Optomechanical Optimizations for Balloon-borne Telescopes

Abstract

The evolution of cosmology and our understanding of the universe is driven by continual advancements in observational tools and techniques. This thesis investigates a key area in this evolution, focusing on the optical and mechanical optimization of balloon-borne telescopes. These unique platforms provide several competitive advantages for cosmic microwave background (CMB) studies and gravitational lensing studies, further constraining our cosmological models. Examining three distinct experiments---the Super-pressure Balloon-borne Imaging Telescope (SuperBIT), the Giga-pixel Balloon-borne Imaging Telescope (GigaBIT), and SPIDER, this thesis delves into the intricacies of optomechanical design and alignment. SuperBIT, a 0.5-m wide-field Near-Ultraviolet (NUV) imager, provides crucial insights into weak gravitational lensing effects from galaxy clusters, while GigaBIT, its larger sibling, complements space telescopes in the NUV realm. SPIDER, a balloon-borne polarimeter, targets CMB polarization. This work evaluates the scientific demand for and the unique role of balloon-borne telescopes in NUV imaging, informed by a thorough review of Hubble Space Telescope proposal cycles and instrument utilization. This thesis also elaborates on modeling techniques for estimating optical misalignment when aligning wide-field imaging telescopes. Additionally, it pioneers the use of topology optimization techniques in the design of lightweight yet robust structures vital for these airborne instruments. The results of these investigations are illuminating. It becomes evident that the optimizations laid out are not just beneficial, but critical to realizing the ambitious scientific goals of these experiments within the inherent constraints of the balloon platform. The findings underscore the crucial role of balloon-borne telescopes in furthering cosmological understanding, and in doing so, offer a robust blueprint for designing and optimizing future balloon-borne telescope systems that maximize NUV imaging quality, cost-effectiveness, and efficiency.