Evaluation and Performance Optimization of a Hydrogen Peroxide-Based Green Monopropellant Thruster for Steady-State Operations

Hydrogen peroxide (High Test Peroxide, HTP) emerges as a promising candidate for green space propulsion applications due to its lower toxicity compared to liquid conventional propellants such as hydrazine and nitrogen tetroxide. This study aims to optimize the performance and reliability of HTP monopropellant thrusters, focusing on catalyst bed stability, efficiency, and durability during extended steady-state operations. Key parameters, including catalyst bed packing, pellet size, bed load, and HTP concentration, were investigated in this study for their impact on the steady-state performance, using the pressure loss across the catalyst bed as an indicator of catalyst deterioration. Results indicate that an optimal pressure drop of 1–1.5 bar across the catalyst bed provides optimal stability and durability. To evaluate transient characteristics, effects of bed load, HTP concentration, and pre-heating temperature on thruster response times were investigated. Following the optimization process, a lifetime test with an HTP throughput of 6 kg was conducted to monitor performance variations over time. Additionally, the blowdown characteristics of the thruster were analyzed to assess performance under end-of-life conditions. The experiments in this study demonstrate that HTP monopropellant thrusters are viable candidates for reliable space missions, particularly for long-duration operations such as station-keeping maneuvers.