An adventurer planning the highest sky dive in history says he will make the record attempt later this year.
Felix Baumgartner will jump from a balloon, 23 miles up in the air - that would take 45 minutes to drive by car at normal speed!
It's so high, he needs pressurised suit - and if that broke, his blood would vapourise.
If it works he'll become the first person to go faster than the speed of sound unaided by a machine.
Many have tried to achieve this feat but all have failed. He said the last test before he goes on the jump had been successful.
"It means I can deliver, I can perform. The equipment will function," he said.
The suit is similar to those worn by astronauts but it has to be tougher than a Nasa space suit to keep him safe from the air pressure, and provide him with oxygen to breathe.
It will also have to protect him from the extreme temperatures of minus 70C.
If the attempt succeeds, it will be the first time the record has been broken for over 50 years.