(ROSWELL, N.M.) -- In a jump set to break the sound barrier, as well as the world record for highest skydive, Austrian skydiver Felix Baumgartner is ready to leap from the edge of space -- 23 miles above Roswell, N.M. -- on Tuesday.
When he jumps, Baumgartner will accelerate from zero to 690 miles per hour in 35 seconds, and become supersonic for almost a minute of the roughly 10-minute leap. This feat could ordinarily only be accomplished by a supersonic jet, or perhaps the space shuttle. But the 43-year-old daredevil believes he can do it using only his body.
"I practiced this for so many years, and now, we are almost there, so this is my biggest dream," he said.
Baumgartner's dream would be most people's nightmare. To get to 120,000 feet above Earth -- four times higher than most passenger jets fly -- Baumgartner will hitch a ride on a capsule attached to a balloon 55 stories tall.
"We are using a helium balloon to get to the stratosphere, but to get there we have to transit the death zone," Jonathan Clark Stratos, the project's medical director, said.
The pressure is so low at 120,000 feet that if Baumgartner's suit fails, his lungs would burst and his blood would boil. But the most dangerous moment of the jump comes when Baumgartner opens the capsule door and jumps out.
Threats of extreme cold, extreme temperature fluctuations, the possibility of an uncontrolled flat spin -- which could hit 220 rpm -- drogue chute failure, spacesuit puncture, and life support systems' failing are all potential threats for Tuesday's feat.
Baumgartner has successfully leaped twice from lower altitudes, but 120,000 feet will shatter the record set 52 years ago by former Air Force pilot Joe Kittinger, who is now 84 years old and admitted he was a little jealous.
"Hell yes," Kittinger said, when asked about Baumgartner's exploit. "If he decides he doesn't want to do it, I will go."
Baumgartner, who has a "Born to Fly" tattoo on his arm, said not a chance.
"It's just me. I like paragliding. I like helicopters. I just love to be near the sky, that is my second home, that is where I belong," he said.
Copyright 2012 ABC News Radio