This public lecture was held on Wednesday, November 15, 2023 in Schwartz Auditorium, Rockefeller Hall by Prof. John Foster, University of Michigan.
High power electric propulsion and nuclear propulsion systems offer the promise of liberating humans from low Earth orbit and enabling quick trip times throughout the solar system. But how do we practically test these engines on the ground? The energetic plumes these rockets produce interact with the walls of vacuum chambers which are supposed to simulate space-like conditions, leading to high backsputter rates and elevated chamber pressure. If these problems are unavoidable, how do we account for these processes when interpreting the test data and then extrapolating to space operation? In this talk, we survey the challenge to testing high power electric propulsion on the ground using the gridded ion thruster as an example, unpacking the myriad of physical processes that can impact interpretation of on-orbit performance. We also survey past ground test methods of characterizing nuclear thermal rockets—which are prohibited today—and current approaches being posed to test, understand, and characterize performance of these engines on the ground.