Dissertations / Theses on the topic 'Space debris'
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Baker, Howard A. "Space debris : legal and policy implications." Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61730.
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Früh, Carolin [Verfasser]. "Identification of Space Debris / Carolin Früh." Aachen : Shaker, 2011. http://d-nb.info/1070150770/34.
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Fortin, Pierre 1960. "Artificial space debris and international law." Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59927.
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In just three decades of human exploration and utilization of outer space, an unwanted legacy of thousands of artificial space debris has been left behind.The purpose of this thesis is to analyse the appropriate technical aspects of the artificial space debris issue and to explore the legal ramifications of the question.
The first chapter is devoted to the technical aspects and covers topics such as the origins and location of artificial space debris, the hazards they constitute, the anticipated damage that might be caused by such debris and the likelihood of its occurrence.
In the second chapter, the legal aspects are explored by first looking at space law generally. A brief historical perspective of space law as well as the role of the United Nations in the making of space law is offered. Space law as it relates to the space debris issue is then analysed by first trying to define terms such as "space object", "component parts" and "space debris". Particular emphasis is then placed on issues like jurisdiction and control over space debris, international responsibility for space debris, their identification and, finally, liability for damage caused by space debris.
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Barrows, Simon. "Evolution of artificial space debris clouds." Thesis, University of Southampton, 1996. https://eprints.soton.ac.uk/192401/.
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Over 120 cases of on-orbit breakups have now been recorded. Many more undetected events are believed to have occurred. Each time an object breaks up, whether by explosion or collision, a cloud of debris is formed. The overall objective of the PhD is to examine the interaction between the debris clouds produced by on-orbit fragmentation events and specific space systems. A breakup event will give rise to concentrations of debris which, for some time after the event, will have spatial densities considerably higher than the background flux. Thus, a detailed knowledge of the extent to which the cloud will grow over a given time period, and an accurate assessment of the risk of collision for a spacecraft passing through it, may prove to be important in mission planning and satellite shielding design. The SDS (Space Debris Simulation) software suite has been developed to carry out the analysis presented in this thesis and now represents the state-of-theart in debris cloud modelling. The integrated structure of the developed software enables a wide variety of analyses to be conducted and simulations of both historic and potential future orbital fragmentation events to be performed. Program BREAKUP uses a combination of empirical and analytical models to simulate catastrophic and non-catastrophic collisions, and also variable intensity explosive fragmentations. Included in BREAKUP is a novel parametric model for producing and controlling non-isotropic fragment spreads. TRAJECTORY acts as a test-bed for orbit propagation techniques, providing the facility for convenient and direct method comparison. EVOLUTION enables the complex dynamics of debris cloud growth to be visualised and in particular the effects of propagation method to be examined. Program TARGET employs a novel implementation of the method of probabilistic continuum dynamics to perform collision hazard assessments for spacecraft which encounter debris clouds. Among the additional new developments included in TARGET are the consideration of atmospheric drag, a direct interface with a non-isotropic cloud model, the use of a cellular target spacecraft representation and impact energy-related damage assessment algorithm, and a built-in satellite constellation analysis facility. A number of case studies are presented to illustrate the modelling capabilities of the SDS software suite, including the simulation of several historic fragmentation events and the debris cloud collision risks to ENVISAT-1 and the Iridium™ satellite constellation. The results produced by the models are validated by comparisons with other simulation software and, wherever possible, with actual breakup event, debris impact and spacecraft, orbit, data.
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Bischof, Roberta Joan. "The international policy implications of debris in outer space." Thesis, Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/28656.
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Hürl, Kay-Uwe. "Legal and technical considerations of space debris." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33358.
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This thesis deals with the technical and legal measures presently available to combat space debris. Space debris is not as far out as it sounds. The issue is real and may become severe if no action is taken.Focusing on existing legal instruments, this study shows their inadequacy in addressing space debris. As space debris was not considered an actual or a legal problem at the time of drafting, the provisions of international space law fail to provide solutions in certain areas.
Recommendations for the future are made. Considering the increase in outer space activities, solutions for the space debris threat are a necessity. Developing technology will only solve some of the problems as the amount of space debris proliferates in collisions of existing debris. Therefore, legal challenges will also be faced, some of which are discussed herein.
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Taylor, Michael W. 1971. "Orbital debris : technical and legal issues and solutions." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99558.
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This thesis examines the current technological and legal issues concerning orbital debris (space debris). The unique physical characteristics of the space environment are identified and explained. The thesis then explores the causes of orbital debris and examines the risk posed by debris to the most frequently used orbital areas. Significant environmental, legal, political, and economic consequences of orbital debris are described. The current technical and legal controls on the creation of debris are discussed and evaluated. Finally, proposed solutions are considered and critiqued. The thesis concludes with a non-binding treaty-based proposal for a new legal debris control regime that can encourage compliance and enhance accountability.
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Oswald, Michael. "New contributions to space debris environment modeling." Aachen Shaker, 2008. http://d-nb.info/988549123/04.
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McNutt, Ross Theodore. "Orbiting space debris : dangers, measurement and mitigation." Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/43246.
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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1992.Title as it appears in the M.I.T. Graduate List, Feb. 1992: Orbital space debris, dangers, measurement and mitigation.
Includes bibliographical references (leaves 321-331).
by Ross Theodore McNutt.
M.S.
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Vasilieva, Stephania. "Ontologies as Bayesian Networks for Space Debris." Thesis, The University of Arizona, 2016. http://hdl.handle.net/10150/613564.
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Space debris is a rising problem in today's world. Because there is so much in space that is unknown, it is critical to eventually catalog every piece. Since there are many attributes and properties attached to space objects, it is preferable to use an ontological classification method. The information presented in the ontology can then be used to answer questions about space debris. A Bayesian network would accomplish that because of its quantitative nature. The similarities between ontologies and Bayesian networks, such as their architectures and their flexibility, make it possible to integrate an ontology into a Bayesian network. Image determination and object collision assessment were used as applications to check the viability of integrating ontologies and Bayesian networks. It was determined that ontologies and Bayesian networks are tools that when combined can result in new useful quantitative information.
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Hedengren, Gustav, and Oscar Larsson. "Electrostatic ion thrusters for space debris removal." Thesis, KTH, Skolan för teknikvetenskap (SCI), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-230750.
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The current levels of space debris are critical and actions are needed to preventcollisions. In this paper it is examined whether an electrostatic ion thruster canbe powerful enough to slow down the debris in a sufficient manner. Furthermore,it is looked into whether the process can be repeated for a significant numberof pieces by maneuvering between them. We conclude that the removal processseems possible although some improvements are needed. Maneuvering is costlybut despite conservative assumptions, we estimate that about 800 pieces can beremoved in one journey made by a satellite weighing ten tonnes of which nine arexenon.Den nuvarande nivån av rymdskrot är kritisk och åtgärder krävs för att förhindra kollisioner. I denna artikel undersöks det huruvida en elektrostatisk jonkanon är kraftfull nog för att bromsa skrot tillräckligt. Fortsättningsvis undersöks det om denna process är effectiv nog för att återupprepas för ett betydande antal bitar, inklusive manövrering bitarna emellan. Vi drar slutsatsen att processen verkar möjlig att genomföra även om vissa förbättringar behövs. Manövreringen är kostsam men trots konservativa antaganden uppskattar vi att ungefär 800 bitar kan tas ned under en resa av en satellit med vikt 10 ton varav nio ton är xenon.
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Ortiz, Gomez Natalia. "Eddy currents applied to space debris objects." Thesis, University of Southampton, 2017. https://eprints.soton.ac.uk/415734/.
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The increasing population of space debris in the near-Earth region poses a serious threat to operational satellites in-orbit. This situation has led to the development of numerous guidelines in order to mitigate the potential danger of in-orbit collisions, fragmentations and uncontrolled re-entries. Among the various recommendations, active debris removal is considered as a possible solution to help decrease the chance of the aforementioned risks. However, active debris removal has never been done in space and it still requires further development of various technologies and orbit testing before it can become a reality. One of the major challenges to overcome is how to capture rotating space debris objects. Some of these objects may have high rotational speeds which hampers their capture and subsequent controlled re-entry. This research focuses on the analysis of the eddy current phenomenon on space debris objects by the Earth magnetic field as well as its practical application to develop a de-tumbling method for active debris removal based on the generation of eddy currents. The first part of the project focuses on the development of a new mathematical approach which generalises the existing analytical models and simplifies the numerical methods typically employed to analyse the eddy current phenomenon. This mathematical approach, referred to as the magnetic tensor theory, is validated both numerically and experimentally. The theory is based on the discovery of a symmetric Cartesian tensor of second order with no negative eigenvalues, named the magnetic tensor. A method to evaluate this tensor based on a generic finite element method is provided as well as a particularization for a specific F.E.M. which leads to a direct formula to evaluate this tensor. This way, the eddy current torque solution may be found without the necessity to solve the classical Poisson equation with Neumann boundary conditions in each time step of the integration process of Euler’s equation. This breakthrough greatly reduces the complexity and computational time of the classical approach commonly adopted in the past. The second part of the project focuses on the design of a contactless de-tumbling method based on the generation of eddy currents named the eddy brake method. This design delves deeper into the idea first suggested by Kadaba and Naishadham in 1995 which consists in subjecting a space debris object to an enhanced magnetic field in order to damp its rotation. The advances in high temperature superconducting materials as well as spacecraft sensors and actuators has allowed for a compelling new design to be reached within this research which may serve as a stepping stone for future ADR missions. A thorough systems engineering design of the eddy brake is presented with special attention to the thermal and guidance, navigation and control subsystems. These subsystems have been identified as the two most relevant ones to support the operation of the eddy brake. The results show that the eddy brake is a promising solution to reduce the rotation of metallic space debris and allow for their subsequent capture.
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Tam, Walter. "The Space Debris Environment and Satellite Manufacturing." ScholarWorks, 2015. https://scholarworks.waldenu.edu/dissertations/1660.
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Space debris is a growing threat to operational satellites and satellite manufacturing organizations. Leaders in satellite manufacturing organizations lacking adequate knowledge on the space debris risks could be at a competitive disadvantage. The purpose of this explorative case study was to explore strategies leaders in satellite manufacturing organizations use to mitigate risks through the conceptual lens of stakeholder theory, contingency theory, and general system theory. The research questions addressed strategies to mitigate the debris threat from the perspectives of both ongoing concerns and long-term risk resolution. Data were collected via in-depth interviews with 12 leaders, purposively selected, in satellite manufacturing organizations, and supplemented with documentation from the literature and archival records from NASA. Member checking was used to validate the transcribed data subsequently coded into 6 themes that included: meeting requirements; using analytical techniques; using shielding to protect satellites; implementing material and process innovation; developing satellite services; and generating end of mission requirements. Recommendations include maintaining and developing analytical competencies, funding research and development, and establishing standardization. Using strategies that facilitate risk mitigation and the preservation of the space environment, business leaders could benefit by developing strategic road maps that ensure continued access to space. Implications for social change include contributing to social stability, technology advancement, increased knowledge base, economic growth, higher education, and improved standard of living.
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Schmitz, Manuel [Verfasser]. "Active Removal of Space Debris with Space-Based Lasers / Manuel Schmitz." München : Verlag Dr. Hut, 2016. http://d-nb.info/1117982459/34.
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McCall, Paul D. "Modeling, Simulation, and Characterization of Space Debris in low-Earth Orbit." FIU Digital Commons, 2013. http://digitalcommons.fiu.edu/etd/965.
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Every space launch increases the overall amount of space debris. Satellites have limited awareness of nearby objects that might pose a collision hazard. Astrometric, radiometric, and thermal models for the study of space debris in low-Earth orbit have been developed. This modeled approach proposes analysis methods that provide increased Local Area Awareness for satellites in low-Earth and geostationary orbit. Local Area Awareness is defined as the ability to detect, characterize, and extract useful information regarding resident space objects as they move through the space environment surrounding a spacecraft.
The study of space debris is of critical importance to all space-faring nations. Characterization efforts are proposed using long-wave infrared sensors for space-based observations of debris objects in low-Earth orbit. Long-wave infrared sensors are commercially available and do not require solar illumination to be observed, as their received signal is temperature dependent. The characterization of debris objects through means of passive imaging techniques allows for further studies into the origination, specifications, and future trajectory of debris objects. Conclusions are made regarding the aforementioned thermal analysis as a function of debris orbit, geometry, orientation with respect to time, and material properties. Development of a thermal model permits the characterization of debris objects based upon their received long-wave infrared signals. Information regarding the material type, size, and tumble-rate of the observed debris objects are extracted. This investigation proposes the utilization of long-wave infrared radiometric models of typical debris to develop techniques for the detection and characterization of debris objects via signal analysis of unresolved imagery.
Knowledge regarding the orbital type and semi-major axis of the observed debris object are extracted via astrometric analysis. This knowledge may aid in the constraint of the admissible region for the initial orbit determination process. The resultant orbital information is then fused with the radiometric characterization analysis enabling further characterization efforts of the observed debris object. This fused analysis, yielding orbital, material, and thermal properties, significantly increases a satellite’s Local Area Awareness via an intimate understanding of the debris environment surrounding the spacecraft.
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Lidtke, Aleksander A. "High collision probability conjunctions and space debris remediation." Thesis, University of Southampton, 2016. https://eprints.soton.ac.uk/413808/.
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Derelict satellites, rocket bodies, and pieces thereof have been left on orbit. These space debris have been increasing in numbers and simulations of their future evolution have shown that this increase might continue due to collisions between objects. It has been suggested that active debris removal (ADR), i.e. removing objects from orbit by technological means rather than by their natural decay due to drag, might be necessary in order to prevent an excessive increase of the number of debris. Selection of objects to be targeted by ADR is considered important because removal of non-relevant objects will unnecessarily increase the cost of ADR. Collision probability of every object should form part of the metric to select appropriate ADR targets. This work examines how the collision probabilities of all the objects in orbit depend on particular conjunctions, which cannot be forecast far in advance due to increasing orbit propagation uncertainty and variations in solar activity. It is found that conjunctions with high collision probabilities contribute more to the collision probabilities accumulated by objects over a period of time than other close approaches. Objects that are not large in mass and size are found to take part in conjunctions with high collision probabilities. Such objects are not likely to be removed from orbit when using existing ADR target selection schemes, and collisions involving them might not be prevented. Thus, the growth of the number of debris might continue in spite of ADR because collision fragments will continue to be generated. A complementary solution to constraining the number of debris in orbit, i.e. prevention of collisions between derelicts (just in-time collision avoidance, JCA), is thus investigated. It is found that fewer than ten JCA actions per year could constrain the number of objects in orbit. However, certain objects will repetitively take part in conjunctions with high collision probabilities. Permanently removing such objects from orbit via ADR may be more cost-effective than mitigating their collision risk via JCA. The finding that conjunctions with relatively high collision probabilities are the reason why ADR may be insufficient to constrain the number of debris, and analysis of JCA using an evolutionary debris model are the main novel contributions of this work.
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Letizia, Francesca. "Space debris cloud evolution in Low Earth Orbit." Thesis, University of Southampton, 2016. https://eprints.soton.ac.uk/387121/.
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The Earth is surrounded by inoperative objects generated from past and current space missions. Because of the high orbital speed, even the impact with small fragments is a hazard to operational spacecraft as it could lead to the partial or complete loss of the mission. Therefore, it is important to assess the collision risk due to space debris considering small fragments, which are usually not included in space debris modelling because their large number would make simulations extremely complex. In this work, an analytical approach is developed to describe the evolution of debris clouds created by fragmentations in Low Earth Orbit. In contrast to traditional approaches, which follow the trajectory of individual fragments, with the proposed method the cloud behaviour is studied globally, so that the presence of small fragments can be modelled. This give a deeper insight into the dynamics of debris clouds and reduces the computational effort needed to estimate the consequences of a collision. A standard breakup model is used to describe the dispersion of the fragments in terms of characteristic length, area-to mass ratio and velocity. From the velocity distribution, the fragment spatial dispersion is derived. The cloud density is expressed by a continuous function that depends on the altitude and that is set as initial condition for the orbit propagation. Based on an analytical approach proposed in the literature for interplanetary dust and spacecraft swarms, the fragment cloud evolution in time is derived through the continuity equation, which is used to describe the variation of debris density considering the effect of atmospheric drag. The approach has been extended to express the cloud density as a function of multiple orbital parameters and to model additional perturbations such as the Earth’s oblateness. The method has been validated through the comparison with the traditional numerical propagation and then applied to study many breakup scenarios. The proposed approach proves to be flexible and able to study the collision risk coming from several breakup events and to evaluate the vulnerability of different targets. It is also applied to derive an index of the environmental criticality of spacecraft.
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MUNTONI, GIACOMO. "Space Debris Observations with the Sardinia Radio Telescope." Doctoral thesis, Università degli Studi di Cagliari, 2019. http://hdl.handle.net/11584/260392.
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Space debris are manmade objects orbiting around Earth that represent a growing problem for on-going and future space operations. In order to avoid possible collisions between debris and spacecraft and to monitor the objects during the re-entry process, gathering as much information as possible about them is a primary need. These information can be acquired by means of radar or optical measurements depending on the observing scenario.
Among the worldwide radio telescopes, the Sardinia Radio Telescope (SRT) is a new comer in the space debris detection plan. Although it has been used for several years to acquire and analyze distant radio astronomical sources, only recently it has been tested for space debris detection purposes. For this reason the research group of the Department of Electrical and Electronic Engineering of the University of Cagliari, in collaboration with the Cagliari Astronomical Observatory (OAC), has studied a set of upgrades for the L-P band receiver of the SRT, in order to make the antenna a suitable instrument within the European space debris detection plan.
This doctoral dissertation focuses on the characterization and upgrade of the receiving system and on the test of the whole receiving chain before and after the upgrade.
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Gittins, Gavin Lee. "The interaction between space tether systems and the orbital space debris environment." Thesis, University of Southampton, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.416055.
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Chatterjee, Joyeeta. "Legal aspects of space debris remediation: active removal of debris and on-orbit satellite servicing." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=119752.
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With the alarming proliferation in the population of orbital debris, scientific analysis has indicated a need to perform space debris remediation through active removal of debris and on-orbit satellite servicing. This thesis aims to study the implications of the existing framework of international space law and public international law on space debris remediation. Following a description of the hypothesis and the research methodology, the introductory chapter explains the current state of the debris environment and the consequent need to perform space debris remediation. With that understanding, the economic and technological feasibility for such an endeavour is also assessed. The second chapter addresses the concerns regarding the current definition of a 'space object' and examines the requirement for the adoption of a separate legal definition of space debris to facilitate space debris remediation activities. The key question of legitimate exercise of jurisdiction and control over space objects, in the realm of space debris remediation, along with contentious issues such as transfer of ownership and/or registry of space objects are discussed in the third chapter. The fourth chapter elaborates on the related responsibility and liability considerations linked to remediation activities in outer space. The final chapter contains a summary of the important conclusions from the earlier chapters and presents some overall observations on the entire analysis.Avec la prolifération alarmante du nombre de débris orbitaux, des études scientifiques ont montré la nécessité d'effectuer un nettoyage des débris spatiaux, par le biais de la suppression effective de ces débris ainsi que la mise en place d'un système orbital de « service » aux satellites. Cette thèse vise à étudier les effets du cadre actuel du droit spatial international et du droit international public, sur la gestion du problème des débris spatiaux. Après une description du postulat et de la méthodologie de recherche, le chapitre introductif (chapitre I) explique l'état actuel de l'environnement des débris spatiaux et la nécessité d'éliminer ces débris. Dans ce contexte, la faisabilité économique et technique d'une telle entreprise est évaluée au chapitre II. Le chapitre III traite des questions liées à la définition actuelle d'«objet spatial» et examine les conditions de l'adoption d'une définition juridique distincte pour les débris spatiaux, afin de faciliter les activités de nettoyage afférentes. La question essentielle de l'exercice légitime de la juridiction et du contrôle des objets spatiaux, s'agissant de leur nettoyage, ainsi que les sujets controversés tels que le transfert de propriété et/ou l'enregistrement des objets spatiaux, sont examinés dans le chapitre IV. Le chapitre V entre dans le détail des réflexions sur la responsabilité liée aux activités de dépollution dans l'espace. La section finale (chapitre VI) comprend un résumé des conclusions importantes des chapitres précédents, et présente quelques observations générales sur toute l'analyse.
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Oswald, Michael [Verfasser]. "New Contributions to Space Debris Environment Modeling / Michael Oswald." Aachen : Shaker, 2008. http://d-nb.info/1162790970/34.
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Marchant, Jonathan. "A study on ground-based optical space debris detection." Thesis, University of Kent, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300773.
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Tsikis, Théo. "Innovative Solutions for Satellite Conformity to Space Debris Mitigation." Thesis, KTH, Farkost och flyg, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-195607.
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This thesis presents the work I have accomplished during my 6 months internship in Altran Research more precisely inthe Space Innovation Unit in Cannes, France. This period as trainee was also the conclusion of the double degree program I followed in Aerospace Engineering at KTH, the Royal Institute of Technology of Stockholm, Sweden. This report details every Space Safety related projects in which I have been involved. Every topic is related to the management of low earth orbit satellites disintegration during their atmospheric re-entry. Nowadays orbital pollution has pushed national space agencies to take the lead on space debris mitigation. There are currently more than twenty thousand objects of more than 10 cm constantly tracked from ground to avoid collision within-progress missions. This is implying expensive avoidance manoeuvres thus equipment and budget associated. Items shorter than 10 cm are even more numerous and they cannot be seen from ground so they are estimate by models. The debris population is threatening future missions and even launches if nothing is done to prevent/reduce the debrisformation. To avoid this catastrophic scenario, space agencies have developed and financed projects to prevent and reduce debris creation. In the meantime, risk on ground must be reduced to limit population injuries from falling object. Now satellites are designed/retro-designed to demise more, and in known ways, during uncontrolled re-entry. Software are also currently developed to simulate more precisely the complex aerothermal phenomenon of ablation duringatmospheric re-entry.Detta examensarbete presenterar mitt arbete under en sex månader lång praktik på Altran Research och deras SpaceInnovation Unit i Cannes, Frankrike. Rapporten beskriver de rymdsäkerhetsprojekt jag arbetade med, alla relaterade tillutformning av satelliter i låg jordbana för effektivare sönderfall vid deras atmosfärsåterinträde. Nedskräpning av jordbanor har tvingat nationella rymdstyrelser att ta initiativ för att lindra rymdskrotsproblematiken. Idag spåras banorna för fler än tjugo tusen objekt med en storlek större än 10 cm för att förhindra kollisioner med aktiva satelliter. Detta betyder att dyra undanmanövrar måste göras, vilket påverkar satelliternas utrustning och rymduppdragens budget. Objekt mindre än 10 cm är ännu fler till antalet och de kan inte spåras från jorden. Istället används modeller för att uppskatta deras antal. Rymdskrotspopulationen hotar framtida rymduppdrag och uppskjutningar om ingenting görs för att förhindra eller reducera tillväxen av rymdskrot. För att undvika detta katastrofscenario så har rymdstyrelser utvecklat och finansierat projekt för att förhindra och reducera att nytt rymdskrot skapas. Samtidigt måste risken för att rymdskrot faller ned på marken reduceras för att begränsa skador på människor och egendom. Nuförtiden utformas satelliter för att falla isär och helt och hållet förbrännas vid ett okontrollerat återinträde i atmosfären. Mjukvaror håller på att utvecklas för att mer precist kunna simulera komplex aerotermiska processer och ablationen av material vid atmosfäriskt återinträde.
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White, Adam Edward. "An adaptive strategy to control the space debris population." Thesis, University of Southampton, 2014. https://eprints.soton.ac.uk/377012/.
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As a result of the last 60 years of satellite launches, a significant amount of space debris has been generated in Earth orbit. Growing consensus amongst experts over the last decade, has suggested that removing existing debris, alongside mitigation efforts, can assist in controlling the size of the low Earth orbit (LEO) population. However, no objective or long-term strategy exist to ensure the most effective use of active debris removal (ADR). The way we utilise near-Earth space, and the way the space environment will behave in the future will directly affect the number of debris objects required to be removed. This then, makes it difficult to identify any potential future ADR strategy that will perform effectively in all possible future cases. This thesis explores a novel adaptive strategy that determines how many debris objects should be removed to control the size of the LEO debris population. The strategy adapts and adjusts the number of removals performed by ADR in response to the evolution of the debris population. The framework for the strategy was inspired by the methods incorporated in adaptive management and control engineering. The University of Southampton’s Debris Analysis and Monitoring Architecture to the Geosynchronous Environment (DAMAGE) model was used to represent the space environment, whilst a new debris model entitled the Computational Adaptive Strategy to Control Accurately the Debris Environment (CASCADE) was used to predict the evolution of DAMAGE, and required removal rate. Predictions using DAMAGE were run under a variety of launch, explosion, mitigation and solar activity for both the ≥10 cm and ≥5 cm LEO populations. Two key parameters of the adaptive strategy were also investigated: modifying the frequency of implementation and exploring different high-level objeives for the strategy. Using the adaptive strategy increased the probability of achieving its objective and required fewer removals, as each prediction had a bespoke number of removals. On average, 3.1 removals (standard deviation: 1.2) were required to provide an 88% probability in preventing the growth of the ≥10 cm LEO population. Whereas, implementing realistic variations in launch, explosion, mitigation and solar activity, on average, 6.3 removals (standard deviation: 6.8) were required to prevent the growth of the ≥5 cm LEO population with 76% confidence. This compared with a “traditional” strategy of removing five objects per year that only provided 49% confidence. This approach then, represents a rational method to calculate the number of removals required to ensure the future sustainability of outer space activities.
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Krag, Holger. "A method for the validation of space debris models and for the analysis and planning of radar and optical surveys /." Aachen : Shaker, 2003. http://www.gbv.de/dms/bs/toc/374864071.pdf.
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Paley, M. T. "The development of an automated optical scanning system and studies of the Earth orbital dust environment by means of the LDEF Micro Abrasion Package." Thesis, University of Kent, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282485.
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Flodin, Linus. "Attitude and Orbit Control During Deorbit of Tethered Space Debris." Thesis, KTH, Farkost och flyg, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-166824.
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Due to the unsustainable space debris environment in Low Earth Orbit, debris objects must be removed to ensure future safe satellite operations. One proposed concept for deorbiting larger space debris objects, such as decommissioned satellites or spent upper rocket stages, is to use a chaser spacecraft connected to the debris object by an elastic tether, but the required technology is immature and there is a lack of flight experience. The inoperable satellite, Envisat, has been chosen as a representative object for controlled re-entry by performing several high thrust burns. The aim of this paper is to develop a control system for the deorbit phase of such a mission. Models of the spacecraft dynamics, the tether, and sensors are developed to create a simulator. Two different tether models are considered: the massless model and the lumped mass model. A switched linear-quadratic-Gaussian (LQG) controller is designed to control the relative position of the debris object, and a switched proportional-integral-derivative (PID) controller is designed for attitude control. Feedforward compensation is used to counteract the couplings between relative position and attitude dynamics. An analysis of the system suggests that the tether should be designed in regard to the control system and it is found that the lumped mass model comes with higher cost than reward compared to the massless tether model in this case. Simulations show that the control system is able to control the system under the influence of modeling errors during a multi-burn deorbit strategy and even though more extensive models are suggested to enable assessment of the feasibility to perform this mission in reality, this study has resulted in extensive knowledge and valuable progress in the technical development.En ökande mängd rymdskrot har lett till en ohållbar miljö i låga omloppsbanor och föremål måste nu tas bort för att säkerställa framtida satellitverksamhet. En föreslagen metod för att avlägsna större skrotföremål, såsom avvecklade satelliter och använda övre raketsteg, är att koppla en jagande rymdfarkost till föremålet med en elastisk lina. Dock är den teknik som behövs inte mogen och det finns en brist på praktisk erfarenhet. Den obrukbara satelliten Envisat har valts som representativt objekt för kontrollerat återinträde genom flera perigeumsänkande raketmanövrar. Syftet med detta arbete är att utveckla ett system för att kontrollera de två sammankopplade rymdfarkosterna under avlägsningsfasen under ett sådant uppdrag. Modeller för farkosternas dynamik, den sammankopplande linan och sensorer byggs för att utveckla en simulator. Två olika modeller för linan undersöks: den masslösa modellen och den klumpade nodmassmodellen. En omkopplande regulator designas genom minimering av kvadratiska kriterier för att kontrollera skrotföremålets relativa position till den jagande farkosten. Vidare designas en omkopplande proportionerlig-integrerande-deriverande (PID) regulator för att reglera pekningen hos den jagande farkosten. Kompensering genom framkoppling används för att motverka de korskopplingar som förekommer mellan translations- och rotationsdynamiken. En analys av systemet visar att linan bör designas med reglersystemet i åtanke och det framkommer att nackdelarna överväger fördelarna för den klumpade nodmassmodellen jämfört med den masslösa modellen. Simuleringar visar att reglersystemet klarar att kontrollera systemet under ett scenario med flera manövrar och under inverkan av modellfel. Även om mer omfattande modeller föreslås för att möjliggöra en fullständig bedömning av genomförbarheten för detta uppdrag så har denna studie resulterat i en omfattande kunskapsvinst och värdefulla framgångar i det tekniska utvecklingsarbetet.
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Korsfeldt, Larsén Alexander. "Non-linear Model Predictive Control for space debris removal missions." Thesis, Luleå tekniska universitet, Rymdteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-72049.
Full textAbstract:
The rapidly increasing amounts of space debris orbiting Earth is threatening to reach a critical level, where the near-Earth environment becomes so overfilled with junk that many missions simply become unfeasible. Long-term active debris removal operations appear to be a necessity, but due to the scale of the problem this will likely be an expensive affair spanning decades or even centuries. Many of the mission-related costs can be significantly reduced by making use of a smaller spacecraft, such as the rapidly developing CubeSat standard. An issue with this approach is the limited actuation capabilities, as that makes it very difficult to perform orbital maneuvers in a fuel-efficient manner. Rather than making a few high-impulse thrusts over the course of the mission, the thrust must be applied continuously for several hundred hours. This thesis attempts to solve the problem by using a non-linear Model Predictive Control strategy to implement an Orbital and Attitude Control system for a small satellite. This was done in MATLAB, using the fast-NMPC package MATMPC recently developed by Yutao Chen at Padova University. The controller was tested in a realistic model of the near-Earth environment, where disturbances such as drag and gravitational perturbations are simulated. It was shown through simulations that this method can successfully be used to perform a fuel-efficient rendezvous maneuver with an uncontrollable object, a critical step in any Active Debris Removal operation. Using a 4 kg CubeSat with a 30 µN thruster mounted on each of its six surfaces, the total mass consumption for a phasing maneuver of 10 degrees at 300 km altitude was less than 0.1% of the spacecraft mass. This assumes an Isp of 1,150 s, which is the specific impulse of the S-iEPS Electrostatic thruster flown on the Aero-Cube-8 IMPACT mission. This is made possible through prediction horizons spanning several days, which in turn forces the controller to operate at sampling rates as low as 1/100 Hz due to the computational load. Fully realizing the potential of this technique would likely require the inclusion of a low-level controller that uses the generated trajectories as input values, as this would negate many of the issues associated with a heavy computational load. The urgency of the space debris problem, and the endless list of other CubeSat applications that would benefit from a flexible and fuel-efficient AOCS, makes this an interesting to topic to consider for further research.
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Virdee, Hira Singh. "Radiation pressure torque and computational attitude modelling of space debris." Thesis, University College London (University of London), 2017. http://discovery.ucl.ac.uk/1571169/.
Full textAbstract:
Human space activity in the past 50 years has led to a plethora of man-made space debris which pose an imminent threat to global space operations. The current models of space debris orbits are not sufficient for detailed orbit prediction or for accurate tracking. This uncertainty manifests itself in Conjunction Analysis (CA) with active spacecraft, which leads to excessive orbital manoeuvres which are both expensive and reduce the lifetime of satellites. Advances in orbit modelling will lead to better prediction of debris orbits and reduce the need for collision avoidance manoeuvres, as well as minimising the future pollution of the space environment through collisions. Most existing methods for analysing the orbits of space debris do not take into account the effects of tumbling, and the attitude-dependent nonconservative forces are generally neglected. This study models the torques and attitude motion of uncontrolled man-made objects in orbit about the Earth, which tumble due to a combination of natural influences of the near-Earth space environment and initial angular momentum acquired during debris formation. The modelling of space debris is a relatively new field and represents a huge new area of research. The two main branches of this thesis are (a) modelling the torques that induce spin for objects in orbit, and (b) modelling the effect of certain attitude-dependent non-conservative forces on spinning objects in orbit. The main torque modelled in this study is solar radiation pressure (SRP). Simulations of the radiation-induced torques are performed and the main mechanisms that lead to the tumbling of uncontrolled objects are analysed. A novel method of presenting attitude-dependent forces and torques on space objects, dubbed ”Torque Maps”, is presented. Radiation torques are caused by optical geometric asymmetry and can lead to oscillatory and secular changes in attitude. They are computed for one of the largest objects in orbit: Envisat, a defunct satellite with complex geometry. Further to these, simulations of objects spinning in orbit are used to calculate the effect of tumbling on orbital motion. The results show that the effects of nonconservative forces on tumbling objects lead to both periodic and secular variations in their orbital elements. This is contrary to previously popular assumption. Additionally, ideas for utilising modern developments in nanosatellite technology for validation of orbit prediction models are presented and calculations of the Lorentz force and its effect for uncontrolled objects are given.
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Biehl, James Patrick. "FORMULATION OF A SEARCH STRATEGY FOR SPACE DEBRIS AT GEO." DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/355.
Full textAbstract:
The main purpose of this thesis is to develop a search strategy for space debris that are in the geosynchronous orbit (GEO) region. The search strategy is not an effort to find the object initially but rather if found one time to aid in finding it again within a small time frame. This was a request from NASA Johnson Space Center Orbital Debris Program Office through the MODEST, Michigan Orbital Debris Survey Telescope, program. A single definitive search pattern was not found, however depending on the COEs of the orbit specific search strategy can be employed. These search strategies are far from perfect and can be improved upon with more rigorous testing as well as a larger data sample. Another goal is to look for correlation between the orbital parameters and the errors in the predicted right ascension (RA) and the declination (DEC). This was accomplished by varying the different orbital parameters by ±10% individually while holding the other parameters constant. This showed some correlation existed between some parameters and their errors, in particular there was correlation between a variation in right ascension of ascending node (RAAN) and the value of RAAN itself. The correlation found was that with the higher the value of RAAN the larger the RMS error.
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Fransson, Jonathan, and Elon Olsson. "Visualization of Space Debris using Orbital Representation and Volume Rendering." Thesis, Linköpings universitet, Medie- och Informationsteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-162162.
Full textAbstract:
This report covers a master’s thesis project done at the University Of Utah for the OpenSpace project. OpenSpace is a open-source astronomy visualization software and the thesis focus was to visualize the ever-increasing number of man-made space debris. Two different visualization methods have been used in this thesis. One was a volume rendering and it was evaluated how it works in relation to an orbital trail representation, which was the other method. If the volumetric representation would reduce cluttering, is one of the aspects that will be evaluated, as well as a more open ended exploratory question which is if the volumetric representation can provide any new insights about the data. In short, will a volumetric representation give anything that an orbital representation cannot? A volume rendering can use different types of grids. The thesis evaluates the pros and cons of a cartesian- and spherical grid, as well as the different resolution of the grid and tweaks in the transfer function. An orbital trail representation was previously implemented in OpenSpace (which will be called the individual scene graph node implementation in this report) that had its pros. One con, however, was that it did not scale very well with increasing number of data elements. Visualizing all the data sets containing each trackable piece of space debris simultaneously using this implementation causes the software to slow down significantly. An alternative implementation (which will be called single draw call implementation in this report) was therefore tested in hopes to solve this issue. To see the performance difference, tests were performed where frame time for the whole scene was measured.
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Maury, Thibaut. "Consideration of space debris in the life cycle assessment framework." Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0051/document.
Full textAbstract:
L’analyse de cycle de vie environnementale (ACV), d’après l’ISO 14040/44, a été identifiée par l’agence spatiale Européenne, ArianeGroup et plusieurs acteurs de l’industrie spatiale européenne comme la méthodologie la mieux adaptée pour réaliser l’évaluation environnementale des missions spatiales. Cependant, le secteur spatial est un domaine d’activité dont la particularité est de s’étendre au-delà des limites de l’environnement terrestre. Ainsi, s’il est possible d’évaluer les impacts sur l’environnement classique via la méthodologie ACV, les impacts générés sur l’environnement orbital ne sont aujourd’hui pas considérés dans son cadre de référence.Par conséquent, il s’agit ici d’étendre le champ des études ACV dans le domaine du spatial afin de caractériser les étapes du cycle de vie ayant lieu en orbite, c’est-à-dire la phase d’usage pendant la mission spatiale et la phase de fin de vie (ou Post-Mission Disposal). L’anticipation de cette dernière est devenue une étape cruciale dans la conception des missions spatiales du fait des règlementations visant à limiter la prolifération des débris spatiaux. En effet, seulement 6% de la population en orbite autour de la Terre sont des satellites actifs, le reste étant considéré comme des débris, résultat des missions et activités spatiales passées. Etant donné cet enjeu de durabilité majeur pour l'industrie spatiale, les études environnementales se doivent de mettre en évidence les transferts de pollution potentiels non seulement entre les impacts environnementaux classiques tels que Changement Climatique ou la Toxicité mais aussi ceux relatifs à l’environnement orbital, au premier rang desquels figurent les débris spatiaux.Afin de caractériser cet impact sur l’environnement orbital, nous proposons de définir une nouvelle catégorie d’impact en ACV dénommée ‘Orbital Space Use’. La conformité avec le cadre de référence de l’ACV est assurée au travers de la construction de chaines de cause-à-effet (ou impact pathways) reliant les flux élémentaires du système d’étude aux mécanismes environnementaux (indicateur midpoint) et au dommage final (indicateur endpoint) au sein de l’Aire de Protection ‘Ressources Naturelles’. En effet, les orbites proches de la Terre qui supportent les activités spatiales sont considérées à ce titre comme une ressource pouvant être impactée par des ‘stresseurs’. Les débris spatiaux sont aujourd’hui identifiés comme les principaux ‘stresseurs’ vis-à-vis de l’accès et de la pleine utilisation de la ressource orbitale. Ainsi, le développement d’un modèle de caractérisation a été entrepris. Il permet d’évaluer l’impact potentiel d’une mission spatiale sur la population des débris déjà présente en orbite. Les facteurs de caractérisation obtenus sont appliqués à un cas d’étude comparant trois scénarios de fin de vie différents dans le but de prouver l’applicabilité du modèle. En outre, une première approche s’intéressant à la quantification des externalités économiques négatives engendrées par la prolifération des débris est développée. Elle constitue une étape préliminaire en vue d’un développement d’une catégorie de dommage dite ‘endpoint’. Enfin, les challenges méthodologiques restants et les potentiels développements complémentaires sont abordésSeveral actors of or related to the European space industry, such as ArianeGroup and the European Space Agency (ESA), have identified life cycle assessment (according to ISO14040/44) as the most appropriate methodology to measure and minimise their environmental impact. Nevertheless, space systems deal with a strong particularity which adds new aspects considering the scope of the LCA framework. Space missions are the only human activity that crosses all segments of the atmosphere and stays “out” of the natural environment and ecosystems. Regarding space systems with a holistic approach, environmental impacts could occur not only in the conventional ecosphere but also in the outer space (i.e. the orbital environment).Consequently, the current scope of LCA studies should be broadened to take into account the on-orbit lifetime as well as the end-of-life disposal of the spacecraft. Yet, it is becoming a crucial point of the space mission design due to the future increase of the orbital population composed in a major part by space debris. In this way, LCA studies of space missions could indicate trade-offs not only between typical impact categories (toxicity and climate change for example) but also with regard to impacts generated in the orbital environment with a particular focus on space debris related impacts.Hence, the priority has been given to the integration of a new impact category called orbital space use in the life cycle impact assessment framework. To address the environmental burdens comprehensively in this new category, impact pathways linking elementary flows to environmental mechanisms (midpoint) and damages (endpoint) are developed within the Area-of-Protection ‘Natural resources’. Space debris is identified as the main stressor of the orbital environment. Thus, ‘characterisation factors’ are defined and calculated at midpoint level to assess the potential impact of a space mission on the orbital environment. The methodology is applied to a case study to prove its applicability: the potential impact of a theoretical space mission is addressed through the comparison of three disposal scenarios. Also, a first attempt regarding the characterisation of the endpoint damage is provided taking into account the economic externalities caused by space debris. Finally, remaining methodological challenges and perspectives for future work are provided
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Maury, Thibaut. "Consideration of space debris in the life cycle assessment framework." Electronic Thesis or Diss., Bordeaux, 2019. http://www.theses.fr/2019BORD0051.
Full textAbstract:
L’analyse de cycle de vie environnementale (ACV), d’après l’ISO 14040/44, a été identifiée par l’agence spatiale Européenne, ArianeGroup et plusieurs acteurs de l’industrie spatiale européenne comme la méthodologie la mieux adaptée pour réaliser l’évaluation environnementale des missions spatiales. Cependant, le secteur spatial est un domaine d’activité dont la particularité est de s’étendre au-delà des limites de l’environnement terrestre. Ainsi, s’il est possible d’évaluer les impacts sur l’environnement classique via la méthodologie ACV, les impacts générés sur l’environnement orbital ne sont aujourd’hui pas considérés dans son cadre de référence.Par conséquent, il s’agit ici d’étendre le champ des études ACV dans le domaine du spatial afin de caractériser les étapes du cycle de vie ayant lieu en orbite, c’est-à-dire la phase d’usage pendant la mission spatiale et la phase de fin de vie (ou Post-Mission Disposal). L’anticipation de cette dernière est devenue une étape cruciale dans la conception des missions spatiales du fait des règlementations visant à limiter la prolifération des débris spatiaux. En effet, seulement 6% de la population en orbite autour de la Terre sont des satellites actifs, le reste étant considéré comme des débris, résultat des missions et activités spatiales passées. Etant donné cet enjeu de durabilité majeur pour l'industrie spatiale, les études environnementales se doivent de mettre en évidence les transferts de pollution potentiels non seulement entre les impacts environnementaux classiques tels que Changement Climatique ou la Toxicité mais aussi ceux relatifs à l’environnement orbital, au premier rang desquels figurent les débris spatiaux.Afin de caractériser cet impact sur l’environnement orbital, nous proposons de définir une nouvelle catégorie d’impact en ACV dénommée ‘Orbital Space Use’. La conformité avec le cadre de référence de l’ACV est assurée au travers de la construction de chaines de cause-à-effet (ou impact pathways) reliant les flux élémentaires du système d’étude aux mécanismes environnementaux (indicateur midpoint) et au dommage final (indicateur endpoint) au sein de l’Aire de Protection ‘Ressources Naturelles’. En effet, les orbites proches de la Terre qui supportent les activités spatiales sont considérées à ce titre comme une ressource pouvant être impactée par des ‘stresseurs’. Les débris spatiaux sont aujourd’hui identifiés comme les principaux ‘stresseurs’ vis-à-vis de l’accès et de la pleine utilisation de la ressource orbitale. Ainsi, le développement d’un modèle de caractérisation a été entrepris. Il permet d’évaluer l’impact potentiel d’une mission spatiale sur la population des débris déjà présente en orbite. Les facteurs de caractérisation obtenus sont appliqués à un cas d’étude comparant trois scénarios de fin de vie différents dans le but de prouver l’applicabilité du modèle. En outre, une première approche s’intéressant à la quantification des externalités économiques négatives engendrées par la prolifération des débris est développée. Elle constitue une étape préliminaire en vue d’un développement d’une catégorie de dommage dite ‘endpoint’. Enfin, les challenges méthodologiques restants et les potentiels développements complémentaires sont abordésSeveral actors of or related to the European space industry, such as ArianeGroup and the European Space Agency (ESA), have identified life cycle assessment (according to ISO14040/44) as the most appropriate methodology to measure and minimise their environmental impact. Nevertheless, space systems deal with a strong particularity which adds new aspects considering the scope of the LCA framework. Space missions are the only human activity that crosses all segments of the atmosphere and stays “out” of the natural environment and ecosystems. Regarding space systems with a holistic approach, environmental impacts could occur not only in the conventional ecosphere but also in the outer space (i.e. the orbital environment).Consequently, the current scope of LCA studies should be broadened to take into account the on-orbit lifetime as well as the end-of-life disposal of the spacecraft. Yet, it is becoming a crucial point of the space mission design due to the future increase of the orbital population composed in a major part by space debris. In this way, LCA studies of space missions could indicate trade-offs not only between typical impact categories (toxicity and climate change for example) but also with regard to impacts generated in the orbital environment with a particular focus on space debris related impacts.Hence, the priority has been given to the integration of a new impact category called orbital space use in the life cycle impact assessment framework. To address the environmental burdens comprehensively in this new category, impact pathways linking elementary flows to environmental mechanisms (midpoint) and damages (endpoint) are developed within the Area-of-Protection ‘Natural resources’. Space debris is identified as the main stressor of the orbital environment. Thus, ‘characterisation factors’ are defined and calculated at midpoint level to assess the potential impact of a space mission on the orbital environment. The methodology is applied to a case study to prove its applicability: the potential impact of a theoretical space mission is addressed through the comparison of three disposal scenarios. Also, a first attempt regarding the characterisation of the endpoint damage is provided taking into account the economic externalities caused by space debris. Finally, remaining methodological challenges and perspectives for future work are provided
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Robledo, Luis. "ANALYSIS AND INTEGRATION OF A DEBRIS MODEL IN THE VIRTUAL RANGE PROJEC." Master's thesis, University of Central Florida, 2004. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2574.
Full textAbstract:
After the accident of the STS 107 Columbia Space Shuttle, great concern has been focused on the risk associated to the population on the ground. Before this accident happened, re-entry routes as well as risk calculation of were not of public concern. Two issues that have been raised from this lamentable accident relate to spacecraft security and to public safety. The integration of a debris model has been part of the original conceptual architecture of the Virtual Range Project. Its integration has been considered as a specific research due to the complexity of the models and the difficulties to obtain them since the commercial off-the-shelf available software seems to be less accessible. This research provides solid information concerning what debris fragmentation models are, their fundamentals, their weaknesses and strengths. The research provides information of the main debris models being currently used by NASA which have direct relationship with the space programs conducted. This study also addresses the integration of a debris model into the Virtual Range Project. We created a provisional model based on the distribution of the Columbia debris fragments over Texas and part of Louisiana in order to create an analytical methodology as well. This analysis shows a way of integrating this debris model with a Geographic Information System as well as the integration of several raster and vector data sets which will provide the source data to compute the calculations. This research uses population data sets that allow the determination of the number of people at risk on the ground. The graphical and numerical analysis made can lead to the determination of new and more secure re-entry trajectories as well as further population-related security issues concerning this type of flights.M.S.
Department of Industrial Engineering and Management Systems
Engineering and Computer Science
Modeling and Simulation
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Baron, John Michael. "Microparticle hypervelocity impacts on satellites in low-Earth orbit." Thesis, University of Kent, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308822.
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Kalinski, Michael E. "Hypervelocity impact analysis of International Space Station Whipple and Enhanced Stuffed Whipple Shields." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Dec%5FKalinski.pdf.
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Thesis (M.S. in Astronautical Engineering)--Naval Postgraduate School, Dec. 2004.Thesis Advisor(s): Eric Christiansen, Terry R. McNelley. Includes bibliographical references (p. 275-276) Also available online.
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Deshpande, Sunil Prabhakar. "Space debris or natural? Impacts on NASA's Long Duration Exposure Facility." Thesis, University of Kent, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335207.
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Tanner, William Graydon. "Meteoroids and space debris hypervelocity impact penetrations : the role of hydrocodes." Thesis, University of Kent, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.319235.
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Mwabi, Christelle Tumba. "Space debris : legal rules for its mitigation and perspectives on remediation." Diss., University of Pretoria, 2019. http://hdl.handle.net/2263/76737.
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Dhondea, Ashiv Rao. "Mission Planning Tool for space debris studies with the MeerKAT radar." Master's thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/29617.
Full textAbstract:
The Radar Remote Sensing Group at the University of Cape Town is currently investigating the feasibility of building an active radar system employing the MeerKAT radio telescope as receiver for space debris detection, tracking and imaging. This dissertation details the development of a Mission Planning Tool (MPT) to perform sensor scheduling and to support the performance prediction and analysis of the proposed MeerKAT radar. The MeerKAT radar project proposal is made in the context of developing space surveillance and tracking capacities in South Africa. The MeerKAT radar is intended to operate bistatically, with a transmitter located in Bredasdorp (South Africa) and the MeerKAT radio telescope as receiver. The system design and radar signal processing design are currently under development in another RRSG project. Before the feasibility study can progress further, a Mission Planning Tool has been developed to assist in scheduling the bistatic radar to perform an observation experiment, to calculate the predicted radar measurements and errors as well as to estimate the orbit of the observed object. This report documents how these objectives were met by the MPT software developed in Python. Given a LEO space object of interest’s Two Line Element set, the MPT performs orbit propagation with an SGP4 method to generate trajectories for radar performance evaluation. The MPT determines the most opportune epoch (the longest possible target dwell-time within the antenna beam) for executing an observation experiment with the MeerKAT radar. Space objects investigated in this project were found to be have spent between 4.5 s to 12.8 s in the transmitter’s illuminating beam. The MeerKAT radio telescopes are tasked to act as receivers at the appropriate antenna pointing and time period. Based on the bistatic geometry of the specific observation experiment, the MPT predicts the signal-to-noise ratio at the radar receiver as well as the bistatic range, bistatic Doppler shift and look angles. The integrated SNR values for the experiments considered in this report ranged from 11 dB to 68 dB. From the coherently integrated SNR, the MPT estimates the radar measurement errors. Finally, the orbit determination module was engineered with two radar measurement schemes: a bistatic range and Doppler shift scheme and a bistatic range and look angles scheme. Monte Carlo experiments were run to evaluate the tracking performance resulting from the two tracking schemes. The Gauss-Newton tracking filter based on the first scheme fails to converge whereas it produces accurate results with the second scheme (estimated position error of 2 m and velocity error of 0.08 m/s). It is therefore recommended to opt for the bistatic range and look angles measurement scheme in future work. Since the current MeerKAT radar design cannot create look angles measurements, an observables estimation scheme was adopted. It was found that this scheme produced accurate elevation and azimuth angles with an estimation error of ±0.04◦ . Since the quoted values result from a preliminary design of the MeerKAT radar, they are bound to change in the final design. Therefore the MPT should be loaded with the final radar design’s parameters and run again to produce useful results. This reports shows that, with the help of the Mission Planning Tool developed in this project, the proposed MeerKAT radar can be feasibly scheduled to observe and track space objects in the LEO regime based on a single target pass.
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Jackson, Daniel J. "Formulation of an Optimal Search Strategy for Space Debris At GEO." DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/656.
Full textAbstract:
The purpose of this thesis is to create a search strategy to find orbital debris when the object fails to appear in the sky at its predicted location. This project is for NASA Johnson Space Center Orbital Debris Program Office through the MODEST (Michigan Orbital Debris Survey Telescope) program. This thesis will build upon the research already done by James Biehl in “Formulation of a Search Strategy for Space Debris at GEO.” MODEST tracks objects at a specific right ascension and declination. A circular orbit assumption is then used to predict the location of the object at a later time. Another telescope performs a follow-up to the original observation to provide a more accurate orbit predication. This thesis develops a search strategy when the follow-up is not successful. A general search strategy for finding space debris was developed based on previous observations. A GUI was also generated to find a search strategy in real-time for a specific object based upon previous observations of that object.
Search strategies were found by adding a 2% mean random error to the position and velocity vectors. Adding a random error allows for finding the most likely location of space debris when the orbital elements are slightly incorrect. A bivariate kernel density estimator was used to find the probability density function. The probability density function was used to find the most probable location of an object. A correlation between error in the orbital elements and error in right ascension and declination root mean square (RMS) error was investigated. It was found that the orbital elements affect the RMS error nonlinearly, but the relation between orbital element and error depended on the object and no general pattern was found. It was found that how long after the original object was found until the follow-up was attempted did not have a large impact on the probability density function or the search strategy.
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Hart, Brandon L. "Anti-satellite weapons : threats, laws and the uncertain future of space." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=100241.
Full textAbstract:
Satellite capabilities greatly enhance both the military and civilian sectors of society. Anti-satellite (ASAT) weapons pose a serious risk to all satellites. Chapter One of this thesis discusses current satellite capabilities. Chapter Two, details the wide variety of ASAT weapons. Chapter Three turns to the intentions of various States to employ ASATs. Chapter Four analyzes the legal implications of using force against satellites---beginning with the laws relating to the use of force in general, including the right of self-defense, and then progressing through relevant provisions of the laws of armed conflict. It also addresses the debate over the militarization and weaponization of outer space and past efforts at non-proliferation that relate to space activities. Chapter Five addresses the creation of space debris---a side effect of ASAT use. I will conclude with a short discussion regarding the potential for a new international agreement restricting the use of ASATs.
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Stucky, Michael S. "Analysis of the NASA shuttle hypervelocity impact database." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03sep%5FStucky.pdf.
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Thesis (M.S. in Space Systems Operations)--Naval Postgraduate School, September 2003.Thesis advisor(s): Eric Christiansen, Rudy Panholzer, Dan Bursch. Includes bibliographical references (p. 75-76). Also available online.
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Sullivan, Kenneth. "Characterisation and dynamic modelling of the near-Earth space particulate environment." Thesis, University of Kent, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303166.
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Schmitz, Manuel [Verfasser], and Stefanos [Akademischer Betreuer] Fasoulas. "Active removal of space debris with space-based lasers : performance and requirements / Manuel Schmitz ; Betreuer: Stefanos Fasoulas." Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2016. http://d-nb.info/1127580531/34.
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Ekweozoh, Irene. "Rethinking state responsiblity in international space "environmental" law: a case for collective responsibility for space debris prevention." Thesis, McGill University, 2014. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=121488.
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This thesis assesses the current legal regime of State Responsibility in the exploration and use of outer space as it concerns space debris prevention. It argues that the proliferation of space debris is attributable to a lack of clarity in the current regime regarding the duty imposed on state and non-state actors for its prevention. It is contended that this concern must be addressed through regulation in order to be meaningful. In support, it interrogates the current status quo of state responsibility for the space activities of non-state entities and how this differs from state responsibility in international environmental law. The objective is to show that the vicarious responsibility of states for non-state actors under current international space law and the disharmony between international space law and environmental law reinforces irresponsible conduct in space activity. As a preventive measure, it advocates for a return to the jurisprudence on "Mankind" that was the basis of the Outer Space Treaty. It suggests that concern for "all mankind" can be used to impose a duty of due regard on all space actors. In this regard, it advances a case for collective responsibility of all space actors by recommending a "Protocol on Collective Responsibility in the Prevention of Space Debris" to be executed by all space actors as a mandatory mechanism to compel the pursuit of uniform space debris prevention measures.La présente thèse décrit le régime légal de responsabilité des Etats dans l'exploration et l'utilisation de l'espace en ce qui concerne la lutte contre les débris spatiaux. Un régime obscur quant aux devoirs des Etats et autres acteurs est à l'origine de la prolifération de ces débris. Ce problème doit être réglé par la voie réglementaire, afin d'avoir un impact efficace. Pour ce faire, le présent statu quo dans la responsabilité des Etats pour les activités de leurs nationaux dans l'espace est étudié. L'objectif est de démontrer que la responsabilité du fait d'autrui des Etats dans le cadre du présent droit international de l'espace ainsi que la discorde qui existe entre ce dernier et le droit environnemental encourage les comportements irresponsables dans les activités spatiales. Comme mesure préventive, la présente thèse propose un retour à la doctrine de « l'humanité » qui était à la base du Traité de l'espace. La prise en compte de « toute l'humanité » peut permettre d'imposer un devoir de respect à tous les acteurs de l'espace. A cette fin, cette thèse propose un régime de responsabilité collective de tous ces acteurs au travers d'un « Protocole sur la responsabilité collective pour la limitation des débris spatiaux » qui serait signé par ceux-ci. Ce mécanisme obligatoire imposerait l'adoption de mesures uniformes de lutte contre les débris spatiaux.
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Logday, Ayesha. "Space Debris and the BRICS countries: The role of international Environmental Law." University of Western Cape, 2019. http://hdl.handle.net/11394/7579.
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Magister Legum - LLMEnvironmental Law is at the forefront of the global community and environmental protection and conservation is regarded as of the utmost importance.1 Outer Space is a unique, limited, and valuable resource. Outer space allows states to utilise thousands of satellites for research, national defence, and communications. At the inception of space law, only a few states dominated space activities and all human space activities were so challenging that nearly any method seemed acceptable for placing objects in outer space, currently more countries have space industries and launch capabilities
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Dow, K. L., M. V. Sykes, F. J. Low, and F. Vilas. "Detection of Earth Orbiting Objects by IRAS." Steward Observatory, The University of Arizona (Tucson, Arizona), 1989. http://hdl.handle.net/10150/623903.
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A systematic examination of 1836 images of the sky constructed from scans made by the Infrared Astronomical Satellite has resulted in the detection of 466 objects which are shown to be in Earth orbit. Analysis of the spatial and size distribution and thermal properties of these objects, which may include payloads, rocket bodies and debris particles, is being conducted as one step in a feasibility study for space -based debris
detection technologies.
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Graham, Giles Andrew. "The mineralogy and chemistry of micrometeorites." Thesis, n.p, 2000. http://oro.open.ac.uk/19214/.
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Wegener, Peter [Verfasser]. "Modelling and Validation of the Space Debris Flux onto Satellites / Peter Wegener." Aachen : Shaker, 2004. http://d-nb.info/1181602777/34.
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