Slashdot Mirror
Skydiver To Break Sound Barrier During Free-Fall
Hugh Pickens writes "Over fifty years ago, American Joe Kittinger made history by leaping from a balloon at 102,800 ft, and although many have sought to repeat the feat, all have failed. Now, BBC reports that Austrian extreme sportsman Felix Baumgartner will try to break the long-standing record for the highest ever parachute jump, skydiving from a balloon sent to at least 120,000 ft, and it is likely that 35 seconds into in his long free-fall of more than five minutes, he will exceed the speed of sound — the first person to do so without the aid of a machine. 'No-one really knows what that will be like,' says Baumgartner. Although challenges in the endeavor include coping with freezing temperatures and ultra-thin air, a key objective for Baumgartner will be to try to maintain a good attitude during the descent and prevent his body from going into a spin and blacking out. 'The fact is you have a lot of different airflows coming around your body; and some parts of your body are in supersonic flow and some parts are in transonic flow. What kind of reaction that creates, I can't tell you,' adds Baumgartner."
I suspected, and breaking slashdot rules and reading TFA confirmed, that his suit is designed to automatically deploy the parachute at some failsafe altitude, even if he blacks out earlier.
Still plenty of room for things to go wrong, people manage to die doing perfectly ordinary parachuting from time to time; but probably more dramatic than dangerous.
If there's enough atmosphere to lift a balloon, there's enough atmosphere to transmit sound.
http://alternatives.rzero.com/
That bit about Superman falling for you? That was a dream. :)
http://alternatives.rzero.com/
Failed?!? How can you fail that? Throw yourself self off the balloon and miss the ground?
/greger
It's really going to hurt.
I'm just going to say... Best Darwin award EVER!
To go that fast, he will need to be extremely streamlined. Air becomes incompressible at supersonic speeds, so either his feet or head will need to handle the friction and stress created. I'd want a stability bar running the length of my body that my feet, legs, torso, shoulders, arms and head "clip" into.
To get out of that streamlined attitude is easy. To get out of it safely is a different matter completely. I'd want a way to release a trailing parachute, attached to my shoulders, to bleed off most of the speed. Perhaps down to 200 mph.
Slowing from 1200+ fps to 120 fps is a big deal and without extremely careful methods to retain something call static stability http://en.wikipedia.org/wiki/Longitudinal_static_stability and he will end up tumbling out of control, breaking limbs or worse.
Any way, I wanna watch. I hope he does the trailing smoke thing!
Isn't "terminal velocity" lower than the speed of sound?
Not true at all. He wants to exceed the speed of sound by falling quickly, but the dang balloon keeps lifting him up! If anything, it's actively working against him!
On a more serious note, which simple machines would you say make up a balloon? Is it a pulley? A wedge? A lever? A balloon is just hot air in a sack. Nothing machine-like about that, though I suppose the mechanism for generating hot air may involve a machine, but that's tangential.
Pretty good information about high-altitude skydiving here: Speed of a Skydiver
http://www.geoffreylandis.com
The Difference between a bad golfer and a bad skydiver? one goes *Whack*... "D@mn". the other goes "D@mn"...Whack.