(Georgia Institute of Technology, 2020-01-10)
Hunter, Richard Anthony John
Fast, high-cadence translunar pathfinder missions hold great promise for advancing NASA's scientific observation, prospecting, and technology validation objectives through increased lunar exploration.
This research applies high-performance computing to characterize direct injection lunar trajectories over a broad parameter space, and in so doing, demonstrates the viability of lunar pathfinder missions using the near-future commercial launch market. The results are intended to provide mission designers with an accurate, versatile reference for preliminary planning, including optimal departure epochs, and pertinent performance dependencies.
Characterized herein are statistical distributions for the performance demands of optimally phased translunar missions, over an 18.6 year Earth-Moon nodal cycle, to a range of tailored lunar arrival architectures, for 0 – 24 kg small satellite payloads capable of supporting pathfinder objectives.
This characterization is based upon a TLI stage with flight proven propulsion technology, high fidelity orbital dynamics, and direct injection flyby, orbit insertion and landing architectures compatible with both dedicated and ride share commercial launches.
(Georgia Institute of Technology, 2016-07-28)
Francis, Parker
This thesis presents the design and analysis of a small spacecraft bus for use by the Georgia Tech Space Systems Design Lab. It is designed with research projects in mind, and levies the previous design work of The University of Texas at Austin's Texas Spacecraft Lab. The bus offers capabilities that are competitive to currently available commercial small spacecraft busses. The system has been designed with a variety of missions in mind, and is shown to be capable of completing several past missions that each had a customized spacecraft bus. Additional effort was placed into improving the bus' robustness and reliability to a level that has yet to be realized on CubeSats. Redundant components and software algorithms are utilized to ensure system functionality in the event of a component failure. The spacecraft bus has also been developed with the university engineering and research environment in mind. The student-built system's reliability and integrity is developed over the course of many tests, rigorous quality assurance processes, and through the use of heritage flight components. The redundancy and system integration architecture offers an unmatched 98% reliability value for one year missions; this is a 22% increase over typical single-string architectures. Each payload accommodated and each mission flown will add to the bus' heritage as approximately 95% of the spacecraft bus hardware is common between missions. For these reasons, the TECHBus is a novel system that is unique in the current CubeSat bus market, and will provide a powerful platform for space systems research and education at Georgia Tech's Space Systems Design Lab.