Skydiver Felix Baumgartner Completes 17-Mile Dive

[Jamie B]

http://news.yahoo.com/skydiver-felix-baumgartner-completes-17-mile-dive-134525786--abc-news-tech.html

Daredevil Felix Baumgartner this morning landed from his 17-mile dive back to Earth from the edge of space, in a plummet that reached a speed of 600 mph in 20 seconds.

The Records Baumgartner had planned to break included those for the first person to break the sound barrier outside of an aircraft, the record for freefall from the highest altitude, and that for the longest freefall time, expected to be five minutes and 35 seconds, and that for the highest-manned balloon flight.

Serious respect for this guy!

[AZRedhawk44]

This was a "test jump" from 96,000 feet.

http://www.redbullstratos.com/

Top speed was 536mph for this jump.

The real jump will be from around 120,000, they say.

I wonder about the heat of air friction on the suit.

[AJ Dual]

This was a "test jump" from 96,000 feet.

http://www.redbullstratos.com/

Top speed was 536mph for this jump.

The real jump will be from around 120,000, they say.

I wonder about the heat of air friction on the suit.

Air's so thin it's not a problem. By the time it is thick enough, he'll stabilize at a slower terminal velocity.

The thin air is actually the biggest problem with ultra-high altitude jumps like that. The thin air gives the diver nothing to push against with his arms, legs, or hands to steer his body, so it's possible to go into a really high speed flat spin that windmills out your arms and legs so hard you can't pull the chute release, or even so hard it kills him from red-out/black out etc. (And if you do pull your arms and legs in, you just spin faster, conservation of angular momentum like a figure skater...)

IIRC, this guy's suit has a special chute release in his gloves so he can activate the chute even if his arms and legs are experiencing 100G's from a spin, and couldn't bring them to his chest straps etc.

[AZRedhawk44]

I also wonder about ascent speed.

A balloon with buoyancy to get to 100k feet is gonna climb pretty dang fast, down here in the land of the 0-20k where we all live.

Adjustable buoyancy control?  Controlled robotic descent of the balloon for recovery?

Or is it just a "hang on tight and don't black out!" kind of a ride?

[Tallpine]

I also wonder about ascent speed.

A balloon with buoyancy to get to 100k feet is gonna climb pretty dang fast, down here in the land of the 0-20k where we all live.

Adjustable buoyancy control?  Controlled robotic descent of the balloon for recovery?

Or is it just a "hang on tight and don't black out!" kind of a ride?

Probably a balloon designed for considerable expansion as the pressure differential increases 

[GigaBuist]

I wonder about the heat of air friction on the suit.

Friction won't be any higher than in a regular dive.  Heat build up from terminal velocity is going to be the same at 120k as it is at 5k.  Negligible.  I never felt my belly get warm when jumping.

The problem actual space craft has it that low earth orbit speeds are something like 17,500mph.  They reverse down to 10,000 mph before hitting the atmosphere which is where you get the ZOMG HEAT problems. 

IIRC, this guy's suit has a special chute release in his gloves so he can activate the chute even if his arms and legs are experiencing 100G's from a spin, and couldn't bring them to his chest straps etc.

I'm not sure where that comes from, but I haven't been reading up much on this endeavor lately.

Even basic jump units contain an AAD (Automatic Activation Device) that'll flip your reserve out if you pass below altitude X at velocity Y.  They're mandatory.

[AJ Dual]

You're partly right. It's a G-meter that will automatically deploy a stabilizing drogue chute if it reads high G forces or more in his arm for longer than six seconds.

But it is mounted on his wrist for the "windmill" reason I listed above. I had incorrectly remembered it as his manual chute release.

And yeah, I assume there's other automatic main chute releases based on altimeters, air pressure, or GPS, both working in concert or whatever.