MOST, Micro-variability of Oscillations of STars, microsatellite structural analysis and design

grantor: University of TorontoThis work deals with the structural design and analysis of the Microvariability of Oscillations of Stars (MOST) microsat mission: Canada's first microsatellite mission and first space telescope. The preliminary study phase of the MOST mission proposes the use of the UoSAT tray stack concept as the primary bus structure. However, due to the size and requirements of the science payload (telescope enclosure), an alternative suitcase size structure (keeping the idea of a tray stack as the spinal bone of the primary structure) is conceptualised. Preliminary finite element analyses included herein highlight certain design weaknesses. Design recommendations are formulated and lead to the critical design of the MOST structure. As the design phases progress, the finite element models are refined, both at the component and at the spacecraft level. In an attempt to minimise the design cost, and following the AMSAT cost-effective philosophy, minimal mechanical testing is planned for the MOST mission. Hence, the spacecraft analysis via finite element methods is used herein to ensure structural reliability. The resulting safety margins, when the worst case load scenario is considered, adds confidence by largely surpassing the potential errors introduced by domain discretization and element formulation. The analyses confirm the MOST structure design to be adequate. Finally, this work presents a detailed engineering analysis leading to the design of the MOST tie rods structural component. The tray stack conceptual design offers great advantages in terms of the ease of assembly. However, the sizing of tie rods for small satellites using a tray stack as a primary structure remains a challenging design problem. This work addresses the issues pertaining to tie rod design, and concludes with the appropriate tie rod design recommendations.M.A.Sc