Rocket launches and re-entry of reusable and discarded objects adds anthropogenic trace gases and aerosols to almost all layers of the atmosphere. The space sector is the only anthropogenic emission source to the middle-to-upper atmospheres where pollutants can persist for decades, leaving a lasting legacy of atmospheric pollution. These pollutants are becoming increasingly ubiquitous due to the recent exponential growth of the space sector, yet there are no regulatory controls targeting these emissions. Quantification of the complex and unique effects on the atmosphere is mired by many uncertainties and data gaps, such as in the chemical composition of exhaust from novel propellants, the resultant evolution during plume afterburning, the locations and trajectories of launches and re-entry, the radiative and chemical kinetic properties of the pollutants, and the physics and chemistry of controlled or uncontrolled re-entry, ablation, and breakup. Meanwhile a lack of openly-available modelling tools is compounded by a scarcity of real-world experiments and observations, and both historical and future impact estimates are hindered by a lack of commercial space activity data or well-supported growth projections. This session invites submissions from all EGU disciplines by representatives in and beyond academia to share planned, current, or ongoing research that provides new knowledge in this area, explores new open-source modelling techniques, or exposes methodological gaps that need to be resolved to inform policies and for a truer determination of the influence of space activity on the atmosphere. We are also interested in innovative methods adopted by researchers focusing on volcanic emissions, geoengineering, and meteors that could be applied to the space sector.