With no reference points, “you don't know how fast you travel,” he said.
The 43-year-old former Austrian paratrooper had taken off early Sunday in a capsule carried by a 55-story ultra-thin helium balloon.
His ascent was tense at times and included concerns about how well his facial shield was working.
Any contact with the capsule on his exit could have torn his suit, a rip that could expose him to a lack of oxygen and temperatures as low as minus-70 degrees. That could have caused lethal bubbles to form in his bodily fluids.
But none of that happened. He activated his parachute as he neared Earth, gently gliding into the desert about 40 miles east of Roswell and landing smoothly. The images triggered another loud cheer from onlookers at mission control, among them his mother, Eva Baumgartner, who was overcome with emotion, crying.
He then was taken by helicopter to meet fellow members of his team, whom he hugged in celebration.
Coincidentally, Baumgartner's accomplishment came on the 65th anniversary of the day that U.S. test pilot Chuck Yeager became the first man to officially break the sound barrier in a jet.