Baumgartner: 'I was close to saying - get me out'
2 November 2012 Last updated at 10:46 GMT
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 the edge of space and his freefall almost put the whole project in jeopardy.
One of the team's biggest fears was that Baumgartner's suit would fail above the Armstrong limit - the altitude that produces an atmospheric pressure so low (0.0618 atmosphere) that water boils at the normal temperature of the human body.
Part of his training was done on the ground in a pressure chamber - an experience he found very challenging.
Space Dive is broadcast on BBC Two on Sunday 4 November at 20:30 GMT or watch online afterwards.