In this Thursday, March 15, 2012 photo provided by Red Bull Stratos, Felix Baumgartner prepares to jump during the first manned test flight for Red Bull Stratos over Roswell, N.M. On Tuesday, Oct. 9, 2012 over New Mexico, Baumgartner will attempt to jump higher and faster in a free fall than anyone ever before and become the first skydiver to break the sound barrier. (Jay Nemeth/AP)

UPDATE, 1:43 p.m.: Mission aborted due to gusty winds. Not clear when will be rescheduled. Live video says Felix Baumgartner “disappointed.”

UPDATE, 1:25 p.m. Tuesday (11:25 a.m. MDT): Launch time may be closer to 11:35 a.m. (MDT) based on current indications. Baumgartner has entered the capsule. Watch the live broadcast here.

UPDATE, 1:10 p.m. Tuesday (11:10 a.m. MDT):

The Stratos team reports improved wind conditions, with Baumgartner’s official launch now scheduled for 11:15 a.m. (MDT).

UPDATE, 10:00 a.m. Tuesday:

Red Bull Stratos has announced a weather hold due to winds aloft, with a possible launch at 11:30 a.m. (MDT) today.

Original post (from Monday morning): Skydiving from 23 miles above Earth is certainly not for the faint of heart. That’s what 43-year-old Austrian daredevil Felix Baumgartner will set out to accomplish this Tuesday morning (Oct. 9).

With only a pressurized spacesuit and a parachute, Baumgartner hopes to become the first person to break the speed of sound during free fall. If successful (i.e. survives), he will set a new record for the highest and fastest human free fall in history.

Dubbed “Fearless Felix,” Baumgartner has spent five years training for this immense leap of faith. A giant helium-filled balloon will enable Baumgartner’s space capsule to take off from the New Mexican desert shortly after dawn on Tuesday (Red Bull, his sponsor, delayed the mission by 24 hours due to gusty winds from a nearby cold front).

After liftoff, it will take nearly three hours for Baumgartner to ascend to 120,000 feet above Earth – three times higher than the cruising altitude of commercial aircraft. Upon exiting his mission capsule, Baumgartner will jump head first, testing the limits of scientific knowledge as he flies toward Earth at supersonic speeds of 690 mph (Mach 1).

Video: How was Felix’s parachute designed? (Red Bull)

Baumgartner will reach the speed of sound in less than a minute and continue in free fall for five whole minutes before he opens his parachute at 5,000 ft. If all goes according to plan, he will be back on solid ground in 20 minutes.

Simulation of jump on Red Bull’s YouTube channel

But that’s a big if. Any mishap or equipment failure would mean instant death. Air temperatures in the stratosphere will be as low as -70ºF and air pressure less than 1 percent of what it is on Earth. A crack in his bodysuit would, among other things, cause his lungs to overinflate and his blood to boil. Another concern is that Baumgartner could fall into a flat spin, in which he loses control of his body and enters into an unconscious death spiral.

In this Friday Jan. 22, 2010 photo provided by Red Bull Stratos, Pilot Felix Baumgartner, left, shakes hands with United States Air Force Col. (Ret.) Joe Kittinger, right, following the Red Bull Stratos press conference in New York announcing Baumgartner's plan to attempt to become the first person ever to break the speed of sound with the human body. (David Goldman/AP)

What happens if Baumgartner does survive to set a new record? The Austrian skydiver says he plans to finally retire “because I’ve been successfully doing things for the last 25 years, and I’m still alive.”

Good call, Felix.

Watch the countdown clock and learn more about Baumgartner’s Red Bull Stratos mission on their website. The jump will be broadcast live from around the world – get the full list of news sources here.