SOLIS100 isolation study begins in Germany

For 100 days, the participants will live and work under conditions designed to mirror the demands of long‑duration space missions beyond low Earth orbit.

To shed light on the scientific objectives behind the study and its role in preparing for future human space exploration, we spoke with Angelique Van Ombergen, ESA’s chief exploration scientist.

With a background in medical sciences and extensive experience in human spaceflight research on ground and linked to the International Space Station, Angelique explains how studies such as SOLIS100 help ESA address the human challenges of missions to the Moon, Mars and beyond.

Can you explain what the SOLIS100 isolation study is?  

Angelique: The SOLIS100 Isolation Study is a 100‑day human isolation experiment designed to better understand how prolonged confinement and social isolation affect people.  The study focuses on the psychological, behavioural, cognitive and physiological challenges that astronauts are expected to face during future long‑duration missions, such as extended stays on the Moon or journeys to Mars.  

SOLIS100 is conducted at DLR’s :envihab research facility in Cologne, Germany — a highly controlled space analogue environment specifically designed for human spaceflight research. Six participants aged between 26 and 32, from six different European countries, live and work in isolation for the full 100 days, following structured daily schedules and operational constraints similar to those of a space mission.

We will perform a wide range of scientific experiments, as well as technology demonstrations related to space exploration. We will also run experiments from the United Arab Emirates’ national space centre, MBRSC.

What do you expect to gain from this research and why is it important for future missions?

Angelique: The results of studies such as SOLIS100 help identify early markers of health and performance degradation, improve understanding of why individuals adapt differently to extreme environments and refine medical and operational risk models.

Data collected during bed rest and dry immersion studies support the development of countermeasures to protect cardiovascular health, reduce the risk of thrombosis and mitigate musculoskeletal and neuro‑ocular changes associated with microgravity.

In parallel, isolation studies such as SOLIS100 provide insights for crew psychological support, selection and training, circadian rhythm management and team cohesion. These aspects are essential for missions in which real‑time support from Earth is limited or impossible, such as long‑duration lunar missions or future journeys to Mars.

How does SOLIS100 differ from other spaceflight analogue studies, such as bed rest, and why are both approaches important for future exploration missions?

Angelique: Bed rest and dry immersion studies focus on a different aspect of spaceflight. They are microgravity analogues, designed to reproduce the physiological effects of weightlessness on the human body, such as fluid shifts, cardiovascular deconditioning, muscle and bone loss, and changes in blood flow.

By contrast, SOLIS100 does not simulate microgravity. Instead, it investigates the human consequences of long-term isolation and confinement, including limited social interaction. The study examines impacts on mental health, team dynamics, stress regulation, sleep, cognitive performance, as well as changes in the crew and habitat microbiome.

Both approaches are essential, as no single ground‑based analogue can replicate all aspects of spaceflight. Physiological deconditioning caused by microgravity, psychological strain resulting from isolation and operational challenges linked to increased autonomy and decision‑making represent different yet interacting risk domains.

By running bed rest, dry immersion and isolation studies in parallel, ESA can address the full spectrum of risks relevant to future exploration missions. This integrated research strategy ensures that both the physiological and human behavioural challenges of long‑duration missions are addressed.

How were the participants selected for this study?

Angelique: Participants for SOLIS100 were selected through a rigorous recruitment and screening process managed by DLR, in close coordination with ESA. Recruitment began with a public call, followed by multiple stages of medical, physiological and psychological evaluation.

Only healthy individuals who met strict inclusion criteria and demonstrated strong motivation, resilience and compliance were selected. The study crew is composed of six healthy volunteers, aged between 26 and 32 years.

The participants represent a range of nationalities, including German, Polish, Dutch, Portuguese, Spanish and French, reflecting the international nature of European space exploration.