Micronewton Cold Gas Thruster Based on Silicon-Etched Two-Dimensional Nozzles

Abstract

The micronewton thruster is one of the essential technologies for providing an ultrastable satellite platform for scientific experiments in space. Particularly, space gravitational wave detection requires a microthruster with continuously adjustable thrust, high resolution, low noise, and fast response. To meet these requirements, we designed a two-dimensional (2D) nozzle and manufactured it using micro-electro-mechanical systems (MEMS). Compared to the nozzles machined with conventional methods, the nozzles etched by the MEMS can easily reach a micron size and form arrays to create mutual backups and also provide a way to widen the thrust range by switching the number of openings. Based on a single 2D nozzle, a cold gas microthruster prototype is constructed with nitrogen gas as the propellant. The thrust of the prototype is tested by a pendulum, the range can span 0–156 μN, the thrust resolution is better than 0.1 μN, and the thrust noise reaches 0.1 μN/Hz1/2 at 0.1 Hz. The result demonstrates that the scheme has the potential to be applied to gravitational wave detection missions.