Ares I launch three

Discussion in 'Space & Aeronautics' started by Dyna-Soar, Dec 30, 2008.

  1. Dyna-Soar

    Dyna-Soar Member

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  2. NYC Irish

    NYC Irish Member

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    very cool...

    What a great hobby to have eh?

    John John
  3. Cut 'n' Paste

    Cut 'n' Paste Ex-pat

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    Question

    Hello.
    I was interested to watch the video. Pity it ended with damage to the rocket.
    I'm intrigued by the diagram above. There's a big space between the two engines! Now, I've always thought that it was necessary for the two stage engines to be in contact for ignition of the second stage. If you've got some way of getting ignition with this arrangement, I'd be interested to hear about it.

    Graham
  4. Dyna-Soar

    Dyna-Soar Member

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  5. Mike_BAR

    Mike_BAR American Rocketeer

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    Graham,

    Gap staging can work with the motors separated up to 12 inches. This was first published by G. Harry Stine in The Handbook of Model Rocketry.

    The above link to Keven Wickart's website is good. In addition, you can find more information about gap staging at the Apogee Rockets website, along with some clear diagrams. See links below.

    Regards,
    Mike


    How Multi-Stage Model Rockets Work

    Source website:
    Model Rockets from Apogee Components


    Handbook of Model Rocketry 7th Edition
    2004. By the late G. Harry Stine and Bill Stine.

    Source webpage:
    National Association of Rocketry Technical Service

    Source website:
    National Association of Rocketry
  6. Shin_kazama

    Shin_kazama Member

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  7. Mercsim

    Mercsim Member

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    How good is your math? You need to break it up into pieces and calculate the area of each one. Then you need to do a moment calculation from a reference point to calculate the center of pressure. This should be about 1 diameter (the largest one) BEHIND the CG.

    Another way is to cut out a flat accurate representation of the projected area (shadow) like in your drawing above. You can balance this flat model to get the rough CP. Once again this should be 1 diameter behind the CG.

    Remember arrow; rock in front, feathers in back...

    Hope this helps. Here is an example of the calculations


    1/8 Mercury Redstone Plans

    Scott