100 days in isolation or 60 days in bed – apply now for the isolation or bed rest study
December 1, 2025 | Research for future space missions
100 days in isolation or 60 days in bed – apply now for the isolation or bed rest study
Privacy only found in the sleeping pod
As part of ESA's SOLIS8 isolation study, three men and three women simulated a space mission for eight days. Participants had their own sleeping cabins within the module – the only areas besides the toilets that were not monitored by cameras. The study, conducted at DLR's :envihab facility, is preparation for a 100-day isolation study in 2026.
Six sleeping capsules are located above and adjacent to each other in the M5 module. They have their own ventilation system and offer some privacy. As part of ESA's SOLIS8 isolation study, three men and three women simulated a space mission for eight days. The study, conducted at DLR's :envihab facility, is preparation for a 100-day isolation study in 2026.
The SOLIS100 and SMC3 studies will start in spring 2026 at DLR's :envihab facility in Cologne, Germany.
Applications are open until 12 December 2025.
Applicants will go through a multi-stage selection process.
The studies will investigate the effects of isolation (SOLIS100) and microgravity in space (SMC3).
Focus: Space, exploration, space medicine
What happens to us humans if we spend 100 days isolated in a confined environment, without friends or family, under strict rules, in a small team and cut off from the outside world? This is the central question of the SOLIS100 isolation study, which the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) will conduct in Cologne starting next spring. The study was initiated by the European Space Agency (ESA) and investigates the effects of isolation on health, performance and wellbeing. Applications are open until 12 December 2025 via the website 'dlr-probandensuche.de'. The six participants must meet various requirements and will go through a rigorous preselection process. At the same time, interested individuals can also apply for the next bedrest study at DLR (SMC3) until the same date, 12 December 2025. For SMC3, conducted in collaboration with NASA, DLR is looking for twelve 'terrestrial astronauts'.
"Future space missions will go beyond Earth's orbit and target distant destinations such as the Moon or Mars. As these missions involve long periods in weightlessness, it is more important than ever to prepare astronauts for the psychological and physiological challenges," says Amelie Therre, head of SOLIS100 at the DLR Institute of Aerospace Medicine. "Missions to the Moon and Mars require mental and physical resilience, independence and the ability to thrive in isolated and confined environments. To carry out such missions successfully and ensure the safety of astronauts, we must investigate the effects of these extreme conditions on human health, behaviour and performance."
Life in a confined habitat
A trip to the Moon takes approximately three days. Travelling to Mars takes about six months – and that's only when Mars and Earth are in a favourable alignment. Although Mars is Earth's direct neighbour, it is still at least 55 million kilometres away. By comparison, the Moon is 'just' 380,000 kilometres from us. Anyone who spends months travelling in a spacecraft or living in a habitat hundreds of thousands of kilometres away from home must cope with extraordinary conditions: they not only have to get along with their crewmates, but also have to adjust to the habitat and the distance from home, manage resources and work effectively to support the mission. SOLIS100 addresses these challenges, assessing the psychological and physical risks associated with isolation and confined environments during long-duration missions.
To this end, six people will live for 100 days in a simulated space station with limited resources. The space station is located in a laboratory at :envihab, DLR's aerospace medicine research facility in Cologne. The participants will follow the same daily routine as astronauts during a mission: working together as a crew, performing scientific tasks, exercising and taking care of their 'space station'.
Task during the study: docking with a virtual spacecraft
The SOLIS8 study paved the way for the SOLIS100 study. Participants followed a fixed schedule with different tasks. Among other activities, they had to dock a virtual space capsule to a spacecraft. The experiment simulated six degrees of freedom, just as in microgravity. As part of ESA's SOLIS8 isolation study, three men and three women simulated a space mission for eight days. The SOLIS100 study, which will also be conducted at DLR's :envihab, is scheduled to begin next spring.
The six international crew members should have a profile similar to that of astronauts. They must be between 25 and 55 years old and physically fit. They should have at least a bachelor's degree; a higher degree and specialist knowledge in relevant areas are an advantage. The study team will assess the medical and psychological suitability of the applicants through questionnaires, tests and examinations. As the study language is English, very good English skills are required. Including preparation and the subsequent recovery phase, SOLIS100 will run for 126 days. The ESA study is scheduled to begin in April 2026. SOLIS100 was preceded in July 2025 by the eight-day SOLIS8 study. Further information: 100-day space analog mission: Test subjects wanted for an isolation study at DLR.
Or lying in bed for 60 days – for the space effect
Also at :envihab – and likely at the same time as SOLIS100 – the third campaign of the Sensorimotor Countermeasure (SMC) bedrest study is taking place. The study investigates how sensorimotor impairments caused by weightlessness can be counteracted.
Future astronauts will be exposed to prolonged periods of microgravity, working on the surface of the Moon – where gravity is only one-sixth of Earth's – and returning to the space station in lunar orbit. They must be able to move properly and safely and require strength. However, future space stations will have limited space for large training equipment. "The study investigates how relatively small, lightweight training methods can help preserve musculoskeletal function. To do this, we first simulate the effects of weightlessness. The participants do not just lie in bed for 60 days. The bed is also tilted down by six degrees towards the head, which means the head is lower than the feet. The body then shifts fluids towards the head, as they do in microgravity. Just as with astronauts, muscle mass then decreases and the sense of balance deteriorates," explains Stefan Möstl from the DLR Institute of Aerospace Medicine, who is leading the bed rest study.
The bed rest study, conducted in collaboration with NASA, investigates how longer space missions affect astronauts and what countermeasures are possible. The Sensorimotor Countermeasures Study (SMC) lasts 88 days, 60 of which the participants spend in bed in a six-degree head-down position. The study is being carried out at :envihab, the research facility of the DLR Institute of Aerospace Medicine in Cologne.
Video: Research for the future of space – DLR is looking for terrestrial astronauts
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Video: Research for the future of space – DLR is looking for terrestrial astronauts
The bed rest study, conducted in collaboration with NASA, investigates how longer space missions affect astronauts and what countermeasures are possible. The Sensorimotor Countermeasures Study (SMC) lasts 88 days, 60 of which the participants spend in bed in a six-degree head-down position. The study is being carried out at :envihab, the research facility of the DLR Institute of Aerospace Medicine in Cologne.
The test subjects are also referred to as 'terrestrial astronauts'. While one group acts as a control group and 'only' lies in bed, the others receive additional training for their musculoskeletal system during their bed rest. One group trains their balance using a 'GravityBed': participants 'float' on a compressed air-supported sled while their feet are pressed against a balance board via a strap system. They are required to keep the board stable by making compensatory movements with their legs and upper body. The terrestrial astronauts in the third group exclusively train their leg muscles using electrical impulses (electromyostimulation). As both training methods would also be suitable for use on a future space station, they are now being tested in Cologne.
Wanted for bed rest study: healthy individuals with an average level of fitness
For the NASA bed rest study, DLR is looking for twelve healthy men and women between 24 and 55 years old, between 1.53 and 1.90 metres tall and with a body mass index (BMI) between 18 and 28 kg/m2. In addition to other requirements, participants should have an average level of fitness. Good German language skills are also required. Including preparation and follow-up, the test subjects will remain in :envihab for exactly 88 days. All applicants must first fill out a questionnaire for pre-selection, followed by further selection steps. Further information: Test persons wanted: Campaign 3 - Sensorimotor Countermeasure Study (SMC)
The :envihab aerospace medicine research facility in Cologne
What would happen to the human body during a flight to Mars? How do patients' bodies react when confined to bed for extended periods? How does lighting affect our mood? Are there measures to counteract resulting adverse effects? Answers to these questions are also important here on Earth to better understand the effects of ageing, prolonged bed rest, immobilisation and isolation.
The DLR Institute of Aerospace Medicine is a world-leading research institute in this field. At its unique :envihab medical research facility, the institute carries out pioneering research into preserving human health and performance. Within the 3500-square-metre facility, the effects of extreme environmental conditions on humans – and possible countermeasures – are investigated.
