He's now comfortable in the suit for five to six hours at a stretch and more.
"When you close your visor, it's your own little world. You don't hear anything from the outside anymore. The only thing that you hear is yourself breathing all the time. Then you start thinking about bad things and it's getting worse in a very short amount of time," Baumgartner says. "Your brain sometimes does fancy things."
Kittinger, by contrast, was a test pilot and used to pressure suits. In 1972, his fighter jet was shot down and he ended up a Vietnam POW, surviving 11 months of torture at the "Hanoi Hilton" prison. In the next cell was Sen. John McCain.
Kittinger's Project Excelsior was Air Force. Baumgartner's Red Bull Stratos effort is sponsored by the energy drink maker.
Both men had two test jumps before the grand finale.
Red Bull Stratos: http://www.redbullstratos.com
National Museum of the U.S. Air Force: http://tinyurl.com/2dsnn6