Feasibility Study of Laser-Fabricated Micro-Needles as an Electrospray Thruster

Capable of carrying small-scale instruments, micro-satellites, often called CubeSats for their shape, provide an excellent platform for a variety of educational and research missions. However, once placed in orbit satellites experience small amounts of drag that slow the craft down, and deteriorate its orbit over time. The addition of a propulsion system will allow a CubeSat to correct and maintain orbit, as well as perform other maneuvers. Due to their size and power requirements, CubeSats cannot accommodate conventional propulsion methods. Instead, these satellites rely on electric propulsion to provide a compact, low power thruster for making orbital adjustments. Of particular interest to this research are electrospray thrusters. Because of their size, electrospray thrusters can easily be clustered together to form large arrays to make up for the small amounts of thrust, making them ideal for CubeSats.Microfabrication techniques developed at UTSI allow preparation of arrays of emitters suitable for electrospray applications, and exhibiting critical dimensions that can potentially enable smaller, denser arrays requiring less space and power. In this work, these needles were modeled and simulated under an applied voltage to determine if they can be used as electric field enhancers in a thruster. Using procedures established from references, the optimal emitter spacing was also determined.