Six volunteers locked in 100-day isolation to prepare humans for deep space missions

The participants entered a sealed habitat at the Envihab facility, where they will live and work in conditions designed to simulate the confinement, autonomy and psychological pressures of missions beyond low Earth orbit.

In Short

• Participants will follow strict routines mirroring future lunar and Martian missions
• Researchers are tracking sleep, stress, cognition, team dynamics and physical changes
• The study examines autonomy, confinement and delayed communication as major stressors

Six volunteers have begun a 100-day isolation mission in Germany, offering scientists a rare opportunity to study how humans cope with the extreme demands of long-duration space travel.

The experiment, known as SOLIS100, is led by the European Space Agency and conducted at the German Aerospace Center’s advanced research facility in Cologne.

The participants entered a sealed habitat at the Envihab facility, where they will live and work in conditions designed to simulate the confinement, autonomy and psychological pressures of missions beyond low Earth orbit.

Over the next three months, the crew will follow strict schedules and operational routines similar to those expected on future missions to the Moon and Mars.

According to ESA’s chief exploration scientist Angelique Van Ombergen, the SOLIS100 study focuses on understanding how prolonged isolation affects human psychology, cognition and physical health.

Researchers aim to identify early signs of stress, fatigue and performance decline, critical factors that could influence astronaut safety and mission success.

The six volunteers, aged between 26 and 32 and drawn from across Europe, will undergo a wide range of experiments during their stay. These include monitoring sleep patterns, stress levels, team dynamics and cognitive performance.

Scientists will also study physiological changes and shifts in the habitat’s microbiome, helping build a more complete picture of how humans adapt to confined environments.

Unlike other spaceflight simulations such as bed rest studies, which replicate the physical effects of microgravity, SOLIS100 is designed specifically to examine the psychological and behavioural challenges of isolation.

Limited social interaction, delayed communication and increased autonomy are all key stressors that astronauts will face on deep-space missions.

Researchers say such studies are essential because no single experiment can replicate all aspects of spaceflight. By combining isolation studies with other simulations, ESA hopes to better prepare astronauts for the complex realities of interplanetary travel.

The findings from SOLIS100 are expected to play a crucial role in shaping future mission planning, including crew selection, training methods and onboard support systems.

Insights gained could help develop strategies to maintain mental health, improve teamwork and ensure peak performance during missions where real-time support from Earth is limited.

As space agencies around the world set their sights on long-duration missions to the Moon and Mars, experiments like SOLIS100 highlight a key challenge: understanding not just how to reach distant worlds, but how humans can endure the journey.

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