I wish the world could see what I can see. Sometimes you have to get up really high to understand how small you really are. I'm going home now.

--Felix Baumgartner

WITH THOSE WORDS, Felix Baumgartner, 43, stepped into thin--very, very thin--air and began a historic plummet back to Earth. It was one small step for a man, one vicarious giant thrill ride for the rest of humanity.

"Most men lead lives of quiet desperation and go to the grave with the song still in them," wrote Henry David Thoreau. Not Mr. Baumgartner. The Austrian extreme-sports enthusiast has jumped from the hand of the Christ the Redeemer statue in Rio de Janiero. He's skydived across the English Channel wearing a special carbon wing. And he set the record for the world's highest parachute jump from a building when he leaped from the Petronas Towers in Kuala Lumpur, Malaysia.

Now, Mr. Baumgartner, working with a team from Red Bull Stratos, has topped even these feats. Clad in a custom space suit, he ascended in his specially made, climate-controlled capsule for three hours, tugged aloft by a 55-story helium balloon one-tenth the thickness of a plastic sandwich bag. Upon reaching the desired height--5,000 feet above the highest-ever jet flight--he depressurized his capsule, opened the hatch, walked out onto a tiny platform, and stepped off into the nothingness of near space, the New Mexican desert a small brown target below.

His descent, which reached unconfirmed speeds of 833.9 mph, easily breaking the sound barrier, lasted 10 minutes. To the relief of family, friends, his team, and viewers, he landed gracefully on his feet and sank to his knees, raising his hands in victory.

Mr. Baumgartner's achievement, on the 65th anniversary of Chuck Yeager's sound-barrier-breaking flight in a Bell X-1 aircraft, was no frivolous publicity stunt. It was a victory for human courage, science, and wonder.

The stratospheric leap proved that the human body, properly attired, could withstand extreme speeds and falls from great heights. The data collected might save astronauts' lives. Thirty cameras recorded the event live, so earthbound viewers could share it (over 5 million did). And despite his personal courage, all the high-tech preparation, and the expert team backing up Mr. Baumgartner, as he stood on his platform he felt small.

That, perhaps, is his greatest success: The extraordinary Mr. Baumgartner felt small and full of wonder--like a child on Christmas morning or a stargazer under a clear, black sky. The universe is far more grand than we dare imagine, even in our bravest, biggest moments.