Pulsed Plasma Thruster System for Microsatellites

The design and qualification of a pulsed plasma thruster (PPT) system for microsatellites is presented. Developed for the University of Washington's Dawgstar satellite, the micro-PPT provides formation keeping, orbit maintenance, and attitude control functions for satellites in the 10-100-kg range. Thrust is created when solid Teflon® propellant is ionized by a pulsed, high-current electrical arc and accelerated by a combination of electromagnetic and gas dynamic forces. The system presented provides thrust levels from 60 to 275 μN with specific impulses up to 266 s. A centralized power-processing unit utilizing high voltage switching enables a reduction in system mass when compared to previous designs. The total mass for the system presented is 4.20 kg, which enables control of three axes of rotation and two axes of translation. Approximately 1.7 million pulses were successfully accumulated on the flight qualification unit, representing a total system impulse of approximately 1000 N s. Mission design, mechanical and electrical design, and detailed results from ground testing are discussed.