happylight Wrote:The speed needed to reach Mach 1 is lower at high altitudes though. 343.2 m/s is at sea level.
That has no bearing, since what they are saying is that he reached a maximum speed of 834mph (372.8 m/s) which is Mach 1.08 when considering Mach 1 = 343.2, that's still higher than what I've shown to be the maximum speed he could have had. The point at which he reached the higher numbers of Mach was most likely just before he opened his parachutes, at not so high of an altitude.
EDIT: So I've read some more on the story and found something that actually breaks my theories: he would have reached his top speed way before he opened his parachutes. Actually, there is a point of maximum speed while he's still at very high altitudes and after that the increasing viscosity of the atmosphere actually generates enough drag force to slow him down. Meaning that my supposition that his downwards acceleration was always positive is actually wrong.
If I still want to disprove the story I'd have to calculate the actual speed profile using the physical properties of the air at different altitudes (pressure and temperature taken into account) and estimate a drag coefficient. I'll have to take out my Unit Operations book.