keith.kepner@us.pwcglobal.com wrote:
> Would it be cheaper to shoot it off into space from atop a mountain than at
> sea level?
>
> The rail gun? You may as well forget designing one if there isn't a
> "vaporizing option". Seems those surveyed balk at the prospect of a messy
> cleanup.
>
>
To get anything into orbit, it has to meet and maintain 'escape
velocity' after it has reached its orbital path. For LEO, this is
approx. 7 miles per second. If you try to orbit an object by rail gun
(rather than rocket), all of the velocity comes from the initial shot;
the object immediately begins to decelerate (due to drag). In order for
the object to still be traveling at 7mi/s once it reaches its orbital
distance, it has to be fired at a much higher velocity than 7mi/s. If
your rail gun in on top of Mt. Everest, there is much less air and much
less drag. If you fire from thick, soupy, hot, muggy Florida not only
will you need a MUCH higher initial velocity, but the drag (friction) on
your object will create a lot more heat than a high alititude shot. You
will be creating an incandescent meteor in reverse.
--ronan
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