NEW YORK - A skydiver leaping from the edge of space could smash the nearly 50-year-old record for highest jump ever later this year, and set a new one as the first person to go supersonic in freefall.

More than just a stunt, the team sponsored by energy drink company Red Bull noted their findings could help lead to escape plans during spaceflights.

Austrian skydiver Felix Baumgartner, who became the first person to cross the English Channel in freefall in 2003, will make the attempt using a nearly 2,500-pound (11,339-kg) pressurized capsule hoisted up to the edge of space by a single helium-filled plastic balloon some 600 feet (182 meters) wide. ?After a roughly three-hour-long flight to roughly 120,000 feet (36,576 meters) ? more than four times the height of Mt. Everest ? Baumgartner will rotate the capsule's four-foot-wide door off to one side, grab the hand rails on either side of the exit, and leap off.

With the leap, Baumgartner could potentially break the records for highest parachute jump, as well as longest and fastest freefall. His team expects him to reach supersonic speeds 35 seconds after he leaps, given how little air will hold him back in such near-vacuum conditions.

The current world record for highest jump was set on August 16, 1960, when U.S. Air Force Captain Joe Kittinger jumped from a balloon at an altitude of some 102,800 feet (31,333 meters).

"Hell no, I didn't hesitate," Kittinger recalled of his jump. "When it came time to jump, I was happy as hell to go, to go back to where it's friendly and fun. Earth is friendly and fun, and it's not friendly and fun at 20 miles up."

Baumgartner?s team plans make its jump attempt in 2010, but a final target date will be determined after a series of final tests are performed.

Risky record jump

Many have attempted to surpass Kittinger's achievement, but all failed, with New Jersey native Nick Piantanida dying in his 1966 try. Now Kittinger will help advise Baumgartner on his jump.

"The spirit of man has always tried to go higher, deeper, faster," Kittinger said.

Baumgartner will face extreme danger. For instance, the forces he will face nearing the speed of sound "we know with aircraft can break them apart," said project medical director Jonathan Clark. "We've never had a person break the sound barrier without the aid of a vehicle before, so we're dealing with some unknowns here." Still, he pointed out one known instance of a pilot surviving the destruction of a plane at three times the speed of sound, so survival is definitely possible.

The extremely thin air is also a threat. At 120,000 feet, the atmospheric pressure is so low ? just 0.2 percent that at sea level ? blood will boil. Above the so-called 'Armstrong line' of 63,000 feet (19,200 meters), Thompson explained that if Baumgartner opened up his suit or helmet, gases start escaping from the body. "It sounds melodramatic, but you start bleeding from your eyes," explained project technical director, Art Thompson.

To survive, Baumgartner will employ a modified version of airtight, fully pressurized spacesuits currently employed by NASA and the U.S. Air Force, with more flexible joints. This will let him bend to achieve the standard, belly-down skydiving position needed to slow down.

The super-low pressure Baumgartner faces can also lead to decompression sickness, known to underwater divers as the bends, which involves nitrogen bubbles forming in the body. To prevent this risk, he will breathe only pure oxygen during the flight as well as two hours beforehand to flush nitrogen out of his body. However, pure oxygen is naturally highly flammable, which means electronics on the suit have to be designed to minimize any risk of sparking whatsoever, with sensors working on millionths of volts instead of thousandths, for instance.

Another hurdle Baumgartner faces is uncontrolled spin, which could render him unconscious. If need be, he can deploy a five-foot-wide drogue parachute that would stabilize his flight. Sensors on the suit will constantly monitor his acceleration for warning signs of spinning, as well as checking on his heart rate and position, transmitting data to the ground team via a radio in a pack mounted on his chest.

Cold, long flight

Inside the capsule, Baumgartner will be exposed to as much as minus 140 degrees Fahrenheit (minus 95 degrees Celsius), so he will have heated foot-warmers and hand-muffs to keep his extremities warm, and his face shield can heat to keep it from fogging up. However, the researchers aren't just concerned with keeping him warm, but also in making sure he doesn't get too hot and sweaty.

"We have to be careful how we draw off the moisture, since we don't want it to turn into ice," Thompson said. "You could freeze yourself in the suit." Dehydration is also a major concern, as they want to prevent disorientation ? "not knowing when to pull the chute is a bad thing," he added ? as well as potentially catastrophic vomiting.

After freefalling for roughly six minutes, decelerating to some 120 mph (193 kph) just from air resistance, Baumgartner should open his parachute at roughly 5,000 feet (1,524 meters). After he lands, the ground team can remotely cut the capsule loose from the balloon and have it drift down on a triple cluster of parachutes, and a crush pad of corrugated fiberglass epoxy laminate on its bottom will cushion its fall.

Test jumps on tap

Two preparatory flights will be conducted at 65,000 and 90,000 feet (19,812 to 27,432 meters) to catch any problems that might arise. Currently Baumgartner is undergoing rigorous tests in the suit in vertical wind tunnels to simulate falling, as well as in extreme cold and in vacuum chambers. In the two or three days before launch, he will go on a "low-residue" diet to reduce any risk of problems should he need to relieve himself during flight.

Red Bull would not reveal how much they spent on the project, and while it said the project would launch this year from North America, it has not specified a date or launch site yet. This uncertainty depends partly on finding the ideal weather conditions for the flight. "We want a still, calm environment," Thompson explained. Although they hope Baumgartner lands near his launch site, "he could drift maybe 150 to 200 miles off," he added.

By proving that people can survive a jump from that speed and altitude, the project hopes to show that astronauts might achieve the same if they ever need to escape from a spacecraft.

"The lessons we hope to learn from this suit could help eventually be used for future applications in the Orion program," the successor to NASA's space shuttle, Thompson said.

"I didn't do it to set a record," Kittinger said of his jump. "I went to gather useful scientific data. Felix will do the same. And he'll do a great job."