The IsoRhythm project
SEFAS contributes essential expertise on circadian rhythms to the IsoRhythm project, part of ESA and DLR’s 100-day isolation study, SOLIS100. By analysing how isolation and confinement disrupt sleep–wake cycles and physiological stability, the project deepens our understanding of human resilience. These insights directly support SEFAS’ work on circadian disturbances in older adults, particularly in dementia and Parkinson’s disease.
About the research project
Future space missions will target multiple destinations, including deep-space environments beyond Earth’s orbit. These long-duration missions require thorough investigation, as the psychological and physiological preparation of astronauts is critical to mission success under extreme conditions. The European Space Agency (ESA) and the German Aerospace Center (DLR) launched SOLIS100, an isolation and confinement study designed advance human spaceflight research. The study will take place at DLR’s aerospace medical research facility :envihab in Cologne, Germany. To simulate real spaceflight conditions, six participants will live for 100 consecutive days in a confined, space-station-like environment with limited resources. SOLIS100’s primary objective is to investigate the effects of prolonged isolation and confinement on human behaviour, performance, and well-being. The study will generate valuable data on the physiological and psychological support required for future long-duration spaceflight missions.
IsoRhythm is one of 18 experiments participating in SOLIS100. The project focuses on the analysis of circadian rhythms, which play a fundamental role in regulating sleep and overall physiological functioning through their interaction with environmental and behavioural cycles.
Methods
Biomedical data, including movement, heart rate, heart rate variability, respiration rate, and peripheral body temperature, will be collected at well-defined timepoints during pre, during, and post mission. IsoRhythm will be responsible for the analysis of changes in circadian, psychological, and physiological outcomes over time. The protocol also includes an emotion recognition and processing paradigm, as well as menstrual cycle logging. Data will be analysed using dynamic systems and signal processing techniques, and validation will be performed using hair follicle analysis as a molecular reference for circadian phase.
Team
The SEFAS team consists of Researcher Monica Patrascu (PI), Professor Line I. Berge, Professor Elisabeth Flo-Groeneboom, and Researcher Valentina Casadei.
Impact
At SEFAS, circadian disruption is a well-established research topic, particularly in the context of neurodegenerative conditions such as dementia and Parkinson’s disease. Altered sleep-awake cycle patterns and instability of the rhythms are closely linked to diseases and quality of life. Although the causes can differ, circadian rhythms are similarly vulnerable to disruption due to altered habits, light exposure, irregular schedules, and changes in biological variables, conditions that are intrinsic to space missions as well, providing complementary data to support circadian research on older populations.
Status
SOLIS100 has received ethics approval and is currently recruiting participants. IsoRhythm is developing protocols and training materials in preparation for the experiment scheduled to begin in spring 2026.