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 poster 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 are carried out to resolve chemical reactions and byproducts for Aluminum – a typical satellite structure constituent – under reentry conditions. MD simulation results are used to estimate the presence of oxides and predict the accumulated increase of reentry byproducts in the mesosphere when compared with that from meteoroids entering atmosphere and other natural sources. A methodology to estimate the residence time of these substances in the atmosphere is also presented so as to evaluate the polluting potential of mega-constellations reentry events.