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Thermal Design and Analysis Methodologies Applied to the DAUNTLESS Bus and Ghgsat-C Microsatellite

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Thermal Design and Analysis Methodologies Applied to the DAUNTLESS Bus and Ghgsat-C Microsatellite Thermal Design and Analysis Methodologies Applied to the DAUNTLESS Bus and GHGSat-C Microsatellite by Nicholas Sciullo-Velenosi A thesis submitted in conformity with the requirements for the degree of Master of Applied Science Institute for Aerospace Studies University of Toronto © Copyright by Nicholas Sciullo-Velenosi 2018 ii Abstract Thermal Design and Analysis Methodologies Applied to the DAUNTLESS Bus and GHGSat-C Microsatellite Nicholas Sciullo-Velenosi Master of Applied Science Institute for Aerospace Studies University of Toronto 2018 Throughout a mission’s preliminary design through to final acceptance, various thermal analysis and control techniques are implemented to verify feasibility through worst case hot and cold conditions. A satellite developed using the DAUNTLESS bus, the latest platform developed at SFL, faced many thermal challenges due to the large bus with an emphasis on methodologies to reduce risk. This resulted in a detailed thermal model leading up to the launch of the spacecraft, capturing details around the large antenna dish and the internal propulsion tank. GHGSat-C is a greenhouse gas monitoring satellite with high-resolution IR imaging capabilities. The satellite is a successor to the pre-existing GHGSat-D, which demonstrated the mission and its future constellation. The satellite features updates in almost every subsystem and introduces an optical downlink which drives aspects of the design. These topics are expanded on further in this thesis and any major milestones and results are presented accordingly. iii Acknowledgments Dr. Robert E. Zee, thank you for offering me the opportunity to be part of the best Canadian space team. SFL is a special place where we are all free to celebrate our passion and come together for developing and launching exciting space missions. You are somehow simultaneously firm and understanding towards students like myself and I will always appreciate your interest in providing me the resources I needed to explore my abilities. I would also like to thank my project managers and mentors for patiently nudging me in the right direction and openly answering my questions. Thank you guiding me and trusting my abilities when it often feels like the more one learns, the less we actually know. Thanks also for being strong leaders and somehow always instilling confidence in my ability to work on these projects. To my fellow classmates and roommates, thank you for making Toronto feel like another home and supporting me when I was down. I wish for a future where our paths will cross again. For my friends from Montreal, you have no idea how much it meant to me to have your support when you came to visit for the weekends. We had so much fun and I know that we will always be there for each other when it truly counts. To my wonderful Valentina, you simply bring out the best in me. We managed to constantly encourage and support each other, especially since moving away. I look forwards to all the wondering things our future has to offer together. For my mother and father, I cannot express how my life is rich because of you two. You supported me for 26 years and I could not have asked for a more loving family. You made sure everything was perfect, even for the latest chapter of my life, and I will cherish those moments forever. Unfortunately, it was short lived as my father was diagnosed with cancer. We did everything we could to try and convince ourselves things would be okay. I visited most weekends and our moments together felt timeless, until it was suddenly taken from us. I will never get the chance to share my life with my father again but I am so grateful our last time together was charming and joyful. He showed me the world and I promise to do what I can to leave this world in a better place than I found it too. iv Table of Contents Acknowledgments ........................................................................................................................................ iii Table of Contents ......................................................................................................................................... iv List of Tables .............................................................................................................................................. vii List of Figures ............................................................................................................................................ viii List of Acronyms .......................................................................................................................................... x Introduction.......................................................................................................................................... 1 1.1 Scope ................................................................................................................................................ 2 1.2 Thermal Environment ...................................................................................................................... 2 1.2.1 Low Earth Orbit .................................................................................................................. 3 1.2.2 Sun-Synchronous Orbits ..................................................................................................... 4 1.2.3 Beta Angle .......................................................................................................................... 1 1.2.4 Thermal Sources ................................................................................................................. 4 1.3 Heat Transfer ................................................................................................................................... 6 1.3.1 Conduction .......................................................................................................................... 6 1.3.2 Radiation ............................................................................................................................. 8 1.3.3 Heat Capacity .................................................................................................................... 11 1.4 Control Methods Overview ............................................................................................................ 12 1.4.1 Isolating Spacers ............................................................................................................... 12 1.4.2 Torqued Fasteners ............................................................................................................. 12 1.4.3 Coatings ............................................................................................................................ 13 1.4.4 Heaters .............................................................................................................................. 14 1.5 Modelled Representations .............................................................................................................. 14 1.5.1 Finite Element Method ..................................................................................................... 14 1.5.2 Boundary Conditions ........................................................................................................ 17 1.5.3 Effective Surfaces ............................................................................................................. 18 1.5.4 Resistances ........................................................................................................................ 19 1.5.5 Transient Solutions ........................................................................................................... 22 DAUNTLESS ..................................................................................................................................... 24 2.1 Mission Overview .......................................................................................................................... 24 2.1.1 Mission Requirements ...................................................................................................... 25 v 2.2 Boundary Conditions ..................................................................................................................... 27 2.2.1 Orbits ................................................................................................................................ 29 2.2.2 Heat Dissipation ................................................................................................................ 29 2.3 Design Concepts ............................................................................................................................ 31 2.3.1 Internal Balance ................................................................................................................ 32 2.3.2 External Payload ............................................................................................................... 34 2.4 Studies ............................................................................................................................................ 35 2.4.1 Payload Antenna ............................................................................................................... 36 2.4.2 Propulsion Tank ................................................................................................................ 37 2.4.3 Thermo-Electric Thruster.................................................................................................
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