Professor Joshua Rovey is on a multi-institutional leadership team for a newly funded NASA Space and Technology Research Institute initiative. The project is entitled, the Joint Advanced Propulsion Institute. Rovey will lead the Diagnostics and Fundamental Studies team along with John Williams from Colorado State University. Rovey is a professor in the Department of Aerospace Engineering at the University of Illinois Urbana-Champaign and conducts innovative research in alternative fuel sources and electric propulsion.
“The reason this research is needed is because ground-based electric propulsion test facilities interact with operating thrusters, and then the data don’t represent in-space performance or lifetime,” Rovey said. “This includes elevated pressure from residual, inadequately pumped gas in the test facility, contaminants from the facility interacting with the thruster, and uncertain electrical paths through the thruster plume and the facility walls.”
Rovey explained that these effects become more pronounced as electric propulsion power increases. The higher mass flow rates lead to higher facility background densities. The higher energy flux promotes additional back-sputter, and the larger plumes and currents lead to more pronounced electrical effects. At high power, the impact of these interactions thruster operation and lifetime are poorly understood.
“The primary contribution from my team of researchers is to address the gaps in our understanding of these interactions,” Rovey said. “We will develop new diagnostics with well-characterized uncertainty in high-power thruster tests and conduct fundamental plasma-material interaction studies on surfaces with flight features. The measurements will enhance our understanding of the facility pressure effects, contamination, and electrical coupling. The fundamental studies will focus on the low-energy area of ion sputtering of materials and will characterize the carbon deposition processes using a novel carbon isotope tracking technique.”
The overall project seeks to enable the flight of high-power electric propulsion by creating physics-based limits, mitigation techniques, and extrapolation procedures to predict the in-space performance, operation, and lifetime of high-power electric propulsion devices from ground tests.
Additional Illinois participants include aerospace faculty members Huck Beng Chew and Deborah Levin.
NASA’s website states the goal of the Space Technology Research Institutes is to strengthen NASA’s ties to the academic community through long-term, sustained investment in research and technology development critical to NASA’s future. The investment from these research initiatives will also create, fortify, and nurture the talent base of highly skilled engineers, scientists, and technologists to improve America’s technological and economic competitiveness.
The director of JANUS is Mitchell Walker at the Georgia Institute of Technology. The co-director is Benjamin Jorns from the University of Michigan. The other team leads on the project are Richard Wirz from the University of California, Los Angeles: and John Williams from Colorado State University. Additional institutions participating are Penn State, Stanford, University of Colorado Boulder, Western Michigan University, Clark Atlanta University, Chicago State University, and the City College of Chicago.
NASA’s announcement was released on March 30, 2021.