MS thesis abstract - Makins, Brian

Author:	Makins, Brian
Degree:	Masters of Science
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Interferometer Architecture Trade Studies for the Terrestrial Planet Finder Mission

A process, based on a quantitative systems engineering methodology, is developed and then used to conduct trade studies for NASA's Terrestrial Planet Finder (TPF) Mission. A software tool, which automates this process, was built to rapidly analyze competing system architectures, including the structurally connected (SCI), tethered spacecraft (TSI), and separated spacecraft interferometers (SSI). This tool, the TPF Mission Analysis Software (TMAS), consists of six macro-modules that take the top-level design variables; namely the number, size, and shape of the apertures, orbit of operation, interferometer baseline, and observational wavelength; and outputs a system design that best meets the mission requirements. Each macro-module consists of sub-modules which parametrically design the spacecraft subsystems. This approach provides many advantages, most notably, is the ability to refine the model components as the mission evolves. Ultimately, the designs are evaluated with the Generalized Information Network Analysis (GINA) performance module. GINA, uses the fundamentals of aperture physics, network theory, and accepted cost estimating relationships, to compute the metrics used to compare the architectures - the design's capability in each of TPF's operational modes, its cumulative performance in the presence of failures, and lifecycle cost. After TMAS was benchmarked, it was used to evaluate nearly 9000 different mission architectures. On the basis of the costperformance metrics, the relative advantages of the SCI, TSI, and SSI, as well as the toplevel design variables, were identified. The results provide insight into the trade space, which can be used to identify cost-effective architectures worth investigating in the latter design stages for TPF.