Felix Baumgartner Preps To Be the First Skydiver To Fall Through the Sound Barrier

Felix Baumgartner has a dream: to break the world record for highest jump

and

the sound barrier all in one go. Without any kind of aircraft. It sounds kinda crazy, but he's getting close to the historic jump. Last week, he made his final dress rehearsal before the big day.

The sound barrier, the compression of air as something moves through it approaching the speed of sound, was thought to be an insurmountable barrier in the sky for the first half of the 20th century. For years pilots tried pushing their airplanes through this invisible wall, but to no avail. The compressed air buffeted their airplanes, shaking them beyond control or tearing them apart. It wasn't until 1947 that a pilot broke through: Chuck Yeager in the specially crafted X-1 managed to pierce through the wall of air and reach supersonic speeds.

Baumgartner wants to do the same without the benefit of an aerodynamic casing like an airplane. A pressurized suit loaded with biomedical sensors will be his only protection when he jumps out of a specialized balloon from 120,000 feet and breaks the sound barrier on his way to the ground. As a point of reference, a cross country commercial flight hits about 30,000 feet and space starts at about 264,000 feet.

The pressurized suits is a necessity. With air temperatures below 70 degrees Fahrenheit and a thin atmosphere, his blood would boil if exposed to the air. His suit is a custom design made by the David Clark Co., the company that made the first pressure suits worn by World War II pilots performing high speed manoeuvres.

Before Baumgartner, Joe Kittinger set the with a jump from 102,800 feet on August 16, 1960. His was part of the US Air Force's Project Excalibur, a program designed to determine whether parachutes were a suitable escape method from a spacecraft or high-altitude aircraft. Kittinger's record has held since 1960.

When Baumgartner makes his record-breaking jump, he'll be starting about halfway up the second layer of our atmosphere, the stratosphere. That's where the project, which is fittingly sponsored by Red Bull, gets its name: the Red Bull Stratos Event. And the big day is fast approaching. Currently set for August or September, Baumgartner made his last test jump this week.

The test jump had been set for Monday July 23 – a review of nine years of weather data for Roswell, New Mexico suggested the date would have clear skies. But two days of storm clouds led to a two-day delay in compliance with US Federal Aviation Administration regulations. To jump, Baumgartner needs at least half clear skies and three miles of horizontal visibility. So the test was pushed back to Wednesday, a nice clear day over Roswell. Baumgartner jumped from 18.3 miles – 96,624 feet – and fell for 3 minutes and 48 seconds before a 10 minute and 36 second decent by parachute.

The 120,000 foot jump will see Baumgartner fall one mile every five seconds. "This is how fast you travel at supersonic speed," he explained. "It’s hard to believe it, if you put it that way, but I love it." The jump isn't just going to smash a historical record, it's going to return valuable medical data about how the body responds to extreme environments.

The whole thing sounds like a teenager's insane quest to get into the history books, but Baumgartner isn't. The 43-year-old is no stranger to skydiving and base-jumping – he's made over 2,500 jumps form airplanes and from some of the highest natural and man-made structures on Earth. He even jumped 600 feet into a pitch black cave in Croatia. All of the this begs the question, What on or even far away from Earth do you possibly do next after skydiving from space?

• Joe Kittinger Was Jumping From the Stratosphere Before It Was Cool
• In Case of Emergency, Astronauts Slide Down a Giant Zipline and Drive Away in a Tank
• He Flew a Balloon into Space and Jumped: A Q+A with Joe Kittinger