Preliminary Design of a Propellant Feed System for the µSTAMPS Thruster

CubeSats offer a low-cost, modular platform for space missions, but their capabilities remain constrained by limited propulsion options. The µSTAMPS micro-thruster, a compact electrospray propulsion device designed for CubeSats, is further limited in operational constraints by its minimal internal propellant reservoir. To overcome this limitation, a scalable and autonomous Propellant Feed System (PFS) has been developed to extend mission lifetimes and support more ambitious maneuvers. The PFS features a capacitance-based sensor for real-time fluid-level monitoring and an Arduino-based control circuit to autonomously regulate propellant delivery. Experimental validation confirmed accurate sensing, reliable pump functionality, and effective autonomous control. Challenges such as fluid routing complexity and minor electrical inconsistencies were addressed through iterative refinement. This work demonstrates a key advancement toward long-duration, self-regulating propulsion systems suitable for future CubeSat applications.