Variable Thrust/Specific Impulse Electrospray Propulsion

Yale University and Alameda Applied Sciences Corporation (AASC) propose to develop a single propellant electrospray micro-thruster for space propulsion with a wide specific impulse range, from 500s at the low end to >2500s, with the goal of 10,000s, while maximizing the performance. Three key prior accomplishments have motivated the formation of this team: Yale, working with ARL has demonstrated MEMS fabricated electrospray arrays at atmospheric pressure; Yale has deep expertise on single-emitter electrosprays with the capability to vary mass/charge of droplets, an essential feature of our continuously variable Isp approach; AASC has expertise gained from a DARPA funded effort to develop MEMS arrays of liquid metal ion tips, designed for 500s-10,000s Isp. Here we seek to combine this past experience to validate, at TRL3 in Phase I, an innovative approach to a single propellant/single thruster architecture for small satellite nano- and micro-propulsion. Our approach will use two-dimensional (2D) multiplexed arrays of electrospray sources to span a wide range of specific impulses from 500s up to at least 2500s (extendable to 10,000s in Ph II). The full range of variable Isp will be achieved by changing the mass/charge of the drops, while maintaining full power. BENEFIT: Future Department of Defense (DoD) space missions require precise, fine-positioning capabilities combined with large maneuverability requirements. This project will develop innovative, on orbit propulsion methods that provide variable high thrust and high ISP at high efficiency, that enable system orbit agility or new orbit regimes.)