Development of Green Monopropellant Micro-Thruster

This paper proposes the preliminary design of a 1-N class monopropellant micro-thruster for sustainable in-space propulsion. The thruster employs High Test Peroxide (HTP) with an 87.5% concentration, an environmentally benign alternative to conventional hydrazine-based chemical propulsion systems. The design incorporates a silver gauze mesh-type catalyst bed design that is used to thermally decompose hydrogen peroxide propellant. Hydrazine-based chemical systems pose environmental and safety-related concerns due to high levels of toxicity. To ensure safe handling and reduced environmental impact, hydrogen peroxide has much reduced toxicity, and thus is a more environmentally responsible choice. This green propulsion technology offers facility-related cost advantages due to reduced safety protocols and requirements for handling and infrastructure associated with use of a green propellant. It aims to reduce the environmental footprint of space activities while maintaining or improving performance, therefore it is in line with the UAE's 2030 Green Agenda and Sustainability Development Goals. In addition, such safe technology fosters international cooperation in sustainable space exploration due to adherence to global environmental standards and being compliant to International Traffic in Arms Regulations (ITAR) compliant. The in-space propulsion capabilities of this thruster enable a wide range of applications, including orbital manoeuvres, attitude control, trajectory corrections, proximity operations, and spacecraft landings. The theoretical specific impulse performance of the proposed design is 180 sec in vacuum. The development of miniaturized chemical thrusters poses challenges in manufacturing and testing due to the significantly reduced scale. This paper addresses these challenges and emphasizes their significance in advancing the research's next stages.