Charles Lindbergh: Those cross-Atlantic trips we take for granted all ended in a watery grave before Lindbergh's 1927 solo nonstop on the Spirit of St. Louis, which took a speedy 33-1/2 hours to hop the pond. For good measure he later invented a glass pump that eventually made heart surgery possible.
Yuri Gagarin: If humans weren't meant to fly, they certainly weren't intended to be shot into space. But tell that to Gagarin, the first man to leave the earth. Yuri's hardiness (as a child he ran from the Nazis) came in handy in a space program that didn't care so much if cosmonauts returned alive.
Steve Fossett: Before disappearing last September, Fossett set 116 different world records in vehicles from gliders to catamarans. He also climbed six of the seven summits (sans Everest) and competed in the Iditarod, triathlons, and 24 Hours of Le Mans…all despite suffering from asthma.
Richard Byrd: After becoming a pilot during World War I, Byrd combined his flight skills with an obsession with the frigid, copiloting a 1926 flight to the North Pole that earned him the Congressional Medal of Honor. He followed this up with a first flight to the South Pole, one of his five Antarctic expeditions.