This July 2007 image provided by NASA shows astronaut Clay Anderson waving during a spacewalk outside the International Space Station. Astronauts traveling to and from Mars would be bombarded with as ... more 
This July 2007 image provided by NASA shows astronaut Clay Anderson waving during a spacewalk outside the International Space Station. Astronauts traveling to and from Mars would be bombarded with as much cosmic radiation as they’d get from a full-body CT scan about once a week for a year, researchers reported Thursday, June 30, 2013. NASA aims to send a crew to orbit the red planet by the mid-2030s. (AP Photo/NASA) less 
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Associated Press | Photo By NASA
Thu, May 30, 2013 2:28 PM EDT