3/4/2025 Debra Levey Larson
Written by Debra Levey Larson
Ally Leeming spent her high school and undergraduate years with one foot in science and the other in the arts. Now, as one of Joshua Rovey’s Ph.D. students in the Department of Aerospace Engineering in The Grainger College of Engineering, University of Illinois Urbana-Champaign, both feet are firmly planted in electric propulsion.
Leeming holds a National Science Foundation Graduate Student Research Program Fellowship and has already participated in two unique programs. She was a summer intern at the U.S. Naval Research Laboratory in Washington, D.C. and was one of 17 Ph.D. students working with NASA’s Jet Propulsion Lab on a project in the Planetary Science Mission Design School.
“For the NRL internship, I was an independent researcher in their spacecraft electric propulsion division,” Leeming said. “They set me loose on the first day, giving me access to their electric propulsion sources.”
Over that summer, she developed and deployed a novel catalytic probe technique to measure neutral density in electric propulsion radio frequency plasma sources.
“Being able to accurately measure neutral density in EP devices is crucial because it directly relates to the ionization efficiency of a thruster. Neutrals are not ionized and provide thrust to the spacecraft. If you have high neutral density, you’ll have a ow ionization efficiency and so low performance. Neutrals also affect the thruster’s lifetime—which is what we are trying to predict.”
Leeming said her experience at JPL was completely different.
“It was all planetary science, and I was the only pure aerospace engineer in the group of 17 Ph.D. students. We chose an objective from NASA’s decadal—a huge document NASA puts together every 10 years to identify areas that need research. We chose to design a mission to Ceres—a body between Earth and Jupiter—to investigate if there is a liquid ocean underneath the surface.”
Leeming’s role on the mission was to help design the entire power system for the spacecraft. She said the most exciting part of the process came during the final week of the program when the team met with JPL’s Team X.
“We were each assigned to a different subsystem on a spacecraft and paired with a mentor who is an expert in that field. During those first three days, we worked with Team X to design the spacecraft and left with a CAD model of it. It was so cool to see the mission we’d been dreaming about take shape.”
Reflecting on how she finally found her focus in the field of electric propulsion, Leeming described her early years in which she blended polar-opposite pursuits.
“My years in trumpet performance at the Las Vegas Academy of Arts were magical. But I reached my zenith, my peak as a musician and I didn’t want a lackluster career. I wanted to do something with my life that meant something. In my junior year of high school, I was trying to figure it out. If not music, what? I came across Carl Sagan's book The Demon-Haunted World and it changed my life. That's when I fell back in love with science.”
As an undergrad at Suffolk University in Boston, she continued to balance her interests as the president of both the jazz band and the Physics Society.
“On Fridays, I had jazz band then went straight to my physics meeting. In my sophomore year, at a physics conference, I went to a session on the physics of jazz, and I heard the worst jazz I've ever heard in my entire life. Maybe there’s an overlap, but if there is, I missed it.”
Leeming did find at least one overlap in her love for space science and the arts. Although her major as an undergrad was physics, her minor was creative writing, specifically poetry.
While at Suffolk, she won the Robert K. Johnson Poetry Prize. The title of her poem: “Falcon 9”.
“You can see where my true heart is,” she said.