Was watching BBC news tonight and they had a story about a guy who is preparing to set a new record for HEIGHT of a parachute jump. He will be sent to the edge of the earth's atmosphere by a capsule pulled by a balloon and when he gets to 23 MILES UP, he will jump out. At some point, the story said, he will reach the speed of sound on his return trip.
BTW, previous record was ONLY (I'm being sarcastic) 21 miles.
I'm betting he burns up on re-entry. 
Its been done, back in the 50s. See project Manhigh.
Manhigh didn't break the sound barrier though. This new attempt will. That's insane. 
Javelin wrote: Manhigh didn't break the sound barrier though. This new attempt will. That's insane.
Reports I've seen says he did.
IMHO it's insane regardless of the sound barrier. Cool but nuts. :)
Didn't know the body could withstand such speeds with the protection of a vehicle.
Science question, wouldn't he stop accelerating at terminal velocity? Isn't that much slower than the speed of sound?
Gearheadotaku wrote: Didn't know the body could withstand such speeds with the protection of a vehicle. Science question, wouldn't he stop accelerating at terminal velocity? Isn't that much slower than the speed of sound?
I think I remember hearing in physics class that depending on body orientation, terminal velocity for a human is anywhere from about 110-250 MPH. Speed of sound is... What, 770 MPH?
Of course, the terminal velocity of a human probably was not calculated 23 miles high, so there could be huge atmospheric differences coming into play here.
Gearheadotaku wrote: Didn't know the body could withstand such speeds with the protection of a vehicle. Science question, wouldn't he stop accelerating at terminal velocity? Isn't that much slower than the speed of sound?
At higher altitudes the air is much thinner, to the effect of less wind resistance, highly increased terminal velocity.
see also, why they need oxygen tanks on Mt Everest
Project Excelsior was the high altitude parachute exercise. Jumped from almost 103,000 ft... The jumper had a failure in his glove too--and temporarily lost the use of his hand during the ascent and jump.
Wouldn't you basically need a space suit at that altitude? Go much higher than that and you would need to worry about falling up.
This is appropriate. The jump referenced above is covered.
10 Badassest Jumps in History of Ever: http://www.youtube.com/watch?feature=player_embedded&v=qqhlfz9GQPE
Approves.
I wonder if this is the same halfwit that had the Canadian media chasing its tail all last year? He never did jump...
ST_ZX2 wrote: Project Excelsior was the high altitude parachute exercise. Jumped from almost 103,000 ft... The jumper had a failure in his glove too--and temporarily lost the use of his hand during the ascent and jump.
That wasn't the good one.
The good one is where he went into a flat spin when his drogue chute didn't develop properly (IIRC) and his body saw something like 20+g at his extremities
HappyAndy wrote: Wouldn't you basically need a space suit at that altitude? Go much higher than that and you would need to worry about falling up.
Well.... gravity will always be pulling you towards the planet no matter how far away you are. Orbit (zero gravity) is just when you're going so fast that, as quick as you're falling, the planet's surface is receding. (Picture a bullet's drop... now picture the bullet going fast enough that the drop matched the planet's curvature)
Or, another way, it's when your centrifugal force cancels out gravity. Vomit Comet on a grand scale.
And yes, you do need a space suit. The old tests were to see how feasible it'd be to suit up a pilot so he could punch out at extreme altitude.
mtn wrote:Gearheadotaku wrote: Didn't know the body could withstand such speeds with the protection of a vehicle. Science question, wouldn't he stop accelerating at terminal velocity? Isn't that much slower than the speed of sound?I think I remember hearing in physics class that depending on body orientation, terminal velocity for a human is anywhere from about 110-250 MPH. Speed of sound is... What, 770 MPH? Of course, the terminal velocity of a human probably was not calculated 23 miles high, so there could be huge atmospheric differences coming into play here.
That's what I remember also.
This is from Wiki, and is how I remember it being reported on various TV shows:
On August 16, 1960, he made the final jump from the Excelsior III at 102,800 feet (31,300 m).[2] Towing a small drogue parachute for initial stabilization, he fell for four minutes and 36 seconds, reaching a maximum speed of 614 miles per hour (988 km/h)[3][4] before opening his parachute at 18,000 feet (5,500 m). Pressurization for his right glove malfunctioned during the ascent, and his right hand swelled up to twice its normal size.[5][6] He set historical numbers for highest balloon ascent, highest parachute jump, longest drogue-fall (four minutes), and fastest speed by a human being through the atmosphere.[7] These are still current USAF records, but were not submitted for aerospace world records to the Fédération Aéronautique Internationale (FAI).
A different Wiki page has that speed at 90% speed of sound at that altitude.
Couple of things that make it happen- air is so thin, sea level kind of terminal velocisty isn't terribly close, which is how this jump, and the jump Javelin posts about should get to that high of speed; the speed of sound changes with temperature, so the lower it is, the slower the speed- air temp at that altitude is nice and low (relative to us), so the speed of sound goes down- a 100F decrease in temp lowers the speed of sound a little over 12%.
What's crazy are the failures- the early test put him into the flat spin as reported before. Nuts. Made the back up systems automatically deploy the chute. The 103k jump- his glove failed, and he lost use of his hand for most of the jump.
Even with that, he fell for just 4:36 WITH a staiblizer chute. How fast could you go with out that???
The Mach number changes with altitude.
Appleseed wrote: Its been done, back in the 50s. See project Manhigh.
world record jump from the edge of the planets atmosphere...with equipment built from a lunch box and masking tape...
seems legit
RossD wrote: The Mach number changes with altitude.
Correct. And with humidity, and temperature.
A pressure suit (space suit) is needed above about 60,000 ft. Your blood will boil, due to lack of atmospheric pressure, at that altitude.
pilotbraden wrote: A pressure suit (space suit) is needed above about 60,000 ft. Your blood will boil, due to lack of atmospheric pressure, at that altitude.
I thought this has been disproved? Technically, you can actually be buck naked in space and survive (unless the sun beams directly on you, then you are probably screwed).
Ya, it'd suck, but it is perfectly possible.
alfadriver wrote: IMHO it's insane regardless of the sound barrier. Cool but nuts. :)
Real big nuts....
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