There are men, there are brave men, and then there's an Austrian skydiving expert named Felix Baumgartner, who later this year will take a flight in a stratospheric balloon more than 120,000 feet up and attempt to become the first person to break the sound barrier (approximately 690 mph) in a freefall.

On January 22, Baumgartner and several members of the Red Bull Stratos team publicly unveiled for the first time the details of their "Mission to the Edge of Space," for which Baumgartner is the Test Jump Pilot.

According to the company, "This is very much a step into the unknown; no freefall -- let alone a supersonic one -- has been successfully completed from the target altitude."

The goal is obvious -- get Baumgartner safely back to Earth. But the challenges are innumerable. Keep reading for more details about the incredible mission.

"The main challenges," says Art Thompson, the team's Technical Project Director, "concern pressure, thermal -- hot and cold temperatures, and acceleration and deceleration through three layers of space."

Baumgartner will wear a pressurized suit and helmet along with his parachute and chest pack with data recorders, but even the equipment presents a challenge.

"It's NOT comfortable being in a pressure suit," says Thompson. "People get antsy wearing it ... we wanted to see if Felix freaked out in the suit, but he was fine."

Baumgartner is an accomplished BASE jumper and he's set records before which include a flight across the English Channel with a carbon wing. But he's never done anything like this. When asked if he was nervous, he answered in the affirmative. "Yes, there's fear," says Baumgarter. "But I use fear to my advantage, to keep focused."

Joe Kittinger, a retired United States Air Force colonel, is the only person who knows exactly what Baumgartner will feel when he opens the capsule and prepares to jump; he set the record that Baumgartner will attempt to break 50 years ago when he made a parachute jump from 102,800 feet in Aug. 1960, nine years before the Apollo mission.

Kittinger will also be the voice from the ground inside Baumgartner's helmet when the Austrian will otherwise be all alone at 23 miles above the Earth. Asked if he hesitated before he made his epic jump, Kittinger responded, "Hell no, I didn't hesitate. I was happy as hell to go back to a friendly place. Space is a hostile environment."

Baumgartner will be there soon. The rest of us can watch live images of the incredible mission online, from the comfort of home. Pajamas are optional.