Re: To Kevin and Kelly

[KellySt@aol.com]

>Actually there is a three way split.  Build, repair, carry spares.  In our
> >case the ship would need to be most concerned about mass.  I.E. you might
> >be able to make new I.C. chips, but the chips manufacturing equip would
> >weigh more then a 40 year supply of circuts.  Other things like exotic
hard
> >to manufacture alloys, composits, cermats, whatever, that the shuttles
> >would need.  Might require equipment too large to be carried along.
> 
> If we use self reproducing robots, a chip-backery should be on board
anyway.

Self reproducing robots are a long way off.  NASA did some studies that
suggested you'ld need human level A.I.'s to make a truly self suficent
system, and that assumed you could figure out the design.


> >Bottom line things will wear out.  When it comes to the point that the
> >frames, hulls, main power systems and such have reached their service
> >lives.  They are not practical to repair, they are scrap.
> 
> You can remelt the metal and make new plates.

Assuming that you want plates, can re-refine the metal to eliminate
contamination, have the metal manufacturing facilities, etc...

> >Unless your
> >proposing bringing all the equipment that every high end manufacturer
uses.
> 
> Yes, but how much equipment are we talking about, we need machines for:
> - Metal treatment
> - Plastic treatment
> - Semiconductor treatment
> - Glas treatment

There are whole industries dovoted to each of those topics.  They each have
tremendous amounts of specialization depending on what sybtype you want.  For
example Kevlar manufacture and composite aircraft layup, and lexan window
manufacture, both fit under "Plastic treatment".

Its not like you can just toss an aluminum can into a melter and cast a new
can out of it. In a lot of cases to 'recycle' the materials you'ld need to
break it back down to to the periodic table, then build it back up.  Thats
why so little real recycling is done now.  (Most materials in the U.S. that
are collected for recycling, wind up in special landfills where they are
stored as neatly separated garbage.)

> >Judging from the fact they work harder at maintaining there lowtech comune
> >life style then I do my high tech style, I'm not sure about your
> >comparison.
> 
> Using this analogy, won't the futere bring us a complete automatic world,
> where no one needs to work?

In theory it could, but historically we use most of the extra time to get
extra stuff out of life.  Amish in trade have far less, work harder for it,
and must be partially dependant on the developed world.  But they trade that
off in complex and inexplicable ways.

> >The military is probably a better example.  They need rugged equipment,
and
> >keep it for decades with limited upgrades.  But sooner or later it wears
> >out and has to be thrown away.
> 
> Yes, but then you have had more than enough time to build a replacement.

But they don't have enough people or equipment to do so.  So I doubt our
little (?) ship would manage it.

> >I totaly disagre with your assumption that a most social effort is
senceles
> >inovation for novelties sake.  Thing have to be replaced routinly. MOst
> >industries have to live with the fact of market saturation.
> 
> A lot of computers are not being replaced because they completely don't
work
> any more but just because the competion has faster ones. ----

And because the cost of maintaining the old ones are more the the cost of
buying the new one.


> >In theory thats true.  Reality doesn't live there.  The limits are
> >practicality.  You could break everything down to basic chemicals, ion
> >separate them to acceptable prurity, and mine that like ore.  But what
> >sence would that make?  Could you afford to bring along all that equiment?
> >Even if you could what advantage would it give you?
> 
> Isn't it possible to make objects with unmixed materials, so that the
> recycle-ability is enlarged much more, long enough to last the lives of the
> crew.

Only if the object can functionwith the simplified subset of materials.
 Obviously cutting edge or high performance equipment (superconductors,
reentry heat shields, aircraft or high streangth alloys, fusion reactors,
computer circuts, life support gear, medical equipment, drugs, etc...) can't
get by with such lowgrade materials.  So those systems would die as soon as
they ran out of spare parts.

Come to think of it even the rest might not make sence.  After all, unalloyed
metals wear out and corred FAR faster than alloys.  So the alloyed version
would outlive several recycled generations of the simpler primal metal
version.

> >The weight estimates were from the old stanford study.  which used mixed
> >soil and hydro farming.  (Hydro isn't that light, I mean water is heavy
> >too.)
> 
> That water you need always, even if you use frozen food.

Well you could freze dry it.  ;)  Actually you would freeze dry or dehydrate
a lot of it.  (40 year old damp flour?  I don't think so!)


Kelly