Re: starship-design: Re: The Great Debate

[kuo@bit.csc.lsu.edu (Isaac Kuo)]

L. Parker wrote:
>On Tuesday, December 09, 1997 10:57 AM, Isaac Kuo 
>[SMTP:kuo@bit.csc.lsu.edu] wrote:

[about the theoretical market for a massive amount of beamed power]

>> The affordability of the powerful deceleration leg fusion rocket
>> (that we can afford it at all) suggests we have similar fusion
>> power generation capability which is relatively affordable.
>> Given the plentiful inexpensive energy everywhere, who's going
>> to need beam power?

>I don't really care which you use, but there is a small flaw in both of 
>your reasoning here. The FUEL for the fusion rocket (or power plant) comes 
>from somewhere, which requires energy to extract. In the case of an 
>antimatter rocket, we have proposed building orbital power satellites to 
>power giant cyclotrons (or whatever better device we come up with) for the 
>sole purpose of manufacturing antimatter so that we can use it to produce 
>fuel. The energy always has to come from somewhere, in this case, solar 
>radiation -> antimatter -> nuclear radiation.

Umm...this isn't the case of an antimatter rocket.  We're talking about
the fuel/sail concept with a fusion deceleration rocket.  The question
is how much of a benefit is possible from selling the power from the
beam satellites after they're done acceleration the starship.  This
is very speculative, but it's worth thinking about anyway because the
overwhelming majority of the cost of the fuel/sail starship is the
cost of the beam satellites (which mass at least thousands of times as
much as the deceleration fuel and IMO make it cost at least thousands
of times as much).

[...]
>One of Isaac's 
>arguments is the inefficiency of the beamed power concept over interstellar 
>distances, and he is right. But within the immediate area of the Sun it is 
>very efficient and far cheaper than standard fission/fusion.

>So for local power, Kelly is right (sort of) and for interstellar 
>propulsion, Isaac is right (sort of).

I think you're a little bit confused about what we're discussing here.
Neither of us are proposing using beamed power over interstellar
distances, and Kelly isn't proposing using the beams to accelerate
the starship in the immediate area of the sun (it's being used for
a starship's low acceleration run).
-- 
    _____     Isaac Kuo kuo@bit.csc.lsu.edu http://www.csc.lsu.edu/~kuo
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