Understanding the Atmospheric Effects of Spacecraft Re-entry

As part of ESA’s Green Agenda, the Agency is committed to driving the design of space products and services towards minimising environmental impacts across their entire life cycle. With the rapidly increasing frequency of satellite launches and spacecraft re-entries, robust assessment of their atmospheric and environmental consequences has become a critical scientific priority.

This presentation emphasises the importance of acquiring real-world observational data and advancing our understanding of the chemical and physical processes associated with spacecraft launch and re-entry emissions. Recent studies indicate that anthropogenic metal emissions from spacecraft re-entry may become a significant contributor to the stratospheric particle burden, in some cases approaching the natural meteoritic influx for specific elements. Observations from high-altitude aircraft and ground-based facilities have already identified metal-rich aerosols in the stratosphere, raising concerns regarding their roles in cloud formation, radiative forcing, ozone depletion, and broader atmospheric chemistry.

The presentation addresses key scientific, engineering, and environmental challenges related to spacecraft launch and re-entry, including the initiatives of the Atmospheric Impacts of Re-entry and Launch (AIRL) working group, ESA’s targeted measurement campaigns, and ongoing and future research opportunities. It highlights the need for coordinated, cross-disciplinary approaches that integrate observations, laboratory studies, and modelling. As space activities continue to accelerate, sustained upper-atmosphere research and science-driven policy development are increasingly essential. This presentation highlights ESA’s initiatives in responding to these challenges, reinforcing the need of atmospheric impact assessment in shaping the future of sustainable space operations.