High-Performance Warm-Gas Thrusters for Micro/Nanosatellites

The current push to develop small satellites, referred to as microsatellites (<100 kg) and nanosatellites (<10 kg), has resulted in the need to miniaturize several key technologies, including the propulsion system. Trade studies have been performed for these small satellites, and optimization of the propulsion system with respect to mass shows that cold-gas systems will result in the lowest overall system mass despite their low specific impulse. One way to improve the overall performance of a cold-gas propulsion system without suffering a weight penalty is to use Tridyney instead of helium or nitrogen cold gas. Tridyne, a non-explosive mixture of nitrogen (or helium), hydrogen, and oxygen, offers a 20-28% increase in specific impulse over nitrogen. The limitation of Tridyne for small satellites is that the particle size of commonly used granular catalysts is unsuitably large for use in a micronewton thruster. Coarse particles will result in propellant channeling with little reaction taking place, and a loss of performance. In this project, Ultramet proposes to build upon its experience with monolithic catalyst beds and develop a small, low pressure drop, monolithic catalyst bed optimized for use with Tridyne.