Greenhouse Gas (GHG) Emissions Poised to Rocket: Modeling the Environmental Impact of LEO Satellite Constellations

Abstract

The proliferation of satellite megaconstellations in low Earth orbit (LEO) represents a significant advancement in global broadband connectivity. However, the environmental impact, particularly greenhouse gas (GHG) emissions associated with these constellations, remains relatively underexplored. This study addresses a critical gap in modeling the GHG emissions of current and future satellite megaconstellations. To quantify the emissions, we employ a comprehensive open-source life cycle assessment (LCA) methodology to evaluate the environmental costs of producing, deploying, and maintaining satellites across various megaconstellations and launch vehicles. Our analysis reveals that the production of launch vehicles and propellant combustion during launch events contribute most significantly to overall GHG emissions, accounting for 72.6% of life cycle emissions. Among the rockets analyzed, reusable vehicles like Falcon-9 and Starship demonstrate 95.4% lower production emissions compared to non-reusable alternatives, highlighting the environmental benefits of reusability in space technology. The analysis also includes a per-subscriber emissions evaluation for each megaconstellation, which reveals substantial variation – with some constellations, such as Globalstar, exhibiting emissions per subscriber exceeding the average by over 375%. These findings underscore the importance of judicious selection of launch vehicles and satellite designs to minimize environmental impact. This study provides a critical baseline for policymakers and industry stakeholders to develop strategies for reducing the carbon footprint of satellite megaconstellations, thereby promoting sustainable growth in the space industry. Our code is available in the Open-source Rocket and Constellation Lifecycle Emissions (ORACLE) repository, allowing for transparency and facilitating further research in this field.