charlie linville , 29 , from boise , idaho , is using a specially designed metal foot outfitted with a climbing boot and another one with crampons in his quest to conquer the 8,850-meter -lrb- 29,035-foot -rrb- summit next month .
he was an explosives expert serving in afghanistan in 2011 , when he went to investigate an explosion that wounded his colleague .
he has been climbing since with the heroes project , a nonprofit organization that helps wounded veterans .