Variable Thrust/Specific Impulse Electrospray Propulsion

ABSTRACT: Future Department of Defense space missions require precise, fine-positioning capabilities combined with large maneuvrability requirements. The purpose of this STTR is to: a) identify propellants for electrospray propulsion able to cover, at high propulsion efficiency, an unusually wide range of specific impulses, from several hundred seconds, typical today of colloidal propulsion up to values of thousands of seconds, typical today of only purely ionic propulsion; and b) meet thrust requirements by microfabricated multiplexed electrosprays. The challenge will be met with a fixed thruster and propellant. No electrostatic ion thruster based on ions of fixed mass/charge is suitable to span such a wide specific impulse range at high propulsion efficiency and full power. Electrospray propulsion, on the other hand, has this useful characteristic, since it admits a wide range of mass/charge values at relatively constant beam power. One can therefore use the full power available over the whole range of specific impulse with a single propellant. This STTR collaboration aims to validate this exciting new approach to micro-electric propulsion for military and civilian nano-satellite applications, capitalizing on the unique combination of expertise of the Yale-AASC team. BENEFIT: This project will develop innovative, on orbit propulsion methods that provide variable high thrust and high specific impulse at high efficiency, and enable system orbit agility or new orbit regimes. The high efficiency over an unprecedented range of specific impulse makes the electrospray micro-thruster a key enabling technology for all future nano-satellites.