What are the effects of space travel on the human body?

Commander Chris Hadfield has arrived safely back on Earth after his stint on board the International Space Station - but how has five months in space affected the Canadian astronaut?

Space wreaks havoc on almost every part of the human body because there is less gravity to create the conditions we experience living on Earth.



   Astronauts have to live in cramped conditions while in Space.

To try to avoid this, while they're in space astronauts have a special diet and have to do up to two hours of exercise per day.

 

Even then, after five months in orbit above the Earth, an astronaut like Commander Hadfield would typically lose as much as 40% of muscle and 12% of bone mass, says Jeremy Curtis from the UK Space Agency.

"The muscle loss is the equivalent of a 20-year-old turning into a 60-year-old over a period of three months," he says.

 

The 53-year-old astronaut will experience problems standing up and balancing - and he won't be able to drive to begin with.

He'll have to undergo a special rehabilitation programme for the next year to rebuild his muscles and bones - and he may never regain his previous bone mass.

The exposure to higher levels of radiation in space also means Chris may be more likely to suffer from cancer later on in life.

But on the plus side, scientists say studying the effects of space flight on the human body can help with developing new treatments for diseases like osteoporosis and cancer here on Earth. Thanks Commander Hadfield!