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Date: Fri, 22 Feb 91 01:40:35 -0500 (EST)
Subject: SPACE Digest V13 #186

SPACE Digest                                     Volume 13 : Issue 186

Today's Topics:
			  Re: Space Profits
		      Re: SPACE Digest V13 #165
			  Re: Space Profits
			     Re: dynasoar
       Commercially-funded Space Probes (was Re: Space Profits)

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----------------------------------------------------------------------

Date: 21 Feb 91 06:53:49 GMT
From: zephyr.ens.tek.com!tektronix!sequent!crg5!szabo@uunet.uu.net  (Nick Szabo)
Subject: Re: Space Profits

In article <9102202032.AA00483@ucbvax.Berkeley.EDU> TPM4017@PANAM.BITNET writes:

>...It seems to me that the ultimate profitability of space will be 
> determined by what space allows us to produce and carry back to earth. 
>,,,

These are very astute observations.  Space industry and settlement
cannot be undertaken unless it benefits Earth in a large way.  The
material, energy, and information resources of the solar system have
the potential to do this.  Keep in mind that producing information 
(eg weather satellites) and relaying information (communications 
satellites) are currently at the forefront of space industry.  Energy and 
materials could come to the forefront in the future.


>  In particular, I am interested in material manufacturing in space, and
>what might be mined on the moon or Mars.  What types of useful/rare
>materials might be/have been found on these worlds,

Good questions.  So far we haven't found anything like Sutter's Mill,
but there are many tantalizing areas.  Keep in mind that except for
the Moon and Mars, the surfaces of our solar system bodies have been
characterized only crudely if at all.  Henry will be quick to point out
that even the Moon and Mars could use quite a bit more exploration.
The following is based on our best contemporary scientific knowledge,
gained primarily through planetary exploration, astronomy, and
meteorite examination.

Two general categories of materials: those that can be exported to
Earth directly (eg precious metals) and those that can feed exporting
manufacturing industries (eg common metals and volatiles).

The closest bodies to the Earth energy-wise are an estimated 
100,000 near-earth asteroids of diameter larger than 100 meters.  
Some of these consist of native alloys of iron and nickel, with high, 
though probably unconcentrated, percentages of platinum-group metals.  
The precious metals alone can be worth tens of billions of dollars in the 
medium-sized (100 m dia) NiFe asteroids.  There are probably also small 
pieces of asteroidal material near the surfaces of the Moon, Mars, and 
moons of Jupiter.

Iron meteorites are small pieces of NiFe asteroid that have fallen to
Earth.  They sometimes contain tiny inclusions of diamond and other 
crystals.  It is not known if these are native to the asteroids or a 
product of reentry.

Simplifying things a bit, metals are only economical to mine if they occur 
in high concentrations, or "ores".  The bases of ore formation are
differentiation and hydrologic (water) processes.  The planet richest in 
both of these is our own Earth.  The only known body with greater 
geological differentiation is Io, which is dry.  Other Galilean moons like 
Europa contain abundant water, a fair degree of differentiation, and 
unknown low-gravity hydrological processes.  The rapid movement of these 
moons through the strong magnetic field of Jupiter introduces a unique 
new variable into ore formation, not unlike electrophoresis.  In general 
most bodies (the asteroids, Moon, etc.) have very low levels of 
differentiation, and therefore probably fewer and less concentrated ore 
formations than Earth.  Mars is somewhere in between, a low-gravity planet 
that once had running water.

The volatiles (hydrogen, oxygen, nitrogen, carbon, etc.) are absent
on the Moon and many of the asteroids.  They are abundant in comets,
Galilean moons, and some asteroids.  There is a small chance that tiny 
pockets of volatiles exist in the shadowed areas of the lunar poles.
Mars is rather dry but there could be significant water ice deposits 
underneath the surface.  In general as you move away from the Sun, 
the amount of volatiles increases, and the amount of silicates and 
metals decreases.  

Overall, our assay of the solar system to date is poor.  More 
astronomical observations, meteorite analysis, and planetary exploration
missions to the Moon, asteroids, Mars, Jovian moons, and comets are needed.


>how do we retrieve
>them, should we retrieve them, and is it practical to bring them back to
>earth.

Without going into details, the energy cost of moving a 100 meter 
asteroid or other large mass through a large delta-v is  prohibitive.  
Fortuneately we can "let the solar system do the work for us" -- through 
gravity well maneuvers and aerobraking.  An interesting new idea (OK, my 
idea :-) allows aerobraking to be widely practiced.  Given a budget of 
only 5 m/s machine-imparted delta-v, the opportunities for placing 
asteroids into Earth orbit via gravity well and natural aerobraking 
maneuvers are very few, while the opportunities for placing asteroids into 
collision courses with comets are high (billions per year, assuming we have 
discovered and tracked all of the asteroids and comets we believe to exist 
this side of Jupiter).  A few small nuclear explosives can vaporize 
the comet into a shaped double cone towards and away from 
the path of the approaching asteroid.  The angle of attack between the 
cone and asteroid can be fine-tuned through _large_ amounts of 
aerodynamic simulation to place asteroid in the desired trajectory, with 
a delta-v of up to 20 km/s, depending on the mass and velocity vector of 
the comet particles encountered.  Depending on the situation, the 
cometary aerobraking may place the asteroid in the final trajectory,
or the trajectory can be further modified by gravity slingshots and/or
aerobraking.

The environmental damage from a collision of even a medium-sized 
asteroid and Earth would be catastrophic.  Regulations should be 
established, requiring at least 2 m/s of machine delta-v capability be 
present at all times on any maneuvered asteroid.   Under no circumstances 
should an asteroid be maneuvered within 10 m/s delta-v of collision course 
with Earth.  It is best if asteroids are brought no lower than
geosynchronous orbit.


>...what manufacturing
>processes will gain an advantage by being performed in space as opposed
>to earth-based production?  

Let me pull out the handbook, _Scientific Foundations of Space 
Manufacturing_ (Mir Press, 1984), available in finer university bookstores
and engineering libraries.  Based on Soviet experience with drop towers,
sounding rockets, manned and unmanned orbital platforms.

The relevant differences between Earth orbit and surface are microgravity
and vacuum.  In other parts of the solar system, very high amounts of 
energy from sunlight and motion through Jupiter's magnetic fields may be 
made available in the more distant future.  

Among the processes the Soviets have played around with (there are
so many fascinating ones I'll just sort of read them off):

electron-beam welding
melting & solidification of metals
applications of coating to metal surfaces
stability of liquids under rotation
mass transfer in melt
crystal growth from solution
containerless solidification of eutectic
action of capillary forces
behavior of gas inclusions in liquid
brazing of metals
multiphase fluids/shadow method
dissolution & crystallization -- holographic measurement
semiconductors & glasses
alloys
electron-beam evaporation/deposition of thin films
electrophoresis
stefanov crystal growth method
interdiffusion
morphological stability of faces
production of foamed aluminum
mass transfer in gas phase
unidirectional solidification
single-crystal growth by mass-solvent method
liquid-phase epitaxy
sublimation on a seed
crystallization in a capillary
constitutional supercooling

acoustic & mechanical vibrations
electronic & magnetic fields

Take these processes, an asteroid, a comet, and large doses of 
thought and imagination, and the possibilities are, well, astronomical.

Manufacturing processes in space can sometimes produce materials of greater
purity or concentration than possible on Earth.  However, they still 
compete with Earth processes.  A case in point is the McDonnel Douglas 
project to manufacture the pharmaceutical erythropoetin using 
electrophoresis (charged particle separation) in microgravity during 
the mid-80's.  Before they could perfect the technique, the biotech 
company Amgen had figured out a way to produce erythropoetin at one 
gravity via genetic engineering.  Microgravity research continues to 
suffer from much higher transportation costs and longer turn-around 
times than Earth-based research.  For sufficiently high-value, low-mass 
products the impact of high launch costs can be minimal, but the impact 
of long turn-around times for experimentation is a serious disadvantage 
for all kinds of space manufacturing.

To sum up, we have many fascinating possibilities, and a lot to learn!


-- 
Nick Szabo			szabo@sequent.com
Think long-term, act now.

------------------------------

Date: 20 Feb 91 20:32:49 GMT
From: emanon.cs.jhu.edu!arromdee@umd5.umd.edu  (Kenneth Arromdee)
Subject: Re: SPACE Digest V13 #165

In article <CA79D2C880000062@BITNET.CC.CMU.EDU> 18084TM@MSU.BITNET (Tommy Mac) writes:
>         A) uses energy in any form for the organization of matter
>         B) experiences growth
>         C) reproduces
..
>unarguable position of the Gaia Hypothesis.  The only reasons not to accept it
>at face value are:  (as far as I can tell)
>1)  Gaia is childless
>2)  Our defenition of life is non-existent (Or so vague it's meaningless)
>3)  Our defenition of individual organisms is non-existent

4) In order to claim that functions by "parts of Gaia" are actually life
functions, you have to make analogies that don't _completely_ fit.  Sufficient
selection of analogies can be used to prove that anything is alive; this is not
a problem with the definition of life, but a problem with making excessive
analogies.

For instance, automobiles
-- use energy
-- experience growth (by performing functions for humans, in exchange for
   which the humans replace parts)
-- reproduces (an automobile factory is a place for reproduction of
   automobiles; just because it's external doesn't mean it's not reproduction.
   Plus, automobiles play a part in maintaining the very economy that makes
   it profitable for automobile factories to work in the first place).
--
"This theory of yours -- that painful memories can be surgically removed..."
"I can't share details...  one of my colleagues might steal my idea."
        --Brenda Starr, 12/25/90

Kenneth Arromdee (UUCP: ....!jhunix!arromdee; BITNET: arromdee@jhuvm;
     INTERNET: arromdee@cs.jhu.edu)

------------------------------

Date: 20 Feb 91 22:43:19 GMT
From: sunc.osc.edu!malgudi!caen!sdd.hp.com!spool.mu.edu!uwm.edu!ux1.cso.uiuc.edu!bradley.bradley.edu!buhub!moonman@tut.cis.ohio-state.edu  (Craig Levin)
Subject: Re: Space Profits

In <9102202032.AA00483@ucbvax.Berkeley.EDU> TPM4017@PANAM.BITNET writes:

>  In particular, I am interested in material manufacturing in space, and
>what might be mined on the moon or Mars.  What types of useful/rare
>materials mightbe/have been found on these worlds, how do we retreive
>them, should we retrieve them, and is it practical to bring them back to
>earth.  Of course there is a whole list of side issues that go along
>with each one of these questions and I think that these are all fodder
>for the discussion.  For the time being, however, I would like to start
>by getting some basic questions answered.  First, what manufacturing
>processes will gain an advantage by being performed in space as oppossed
>to earth-based production?  Second, what resources are known to exist on
>the moon, or Mars, that would have a viable market back on Earth? I am
>looking forward to reading your ideas and opinions.

	Mars has a variety of resources that are similar to those
here, including water, iron, and silicon. However, it would be very
hard to develop these resources in a cost-effective manner, due to the
huge expenditures in fuel to get in & out of the Martian gravity well.
IMHO, I'd prefer Luna. Not only does she have the iron and oxygen that
Mars might, but titanium as well, plus similar metals such as the rare
earths are easier to find there than here. Although you didn't include
them, IMHO the minor planets have the best chance of really turning a
profit if mined properly. As for processes and more information, I
defer to people on the net who have more references/practical
knowledge than I.

Craig\The Moonman\Levin      ***[]***  ///////
moonman@buhub.bradley.edu       )`-----//
The Stars-Our Destination!       ```````

------------------------------

Date: 20 Feb 91 21:52:13 GMT
From: bonnie.concordia.ca!news-server.csri.toronto.edu!utzoo!henry@uunet.uu.net  (Henry Spencer)
Subject: Re: dynasoar

In article <9102140928.AA05393@mozart.unx.sas.com> SNOMCB@mvs.sas.com (Mike Bishop) writes:
> Can anyone tell me what ever became of the Dynasoar project?

Dyna-Soar per se was killed, although low-level work on vaguely similar
things has continued.  Its problem was the lack of a mission, since the
wingless spacecraft had already proved capable of doing almost everything
Dyna-Soar could have done.

> Was this an Air Force endevor?

Yes.

> It seems this was some sort of forerunner of the Shuttle.

Only in a very loose way.  Dyna-Soar would have gone up on top of a Titan;
it had no substantial propulsion system of its own.
-- 
"Read the OSI protocol specifications?  | Henry Spencer @ U of Toronto Zoology
I can't even *lift* them!"              |  henry@zoo.toronto.edu  utzoo!henry

------------------------------

Date: 21 Feb 91 22:07:59 GMT
From: rochester!sol!yamauchi@louie.udel.edu  (Brian Yamauchi)
Subject: Commercially-funded Space Probes (was Re: Space Profits)

In article <21195@crg5.UUCP> szabo@crg5.UUCP (Nick Szabo) writes:

   In article <9102202032.AA00483@ucbvax.Berkeley.EDU> TPM4017@PANAM.BITNET writes:

   >...It seems to me that the ultimate profitability of space will be 
   > determined by what space allows us to produce and carry back to earth. 

   These are very astute observations.  Space industry and settlement
   cannot be undertaken unless it benefits Earth in a large way.  The
   material, energy, and information resources of the solar system have
   the potential to do this.

   >  In particular, I am interested in material manufacturing in space, and
   >what might be mined on the moon or Mars.  What types of useful/rare
   >materials might be/have been found on these worlds,

   Good questions.  So far we haven't found anything like Sutter's Mill,
   but there are many tantalizing areas.  Keep in mind that except for
   the Moon and Mars, the surfaces of our solar system bodies have been
   characterized only crudely if at all.

   The precious metals alone can be worth tens of billions of dollars in the 
   medium-sized (100 m dia) NiFe asteroids.

   Overall, our assay of the solar system to date is poor.  More 
   astronomical observations, meteorite analysis, and planetary exploration
   missions to the Moon, asteroids, Mars, Jovian moons, and comets are needed.

   Nick Szabo			szabo@sequent.com
   Think long-term, act now.

So here's an interesting question, especially for any people who have
had experience dealing with the upper levels of the business sector --
would there be any interest in commercially-funded space probes to
survey resource deposits in the asteroids, comets, Jovian moons, Moon,
Mars, etc?

Many different types of robot probes could fall into this category:
penetrators, rovers, sample return missions, on-site sample analysis
missions, etc.

Part of the question is whether any companies have the foresight to
invest millions now to receive a return of billions in the future.  If
American corporations are too short-sighted, are European and Japanese
companies any better?

The other part is the question of when space law will catch up and
establish guidelines for property rights in space.  There are enough
asteroids and enough open territory on planets and moons that I can't
imagine too many fights over the same resource deposit.  On the other
hand, we need a way for a company to obtain rights to minerals on a
world without being able to claim the entire world (and prevent others
from mining it).

A simple rule for ownership might be based on a minimum amount of
delta-v.  So if someone sent an asteroid into Earth orbit, he could
claim the entire asteroid as his property.  If he just landed on the
asteroid, he could only claim the amount of resources that he could
load onto his ship.

One could also add provisions for ownership of a certain amount of
land area surrounding a permanent base.

Above all, we need to avoid any sort of legislative quagmire like the
late, unlamented UN Moon Treaty.
--
_______________________________________________________________________________

Brian Yamauchi				University of Rochester
yamauchi@cs.rochester.edu		Department of Computer Science
_______________________________________________________________________________

------------------------------

End of SPACE Digest V13 #186
*******************