One thing is sure: if Felix Baumgartner survives his jump from 37,576 meters (120,000 ft), he will be a star. He wants to break the sound barrier. And all that's stopping him is a parachute.
At 43 years of age, Austrian extreme jumper Felix Baumgartner has seen his fair share of panoramic views.
Baumgartner has climbed up high in order to just jump back down from high-points around the world.
He has jumped from the 88th floor of the Petronas Towers in the Malaysian capital, Kuala Lumpur - with just a parachute for protection.
He's also jumped from the right hand arm of the Christ statue in Rio de Janeiro, the Millau Viaduct (highest bridge in the world at 343 meters), and from the 91st floor of the Taipei 101 building in the Taiwanese capital.
And all of his jumps have been unauthorized. Baumgartner has often had to make a quick escape seconds after landing to avoid being arrested.
Higher and higher
Now, Baumgartner wants to go higher. Much higher.
His jump from an altitude of 37 kilometers (120,000ft) will start above New Mexico from within the stratosphere - at a distance that is four times higher than the world's highest mountain, Mount Everest.
And he wants to fall faster than the speed of sound to break a number of world records in the process.
But it could all go wrong - Baumgartner could die.
Baumgartner will be transported to his starting position on a massive helium balloon. Once he's there, he will jump from a special capsule and fall with speeds of about 1110 kilometers per hour (689 miles per hour).
After five seconds in freefall, will want to open his parachute and land 15 minutes later.
That's if everything goes to plan - the smallest error could mean disaster.
Without protective gear, Baumgartner would die almost immediately. But he is well prepared. His pressure suit has been designed by the same company that makes suits for NASA astronauts.
He also needs his own oxygen supply. At 3,000 meters, the air starts to get thin and by the time he reaches the stratosphere at 37 kilometers there will be almost no free oxygen at all.
Then, there's the drop in temperature and atmospheric pressure to deal with.
Baumgartner's pressure suit will have to bear it all.
"If the suit is damaged, or there's a leak, it would be fatal," says Martin Trammer of the German Aerospace Center (DLR). "At that altitude, all the water in an unprotected body would vaporize."
Then, gas bubbles would block the body's blood vessels, resulting in a heart attack or cerebral apoplexy.
Flat spin scenario
The experts are mostly worried about a phenomenon known as flat spin.
If Baumgartner starts to rotate involuntarily, it would be extremely difficult for him to stop the spin.
Flat spin occurs when there is not enough drag.
"If there's no drag, the air molecules are unable to maintain a stable position - you can lose control very easily," another expert at DLR told DW.
Trammer goes on to explain that when flat spin occurs, the body rotates faster and faster, diving like a spiral down to the ground. Blood rushes to the head and legs, but circulation stops, and the brain is starved, threatening unconsciousness. At the same time, the pressure builds on the body's blood vessels and in extreme cases it can lead to internal bleeding.
However, Baumgartner is prepared for this as well. If he experiences flat spin, falls into unconsciousness or loses control, a small stabilizing parachute will automatically open. Likewise, an extra emergency parachute will open if Baumgartner fails to open his parachute himself.
An army of medical professionals and technicians are on standby.
But Baumgartner is optimistic. He would have to be. He's spent the past five years preparing for this jump, and his test jumps from 30,000 and 21,000 meters were a success.