Current technology makes it possible to explore the various 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 the universe. Likewise, space probes have enabled us to discover thousands of exoplanets—distant extraterrestrial worlds that could harbor life and of which there is still so much to learn.

But how can humans explore the extreme environments of our planet, in water and in the air? What techniques are used to probe extraterrestrial worlds and search for the origins of life? And what do space missions, technical diving, and parachuting have in common?

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.

5:30pm  Doors open
6:00pm  Welcome address – Leïla Ojjeh, Director, EPFL Alumni
6:05pm  Introduction – Claude Nicollier, Astronaut, Honorary Professor, EPFL
6:15pm  Campus Lecture by Gaëlle Giesen: “A Life of Exploration Between Stars, Skies, and Abysses”
6:55pm  Q&A session
7:15pm  Networking aperitif
8:00pm  End of the event