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Deploying parachute

  1. Feb 10, 2016 #1
    Is it possible to deploy parachute at 30000 feet altitude
     
  2. jcsd
  3. Feb 10, 2016 #2

    Ranger Mike

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    yes..if you ca nstand the -50 degree F temperature and pre-breather Ox for 30 minutes before you jump
     
  4. Feb 10, 2016 #3

    cjl

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    Sure. Parachutes are deployed at that altitude all the time. If you intend it to be a manned parachute, there are some concerns with survival in the cold, oxygen-poor environment, but that's an entirely separate concern.
     
  5. Feb 10, 2016 #4
    How it is possible at heigher altitude it will burst
     
  6. Feb 10, 2016 #5

    cjl

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    What do you mean "burst"? A parachute isn't an enclosed object, so it can't really burst...
     
  7. Feb 12, 2016 #6
    I'm quite sure that space ships re-entering earths atmosphere deploy chutes higher than that.
     
  8. Feb 12, 2016 #7

    Ranger Mike

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    why would you risk deploying a parachute in thin air? You only increase risk of a partial or total malfunction. Considering the fact that a personal parachute will properly open after dropping 200 feet, it makes no sense to open a parachute at altitude. The parachute is not steerable ( multi canopies required for heavy drop) so when you pop the chute 25 miles up the payload can wonder all over the sky and land who knows where. You need to glide to 1000 AGL (above ground level) and pull the rip cord. if memory serves me well, Apollo command module re-entering the atmosphere at 243 mph used drouge chutes at 24,000 feet to slow the capsule to a speed where the deployment of the three main chutes would not rip the nylon or shroud lines, i think the chutes popped at 10,000 feet and the capsule splashed down i n the ocean. At 10,000 feet you are not going to drift off course too much. Again you can not steer these three large canopies.
     
    Last edited: Feb 12, 2016
  9. Feb 12, 2016 #8
    I need to know because we are designing a safety capsule inside a flight .so that when the flight destroys safty capsules will keep pasengers from explosion. For acheiving stability in capsule deploying parachute is needed
     
  10. Feb 12, 2016 #9

    Nidum

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    Do some sums . This will point you in the right direction to start off :

    https://www.quora.com/Why-dont-airplanes-have-giant-parachutes-attached-to-them-to-save-the-plane-and-its-passengers-in-times-of-emergency [Broken]

    There is huge amount of information about parachutes , ejector seats and escape pods on the web .
     
    Last edited by a moderator: May 7, 2017
  11. Feb 12, 2016 #10

    cjl

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    There are a lot of good reasons to open chutes higher than that - often, there will be small stabilizing chutes to keep an object in the desired orientation while falling or chutes designed to lower the terminal velocity so that further chutes can be opened with less shock. In addition, large chutes can take several thousand feet to open properly, especially if you have several stages of reefing to cut. The Apollo parachute opening sequence began at 25k feet for example. For an even more extreme example, most military aircraft ejection systems involve deploying a small stabilizing parachute shortly after ejection. This is even true for the SR-71, where after ejection, a small parachute would be deployed at supersonic speed at 80k+ feet altitude.

    All that having been said though, I don't think parachute based safety capsules for commercial flights are feasible. The added weight would be very substantial, decreasing passenger capacity dramatically (and thus increasing cost per passenger), and in-flight explosions or disasters are quite rare. The return on investment simply isn't there.
     
  12. Feb 14, 2016 #11
    I remember when I was skydiving there was considerable talk about opening parachutes at high altitude. The material used in parachutes, at least the sporting variety, are made of rip-stop nylon. They are obviously slightly porous so that you get a controlled descent, this is called porosity. At higher altitudes the porosity is less and your freefall velocity higher, and i think that means the opening will be harder. At least that was the folklore of the time.

    Cheers
     
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