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Aerodynamic/hydrodynamic drop pod

  1. Aug 28, 2012 #1
    First, this is just something I've wondered for fun....not serious, and just wonder if if the laws of physics make this possible.

    Would it be possible to create a drop pod shape such that a person could be dropped from a helicopter from a high altitude and have it hit the water (ocean) such that the occupant experiences an acceptable deceleration rate then it bobs back to the surface?

    Thanks,
     
  2. jcsd
  3. Aug 28, 2012 #2

    Bobbywhy

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    Gold Member

    72Zorad, Although I have no suggestions to offer, the device you are asking about just might prove useful for rescue swimmers who jump out of helicopters to save lives. Here is an excerpt from the wiki page:

    "Water entry shock
    Although water entry close to the surface is relatively uneventful, the density of water makes it harder for it to move out of the way when penetrated at high speeds, as occurs when jumping into water from great heights.

    Mild bruising to being knocked unconscious can occur from very high jumps, especially if entry angle can not be controlled and the jumper is burdened by coiled rope and other heavy rescue equipment. In some situations the rescuers can themselves need to be rescued if they are injured by making a very high jump entry into water.

    Generally rescue jumpers try to get as close to the water surface as is practical before jumping out of the rescue vehicle. In ocean rescues during intense storms, helicopters often must stay high to keep clear of large ocean waves, which also have very deep troughs. In these conditions, the jumper tries to time his jump to occur at the crest of the wave action."
    http://en.wikipedia.org/wiki/Rescue_swimmer
     
  4. Aug 28, 2012 #3

    K^2

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    Such a shape obviously exist. A very long and narrow cone would do just that. Question is, whether one can be created of practical size, and that's very unlikely. It will have to be comparable in size to the length of safe deceleration path. So while it can be somewhat smaller than similar device for impact with hard ground, it's not going to be enough to make it practical.

    Your best bet for falling from great heights is landing rockets. These have been used to drop military equipment. Might be possible to make something that can bring a human down safely.
     
  5. Aug 28, 2012 #4
    My thought was a thrill ride for those crazy people who base jump and such. Recently saw a show where a guy used one of those sailing suits to land in a pile of boxes without a parachute. Last guy who tried that mixed the boxes and died. This could another one of those first. First to intentionally survive a free fall to earth (intentionally) without a parachute.

    Mind you, not me....I have no desire to leave the planet without a dependable engine, wings, and good pilot to bring me safely down.
     
  6. Aug 29, 2012 #5
    You don't need a pod why not use a bungie rope.
    Helicopter calculates height to ocean,length of rope selected,person dropped to water.
    The dissconection of the rope once the diver feels wet feet.
     
  7. Aug 29, 2012 #6
    rotor blade, bungee cord, high wind, heavy sea, what could possibly go wrong?
     
  8. Aug 29, 2012 #7
    Now't if you are dissconected at the helicopter end.
    Cutting the rope at the other end, that would be asking for trouble.If you consider a pod drop and the broken bones involved with that I would rather take my chances with a bungee and someone reliable on board.
    Second thoughts it might be a good idea to be inside a pod as well to stop the cord hitting you on your head.
     
    Last edited: Aug 29, 2012
  9. Aug 29, 2012 #8
    I believe NASA was working on a project to deliver small payloads from the space station to earth. It was to be an unmanned pod that could be guided to its destination from orbit. The concept is extremely useful for space travel. Imagine if a single person could be dropped from the space station!
     
  10. Aug 29, 2012 #9
    My hypothesis is that the bungee cord will contract and fall, converting its elastic potential energy and its gravitational potential energy to kinetic energy and deliver it to the swimmer.
     
  11. Aug 29, 2012 #10
    Makes sense, see second thoughts post 269.
     
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