The Baumgartner's skydive

Today, we will witness again another story of achievement.

Felix Baumgartner aims to make history today as the first person to achieve supersonic speed in freefall.
As if that weren't enough, he will be starting his descent from higher than anyone else has ever ascended in a manned balloon flight: 120,000 feet, or 23 miles above the Earth.
The daredevil's jump comes after years of preparation and delays, and replete with a full array of high-tech gear, from the 2,900-pound "space capsule" slung under a 550-foot-tall (at launch) helium balloon that will carry him aloft in an approximately 2-hour ascent, to the custom-made full-pressure suit that will protect him from the very real dangers of the thin and frigid air.
Sensors in a chest pack will log all the relevant data for vetting by the Federation Aeronautique Internationale, the body that governs air sports and aviation records. Gear in the pack includes GPS tracking device, inertia measurement unit, HD camera, and voice transmitter and receiver.
Baumgartner's team, Red Bull Stratos, is live-streaming the jump, which is taking place in the vicinity of Roswell, N.M. You can watch it in the video embed below.
Update at 6:20 a.m. PT: The start of the ascent has been delayed twice this morning because of winds. The team had first eyed a delayed launch no later than 7 a.m. PT, but has postponed it a second time -- this time to 10:30 a.m. PT, pending cooperative weather.

Update at 8:38 a.m. PT: The weather is looking favorable, and preparations are proceeding apace. "Countdown is officially back on. Felix is in his suit and expected launch at 11:15 am MDT," Red Bull Stratos just tweeted. (That's 10:15 a.m. PT.)
Update at 10:17 a.m. PT: Baumgartner is in the capsule and the ascent is about to begin.
Update at 10:43 a.m. PT: The jump has been aborted for today because of gusting winds.

The 43-year-old Baumgartner also will need to exercise some serious body control to get into the most streamlined position possible for his freefall, which is expected to last roughly 5 minutes, 35 seconds (which also would be a record, outdoing the existing mark by a full minute). It all starts with making a precise exit from the capsule -- something he has rehearsed over and over again -- and he won't have to wait long to hit his top speed.

"If calculations prove to be accurate, and Felix is successful in his attempts to control his position," the Red Bull Stratos site explains, "he will accelerate from standstill to the speed of sound -- that's 0 to approximately 690 miles per hour in 40 seconds or less."

Eventually, Baumgartner will deploy his parachute, at about 5,000 feet above ground, for the final part of his descent. To open that main chute safely, he'll have to have slowed to about 172 mph.

The mission will be well-documented. Here's the array of cameras, including five on Baumgartner himself, that will be recording the ascent and descent:
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