Manoeuvre Planning Architecture for the Optimisation of Spacecraft Formation Flying Reconfiguration Manoeuvres

Formation flying of multiple spacecraft collaborating toward the same goal is fast becoming a reality for space mission designers. Often the missions require the spacecraft to perform translational manoeuvres relative to each other to achieve some mission objective. These manoeuvres need to be planned to ensure the safety of the spacecraft in the formation and to optimise fuel management throughout the fleet. In addition to these requirements is it desirable for this manoeuvre planning to occur autonomously within the fleet to reduce operations cost and provide greater planning flexibility for the mission. One such mission that would benefit from this type of manoeuvre planning is the European Space Agency’s DARWIN mission, designed to search for extra-solar Earth-like planets using separated spacecraft interferometry. This thesis presents a Manoeuvre Planning Architecture for the DARWIN mission. The design of the Architecture involves identifying and conceptualising all factors affecting the execution of formation flying manoeuvres at the Sun/Earth libration point L2. A systematic trade-off analysis of these factors is performed and results in a modularised Manoeuvre Planning Architecture for the optimisation of formation flying reconfiguration manoeuvres. The Architecture provides a means for DARWIN to autonomously plan manoeuvres during the reconfiguration mode of the mission. The Architecture consists of a Science Operations Module, a Position Assignment Module, a Trajectory Design Module and a Station-keeping Module that represents a multiple multi-variable optimisation approach to the formation flying manoeuvre planning problem. The manoeuvres are planned to incorporate target selection for maximum science returns, collision avoidance, thruster plume avoidance, manoeuvre duration minimisation and manoeuvre fuel management (including fuel consumption minimisation and formation fuel balancing). With many customisable variables the Architecture can be tuned to give the best performance throughout the mission duration. The implementation of the Architecture highlights the importance of planning formation flying reconfiguration manoeuvres. When compared with a benchmark manoeuvre planning strategy the Architecture demonstrates a performance increase of 27% for manoeuvre scheduling and fuel savings of 40% over a fifty target observation tour. The Architecture designed in this thesis contributes to the field of spacecraft formation flying analysis on various levels. First, the manoeuvre planning is designed at the mission level with considerations for mission operations and station-keeping included in the design. Secondly, the requirements analysis and implementation of Science Operation Module represent a unique insight into the complexity of observation scheduling for exo-planet analysis missions and presents a robust method for autonomously optimising that scheduling. Thirdly, in-depth analyses are performed on DARWIN-based modifications of existing manoeuvre optimisation strategies identifying their strengths and weaknesses and ways to improve them. Finally, though not implemented in this thesis, the design of a Station-keeping Module is provided to add station-keeping optimisation functionality to the Architecture

The Limits of the Present: Hugh of Saint-Victor's 'Pictura' of Noah's Ark and Augustine's 'Distentio Animi'

Imagining the universe from the perspective of providence, the size and complexity of Hugh of Saint-Victor's pictura of Noah's Ark, described in De Pictura Arche (c. 1125–31), has long confused scholars. Many have suggested the text describes a now-lost, real, physical painting; for others it reads as an exclusively verbal picture, an ekphrasis, in the tradition of monastic memory practice. Proponents of the former interpretation argue the density of description defies memory and imagination. But, this paper argues, the pressure the pictura exerts on memory and imagination, as an ekphrasis, might also be seen as central to its rhetorical-spiritual efficacy. In his longer works on the Ark, De Arche Noe Morali and De Vanitate Mundi, Hugh envisages ascent in Augustinian terms, as a stretching of the soul's (or memory's) attention to hold passing times 'as present,' that simulates God's 'eternal present.' Hugh intends, I propose, in keeping with Augustine's distentio animi, that we achieve the pictura's eternal view in the distension of our awareness, our struggle to hold as pictorially 'present' what is described in the time of narrative. As a reworking of the classical, simultaneous 'view from above' along Augustinian lines – as an inner labour, and time-bound exercise – the pictura may also be situated in a new historical-intellectual context: not just as an astonishing example of monastic map-making or mnemotechnical practice, but as part of a later-medieval shift towards thinking about ascent as a coming to terms with time, and eternity as discoverable in the here and now, in the 'limits of the present.

The Attica Prison Riot’s Effect on Corrections Officers, Staffing, and the New York State Prison System

The Uprising at the Attica Correctional Facility in September 1971 was a system-changing event for the New York State Department of Corrections. The impact of the uprising is not only the effect it had on inmate lives and conditions at Attica, but also the effect it had on the corrections officers and the Department of Corrections as a whole. The problems that had been affecting the department of corrections for years were now tangible, because inmates were acting on their unhappiness. The question became: how exactly did this uprising effect not only the corrections officers involved in the event, but also the officers who would work in the wake of the uprising? The papers of Council 82 (the council created to represent the interests of municipal employees, mainly corrections officers) were instrumental in determining the effects and the changes created to make the prisons in New York safer for both the corrections officers and the inmates. In the end, New York State offered money and programs to increase training for officers, increase inmate conditions, and make the prisons safer for both officers and inmates. Attica is the catalyst for change within the prison system of New York State

The Mechanical Arts and Poiesis in the Philosophy and Literature of the Twelfth-Century Schools

The ‘mechanical arts’ or artes mechanicae were first named as a part of Philosophy in Hugh of Saint-Victor’s Didascalicon (1120s). They were identified as seven arts (fabric making, armament, commerce, agriculture, hunting, medicine, and theatrics), and positioned as a parallel to the seven liberal arts. Their inclusion in the Didascalicon has been taken by previous historians to signal a new interest in science and engineering, an effort to ‘give intellectual status to technology for the first time’. This study reconsiders the significance of the mechanical arts for schoolmen working in northern France in the twelfth century. It argues that while this category designated a set of everyday technologies, it also had a more covert, imaginative currency for certain authors – as an image or exemplum for the process of learning. Its procedures and activities could be held up as a mirror to those of the liberal and especially verbal arts, picturing these in the terms of poiesis – an ancient model for philosophy as ‘sense making’ or ‘world making’. This metaphorical utility of the artes mechanicae can be discerned in Hugh’s discussion, running underneath his more literal concern with the mechanical arts as everyday technologies. It was given fullest expression, I argue, in the later allegorical encyclopaedias of ‘Chartrian’ poets, Bernard Silvestris and Alan of Lille (1140s–80s). The final part of the thesis discusses Geoffrey of Vinsauf’s Poetria nova (c. 1215). Here the mechanical arts are enlisted to represent the student of the verbal arts as a technite, a technician and theorist. Geoffrey’s work is often considered a summa of medieval thinking about poet-craft. But its recruitment of the mechanical arts to picture theoretical mastery also marks the end – and a reversal – of the lesser-known invocation of mechanica by twelfth-century authors, the one I trace here: which cast the author and scholar as a maker proper, a ‘poet’ in the ancient sense of that word

Data challenges for the Gaia Science Alerts System

Gaia is a European Space Agency (ESA) cornerstone mission due to launch late 2012. Its mission is to precisely survey over one billion sources to create an accurate three-dimensional map of the sky. The Gaia Science Alerts (GSA) System, based in the Institute of Astronomy (IoA) at Cambridge University in the UK, aims to use the daily data stream from Gaia to look for and report on transient events both from within and beyond our galaxy. The data stream will be processed in near real-time in order to provide rapid alerts to facilitate ground-based follow-up. This paper provides an overview of the Gaia Science Alerts System and highlights the data processing and storage challenges from data ingestion and event-detection to event classification and the eventual publication mechanism

The Division of Health Service Regulation as an Eligible Entity Reporting to the Data Bank

The North Carolina Department of Health and Human Services, Division of Health Service Regulation is required to report and may query the National Practitioners Data Bank and the Health Integrity Protection Data Bank. This thesis provides an overview of the requirements and process for the Division to report to the Data Bank along with suggestions to ensure compliance in an efficient and effective manner. The purpose of the Data Bank is discussed through a review of literature and overview of associated laws. The process and procedure of the database is explained in relation to eligible entities, individual subjects, queries, reports, disputes, and fees. A summary of improvements of the Data Bank delineates the use of public health leadership in operation and improvement of the database.Master of Public Healt