At an altitude of 120,000 feet, Austrian daredevil Felix Baumgartner, clad in a pressurized suit with oxygen tanks, will jump out of a helium balloon he boarded in New Mexico. At such an extreme height, Baumgartner plans to reach supersonic speeds.
Within 30 seconds of his free fall, he expects to exceed 690 miles per hour (the speed of sound), and therefore breaking the sound barrier.
"That is what we want to find out: What happens to the human body when it breaks the speed of sound," Baumgartner explains, DailyTech reports.
The first step in the attempt will be riding a helium balloon to an altitude of 120,000 feet above sea level -- almost 23 miles -- higher than anyone has ascended in a balloon before.
Then, wearing a pressurized suit and oxygen tanks, he plans to jump out of his capsule for a five-minute fall back to Earth. Within the first 30 seconds, he expects to be falling faster than the speed of sound, which at that altitude is around 690 miles per hour. Crossing that barrier would mark a new test of the limits of the human body, CNN reports.