Date of Award

3-14-2014

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Aeronautics and Astronautics

First Advisor

Alan L. Jennings, PhD.

Abstract

The objective of this research is to explore the technical soundness of a very large, cross-shaped, parabolic, sparse aperture antenna extending 75 m from the bus. Specifically, describing the environment of the satellite, the effect of fabrication error on the structure and the remaining error budget for the system. The methodology involves creation of an ideal truss structure, to which all others are compared. A uniform distribution of proportional errors up to 1e-5 is introduced into the truss members' lengths and the models are subjected to a static Finite Element Analysis. A solution for the surface normal error is addressed using Lagrange multipliers. The goal is to hold the surface normal error for the entire satellite below a root mean square of 15 mm. The analysis yields a surface error of less than 1.53 mm, well within requirements. Despite the enormous size of the antenna reflector, and tight diameter/surface error ratio of 10,000 required for L-band communication, the system seems feasible. The values achieved for truss induced surface errors are in line with established techniques for analyzing full aperture, and strip, mesh antennas. With the mesh reflector and truss largely defined, nearly half of the 15 mm error budget remains.

AFIT Designator

AFIT-ENY-14-M-24

DTIC Accession Number

ADA598927

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