Nasa is about to send two men to the International Space Station for a whole year – the longest human mission it has ever launched.
With space agencies around the world ramping up their research into the possibility of sending humans to Mars in the not-too-distant future, this experiment aims to determine how the body responds, physiologically and psychologically, to being away from Earth for a long time – a trip to Mars and back would involve people being in space for between two and three years.
The two astronauts involved, Scott Kelly from the US and Mikhail Kornienko from Russia, will take off from Kazakhstan tomorrow morning aboard a Soyuz rocket. Six hours later they will reach the International Space Station (ISS), where they will spend the next 12 months carrying out medical experiments.
It will be no holiday for the men – they have both been to the ISS before, but only for as long as six months at a time. Doctors are aware that spending long periods of time in space can have very negative health impacts.
So what exactly can being in space for a year do to the body? And what signs of poor health will researchers be looking out for in the two men? Bones and muscles are known to weaken in a weightlessness, which can give rise to diseases such as osteoporosis, while body fluids also shift in the absence of gravity, putting strain on the brain and the eyes. The immune system is thought to falter, and there is a possibility our genes change under such circumstances.
For the first time, Nasa will be able to find out exactly how bad these impacts are, and in doing so will pave the way for long-term missions in the future.