CNN CNN International March 28, 2015 07:56:00
Kelly will take part in studies to find out how low gravity impact his eyes, heart, bones, even his brain. about 1/3 of american astronauts have developed vision problems. it may be because without gravity, bodily fluids float up to their heads causing structural change in their eyes. that theory has never been fully tested. nasa scientist have documented cardiac arith mays and -- arrhthymias and more. also astronauts are at greater risk for broken bones and osteoporosis. how is being confined on a space station for long periods of time affect your thoughts and behavior in nasa says knowing th...