Felix Baumgartner set for skydive record attempt
9 October 2012 Last updated at 14:30 BST
Austrian skydiver Felix Baumgartner will attempt to become the first human to break the sound barrier unaided by a vehicle.
He is going to jump out of a balloon at more than 120,000ft (36.5km) above Roswell, New Mexico.
If Mr Baumgartner succeeds, he will also become the first person to have gone faster than the speed of sound without an aircraft.
Pallab Ghosh reports from Roswell, New Mexico.