In its early moments this documentary, hosted by British actor Brian Blessed, ponders whether man could ascend the biggest mountain on Mars, Olympus Mons, a massive peak three times as high as Everest. It might have proceeded as a predictable vanity exercise for an actor, playing the hero, and dashing to a TV-produced finish line. In fact, Blessed proves he’s more than up to the task and the results make for breathtaking television.