Iodine Electric Propulsion System Thrust Validation: From Numerical Modeling to In-Space Testing

Abstract

In this paper, we complete a full-thrust audit of an iodine-based gridded ion thruster. Prior results have demonstrated excellent agreement between indirect and direct laboratory thrust estimates. Here, thrust estimates from numerical modeling, indirect laboratory testing from diagnostic probes and propulsion system telemetry, indirect in-space testing from onboard propulsion system telemetry, and direct in-space testing by analyzing orbital maneuvers are compared to demonstrate consistency between the four methods and complete the thrust audit. Results from recent in-space testing of the iodine-based thruster demonstrate that thrust estimates from all four methods agree to within three standard deviations of uncertainty for the 11 maneuvers studied. This thrust audit represents a critical step toward improving the understanding and technological maturity of iodine-based gridded ion thrusters for future mission applications, and it demonstrates the utility of recently developed in-space thrust inference techniques for analyzing low-thrust maneuvers.