Jeb Corliss wants to fly — not the way the Wright brothers wanted to fly, but the way we do in our dreams. He wants to jump from a helicopter and land without using a parachute. And his dream, strange as it sounds, is not unique. Around the globe, Mr. Corliss said, at least a half-dozen groups — in France, South Africa, New Zealand, Russia and the United States — have the same goal in mind. Although nobody is waving a flag, the quest has evoked the spirit of nations’ pursuits of Everest and the North and South Poles. “All...