Why Baumgartner's record dive almost didn't happen
Austrian Felix Baumgartner is the first skydiver to go faster than the speed of sound - but a severe claustrophobic reaction to the pressure suit he had to wear during his ascent to 39km (24 miles) and his freefall almost put the whole project in jeopardy.
The 43-year-old adventurer had never worked at extreme altitude before, and in order to survive the jump he needed to be more than a skydiver - he needed to become a test pilot.
His next generation, full pressure suit was made by the same company that prepares the flight suits of astronauts - but whereas a test pilot would have a couple of thousand hours to train in a pressure suit, Baumgartner only had 20.
A BBC/National Geographic documentary about the project reveals how much he struggled during the four years of training.
"Having this suit on my body and feeling it, and the smell of the rubber, made me anxious," he said.