Given no path, a group of explorers makes their own way through a cave. While one scouts ahead, others survey the area and map their progress.

The demanding exercise is part of the outdoor and technical lectures five ‘cavenauts’ are receiving from ESA’s CAVES training before they head off to explore independently a cave system in the Italian Apennines. They are learning new skills and work safely as a team in an alien environment, as if on a risky space expedition.

Rope climbing is one of the skills the trainees must master to climb, descend and move across uneven terrain. Like during a spacewalk, they get to grips with the tethers to stay securely attached at all times, their view narrowed to what headlamps can reach in total darkness. They tackle vertical drops of up to 35 metres, with rope re-belays of 20 metres maximum.

Participants of the eighth edition are ESA astronaut Rosemary Coogan – pictured here in the foreground – member of ESA’s astronaut reserve and the Fly! project John McFall, NASA astronaut Tracy Dyson, NASA astronaut candidate Ben Bailey, and JAXA’s Ayu Yoneda.

While learning to be safe on a rope, each trainee has to think about how to fulfil a role: commander, lead of the scouting or survey team, or the person responsible for logistics at the campsite. Every participant has a role, rules and goals to follow. From day one, they build their team and grow together.

For two intense weeks, this multinational and diverse group of fast learners experiences the psychological extremes of real exploration to become better spacefarers. The training encourages them to stay curious and autonomous.

CAVES is consistently rated by astronauts as one of the best experiences to help prepare astronauts for spaceflight. ESA is the only space agency to offer this type of training.

Similarities with spaceflight abound: isolation, strict EVA-like tether procedures and safety protocols, limited supplies and scientific research tasks are all part of the mission. The trainees learn mapping and surveying techniques, as well as the art of underground photography to document their journey.

Other analogies with spaceflight include constant situational awareness, effective communication with the ground – only twice a day – and making complex decisions.

After completing the first leg of the training, it’s time for them to take full ownership of the expedition. From today and for four days, they will live and work together in a pitch-black cave, cut off from the outside world. Each will hold a role that swaps halfway through.

The path they choose will shape their growth as space travellers and as a team.

Follow their expedition on our CAVES Flickr gallery and on ESA’s social media platforms.