Performance Characterization of the Free Molecule Micro-Resistojet Utilizing Water Propellant (Postprint)

Advances in micro-technology manufacturing and capability have led to an increased interest in micro and nanosatellites. A propulsion system has been designed to meet the on-orbit attitude control requirements for nanospacecraft. The Free Molecule Micro-Resistojet (FMMR), a low cost, low power, high propellant storage density, and green propulsion system, has been analyzed in this study to determine its ability to provide a slew maneuver for a typical 10 kg nanosatellite. Additionally, a FMMR technology demonstrator (TD) has been fabricated using traditional and Microelectromechanical Systems (MEMS) techniques. The TD has been analyzed and tested in this study to determine its performance characteristics while operating with water propellant. Experimental data shows that the FMMR, with a heated wall temperature of 580 K, can attain a specific impulse of 79.2 seconds with a thrust level of 129 micro-N. For a given mass flow, higher thrust levels can be achieved by increasing the temperature of the FMMR heater chip. The experimental results agree favorably with predicted values from kinetic theory. Applying the measured performance of the TD to an optimized setup, the FMMR system could provide a 45-degree slew of a typical nanosatellite in 60 seconds, which is acceptable for many nanosatellite applications.
Presented at the AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit (43rd) in Cincinnati, OH on 8-11Jul 2007. Published in proceedings of the same as paper AIAA 2007-5185.