Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_6/V16NO698.TXT

Internet Message Format | 1993-07-13 | 32KB

Date: Tue,  8 Jun 93 05:10:01
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #698
To: Space Digest Readers
Precedence: bulk


Space Digest                Tue,  8 Jun 93       Volume 16 : Issue 698

Today's Topics:
               1992 NASA Authorization Budget- shuttle
           How would we get back to the moon, if we had to?
              manifest destiny = US getting uppity again
                             mass drivers
                          Moon Base (3 msgs)
                   Moon vs. asteroids, Mars, comets
                        No Planet X? (3 msgs)
          Pres/VP go online with Internet Addresss! (2 msgs)
                    Refs, please (was: Moon Base)
                      relief maps of the world?
                 Why are SSTO up-front costs rising?

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

Date: Mon, 7 Jun 1993 14:49:23 GMT
From: Gary Coffman <ke4zv!gary>
Subject: 1992 NASA Authorization Budget- shuttle
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Paul Dietz) writes:
>In article <[e-mail]> [e-mail] (Matthew DeLuca) writes:
>
>> I am worried about abandoning a whole sector of the aerospace field to
>> another country.  Nixon and the Congress didn't do that.
>
>You mean, like civilian supersonic transports?  What a disaster
>that was -- for the foolish foreigners who kept at it.

Well the Concorde hasn't exactly been a rousing financial success,
but Boeing and Lockheed are still chomping at the bit to produce
a Pacific Rim SST that should be on sounder economic ground. The
Concorde is too small, and has too short a range, to cash in on
the more profitable routes. Environmental concerns may doom the
SST industry, but taking Concorde's lack of financial success
as the bellweather of all SSTs is a bit naive.

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

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

Date: Mon, 7 Jun 1993 15:59:26 GMT
From: Gary Coffman <ke4zv!gary>
Subject: How would we get back to the moon, if we had to?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Phil G. Fraering) writes:
>Anyway, better electronics would be a good improvement on the
>LM's; you wouldn't need two people to land one.

No, just one to look out for rocks.

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

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

Date: 7 Jun 1993 16:37:47 GMT
From: Doug Mohney <[e-mail]>
Subject: manifest destiny = US getting uppity again
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Phil G. Fraering) writes:
>Very well, Henry, you give me no choice. I didn't want to do something
>this destructive, even to save the nation, but your threat of destroying
>the NASM gives me no choice.
>
>Operation Casino Royale Storm has been put on Defcom 5 status. Anything
>remotely suspicious happens, it'll go to 6.
>
>(For those of you who don't know, this is a special sealed railway
>car equipped with slot machines, roulette tables, etc., all designed
>to keep the occupant, Edwin Edwards, occupied while it rolls to
>Quebec, where it shuts down and disgourges its passenger. Then
>the real destruction begins.)

Phil, I dunno.  You could be tried for war crimes.

Far better we take out the ringleaders quietly as an example to the rest of the
Maple Leafs (or is that Leaves?).

The first step will be to disable their computers with the Sherzer Cost
Accounting Methodology Virus, which randomly deflates or inflates numbers based
on the level of "goodness" they are subjectively assigned.

Unfortunately, Spencer might have a counter to this, so we must be prepared to
use the McElwine Cosmo$phere DEATH Ray on Toronto.



    Software engineering? That's like military intelligence, isn't it?
  -- >                  [e-mail]                        < --

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

Date: Mon, 7 Jun 1993 13:01:18 GMT
From: Gary Coffman <ke4zv!gary>
Subject: mass drivers
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Henry Spencer) writes:

>
>At 10G, a mass driver capable of lunar escape velocity is 28km long (14km
>to lunar escape, another 14km to declerate the buckets to rest again).
>But 10G is a ridiculously *low* acceleration, which nobody would use for
>a practical system.  SSI's first prototype mass driver, built out of the
>MIT EE junkbox, demonstrated 30G.  A practical lunar system would almost
>certainly run at 1000G or more, making it only a few hundred meters long.

What you're describing, Henry, is an electromagnetic *cannon*. I had
in mind something with much lower peak energy requirements, more on
the order of a linear induction motor. You could use a 1000 G launcher
for bulk materials, but it'd require very high peak loads on the energy
supply and on the structure, not to mention the buckets. That could
run the cost of building it up more than laying out a longer system
that had to handle lesser loads.

Of course, if you only wanted to launch little pellets, it wouldn't
be much of a problem, but if you wanted fairly hefty chunks, say
for a hypothetical Al-O booster stage, circa 4,000 kg, it'd be absurd.

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

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

Date: Mon, 7 Jun 1993 14:42:08 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Moon Base
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Nick Janow) writes:
>[e-mail] (Gary Coffman) writes:
>
>> (I'm constantly amazed at people's naive faith in directed R&D's ability to
>> solve any problem.)
>
>You seem to be taking the ability to process asteroidal materials in zero-g
>at long communication times on faith.  :)

No, I know that the problems are large for other than water extraction,
but water is the Holy Grail of space processing and it's the easiest of
the materials to get using fairly straightforward fractional distillation
in situ. The long communications times are a major problem that will
slow any other automated processing. Once water is available as reaction
mass, however, larger more competent systems can be sent out for the
other materials at a reasonably low cost. In some cases it may be most
economical to simply bring back chunks for processing closer to home.
Given a good supply of water, space transport becomes easy, if slow,
through use of rather small and simple rocket systems. Since there's
no steep gravitational gradient to fight, high power systems are not
required.

>> Aluminum is not a superconductor at *any* temperature, and hydrogen
>> or helium are both extremely scarce on Luna, so cryogenic refrigeration
>> would be extremely difficult.
>
>That's why I qualified aluminum with "or whatever"; I don't happen to have a
>handy reference of superconductivity handy.  If aluminum won't work, perhaps
>iron, titanium, magnesium, calcium, sodium or some other easily-processed
>metal will work.  It may not even necessary to use superconductors.

To handle the necessary high power for a mass driver of the size you'll
need, superconductors would be very important. They aren't absolutely
necessary, but without them the system would have to be substantially
larger, consume substantially more power, and require a large amount
of conventional cooling.

>> The hundreds of billions would not be for the construction of the mass
>> driver anyway, they'd be for the massive infrastructure that would have to
>> be developed on the Moon to achieve the capability to *build* a lunar mass
>> driver. The thing would need to be on the scale of the SSC stretched out in
>> a straight line and massively enlarged to accelerate something larger than
>> subatomic particles. The skilled labor, the tools, and much of the
>> materials would have to be imported from a quarter million miles away via
>> two costly gravity wells, and maintained on Luna for a period of years.
>
>You're using present techniques designed for Earth and trying to apply them
>directly to the moon, while using vapourware techniques as an argument for
>asteroidal mining.  Remote operation and automation techniques would apply to
>both projects, to reduce costs.  Furthermore, if you apply the porkbarrelling
>costs of the SSC to the mass driver, it's only fair to apply it equally to
>asteroid mining...

I'm assuming the laws of physics are the same on Luna as Earth. It's
fairly straightforward to calculate size, power requirements, and structural
strength requirements for mass drivers wherever they are built. If we
limit ourselves to BB size payloads, a mass driver can be small and
cheap, but if you need to launch larger things, size and cost scale
up rapidly. Comet processing equipment is conceptually "vapourware"
of the same type as used in any distilling house. This isn't exotic
technology; it's backyard technology. Find a chunk of frozen muck,
put an oven bag around it, and shine a focusing mirror on it. Viola,
water condenses on the cool surface of the bag. This is a standard
survival trick taught to airmen and solders. Naturally it's a bit
more complex in space due to the lack of gravity gradient, but it's
also simpler due to the vacuum present at startup. All the vapor
pressure is the result of vaporizing your target material, you control
temperature so only one material volatilizes at a time, and natural
diffusion will lead molecules to the cold trap, created by a simple
sun shade, to be condensed. The only tricky part is getting the
condensed material out of the cold trap. If the trap is spun, that
should allow the liquid to be extracted in a way similar to the spin
cycle on a washing machine.  This neatly bypasses the need to deal
with pumping mud.

>> Al-O hybrid rockets might work, but the exhaust product, aluminum oxide,
>> is a solid used on Earth as an abrasive. This isn't reusable rocket
>> technology. We're talking expensive expendibles with necessarily short
>> firing times.
>
>Hybrid?  Both the aluminum and oxygen would be liquid (vacuum is great for
>keeping hot things hot and cold things cold).  Erosion of the nozzles might
>be handled by venting the excess oxygen as a boundary layer to protect the
>surfaces.  Alternatively, you can just make them easily changed and recycled.

I would suggest it's not so easy to keep aluminum liquid in valves and
piping where radiation losses are highest due to unfavorable surface/volume
ratios. It would seem more practical to use the aluminum as a cast
cylinder, likely blow casting to give a higher surface area, with a
central hole where oxygen is fed. That is a hybrid, and it can be
throttled, though response is non-linear. The nozzles would likely have
to be changed after every flight, and they require machining to make
from a high temperature alloy with good abrasion resistance. Actually,
a cast ceramic nozzle design might be best. Precision casting facilities
would need to be developed on Luna, but that's easier than the basic
aluminum refinery, which would likely use varients of the Bayer and
Hall processes. That requires caustic soda, sodium aluminum fluoride,
and carbon lined pots drawing massive amounts of electricity. Looks
like you'll need a large solar cell manufacturing plant too.

>> Recovering volatiles doesn't require scooping. It just requires heating in
>> situ and capturing the boil off. We're talking plastic bags and mirrors
>> here. Processing metals and other solids will be more challenging, but just
>> boiling water is not beyond the state of the art.
>
>All right, that sounds reasonable.  It would fit in with Paul's vision of
>Earth-launched metals and other non-volatiles supplying small scale LEO
>industrial activity.  However, in that scenario, it will probably be quite a
>while until there's a serious market for large quantities of mass, and by
>then the desired material could be aluminum and oxygen, and be cheaper to
>process from lunar dust than asteroidal rock.  It could be nickel-iron and
>methane; we just can't predict it at this time.

Oxygen is cheapest from water, given plenty of water and sunshine.
Aluminum may or may not be a structural metal of choice. Low mass is
not as significant in space as it is when fighting a gravity well to
get it to orbit, and iron is easier to work and has superior properties
for most uses.

>> All lunar landings will have to be under rocket power with near vertical
>> descents on courses well away from critical lunar infrastructure. That's
>> going to require massive amounts of volatiles for fuel. Getting them from
>> space is the only economically sound course.
>
>The mass driver launches Al-O modules up, for bringing supplies down.  It
>even dumps lots of aluminum oxide dust at the landing site, which can be
>swept up and recycled.  :)

See comments on the required size of a mass driver capable of launching
large Al-O stages.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

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

Date: Mon, 7 Jun 1993 15:06:31 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Moon Base
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Phil G. Fraering) writes:
>Oops, I forgot something in the last post:
>
>About the assumption in the preprint about the "mainly water"
>bit... part of the reason I wanted a reference was to see if
>anyone had worked out a good filtration system or pump... or
>separation system, for that matter.
>
>How scalable would _those_ be?

Well if you look at the idea I proposed, filtration shouldn't be
an issue, and spinning the cold trap recovers the liquid. Separation
is handled by temperature control. You abandon any muck that remains,
along with the baggie. The system should be as scalable as the bags
and mirrors. Both are thin plastics, one aluminized. The devil is
in the details of course, but there don't appear to be any major
showstoppers.

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

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

Date: Mon, 7 Jun 1993 15:40:32 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Moon Base
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Nick Janow) writes:
>[e-mail] (Jim Hart) writes:
>
>> Do you know what the hell you are talking about?  No one has built factory
>> machinery that recycles water and air like that, not to mention all the
>> gooey crap machines use that is missing from the moon. Not even close.  Air
>> pollution and wastewater are produced in huge volumes by just about any
>> industry worthy of that title.
>
>As Gary did, you are making the mistake of assuming that present "designed
>for Earth today" processes will be used directly in space.  No one has built
>(that I know of) a factory that recycles volatiles as much as possible,
>because that would be a bad economic decision.  Why spend a million dollars a
>year extra in recycling water when your competitor spends only ten thousand a
>year on large volumes of water which is used and dumped?  Industries dump
>huge volumes of fluids and gasses because they haven't been charged for the
>environmental costs of it.

You said it. "No one has built a factory that recycles volatiles as much
as possible, because that would be a *bad* economic decision." IE it
costs too much. Lunar materials will already cost too much because of
the extreme steps needed to get them. Increasing the cost of processing
even more simply makes them more uneconomic.

I think it's fairly safe to say that extraction industries generally
use the cheapest possible methods unless forced to use less economic
methods by regulation. The cost differential between pass through
and total recycle for many industries, such as extraction and primary
refining, can amount to thousands of percent differential in costs.
In other industries, mostly fabrication, the cost difference can be
minimal. Look to oil shale extraction to see where the presence or
absence of cheap water can make or break the industry.

>No one has developed the technology to refine aluminum with a closed-cycle
>for volatiles because there's been no economic motivation to do so.  That
>doesn't mean it's not possible.

Hall process aluminum refining doesn't require large amounts of volatiles,
except in the preliminary Bayer process to turn the ore into alumina for
the pot line. That water could well be recycled, though disposing of the
"red mud" would be tricky if you can't flush it. The cryolite, and the
enormous amount of electricity needed are the real show stoppers. You're
going to need really huge fields of solar cells, or really big solar
thermal electric plants to run the pot line. And shutting down or starting
a pot line is a serious time consuming chore, usually requiring a week or
more. That two weeks a month interuption in power is going to be the real
killer. There are other table top processes for refining aluminum, but
none are cost effective, resulting in pure aluminum that costs more per
ounce than gold.

>What is "all the gooey crap machines use"?  Do you mean lubricants for
>bearings, which can be replaced by magnetic bearings?  Do you mean cutting

Magnetic bearings? In ore crushers and earthmovers? Surely you jest.
They're fine for tiny precision reaction wheels and the like, but not
for the heavy erratic loads presented by working machinery. Bearing
lubricants aren't a killer, just another nagging expensive detail.

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

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

Date: Mon, 7 Jun 1993 15:54:08 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Moon vs. asteroids, Mars, comets
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Nick Janow) writes:
>[e-mail] (Jim Hart) writes:
>
>> Furthermore, most of the mass of processing materials used to make those
>> robots are volatiles,...
>
>...assuming a "designed for Tokyo 1992" robot factory, building robots
>designed for Earth.
>
>You do not need to use today's factories' techniques on the moon.  The
>working environment is different, and makes different techniques possible and
>economical, and makes today's techniques uneconomical.  Instead of machining
>a gear out of metal using lots of cutting fluid, you can use the
>laser-sintering fabrication technique that is now being developed for
>"desktop fabrication". Instead of washing parts every few steps in
>production, you can take advantage of the moon's clean vacuum.  If hydraulic
>fluids are uneconomical for moving arms, use electric motors.

The only significant difference in the working environment on Luna
is the presence of hard vacuum, usually a hinderance because of
unwanted vacuum welding, lack of heat transfer, and undesired
volatilization of working materials. The lesser G isn't really a
factor in most industrial processes, it's still high enough to
prevent exotic separation techniques.

The reason laser-sintered fabrication is restricted to the desktop
is that it's too damn expensive to use in production volume. And,
someone has to have a factory to produce the, usually exotic, metal
powders used in the process. The technique is also only suitable for
a small range of applications. You still need to turn or grind if you
need a fine finish, such as for bearings and shafts. The Moon's "clean
vacuum" won't remove the grit of grinding, or the fine chips from
machining, or the residues from chemical processing. Since hydraulic
systems are usually nominally closed, they aren't great consumers of
volatiles, and they have advantages over electric motors in many
applications.

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

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

Date: 7 Jun 93 17:19:52 GMT
From: [e-mail]
Subject: No Planet X?
Newsgroups: sci.space,sci.astro,alt.sci.planetary

I read this paper with real enthusiasm.  It is an excellent example in
Astronomy where precise data kills speculation (although I suspect that
many will go on believing in Planet 10 (when are we going? - "Real Soon Now")
and simply ignore this great new data) and closes the case.

My question:  These new precise measurements (afterall 0.5% error in
Mass of Neptune is still a lot of grams!) must ultimately affect chaos
theory.  I wonder if it changes the exponent in these models which
integrate all the orbits up a million or so years into the future!

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

Date: 7 Jun 1993 10:53 PST
From: SCOTT I CHASE <[e-mail]>
Subject: No Planet X?
Newsgroups: sci.space,sci.astro,alt.sci.planetary

In article <1uvtbo$[e-mail]>, Dr._DarkMatter writes...
>I read this paper with real enthusiasm.  It is an excellent example in
>Astronomy where precise data kills speculation (although I suspect that
>many will go on believing in Planet 10 (when are we going? - "Real Soon Now")
>and simply ignore this great new data) and closes the case.

Don't forget - no matter where you are going... when you get there... there
you are.  (Or something like that.  It's been at least seven years since
the last time I saw that movie.)

Seriously, I have not read the paper, but nevertheless, have gotten a rather
different impression from the reviews I have read.  It's not so much that
"precise data" have killed speculation.  Rather, it's a matter, at least
in part, of "careful analysis" demonstrating that the data are too imprecise
to reveal any supposed discrepancy.

In particular, the obital parameters of Neptune are "poorly" known.  It
has not completed even a single orbit since its discovery, so that's
not too surprising.  This and other uncertainties make it impossible
to assign the inconsistencies in the data to an actual 10th planet rather
than plain old measurement error and uncertainty.

-Scott
--------------------                          New .sig under construction
Scott I. Chase                                     Please be patient
[e-mail]                                   Thank you

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

Date: 7 Jun 1993 18:11 UT
From: Ron Baalke <[e-mail]>
Subject: No Planet X?
Newsgroups: sci.space,sci.astro,alt.sci.planetary

In article <1uvtbo$[e-mail]>, Dr._DarkMatter writes...
>I read this paper with real enthusiasm.  It is an excellent example in
>Astronomy where precise data kills speculation (although I suspect that
>many will go on believing in Planet 10 (when are we going? - "Real Soon Now")
>and simply ignore this great new data) and closes the case.
>

Bear in mind that this study only indicates that there is no *large*
planet left undiscovered.  It does not eliminate any Pluto-sized planet.
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | [e-mail]
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | The tuatara, a lizard-like
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | reptile from New Zealand,
|_____|/  |_|/       |_____|/                     | has three eyes.

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

Date: 7 Jun 1993 15:53:08 GMT
From: Doug Mohney <[e-mail]>
Subject: Pres/VP go online with Internet Addresss!
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Steinn Sigurdsson) writes:
>In article <[e-mail]> [e-mail] (Doug Mohney) writes:
>Sorry. Not this time...
>
>   *shudder*  Earliest The O-zone man could get elected would be 2000, which is
>
OK, I was thinking in terms of ELECTION YEARS.  So, ok, ya got me there, Siggy.
>
>   Assuming no tragic thing happens to the current occupant of the White House, in
>   which case he could be sitting in the Oval Office sooner.
>
>Not even that. Clinton might just decide he's had enough of all the
>shit he's taking.
>
>   I don't know where you get the perception Al Gore is a "good bet" to become
>   president... long-distance predictions of that sort are highly risky.
>
>Well, Bush set a good precedent,

Bush rode in on the coat tails of a successful president.

> and before him Johnson, not to mention Truman...

Who both got into office (we're talking ELECTION) because their Presidents
died.

OK, lookie, I'll get out the voodoo doll and spell it out for you:

    A) If Clinton is successful, or thinks he can be successful,
       he'll run again in 1996.

    B) If Clinton fails, it is unlikely his Veep will be able to
       clean himself of the stench.  It would leave Gore out of 1996.

Most "failed" presidents (i.e. those who don't get re-elected; Carter, Bush)
run again regardless of their track record.  It is highly unlikely Clinton
would sit out '96 and let Gore run, less so that Gore would be able to run on
his "merits" as Veep.

And in recent times, old Fritz Mondale got TROUNCED for being associated
with Carter (not to mention having less charisma than Gore :-)

>Yahboo, you guys are just sore cause you lost the War of 1812
>and had to repaint the White House ;-)

Rematch anytime, anywhere.



    Software engineering? That's like military intelligence, isn't it?
  -- >                  [e-mail]                        < --

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

Date: Mon, 7 Jun 1993 17:48:23 GMT
From: Rob Healey <[e-mail]>
Subject: Pres/VP go online with Internet Addresss!
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Gary Coffman) writes:
|> In article <[e-mail]> [e-mail] (Henry Spencer) writes:
|> >
|> >If you must write to someone, try writing (on paper) to the vice-president.
|> >He is a good bet to be president within ten or fifteen years, and he does
|> >not get much mail.
|>
|> Al Gore president? If true it signals the end of the Republic.
|>
    If true it would be no worse than Dan "We can breath on Mars" Quale... B^)

        -Rob

#include <std/disclaimers.h>

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

Date: Mon, 7 Jun 1993 15:00:43 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Refs, please (was: Moon Base)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Phil G. Fraering) writes:
>[e-mail] (Gary Coffman) writes:
>
>>That's why water from comets is so attractive. Extraction is simple,
>>and can scale from small to large by bootstrapping.
>
>This reminds me... I'd like to find a list of references to the
>extraction technology involved. (I have references on most everything
>else).

Check with Jack Daniels. :-)

The idea is to use solar driven fractional distillation. For a practical
example, put a chunk of moist earth in a oven bag and set it in the
sun. The surface quickly becomes covered with pure condensed water.
In space you need to arrange a shaded cold trap, a focusing mirror,
finer temperature control due to the various volatiles present, and
a liquid extraction method (spinning the cold trap should do), but
the principle is the same. When you're done, you have a muddy plastic
bag that you can leave for later, more advanced, missions to recover
and recycle.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

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

Date: 7 Jun 93 16:40:35 GMT
From: John W Connelly <[e-mail]>
Subject: relief maps of the world?
Newsgroups: sci.space

Can anyone give me a pointer to where I might find a relief map of the world
in GIF or some other computer-displayable form?  What I'm looking for is a
graphic showing the mountain ranges on each continent.

Any help would be much appreciated.  Please reply directly to this account.

Thanks in advance!
--John C.

--
/===========================================================================\
| John W. Connelly | "If you choose not to decide,  |   [e-mail]    |
| Cognitive Psych. |   you still have made a choice"|+=+=+=+=+=+=+=+=+=+=+=+|
| U. of Pittsburgh |                - Neil Peart    | [e-mail] |

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

Date: Mon, 7 Jun 1993 16:18:22 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Why are SSTO up-front costs rising?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>finally, these numbers are costs and not prices. What price is charged
>will depend on the market and I don't want to speculate on that just yet.
>They would price it so it is just a bit cheaper than ELV's and make a ton
>of short term $$ or they cold price it to build the market and make more
>over the long run.

Bet they take the former option if the program works. Otherwise they'll
risk losing out to competitors for the excess business after their window
of exclusivity closes.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

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End of Space Digest Volume 16 : Issue 698
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