MEMS Colloid Thruster Array

Colloid thruster technology continues to be attractive for spacecraft propulsion, especially since its specific impulse can be many times greater than even the best bi-propellant chemical rocket. However, the technology was abandoned in the 1970s due to low charge-to-mass ratios, which lead to excessively high voltages and large inert mass fractions. The recent advent of microelectromechanical systems (MEMS) technology and improved propellants has created renewed interest. Colloid thruster arrays may produce large thrust levels, while maintaining the ability to deliver a small impulse bit from a single emitter, making them well suited to micro- and nanosatellites. However, a number of technological barriers have prevented full development at the micro-scale. In particular, simple fabrication strategies are needed to create dense two-dimensional thruster arrays. Therefore, TDA Research, Inc. and the University of Colorado at Boulder propose a MEMS-based colloid thruster array concept that is manufacturable. In Phase I we designed, built and tested a MEMS colloid emitter that can be replicated on the same chip to build up a two-dimensional thruster array. In Phase II we will improve upon our design, increase the array packaging density, and demonstrate thrust modulation from individually addressable 2D colloid thruster arrays.