From: ewright@convex.com (Edward V. Wright)
Subject: Re: Cost of lunar base
Organization: Engineering, CONVEX Computer Corp., Richardson, Tx., USA
Date: Mon, 6 Apr 1992 16:58:10 GMT
X-Disclaimer: This message was written by a user at CONVEX Computer
              Corp. The opinions expressed are those of the user and
              not necessarily those of CONVEX.

In <1992Apr5.154805.6222@ke4zv.uucp> gary@ke4zv.uucp (Gary Coffman) writes:

>Well, that's not totally dumb, but composting is not the most efficient
>way of supplying nutrients to a limited amount of plants when you look
>at the mass requirements. Modern agriculture uses artificially produced
>fertilizers because it's more efficient and cost effective to do so. 

Sure, but what is most efficient for a nation of 200,000,000 people
may not be most efficient for a colony of 500.  If a fertilizer plant
costs more to build and operate than a compost heap (and at that scale,
I think it almost certainly would), you'd use the compost heap.  The
compost heap also the adantage of being *much* less susceptible to
mechanical breakdown.

>There's no point in 
>throwing out good organic material. But the cost of generating the 
>biomass in the first place, just for clothing, doesn't make $ense.

That's true *if* you only get one batch of cotton out of that biomass.
But we're talking about a permanent colony here, so you would continue
to get crops out of it year after year.  Also, remember that biomass is
mostly water, and water is 8/9 oxygen by weight -- the oxygen can be
extracted from lunar materials, so only the hydrogen has to be imported. 


>It was the orginal poster who stated that *hand* spinning wheels would
>be manufactured on the Moon from native materials for making cloth. 

Nope.  The original poster (me), simply specified "spinning wheels."  The
"hand" part was your embellishment. 

>Those treatment procedures consume vast quanities of water here on Earth. 

Do they actually *consume* that much water, or do they simply use it and
expel it as waste that can be recycled?  Big difference.


>The fabric industry here on Earth is built up on a system of small job
>shops that depend on other shops to produce the materials they need and
>whose output goes to other small job shops that use the material they
>produce for the next step in the process. The overall operation *is*
>a multi-billion dollar system that depends on each step being performed
>properly. 

Again, the overall operation is a multi-billion dollar system because it
must produce billions of dollars worth of finished goods.  If all you
wanted to do was supply the needs of a 500-person colony, you wouldn't
try to recreate that whole system.  Simply scaling everything down probably
wouldn't work, either.  It's easy to think of reasons why something won't
work.  The challenge lies in picking the best technology -- and best does
not necessarily mean newest -- to do the job. 


>I consulted on the software for a machine that takes roll cloth and 
>turns it into finished uniform shirts. The complexity of doing that
>seemingly trival hand task by machine turned out to be very daunting.
>The shade marking subsystem alone involves an optical mapping of the
>cloth roll and a careful pattern layout program that minimizes waste
>while keeping all the pieces of the shirt the same shade. 

Cutting fabric from a pattern, even if you have to do it manually, is not 
nearly as labor-intensive as you make it out to be.  It never takes me
more than a few minutes to cut out even a complex garment; sewing takes
a lot longer.  Cutting a hundred garments from a stack of fabric takes
even less time than cutting a single garment by hand -- I've watched
this done.  It sounds like most of your problems came from the fact
that you were dealing with a continuous roll and needed to match
colors exactly.  It's much easier to keep things simple if you aren't
operating within the constraints of an existing system.

Another thing which must be considered is that many people consider
sewing, gardening, etc. to be fun.  You are going to have to provide
the colonists with some recreational opportunities in their off time,
and if they happen to be productive, so much the better.  


>>>Cotton is cotton. It can be recycled no matter where the source of the
>>>original fiber.

>>Really???  The only way I know of to recycle cotton is by growing cotton
>>plants.  If you know another way, please tell me.  Don't bother filing a
>>patent first, I'll take care of that. :-)  

>I guess you've never heard of the old and honored profession of rag picker.
>Much of the raw mat that is used in thread production is recycled fiber.
>Rags in better condition are still used for *patchwork* products. And
>rag fiber is still used for paper production. 

You're going to tell the colonists you want them to wear rags?  Sure, rags
can be used for cleaning, patchwork projects, etc., but there comes a point
where they're useless even for that.  Apart from stuffing toys and pillows
(which may be useless in 1/6-gee anyway), what do you do with them then?
You already said you believe thread production is impossible.  And paper
production is another can of worms: The lunar colony will be, perforce, an
almost paperless society, anyway.

>There's a world of difference between picking a ripe tomato and making
>clothing from raw cotton, both in the amount of labor involved, and in
>the real time skills required. 

You seem to be hedging.  You said before that neither of these things
could be done by teleoperators, because of the time delay.  What will
you concede next?

>Then there are the economics to be 
>considered. It takes an unskilled human on site about 10 seconds to
>select and pick a tomato for his table. Can you build, deliver, and
>operate a teleoperated tomato picker for the equivalent of 10 seconds
>of on site human hand labor? I think not. 

If that's true, then life support costs must be a hell of a lot less
than you've made them out to be.  You can't have it both ways -- claim
that the cost of supporting humans is so high that they must spend 100%
of their time doing "multimillion-dollar labor" and that it's cheaper
to pick tomatoes by hand.  Please make up your mind.

>On Earth, a mechanical tomato harvester, with an on site operator, costs 
>about $100,000 and masses about 10,000 pounds. It burns about 7 gallons 
>of diesel an hour. Can you design, manufacture, and deliver a teleoperated
>version for less?

Yes.  Because you're overlooking the matter of scale.  That mechanical
tomato picker is designed to pick more tomatoes in an hour than a 500-
person colony would consume in a month.  You might as well compare a
Boeing model 747 with a Piper Cub.


>Now remember our on site human tomato picker. If he is doing *other* work 
>worth $19,346.79 an hour, he can afford to have $251 tomatoes *shipped* 
>to him. Two a day represent only 0.32% of his salary. This is where the 
>tradeoff comes between home grown and imported goods.

This assumes he has other work worth $19,000 an hour -- which would put
him in the Fortune 500 very quickly.  *If* that person has labor that's
worth that much, the obvious answer is that he should do it, and pay
someone else to grow his tomatoes for him.  Add one more teleoperator
or human to the colony.

And since his body is going to be metabolizing that tomato and turning
it into carbon dioxide, someone else had damn well better be planting
*something* to absorb it!

  




Newsgroups: sci.space