Up until 2015 the rate at which cube satellite missions achieved full mission success was only 44.1% for any organizations rst mission (academic or corporate), the success rate increases to only 62% for cube satellites launched as a second mission. This thesis suggests that there are two main sources for the high failure rate: improper veri cation, and the common use of COTS components and their reliability in a space environment. The thesis provides a means of increasing mission assurance through the use of physics of failure reliability estimation models that incorporate the intrinsic and extrinsic failures of thermal mechanical e ects as well as radiation e ects on EEE components, a design methodology is also presented that incorporates reliability modeling as well as thorough software and hardware in loop testing to prevent failure due to improper veri cation. The environment and reliability models are calculated for the on board command and data handling system of the ECOSat- II cube satellite being developed by the University of Victoria ECOSat team using NX Siemens for thermal FEA modelling, SPENVIS for radiation environment, and MATLAB for reliability calculation. / Graduate / 0544 / 0538 / cass.hussmann@gmail.com

Recently, The Land, Air and Space Robotics (LASR) Laboratory has demonstrated a state-of-the-art proximity operations test bed that will revolutionize the concept of portable space systems simulation. The Holonomic Omni-directional Motion Emulation Robot (HOMER) permits in nite, un-tethered circumnavigations of one object by another. To allow this platform to operate at the desired performance, an appropriate implementation of feedback control is essential. The dynamic model is derived and presented using a Lagrangian approach. A Lyapunov method is used to form proportional-derivative (PD) and proportional-integral-derivative (PID) feedback controllers. These controllers are validated with computer-based simulation and compared through experimental results. Finally, a frequency analysis is performed in an effort to identify the bandwidth of the system and provide a better understanding of the expected system performance for reference motions containing harmonic perturbations.

Approved for public release; distribution is unlimited / Image navigation is critical to the effective use of digital imagery for meteorological and oceanographic studies. This thesis reviews various methods used to navigate imagery to the earth and investigates the accuracy of the Naval Postgraduate School (NPS) model. An explanation of how the NPS navigation process works is included for completeness. Results from 2 2 separate runs of the NPS model are studied. / http://archive.org/details/accuracyofsatell00beth / Captain, United States Marine Corps

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1990. / Includes bibliographical references (p. 129-130). / Sponsored by NASA. NAGW-21 / Terrence W. Fong. / M.S.

NASA's current plans for human spaceflight include an evolutionary series of missions based on a steady increase in capability to explore cis-lunar space, the Moon, near-Earth asteroids, and eventually Mars. Although the system architecture definition has the greatest impact on the eventual performance and cost of an exploration program, selecting an optimal architecture is a difficult task due to the lack of methods to adequately explore the architecture design space and the resource-intensive nature of architecture analysis. This research presents a modeling framework to mathematically represent and analyze the space system architecture design space using graph theory. The framework enables rapid exploration of the design space without the need to limit trade options or the need for user interaction during the exploration process. The architecture design space for three missions in a notional evolutionary exploration program, which includes staging locations, vehicle implementation, and system functionality, for each mission destination is explored. Using relative net present value of various system architecture options, the design space exploration reveals that the launch vehicle selection is the primary driver in reducing cost, and other options, such as propellant type, staging location, and aggregation strategy, provide less impact.

This thesis describes technologies developed for nanosatellites at the Space Flight Laboratory. A critical ground station component, the Terminal Node Controller, was upgraded in order to support Generic Nanosatellite Bus and future missions. Sun sensor requirements and operation were reviewed, followed by details of the author's work in executing the acceptance testing on these parts, including thermal shock testing, thermal functional testing, calibration, system level testing and on orbit commissioning. A new calibration test process was developed, along with supporting structure and software to ease the testing process, producing accurate calibration parameters and expected performance results for the sensors. A thermal qualification campaign was completed, demonstrating that sun sensors are capable of functioning with negligible performance degradation after exposure to extreme temperatures. A process for installing the sun sensor pin hole was developed using photolithography. Finally, power subsystem analysis for the NEMO-AM mission is presented.

This thesis describes technologies developed for nanosatellites at the Space Flight Laboratory. A critical ground station component, the Terminal Node Controller, was upgraded in order to support Generic Nanosatellite Bus and future missions. Sun sensor requirements and operation were reviewed, followed by details of the author's work in executing the acceptance testing on these parts, including thermal shock testing, thermal functional testing, calibration, system level testing and on orbit commissioning. A new calibration test process was developed, along with supporting structure and software to ease the testing process, producing accurate calibration parameters and expected performance results for the sensors. A thermal qualification campaign was completed, demonstrating that sun sensors are capable of functioning with negligible performance degradation after exposure to extreme temperatures. A process for installing the sun sensor pin hole was developed using photolithography. Finally, power subsystem analysis for the NEMO-AM mission is presented.

Space system development is a complex process that typically involves multiple stakeholders. Traditionally, information is captured and exchanged in the form of documents. Efficient exchange of information is crucial, but often challenging with the traditional document-based approach and multitude of stakeholders. In addition to the challenges in information exchange, currently there is also pressure on the cost and schedule requirements of space projects. European Space Agency (ESA) proposes digitalisation as one of the solutions to these challenges, and more specifically, a transition from document-based approach to model-based. ESA’s vision is to implement digitalisation in the form of an infrastructure to support MBSE processes, named the System Factory. This System Factory needs a centralised data hub that provides interoperability between different stakeholders and tools used throughout space system development life cycle. The purpose of the hub is also to allow the stakeholders to exchange information using common semantics, described in the space system ontology (SSO). Model-Based Engineering Hub (MBEH) is an ESA project, implemented by RHEA Group, Thales Alenia Space, OHB and DEKonsult. The overall objectives of the project are to scope the MBSE hub, provide a technical solution for it and demonstrate its functionality with two use cases. The selected use cases are exchanges between operations (OPS) and systems engineering (ENG) domains, and reliability, availability, maintainability and safety (RAMS) and systems engineering domains. The objective of this thesis is to develop a conceptual data model (CDM) of the operations use case to support the MBEH project. The CDM was developed in two phases. The first task was to analyse and complement the exchanges related to the chosen operations use case based on the European Cooperation for Space Standardization (ECSS) standards. This written analysis was then used as a starting point for modelling, which was the second task. The modelling was performed using the Object Role Modeling (ORM) language and Natural ORM Architect (NORMA) tool. The models are created based on information from OHB and the ECSS standards. The next step in the MBEH project is to harmonise these models with the European Ground Systems Common Core (EGS-CC) and existing ontologies, which were not available for this thesis project.

Coulomb forces acting between close flying charged spacecraft provide near zero propellant relative motion control, albeit with added nonlinear coupling and limited controllability. This novel concept has numerous potential applications, but also many technical challenges. In this dissertation, two- and three-craft Coulomb formations near GEO are investigated, using a rotating Hill frame dynamical model, that includes Debye shielding and differential gravity. Aspects of dynamical systems theory and optimization are applied, for insights regarding stability, and how inherent nonlinear complexities may be beneficially exploited to maintain and maneuver these electrostatic formations. Periodic relative orbits of two spacecraft, enabled by open-loop charge functions, are derived for the first time. These represent a desired extension to more substantially studied, constant charge, static Coulomb formations. An integral of motion is derived for the Hill frame model, and then applied in eliminating otherwise plausible periodic solutions. Stability of orbit families are evaluated using Floquet theory, and asymptotic stability is shown unattainable analytically. Weak stability boundary dynamics arise upon adding Coulomb forces to the relative motion problem, and therefore invariant manifolds are considered, in part, to more efficiently realize formation shape changes. A methodology to formulate and solve two-craft static Coulomb formation reconfigurations, as parameter optimization problems with minimum inertial thrust, is demonstrated. Manifolds are sought to achieve discontinuous transfers, which are then differentially corrected using charge variations and impulsive thrusting. Two nonlinear programming algorithms, gradient and stochastic, are employed as solvers and their performances are compared. Necessary and sufficient existence criteria are derived for three-craft collinear Coulomb formations, and a stability analysis is performed for the resulting discrete equilibrium cases. Each specified configuration is enabled by non-unique charge values, and so a method to compute minimum power solutions is outlined. Certain equilibrium cases are proven maintainable using only charge control, and feedback stabilized simulations demonstrate this. Practical scenarios for extending the optimal reconfiguration method are also discussed. Lastly, particular Hill frame model trajectories are integrated in an inertial frame with primary perturbations and interpolated Debye length variations. This validates qualitative stability properties, reveals particular periodic solutions to exhibit nonlinear boundedness, and illustrates higher-fidelity solution accuracies. / text

Este trabalho analisa as Áreas de Preservação Permanente (APPs) contíguas aos corpos d\'água urbanos como um recurso para a configuração do sistema de espaços livres das cidades brasileiras. Muito embora sua função específica - conforme estabelecido pelo Código Florestal Brasileiro (Lei n° 12.651/2012) - seja proteger recursos hídricos e ecossistemas associados, as APP se consolida, neste início de século XXI, como um importante parâmetro para o planejamento e gestão de orlas fluviais situadas em áreas urbanas, sendo incorporada as políticas de ordenamento do solo e provisão de espaços livres públicos, e estruturando uma série de ações urbanísticas e paisagísticas contemporâneas que se multiplicam pelo país e criam novas formas de aproximação entre as cidades e os seus rios. A espeito dos avanços proporcionados pela lei na proteção dos recursos ambientais existentes nas cidades, a problemática socioambiental e urbanística vinculada a essas áreas exige abordagens menos conservacionistas e mais abrangentes no sentido de considerar as múltiplas funções desempenhadas por essas áreas na complexa e diversa realidade urbana. Entre os diversos caminhos possíveis para esta discussão, o presente trabalho propõe uma abordagem morfológica para avaliar as relações entre as orlas fluviais e as áreas urbanas, e identificar as impressões que a lei produz sobre os espaços livres e suas formas de uso e apropriação. A primeira parte do trabalho se dedica a conceituar a orla fluvial como parte de um sistema urbano e a traçar um panorama sobre os conceitos de planejamento e projetos adotados para o tratamento dessas áreas, destacando um conjunto de ações contemporâneas realizadas no Brasil e no mundo. Na segunda parte, o trabalho avalia a influência da lei sobre a conformação do sistema de espaços livres em diferentes cidades brasileiras, por meio da análise de padrões morfológicos que permitem identificar limitações, conflitos e pontos der aderência da lei ao contexto urbano. Na conclusão, são apresentadas as considerações finais e um panorama sobre os padrões analisados no trabalho, os quais podem servir de referencial metodológico para a formulação de políticas públicas e ações urbanísticas adequadas para uma melhor integração das orlas fluviais às cidades. / This work analyses the Permanet Preservation Areas (APP) adjacent to urban waterbodies as a resort to the conformation of Brazilian cities open spaces system. Although its specific function - as established by the Brazilian Forest Code (Law n. 12.651/2012) - is to protect water resources and associated ecosystems, the APP consolidates itself, in this beginning of the XXI century, as an important parameter to the planning and management of river shores located in urban areas, being incorporated to land management and provision of public open spaces policies, structuring a series of urban and landscape contemporary actions that multiplies throughout the country and create new forms of interface between the cities and its rivers. Despite the advances brought by the law to the protection of cities existing environmental resources, the socio-environmental and urban problems associated to these areas demand less conservationist and more broadening approaches in a way that considers the multiple functions played by these areas in the complex and diverse urban reality. Among the numerous possible ways to this discussion, the present work puts forward a morphological approach to evaluate the relations between river shores and urban areas and identify the fingerprints that the law produces onto the open spaces systems and its forms of use and appropriation. The first part of this work is dedicated to conceptualizing the fluvial shores as a part of an urban system andoutlining an overview on the concepts of planning and design adopted in the treatment of these areas, highlighting a set of ontemporary actions undertaken in Brazil and in the world. In its second part, the work evaluates the influence of the law in the conformation of open spaces system in different Brazilian cities through the analysis of morphological patterns that enables the identification of limitations, conflicts and points of agreement between the law and the urban context. At the conclusion, the final considerations are presented along with a summary table of the analysis criteria adopted in the work, which can serve as methodological benchmarks to the formulation of adequate urban policies and urban actions to a better integration of river shores to the cities.