From: Michael M. Butler (butlerj-nkmail@comp-lib.org)
Date: Fri Aug 14 1998 - 00:06:56 MDT
Spike: that was actually Phil Witham paraphrasing/agreeing with Bob Truax,
not Yours Truly. :)
MMB
At 22:58 8/13/98 -0700, you wrote:
>Michael M. Butler wrote:
>
>> >... To get into orbit cheaply, you need to build your rockets Big and
Dumb...
>
>yup. looks like there are three showstoppers for well funded amateur
groups.1.
>regardless of how big and how dumb a liquid rocket is, one still mustpump
a high
>volume of cryogenic liquids to combustion chamber pressure .
>
>2. generally rockets have a high l/d problem: they are tall and skinny,
in order
>to
>reduce atmospheric drag. so, there is a great deal of science in the
structural
>dynamics of the system. this was a major problem in the early days of
>rocketry.
>
>3. guidance and control: this is a very complicated problem generally,
requires
>
>a sophisticated feedback mechanism with thrust vector control by means of a
>steerable nozzle for instance.
>
>there are a lot of different concepts all going under the name roton, some
>workable,
>others not. i have only recently come to appreciate this. the beauty of the
>simplest
>roton system is that it solves all three of the above, sort of.
centrifugal force
>pumps
>the cryogens. you need not have high l/d, since you can give away some
>performance.
>the inherent stability spinning about an axis with high moment of inertia
obviates
>
>a flight computer. there are still some difficult problems, such as how
to turn
>the
>vehicle, but i have some ideas. a roton could be conceive which has very few
>moving parts.
>
>like apple computer, the roton concept is not really being sold right, in my
>opinion.
>when the rotoners say that it might raise payload at 1/5 the cost of
conventional
>rockets, they should perhaps make it clear that what is meant is a system
that
>raises payload at 1/10 the performance at 1/50 the price... either way,
the roton
>
>is within the reach of sophisticated amateurs and underfunded entrepreneurs.
>spike
>
>
>
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