Base-jumping Austrian to break sound barrier – if he can take off

In a world that has been comprehensively conquered from Pole to Pole, where younger explorers successfully scale our tallest peaks each year, and where satellites have mapped every last square kilometre of our planet, there are few truly outrageous challenges left to overcome.

Fortunately for fans of ludicrous feats there are people like Felix Baumgartner. A former member of the Austrian special forces, Baumgartner has made a name for himself in the highly dangerous world of base jumping – the sport of launching oneself off buildings with just a single parachute to bring you safely back to earth.

The Tapei 101 in Taiwan, Rio de Janeiro's Christ the Redeemer statue and Kuala Lumpur's Petronas Towers are just some of the structures that the 41-year-old has become the first person to conquer.

All of which are just a walk in the park compared with his next project – launching himself out of a helium balloon 23-miles above the earth's surface. It is a bid which, if successful, would set a new record for the highest parachute jump and could see Baumgartner becoming the first man to break the sound barrier without any form of propulsion.

The jump was slated to take place at a secret location next month in New Mexico. But a lawsuit in the States has brought the Austrian daredevil crashing back to earth.

While scientists were putting the finishing touches to the pressurised suit needed for his jump, a promoter was filing a lawsuit claiming Red Bull – the company behind the skydive – had stolen his idea. According to a writ in Los Angeles Superior Court, Daniel Hogan claims he pitched the idea for a space dive to Red Bull in 2004. He claims the energy drinks company feigned interest, only to come up with its own version four years later. Mr Hogan claims the stunt would have been worth up to $625m (£390m) in advertising to any corporate sponsor.

Baumgartner intends to begin his space dive at 120,000 feet. It's not quite true space, which officially starts at 62 miles up (327,360 feet), but it is still a dangerous place to start a skydive.

On any normal dive, jumpers rarely descend above a velocity of around 120mph thanks to air resistance. At 23 miles up Baumgartner expects to break the 768mph sound barrier – he will know when his body emits a sonic boom.

But speed is the least of his problems. Should his body go into a spin greater than 180 rotations per minute his brain is likely to be liquidised by super-pressurised blood rushing to his head. His suit should emit a corrective parachute if that happens but no one really knows if it will work.

Red Bull has now postponed the attempt until the lawsuit is resolved.

When asked whether he feared dying during the jump, Baumgartner reportedly said: "I could die in my sleep."