Campus Lecture by Gaëlle Giesen “A Life of Exploration Between Stars, Skies, and Abysses”

On 26 February, the EPFL community gathered at the Rolex Forum to welcome Gaëlle Giesen, engineer at CNES, expert in space exploration missions, high-level diver and parachutist and Alumni Award 2025, for a campus lecture on “A Life of Exploration Between Stars, Skies, and Abysses”.

An EPFL physics graduate, Gaëlle Giesen earned a doctorate in astrophysics at the French Alternative Energies and Atomic Energy Commission (CEA) in Saclay, before joining the French space agency CNES in 2018. She has contributed to major missions such as Dragonfly, aimed at exploring Saturn’s moon Titan, and Ariel, focused on the atmospheric study of exoplanets. Alongside her scientific career, she has pursued high-level training in formation skydiving and technical diving—two passions she discovered during her time at EPFL. She has won several national titles in team skydiving, along with a World Cup and four runner-up finishes at the World Championships. In 2024, she set the women’s world record for deepest open-sea dive using a rebreather, reaching 222 metres. In 2025, she won the gold medal at the Women's 4-way Formation Skydiving World Cup and set the women's world record for deep cave diving with a rebreather, reaching a depth of 230 meters. Her unique path reflects a deep scientific curiosity and a continuous drive to push boundaries.

During this conference, Gaëlle Giesen discussed how current technology allows us to explore the different environments of our planet, from high altitudes to the depths of the ocean, as well as the celestial bodies of our solar system, in order to unravel the greatest mysteries of our universe. Similarly, space probes have enabled us to discover thousands of exoplanets, distant extraterrestrial worlds that could harbour life and about which there is still so much to discover.

Claude Nicollier, astronaut and honorary professor at EPFL, moderated the question and answer session that followed the lecture.

Thank you to Gaëlle for this enriching testimony and to everyone who contributed to the success of this Campus Lecture.