Demonstration of One Hundred Kilogram Xenon Throughput by a Low-Power Hall Thruster

The Hall thruster component of the Ascendant Sub-Kilowatt Transcelestial Electric Propulsion System (known ASTRAEUS) successfully demonstrated a propellant throughput of over 100 kg of xenon and demonstrated a total of 1.55 MN⋅s of impulse in a long-duration wear test. The thruster was operated for a total of 7205 h, with the test broken into five segments each with a different discharge power between 200 and 1350 W: 3291 h at 300 V/1000 W, 1739 h at 500 V/1000 W, 416 h at 400 V/600 W, 388 h at 200 V/200 W, and 1371 h at 300 V/1350 W. Telemetry and temperature measurements periodically recorded throughout the test revealed constant performance across each test segment and over the full test duration. Each segment was sufficiently long to obtain erosion rate data on the thruster by an optical profilometer. Subnominal magnetic field strengths were inadvertently applied to the thruster during the first 5 khr of the test due to an electrical ground-support equipment issue, which caused a downstream shift of the discharge plasma and higher erosion of the thruster’s pole covers than originally expected. This issue was corrected for the latter three test segments; however, the thruster performance and operational behavior at all reference operating conditions remained unaffected. The long-duration wear test was voluntarily terminated after the thruster processed 100.3 kg of xenon (Xe). This marks the world’s first long-duration wear test of a low-power magnetically shielded Hall thruster with a center-mounted hollow cathode wherein over 100 kg Xe throughput was demonstrated.