Modular EP Diagnostic Instrumentation Cluster (MEDIC)

ABSTRACT: The Modular EP Diagnostic Instrumentation Cluster (MEDIC) is a self-contained plasma diagnostic instrument suite uniquely suited to the task of characterizing and comparing thruster operation in ground test and on-orbit environments. Of paramount importance to the qualification of electric propulsion (EP) systems is the measurable influence of the ground testing and evaluation (T&E) facility background pressure and walls on the behavior and performance of electric thrusters. The complexity of these facility effects has prevented predictive models from extrapolating the measured performance of an electric thruster to in-space conditions. The discord between flight, ground T&E, and predictive modeling capabilities requires a novel state-of-health (SOH) diagnostic system that can monitor thruster behavior both in space and in different vacuum test chambers providing a direct comparison between the different environments. MEDIC accomplishes this task through the combination of advanced EP plasma diagnostics, such as high-speed (100 kHz) Langmuir probes, ion energy analyzers, and UV emission spectroscopy, with remote measurement capabilities - all within a self-contained 1U CubeSat unit. At the end of this program a fully operational MEDIC system will have been developed and characterized, and the measurement capabilities of MEDIC demonstrated on an operating xenon Hall thruster at multiple US facilities.; BENEFIT: A protoflight MEDIC system will be demonstrated and delivered to the Air Force with fast (up to 100 kHz) measurement capabilities, low power (15 year lifetime), and unprecedented versatility. This novel diagnostic will be capable of operating advanced plasma diagnostics in terrestrial T&E facilities and on-obit, thus giving the EP industry a critical tool to correlate in-flight and ground test data in support of thruster qualification. The in-situ measurements enabled by MEDIC may lead to much longer lived thrusters, accurate prediction of on-orbit capabilities, higher efficiency thruster systems, and on-orbit real-time monitoring of thruster behavior. In addition to providing a valuable tool for the EP industry, the low-cost, modular design of MEDIC gives it the flexibility to operate with a diverse array of plasma diagnostics that would be of interest to in-space scientific endeavors, such as characterization of Earths magnetosphere, the Heliosphere, and different planetary atmospheres.