[agumonkey]

On the live stream they said he topped 1173km/h. What speed was the target ? I mean speeds are defined in air and 'normal condition', there was almost no gas around him during his fall right ?

[izend]

Speed of sound has a non-linear relationship with altitude.

http://www.wolframalpha.com/input/?i=speed+of+sound+at+10000...

[jonmrodriguez]

With altitude. Non-linear with attitude would mean w/ angle of attack, which would be fascinating.

[Lapsa]

1,236 kilometres per hour (768 mph)