ROSWELL, New Mexico, July 24, 2012  -- It seems appropriate that Roswell, ground zero for UFO hunters, is hosting the mission to the edge of space -- because the sight of daredevil Felix Baumgartner diving back to Earth from 90 thousand feet will certainly spark new UFO conspiracy theories.

Baumgartner will go from zero to perhaps 509 mph in 30 seconds when he finally jumps from his space capsule. (An attempt was scrubbed Tuesday morning because of high winds; another try could be made Wednesday.) He hit 365 mph when he jumped from 71,000 feet in March -- and he is expected to go supersonic in August when he dives from 120,000 feet.

That's zero to 690 mph in 25 seconds -- a human body breaking the sound barrier without an airplane. Most people go to the edge of space or beyond in a rocket; Baumgartner is going up in a capsule carried aloft by a huge helium balloon.

Click Here for Pictures: Felix Baumgartner's Dive

Most of us would never willingly step out of a moving plane at any altitude. So you have to wonder why Felix Baumgartner does this. He says he knows the risks and accepts the danger.

"The pressure is huge, and we not only have to endure but excel," he said. "We're excellently prepared, but it's never going to be a fun day, I'm risking my life, after all."

Red Bull is financing this daredevil skydive from space. The mission is named Stratos. Five years of planning by a team of experts, many volunteering their services, to break several records in one breathtaking plunge back to Earth:

First person to break the sound barrier outside of an aircraft.

Record for freefall from the highest altitude

Longest freefall time –expected five minutes 35 seconds.

Highest manned balloon flight.

This daredevil dive from near space is not a first. The Austrian Baumgartner will be breaking a 52-year-old record if he succeeds, and he wisely recruited the man who set the record, the legendary Air Force Col. Joe Kittinger, for advice. On Aug. 16, 1960, Kittinger jumped from a balloon at an altitude of 102,900 feet -- and fell for almost five minutes before opening a parachute to slow his descent at 18,000 feet. He made history for the highest balloon ascent, the highest parachute jump, and the fastest speed by a human being through the atmosphere.

"Somebody will beat them someday, but when they do it, they'll be doing it to beat a record," Kittinger said in a 2008 interview with ABC's Jonathan Karl. "We didn't make those records at the time just for that purpose"

He now says he is happy to cede his record to Baumgartner -- but joked, "I told him if he changes his mind, I am ready to take over for him."

Dr. Jonathan Clark, a former NASA flight surgeon now with the National Space Biomedical Research Institute, heads the medical team monitoring Baumgartner's jump, ready to respond in an emergency. "We have run hours of tests in vacuum chambers, we are finessing life support systems, and monitoring his systems during the dive, calculating what he will need during the plunge back to Earth to survive," he said.

It is dangerous. Every member of the team acknowledges the risks. Clark said he can tick them off in his sleep: the near-vacuum of space, extreme cold, temperature fluctuations, the danger of an uncontrolled flat spin, drogue chute failure, spacesuit puncture, life support systems failure.

Is this a stunt? Clark scoffs at the suggestion. It is a scientific endeavor for him. His wife Laurel was one of the seven astronauts on the space shuttle Columbia when it broke up over Texas in 2003. A spacesuit like the one designed for this mission he said, might have saved her life.

"What the Red Bull Stratos does for me in some way is justify the loss of the of the Columbia crew," said Clark, "because it has pushed us to say we will never give up, we will always try to bring an un-survivable situation into a survivable realm. So for me this is personally important. It could lead to better crew escape systems. "

Weather is critical because the massive balloon is fragile and tears easily; it can't launch with winds in excess of 4 mph or under heavy cloud cover. Meteorologist Don Day also needs to consider where winds will push Baumgartner when he lands -- preferably not in the mountains west of the launch site.