But it won't be all rest and relaxation, the European Space Agency said, because the volunteers in this bed-rest study will undergo regular and intensive daily activities, including tests and examinations, while prone in bed.
As we age, researchers said, our bodies lose bone density and muscle strength, something experienced by astronauts in space but at a much faster rate than on Earth.
The test is just one of many international bed-rest studies aimed at developing and testing countermeasures to the challenges of living in space, aging and long periods of immobilization after illness, researchers said.
Having volunteers in bed lying with their heads 6 degrees below the horizontal for long periods causes their bodies to react in similar ways to being weightless, but is cheaper and safer than sending them into space, they said.
The volunteers will be scientifically scrutinized to see how they adapt to staying in bed for long periods, the ESA said in a release from its Paris headquarters.