Slit Colloid Thrusters Using Ionic Liquid Propellants

Currently there are no efficient electric propulsion engines performing in the milli-Newton thrust range, a capability needed for primary and ACS microsatellite propulsion. We propose to develop a slit colloid thrusters using ionic liquids as propellant,which will fill this propulsive niche. We anticipate the following propulsive parameters: a thrust per slit colloid thruster of the order of 1 mN, a propulsive efficiency of the order of 70%, and a specific impulse of approximately 1000 sec.The choice of ionic liquids as propellants is essential for the proposed effort. Their general properties (mainly negligible vapor pressure and large electrical conductivity) make them the propellant of choice for colloid thrusters. The large variety ofionic liquids that we can choose from will make it possible to optimize the thruster, and achieve the propulsive parameter goals above mentioned. Alternatively, if the choice of ionic liquid were restricted to a list with unique properties, theelectrospraying of the candidates can be engineered to achieve the propulsive goals. This family of microthruster will fulfill the primary and ACS propulsion required by micro/nanosatellites. Their performance (especific impulse and efficiency) will be superior to that of its immediate competitor, the FEEPs developed in Europe. Slitcolloid thrusters will enable the expected proliferation of clusters and constellations of micro/nano-satellites for communications, surveillance and aggressive science missions.