From: gary@ke4zv.uucp (Gary Coffman)
Newsgroups: sci.space,alt.sci.planetary
Subject: Re: Lunar "colony" reality check
Date: 9 Nov 92 16:09:17 GMT
Reply-To: gary@ke4zv.UUCP (Gary Coffman)
Organization: Gannett Technologies Group

In article <BxEt07.G32@techbook.com> szabo@techbook.com (Nick Szabo) writes:
>Lunar "colony" reality check:
>
>* The moon has no significant sources of hydrogen, nitrogen,
>  or carbon.  Wishful thinking about polar volatiles or
>  scrounging solar wind particles are hardly significant.

We don't *know* that, no through mineralogical survey has ever been
done. We know such materials aren't as common on the exposed surface of 
the Moon as on Earth, but they don't have to be sufficient to support
a planetary biosphere, only sufficient to support a modest colony.

>* A livable atmosphere is mostly nitrogen, not oxygen.

*A* livable atmosphere is mostly nitrogen, but not *every* livable
atmosphere is mostly nitrogen. All that's required is a partial
pressure of about 4 PSI oxygen, and if you want a higher atmospheric
pressure, some relatively biologically inert dilutant gas. Helium
works, as do a few other gases.

>* Plants and animals need copious amounts of hydrogen, nitrogen,
>  and carbon.

*Adult* organisms need approximately their body weight in these
elements. A stable population recycles the materials on the timescale
of an organism lifetime.

>* There is no affordable way to crack oxygen out of lunar
>  rock or to recycle it.  This would cost, at bare minimum,
>  tens of millions of dollars per astronaut per year.  

100% recycling is presently uneconomic, but a large fraction can
be recycled economically. And, there are experimental processes
running *today* on lunar simulant materials that extract oxygen 
economically at the make up percentage required.

>* Because of transportation costs for recycling equipment,
>  recycling on the moon is far more expensive than recycling on 
>  earth.  Even on earth the best attempt at building a livable, 
>  working biosphere masses hundreds of thousands of tons and leaks 
>  over tens of tons of air per year.

The average nuke missile sub masses about 6,000 tons and supplies the 
needs of a crew of 170 for three months. Most of that mass isn't needed
on the Moon since dives to 1000 feet aren't required and torpedos
and ICBMs aren't in great demand on the Moon. Biosphere II tried to do 
recycling solely with biological materials. That is inefficient, overly 
complex, and has proved a failure. Mechanical/chemical scrubbers, vacuum 
distillation systems, and the like are much more compact and efficient. 
One thing the Moon, and any body in space, has available in nearly 
unlimited quanities is energy in the form of solar heat. With nearly 
unlimited energy, lots of problems become much easier.

>* Hydrogen is extremely innefficient to transport from
>  earth.  The stoichiometric volume of LH to make water is
>  _larger_ than the volume of oxygen; huge amounts will
>  be wasted on tankage.  Much of the LH will leak before
>  it can be used; it's extremely difficult and expensive
>  to store even for the few days trip. 

Which is probably why no one is proposing to ship liquid hydrogen
to the Moon in large quanity.

>* The annual per capita consumption of water in the
>  U.S. is over 500 tons.  In this as in many other
>  areas, the "colony" will be living in abject 
>  poverty despite the $billions spent on its
>  construction.

Since the average American uses more water to water his *lawn* than
most of the rest of the world uses in total, this only says that
large lawns won't be popular on the Moon.

>* It takes more than a rocket payload full of hydrogen
>  to make the water needed by industry.  If we're to have any 
>  significant manufacturing industry in space, we're going to need 
>  tons of volatiles.  For example, here is the water used to make 
>  a few kinds of products on earth:
>
>			gallons/unit
>			------------
>finished steel, ton	40,000

Have you ever visited a steel mill? The water is used in a single
pass cooling system for the rollers in the sheet and tube mill,
and for quenching billets. That's not the only way to do it. 
*Modern* mills, like Nucor's mills, use very little water, and
that in closed loop cooling systems.

>automobiles, unit	12,000

Most of the water used in auto manufacture was in the paint prep
system. That's been replaced with closed cycle vapor phase solvent
prepping in modern plants. The rest is used for cooling, again, thanks
to the clean water act, that's now closed loop as well.

>trucks, buses, unit	20,000

Ditto.

>* There is no signficant economic resource on the moon. 
>  Revenues as a percentage of costs will be 0%.

With the speculative exception of He3, there is no mineable
resource on the Moon, that we know of, that can be economically
exported to *Earth*. However, manufactured products of aluminum
and titanium suitable for use in *space* can be produced as well
as bulk aggregate for concrete-like structures and for shielding.
A mass driver on the Moon can loft bulk materials to orbit cheaper
than those materials can be lofted from Earth. Building the mass
driver would be expensive, but operating costs would be low.

The most important resource exportable from the Moon, however, is
massless. That's knowledge. The Moon is a near ideal platform for
very long baseline interferometry at radio, optical, and ultraviolet 
wavelengths, something that's very difficult in a free floating 
micro-gravity environment unshielded from Earth radio sources and
not solidly anchored against torques. It's also a safe place to do
high energy physics, and biological experiments too hazardous to do
on Earth.

>* SSF bare-bones habitat operations costs will be $2 billion
>  per year.  Scaling for transport costs gives over $10 billion
>  per year for a bare-bones lunar "base".   Redesign will cost
>  even more than SSF cost,  since industry has no reason to
>  participate beyond the usual NASA-contractor mode.

Almost all of that cost figure for SSF is transport cost based on
Shuttle. To return to the Moon to stay, we're going to need a transport
system beyond Shuttle. Since Shuttle will be going to LEO anyway for 
crew rotation and supply of SSF, with less than a full payload on most 
trips, it should be possible to piggyback crews and some supplies for 
the Lunar base on the trips for little incremental cost. Follow ons to 
the Shuttle should be cheaper to operate, lowering incremental costs 
even more.

Now we need a lunar transfer system to shuttle between SSF and the 
Lunar base to complete the system. That's a much easier problem since 
the remaining energy cost is low to get from LEO to Lunar orbit. An 
efficient, high ISP system such as electric ion rockets can handle that,
or a nuclear system could be used without fear of contaminating
Earth. Solid rockets based on Lunar powdered aluminum could also be
used, as could mass driver launched return vehicles.

>* Calling a few astronauts huddled in a Winnebago a "base" is
>  a major exaggeration.  Calling it a "colony" is an abominable 
>  misuse of the word.
>
>There are dozens of other pathways to space colonization.
>Fixation on obsolete concepts like the "lunar base" and oxymoronic
>concepts like the "lunar colony" is one of the main reasons why
>the space colonization movement lies mired in failure.

With nabobs of negativism like you around, why should we be surprised? :-)
The problems you paint for a lunar base are mostly similar to the
problems of placing a colony *anywhere* in the solar system. They
are primarily issues of sustainable recycling and transport. Exporting
materials to *Earth* is not a path to economic viability for any space 
system currently envisioned. The market for materials to be used in space 
is small and growing very slowly. Knowledge will remain the only viable 
export to Earth for many years, probably centuries, to come.

Gary
Newsgroups: sci.space,alt.conspiracy