A look back at the Under Antarctica Expedition

Find out how the adventure unfurled for this extraordinary expedition in Antarctica, supported by Val d’Isère.

News | 21 January 2026

South Pole of Inaccessibility

After 42 days of expedition and almost 1,800 km travelled since setting off on 3 November 2025, Heïdi Sevestre and Matthieu Tordeur reached the South Pole of Inaccessibility, one of the most remote places on Earth and the point in Antarctica furthest from any coastline.

This milestone marked a major stage in the Under Antarctica Expedition. It was the fifth expedition in the world and the first from France to reach the site by kite-ski. To our knowledge, Heïdi Sevestre was also the first woman to reach the Soviet South Pole of Inaccessibility by this means of travel. The site had last been visited by humans in 2023, when it was reached by aircraft..

On site, the scientists were able to deploy their radar around the former Soviet station, now buried under the ice, to gain a better understanding of what lies beneath. A valuable step forward for polar research and our understanding of glacial dynamics.

Geographical South Pole

After reaching the Geographical South Pole, the iconic point marking the Earth’s axis of rotation, Heïdi Sevestre and Matthieu Tordeur continued their journey across the Antarctic continent. There, they carried out further scientific measurements before embarking on the final leg of the expedition towards Hercules Inlet, where their journey ended.

Conditions proved particularly demanding on this final stretch: heavily overcast skies, difficulties recharging the scientific equipment and communications that were sometimes interrupted. Despite these challenges, the team was able to redeploy the deep-penetrating radar, reaching depths of up to 110 metres, to image the ice’s inner layers and map the bedrock beneath the Antarctic ice sheet.

End of the journey Hercules Inlet

After reaching the Geographical South Pole, Heïdi Sevestre and Matthieu Tordeur began the final stage of their crossing. Conditions became increasingly challenging, with strong winds and a hard-packed icy surface, making progress difficult right through to the final kilometres. On several occasions, they had to adapt their route, at times taking shelter in their tent until the weather eased.

As they approached the Antarctic coast, the Ellsworth Mountains appeared on the horizon, signalling that the expedition was nearing its end. Reaching Hercules Inlet, on the Filchner-Ronne Ice Shelf, proved challenging due to the many crevasses. On the last day of their journey, despite extreme caution and unpredictable winds, the two explorers covered the final kilometres on skis, pulling their pulkas behind them.

At 8.50pm (French time) on 21 January 2026, after 80 days of expedition and 4,000 km covered, they reached Hercules Inlet. Under Antarctica became the first French crossing of the Antarctic interior by kite-ski, and the first kite-skiing expedition dedicated to polar science.