What happens to a human body when it spends a year in space? Bones and muscles weaken because you don’t have to stand up or fight against gravity. The stomach floats free in the belly, making it feel like you’re permanently looping over the top of a rollercoaster, and fluids, free from the downward pull of the Earth, swell and puff your skin.
But that’s the stuff we know already from watching too many sci-fi movies. Right now, NASA is in the middle of a one-year study to understand what happens to us when we float free of gravity and outside the protection that the Earth’s atmosphere provides against space radiation.
The study follows two subjects–U.S. Astronaut Scott Kelly and Russian Cosmonaut Mikhail Kornienko. They’re spending a whole year on the International Space Station (ISS), which is double the normal term spent up there. Determining the long-term effects of space on our bodies is essential to extended future missions like a trip to Mars.
There’s an added twist to this mission. Scott Kelly has a twin brother, Mark Kelly, who is also an astronaut. This lets NASA study two genetically identical humans in different environments: Scott in space, and Mark down on Earth.
One of the largest experiments is the Fluid Shifts Investigation. The theory goes that the shift of fluids from the lower body, brought about by zero gravity, puts extra pressure on the brains of astronauts, and may even contribute to “decreased visual capacity.” Experiments are being run on both U.S. And Russian team members, using lower body negative pressure suits, which look a lot like Wallace and Grommit’s Wrong Trousers.
To do this, the teams are relocating to the Russian part of the ISS, because the Russian monitoring gear is fixed in place. But this has introduced one amusing problem. The plugs don’t match up, and Amazon doesn’t deliver adapters into Earth orbit (yet).
“The physical and power interfaces are completely different […] so we are redesigning these to work and fit the Russian outlets,” says NASA flight project manager Erik Hougland.
The study is the first to measure inter-cranial pressure during a mission, and hopes to figure out why astronauts’ vision changes in zero-gravity, and hopefully come up with a fix. “If we want to stay in space longer than six months to explore,” says Michael Stenger, co-principal investigator of the Fluid Shifts investigation, “we have to determine what causes these vision changes so that we can begin developing countermeasures to prevent them.”
It’s also good for inter-cranial pressure sufferers back on Earth. Normally, measurements are done using a lumbar puncture or by drilling a hole in the skull. The astronauts are interested in neither, so they have come up with a number of non-invasive tests that could be useful back down here.
Another area of study is nutrition. Despite such a controlled environment, astronauts are just like you and me when they get too busy–they don’t stop to eat properly. But in orbit it’s worse, because their bodies also have to cope with extra radiation and higher levels of CO2 in the air. In this case, the Twins Study helps out, because NASA has a nutritional control subject back on Earth.
As ever with NASA, the resources on the website are amazing, with photos and lots of detailed reports. You should definitely take a look.