Early in the morning, on Tuesday, October 9*, at an altitude of 120,000 feet (23 miles or 36 kilometers), Felix Baumgartner will step out of his balloon-borne capsule into the incredibly thin atmosphere of the stratosphere before plummeting head-first toward the Earth in a bid to not only overthrow the high-altitude free fall record set back in 1960, but also to be the first sky diver to breach the sound barrier by reaching a staggering speed of 690 miles per hour. Red Bull, the energy drink-maker who is sponsoring the feat, says that Baumgartner should reach the speed of sound within 40 seconds. From there, says the Associated Press, “he will start to slow as the atmosphere gets denser, and after five minutes of free fall, he will pull his main parachute. The entire descent should last 15 to 20 minutes.”

The daring leap will take place just a week shy of the 65th anniversary of a human first breaking the sound barrier, a feat achieved by Charles “Chuck” Yeager in the experimental Bell X-1 over the sands of California on October 14, 1947.

The AP says that NASA is “paying close attention” to the program. So too is the military, says the Los Angeles Times. The specialized suit worn by Baumgartner could be useful should future astronauts or pilots need to make a high-altitude escape from a crippled craft. Baumgartner’s custom suit will provide oxygen and water, will keep him safe against the thin atmosphere and will “protect him from temperatures ranging from 100 degrees Fahrenheit to -90 degrees Fahrenheit.” And, through a bevy of mounted cameras, the whole spectacle will be streamed live online.

*This story originally said Monday, October 8. The Red Bull Stratos team just announced via their Twitter account that the jump will be postponed by a day

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