Credit: ESA-V.Crobu

Astronauts from five space agencies around the world are taking part in ESA's CAVES training course – Cooperative Adventure for Valuing and Exercising human behaviour and performance Skills.

The two-week course prepares to work safely and effectively in multicultural teams in an environment where safety is critical.

As they explore the of Sardinia they will encounter caverns, underground lakes and strange microscopic life. They are testing new technology and conducting science – just as if they were living on the International Space Station. The six astronauts relying on their own skills, teamwork and ground control to achieve their mission goals – the course is designed to foster effective communication, decision-making, problem-solving, leadership and team dynamics.

This year is the first international space cooperation to involve astronauts from China, Russia, Japan, ESA and America, with cosmonaut Sergei Vladimirovich, ESA astronaut Pedro Duque, taikonaut Ye Guangfu, Japanese astronaut Aki Hoshide and NASA astronauts Ricky Arnold and Jessica Muir taking part.

This picture was taken on the second day underground for the 'cavenauts'. They will spend six nights without sunlight, setting up basecamp in the Sa Grutta cave in Sardinia, Italy. As with any astronaut mission, science and technology are an important part of the undertaking. The astronauts are making 3D maps of the caves they explore using photograph-based measurements.