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Stratospheric Skydiving
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 a...uh...active way to spend your time.
Skydiver team: "We should have checked the space weather"
Russian officials: "We thought the stratosphere were belong to us at that time !!"
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 (www.aopa.org) that someone is trying to get a glider to 100,000 ft.
I'll stick to playing at 5-10,000 ft thanks.
Erlang Developer and podcaster
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. :)
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He experienced temperatures as low as minus 94 degrees Fahrenheit and a maximum speed of 714 miles per hour, exceeding the speed of sound.
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According to what I have read elsewhere, and as cited at PBS, Kittenger did go supersonic during his jump.
OpenSourcerers
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.
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I think there is a world market for maybe five personal web logs.
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.
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{Network engineer in Chicago--looking for work!}
The article was from November:
http://slashdot.org/articles/00/11/02/0411221.sht
Have fun and don't hurt yourself.
Nope. The air pressure is higher on your body when in the torpedo position (since the same force must be exerted on a smaller frontal area to support your weight), but the violence in the pressure change wouldn't be any greater at high altitude than at low. I contend that maneuvers would be no more dangerous at high altitude rather than low, even though the jumper is traveling faster.
Why yes, I AM a rocket scientist!
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.http://www.allstar.fiu.edu/aerojava/mach.htm
Why yes, I AM a rocket scientist!
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?
Why yes, I AM a rocket scientist!
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.
--- It is not the things we do which we regret the most, but the things which we don't do.
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.
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.
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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.
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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.
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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.
The rule of thumb accounts for that so that your perigee will end up around 0 to 50 nautical miles. Orbital mechanics says if you make your deorbit burn at a given point, it will lower the perigee at a point 180 degrees opposite where you made the burn.
"2 feet per second per nautical mile altitude" is not meant to be exact but it does take into consideration that you don't need to lower the perigee all the way to 0 altitude. It's just a back of envelope sort of thing. I'm sure Capt. REFSMMAT would approve of it, though ;-)
how can you even think of doing something that's not 100% safe
Hehe. So frustrating. So true. "Aww come on you guys, it's not rocket science..... err....uh...actually...never mind."
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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.
there are 2 kinds of people. those who divide people into 2 kinds, and those who don't.
The guy planning to do the jump/dive was on 99x.com ( 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? )
--Chemguru
--Chemguru
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...)
A sonic boom from air passing over a surface at greater than Mach 1 two inches from the ear might well be a great way to go deaf. Of course, it might be worth it to him to experience something that nobody else ever has.
WARNING: there is a trojan on your
Some of what I say is fact, some is conjecture, the rest I'm just blowing out my ass...you guess.
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.
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.
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.
I thought that falling objects could not fall faster than terminal velocity(230 something mph) unless acted on by another force, besides gravity. The article says that he will be falling at 800-900 mph. So, whats really going on? Is this right or am I retarded?
IAAS. As you fall, the air molecules that you collide with provide an upward force that counteracts gravity. More specifically, you provide a downward force on the air molecules, and because of Newton's action-reaction law of physics, the air molecules provide a like force back on you. Faster fall rate = more air molecules = more force. The forces balance out at terminal velocity. Since there are less air molecules Way Up There, you'll have to travel faster to get enough air molecules to counteract gravity - hence the reason TV is higher at higher altitudes. 800-900 mph up there, 120 mph closer to the planet.
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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..
Stupider like a fox! - H.S.
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.....
Note the orange box in the picture -- clearly there to hold his huge balls.
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Death to Vermin.
"Trust me - I know what I'm doing."
- Sledge Hammer
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
stainless steel
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?
Yes I did read your original post, and your sources ;)
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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.
-Kraft
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-Kraft
Live and let live
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.
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.
"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.
Ceci n'est pas une sig.
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.
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.
Scratch-o-Matic
Evil is the money of root.
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For sale: parachute. Once used, never opened, small stain.
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?
- the-crater insurance
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
Yoinks.
-- there is no point in pulling the pud... if you do it right.
This guy had some serious intestinal fortitude.
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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.
-Kraft
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-Kraft
Live and let live
As he descends the air density will pick up and he will slow down.
Chris Kuivenhoven is a thief, beware
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
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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.