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Stratospheric Skydiving

Hemos posted more than 13 years ago | from the sonic-boom-from-the-body dept.

Space 117

nikhil_g writes " National Geographic has the tidbits about an attempt that sounds as bizzare as they come. It seems to be on horizon with a US Team also planning sooner than the Australian attempt in 2002. " Feed Mag has more complete coverage as well. It's certainly way to spend your time.

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All the way in from LEO (1)

Anonymous Coward | more than 13 years ago | (#374746)

About 15 years ago I was an 'industrial consultant' to a grad student doing a thesis on a personnal glider for reentry from Low Earth Orbit.

Her three stage concept started with a small, discardable retro rocket for initial slowdown. Then about 8 hours of hypersonic, parabolic dips into and back out of the upper atmosphere to bleed speed so as to match the earth's rotation at an altitude of about 50 miles. This was followed by a comparatively low speed glide to the earth's surface.

I have not heard of her (or anyone else) actually building her 'personal reentry glider', but it would be neat.

Re:Advertisment (1)

Anonymous Coward | more than 13 years ago | (#374747)

Advert for Skydiving club night out at Edinburgh Uni: "Pull or Die!"

Re:Already Been Done (Project Excelsior) (1)

Anonymous Coward | more than 13 years ago | (#374748)

There has been at least one more person other than Captain Kittinger who broke the speed of sound without a vehicle, in this case not intentionally. He was also a US Air Force pilot. During a night training flight over the Atlantic his F-15 Eagle had a malfunction causing him to loose all instrumentation. The plane went into a dive, when he bailed out he was moving faster than the speed of sound. The ejection ripped his gear off of him and left him floating in the drink with half the bones in his body broken. He got pulled out by a Rescue Team and is flying again.

Re:not really (1)

peter hoffman (2017) | more than 13 years ago | (#374749)

Btw: the page at the Wright Patterson Airforce Museum [] says 714 mph. I am suspecting that the discrepencies people are finding wrt supersonic or not and other details are artifacts of Cold War paranoia.

OpenSourcerers []

Re:Human Crater Maker (1)

_14k4 (5085) | more than 13 years ago | (#374751)

I suppose I should do the rest of my AFF jumps and get my own gear before I try this? :) A student chute might not survive. Plus, it'd take a lot of Estes class B rockets to push me up that high anyway. So, I'll just give up now and stick to the King Air.

Just like a normal skydiver... (1)

Mumble01 (5809) | more than 13 years ago | (#374752)

If he steers with his body like a normal skydiver would, won't his arms be ripped off? Suit or no suit, he's going to be traveling around 1000 miles per hour...

Re:Just like a normal skydiver... (1)

Mumble01 (5809) | more than 13 years ago | (#374753)

No honest question goes unpunished...

Please allow me to bow before your superior intellect, asshole. Do you remember what it was like before you knew everything?

Re:Starship Troopers, here we come! (1)

SEWilco (27983) | more than 13 years ago | (#374755)

With GPS technology, everyone can try to land on the first guy's foot. The problem becomes one of keeping them from flying into each other.

Re:Nothing new (1)

JatTDB (29747) | more than 13 years ago | (#374756)

They did it, but not as high (and therefore with a lower maximum speed before the air resistance becomes a major factor).

Re:Starship Troopers, here we come! (1)

p3d0 (42270) | more than 13 years ago | (#374757)

No, diving from a baloon is totally different from diving from orbit. In orbit, you're travelling at 18,000mph, so you burn up on re-entry unless you have some serious heat shielding. A baloon is essentially stationary with respect to the ground, so you're starting from a standstill.
Patrick Doyle

Re:ISS Emergency Exit! (1)

ASCIIMan (47627) | more than 13 years ago | (#374759)

Except the orbital speed they jump off at means there would be large air resistance going through the atmosphere.

Quick way to make crispy Astronauts.

Re:One word. (1)

ASCIIMan (47627) | more than 13 years ago | (#374760)

Except he won't be flaming.

And I doubt there will be an inflatable dinosaur.

The meteorite part sounds quite accurate, though.

One word. (1)

ASCIIMan (47627) | more than 13 years ago | (#374761)


Re:Already Been Done (Project Excelsior) (1)

ASCIIMan (47627) | more than 13 years ago | (#374762)

"This guy had some serious intestinal fortitude."

See that big orange box strapped to his rear?

That's a porta-potty.

Full radio communication? (1)

T3kno (51315) | more than 13 years ago | (#374763)

I can hear it now. "Base to space dive, come in space dive - over"

"Space dive here - over"

"Space dive confirm, was that a fart or a sonic pop? - over"

Stability in light air (1)

xerx (63759) | more than 13 years ago | (#374764)

The biggest danger in these jumps is that it is very difficult to maintain stability at high speeds in thin air. Why? If you become unstable at that speed the forces generated could easily rip all your extremities off and really ruin your day. Drogue chutes have been deployed to help in stability, but previous attempts at lower altitudes have shown that these chutes become less effective the more extreme the altitude.

Re:What about friction? (1)

fnj (64210) | more than 13 years ago | (#374765)

The space shuttle is going 18,000 mph on re-entry. He won't be going that fast. 700-900 mph. Big difference.

What about friction? (1)

Morel (67425) | more than 13 years ago | (#374766)

This guy says: "...As I get into the thicker atmosphere it will gradually slow me down to normal speed."
As I see it, the thicker atmosphere will slow him down by friction, generating enormous amount of heat and maybe even a nasty high-frequency vibration. How is that survivable? I mean, they can't plaster the suit with ceramic tiles, right?


Re:Already Been Done (Project Excelsior) (1)

NTSwerver (92128) | more than 13 years ago | (#374767)

It wasn't as high as this attempt will be though.

In this attempt, the parachutist will exceed 800mph in the initial free-fall !


Re:Stratosphere? (1)

Ironworks (94258) | more than 13 years ago | (#374768)

The article on Feed Mag boasts that this he will be "the first person to travel faster than the speed of sound". Not so! Was done back in the sixties. Super Sonic speeds were reached by a man in a space suit that jumped from a ballon. The guy is still alive today. I saw him on an interview on the discovery channel.

Re:Breaking sound barrier? (1)

Sc00ter (99550) | more than 13 years ago | (#374769)

Ahh, gotcha. Never thought of that. Thanks for clearing that up.


Breaking sound barrier? (1)

Sc00ter (99550) | more than 13 years ago | (#374770)

Terminal velocity of a human is like 120mph I read. How could you go faster??

Re:Stratosphere? (1)

ozbon (99708) | more than 13 years ago | (#374771)

IANAS (I am not a skydiver ;) ) but hell, it sounds like fun to me.

Respect to the guy, and his lunatic plans!

What about that girl? (1)

dciman (106457) | more than 13 years ago | (#374773)

Didn't Slash cover a story about a girl planning on doing this? If I remember right... she was planning on jumping from 165,000 feet or so. What cooountry was she going to be jumping for?

Re:Stratosphere? (1)

Listen Up (107011) | more than 13 years ago | (#374774)

I'm sorry...I never claimed to be an expert on the subject of Stratosphere skydiving. Thank you for clearing up the facts of my obviously somewhat faulty memory. After more research, the Air Force website was very helpful in refreshing what I thought were factual memories. But, the question still needs to be begged...Why do this at all ?. Oh well, whatever floats your boat I guess :-)

Clueless journalist or what? (1)

jccq (113245) | more than 13 years ago | (#374775)

this made me laugh for some time : "Other effects, like the physiological outcome of accelerating from zero to possibly 900 miles an hour in less than a minute and exceeding the sound threshold "
ahahah :)
there will be NO accelleration on his body at all during the free fall then he will SLOWLY decelerate once entering in the atmosphere..
If they said something like this i dubt they have enough clues of physics to make him actually survive the actual threats of the jump. :) good luck.

Re:One word. (1)

Paul Bristow (118584) | more than 13 years ago | (#374776)

Maybe this is what inspired the scene in Armageddon where the flaming chunk of meteorite took out the inflatable dinosaur?

I want one! (1)

wmol (124342) | more than 13 years ago | (#374778)

My questions are: 1. Where do i sign up? 2. How much does it cost? 3. Do I have to jump tandem the first time? I think i have found a replacement for my Cliff-diving addiction!

Two words: "stagnation temperature".. (1)

kd5biv (129563) | more than 13 years ago | (#374779)

When this guy does his dive, I really hope whatever hits the air first is well insulated. The air density may be low, and the temperature won't be terribly high at M1.4, but any part of his body generating a shock wave is going to heat up to some extent. I'm sure that's been taken care of, but it could be rather uncomfortable for, say, fingertips ..

Hmm... (1)

Ibby (130127) | more than 13 years ago | (#374780)

Perhaps stories should be posted a little later in the day, when all the trolls have gone to sleep...

Re:Planetfall! Ivasion form space! (1)

ajna (151852) | more than 13 years ago | (#374783)

Would they have to use a combination of 'rocks' and spaceborne infantry raids? Or, would the only reasonable deterent be total destruction? I think there's a sci-fi story in this here.

Read Red Star: A Utopia by A. Bogdanov (1908), in particular the character Sterni's reasoning over the feasibility of colonizing Earth (from Mars - Sterni is a Martian). If you're too lazy to read it, the summary: all humans would have to be exterminated, or else they would fight the Martians to the bitter end because of their nationalism (not quite the appropriate word, more like their shared bond as humans).

Free fall time (1)

TeknoHog (164938) | more than 13 years ago | (#374785)

Seven minutes of free fall! Don't they say it's better than sex? And now it even lasts longer...


Re:Explain this (1)

TeknoHog (164938) | more than 13 years ago | (#374786)

IANASS (supersonic specialist) but as a physics student I've gathered some info on this. There's not really any 'sound barrier' to break. The myth has probably smething to do with the sonic boom which you feel/hear if a supersonic aircraft flies by, but that happens even when it's flying at a constant speed (greater than speed of sound).

For airplanes, something may be happening at the transition speed, since wings operate differently for sub/supersonic speeds. But this should have no effect for the skydiver. He may have other problems with the heat from the air drag, though. Also the pressure differences created in the air around him can have interesting effects - high on the head, low on the sides. But these will occur even in subsonic speeds.

Now if there's a supersonic specialist around, please correct me if I'm wrong :-)


Re:What about the air density? (1)

TeknoHog (164938) | more than 13 years ago | (#374787)

IAAP. Speed of sound == sqrt(pressure / density), for most gases the pressure is proportional to density so the speed of sound is (roughly) constant.


Re:Atmospheric Friction (1)

OwnedByTheMan (169684) | more than 13 years ago | (#374788)

I have not seen the details of the jump but he will likely be using a drogue chute as did Joe Kittinger in the 50's [] .

A drogue chute is a small parachute that is deployed to slow the terminal velocity of a skydiver to a manageable level. If you have ever watched a tandem jump (skydiving instructor attached directly to the student at the shoulders and hips from the rear) you have seen a drogue chute. They are used because tandems present equal surface area but roughy double the mass (sometimes more) of a normail, sungle skydiver and tend to accelerate to un-manageable speeds. (The faster you travel, the more violent and "touchy" the body movements become having greater and greater effect on relative position in the air.)

In the case of Kittinger's space jump, his drogue was substantially larger than the main parachutes we use today but the density of the air is so thin that it needs to be very large to have any effect.

Re:ISS Emergency Exit! (1)

Viadd (173388) | more than 13 years ago | (#374789)

Look at MOOSE--Man Out Of Space Easiest. []

Under the rule of thumb mentioned, you wouldn't need 400 feet per second since air drag gets you once you're down to, say 50 nm. Call it 320 feet per second, or 10 g-seconds. If your rocket pack has a specific impulse of 250 seconds, then 15 pounds of rocket can de-orbit 375 pounds of ballsy/desparate astronaut, life support, heat shield, chute, etc.

One proposal presented to NASA included a line something like 'An emergency space rescue system does not have to be any safer than bailing out of a malfunctioning fighter plane.' Needless to say, NASA objected to such a statement (how can you even think of doing something that's not 100% safe?). An Air Force station would presumably have more realistic safety requirements than NASA.

Re:Also... (1)

Gibbys Box of Trix (176568) | more than 13 years ago | (#374790)

You forgot the Good Guy swooping down on the Bad Guy because the Bad Guy took the last parachute, a la Point Break
01 13 19

Re:not really (1)

Gibbys Box of Trix (176568) | more than 13 years ago | (#374791)

Never mind the clouds, I'd expect that the curvature of the Earth would be pretty pronounced from up there (correct me if I'm wrong). THAT would be the clincher for me...
01 13 19

Human Crater Maker (1)

Alien54 (180860) | more than 13 years ago | (#374792)

Slashdot has covered this story in varying detail over the past few months.

Still it is an interesting story with a wild history. One thing is for sure, is that you do not want anything anything anything to go wrong. You won't burn up, although that is the first image people get.

The big problem is not tumbling like a rag doll with no way to control yourself for five or more minutes, Then being sufficiently disoriented that you become a human crater maker.

My only comment is... (1)

grammar nazi (197303) | more than 13 years ago | (#374794)

All that I have to say is: F=ma

...well, that and 9.8 kg*m/s^2

Re:Explain this (1)

SunCrusher (207578) | more than 13 years ago | (#374795)

They way I understand this (and I'm certainly no expert) is that at the altitude where he's going to be supersonic the air is so thin that, although he's creating a "sonic boom" it won't be causing near as much force as it would with thicker air. Basically it's the same effect, but lower forces are involved because of the lower pressure. (Of course I've been wrong before....)

Re:This guy was on the radio this morning... (1)

3G (220614) | more than 13 years ago | (#374797)

Not to be pedantic, but the Jet Stream generally flows under the US on the west coast [] , so his best bet would be to traverse over Mexico.

More stratosphere facts! (1)

AFCArchvile (221494) | more than 13 years ago | (#374798)

Did you know that the space shuttle Columbia, on its first flight, entered the atmosphere at Mach 27? When it hit the lower reaches of the atmosphere, observers heard a triple sonic boom.

Re:Joe Kittinger been there, did that (1)

Scratch-O-Matic (245992) | more than 13 years ago | (#374799)

A little different, I think. Kittenger had a drogue chute for stability (which almost strangled him to death, by the way,) and this guy doesn't seem to be doing that.

I wonder if he's going to be in a "diving torpedo" type position, or the standard sky-diving "frog." He might experience some interesting disclocation or breakage in the latter.


Re:Just like a normal skydiver... (1)

CU-Ballistic (248908) | more than 13 years ago | (#374801)

Thin air, dipshit.

not really (1)

Kraft (253059) | more than 13 years ago | (#374802)

"Though my stabilization chute opens at 96,000 feet, I accelerate for 6,000 feet more before hitting a peak of 614 miles an hour, nine-tenths the speed of sound at my altitude."
(Kittinger (the diver) in Life magazine [] , August 29, 1960).


Kahoona's! (1)

Lede Singer (253091) | more than 13 years ago | (#374803)

Regardless of who does it, they've certainly got something that I don't; or I've got something they don't. Either way, they can have their fun...I guess.

Now that I think about it though, we could start doing lots of cool things from that height; imagine how far a man could hanglide from up there?? "My life should be accompanied my a musical score"

Re:Clueless journalist or what? (1)

Muad'Dave (255648) | more than 13 years ago | (#374804)

A slight correction - there will still be 9.7 - 9.8 m/s acceleration on him - otherwise he wouldn't be falling! What he'll lack is the force caused by air resistance. 'Normal' skydivers feel the force of the air on them as they fall, which counteracts some of the force generated by the fall. (Hence their 'terminal velocity').

He'll most likely not feel a heckuva lot of resistance until he gets deeper into the atmosphere.

Excelsior skydive (1)

adx200 (263718) | more than 13 years ago | (#374805)

Yeah, I remember the picture from Nat'l Geographic's coverage a while back...the platform that he jumped from had (paraphrase) The Biggest Step In The World painted on it. My roommate and I were paratroopers in the 82nd Abn Infantry at the time, and we were joking about if this guy showed up at one of the local Army bars. "Yeah, so the other day, we jumped from 600 feet" His reply: "I jumped from 50 miles up yesterday." All jaws drop to floor.

Human meteor (1)

BLAMM! (301082) | more than 13 years ago | (#374806)

Imagine moving that fast and twitching your arm or leg. You'd go tumbling completely out of control and be damn lucky not to have a limb torn off. And this guy thinks he'll land 50 feet from his launch site? Crazy is only half this guys problem.

Loookie Here!! Et tu Francis! (1)

nikhil_g (303950) | more than 13 years ago | (#374807)

As detailed here, [] a comprehensive research seems to have been done, strangely enough provoked by the Challenger Tragedy. [] The date of the attempt has been postponed ad infinitum. Though the way scientific possibillities and challenges are written down, this does not seem so foolhardy.

Insurance salesmen = Crash test dummies? (1)

Caid Raspa (304283) | more than 13 years ago | (#374808)

They are using insurance salesmen as crash test dummies when testing astronaut equipment?

Nice idea. Perhaps GM and Ford could use this one. I hope it is not patented.

National Geographic says the landing point will be within 30 miles from the takeoff point, as Feed says the official guess is 50 feet. Maybe they used NASA unit conversion convetion? I hope other numbers in the articles are more accurate.

Re:Starship Troopers, here we come! (1)

Savage-Rabbit (308260) | more than 13 years ago | (#374810)

Would'nt spread on the dropzone be a problem? I can just imagine a battalion being spread over half a continent running into problems trying to regroup.

Pilotless dropships that could take a cannister with 10-20 grunts + 1 officer and some gear or a piece of heavy duty hardware like a tank would be much easier to insert with precision.

Atmospheric Friction (1)

mr bushley (324084) | more than 13 years ago | (#374812)

I wish they better described the suit he's going to be wearing. If he's really diving from that high up, he's going to be experiencing some severe atmospheric friction on the way down. It would be highly unlpleasnt if he started burning before he set his record.

It sounds exhilarating to break the sound barrier without a vehicle of some type.

News at 11 (2)

Anonymous Coward | more than 13 years ago | (#374813)

"Stratospheric Skydiver dies in a collision with a falling Mir junk piece."

Skydiver team: "We should have checked the space weather"
Russian officials: "We thought the stratosphere were belong to us at that time !!"

Re:Already Been Done (Project Excelsior) (2)

Zachary Kessin (1372) | more than 13 years ago | (#374814)

Yes they are trying to break that record. At least one of the people trying is a former member of the Golden Knights the US Army's parachute display team. So if She thinks that she can do it I'm tempeted to belive it.

I also read on the AOPA site ( that someone is trying to get a glider to 100,000 ft.

I'll stick to playing at 5-10,000 ft thanks.

Re:not really (2)

CoreDump (1715) | more than 13 years ago | (#374815)


On the face of it, I can't argue with your math there. It certainly does seem plausible. It's still wicked insane to think that this guy did what he did willingly over 40 years ago!

I don't know if I'd have had it in me to step off the edge of that platform looking down and seeing the clouds that far below. :)

------------------------------------------------ ------------

Re:not really (2)

CoreDump (1715) | more than 13 years ago | (#374816)

According the official Air Force site:

He experienced temperatures as low as minus 94 degrees Fahrenheit and a maximum speed of 714 miles per hour, exceeding the speed of sound.

------------------------------------------------ ------------

Re:Joe Kittinger been there, did that (2)

peter hoffman (2017) | more than 13 years ago | (#374817)

According to what I have read elsewhere, and as cited at PBS [] , Kittenger did go supersonic during his jump.

OpenSourcerers []

Re:Already Been Done (Project Excelsior) (2)

drix (4602) | more than 13 years ago | (#374818)

I saw this guy interviewed once. Trust me, he's more fucking kickass than you can possibly imagine. Think Napoleon Bonaparte meets Ghengis Khan meets Chuck Yeager. He'd beat that thing's ass. Fuckin' a.


StratoQuest (American effort) (2)

DHartung (13689) | more than 13 years ago | (#374819)

There is an American effort underway, briefly mentioned in both articles, that seems more likely to succeed. Cheryl Stearns, a world-record parachutist, will descend from 130,000 feet (or possibly higher) in Project Stratoquest [] . They've been working for about two years now, and have performed several practice jumps to test equipment configurations. In fact, the Stratoquest attempt has been covered on Slashdot twice [] before [] .

Millner will have an opportunity, of course, to surpass her record by going second (assuming either survives). He will also definitely be the new Australian record holder. What his presence in this competition shows is a new interest in stretching the limits of our capabilities in this area, and that's good.

Is either Millner or Stearns disrespectful of the 1960 record of Col. Kittinger? No. Stearns shows an excellent series of photos [] of the Kittinger jump as part of her team's website. The Millner story has been circulating but only through secondary journalistic sources, so we have no way of knowing whether he has said anything about Kittinger. No matter what, both efforts seek to slam Kittinger's record into history by surpassing it. By five or six miles, maybe as many as ten miles.

By any measure, that isn't something that's "already been done", and the posts to that effect were all unnecessarily snarky. (I notice there were snarky posts in the earlier threads as well.) Millner and Stearns know the history of their sport just as much as, well, Linus Torvalds knows the history of operating systems. They're building on what was done before.

Re:not really (2)

Moofie (22272) | more than 13 years ago | (#374822)

I _am_ a rocket scientist (in training) and you are correct. : )

Speed of sound goes down as altitude goes up, due to thinner atmosphere. I think there is an altitude at which speed of sound goes back up, due to the coldness of the air, but I can't find any data close to hand that support my (possibly faulty) recollection.

Read here for more info.

Re:Joe Kittinger been there, did that (2)

Moofie (22272) | more than 13 years ago | (#374823)

As long as he doesn't change body position, he won't break limbs. Think about it...if he lays down in the frog position, there's going to be a pressure force distributed across his body equal to his weight when he reaches terminal velocity, just like "low-altitude" skydivers. In other words, terminal velocity is reached when the pressure force exerted on your body by the air you're running into equals your weight. He won't have any more or less stress on his limbs than a regular skydiver...he'll just be traveling faster through thinner air. As he comes down into thicker air, he'll slow down to a normal skydiver speed, and since the pressure of the atmosphere increases gradually, the deceleration will be constant and non-traumatic.

I bet that even if he started in a torpedo and switched to a frog position, he'd have no more stress on his limbs than a regular skydiver performing the same maneuver....

And am I misremembering that there was a woman who was also making an attempt on Captain Kittenger's record?

SR-71 pilot held the record a while (2)

Sxooter (29722) | more than 13 years ago | (#374824)

During the 60s, and SR71 pilot flying at over 100,000 feet and over mach 3 had a catastrophic SAS failure SAS is the stability augmentation system that makes big planes easy to fly basically) when it's sensors reported less fuel in the rear tanks than there actually was. The pilot initiated a turn and the plane simply disintegrated around him.

Luckily for him he was wearing the "space suit" built for use in that plane, and he was basically uninjured. I read about that in some literature about the Lockheed Skunkworks once, I wonder if they have that story online somewhere now.

Re:Already Been Done (Project Excelsior) (2)

thetzar (30126) | more than 13 years ago | (#374825)

Note that the webpage doesn't state that the jumper will be the 'first' man to break the sound barrier unaided, but the 'fastest'. I assume that means they are aware of this previous attempt, and simply plan to surpass it.

Re:ISS Emergency Exit! (2)

Kartoffel (30238) | more than 13 years ago | (#374826)

It would take a really big braking motor to bring decelrate an astronaut enough so that he/she would fall straight down.

When calculating the delta-V you need to get down from low earth orbit, the general rule is 2 feet per second per nautical mile altitude (sorry metric folks, NASA still uses Real Units ;)

The International Space Station is currently in a 371x382 km orbit, (or about 200 nmi). That means that a vehicle deorbiting from that altitude needs to slow down by 400 feet per second.

Suppose the astronaut plus a small heat shield, space suit, and parachute weighs 250kg. Total impulse required would be 250kg multiplied by 400 feet(122 meters), or 30kilonewton-seconds. That's equivalent to 1500 "D" size model rocket engines just to reach entry interface.

compared to bailout from orbit (2)

Kartoffel (30238) | more than 13 years ago | (#374827)

Pretty impressive for a jump from a balloon! In the early days of the space program there were lots of schemes to allow an astronaut to bailout from orbit. The problem there, however, is that you've got to decelerate through the atmosphere. The Encyclopedia Astronautica has some examples of orbital bailout systems [] .

Some [] of the concepts of them were nothing more than a small solid rocket to give the delta-V to come home and a small aeroshell to shield the astronaut until he got low and slow enough to use a regular parachute.

For the physics-challenged: jumping from a stationary balloon means you fall straight down. Going 1000 miles per hour through the stratosphere is not fast enough to generate dangerous heat. Coming down from low earth orbit, however, (at 17,000 miles per hour) is an entirely different thing.

Reason for multiple booms (2)

Kartoffel (30238) | more than 13 years ago | (#374828)

In some situations an observer can hear two sonic booms. One from the shock at the nose and one from the tail. Any protrusion in a supersonic flow will tend to generate its own shock. The 3 booms observed in that case probably came from the nose, the tail, and the OMS pods.

When a vehicle is ascending or descending rapidly the individual shocks at the nose and tail tend to be farther apart, as observed from a listener on the ground. The Shuttle is slighly more aerodynamic than a brick, and it flys as such). It's a good example of the kind of situation you need to hear multiple booms.

The Shuttle also breaks the sound barrier on the way UP, but since it's climbing rapidly and heading out over the ocean, observers in Florida don't hear anything besides the roar of the rockets.

hmmmm. (2)

supabeast! (84658) | more than 13 years ago | (#374830)

From the National Geographic article -

"The Australian will be dressed like an astronaut to protect his body from extreme pressures during his jump."

Seems to me that they should be far more worried about the extreme LACK of pressure.

Of course, one would think that the real danger would be heat from the fall.

Seriously, tho, good luck to him. Looks damned fun, I wish I could try it.

Re:What about friction? (2)

ers81239 (94163) | more than 13 years ago | (#374831)

Actually he'll be going way slower than spacecraft which are in orbit. See they are not only falling, but mostly going really fast AROUND the earth as well. This from the FAQ:
How fast does a Space Shuttle travel? What is its altitude? How much fuel does it use?

Like any other object in low Earth orbit, a Shuttle must reach speeds of about 17,500 mph (28,000 kilometers per hour) to remain in orbit.
So 800 mph...doesn't quite compare.

This guy was on the radio this morning... (2)

chemguru (104422) | more than 13 years ago | (#374832)

The guy planning to do the jump/dive was on ( in Atlanta ) earlier this morning. Sounds pretty cool. I'd be interested to know how far he could traverse ( i.e. he jumped out directly over, say California, rode the Jet Stream.. where would he end up? )


First or Fastest? (2)

localman (111171) | more than 13 years ago | (#374833)

From the article:

he will ... become the fastest man to break the sound barrier unaided

At first I assumed this was a typo, but then I remembered that the speed of sound isn't constant, and depends on the air pressure. Although likely unintentional, is there any truth to the statement? That he will be the "fastest" man to break the sound barrier? I forget which way it goes (I would think slower at higher altitudes/lower pressure...)

Re:Already Been Done (Project Excelsior) (2)

S.O.B. (136083) | more than 13 years ago | (#374835)

If the webpage you are referring to is the National Geographic then you are correct. However, the Feed Mag article reads, "If he is successful, he will be the first human to break the sound barrier sans vehicle.", which is incorrect.

Re:Stratosphere? (2)

Prof_Dagoski (142697) | more than 13 years ago | (#374836)

According to the History Channel documentary on Project Man High, the test pilot who jumped had problems with his suit. Actually, I think he had hurt his hand and he couldn't put his glove on over his now swollen hand. So, he just went up with a glove. He also had some serious problems with going into a spin on the way down. But, eventually he stopped spinning and made it down with a little bit of frost bite and a few bruises.

Re:Planetfall! Ivasion form space! (2)

Prof_Dagoski (142697) | more than 13 years ago | (#374837)

Given the cost in fuel and engery needed to haul an invasion force, I wonder if planetary invasion would ever be feasible. And, if not, what options would military leaders have for pacifying a planet? Would it be enough to simply assume control of local space and threaten to drop rocks on them if they got out of line? Would they have to use a combination of 'rocks' and spaceborne infantry raids? Or, would the only reasonable deterent be total destruction? I think there's a sci-fi story in this here.

Look Up 'Man High' (2)

Prof_Dagoski (142697) | more than 13 years ago | (#374838)

This sort of skydiving has, of course been done before. Back in the early(?) fifties the Air Force had a project called Man High that was tasked with developing escape systems for high altitude aircraft. It started by hauling crash test dummies up in weather balloons and dropping them with various parachute systems to test them. Man High is occasianlly cited as being partially responsible for the whole alien body legend for this reason. The projected culminated with a live test pilot dropping out of one of these weather balloon. He had one wild ride. The History Channel did a good documentary on this programmer which was a forerunner to the US manned space program. If you go to your favorite search engin and search for Man High, you can also find a good web site with info on the project. You'll also find a whole lot gay porn sites in the hitlist, so be careful which links you follow.

What about the air density? (2)

dohnut (189348) | more than 13 years ago | (#374840)

IANA physicist, but isn't the speed of sound proportional to the density of the material through which it travels ( as a rule of thumb )? As in, the less dense a material, the lower the speed of sound becomes.

So, this guy really doesn't have to go that fast to break the speed of sound with the air density he'll be travelling through. I mean, he's not going to be able to maintain faster than sound travel as air pressure approaches 1 atmosphere.

So really, who cares, it's relative. Astronauts doing space walks have probably gone faster in relation to the earth than this guy will. If I'm in space and I strap a rocket to my back, to propel myself faster than the speed of sound at sea level on earth, well, so what?

It's a cool stunt, but if he really wants to impress me, travel at 343 m/s 10 feet off the floor of the Arizona desert. Probably traveling horizontally rather than vertically though..

ISS Emergency Exit! (2)

DavidGSteadman (202145) | more than 13 years ago | (#374841)

Now that the X-Planes projects have been canned, perhaps NASA should ask their astronauts to jump out the hatch if anything goes wrong! Take 1 Suit, 1 braking motor, 1 parachute and 10 rolls of duct tape.....

Re:Already Been Done (Project Excelsior) (2)

adamn (202352) | more than 13 years ago | (#374842)

Note the orange box in the picture -- clearly there to hold his huge balls.

Starship Troopers, here we come! (2)

mfarah (231411) | more than 13 years ago | (#374843)

This kind of diving is the precursor to what Heinlein described at the beginning of _Starship Troopers_: throw the infantry off to a planet from orbit, where they do a hit&run operation, and are picked up a while later by landing ships. Military implications of this are very very interesting.

Death to Vermin.

Good Quote (2)

LordArathres (244483) | more than 13 years ago | (#374844)

I personally like this quote from the article.

If he reaches 130,000 feet, he will certainly hit it. The only question is: how hard?

Ouch, at least they all have faith, eventhough they might scoop his body up through a vacuum cleaner.

Lord Arathres

makes for a good mountain dew commericial (2)

CheechBG (247105) | more than 13 years ago | (#374845)

look on the bright side, in the unlikely event (IMHO) that he were to survive, he could have a lifetime contract with Coke starring in Mountain Dew commercials... Maybe Mel Torme would like to go along?

Re:not really (2)

Kraft (253059) | more than 13 years ago | (#374846)

Yes I did read your original post, and your sources ;)

For what it's worth, somebody has bothered to do the calculations for us here [] , and they seem to set the record straight.

"According to Captain Kittinger's 1960 report in National Geographic, he was in free fall from 102,800 to 96,000 feet and then experienced no noticeable change in acceleration for an additional 6,000 feet despite having deployed his stabilization chute. This gave him an unprecedented 3900 m (12,800 feet) over which to accelerate. At such extreme altitudes the acceleration due to gravity is not the standard 9.81 m/s2, but the slightly lower value of 9.72 m/s2. Using these numbers, it is possible to calculate the maximum theoretical velocity experienced during this record-setting jump. The result is amazingly close to the value recorded in National Geographic.
"Given this, why then do so many sources report that Kittinger exceeded the speed of sound? One possible answer comes from the relatively obvious similarity between Kittinger's self-reported value of 614 mph and the most frequently misreported value of 714 mph (319 m/s). Somebody must have heard 614 but entered 714 accidentally into some officious document (like an encyclopedia). Some other people read the error and then reported it as fact. Many more people read these "facts" and suddenly nearly everyone was remembering the day Captain Kittinger broke the sound barrier. Another factoid is born.
"Captain Kittinger most likely did not exceed the speed of sound on 16 August 1960. To do so would have required an additional 1,300 m (4,200 feet) of free fall. That's a pretty large distance. I think he would have noticed it. This in no way detracts from his truly amazing accomplishment."

IANARS, but this makes sense to me.


Explain this (2)

cavemanf16 (303184) | more than 13 years ago | (#374847)

Nobody has yet sufficiently explained how this guy's skull and helmet are going to survive breaking through the sound barrier. It's my understanding, that once something breaks the sound barrier, the air 'cone' in front of the nose of the aircraft or missile moves slightly aft of the cone of the aircraft. Therefore, to break the sound barrier you need a pointed cone 'nose' on your aircraft to punch through the resulting air wave that is generated while you fly through the air. So is this guy gonna wear a pointy helmet to accomplish this? Will we have a conehead from outer space come visit our planet? :)

Seriously though, I don't understand how his body will survive punching through the 'sound barrier' (read: atmosphere) without a more rigid support system than just his bones and a flame resistant space suit.

Re:Starship Troopers, here we come! (3)

Anonymous Coward | more than 13 years ago | (#374848)

No, it's not. WE already do stuff like this for a long time (remember, the existing record for this was set in the 1950s), it's called "HALO" jumping (High Altitude Low Open). One of the things you can do is fly yourself through the air for that time, instead of just dropping straight down. For some significant ground distance, too.

Reread your Tom Clancy books...

Stratosphere? (3)

Listen Up (107011) | more than 13 years ago | (#374849)

I am a skydiver and 2 1/2 miles high is enough for me. I watched a video on the Discovery Channel or TLC or whatever a while back on some people who jumped from this height for NASA. Exactly what are these people thinking? I have very clear memories of these NASA people actually having their packs, suits, air supply, and gear either burn up completely from air friction to their bodies not being able to handle the pressure/temperature/stress and having serious health problems, even death. Just thinking about falling that far only gives me pictures of the ceramic tiles on the space shuttle. It sounds cool, I have to agree, but the risks or simply ridiculous compared to value of life.

ahhhhhhhhhhhhTHUD! (3)

Raymond Luxury Yacht (112037) | more than 13 years ago | (#374850)

"An experienced skydiver, speedboat racer, scuba diver, and, before that, an insurance salesman,.."

*sigh* now if only we could get more insurance salesmen to do this.

"Millner believes that he will reach a speed of between 700 and 900 miles per hour within one minute of leaping from the balloon."

And within about that same time be carrying a small sewage plant in his undies.

Seas have been done?! (3)

micromoog (206608) | more than 13 years ago | (#374851)

Millner also told Australia's Daily Telegraph he intended to do the jump because, "well, there are no more mountains to climb, the seas have been done, so it's time to go straight up."

Sorry Millner, but the seas ain't been done. We know more about the rings of Saturn than we do about our own ocean floor . . . low pressure is much easier for us to deal with than high pressure.

This is not any significant milestone. This is just a multi-million dollar thrill ride for some egomaniac.

Re:This guy was on the radio this morning... (3)

tamnir (230394) | more than 13 years ago | (#374852)

If the guy jumped over California and rode the Jet Stream, he would probably end up... in California!

The average speed of Jet Stream is 110 to 140 knots (source here [] ). So let's take 140 knots, which is around 4 km/min (to give you a better idea, that's 260 km/h, or 160 mi/h). According to the article [] , the fall should last around 10 minutes. The horizontal drift of the guy would then be:

4 km/min * 10 min = 40 km (27 miles)
Not bad if you consider that the guy jumps from that same distance in height. But anyway, he won't be in the Jet Stream all the way down, so the actual horizontal drift will probably be much lower.

Note: I did not forget the guy's relative horizontal speed (horizontal speed within the wind, as the guy "surfs" on the airflow). That speed is just not significant compared to the speed of the Jet Stream.

.sig under construction...

Also... (3)

Scratch-O-Matic (245992) | more than 13 years ago | (#374853)

Terminal velocity also depends on position. The 120 MPH figure is accurate for the familiar "frog" position. The velocity is about 200 MPH for the "tracking" position, which is the maneuver you see in the movies when the Bad Guy is swooping down on the Good Guy, or when the Good Guy is swooping down to save his Buddy who fell out of the plane without a parachute.


Diving at a speed of between 700 and 900mph... (3)

OpCode42 (253084) | more than 13 years ago | (#374854)

... thats faster than a .com's shares, isn't it?


Advertisment (3)

the_Brainz (308534) | more than 13 years ago | (#374855)

For sale: parachute. Once used, never opened, small stain.

Re:Already Been Done (Project Excelsior) (3)

aileon (311642) | more than 13 years ago | (#374856)

I saw a tv special about the Air Force jump. Its freaking berserk. I mean, it's cool that we can dump people off of those hieghts and they can manage to live through it, but isn't it a bit like testing how tough your toy trucks are by dropping them off higher and higher tables? When they break you make a better truck and try again?

I dunno. My brother is Airborn qualified, as is my dad, my aunt, my uncle, and more of my family, and I think it's kind of retarded to jump out of airplanes anyway, but I suppose sending people around the world to shoot at each other is kind of dumb too, but necessary. The people doing this stuff for the heck of it, or to set a record, now that's just stupid without explanation.

Who covers their insurance? I suppose you don't need health insurance, more like hose-and-bucket-cleanup-and-truckload-of-dirt-for- the-crater insurance


Re:Already Been Done (Project Excelsior) (4)

CoreDump (1715) | more than 13 years ago | (#374857)

Yes, I know, following up my own post, but you just have to see this picture of Air Force Capt. Joeseph Kittinger jumping from the gondola of a baloon at 102,800 feet. The Picture [] pretty much speaks for itself.

This guy had some serious intestinal fortitude.

------------------------------------------------ ------------

Joe Kittinger been there, did that (4)

Kraft (253059) | more than 13 years ago | (#374858)

US Captain Kittinger did this in 1960 (as mentioned in the feedmag article), and although he didn't go faster than sound back then, and wasn't dropped from as high an altitude, it's still a feat keeping in mind. Kittinger himself wrote a detailed article [] in Life magazine about the jump.


Re:Breaking sound barrier? (4)

eXtro (258933) | more than 13 years ago | (#374859)

Terminal velocity depends on the air density. People normally parachute from relatively low altitudes where there is still significant air density. This guys going to be parachuting from 100000 feet, or about 19 miles. Very little air density so his terminal velocity is much higher.

As he descends the air density will pick up and he will slow down.

Already Been Done (Project Excelsior) (5)

CoreDump (1715) | more than 13 years ago | (#374860)

Uhmm, hate to burst their bubble, but this has already been accomplished.

In the 60's while testing Astronaut recovery/escape systems, the U.S. Air Force had someone jump from about that high up. He was testing a 3 stage parachute ( since it can't open all at once due the sheer force of the opening shock ) at the time. It was done somewhere over Arizona. They used a helium balloon to lift him up. There is even a video from a camera fixed in the balloon showing it.

And yes, he did break the speed of sound on the way down. 714 mph! Wheeee. :)

The AF Site []

------------------------------------------------ ------------

Re:Stratosphere? (5)

ASCIIMan (47627) | more than 13 years ago | (#374861)

  • I think it was the Air Force that did this from its high-altitude research balloons. (NASA hadn't even been created yet)
  • I think the guy (IIRC they only did this once) did get a bit of frostbite on some of his fingers/toes and did have a bit of low-pressure whatzit, but didn't die and didn't have any really major health problems.
  • The ceramic tiles on the space shuttle heat up because of air resistance almost entirely from its orbital velocity, not its vertical velocity due to gravity. (Vertical velocity much much smaller than its horizontal/orbital velocity)

I dunno about that (5)

Prof_Dagoski (142697) | more than 13 years ago | (#374862)

Anyone jumping from that kind of altitude is going to be loaded down with a lot of life support equipment. Not much left over in terms of payload for weapons and operational equipment. There are other problems as well. When troops jump HALO(High Altitude Low Opening), what they do is jump out of the plane at every high altitiudes and freefall a very long ways before ever opening their chute. I think they jump from 14000 ft and don't open a chute til 500ft. Someone who knows the actual figures, please correct me. This happens for two reasons: A soldier dangling from a parachute has a very large visual and radar signature. And, the soldiers can jump out over friendly territory and drift during the freefall into the enemy's area. This is ideal for any kind of covert operation, or even just for any action in an enemy's rear.

Jumping from a stratospheric altitude is going to require that several chutes be opened at various altitudes to slow the jumper down, They're going to be very visible a every stage. And, that is going eliminate the primary motivation for parachute operations: stealth and suprise. Not to mention, there's a limit to how much chute you carry relative to its stopping power. Paratroopers carry a _lot_ of equipment, but there's only so much. Add life support to that, plus all the chutes for this kind of jump and you won't have much left over on the ground to fight a battle. Not to mention, the jumper is going to have to get out of their space suit once their on the ground. Presumably, the enemy is going to be looking for the jumper if not shooting at him while he's doing that.

In contrast, the force Heinlein envsioned was basically a tank force. Granted the tanks were anthropmorphic vehicles that operator wore, but the MI still had the kind of signature and hitting power of an armored force. Nothing very subtle about that. The enemy would most certainly notice the warships coming into orbit, followed by the massive signature of the MI hitting the atmosphere. To the MI that doesn't matter because they hit the ground fighting. Contemporary paratroopers can't do that. They have to secure their equipment, find their teamates, form up, check their location, and so on before they can even begin to fight. Any time paratroops have jumped into a prepared and entrenched enemy they've been cut down or captured. Meanwhile when dropped in an enemy's rear the lightly armed paratroops can use their advantage of surprise to wreak massive damage on the enemy's support and command and control systems.

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