Skydiver Felix Baumgartner smashed a number of records with his “edge of space” stunt – including for live streaming.
More than eight million people flocked to their devices to watch the 43-year-old break the speed of sound live on Google’s YouTube site.
It is the largest number of concurrent live streams in the website’s history, Google confirmed.
Austrian Felix Baumgartner also broke the record for the highest freefall.
He jumped from a capsule taken to 128,100ft (24 miles; 39 km) above New Mexico in the US by a giant helium balloon.
It took nine minutes for him to reach the ground.
The adventurer plummeted at an estimated 833.9 mph (1,343 km/h), hitting Mach 1.24.
“On the step, I felt that the whole world is watching,” Felix Baumgartner said after the jump.
“I said I wish they would see what I see. It was amazing.”
More than eight million people flocked to their devices to watch Felix Baumgartner break the speed of sound live on YouTube
The capsule from which the skydiver fell was equipped with cameras to provide a live internet feed to millions of people around the world.
A Google spokesperson confirmed that the number of viewers simultaneously watching the Red Bull Stratos stunt live on YouTube was the site’s highest.
“We congratulate Felix Baumgartner and the entire Red Bull Stratos team for their successful mission, and for creating a live stream with the most concurrent views ever on YouTube,” the company said on its blog.
In comparison, about 8.3 million people accessed the BBC’s sport website on the first day of this year’s Olympic Games.
Other technology used to record the event will have a more long-term application. Felix Baumgartner’s body was monitored during the jump using equipment from Equivital, a small UK company.
A system strapped to the skydiver’s chest wirelessly transmitted data about his heartbeat, respiration, skin temperature and other vital signs.
“It’s a major coup for Equivital, which, despite its small size – currently only 25 employees – provides the US Army with its human body monitoring system,” the company said.
The Red Bull Stratos scientists said the stunt had provided invaluable data for the development of high-performance, high-altitude parachute systems, and that the lessons learned would inform the development of new ideas for emergency evacuation from vehicles, such as spacecraft passing through the stratosphere.
“Part of this programme was to show high-altitude egress, passing through Mach and a successful re-entry back [to subsonic speed], because our belief scientifically is that’s going to benefit future private space programmes or high-altitude pilots, and Felix proved that today,” said Art Thompson, the team principal.
Felix Baumgartner has lifted off on his mission to break a series of freefall records.
Austrian skydiver’s giant helium balloon left the ground at Roswell, New Mexico, a short while ago and is currently on a climb that should take it to more than 120,000 ft (36.5 km).
Felix Baumgartner will then jump out.
The near absence of air at this high altitude means he should break the speed of sound as he falls – a velocity in excess of 690 mph (1,110 km/h).
The journey down should take 10 minutes, about half of it in freefall.
No-one has ever gone so high in a balloon, nor attempted to make such a high skydive.
The current record for the biggest jump of all time is now 52 years old. It was set by US Air Force Col. Joe Kittinger when he leapt from a helium envelope at an altitude of 102,800 ft (31.3 km).
There are immense risks involved in what Felix Baumgartner is trying to do.
Felix Baumgartner has lifted off on his mission to break a series of freefall records
Where he is going, the air pressure is less than 2% of what it is at sea level, and it is impossible to breathe without an oxygen supply.
Others who have tried to break the existing records for the highest, fastest and longest freefalls have lost their lives in the process.
Engineers have done everything possible to limit the risks. They have built the Austrian a special pressurized capsule to carry him aloft under the helium balloon.
He will also be wearing a next-generation, full-pressure suit, an evolution of the orange protective clothing worn by shuttle astronauts on launch.
Although the jump has the appearance of another Felix Baumgartner stunt, his team prefers to stress its high scientific relevance.
The researchers on the Red Bull Stratos project believe it will inform the development of new systems for emergency evacuation from high-performance, high-altitude vehicles. NASA and its spacecraft manufacturers have asked to be kept informed.
There are a few examples of pilots being ejected in supersonic airflows when their planes broke apart in the sky, but there is no detailed data on what happens to the human body as it goes supersonic and then, as it slows, goes subsonic again.
Felix Baumgartner will be instrumented to acquire this new data.
Engineers have incorporated an automatic device in his gear that would deploy a drogue stabilization chute if he gets into trouble.
There is, however, high confidence in Baumgartner’s team that he will complete the task ahead of him. He has been buoyed by the success of two practice jumps that have taken him progressively higher into the stratosphere – from 71,600ft (21.8km) and 97,100ft (29.6km).
The official lift-off time for the balloon was 09:31 MDT (16:31GMT). Mission control at Roswell airport is following every moment of what is likely to be a more than two-hour ascent to the jump altitude.
Baumgartner is in video and radio contact throughout. The only person who will speak to him, however, is Col. Joe Kittinger, who was brought into the team early to advise the Austrian how best to beat the octogenarian’s records.
“We are going to get your goal and your dream accomplished Felix,” Joe Kittinger told Felix Baumgartner just before lift-off.