Bruce Sterling @bruces (@bruces.mastodon.social.ap.brid.gy)

8 640 000 seconds to Mars Imagine living in a small, sealed habitat for 100 days with five other people, cut off from the outside world. No fresh air, no spontaneous walks, no quick trips to the store — just you, your team and a carefully planned routine. This is what ESA’s upcoming SOLIS100 study is all about: understanding what it takes for humans to thrive in isolation and confinement, just as future astronauts will need to do on missions to the Moon and Mars. Starting in April 2026, the participants will enter the German Aerospace Center’s :envihab facility in Cologne, Germany, and begin a journey that mirrors the conditions of a lunar or martian outpost. For three months, they will share a confined space, manage limited resources and work together on scientific and operational tasks. Every detail, from their sleep patterns to their nutrition and psychological well-being, will be monitored to learn how isolation affects health, mood and performance over time. Why does this matter? When we send astronauts beyond Earth, they will face extreme isolation for months or even years. Small stressors can build up, and even simple challenges like disrupted sleep or strained communication could impact the success of the mission. SOLIS100 will help ESA and its partners develop strategies to keep crews healthy and resilient, whether on the lunar surface or during a long voyage to Mars. Each participant will have a private sleeping pod inside the isolation habitat, providing personal space within a shared environment. The study includes teamwork, scientific research, operational tasks, and regular physical training to maintain health. Nutrition and psychological well-being will be assessed throughout the mission. This study builds on SOLIS8, an ESA-led isolation pilot conducted in 2025. This eight-day mission tested equipment and procedures to prepare for the main investigation. Now, the study is scaling up to 100 days to simulate the complexity of a true deep-space mission — more autonomy, more resource management and more opportunities to learn how humans adapt when the world outside is out of reach. Credits: DLR https://www.flickr.com/photos/europeanspaceagency/54977606704/