Date of Award

Summer 8-2025

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Mechanical & Aerospace Engineering

Program/Concentration

Aerospace Engineering

Committee Director

Brett Newman

Committee Member

Krishnanand Kaipa

Committee Member

Oleksandr Kravchenko

Abstract

Rocket propulsion has been a primary focus for scientific and technical advancement supporting space exploration. For long-duration, low-thrust space missions, propulsion systems designed with plasma energy as the primary source for generating thrust are of high interest. Plasma energy, like electric propulsion, involves the excited state of ionized atoms, where the ionized particles are separated and then act as a propellant to push a spacecraft in the intended direction for flight. Although more energy efficient compared to traditional rocket systems, plasma propulsion has the deficiency of consistent erosion of the metallic containment substrate, as plasma is being generated and released for thrust. To lessen the impact of this deficiency by improved material reinforcement, research explores the use of nonmetal composites as a new containment substrate, along with improved geometry and wall properties of the thruster itself. Previous studies have shown that plasma erosion occurs in common electrical propulsion systems, such as the Hall Thruster, at consistent rates depending on the intensity of ion emission. On average, plasma thrusters can operate with a duration of 10,000 hours, but end up failing when the ability to generate thrust deteriorates due to advanced erosion. Because of this, plasma-ion thrusters have seen limited adoption in space missions, despite their reliability and higher specific impulse. The use of nonmetallic composite substrate appears to be a viable wallmaterial for plasma containment with lower erosion rates, because this material possesses physical properties such as toughness and low thermal conductivity to handle tremendously high temperatures and low thermal expansion to limit strain from temperature exposure. Furthermore, analysis using multiphysics modeling and numerical methods can reveal patterns concerning how plasma erosion affects certain components of the thruster. This information in turn can point to certain dimensions and wall characteristics of the thruster to optimally integrate the new substrate material that would potentially reduce plasma erosion and increase life for these thrusters during all ranges of mission operations. The anode walls of the plasma thruster are usually exposed to plasma at average temperatures of 1,000 K. Findings have shown that the new thruster design can withstand higher than average temperatures of plasma generation, all while displaying a more manageable plasma current density discharge.

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DOI

10.25777/f18a-qq03

ISBN

9798293841721

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