On the 29th of October 1908, a party of four men, led by Ernest Shackleton, set out to be the first to reach the South Pole. Three months later, their mission was in ruins and they faced certain death if they carried on. Just 97 miles from the South Pole, Shackleton turned back. One hundred years on, in October 2008, a team that included descendants of that original party, led by Henry Worsley, se...