Date of Award


Document Type


Degree Name

Master of Science in Astronautical Engineering


Department of Aeronautics and Astronautics

First Advisor

Carl R. Hartsfield, PhD


Secondary payloads, such as CubeSats, are being increasingly used by the US Department of Defense in the role of defense capability enhancement, and these increasingly complex defense missions can require extended lifespans that result in the need for a thruster. While many thruster options exist, characteristics such as propellant toxicity, complexity, and low performance limit many viable solutions. However, a potential answer that satisfies these thruster limitations is found in electrothermals, specifically the resistojet. The research presented here represents the first attempt to construct a 1U water-propellant resistojet thruster design and establish an initial characterization through evaluation of various performance values and design effects. This was achieved through assembly of additively-manufactured and commercial-off-the-shelf components, as well as construction and use of a vacuum chamber testing bed. This study revealed various inherent assembly risks and design flaws that resulted in the failure of the thruster to enter performance testing, yet heater block functionality was verified and heat loss experimental testing revealed how the design effects result in the propellant tank absorbing detrimental levels of heat over time. Still, due to the rapid function of the heater block, it was determined that this would not pose an operational issue in the future.

AFIT Designator


DTIC Accession Number