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Re: starship-design: Re: Re: regarding fuel expenditures
L. Parker wrote:
>On Friday, November 14, 1997 4:41 PM, KellySt@aol.com
>> You really don't need to do the sligshot manuvers around Earth and the
>> A star Ship needs such powerfull engines, and has to boost to such high
>> speeds, that the gains from these manuvers are a joke.
>Not quite true, that particular orbital maneuver has already been
>researched thoroughly, we have even discussed it here.A
That's not the point. The point is that the potential extra benefit
is a ridiculously small amount compared to a percent of c in delta-v.
In fact, the disadvantages are such that they overwhelm any advantage.
>It is called the
>"Powered Perihelion Maneuver" and is capable of generating up 400 g's of
>thrust initially. The drawback of course is that this thrust is more than a
>human can withstand and that it tapers off as your course takes you further
>from the sun.
Even without the human limitation, strengthenning an unmanned probe
for 400 g's will increase its mass by at least some small fraction.
This will make it require _more_ fuel, not less.
>Due to human limitations, the highest cruise velocity obtainable without
>further boost from some other sort of engine is only 0.003 c. Something
>akin to Forward's Starwisp on the other hand, could be accelerated to over
>0.3 c in only a few days and even faster using a combination of this
>maneuver and follow on beamed power from an orbital power satellite.
It would not be significantly faster. And that's the point.
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