MEMS Colloid Thruster Array

Colloid thruster technology continues to be attractive for spacecraft propulsion, 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 nano-satellites. 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., teamed with the University of Colorado at Boulder, proposes a fundamentally sound MEMS-based colloid thruster array concept that we have the facilities and experience to build. In Phase I we will design and fabricate 2D colloid thruster arrays, determine their susceptibility to voltage breakdown and balance the flow through individual thrusters. In Phase II we will integrate these technologies to demonstrate thrust modulation from individually addressable 2D colloid thruster arrays.