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Unravelling Rocket

A rocket that unravels as it flies.
(+1, -1)
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They make multi-stage rockets because the extra sections drop off as it flies to reduce dead weight.

The casing of the unraveling rocket would be spiral wound and would behave somewhat like a TOW missile as it unspools...Just unravelling the extra weight as it flies, rather than dropping off sections.

ShawnBob, Oct 12 2012

Piston_20Rocket [spidermother, Oct 31 2012]

Case bonding, and why it's usually not done http://www.nakka-ro...y.net/casebond.html
[spidermother, Nov 01 2012]


       What's the propellant?
8th of 7, Oct 12 2012

       Hang on a moment. Rockets normally burn from the bottom upwards. The bottom end is important, because it carries the nozzle. So...
MaxwellBuchanan, Oct 12 2012

       It's propelled by wool dust.
normzone, Oct 12 2012

       [MB] this would of course work on your syringe-rocket, except for the bit where it doesn't work.
FlyingToaster, Oct 12 2012

       (lyrics) "If you want to destroy my sweater, pull this thread as I walk away..."
normzone, Nov 01 2012

       In order for the combustion chamber to be strong enough, the drag due to unwinding would be huge.
MechE, Nov 01 2012

       The rocket would be built of solid fuel, with the nozzle climbing up the spiral body of the rocket, consuming it and turning it into pure thrust as it went.
bungston, Nov 01 2012

       Most solid fuel rockets don't burn bottom-to-top like that (it's called the end burner configuration, and it's considered difficult and dangerous). But it can be done.
spidermother, Nov 01 2012

       Well, if they don't burn from the bottom up, they burn from a central hole out. Either way, a rocket needs to keep its arse.   

       Actually, I quite like [bungston]'s idea. If you had a solid stick of propellant, with a cap on the top and a cap on the bottom with a nozzle, and with some very very very powerful springs holding the two together... no, it still wouldn't work but it's a nice idea.   

       If it were a liquid rocket, you could make the tanks telescopic so they'd shorten as the fuel was consumed. But then you wouldn't be saving any weight.
MaxwellBuchanan, Nov 01 2012

       //if they don't burn from the bottom up, they burn from a central hole out// Very often, the grain burns from all sides, including the outer surfaces (but often including a central hole). Mainly because if you design it to work any other way, a failure of the bond with the casing (or other means of preventing burning of the outside surface) greatly increases the burn rate, which is a Bad Thing.
spidermother, Nov 01 2012

       This I didn't know. Is the combustion of solid fuels at a similar temperature to that of liquid (lox/kerosene) mixes? Liquid rocket combustion chambers are usually actively cooled, but in a solid rocket the whole damned thing is a combustion chamber.
MaxwellBuchanan, Nov 01 2012

       //This I didn't know.// (Link) to the superb site where I learned this, and nearly everything else I know about small rockets.   

       Liquid rockets burn hotter, in general, which is consistent with their higher specific impulse.
spidermother, Nov 01 2012


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