Spend two months lying down to help space research: volunteers have agreed to stay in bed under surveillance in Toulouse, in order to recreate the absence of gravity and thus contribute to improving the living conditions of astronauts during their missions. “We see ourselves getting thinner day by day at the start,” smiles Matthieu, one of the twelve men selected for this experiment, who has been well established for five weeks at the Medes clinic, a health subsidiary of the National Center for Space Studies ( CNES).

The bed of these volunteers, chosen from 3,000 candidates and whose names are not communicated, remains tilted for 60 days at an angle of -6 degrees, the best able to reproduce the effects of weightlessness to which the astronauts are subjected. during their stays in space. “We have entered the space exploration phase. We are really looking to go to the Moon and Mars, it is no longer a fiction and it involves long-distance flights of two to three years, ”explains Audrey Bergouignan, from the National Center for Scientific Research (CNRS). “Exposure to microgravity will impact all physiological systems (…) and cause alterations that we try to understand and prevent”, specifies the researcher, before adding: “To prevent them, we implements protocols that we test upstream here, before testing them in space.”

” READ ALSO – Countering the effects of weightlessness

Everything is therefore organized in order to allow the 12 hospitalized to remain in bed: nearly a hundred people are mobilized to follow them over the duration of the study, from caregivers to researchers. “We are in very favorable conditions for bed rest, every time we need something, we just have to call the medical staff”, explains Matthieu, a 39-year-old market gardener whom his girlfriend convinced to try l adventure, remunerated 18,000 euros for three months of presence on site.

In order to compare the evolution of their organism according to their physical exercise, the volunteers are divided into three groups: one performs 30 minutes of recumbent bike per day, the other is not subjected to any physical activity, while the third must pedal while in a moving human centrifuge.

“The idea is to see if the artificial gravity created by the centrifuge when it turns improves the effects of the physical exercise of the bicycle”, specifies Marie-Pierre Bareille, head of the space clinic to which the study was entrusted by CNES and the European Space Agency (ESA). If the results are conclusive, this artificial gravity could be recreated on board long-duration missions in space, once the technical constraints have been resolved.

” READ ALSO – Astronaut, “it’s a life that I did not necessarily expect”, confides Thomas Pesquet

“The challenge, she says, is that the crews are fit and able to work during extra-vehicular outings” during which they may have to perform quite physical tasks. “During a trip to Mars, astronauts could lose up to 15% of their mass”, indicates Audrey Bergouignan. The participants in the experiment take turns, sometimes on a bike designed for recumbent pedaling, sometimes in the centrifuge, while the laughter bursts out with the caregivers who share their very particular daily life.

“I’m not bored, everyone is very nice,” says Alejandro, a 26-year-old Spanish aeronautical engineer who lives in Toulouse. “We are in contact with the other chambers. We organize video game tournaments on Mario Kartou Fifa”, he laughs, while pedaling under the supervision of a trainer. For them, the experience will end with an accompanied return to normal life in early July, while 12 other volunteers will submit to the same living conditions in 2024.

The clinic selected only men in order to “limit the variables” between the volunteers, according to the organizers, and to obtain the most “homogeneous” results possible. But the conclusions of the study carried out in Toulouse will not only apply to the space domain. “Knowledge of hyper-sedentary lifestyle will be useful for everyone to know how the lack of physical activity acts on the body,” says Marie-Pierre Bareille, referring to the elderly or those suffering from pathologies such as osteoporosis. .