On 27 May 2025, in the framework of the Sustainability Series, a serie of conferences and roundtables organized by EPFL, the event on the topic « Towards a sustainable space: addressing the challenges of the final frontier” was the occasion to welcome Christophe Bonnal, expert in the field.
I had the pleasure to moderate the whole evening, among other things the roundtable with distinguished experts:
- Emmanuelle David, Executive Director, EPFL Space Center
- Christophe Bonnal, Space Debris and Launcher Expert, MaiaSpace
- Dr Susmita Mohanty, Director General, Spaceport SARABHAI
- Athanasios Nenes, Full Professor, Laboratory of Atmospheric Processes and their Impacts, EPFL
- Liesbeth Casier
Lead, Public Procurement and Sustainable Infrastructure and Coordinator of the NBI Global Resource Centre at the International Institute for Sustainable Development (IISD)
Watch the full replay:
The discussion was rich and intense on the following issues: « Anything that goes up will eventually come down… In the case of launchers and satellites in Low Earth Orbit, this means returning to Earth through an atmospheric reentry at very high velocity. This generates high heat fluxes, partially ‘melting’ the objects. Typically, about 20% survive reentry and pose a risk to people on the ground; however, the remaining 80% will stay in the upper atmosphere for some time, leading to unwanted disruptions to the ozone layer and contributing to greenhouse gas effects. How can we solve this dilemma – putting people at risk or damaging the atmosphere? »
Images of the evening (© Alain Herzog, EPFL):
