Development of a Monolithic Ceramic Electrostatic Ion Thruster for Interplanetary SmallSat Missions

This paper describes the design, fabrication and evaluation of a novel electrostatic thruster which was designed for deep-space missions. The thruster design attempts to achieve high-Isp, low-mass, low-volume, and long electrode lifetime by leveraging a novel materials system. The thruster uses the Low Temperature Co-Fired Ceramic (LTCC) materials system to realize a monolithic ceramic electrostatic RF ion thruster, or LTCC-ET. LTCC technology is analogous to PCB and entails laminating and co-firing layers of material containing conductive traces, vertical interconnects, and cavities. The design incorporates a propellant port, propellant manifold, plasma cavity, antenna, high-voltage electrodes. There are three major merits of using LTCC technology for the LTCC-ET. First, electrodes, which would typically be exposed to plasma in a conventional thruster, are embedded in durable ceramic, significantly increasing electrode lifetime. Second, the manufacturing process is scalable and low-cost; prototypes in single unit quantity cost ~$3500. Additionally the thruster is low mass (110 g), compact (72 mm X 72 mm X 8 mm), and can endure temperatures in excess of 900 C. Finally, the electrostatic thruster design renders the LTCC-ET capable of high Isp. Three prototypes have been fabricated at the University of Arkansas and were evaluated at NASA’s Marshall Space Flight Center