NASA is continuing its development of electric propulsion engines for various applications. Efforts have been directed toward both large and small thrusters, depending on the end use. A current program is focused on the development of a miniature thruster. Development of a Miniature Xenon Ion (MiXI) thruster will enable precision spacecraft positioning and formation maneuvers for formation-flying spacecraft. The current MiXI thruster prototype will provide 0.5 3 mN thrust at 3000 sec specific impulse and efficiencies around 50% or better. The MiXI thruster will use Xenon propellant, a noble gas, minimizing spacecraft contamination. One of the challenges of such a thruster is to be able to accurately control the flow of propellant. The required flow rates are on the order of 0.1 sccm of Xenon. To this end Midé proposes to develop a small flow control valve based on piezoelectric technology. Midé is a world leader in this technology, demonstrated by its existing patented packaged actuator product line and past valve experience. Aerojet will provide electric propulsion expertise for the duration of the program and serve as a technology integration and transition path.