Skydiver Felix Baumgartner is aiming to pull off a record-breaking free-fall jump from the edge of space Tuesday, wearing nothing but a space suit, a helmet and a parachute.

His goal is not only to jump from a higher altitude than anyone ever has -- 120,000 feet, more than three times the cruising altitude of the average airliner. He also hopes to be the first person to break the sound barrier, without the aid of anything besides the space suit. At that altitude, the thin air provides so little resistance that after just 40 seconds, he is expected to be free-falling faster than 690 miles an hour.

"I'm not nuts," Baumgartner said when CNN first interviewed him about the project in 2010. "You know, our records are meant to be broken, and I'm a very competitive person. I like the challenge."

But on a more serious note, he added, "Of course I'm afraid of dying, because I worked so hard to reach this level. You know, I'm living a good life. I think the most important thing I'm doing is to come back alive."

Courtesy cnn.com