Speaker
Description
As space activities expand, it becomes increasingly important to assess and mitigate its environmental impact. This study focuses on the environmental impact of in-space propulsion systems, specifically examining the ground-phase life cycle from propellant production to integration into the launcher (cradle-to-gate). Four liquid bipropellant systems representing current trends and future directions are analyzed: MON-3/MMH, 98%-HTP/RP-1, 98%-HTP/Ethanol, and N2O/Ethane. The life cycle analysis identified significant environmental impact hotspots, particularly during the production phase of MMH, due to its energy-intensive distillation and specialized manufacturing processes. MON-3/MMH systems exhibit the highest overall environmental impact up to the propellant loading phase, driven by stringent fueling and decontamination requirements. The study also evaluates the system-wide environmental impact, considering both the propulsion system components and their performance in specific mission scenarios. Despite its specific impulse advantage, the MON-3/MMH combination emerges as the most environmentally impactful at system level, while N2O/Ethane is the least impactful. Interestingly, if only Global Warming Potential were considered, N2O/Ethane would rank second due to the ozone impact of N2O gas. This highlights the importance of a global life cycle assessment, summarizing environmental impacts into a single score that reflects the mission's objectives and priorities. Additionally, the study highlights that tank production, especially when using titanium, is a significant environmental hotspot in dry propulsion architectures. Even in wet architectures, which include the propellants in the analysis, tank production remains the primary contributor to environmental impact, accounting for over two-thirds of the total footprint.
