Skydiver Felix Baumgartner is preparing to take the leap of his life aiming for the highest, fastest free fall in history.
If he survives, the man dubbed "Fearless Felix" could be the first skydiver to break the sound barrier. If he does not, his failure could be live-streamed on the internet for the world to see.
Rigged with cameras, the 43-year-old former military parachutist is scheduled to jump from a balloon-hoisted capsule 23 miles up near Roswell, New Mexico on Tuesday. He wants to break the record set in 1960 by Joe Kittinger, who jumped from an open gondola at an altitude of 19.5 miles. Kittinger's speed of 614 mph was just shy of breaking the sound barrier at that height.
Baumgartner, who has been preparing for the jump for five years, has made two practice runs from the Roswell area, from 15 miles in March and 18 miles in July.
And while he and his team of experts recognise the worst-case scenarios - including "boiling" blood and exploding lungs - they have confidence in their built-in solutions.
This death-defying venture is being sponsored by energy drink maker, Red Bull, which has funded other extreme athletic events. The project's team of experts has a plan for almost every contingency. The spacesuit and capsule were tested in the early skydiving practice runs. The company will not say how much the project, called Stratos for stratosphere, is costing.
Weather permitting, Baumgartner will be lifted into the stratosphere around 1400 BST by a helium balloon that will stretch 55 stories high. Once he reaches his target altitude, he will open the hatch of his capsule and make a gentle, bunny-style jump. Any contact with the capsule on his exit could break open the pressurised suit.
He hopes to reach a speed of 690 mph to break the sound barrier.
Baumgartner, who has made more than 2,500 jumps from planes, helicopters, landmarks and skyscrapers over the past 25 years, promises this jump will be his last.
He says he plans to settle down with his girlfriend and fly helicopters on mountain rescue and firefighting missions in the US and Austria.