Studies carried out on astronauts have shown that lack of gravity leads to bone loss and muscle deterioration and causes bodily fluids to pool in the head, making it swell (astronauts really are big-headed). Crew on the International Space Station (ISS) frequently report the feeling of a head cold.

US astronaut Scott Kelly and Russian cosmonaut Mikhail Kornienko have recently begun a year-long mission to investigate the effects of long-duration space flight. However, bed rest studies on the ground in Envihab will enable doctors to examine a larger number of subjects under completely controlled conditions.

But do not imagine it is going to be any more comfortable.

Life at an angle

“To cheat gravity, we tilt the subjects head-down by six degrees,” says Limper. “This is very important, so that the head is below the rest of the body.”

Stuck at this peculiar angle, the volunteers will also be expected to eat a nutritionally controlled diet and go to the toilet using bedpans and urine bottles. They will be monitored 24 hours a day on close-circuit TV and even be transferred to special water-proof tilted beds to take a shower.

Dlr has carried out several previous bed rest studies in partnership with the European Space Agency. Results from these studies have also been used on Earth in studies of bone disease and to plan care for people confined to bed in hospital.

The latest research requires relatively fit men aged between 18 and 40. “A big problem for us is the variability between subjects,” says Limper, “and gender has a big effect but other investigations might use women.”

As well as spending life at an angle of -6 degrees – reading, sleeping, watching movies or playing video games – the subjects will also take part in a range of experiments. Over the three weeks inside the facility, they can expect to be measured, prodded, pricked and scanned in tests of blood, bone and muscle.