At 9.13 a.m. on 1 August 2026, two heavy double doors opened in Cologne. Behind them stood six people who had spent 100 days without daylight and without personal contact with family or friends.
The SOLIS100 study is meant to show what long isolation does to health, performance and wellbeing. The European Space Agency commissioned it, and the German Aerospace Center (DLR) carried it out. The answers are to prepare crews for flights to the moon and to Mars, where help cannot arrive quickly in an emergency.
The crew consisted of three women and three men aged between 26 and 32. They came from Germany, France, Italy, the Netherlands, Poland and Portugal, Deutsche Welle reports. Inside the :envihab facility they lived in cramped quarters with limited supplies. Their days consisted of experiments, medical measurements, a strict exercise programme and maintenance of the station. They usually spoke to the control centre over an intercom.
Once the doors opened, the crew's first stop was a meadow in the sunshine, DLR said. Fresh fruit, croissants and coffee were waiting for them.
What the crew takes away
The participants wrote down their first conclusions immediately. What matters most, they said, is a team that sticks together, complements each other and stays tolerant. Open and transparent communication helped, as did the mix of structure, discipline and fun. Contact with family and friends gave them a sense of connection.
The week after they emerged was also part of the study. The crew stayed together but could receive visitors, choose their food freely and use private devices again. Since 7 August the six have been back in their everyday lives. Including preparation and follow-up examinations, the project ran for 126 days.
The analysis now begins across 23 participating research teams. Project leader Amelie Therre says, according to Deutsche Welle, that the study serves to standardise data. Only then can support measures for future crews be compared. Anke Pagels-Kerp, a member of the DLR executive board for space, calls such studies indispensable for preparing people for the mental and physical strain of long missions. Firm conclusions will come only once the data from all phases has been analysed, meaning before, during and after the isolation.