ESA astronaut Alexander Gerst has spent over 5700 sunrises and sunsets in space, yet he has never been more than a day in the total darkness of a cave on Earth.

“I have been to several caves for small trips, but I haven’t really spent a long time in them. One very special thing that I have seen are the ice caves of Mount Erebus in Antarctica,” Alexander says.

Geophysicist, volcanologist and more recently International Space Station commander, Alexander is looking forward to adding more skills and knowledge to his tool set for space exploration with the new CAVES 2019 astronaut training course.

Follow his cave adventure on the CAVES blog.

Orbital sunrise from the International Space Station. Credits: ESA – A. Gerst