ABSTRACT: A vibrant in-space economy requires advanced propulsion systems capable of operating on novel propellants. Electric propulsion provides lower thrust but higher fuel economy than chemical propulsion systems. This technology supports human presence in space by enabling operations such as deploying satellites from extraterrestrial bodies for continued support of ground operation or station-keeping for in-space habitats. Implementing in-situ resource utilization (ISRU) is one way to ensure sustainability in these missions. However, adapting electric propulsion systems to the complex molecular propellants available in the space environment is difficult because thrusters historically have lower efficiencies and cathodes have material compatibility challenges. To address this, we first draw a comparison between two more conventional gases: xenon and krypton. We discuss how we can use lessons learned from this comparison and interdisciplinary techniques to approach more complex propellants and other challenges within the field of electric propulsion.

Dr. Leanne Su is a National Research Council postdoctoral fellow in the Spacecraft Engineering division at the Naval Research Laboratory working on Hall thruster and cathode operation with molecular propellants. She graduated from the University of Michigan’s Plasmadynamics and Electric Propulsion Laboratory in 2023, where her research focused on the performance of magnetically shielded Hall thrusters operating on krypton at high powers. Previously, she received her B.S. in Aeronautics and Astronautics as well as a minor in Diversity from the University of Washington. Dr. Su was an National Science Foundation and Amelia Earhart fellow, the lead author for the 2023 AIAA Electric Propulsion Best Paper, and the recipient of the William W. Willmarth Research Prize in Aerospace Engineering for Outstanding Experimental Ph.D. Outside of research, she has published a science-fiction novel and enjoys taking silly photos of her cat Pudge.