Felix Baumgartner, better known as Fearless Felix, has broken the sound barrier during his daredevil jump from space and landed back on earth safely.

The 43-year-old Austrian skydiver plunged around 39 km (24 miles) after he stepped out of his balloon which was airborne in the earth's stratosphere above New Mexico.

The record-breaking skydive was watched online by over eight million people across the globe.

On touching down, Baumgartner fell on his knees and raised his hand in salute before he was hugged by his jubilant parents.

It took the balloon, which was fitted with a special launch platform, nearly two and a half hours to reach the stratosphere.

During the less-than-10 minute skyfall, Baumgartner sliced through the atmosphere at a speed of 1,342.8km/h (833.9mph), becoming the first skydiver to overtake the speed of sound.

Describing the moment when he was standing at a height of 128,000 ft, Baumgartner said: "Let me tell you - when I was standing there on top of the world, you become so humble.

"You don't think about breaking records anymore, you don't think about gaining scientific data - the only thing that you want is to come back alive. Sometimes you have to go up really high to see how small you are."

The records set by Baumgartner will not be official until they are approved by the Federation Aeronautique Internationale (FAI).

His world records include the highest altitude skydive (128,000 ft), the fastest fall (1342.8 kph) and the longest freefall without a parachute (119,846 ft). The parachute was used only during the last few thousand feet.

Baumgartner appeared to get into trouble soon early in his jump, his body flipping over and over rather than assuming the 'delta' position in which the body is rigid in the downward position, and the head is tilted back. However the vastly experienced diver quickly stabilised his fall.

The jump itself had been on the verge of cancellation as the heater inside the helmet, which is similar to the ones worn by astronauts, was not working properly.

"This is very serious, Joe. Sometimes it's getting foggy when I exhale. ... I do not feel heat," Baumgartner told retired US Air Force Col Joe Kittinger.

Kittinger, who holds the record for the highest freefall (102,800 ft) for nearly 50 years, was an integral part of Baumgartner's team.

"Felix did a great job and it was a great honour to work with this brave guy," said the octogenarian.

The mission was previously cancelled twice, primarily due to bad weather.