Radiated Emissions and Magnetic Field Characterization of a 2-kW Electrothermal Propulsion System

Earth-orbiting spacecraft that include increasingly sensitive telecommunications, Earth-observing/sensing, and/or scientific instrument payloads often utilize electric propulsion systems. Such systems can generate high levels of radiated and conducted electromagnetic interference (EMI) making the accurate characterization of propulsion system EMI critical to spacecraft design. Radiated emissions and magnetic field measurements were performed on a 2-kW hydrazine arcjet electrothermal propulsion engine at the Large Dielectric Pulsed Propulsion facility at the Princeton University Electric Propulsion and Plasma Dynamics Laboratory. Plume/thruster emissions were characterized during steady state and transient startup operating conditions per MIL-STD-461E method RE102 over the 200-MHz to 18-GHz frequency range while magnetic field measurements were performed per MIL-STD-461E method RE101 from dc to 100 kHz. Results demonstrated a high level of compatibility between the arcjet electrothermal propulsion system with even the most sensitive radio- frequency payloads or science instruments to levels of -8 dBldrmuV/m and below.