Impacts of Satellite Reentry on Atmospheric Composition in the Era of Mega-Constellations: Molecular Dynamics Simulations

The number of orbiting satellites has increased significantly and in an unrestricted and unregulated manner in recent years. This trend is expected to continue with ongoing plans from the commercial space sector to build mega-constellations of microsatellites. However, the effect of satellite demise during reentry on Earth's atmosphere has only been lightly studied, and the long-term impact remains unknown.

This paper presents, to our knowledge, the first Reactive Force Field (ReaxFF) Molecular Dynamics (MD) simulation study on the atmospheric chemical mechanisms and byproducts generated by satellite reentry. Simulations will be carried out to investigate chemical reactions and byproducts for typical satellite surface materials under reentry conditions. MD simulation results will be combined with publicly available reentry forecasts to predict the accumulated increase of reentry byproducts in the mesosphere as a function of the number of reentering satellites. Such predictions will be compared with that from meteoroids entering atmosphere and other natural sources, and will be utilized to evaluate the polluting potential of mega-constellations in the atmosphere.