Skydiver to jump from 25 miles up

The Sunday Times (UK) ^ | October 21 2001 | Paul Ham, Sydney

[fnord]

bump

[Henry F. Bowman]

Regarding that supersonic speeds are slower at higher altitudes, it still remains that the body will be traveling awfully fast before it starts slowing down.

Assume vacuum for the first 60,000 feet fall from 120k to 60k altitude. height= 1/2*a*t^2. a=32ft/sec^2. Thus, the time spent dropping from 120k feet to 60k feet is about 43 seconds. Multiply by the acceleration of 32 ft/s^2, and you get 1387 feet per second, or 945 mph. Of course, that assumes a vacuum, so the number may be lower, but we are at a velocity about mach 2 at sea level.

Fast!

[peabers]

Activate the Darwin Awards mobile team for a possible nominee filming.

He's been working on this project for over two years with NASA, the Australian Defense Forces and the US military. It's anything but an attempt to win a Darwin.

[HeadOn]

I stand corrected - forgive me, I'm old and rusty. But still, as soon as he jumps, really, he's "supersonic". I don't think I'm up to that kind of speed.

[paul51]

If it's vacuum, how does the balloon get him up there?

[ArrogantBustard]

If it's vacuum,

What's a vacuum? Seriously. The air pressure might be just a few mm Hg, not nearly enough to breathe, but enough to float a balloon. The balloon will be huge at its target altitude in order to compensate for the very low density atmosphere.

AB

[rogers21774]

Rodd Millner, 37, hopes to freefall for six minutes before opening his parachute and touching down within 30 miles of Ayers Rock in central Australia.

That averages out to about 250 mph. You know that in the first 30,000 ft or so he'll probably be traveling about twice that speed. Cool!

[Zack Nguyen]

Thanks for your help!

[paul51]

I get it. Thanks.

[buckman10_2000]

they'll probably end up in his throat,since his head will explode anyway.