Thomas C. Co

Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)


Department of Aeronautics and Astronautics

First Advisor

Jonathan T. Black, PhD.


A desirable space asset is responsive and flexible to mission requirements, low-cost, and easy to acquire. Highly-efficient electric thrusters have been considered a viable technology to provide these characteristics; however, it has been plagued by limitations and challenges such that operational implementation has been severely limited. The technology is constantly improving, but even with current electric propulsion, a spacecraft is capable of maneuvering consistently and repeatedly in low-Earth orbit to provide a responsive and flexible system. This research develops the necessary algorithm and tools to demonstrate that EP systems can maneuver significantly in a timely fashion to overfly any target within the satellite’s coverage area. An in-depth analysis of a reconnaissance mission reveals the potential the proposed spacecraft holds in today’s competitive, congested, and contested environment. Using Space Mission Analysis and Design concepts along with the developed algorithm, an observation mission is designed for three conventional methods and compared to the proposed responsive system. Analysis strongly supports that such a spacecraft is capable of reliable target overflight at the same cost as non-maneuvering ones, while it is three times as responsive in terms of time-to-overflight by sacrificing one third of its mission life. An electric versus a chemical system can maneuver 5.3 times more. Its responsiveness and mission life are slightly inferior to that of a Walker constellation, but cuts total system cost by almost 70%.

AFIT Designator


DTIC Accession Number