Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT_ZIP/spacedig/V15_1/V15NO109.ZIP/V15NO109

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Date: Fri, 14 Aug 92 05:04:26
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #109
To: Space Digest Readers
Precedence: bulk


Space Digest                Fri, 14 Aug 92       Volume 15 : Issue 109

Today's Topics:
         Beanstalks in Nevada Sky (was Re: Tethers) (3 msgs)
                Energiya's role in Space Station assem
                      He3 Power Source (2 msgs)
                          Parsecs? (2 msgs)
                        Private space ventures
             Random Notes (Was Re: NASP, NLS, SSTO, etc.)
                   Seeding Mars with life (3 msgs)
                         Solar System Journal
             SPS feasibility and other space development
    Two questions about the shuttle tethered satellite experiment

    Welcome to the Space Digest!!  Please send your messages to
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----------------------------------------------------------------------

Date: 13 Aug 92 23:22:41 GMT
From: Hans Moravec <[e-mail]>
Subject: Beanstalks in Nevada Sky (was Re: Tethers)
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Dave Jones) writes:
|> >
|> I don't remember diamond featuring as tether material.  However, since
|> it is (theoretically) a single-molecule solid, the answer is
|> (theoretically) yes.  What weakens diamond (and metals, other crystals
|> etc.) is the existence of defects in the structure, where the regular
|> patterns of interatomic bonds are disrupted.  These defects act as
|> focus points for stress, and propagate themselves under that stress,
|> so most crystalline materials are much much (I forget how many orders
|> of magnitude) weaker than you'd expect if you did a theoretical
|> calculation based on the strengths of the bonds.

Thin fibers have lower probability of defects, so get stronger
per cross section as they get thinner (also more flexible).

Graphite fibers are stronger than diamond in 2 directions
(two out of three ain't bad!)
Graphite fibers with over 50% of the theoretical strength
have been grown several millimeters in length.  (Plenty
strong for Earth skyhooks, but not enough of them).

The latest and greatest version of carbon fiber is Buckytubes!
Like graphite but rolled up forming a teeny, tiny soda straw.
No loose edges or ends (the ends are capped with a half Buckyball).
I've read lengths of about a centimeter have been produced,
grown on a charged sphere (radiating out like hair on a van de Graf
generator, only much, much thinner)

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

Date: Thu, 13 Aug 92 19:01:23 PDT
From: [e-mail]
Subject: Beanstalks in Nevada Sky (was Re: Tethers)
Newsgroups: sci.space

"I don't see much point in it, though. And why Nevada? Is it some
intricate scheme to get around the state and county laws regarding
gambling and such? :-)"

Yes, air space over a state is controlled by the laws in that state.
I assume this will eventually happen with the space near the Earth
over the state as well.  Therefore I want to build a casino over
Nevada, with no tethers passing over the airspace over any other
states and/or countries.  My question is how much thrust would I
need to do this?

"I don't remember diamond featuring as tether material.  However, since
it is (theoretically) a single-molecule solid, the answer is
(theoretically) yes."

How strong could a perfectly made diamond tether be?  Could it support
an elevator?  Anything heavier?  How long could it get?

                                                             Eric Klien.

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

Date: Fri, 14 Aug 1992 06:34:18 GMT
From: Christopher Neufeld <[e-mail]>
Subject: Beanstalks in Nevada Sky (was Re: Tethers)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Thomas J. Nugent) writes:
>[e-mail] (Dave Jones) writes:
>
>>Clarke also had his tower made of that famous variety of unobtainium,
>>monomolecular filament.  Assuming he'd done some basic estimates, you
>>have to figure that's the kind of tensile strength you need for a cable
>>23,000 miles long.  He also had a captured asteroid stuck out on the
>>far end as a counter-weight, possibly at a height beyond GEO.
>                              ^^^^^^^^
>Most definitely beyond GEO - the Center of mass needs to be at GEO for
>the whole thing to stay above one spot.  i.e.,therefore,ergo: the cable
>must go (pretty far) beyong GEO.
>
   This is going to sound like a picky objection, but it isn't actually
the centre of mass which must be at GEO. That would be true for a
balanced tether in an environment where the force on an element of the
tether is +K outward from GEO and -K inward from it.
   The calculation actually gets a bit complicated. A balanced tether
which is not terminated with a big rock (ie. maintains its taper on the
outward arm for as far as it takes to reach the balance condition) will
turn out to be about six times as long, if memory serves, as the distance
to GEO. This puts the centre of mass a long way out.
   What you really want is that the net force on the tether in the
noninertial frame of the rotating Earth be zero. Assuming the tether
supports tensile loads but not compressive loads you can put a heavier
weight on the end than necessary and let the extra force be taken by the
anchor to the ground. In principle, given a big enough weight the anchor
can be arbitrarily close to GEO as long as it is outward from it.

>Tom Nugent        e-mail: [e-mail]


--
 Christopher Neufeld....Just a graduate student  | Confidence is the feeling
 [e-mail]    Ad astra  | you have before you
 utzoo.utoronto.ca!generic!cneufeld              | understand the situation.
 "Don't edit reality for the sake of simplicity" |

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

Date: 13 Aug 92 22:59:03 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Energiya's role in Space Station assem
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>In article <[e-mail]> [e-mail] writes:
>
>>With the current budget situtation, it is extremely difficult to fund long-lead
>>items. As noted, NASA does not operate under a multi-year budget.
>
>The DoD is constitutionally forbiden to run under allocations lasing more
>than two years and they rarely get them. Yet they build $100 billion
>aircraft carriers and other hardware.

Yes, and the cost overruns are truly horrendous. Political procurements,
and all single customer government procurements are political, rarely
ever come in on budget or on time. In fact, contract "adjustments" on
a year to year basis are SOP. Without them, most military contractors
would quit the business. Name *one* major military procurement that
proceeded on a fixed price basis with *no* adjustments. Congress is
notorious for "stretching out" procurement in a way that saves money
this year, but adds horrible extra costs in the "out years" if the
full procurement ever is actually filled. Recent examples include B1B,
B2, and Seawolf. ATF is travelling down the same road.

[deleted]
>No I didn't and I have already pointed this out to you. The new components
>are commercial procurements. They will be developed and operated by the
>private sector who will put its own capital at risk. This means that NO
>government money is expended until services are provided. Shuttle will
>continue to operate with the same funds it uses now until the cheaper
>replacement comes on line.

NASA can't legally sign a binding procurement contract that promises to
buy X launches for Y dollars from Z corporation over multi-year periods.
And there is *no* other market for these Shuttle replacements. The
"out years" are total speculation. If your plan is sound, then show
us that the manufacturers have built the systems on *speculation*
with no assurance whatsoever that they will be purchased, because
that's the way it actually works. If you can show that, then your
plan deserves consideration. Otherwise, it has about as much reality
as a Star Trek episode.

The Rockwell Shuttle has the great advantage that it is *operational*
today. Construction costs are already sunk and can't be stretched or
killed by Congress. Only operational costs are ongoing. Expendibles
must include construction costs for *each* flight and that's highly
dependant on the *rate* of production. Since Congress can slow or
speed that rate at will, no firm numbers can be predicted with any
degree of certainty.

Gary

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

Date: Thu, 13 Aug 1992 20:52:49 GMT
From: Richard Martin <[e-mail]>
Subject: He3 Power Source
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (thomas.vandoren) writes:
>Subject: He3 Power Source
>Distribution: world
>Organization: AT&T
>   About 2 weeks ago I saw a series of 5 minute modern videos of great interest.
>One of them was about a proposal to use Helium3 mined from the moon as a power
>source on Earth.  One of the claims was that the value of one shuttle load
>of He3 was a couple billion dollars or something in that order when computed
>relative to the power output it would provide.
Maybe, but shuttles don't go to the moon, and even if they did, there's nowhere
for them to land.
>   Does anyone have more info, opinions on that proposal?  If it is true it
>would seem that there may be some kind of business case for lunar operations.
>My only concern or potential skepticism is how easy is it to develop an
>He3 power plant?  I mean are we talking something as hypothetical as fusion
>power, or something that does have a reasonable chance of being developed
>in the near future.
Last time I looked, He3 was only really significant in fusion power.
>   The video mentioned how He3 as exhaust from the sun doesnt make it to the
>Earth's surface due to the atmosphere or magnetosphere but does get absorbed
>into the lunar soil.  It showed proposed lunar surface strip mining machines
>that would filter out the He3 and replace the regolith behind it thus having
>minimal environmental impact.
         ^^^^^^^^^^^^^
I get a big kick out of this term being used to describe the moon.  It's a rock.
There is no environment.  Well, sorry, there is.  But not in the sense which
has been used down here--you don't have to worry about ecology (there is none)
nor about noise pollution (none of that, either).  Mining could make a pretty
bad mess of the place, but I don't know what proportion of the worry is simply
aesthetic.
>Other items such as oxygen and water could be
>extracted at that time as well.
Solar panels and batteries can supply water for the moon--I'd concentrate on
getting the O2 and H2O, before mucking about with stuff which is apparently
just as rare, but not necessary to life.
>  How hypothetical is this and is it practical?
>
>Lee
>
I don't really know, but it was fun heckling you.  No.  Any excuse to go to
the moon is good enough for me, actually.  Just think--if we can get He3 out
of the regolith, we've got it in situ, and we can build _massive_ tokamaks
up there.  (Sink it in the rock, power it with solar, and don't worry, the
nearest population centre is a good few light-seconds away--heck, if you can
figure out a way of harnessing the power of explosions, you could do it there!)

Oh dear, it makes me think of the _Usbourne Book of the Future_ I was given
several years ago.  Copyright 1979.  When I read it, I don't know whether to
laugh or cry.

Seriously, though...
no offence meant, and I'm getting a little tired about reading about ACRVs.
Richard. =)
--
--------------------------------------------------------------
Richard Martin                   [e-mail]
CARP Systems International    "Don't Panic!  Things are
Kanata, Ontario, CANADA        about to get much worse!"

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

Date: 13 Aug 92 22:03:50 GMT
From: "Frederick A. Ringwald" <[e-mail]>
Subject: He3 Power Source
Newsgroups: sci.space

In article <[e-mail]>
[e-mail] (thomas.vandoren) writes:

> My only concern or potential skepticism is how easy is it to develop an
> He3 power plant?  I mean are we talking something as hypothetical as fusion
> power

It *is* fusion power, and of an advanced kind, at that.

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

Date: 13 Aug 92 23:13:00 GMT
From: "RING, DAVID WAYNE" <[e-mail]>
Subject: Parsecs?
Newsgroups: sci.space,sci.physics

[e-mail] (Mcirvin) writes...
>It's not the Earth-Sun distance, it's the distance from which the
>Earth-Sun distance subtends an angle of one second of arc.  That's
>*not* a coincidence; it follows from the definition.

>If I've gotten anything wrong, please correct me...


Forgive me if I'm being stupid, but isn't everybody ignoring a factor of 2
somewhere?

Dave Ring
[e-mail]

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

Date: 14 Aug 92 01:26:18 GMT
From: Mcirvin <[e-mail]>
Subject: Parsecs?
Newsgroups: sci.space,sci.physics

[e-mail] (RING, DAVID WAYNE) writes:

>[e-mail] (Mcirvin) writes...
>>If I've gotten anything wrong, please correct me...

>Forgive me if I'm being stupid, but isn't everybody ignoring a factor of 2
>somewhere?

Good question, but the answer is no.  Everyone so far who's given
even remotely the right definition has gotten the factor of 2 right.
The parallax of a star is the semimajor axis of the ellipse its
image performs in the sky, and correspondingly it's the AU, not the
width of the Earth's orbit, that subtends a second of arc.
*That* I do remember.  Think of the parallax as the amplitude of
a yearly apparent oscillation.

Let's check the calculation, in fact.  There are 1.296E6 arc-seconds
in a circle, or about 2.06E5 in a radian.  So 2.06E5 times the AU
(1.5E11 m) should be the parsec.  That comes to 3.1E16 m, which is
about right, since the light-year is about 1E16m.  So we definitely
have the right factor of 2 here, at least.  Rounding and probably
arithmetic errors are undoubtedly rampant in the above, since I did
it by hand.

--
Matt McIrvin, professional gradgrind, amateur Usenet drifter

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

Date: Fri, 14 Aug 92 06:38:42 GMT
From: dann cutter <[e-mail]>
Subject: Private space ventures
Newsgroups: sci.space

Could anybody out there please tell me the current status of the private
space industry world wide. What comapnies exist... what they have done...
thanks

_______________________________________________________________
Dann Cutter  Stellar Enterprises /
[e-mail]

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

Date: 14 Aug 92 00:57:11 GMT
From: Gary Cooper <[e-mail]>
Subject: Random Notes (Was Re: NASP, NLS, SSTO, etc.)
Newsgroups: sci.space

In <[e-mail]> [e-mail] writes:

>> at Mississippi State University for NASA and the NASP JPO.  It should
>  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
This isn't the same mock-up that was at the '89 Paris Air show, was it?
I'm pretty sure that was made at VA Tech.
--
Gary Cooper (not the dead one)    personal responses - [e-mail]
* * * * * * *  Standard Disclaimers Apply, Of Course * * * * * * * * *
      "The Vice-Presidency is not worth a pitcher of warm spit."
            - Vice-President John Nance Garner -

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

Date: Fri, 14 Aug 1992 01:54:12 GMT
From: David Knapp <[e-mail]>
Subject: Seeding Mars with life
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (John Roberts) writes:
>
>-From: [e-mail] (David Knapp)
>-Subject: Re: Seeding Mars with life
>-Date: 11 Aug 92 15:38:58 GMT
>-Organization: University of Colorado, Boulder
>
>-In article <[e-mail]> [e-mail] writes:
>->Even the "vent" organisms are exploiting the chemical gradient set up
>->by photosynthesis (they oxidize the reduced chemicals coming out of the
>->vents), and are therefore not completely geothermally powered.
>
>-The do not comsume photosythesized materials. (at least according to National
>-Geographic...)
>
>I think the point Paul's trying to make is that the organisms take advantage
>of oxidizing chemicals (perhaps oxygen among them) produced by photosynthetic
>life. I don't know enough on the subject to confirm or deny that. I have
>read that some bacteria get their energy by some chemical change in iron
>compounds, and that others get it by converting one sulfur compound to another,
>and it would be helpful if Paul would comment on whether both of these are
>tied in with compounds produced by photosynthesis.

You say *the* organisms. Perhaps you mean most Earth organisms? I agree. Do
we know that there *isn't* any life for sure on Mars? No. If there were some
type of bacterial or fungal (or new class) of life there, do we know what
effects Earth life would have on it? No, we cannot know that.  Are we
certain that no life form from Earth could survive *anywhere* on Mars? No,
of course not. We don't even know what 'most' of Mars is even like. With
so many questions unanswered, don't you think it is prudent to proceed with
the utmost caution?


>
>-If we get cocky and think we can forcast everything that might ever happen
>-concerning life on another planet or moon, we could quite easily destroy our
>-ability to detect it or study it.  You might not think that would be a waste,
>-but luckily, NASA and ESA (and many others) do. For the cost of creating a
>-sterilization policy, we insure a better possiblity of finding life if it
>-exists on Mars.  We've already mucked up this planet enough with ego-
>-centricity, I don't think it's a bad thing at *all* to treat the only other
>-planet in our solar system, which might be able to support humans, with kid
>-gloves.
>
>If there were some cheap and easy way to get humans to Mars in the near
>future, I'd say we should forget about Mars contamination issues, and go
>for it. However, that does not appear to be the case, so an argument can
>be made in favor of playing it safe with unmanned spacecraft.
>

Depending on what you call 'near future', I agree. But we can also do *that*
with a high degree of decontamination so our studies while we're there are not
possibly hindered by Earth organisms.

We have *much* ground work to do with unmanned craft before that could happen
anyway.



--
David Knapp                                      University of Colorado, Boulder
Highly Opinionated, Aging  and                      [e-mail]
Perpetual Student of Chemistry and Physics.
            Write me for an argument on your favorite subject.

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

Date: Fri, 14 Aug 1992 01:55:50 GMT
From: David Knapp <[e-mail]>
Subject: Seeding Mars with life
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Richard Martin) writes:
>In article <[e-mail]> [e-mail] (John Roberts) writes:
>>
>>-From: [e-mail] (David Knapp)
>>-Subject: Re: Seeding Mars with life
>>-Date: 11 Aug 92 15:38:58 GMT
>>-Organization: University of Colorado, Boulder
>>-In article <[e-mail]> [e-mail] writes:
>>->Even the "vent" organisms are exploiting the chemical gradient set up
>>->by photosynthesis (they oxidize the reduced chemicals coming out of the
>>->vents), and are therefore not completely geothermally powered.
>>
>>-The do not comsume photosythesized materials. (at least according to National
>>-Geographic...)
>>
>>I think the point Paul's trying to make is that the organisms take advantage
>>of oxidizing chemicals (perhaps oxygen among them) produced by photosynthetic
>>life. I don't know enough on the subject to confirm or deny that. I have
>>read that some bacteria get their energy by some chemical change in iron
>>compounds, and that others get it by converting one sulfur compound to another,
>>and it would be helpful if Paul would comment on whether both of these are
>>tied in with compounds produced by photosynthesis.
>>John Roberts
>>[e-mail]
>Please forgive me if I make any glaring errors, but I have read about a type
>of bacteria which carries out anaerobic respiration.


Would that be botulism?




--
David Knapp                                      University of Colorado, Boulder
Highly Opinionated, Aging  and                      [e-mail]
Perpetual Student of Chemistry and Physics.
            Write me for an argument on your favorite subject.

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

Date: 14 Aug 92 02:06:32 GMT
From: David Knapp <[e-mail]>
Subject: Seeding Mars with life
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Paul Dietz) writes:
>In article <[e-mail]>, [e-mail] (David Knapp) writes:
>
>|> >|> You don't know that, and, in fact, nobody else does either. There is
>|> >|> strong evidence that there exists abundant water supplies within the
>|> >|> Martian regolith.
>|> >
>|> >There exists abundant water of hydration, and ice, probably.  But *not*
>|> >liquid water anywhere near the surface.  The pressure is simply too low.
>|>
>|> I contend that the subsurface of Mars is as much on Mars as the surface is
>|> and that if water exists there in liquid form, then liquid water exists on
>|> Mars, which you said was impossible.
>
>Oh, good grief.  I said "on Mars".  Not "in Mars".

Which, as far as life is concerned, doesn't make a lot of difference.

>|> >Life exists at depth on earth only because it also exists at the surface.
>|>
>|> I think you've suggested a cause an effect that most biologists would
>|> disagree with.
>
>Name one?

I will ask if I can use his name.

>
>|> >Soil organisms decompose organic compounds produced by photosynthesis.
>|>
>|> Photosynthesis isn't required for all life. Not all life forms consume
>|> products of photosynthesis. Deep ocean vent tube worms are one example.
>|>
>|> >Deep organisms that eat oil run on fossil photosynthetic energy.
>|> >Even the "vent" organisms are exploiting the chemical gradient set up
>|> >by photosynthesis (they oxidize the reduced chemicals coming out of the
>|> >vents), and are therefore not completely geothermally powered.
>|>
>|> The do not comsume photosythesized materials. (at least according to National
>|> Geographic...)
>
>
>Perhaps you had better get your biological information from
>a different source, then.  Oxygen is a photosynthesized material,
>you know.

This doesn't mean there cannot be life using other means of respiration. And
even if all possible lifeforms in the universe just happened to respirate
oxygen (which I wouldn't assume) there may be resorvoirs of oxygen large
enough to supply a small population of organisms with respiratory material.
Or, there may be other reducing mechanisms *within* the lifeform.

You forget we're talking about life on Mars, not life on Earth. Life on Mars
is about as absurd as putting a man on the moon. The only reason we might
think it's a silly thought is because we haven't seen it yet.

> If all photosynthesizing organisms on Earth were
>to be killed, the tube worms would die out when the
>atmosphere's oxygen was depleted (which would take a few million years)
>or when the oceans became anoxic.

And why do we need photosynthetic material to produce the free oxygen? Only
because there are mechanisms on Earth which would otherwise take up all the
oxygen and we'd be left with a lot of oxidized materials. That is correct,
as far as we know, *here*. Not everywhere. And we haven't even found or
classified all life *here* yet.

Do you know of all the oxygen processes occurring everywhere on Mars? This is
the point. You are arguing from a lack of knowledge of the Martian surface,
subsurface, atmosphere etc. In fact, we all do. We know very little about
Mars when it comes down to it. Which is why I assert we should take all
precautions to influence it as little as possible.


--
David Knapp                                      University of Colorado, Boulder
Highly Opinionated, Aging  and                      [e-mail]
Perpetual Student of Chemistry and Physics.
            Write me for an argument on your favorite subject.

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

Date: Fri, 14 Aug 1992 01:15:52 GMT
From: Timothy Banks <[e-mail]>
Subject: Solar System Journal
Newsgroups: sci.space

>
>The other example of space piracy?  A perfectly healthy
>working earth orbiting satellite that was shot down to
>test and probably also give PR boosts to SDIO, 4-5 years
>ago.  You can bet the scientific investigators were mad
>about that one as well.
>

    Ah..I have a feeling you are talking about a satellite
    that was still producing good solar observations. It is
    mentioned in Donat Wentzel's book _The Restless Sun_
    (Smithsonian). Unfortunately I don't have a copy to hand
    to look the details up....

--
  Timothy Banks, Physics Department, Victoria University of Wellington, NZ.
       bankst@kauri|rata|matai.vuw.ac.nz, [e-mail].
    "He's dead, Jim!" "OK, you take the tricorder, I'll take the wallet!"

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

Date: 14 Aug 92 05:40:00 GMT
From: [e-mail]
Subject: SPS feasibility and other space development
Newsgroups: sci.space

All I can say is Wow! I have been reading many many posts on SPS and the topic
of space development and I am very impressed with what I have read.  I will not
attempt to answer the posts. I don't have enough time to say all of the things
that I would like to say I do put this out for your consideration as a set of
fundamental principles for space development including SPS.

Use history as a guide.

Space is not some unique adventure taken in the context of the history of
man. Our recent (last 550 years) history is rife with examples that can be
taken as analogs to space development.  The Spanish and Portugese "space race"
was undertaken for commercial purposes. One of the leading commodities of the
15th century was spice for foods. There was an insatiable demand for spice
to liven up foods that had been very bland since the fall of Rome and Roman
trade.  The spice islands were the intended destination of Christopher Columbus
not the new world. Lowering the cost of transportation was the driving element
of the Spanish/Portugese expansion.  (Sound Familiar?)

It is also history that it was other commodities that were discovered after the
voyages of Columbus that really sparked the move to the new world. (read Gold)
The Conquistadors would have never come and indeed did not go to places such
as Mali and Ghana in Africa to pillage because the larges profit was to be
made in the new world with its uncharted riches. It was never in the minds
of the early explorers that they would be responsible for the largest single
increase in the European standard of living ever known by the taking of the
potato back to Europe.  This one plant did more to increase the availability
of food than any other discovery and for that reason is more valuable than the
Gold taken from the Americas. There is a myriad of such stories of the
discovery of some plant that changed forever the lives for the better for the
Europeans. There are some books written on this subject that I do not remember
the name of that will illustrate the importance of these discoveries.

We have not scratched the surface at all in the exploration and developement
of space.  We need to change the foci somewhat from the grand discoveries of
great things to a thourough search mission for resources that will increase
the wealth of our planet.  No longer do we have to rely on the hit or miss
propostion of discovery of ages past.  In this new area we do not have anyone
to fight but the dangers of uncharted territory. Just gaining the ability to
handle the 1986A nickel iron asteriod with its trillion dollars worth of
Platinum and 90 billion dollars worth of gold would pay for all of the grand
plans that are put forth.  This is just one of thousands that exist in the
inner solar system.  Look at the moon; each crater is a potential bulls eye
for the brother of 1986 A. I am encouraged at some of the things that JPL
is doing in this area that they are not talking about. I will let Ron let
the cat out of the bag on that stuff.

To catagorically state that the developement of the other 99 percent of the
matter of the solar system is uneconomical is simply the manifestation of
a geocentric attitude. I do not think that any of these technologies and or
systems will in and of themselves make an overwhelming argument for the
exploration and developement of space. (except for a closer flyby of a relative
of 1986A that could be exploited) BUT taken together the technologies and
systems proposed for this or that purpose to solve this or that problem will
more than justify the investment of resources necessary to bring these
projects to fruition.

I apologize to everyone for my flame post. It just irks me to no end to be
criticized for not publishing numbers accurate to ten digits by anyone who
uses only rhetoric with no supporting numbers to argue a point. I wish I
had the time to sit down on here and truly engage in a detailed analysis of
these systems.  I admire Allan Sherzier even if he does fudge the numbers a
magnitude:-) or so because he at least will put in several hours of research for
his posts as well as step direction in the  path of the flame throwers who
take issue with his ideas. What I will not tolerate is folks who from a
postion of authority simply denegrate an idea for what ever reason and I posted
in detail a response to the person who I flamed who wrote me.

We are in a difficult time for the exploration and development of space. Other
interests have won the public relations battle for dollars in Congress with most
of us to busy shooting ourselves and each other in the foot to notice. I heard
that the NSS office in DC is up for sale.  That is a sad testimony to our
inability to get a message across.  The dream is still alive and has just
as much potential as it ever has. It is up to people such as the ones on this
net who will do the leg work that it takes to develop the counterargument
to those who wish us to all live a limited life and be content with less.

Dennis, University of Alabama in Huntsville

PS

I heard some interesting news today.  The NASA Marshall Space Flight Center,
the birthplace of our Saturn Class dreams has awoken the giant.  The only
test stand in the West that was ever used to hold down a Saturn Class rocket
for a full up test firing of the Saturn V first stage is about to rumble again!

Side A has been used for the last four years as an SSME test bed evaluation
stand for firings of SSME's with the Pratt Whitney Turbopumps and other
SSME modifications.  FUNDING HAS BEEN OBTAINED AND WORK IS IN PROGRESS TO
BRING A SATURN V F1 ENGINE OUT OF STORAGE AND RETURN IT TO FIRING STATUS. Take
that and stick it in your pipe and smoke it. One engine has been brought out
and has been cut apart to determin just how it was put together in the first
place by the UAH propulsion group in concert with the MSFC propulsion branch.
A second F1 will be refurbished partly to see what is involved and the engine
will be test fired on the other side of the test stand where its five siblings
where fired together in 1964-65. I will of course post progress reports as I
hear them and will put out a message when firing time nears so that you poor
poor deprived folks out there who do not live in Huntsville can get a chance
to hear the engine heard round the solar system.

*************************************************************************
Revive the Saturn V!
*************************************************************************

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

Date: 10 Aug 92 17:50:59 GMT
From: Paul Campbell <taniwha!paul>
Subject: Two questions about the shuttle tethered satellite experiment
Newsgroups: sci.space,sci.space.shuttle

In article <[e-mail]> [e-mail] (Alan Kilian) writes:
>1) The shuttle is at one end of a conductive wire. The satellite is at
>   the other. If the wire moves through a magnetic field you can generate
>   an electric potential. Now how do you measure the potential?
>   They were hoping for 5000 Volts on a 12 Mile tether but got 40 Volts
>   on a 750 Feet tether.

Which scales up to ~3400V on a 12 mile tether - not bad ...... does anyone
know if the electron guns need some minimum voltage to start to run efficiently?

>3) (I know I said two but what the heck) How can you use the potential
>   from the one wire tether?

Run it backwards, get a satelite pair into LEO between a tether, use solar cells
to pump electrons and move you (very slowly) to a higher orbit. Maybe set it
up as a tug that moves back and forward. If you want to shunt a lot of stuff
into high orbit this may be the way to do it, boost it all up to LEO start it
moving up, keep doing this for 3-4 years at which time it starts to arrive
at L5 or wherever you want to use it, at which time you detach the tug and
send it back for more (with a lower mass the trip back will be a lot faster).

    Paul

--
Paul Campbell    UUCP: ..!mtxinu!taniwha!paul     AppleLink: CAMPBELL.P

    "'Potato', not 'Potatoe'"
        Bart Simpson - on the blackboard 6/25/92

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End of Space Digest Volume 15 : Issue 109
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