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Stratospheric Skydiving

Posted by Hemos on from the sonic-boom-from-the-body dept.

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.

6 of 117 comments (clear)

  1. Re:Already Been Done (Project Excelsior) by CoreDump · · Score: 4
    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.

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  2. Joe Kittinger been there, did that by Kraft · · Score: 4

    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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    Live and let live
  3. Re:Breaking sound barrier? by eXtro · · Score: 4
    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.

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    Chris Kuivenhoven is a thief, beware

  4. Already Been Done (Project Excelsior) by CoreDump · · Score: 5
    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

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  5. Re:Stratosphere? by ASCIIMan · · Score: 5
    Corrections:
    • 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)
  6. I dunno about that by Prof_Dagoski · · Score: 5

    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.