19 research outputs found

    A Tutorial on the Tracking, Telemetry, and Command (TT&C) for Space Missions

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    This paper presents a tutorial on the Tracking, Telemetry, and Command (TT&C) for spacecraft and satellite missions. In particular, it provides a thorough summary of the design of the TT&C, starting from elementary system aspects and going down to the details of the on-board TT&C subsystem design, its units, and the physical layer. The paper is then complemented with a description of emerging TT&C techniques and technologies, the standardization framework, and practical examples of actual spacecraft design of European space missions. The here-presented tutorial is thought for professionals (also in other telecommunication engineering fields) willing to face the challenges and state-of-the-art of the TT&C, and know more about this fundamental function that allows us to control and monitor our spacecraft on a daily basis

    Cyber-Physical Embedded Systems with Transient Supervisory Command and Control: A Framework for Validating Safety Response in Automated Collision Avoidance Systems

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    The ability to design and engineer complex and dynamical Cyber-Physical Systems (CPS) requires a systematic view that requires a definition of level of automation intent for the system. Since CPS covers a diverse range of systemized implementations of smart and intelligent technologies networked within a system of systems (SoS), the terms “smart” and “intelligent” is frequently used in describing systems that perform complex operations with a reduced need of a human-agent. The difference between this research and most papers in publication on CPS is that most other research focuses on the performance of the CPS rather than on the correctness of its design. However, by using both human and machine agency at different levels of automation, or autonomy, the levels of automation have profound implications and affects to the reliability and safety of the CPS. The human-agent and the machine-agent are in a tidal lock of decision-making using both feedforward and feedback information flows in similar processes, where a transient shift within the level of automation when the CPS is operating can have undesired consequences. As CPS systems become more common, and higher levels of autonomy are embedded within them, the relationship between human-agent and machine-agent also becomes more complex, and the testing methodologies for verification and validation of performance and correctness also become more complex and less clear. A framework then is developed to help the practitioner to understand the difficulties and pitfalls of CPS designs and provides guidance to test engineering design of soft computational systems using combinations of modeling, simulation, and prototyping

    To See the Unseen: A History of Planetary Radar Astronomy

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    This book relates the history of planetary radar astronomy from its origins in radar to the present day and secondarily to bring to light that history as a case of 'Big Equipment but not Big Science'. Chapter One sketches the emergence of radar astronomy as an ongoing scientific activity at Jodrell Bank, where radar research revealed that meteors were part of the solar system. The chief Big Science driving early radar astronomy experiments was ionospheric research. Chapter Two links the Cold War and the Space Race to the first radar experiments attempted on planetary targets, while recounting the initial achievements of planetary radar, namely, the refinement of the astronomical unit and the rotational rate and direction of Venus. Chapter Three discusses early attempts to organize radar astronomy and the efforts at MIT's Lincoln Laboratory, in conjunction with Harvard radio astronomers, to acquire antenna time unfettered by military priorities. Here, the chief Big Science influencing the development of planetary radar astronomy was radio astronomy. Chapter Four spotlights the evolution of planetary radar astronomy at the Jet Propulsion Laboratory, a NASA facility, at Cornell University's Arecibo Observatory, and at Jodrell Bank. A congeries of funding from the military, the National Science Foundation, and finally NASA marked that evolution, which culminated in planetary radar astronomy finding a single Big Science patron, NASA. Chapter Five analyzes planetary radar astronomy as a science using the theoretical framework provided by philosopher of science Thomas Kuhn. Chapter Six explores the shift in planetary radar astronomy beginning in the 1970s that resulted from its financial and institutional relationship with NASA Big Science. Chapter Seven addresses the Magellan mission and its relation to the evolution of planetary radar astronomy from a ground-based to a space-based activity. Chapters Eight and Nine discuss the research carried out at ground-based facilities by this transformed planetary radar astronomy, as well as the upgrading of the Arecibo and Goldstone radars. A technical essay appended to this book provides an overview of planetary radar techniques, especially range-Doppler mapping

    A history of the European Space Agency: 1958-1987

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    Religious experience of the destined human being

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    Bibliography: pages 749-755.Six people fitting the above description of "destined human beings" were studied as far as possible from their own work, i.e. writings, paintings, music, speeches, letters, etc. They were studied on two levels, that of their own metier, and then how they retained that holistic quality which enabled them to remain in touch with a greater vision of life and humanity as a whole. They are Leonardo da Vinci, Rembrandt van Rijn, Johann Sebastian Bach, Winston Churchill, Albert Einstein, and, as an exception to some things which have been said, Pablo Picasso. It is hoped that this research demonstrates that these people understand humanity and its needs for religion, and that their experiences and interpretations thereof help humanity engage those needs sanely and fruitfully. In other words, they enrich religion as a quest. Different senses of identity, modes of engagement, models of reality, methods of expression are examined, all of which demonstrably fit into Cumpsty's Theory of Religion of Belonging. One of the case studies demonstrates what happens when the sense of belonging is impaired. The thesis takes a very broad view of what constitutes religious experience, but the expressions of the case studies can be considered as religion at its best, or most universal

    The documentary novel : fact, fiction or fraud? An examination of three Scandinavian examples of the documentary novel from the 1960s and 1970s

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    This study seeks primarily to examine three Scandinavian examples of the documentary novel. Initially I endeavour to isolate certain purported characteristics of the genre as a whole by considering which aspects of a narrative have prompted the critics to call it a 'documentary novel'. I then examine the three works in detail, applying standard techniques of literary criticism and comparing the facts on which the novels are based with the novels themselves to determine what makes them 'documentary' and what makes them 'novels'.The three novels share common techniques and all deal with the subject of Scandinavian polar exploration, but the author's relationship and attitude to the facts he has at hand are sufficiently different in each instance to permit a discussion of the literary form, ambitions and potential of the 'documentary novel'.The evidence suggests that the documentary novel uses authentic historical material but presents it through the techniques and forms of creative literature: the novelists adapt documented facts to support a view of a history which typically differs from accepted tradition. I then show that the conclusions to which this unorthodox view points, however, are invariably the same as those the authors draw about life in their other, non-documentary fictional works.Finally I demonstrate how the documentary novel is a fluid form which can be used in the service of fact, fiction or fraudulent propaganda, and I suggest a definition that embraces the three novels examined and the three kinds of documentary fiction that they represent

    Decolonizing the Empathic Settler Mind: An Autoethnographic Inquiry

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    Public and scholarly analysis of the troubled relations of Natives and non-Natives (settlers) has been predominantly directed to the former, long-framed as “the Indian Problem.” This dissertation takes the different stance of focusing on the mind-sets of settlers and their society in perpetuating the trans-historical trauma and injustice resulting from foundational acts of dispossession.The approach is autoethnographic:after considering the settler world in which I grew up, critical episodes and developments in my career working with British Columbian First Nations are described and analyzed.This includes working with Kwakwaka’wakw, Haida, Wuikinuxv, Nuxalk and Lheidli T’enneh Nations over a 25-year period.I also look closely at my friendship with a Gitxsan artist, which painfully surfaced our differences and the dangerous colonial practice of settlers’ telling indigenous life stories.Critical themes and learning drawn from this account indicate both some pitfalls and opportunities for empathic settlers to decolonize their minds and actions and thereby contribute to the broader decolonization story of the settler state of Canada.The electronic version of this Dissertation is at Ohiolink ETD Center, http://etd.ohiolink.edu and AURA http://aura.antioch.edu/ A video introduction by the author accompanies this documen

    Critical Issues in the History of Spaceflight

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    At a May 1981 "Proseminar in Space History"held at the Smithsonian Institution's National Air and Space Museum (NASM) in Washington, DC, historians came together to consider the state of the discipline of space history. It was an historic occasion. The community of scholars interested in the history of spaceflight was not large; previously, well-meaning but untrained aficionados consumed with artifacts had dominated the field, to the exclusion of the larger context. At a fundamental level, this proseminar represented a "declaration of independence" for what might be called the "new aerospace history." In retrospect, it may be interpreted as marking the rise of space history as a recognizable subdiscipline within the field of U.S. history. Bringing together a diverse collection of scholars to review the state of the art in space history, this proseminar helped in a fundamental manner to define the field and to chart a course for future research. Its participants set about the task of charting a course for collecting, preserving, and disseminating the history of space exploration within a larger context of space policy and technology. In large measure, the course charted by the participants in this 1981 proseminar aided in advancing a very successful agenda of historical research, writing, and understanding of space history. Not every research project has yielded acceptable results, nor can it be expected to do so, but the sum of the effort since 1981 has been impressive. The opportunities for both the exploration of space and for recording its history have been significant. Both endeavors are noble and aimed at the enhancement of humanity. Whither the history of spaceflight? Only time will tell. But there has been an emergent "new aerospace history" of which space history is a central part that moves beyond an overriding concern for the details of the artifact to emphasize the broader role of the spacecraft. More importantly, it emphasizes the whole technological system, including not just the vehicle but also the other components that make up the aerospace climate, as an integral part of the human experience. It suggests that many unanswered questions spur the development of flight and that inquisitive individuals seek to know that which they do not understand

    Perfect Worlds

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    Perfect Worlds offers an extensive historical analysis of utopian narratives in the Chinese and Euro-American traditions. This comparative study discusses finally the rise of dystopian writing – a negative expression of the utopian impulse – in Europe and America (Zamyatin, Huxley, Orwell, Bradbury, Atwood) as well as in China (Lao She, Wang Shuo, and others). The author observes that the utopian imagination thrives in a context of secularization. It appears that in the twentieth century the distinction between utopia and dystopia is blurred as a result of the increasing autonomy of the reader. Fokkema argues that in modern times utopianism in China and in the West has developed in opposite directions, each appropriating attitudes from the other culture which originally were considered alien
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