index (SPI), topographic wetness index (TWI), and hypsometric curve integral (HI), all of which were analyzed using GIS spatial analysis. The results show that the SPI and peak discharge in the basin increased after a recurrence of debris flow. The TWI was higher in 2003 than in 2004 and indicated higher potential of landslide initiation when the slope of the basin was steeper. The HI revealed that the basin was in its mature stage and was shifting toward the old stage. Numerical simulation demonstrated that the parameters' mean depth, maximum depth, affected area, mean flow rate, maximum flow rate, and peak flow discharge were increased after recurrent debris flow, and peak discharge occurred quickly.

  9. Controlling the Growth of Future LEO Debris Populations with Active Debris Removal

    Science.gov (United States)

    Liou, J.-C.; Johnson, N. L.; Hill, N. M.

    2008-01-01

    Active debris removal (ADR) was suggested as a potential means to remediate the low Earth orbit (LEO) debris environment as early as the 1980s. The reasons ADR has not become practical are due to its technical difficulties and the high cost associated with the approach. However, as the LEO debris populations continue to increase, ADR may be the only option to preserve the near-Earth environment for future generations. An initial study was completed in 2007 to demonstrate that a simple ADR target selection criterion could be developed to reduce the future debris population growth. The present paper summarizes a comprehensive study based on more realistic simulation scenarios, including fragments generated from the 2007 Fengyun-1C event, mitigation measures, and other target selection options. The simulations were based on the NASA long-term orbital debris projection model, LEGEND. A scenario, where at the end of mission lifetimes, spacecraft and upper stages were moved to 25-year decay orbits, was adopted as the baseline environment for comparison. Different annual removal rates and different ADR target selection criteria were tested, and the resulting 200-year future environment projections were compared with the baseline scenario. Results of this parametric study indicate that (1) an effective removal strategy can be developed based on the mass and collision probability of each object as the selection criterion, and (2) the LEO environment can be stabilized in the next 200 years with an ADR removal rate of five objects per year.

  10. Mitigation of Debris Flow Damage--­ A Case Study of Debris Flow Damage

    Science.gov (United States)

    Lin, J. C.; Jen, C. H.

    Typhoon Toraji caused more than 30 casualties in Central Taiwan on the 31st July 2001. It was the biggest Typhoon since the Chi-Chi earthquake of 1999 with huge amounts of rainfall. Because of the influence of the earthquake, loose debris falls and flows became major hazards in Central Taiwan. Analysis of rainfall data and sites of slope failure show that damage from these natural hazards were enhanced as a result of the Chi-Chi earthquake. Three main types of hazard occurred in Central Taiwan: land- slides, debris flows and gully erosion. Landslides occurred mainly along hill slopes and banks of channels. Many dams and houses were destroyed by flooding. Debris flows occurred during typhoon periods and re-activated ancient debris depositions. Many new gullies were therefore developed from deposits loosened and shaken by the earthquake. This paper demonstrates the geological/geomorphological background of the hazard area, and reviews methods of damage mitigation in central Taiwan. A good example is Hsi-Tou, which had experienced no gully erosion for more than 40 years. The area experienced much gully erosion as a result of the combined effects of earth- quake and typhoon. Although Typhoon Toraji produced only 30% of the rainfall of Typhoon Herb of 1996, it caused more damage in the Hsi-Tou area. The mitigation of debris flow hazards in Hsi-tou area is discussed in this paper.

  11. Plastic debris in the open ocean

    KAUST Repository

    Cozar, Andres

    2014-06-30

    There is a rising concern regarding the accumulation of floating plastic debris in the open ocean. However, the magnitude and the fate of this pollution are still open questions. Using data from the Malaspina 2010 circumnavigation, regional surveys, and previously published reports, we show a worldwide distribution of plastic on the surface of the open ocean, mostly accumulating in the convergence zones of each of the five subtropical gyres with comparable density. However, the global load of plastic on the open ocean surface was estimated to be on the order of tens of thousands of tons, far less than expected. Our observations of the size distribution of floating plastic debris point at important size-selective sinks removing millimeter-sized fragments of floating plastic on a large scale. This sink may involve a combination of fast nano-fragmentation of the microplastic into particles of microns or smaller, their transference to the ocean interior by food webs and ballasting processes, and processes yet to be discovered. Resolving the fate of the missing plastic debris is of fundamental importance to determine the nature and significance of the impacts of plastic pollution in the ocean.

  12. CIRCUMSTELLAR DEBRIS DISKS: DIAGNOSING THE UNSEEN PERTURBER

    Energy Technology Data Exchange (ETDEWEB)

    Nesvold, Erika R. [Department of Terrestrial Magnetism, Carnegie Institution for Science, 5241 Broad Branch Rd., Washington, DC 20015 (United States); Naoz, Smadar; Vican, Laura [Department of Physics and Astronomy, UCLA, 475 Portola Plaza, Los Angeles, CA 90095 (United States); Farr, Will M. [School of Physics and Astronomy, University of Birmingham, Birmingham, B15 2TT (United Kingdom)

    2016-07-20

    The first indication of the presence of a circumstellar debris disk is usually the detection of excess infrared emission from the population of small dust grains orbiting the star. This dust is short-lived, requiring continual replenishment, and indicating that the disk must be excited by an unseen perturber. Previous theoretical studies have demonstrated that an eccentric planet orbiting interior to the disk will stir the larger bodies in the belt and produce dust via interparticle collisions. However, motivated by recent observations, we explore another possible mechanism for heating a debris disk: a stellar-mass perturber orbiting exterior to and inclined to the disk and exciting the disk particles’ eccentricities and inclinations via the Kozai–Lidov mechanism. We explore the consequences of an exterior perturber on the evolution of a debris disk using secular analysis and collisional N -body simulations. We demonstrate that a Kozai–Lidov excited disk can generate a dust disk via collisions and we compare the results of the Kozai–Lidov excited disk with a simulated disk perturbed by an interior eccentric planet. Finally, we propose two observational tests of a dust disk that can distinguish whether the dust was produced by an exterior brown dwarf or stellar companion or an interior eccentric planet.

  13. Plastic debris in the open ocean.

    Science.gov (United States)

    Cózar, Andrés; Echevarría, Fidel; González-Gordillo, J Ignacio; Irigoien, Xabier; Ubeda, Bárbara; Hernández-León, Santiago; Palma, Alvaro T; Navarro, Sandra; García-de-Lomas, Juan; Ruiz, Andrea; Fernández-de-Puelles, María L; Duarte, Carlos M

    2014-07-15

    There is a rising concern regarding the accumulation of floating plastic debris in the open ocean. However, the magnitude and the fate of this pollution are still open questions. Using data from the Malaspina 2010 circumnavigation, regional surveys, and previously published reports, we show a worldwide distribution of plastic on the surface of the open ocean, mostly accumulating in the convergence zones of each of the five subtropical gyres with comparable density. However, the global load of plastic on the open ocean surface was estimated to be on the order of tens of thousands of tons, far less than expected. Our observations of the size distribution of floating plastic debris point at important size-selective sinks removing millimeter-sized fragments of floating plastic on a large scale. This sink may involve a combination of fast nano-fragmentation of the microplastic into particles of microns or smaller, their transference to the ocean interior by food webs and ballasting processes, and processes yet to be discovered. Resolving the fate of the missing plastic debris is of fundamental importance to determine the nature and significance of the impacts of plastic pollution in the ocean.

  14. Bremsstrahlung converter debris shields: test and analysis

    International Nuclear Information System (INIS)

    Reedy, E.D. Jr.; Perry, F.C.

    1983-10-01

    Electron beam accelerators are commonly used to create bremsstrahlung x-rays for effects testing. Typically, the incident electron beam strikes a sandwich of three materials: (1) a conversion foil, (2) an electron scavenger, and (3) a debris shield. Several laboratories, including Sandia National Laboratories, are developing bremsstrahlung x-ray sources with much larger test areas (approx. 200 to 500 cm 2 ) than ever used before. Accordingly, the debris shield will be much larger than before and subject to loads which could cause shield failure. To prepare for this eventuality, a series of tests were run on the Naval Surface Weapons Center's Casino electron beam accelerator (approx. 1 MeV electrons, 100 ns FWHM pulse, 45 kJ beam energy). The primary goal of these tests was to measure the stress pulse which loads a debris shield. These measurements were made with carbon gages mounted on the back of the converter sandwich. At an electron beam fluence of about 1 kJ/cm 2 , the measured peak compressive stress was typically in the 1 to 2 kbar range. Measured peak compressive stress scaled in a roughly linear manner with fluence level as the fluence level was increased to 10 kJ/cm 2 . The duration of the compressive pulse was on the order of microseconds. In addition to the stress wave measurements, a limited number of tests were made to investigate the type of damage generated in several potential shield materials

  15. Plastic debris in the open ocean

    Science.gov (United States)

    Cózar, Andrés; Echevarría, Fidel; González-Gordillo, J. Ignacio; Irigoien, Xabier; Úbeda, Bárbara; Hernández-León, Santiago; Palma, Álvaro T.; Navarro, Sandra; García-de-Lomas, Juan; Ruiz, Andrea; Fernández-de-Puelles, María L.; Duarte, Carlos M.

    2014-01-01

    There is a rising concern regarding the accumulation of floating plastic debris in the open ocean. However, the magnitude and the fate of this pollution are still open questions. Using data from the Malaspina 2010 circumnavigation, regional surveys, and previously published reports, we show a worldwide distribution of plastic on the surface of the open ocean, mostly accumulating in the convergence zones of each of the five subtropical gyres with comparable density. However, the global load of plastic on the open ocean surface was estimated to be on the order of tens of thousands of tons, far less than expected. Our observations of the size distribution of floating plastic debris point at important size-selective sinks removing millimeter-sized fragments of floating plastic on a large scale. This sink may involve a combination of fast nano-fragmentation of the microplastic into particles of microns or smaller, their transference to the ocean interior by food webs and ballasting processes, and processes yet to be discovered. Resolving the fate of the missing plastic debris is of fundamental importance to determine the nature and significance of the impacts of plastic pollution in the ocean. PMID:24982135

  16. Satellite Collision Modeling with Physics-Based Hydrocodes: Debris Generation Predictions of the Iridium-Cosmos Collision Event and Other Impact Events

    International Nuclear Information System (INIS)

    Springer, H.K.; Miller, W.O.; Levatin, J.L.; Pertica, A.J.; Olivier, S.S.

    2010-01-01

    Satellite collision debris poses risks to existing space assets and future space missions. Predictive models of debris generated from these hypervelocity collisions are critical for developing accurate space situational awareness tools and effective mitigation strategies. Hypervelocity collisions involve complex phenomenon that spans several time- and length-scales. We have developed a satellite collision debris modeling approach consisting of a Lagrangian hydrocode enriched with smooth particle hydrodynamics (SPH), advanced material failure models, detailed satellite mesh models, and massively parallel computers. These computational studies enable us to investigate the influence of satellite center-of-mass (CM) overlap and orientation, relative velocity, and material composition on the size, velocity, and material type distributions of collision debris. We have applied our debris modeling capability to the recent Iridium 33-Cosmos 2251 collision event. While the relative velocity was well understood in this event, the degree of satellite CM overlap and orientation was ill-defined. In our simulations, we varied the collision CM overlap and orientation of the satellites from nearly maximum overlap to partial overlap on the outermost extents of the satellites (i.e, solar panels and gravity boom). As expected, we found that with increased satellite overlap, the overall debris cloud mass and momentum (transfer) increases, the average debris size decreases, and the debris velocity increases. The largest predicted debris can also provide insight into which satellite components were further removed from the impact location. A significant fraction of the momentum transfer is imparted to the smallest debris (< 1-5mm, dependent on mesh resolution), especially in large CM overlap simulations. While the inclusion of the smallest debris is critical to enforcing mass and momentum conservation in hydrocode simulations, there seems to be relatively little interest in their

  17. The debris disc of solar analogue τ Ceti: Herschel observations and dynamical simulations of the proposed multiplanet system

    NARCIS (Netherlands)

    Lawler, S.M.; Di Francesco, J.; Kennedy, G.M.; Sibthorpe, B.; Booth, M.; Vandenbussche, B.; Matthews, B.C.; Holland, W.S.; Greaves, J.; Wilner, D.J.; Tuomi, M.; Blommaert, J.A.D.L.; de Vries, B.L.; Dominik, C.; Fridlund, M.; Gear, W.; Heras, A.M.; Ivison, R.; Olofsson, G.

    2014-01-01

    τ Ceti is a nearby, mature G-type star very similar to our Sun, with a massive Kuiper Belt analogue and possible multiplanet system that has been compared to our Solar system. We present Herschel Space Observatory images of the debris disc, finding the disc is resolved at 70 μm and 160 μm, and

  18. Treatment technology analysis for mixed waste containers and debris

    International Nuclear Information System (INIS)

    Gehrke, R.J.; Brown, C.H.; Langton, C.A.; Askew, N.M.; Kan, T.; Schwinkendorf, W.E.

    1994-03-01

    A team was assembled to develop technology needs and strategies for treatment of mixed waste debris and empty containers in the Department of Energy (DOE) complex, and to determine the advantages and disadvantages of applying the Debris and Empty Container Rules to these wastes. These rules issued by the Environmental Protection Agency (EPA) apply only to the hazardous component of mixed debris. Hazardous debris that is subjected to regulations under the Atomic Energy Act because of its radioactivity (i.e., mixed debris) is also subject to the debris treatment standards. The issue of treating debris per the Resource Conservation and Recovery Act (RCRA) at the same time or in conjunction with decontamination of the radioactive contamination was also addressed. Resolution of this issue requires policy development by DOE Headquarters of de minimis concentrations for radioactivity and release of material to Subtitle D landfills or into the commercial sector. The task team recommends that, since alternate treatment technologies (for the hazardous component) are Best Demonstrated Available Technology (BDAT): (1) funding should focus on demonstration, testing, and evaluation of BDAT on mixed debris, (2) funding should also consider verification of alternative treatments for the decontamination of radioactive debris, and (3) DOE should establish criteria for the recycle/reuse or disposal of treated and decontaminated mixed debris as municipal waste

  19. Debris flows associated with the 2015 Gorkha Earthquake in Nepal

    Science.gov (United States)

    Dahlquist, M. P.; West, A. J.; Martinez, J.

    2017-12-01

    Debris flows are a primary driver of erosion and a major geologic hazard in many steep landscapes, particularly near the headwaters of rivers, and are generated in large numbers by extreme events. The 2015 Mw 7.8 Gorkha Earthquake triggered 25,000 coseismic landslides in central Nepal. During the ensuing monsoon, sediment delivered to channels by landslides was mobilized in the heavy rains, and new postseismic landslides were triggered in rock weakened by the shaking. These coseismic and postseismic landslide-generated debris flows form a useful dataset for studying the impact and behavior of debris flows on one of the most active landscapes on Earth. Debris flow-dominated channel reaches are generally understood to have a topographic signature recognizable in slope-area plots and distinct from fluvial channels, but in examining debris flows associated with the Gorkha earthquake we find they frequently extend into reaches with geometry typically associated with fluvial systems. We examine a dataset of these debris flows, considering whether they are generated by coseismic or postseismic landslides, whether they are likely to be driving active incision into bedrock, and whether their channels correspond with those typically associated with debris flows. Preliminary analysis of debris flow channels in Nepal suggests there may be systematic differences in the geometry of channels containing debris flows triggered by coseismic versus postseismic landslides, which potentially holds implications for hazard analyses and the mechanics behind the different debris flow types.

  20. The effect of debris-flow composition on runout distance

    Science.gov (United States)

    de Haas, Tjalling; Braat, Lisanne; Leuven, Jasper; Lokhorst, Ivar; Kleinhans, Maarten

    2015-04-01

    Estimating runout distance is of major importance for the assessment and mitigation of debris-flow hazards. Debris-flow runout distance depends on debris-flow composition and topography, but state-of-the-art runout prediction methods are mainly based on topographical parameters and debris-flow volume, while composition is generally neglected or incorporated in empirical constants. Here we experimentally investigated the effect of debris-flow composition and topography on runout distance. We created the first small-scale experimental debris flows with self-formed levees, distinct lobes and morphology and texture accurately resembling natural debris flows. In general, the effect of debris-flow composition on runout distance was larger than the effect of topography. Enhancing channel slope and width, outflow plain slope, debris-flow size and water fraction leads to an increase in runout distance. However, runout distance shows an optimum relation with coarse-material and clay fraction. An increase in coarse-material fraction leads to larger runout distances by increased grain collisional forces and more effective levee formation, but too much coarse debris causes a large accumulation of coarse debris at the flow front, enhancing friction and decreasing runout. An increase in clay fraction initially enlarges the volume and viscosity of the interstitial fluid, liquefying the flow and enhancing runout, while a further increase leads to very viscous flows with high yield strength, reducing runout. These results highlight the importance and further need of research on the relation between debris-flow composition and runout distance. Our experiments further provide valuable insight on the effects of debris-flow composition on depositional mechanisms and deposit morphology.