Discovery Channel President Eileen O'Neill says the network documents the world's good and bad sides alike
Follows tightrope canyon crossing
Walk accounted for about 24 minutes of two-hour special, which drew 8.5 million total viewers
The Discovery Network stunt special drew millions of viewers
Feat called "greatest stunt of all time"
Wallenda has no hidden parachute, Discovery says
As he prepares to cross with no net or harness, he says the only things that scare him are elephants