The man who's going to jump 23 miles to Earth this week: Dubbed Fearless Felix, this extreme skydiver will try to break the sound barrier free-falling from space 
 
 One tiny error could result in his blood boiling and his brain exploding 
 
 Austrian Felix Baumgartner has spent five years planning the daredevil feat 
 
 He will be attempting to break the sound barrier on Tuesday leaping from an aircraft on the edge of space in a pressurised suit with a parachute 
 
 
 
 
 
 Should anyone else be planning the feat Felix Baumgartner will undertake on Tuesday morning, this weekend would be a time of sleepless nights and dread-filled days. 
 
 
 
 For 23 miles up on the edge of space, and wearing only a pressurised suit and a parachute, he will pause at the hatch of his tiny capsule as it ascends into the heavens beneath one of the biggest balloons ever made. 
 
 Red Bull Stratos announced Friday that the jump by extreme athlete Felix Baumgartner have been moved from Monday to Tuesday thanks to a cold front with gusty winds. The jump can only be made if winds on the ground are under 2 mph for the initial launch a balloon carrying Baumgartner. 
 
 Fearless: Felix, pictured here on a previous dive in July, plans to jump from the edge of the earth's atmosphere on Tuesday 
 
 No more than 20 minutes later, the world will know whether this audacious Austrian has become the first skydiver to break the sound barrier in the highest, fastest freefall descent in history. 
 
 If anything goes wrong — and despite five years of planning and training, there is plenty that could — it might get very, very messy. 
 
 
 
 The nightmare scenario that Felix’s project director likens to a ‘horror film’ would involve his blood boiling, brain bursting and eyeballs popping out — all of it watched live via the internet around the globe. 
 
 This may sound like the sort of lunatic feat that no one but a man who has spent 20 years at the more extreme end of extreme sports would want anything to do with. But a team of engineers, doctors and pilots have spent five years working alongside Baumgartner, 43, to ensure he gets down alive and in one piece. 
 
 For one of them, Dr Jonathan Clark, the operation’s medical director, there is an intensely personal reason for being involved. 
 
 
 
 Since his astronaut wife Laurel was killed in 2003 when the space shuttle Columbia disintegrated over Texas, the former Nasa flight surgeon has devoted his career to working to improve astronauts’ chances of surviving a similar high-altitude disaster. 
 
 Austrian Felix Baumgartner, pictured at a news conference in New York, will leap from an aircraft 23 miles above New Mexico, in an attempt to jump higher and faster in a free fall than anyone ever before 
 
 ‘I have every expectation he’ll come through this successfully,’ says Dr Clark. ‘But, you know, it is still an unknown.’ 
 
 As for Baumgartner, quite the Hollywood action man with his rugged good looks and Born To Fly tattooed on his arm, he and his backers are sufficiently confident that they are filming the descent and streaming it on YouTube. 
 
 
 
 Banishing talk of nerves, he says he would never jump if the odds were against him. And he insists he hasn’t got a death wish. 
 
 Of the sceptics who will be holding their hands in front of their eyes as he hurtles towards Earth at nearly 700mph, he says simply: ‘I think they underestimate the skills of a skydiver.’ 
 
 Fearless Felix has been flinging himself out of planes and off skyscrapers for years. He has clocked up 2,500 skydiving jumps, including one in which he became the first person to ‘fly’ across the English Channel, with carbon-fibre wings strapped to his back. He has performed various horrifying ‘base jumps’, freefalling off the Christ statue in Rio and leaping head-first into a pitch black, 620ft-deep cave in Croatia. 
 
 Baumgartner says his supersonic plunge will be the end of his ‘journey’ as a daredevil. He intends to retire with his girlfriend and settle down to a quiet life — which in his case means becoming a rescue helicopter pilot. 
 
 Ahead of his grand finale, he has completed a couple of high-altitude dress rehearsals. In July, he leapt from 96,640ft — just 6,000ft shy of a world record set in 1960 by Joe Kittinger, a U.S. air force test pilot. 
 
 The grandfather of stratosphere skydiving, 84-year-old Colonel Kittinger has become Baumgartner’s mentor and will be the voice he hears in his headset as he communicates with mission control before and during the jump. 
 
 Fearless Felix, pictured saluting as he prepared in March to board a capsule carried by a balloon during the first manned test flight for Red Bull Stratos in Roswell, New Mexico 
 
 But a disembodied voice will not protect him against some of the most extreme forces in nature. 
 
 ‘You can feel in your stomach and every part of your body that it does not want to be there,’ says the Austrian, a former military parachutist, laconically. 
 
 The body in question will be encased in a specially designed £125,000 spacesuit. It has an insulating exterior that can withstand extreme temperatures, and an airtight inner layer filled with pressurised oxygen. 
 
 It also has one crucial difference to the spacesuits worn by astronauts, which is that it remains highly flexible when it is fully pressurised. 
 
 Baumgartner’s visor is fitted with an intensely powerful heat regulator that should keep his view free of fog and frost. 
 
 The suit’s 12lb chest pack contains monitoring and tracking equipment together with a voice transmitter so he can talk to mission control on the way down. The pack is connected to a device on his wrist that allows him to monitor his speed and altitude. 
 
 The capsule in which he’ll make his ascent is 11ft high and 8ft in diameter, made from fibreglass strengthened by an internal metal frame, and weighs as much as a Volkswagen Beetle. 
 
 The Red Bull Stratos science team has confirmed that the capsule delivering Austrian sportsman Felix Baumgartner to the edge of space for his record-breaking free-fall attempt is mission ready 
 
 It was designed by some of the scientists who created the U.S. stealth bomber and is based on the famous Nasa Apollo rocket, but with a few key design differences. 
 
 The exit hatch is bigger for a start, designed to prevent the sort of catastrophe that befell Soviet high-altitude sky diver Pyotr Dolgov in 1962. Struggling to leave his capsule in his cumbersome spacesuit, Dolgov cracked his visor slightly on the door. 
 
 He was dead by the time he landed, a victim of ebullism, the terrifying condition in which the drastically lower air pressure above 62,000ft makes liquids in the body start to bubble and vaporise, inflating the body and bringing unconsciousness within 15 seconds. 
 
 Unfortunately for Baumgartner’s sponsor, Red Bull, he won’t be able to consume any of the fizzy energy drink on the way up. 
 
 The air pressure inside the capsule will still be significantly lower than at sea level, and any kind of gas inside his body could prove extremely uncomfortable. The Austrian company won’t say how much it has sunk into the project, but it must surely run into millions. 
 
 Pilot Felix Baumgartner did his first test jump from the Red Bull Stratos capsule in March, in which he reached an altitude 21,800 meters (71500 ft) and landed safely near Roswell, New Mexico 
 
 Weather permitting (the balloon material is so flimsy the ground level wind cannot be stronger than 2mph), the launch is scheduled for dawn on Tuesday, on a runway in the New Mexico desert. 
 
 A ten-strong team wearing cotton gloves and protective suits to prevent them ripping the fabric will pump helium from two large lorries into a £150,000 balloon that has been hailed as the biggest ever to lift a passenger. 
 
 When inflated, it is as high as a 55-storey building with a volume of 30 million cubic feet. 
 
 Made from strengthened plastic, it is a tenth of the thickness of a sandwich bag. Baumgartner has limited space to move around in the capsule and the balloon will be largely steered remotely from mission control down on the ground. 
 
 If all goes well, the journey will take just under three hours. The biggest danger he faces on the way up is the risk of the balloon rupturing soon after take-off. If that happens, Fearless Felix won’t have time to open the hatch and get out, and will come crashing down inside the capsule. 
 
 When it reaches the jumping height of 120,000ft — three times the altitude at which airliners fly — he will look out on a black rather than blue daytime sky while he waits for the final ‘clear to jump’ message from mission control. 
 
 Pictured in the capsule that he will launch himself from on Monday, Felix looks more like an astronaut than a sky-diver, fully equipped with a space suit and high-tech equipment 
 
 At that point, he will depressurise the capsule, pressurise his suit and open the exit door (the capsule will later automatically detach from the balloon and parachute back to Earth). 
 
 It’s a virtually oxygen-free vacuum up there, with just one per cent of the air pressure on Earth, so the consequences of an accident now — a ripped suit (the biggest fear) or hairline helmet crack — would be disastrous, bringing on the dreaded ebullism in seconds. 
 
 If that isn’t bad enough, a spacesuit failure could also bring on the bends (gas seeping into body tissues due to sudden low pressure), barotrauma (trapped gas in body cavities that can collapse the lungs), and severe oxygen deprivation, known as anoxia. 
 
 And let’s not forget the discomfort of falling through air with a temperature as low as minus 70f. 
 
 Even leaving the capsule is fraught with danger. Baumgartner, who will basically fall forwards off the capsule platform, needs to start plunging straight down and head first as quickly as possible to reach maximum speed. 
 
 But there is always a risk that, with virtually no wind at those altitudes, he could end up in an uncontrolled flat spin. 
 
 At such high altitude, Fearless Felix will be able to see the curvature of the Earth and will free-fall for 20 minutes before landing 
 
 In his test jump in March, Felix plunged 25,000 feet. Tomorrow he hopes to jump higher and faster in a free fall than anyone ever before 
 
 And if he spins too fast, the force will make him lose consciousness, cause brain damage, turn his eyeballs into reddish-purple orbs and — very possibly — kill him. 
 
 As a safety precaution of sorts, his clever spacesuit will release a drogue parachute — a miniaturised version of the type used to slow fast-landing jets — to reduce his speed if its monitoring system senses he has lost consciousness. 
 
 It will take him just 40 seconds to go from zero to 700mph and break the sound barrier at an altitude of around 100,000ft. 
 
 No one can be sure what happens when a body breaks the sound barrier at that height, and the possibility of his suit being damaged by supersonic shock waves is another unpleasant ‘what if’ that Baumgartner’s scientific experts have had to consider. 
 
 Felix, left, will be guided by U.S. Air Force Col. (Ret.) Joe Kittinger, right, who holds the current stratospheric jump record, from 1960 of 102,800 feet 
 
 But once he has gone supersonic, travelling at the speed of a bullet, the air resistance will start to pick up as the atmosphere becomes more dense and he can move himself into the more stable ‘delta’ position — arms and legs spread out, body parallel to the ground — that you normally see being used by skydivers. 
 
 Assuming he makes it through intact, Baumgartner, his spacesuit fitted with cameras recording his stomach-churning descent, will freefall for some five-and-a-half minutes before pulling his main parachute at 5,000ft. Some ten to 15 minutes later, with luck he will touch down battered but unbowed near Roswell. 
 
 The remote New Mexican town is, of course, famous for a rumoured UFO crash landing in 1947. 
 
 How wonderfully apt. Where else can claim to have had stranger things drop out of the sky than Fearless Felix? ||||| Extreme athlete Felix Baumgartner canceled his planned death-defying 23-mile (37.01-kilometer) free fall Tuesday because of high winds, the second time this week he was forced to postpone his quest to be the first supersonic skydiver. 
 
 FILE - 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 Monday, Oct.... (Associated Press) 
 
 In this Feb. 23, 2012 photo provided by Red Bull Stratos, pilot Felix Buamgartner of Austria shows a piece of the balloon material during the Red Bull Stratos egress training in Lancaster, Calif. It’s... (Associated Press) 
 
 In this July 25, 2012 photo provided by Red Bull Stratos, a balloon lifts up during the second manned test flight for Red Bull Stratos in Roswell, N.M. It’s described as a “40-acre dry cleaner bag,” that,... (Associated Press) 
 
 Felix Baumgartner, in pressurized suit on platform at left, prepares to enter the balloon capsule in Roswell, N.M. on Tuesday, Oct. 9, 2012. Baumgartner will attempt to break the speed of sound with his... (Associated Press) 
 
 The former military parachutist from Austria had planned to ride a pressurized capsule carried aloft by a 55-story, ultra-thin helium balloon into the stratosphere, and then jump in a specially designed suit. 
 
 But winds and delays from a lost radio and problems with the capsule contributed to the decision shortly after 11:30 a.m. to abort the mission. Because the balloon is so delicate, it could only take flight if winds were 2 mph or below. 
 
 Baumgartner said he will try again. It was unclear if that would come this week. 
 
 Baumgartner, 43, was suited up and in the capsule, when a live online video feed of the mission showed winds kicking up and whipping the balloon around. Baumgartner later got out of the capsule and was in his trailer. 
 
 The plans to launch were in question before sunrise, when winds at 700 feet (213 meters) above ground _ the top of the balloon _ were 20 mph (32 kph), mission organizers said. 
 
 The balloon had been scheduled to launch about 7 a.m. from a field near the airport in a flat dusty town that until now has been best known for a rumored 1947 UFO landing. 
 
 Baumgartner was to make a nearly three-hour ascent to 120,000 feet (36,576 meters), then take a bunny-style hop from the capsule into a near-vacuum where there is barely any oxygen to begin what was expected to be the fastest, farthest free fall from the highest-ever manned balloon. 
 
 Among the risks: Any contact with the capsule on his exit could have torn the pressurized suit. A rip could have exposed him to a lack of oxygen and temperatures as low as 70 degrees below zero. It could have caused potentially lethal bubbles to form in his bodily fluids, a condition known as "boiling blood." 
 
 He could also have spun out of control, causing other risky problems. 
 
 The energy drink maker Red Bull, which is sponsoring the feat, had been promoting a live Internet stream of the event at http://www.redbullstratos.com/live from nearly 30 cameras on the capsule, the ground and a helicopter. But organizers said there will be a 20-second delay in their broadcast of footage in case of a tragic accident. 
 
 And while Baumgartner hopes to set four new world records when he jumps, his free fall is more than just a stunt. 
 
 His dive from the stratosphere should provide scientists with valuable information for next-generation spacesuits and techniques that could help astronauts survive accidents. 
 
 Jumping from more than three times the height of the average cruising altitude for jetliners, Baumgartner expects to hit a speed of 690 mph (1,110 kph) or more before he activates his parachute at 9,500 feet (2,895 meters) above sea level, or about 5,000 feet (1,524 meters) above the ground in southeastern New Mexico. The total jump should take about 10 minutes. 
 
 His medical director is Dr. Jonathan Clark, a NASA space shuttle crew surgeon who lost his wife, Laurel Clark, in the 2003 Columbia accident. No one knows what happens to a body when it breaks the sound barrier, Clark said. 
 
 "That is really the scientific essence of this mission," said Clark, who is dedicated to improving astronauts' chances of survival in a high-altitude disaster. 
 
 Clark told reporters Monday he expects Baumgartner's pressurized spacesuit to protect him from the shock waves of breaking the sound barrier. If all goes well and he survives the jump, NASA could certify a new generation of spacesuits for protecting astronauts and provide an escape option from spacecraft at 120,000 feet, he said. 
 
 Currently, spacesuits are certified to protect astronauts to 100,000 feet (30,480 meters), the level former Air Force Capt. Joe Kittinger reached in his 1960 free-fall record from 19.5 miles (31 kilometers). Kittinger's speed of 614 mph (988 kph) was just shy of breaking the sound barrier at that altitude. 
 
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 Follow Jeri Clausing at http://twitter.com/jericlausing.
– Felix Baumgartner has already sky-dived from 13 miles up and 18 miles up—so what's a leap of 23 miles that shatters the sound barrier? Well, it at least requires good weather, so the record-breaking dive has been bumped from Monday to Tuesday to avoid strong winds and rain, Space.com reports. Then the 43-year-old Austrian will ride a specially designed capsule into the stratosphere and take a leap over southeastern New Mexico. The key for Baumgartner is to jump head-first and reach maximum speed so as to avoid an uncontrolled flat spin—which could cause brain damage and possibly kill him, the Daily Mail reports. Within 40 seconds he hopes to reach 700mph, and hit the speed of sound at around 100,000 feet. Ultimately he intends to land near Roswell. His plan after completing the feat: retire and enjoy a quiet life, which for him means working as a rescue helicopter pilot.