ESA - European Space Agency on Instagram: "Would you spend four days underground with zero sunlight? 🤔 Five explorers just spent two weeks training for space, four days of it in total darkness. And they’d do it all again in a heartbeat. This crew had to become a team from day one, because underneath the Apennine Mountains in Italy, our CAVES 2026 course doesn’t ease you in gently. Two intense weeks of training built up to a four-day expedition deep into a pitch-black cave. No windows, no fresh air, no popping outside for a breather. It’s basically a space mission, just swap the stars for stalactites. That early bond is what made the difference. Five people who’d barely worked together turned into a safe, effective, brilliantly organised unit, running a real space analogue mission underground. They mapped cave systems no one had ever explored before, built their own phone lines from scratch and ran science experiments on microbes, radon and carbon dioxide levels along the way. Halfw...