Re: Re: starship-design: One way (again...)

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

Kelly St wrote:
>In a message dated 12/9/97 1:15:09 PM, kuo@bit.csc.lsu.edu wrote:

>>L. Parker wrote:

>>>Several months ago I made the statement that there is more incentive to 
>>>stay in space where power is cheap, resources are plentiful and 
>>>(comparatively) easy to get at. So I really have a hard time seeing why 
>>>anyone would want to go to another star just to _settle_ on a planet.

>>Resources on a planet are much more plentiful than in space, and
>>much easier to get at (for the inhabitants).  Furthermore, building
>>habitats on a planet is much simpler than in space, because you get
>>radiation and space debris shielding for free.

>Actually most of our richest ore vains are from old crashed asteroids.

Not all resources are ore veins.  Here on Earth, there are resources
like sand, bricks, water, and air--none of which are more plentiful
in ore veins.

>Materials inspace are FAR more avalible, and orders of magnitude higher in
>purity.  Stainless steel for example can be mined in almost finished alloy
>form, oil and petrochemicals can be scooped up by the montain load etc.

In order to build a habitat, you have a lot more diverse resources
than just something to build a big tin can.  A place to live can
be built out of rock, or cement.  The primary other things you need
to live are oxygen and hydrogen.  On some planets this is a problem,
but on others it isn't.

>Space is nowe considered a far more viable location for an industrial soceity
>then any planet.  Read some of the old O'neil books.

Ah, never trust anything you read in a book.

>>>If you bear that in mind, and look at the mission profile as one that is 
>>>designed to begin building an outpost in orbit in that system for the 
>>>purpose of continuing exploration and creating a spaceborne infrastructure 
>>>for follow on missions, only some of which might be concerned with actually 
>>>landing on a planet, then it is not a one way mission. Nor is it exactly a 
>>>colonization mission.

>>IMO, this mission is still too ambitious for a first manned mission.
>>A first manned mission cannot expect to get _any_ resources from the
>>target system, because that first system will be the planetless Alpha
>>Centauri system.

>How do you know their are no planets?  We certainly have no more then guess
>work to go by know.

There _might_ be planets, but we don't have any reason to expect there
are any.  What's more, we have a good reason to expect that a binary
star system will swallow up anything like a planetoid due to eventual
collision with one of the stars unless it is either very close to one
of the stars or very far from both.

>Further if the system was empty their would be no reason
>to send an expidition.

Yes there would be.  We have the opportunity to seriously study a
star system radically different from our own.  Doing so will
bootstrap our knowledge of innumerable other star systems.

>>I don't think an unmanned flyby probe would be able to find usable
>>resources even if they were there to be found (because it would
>>lack the human creativity to recognize and scientificaly interpret
>>something unexpected).  With the 8 year two-way time delays, I
>>don't think an unmanned 1-way probe would work out either.

>>If there are resources to be exploited, then a 1-way manned mission
>>is the way to find it.

>You want to send people on a expidition dependant on local material, before
>you know their are anylocal materials!!!!  Thats crazy!  At least the
>Kamakazis knew there were americans to die killing.  By your statments you
>expect to send a crew and possibly have them get there find nothing their to
>look at or use?

They are not dependant on local material, and their primary purpose
is not to look for resources.

However, it's a good secondary purpose, because they are our best
means of determining if any resources are available.

>>>It is a team of scientists, and engineers and technicians with a definite 
>>>purpose - build a fully self sustaining outpost in orbit around another 
>>>star. Once they have done that they can then build power stations to 
>>>produce more fuel so that 2-way travel becomes more practicable.

>>I think that we can send them there with the hope that they'll find
>>something they can turn into something useful, but trying to build
>>power stations from the hydrogen and helium of Alpha Centauran
>>solar winds is trying to squeeze water out of graphite.

>>Our best hope would be if their Oort clouds had useful substances
>>and/or there are unexpected useful planetoids.  I don't think we'd
>>be able to get more than a cursory glance at these things before
>>going there ourselves, though.

>We should be able to image thing in the star system down to atleast a few
>meters resoultion from Sol.

Unlikely.  Even if we managed to get VLBI working at visible
wavelengths, LBI and VLBI do not increase sensetivity.  This
causes severe problems for searching for planetoids in the
Alpha Centauri system, because if there are any they are
either so close to a star that they are lost in the glare or
they are so far from both stars that they aren't very bright.
Furthermore, low albedo surfaces will imply even lower brightness.
-- 
    _____     Isaac Kuo kuo@bit.csc.lsu.edu http://www.csc.lsu.edu/~kuo
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