Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_3/V16NO380.TXT

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Date: Sun, 28 Mar 93 05:10:49
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #380
To: Space Digest Readers
Precedence: bulk


Space Digest                Sun, 28 Mar 93       Volume 16 : Issue 380

Today's Topics:
Gravity waves, was: Predicting gravity wave quantization & Cosmic Noise
                          How to cool Venus
         Predicting gravity wave quantization & Cosmic Noise
                       Space Ship - Outer Space
                Space Station Redesign: Constellation
Speculation: the extension of TCP/IP and DNS into large light lag enviroments
                          Terraforming Venus
           the call to space (was Re: Clueless Szaboisms )
            Timid Terraformers (was Re: How to cool Venus)
                  way off topic, Was something else
               Where do they get Ti slag from (3 msgs)

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Date: Sun, 28 Mar 1993 02:42:50 GMT
From: Tom Van Flandern <[e-mail]>
Subject: Gravity waves, was: Predicting gravity wave quantization & Cosmic Noise
Newsgroups: sci.space,sci.astro,sci.physics,alt.sci.planetary

[e-mail] (Cameron Randale Bass) writes:

> [e-mail] (Bruce Scott) writes:

>> "Existence" is undefined unless it is synonymous with "observable" in
>> physics.

> [crb] Dong ....  Dong ....  Dong ....  Do I hear the death-knell of
> string theory?

     I agree.  You can add "dark matter" and quarks and a lot of other
unobservable, purely theoretical constructs in physics to that list,
including the omni-present "black holes."

     Will Bruce argue that their existence can be inferred from theory
alone?  Then what about my original criticism, when I said "Curvature
can only exist relative to something non-curved"?  Bruce replied:
"'Existence' is undefined unless it is synonymous with 'observable' in
physics.  We cannot observe more than the four dimensions we know about."
At the moment I don't see a way to defend that statement and the
existence of these unobservable phenomena simultaneously.  -|Tom|-

--
Tom Van Flandern / Washington, DC / [e-mail]
Meta Research was founded to foster research into ideas not otherwise
supported because they conflict with mainstream theories in Astronomy.

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

Date: 28 Mar 93 02:07:38 GMT
From: James Thomas Green <[e-mail]>
Subject: How to cool Venus
Newsgroups: sci.space

It sounds like the idea of nukes at Venus is to heat the
atmosphere and cause it to expand to beyond escape velocity.  I
thought of another, if slower way to accomplish the same thing.
Huge solar mirrors could reflect and concentrate sunlight on
Venus.  The atmosphere would get hotter and thus expand until
a large amount of it is gone.

I leave it as an exercise to the interested how much surface
area of mirrors and time would be required.


                                                                  A/~~\A
                                                                 ((O  O))___
                                                                   \  /     ~~~
  #                       #                         #              (--)\    #
--#---x---x---x---x---x---#---x---x----x----x---x---#---x---x---x---x---x---#---
  #    James T. Green     # [e-mail] #                    \  #
--#---x---x---x---x---x---#---x---x----x----x---x---#---x---x---x---x---x---#---
 \#//  \|/    \\\|||//   \#/   \\\||/   \||///    \\#|//     \\\\\|||/// \|/#\|
                              O u t s t a n d i n g   i n   t h e   f i e l d !

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

Date: 27 Mar 93 02:19:32 GMT
From: William Reiken <[e-mail]>
Subject: Predicting gravity wave quantization & Cosmic Noise
Newsgroups: sci.space,sci.astro,sci.physics,alt.sci.planetary

In article <[e-mail]>, [e-mail] (Gary Coffman) writes:
>
> I could write a book on what I don't know about gravity waves.
>

    Go ahead and do it.  Maybe if you write such a book. Those who do
know everything about them will have a better idea on what to write about.
So in the end, it will help everyone.  You could call it "What I don't know
about gravity waves, by Gary Coffman"  This is not a critical comment, no puns
intended and no Joke, just a thought.  Maybe those experts out there should
think about it as well.  Since this is a very difficult subject for most
people to understand.

                        Will...

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

Date: Sat, 27 Mar 93 21:31:30 EST
From: John Roberts <[e-mail]>
Subject: Space Ship - Outer Space

-From: [e-mail] (David Lai)
-Subject: Space Ship - Outer Space
-Date: 26 Mar 93 17:57:25 GMT
-Organization: The University of British Columbia

-Hi netters,

-    I remember that a spacecraft was around the nineth planet some
-years ago.  Is there any spacecraft travelling beyond the nineth planet
-now?  If so, what discovery has it make?  Can it still communicate with
-the Earth?

Voyager 2 flew by Neptune, which was the ninth planet at the time (but
usually isn't). Yes, DSN is still in contact with Voyager 2.

John Roberts
[e-mail]

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

Date: Sat, 27 Mar 1993 23:50:21 GMT
From: Nick Szabo <[e-mail]>
Subject: Space Station Redesign: Constellation
Newsgroups: sci.space

Let's step back and consider the functionality we want:

[1] microgravity/vacuum process research
[2] life sciences research (adaptation to space)
[3] spacecraft maintenence

The old NASA approach, explified by Shuttle and SSF, was to
centralize functionality.  These projects failed to meet
their targets by a wide margin: the military and commercial users
took most of their payloads off Shuttle after wasting much effort to
tie their payloads to it, and the original SSF concept has failed
in a jumble of disorganization and lack of end-user support.
Over $50 billion has been spent on these two projects with no
reduction in launch costs and little improvement in commercial space
industrialization.  Meanwhile, military and commercial users have
come up with a superior strategy for space development: the
constellation.

Firstly, different functions are broken down into different
constellations placed in the optimal orbit for each function:
thus we have the GPS/Navstar constellation in 12-hour orbits,
comsats in Clarke and Molniya orbits, etc.  Secondly, the task
is distributed amongst several spacecraft in a constellation,
providing for redundancy and full coverage where needed.

SSF's 3 main functions require quite different environments
and are also prime candidates for constellization.

[1] We have the makings of a microgravity constellation now:
COMET and Mir for long-duration flights, Shuttle/Spacelab for
short-duration flights.  The best strategy for this area is
inexpensive, incremental improvement: installation of U.S. facilities
on Mir, Shuttle/Mir linkup, and transition from Shuttle/Spacelab
to a much less expensive SSTO/Spacehab/COMET or SSTO/SIF/COMET.
We might also expand the research program to take advantage of
interesting space environments, eg the high-radiation Van Allen belt
or gas/plasma gradients in comet tails.  The COMET system can
be much more easily retrofitted for these tasks, where a
station is too large to affordably launch beyond LEO.

[2] We need to study life sciences not just in microgravity,
but also in lunar and Martian gravities, and in the radiation
environments of deep space instead of the protected shelter
of LEO.  This is a very long-term, low-priority project, since
astronauts will have little practical use in the space program
until costs come down orders of magnitude.  Furthermore, using
astronauts severely restricts the scope of the investigation,
and the sample size.  So I propose LabRatSat, a constellation
tether-bolo satellites that test out various levels of gravity
in super-Van-Allen-Belt orbits that are representative of the
radiation environment encountered on Earth-Moon, Earth-Mars,
Earth-asteroid, etc. trips.  The miniaturized life support
machinery might be operated real-time from earth thru a VR
interface.  AFter several orbital missions have been flown,
follow-ons can act as LDEFs on the lunar and Martian surface,
testing out the actual environment at low cost before $billions
are spent on astronauts.

[3] By far the largest market for spacecraft servicing is in
Clarke orbit.  I propose a fleet of small teleoperated
robots and small test satellites on which ground engineers can
practice their skills.  Once in place, robots can pry stuck
solar arrays and antennas, attach solar battery power packs,
inject fuel, etc.  Once the fleet is working, it can be
spun off to commercial company(s) who can work with the comsat
companies to develop comsat replaceable module standards.

By applying the successful constellation strategy, and getting
rid of the failed centralized strategy of Shuttle and SSF, we
have radically improved the capability of the program while
greatly cutting its cost.  For a fraction of SSF's pricetag,
we can fix satellites where the satellites are, we can study
life's adaptation to a much large & more representative variety
of space environments, and we can do microgravity and vacuum
research inexpensively and, if needed, in special-purpose
orbits.

N.B., we can apply the constellation strategy to SEI as well, greatly
cutting its cost and increasing its functionality.  MESUR and
Artemis are two good examples of this; more ambitiously we can
set up a network of native propellant plants on Mars that can be used
to fuel planet-wide rover/ballistic hopper prospecting and
sample return.  The descendants of LabRatSat's technology can
be used as a Mars surface LDEF and to test out closed-ecology
greenhouses on Mars at low cost.


--
Nick Szabo                     [e-mail]

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

Date: Sun, 28 Mar 1993 00:25:18 GMT
From: "Phil G. Fraering" <[e-mail]>
Subject: Speculation: the extension of TCP/IP and DNS into large light lag enviroments
Newsgroups: alt.internet.services,sci.space

[e-mail] (M. Sean Bennett) writes:

>>Why is it a dangerous precedent? Should NASA or the CIS be building bases
>>that aren't under any jurisdiction?

>It is my fault for not making myself clearer.

>The Moon, Mars, etc. are "claimed for all mankind".

>The dangerous precedent is the exporting of our national bigotries - irespective
>of the nation involved.

It's not really dangerous; what _is_ dangerous, is the regime you outlined
above, which was implemented by the COPOUS Treaty.

>What is this COPOUS treaty you speak of?

A treaty that gave space "to all mankind;" literally, it gave _any_ nation
on the face of the earth veto power over anything done by anyone up there.

The death-squad-installed presidents of Honduras or Cuba would have
just as much say in being able to stop space exploration as the
heads of state of any other countries. In short, space exploration
becomes even more of a hostage to tyrranical politicians, wheras
in my opinion (which I do not think is humble, but is as close to
absolute truth as humans get) it should not be hostage to any politicians
at all.

Go look up the COPOUS treaty and the debate surrounding it before you
come back to flame. Please.

>Sean

--
Phil Fraering         |"...drag them, kicking and screaming,
[e-mail]|into the Century of the Fruitbat." - Terry Pratchett,
                       _Reaper Man_

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

Date: Sat, 27 Mar 93 22:42:07 EST
From: John Roberts <[e-mail]>
Subject: Terraforming Venus

-From: [e-mail] (Michael Robert Williams)
-Subject: Re: How to cool Venus
-Date: 26 Mar 93 17:17:28 GMT
-Organization: University of Virginia

-But, to the point, several people have been talking about using large
-nuclear bombs (should that be "tools"?) to blast a large fraction of Venus's
-atmosphere away. I read a really fascinating book a few years back called
-"ThPhysical Principles of Thermonuclear Explosive Devices" that had a
-chapter called "On Creating Thermonuclear Explosives of Arbitrarily Large
-Size." It seemed pretty easy, at least conceptually; the author even says
-something about blowing most of the atmosphere of the Earth away with a
-suprisingly small bomb.

-Does anybody with more experience in the field than I have (i.e. any at all)
-have any idea if this sort of thing is truly possible, or was the author
-improperly scaling his results?

As you wisely point out, it's vitally important to try to plug in actual
numbers to see if the idea makes any sense at all. I seem to have taken the
results offline from the last time the math was worked out, but it came out
as a really ridiculous expenditure of effort - the hydrogen bomb to do the
job would make a pretty respectable moon. Paul Dietz may still have the
calculations.

It's not too hard to come up with a rough idea of the amount of energy
required to do the job. First, calculate the total mass of Venus's
atmosphere, which will be approximately the surface area multiplied by
the surface pressure, divided by (Venus surface gravity / Earth surface
gravity). Second, calculate the escape velocity from the surface of
Venus (ignoring air resistance for the moment - that shouldn't matter
because the effect of air resistance is to heat the atmosphere, and that's
what you're doing anyway) - it should come out fairly close to Earth
surface escape velocity. Third, use the formula E = 0.5 mv^2 to calculate
the amount of kinetic energy that needs to be put into the mass of the
atmosphere to accelerate it to escape velocity. That should be adequate for
a first guess. You can subtract 1 or 2 percent from that number because you
want to leave a some of the atmosphere there, but you probably have to
add a large amount to account for inefficiency of the operation - the planet's
crust will take up some of the energy.

To calculate the mass of explosive material, you could start with
antimatter - divide the amount of energy by the speed of light squared
(~9E16 in SI units), then divide by 2 because antimatter annihilates an
equal mass of ordinary matter. Unless I slipped a decimal point, that
means you'd need on the order of hundreds of millions of tons of antimatter.
Hydrogen fusion is far less efficient than antimatter (I don't have the
number handy), so you'd have to multiply the antimatter mass by some large
number if you want to do it with fusion. Anybody who still thinks it's
a good idea can do the above calculations, then explain where they're
going to get all that deuterium, tritium, etc.

The idea of seeding the atmosphere with microorganisms to break down the
carbon dioxide might be workable if there were other constituents in the
atmosphere, but it doesn't seem practical with the atmosphere that's there.
The surface and lower atmosphere are *much* hotter than any known Earth life
can survive (proteins, the basic constituents, just aren't designed to
operate at that temperature), so interaction with the surface materials
isn't possible - the organisms couldn't trap the CO2 in the chemical
structure of the rock. Just getting rid of the carbon and leaving the
oxygen wouldn't be the answer either - at near-present Venus atmospheric
pressure, oxygen would be far more deadly than the current CO2 atmosphere.
It would be extremely difficult for organisms to survive at all in the
atmosphere, because the atmosphere is *very* turbulent - particles floating
at an altitude with survivable temperature would soon find themselves swept
down to hotter regions.

There *is* a possibility for terraforming - enormous numbers of large
comets might be forced to collide with Venus, gradually blasting away the
atmosphere and replacing the water Venus once had. There probably aren't
enough comets in the planetary system to do the job, but you might be able
to find them in the Oort cloud. The energy to shoot the comets to Venus
directly would be prohibitive, but with very clever planning it may be
possible to give the comets small nudges which will cause them (many
years later) to interact with other bodies by collision or gravitational
slingshot, and these secondary interactions would provide most of the
energy (delta-V) needed to get the comets to Venus. You might even design
the secondary interactions so that they cause tertiary interactions with
even larger bodies, giving a multiplying effect. Humans might be able
to manipulate sufficient energy to provide the fine guidance to keep all these
bodies on track.

However, there's a fundamental problem even with the colliding-comet approach -
if humans are sufficiently powerful and skilled in space operations to
manipulate large bodies in this way, then it would be an incredible waste to
expend so much effort on Venus, because so many other useful things could be
done. However you look at it, terraforming Venus just isn't worth it. You
could probably build space colonies with aggregate floor space equal to the
surface area of Venus for less effort than it would take to terraform Venus.
The only way in which it might be worthwhile is as a novelty, at such time
as humans become so powerful that it's a trivial effort and can be paid for
out of petty cash - at which time we ought to get to other star systems and
find planets that are easier to terraform.

Of course, colonization is a different matter from terraforming. I've
posted several ideas by which it ought to be possible to establish a
robotic outpost or even a manned colony on the surface of Venus. It
would be terribly expensive (orders of magnitude more expensive than a
moon colony), and not worth much when it was done - perhaps it could be
argued that it might be done out of scientific interest.

John Roberts
[e-mail]

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

Date: Sun, 28 Mar 1993 00:07:12 GMT
From: "Phil G. Fraering" <[e-mail]>
Subject: the call to space (was Re: Clueless Szaboisms )
Newsgroups: sci.space

[e-mail] (Pat) writes:


>Will  blats about how  japan is going to rise again on a nuclear phoenix.

>Please document the ROI for Nuclear Power,  once all costs have been
>allocated.

>pat

Simple. The Japanese trade deficit wrt Saudi Arabia is much much
larger than their trade surplus wrt the United States. If the latter
causes problems in the United States, which wrt "cultural values"
has much more in common with Japan than Japan has with Saudi Arabia,
can you imagine the political pressure they are under to find something
better? _Especially_ since they're not going around pretending the
mid-70's oil crisis never happened...

Oh, you mean economics? Well, once you get rid of all the regulations
that don't improve safety while increacing the cost and generally
making the industry untenable (which may be their intended effect)
nuclear is probably a pretty good deal...

--
Phil Fraering         |"...drag them, kicking and screaming,
[e-mail]|into the Century of the Fruitbat." - Terry Pratchett,
                       _Reaper Man_

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

Date: 27 Mar 93 02:28:25 GMT
From: William Reiken <[e-mail]>
Subject: Timid Terraformers (was Re: How to cool Venus)
Newsgroups: sci.space

    Hey you guys, I have posted a question about Venus.  I would like
to know:

    ""What is the total composition of the Atmosphere of Venus?""

    That means every little element, etc. ever detected in its Atmosphere.
If you can give me the percentage ratios that would also be very welcomed.


                        Will...

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

Date: 27 Mar 93 15:43:53
From: Steinn Sigurdsson <[e-mail]>
Subject: way off topic, Was something else
Newsgroups: sci.space,talk.politics.space,sci.energy

Note redirected followups

In article <1p261c$[e-mail]> [e-mail] (Pat) writes:

   Will  blats about how  japan is going to rise again on a nuclear phoenix.

well, Japan is investing heavily both in conventional fission plants
and breeders, although contending the opposition is governement
controlled seems rather paranoid

   Please document the ROI for Nuclear Power,  once all costs have been

   allocated.

Japan has negligible internal oil or coal supplies, they are extremely
vulnerable to embargoes and supply cutoff, with energy as with rice,
I expect they will happily toss the Harvard business school attitude
out the window and go with long term security of supply.

*  Steinn Sigurdsson                Lick Observatory           *
* [e-mail]               "standard disclaimer"        *
* But, oh, love is strange                       *
* and you have to learn to take the crunchy with the smooth,      *
* I suppose                               - B.B. 1983 *

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

Date: 28 Mar 93 01:21:50 GMT
From: [e-mail]
Subject: Where do they get Ti slag from
Newsgroups: sci.space

Hello
Where do they get Titanium slag from. I know the end product goes
on a variety of space product, but where does the ore itself
come from

Regards
NEil

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

Date: Sun, 28 Mar 1993 01:58:44 GMT
From: Jeff Bytof <[e-mail]>
Subject: Where do they get Ti slag from
Newsgroups: sci.space

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

>Where do they get Titanium slag from. I know the end product goes
>on a variety of space product, but where does the ore itself
>come from

From "General Chemistry", McQuarrie and Rock, pp. 894-895:

"...The second most common transition metal is titanium, which
constitutes 0.6 percent of the earth's crust by mass.  Pure
titanium is a lustrous, white metal.  It is used to make
lightweight alloys that are stable at high temperatures for use
in missiles and high-performance aircraft.  Titanium is as
strong as most steels but 50 percent lighter.  It is 60 percent
heavier than aluminum, but twice as strong.  In addition, it has
excellent resistance to corrosion.  The most important ore of
titanium is rutile which is primarily TiO2.  Pure titanium metal
is produced by first converting TiO2 to TiCl4 and then reducing
the TiCl4 by reacting it with magnesium.  Most titanium is used
in the production of titanium steels, but TiO2, which is white
when pure, is used as a white pigment in many paints.  Titanium
tetrachloride is also used to make smoke screens; when it is
sprayed into the air it reacts with moisture to produce a dense and
persistent white cloud of TiO2."

["Deposits of rutile are found in Georgia, Virginia, Australia,
Brazil, Italy and Mexico."]

Question: what is the predominate mineral containing titanium on
the moon?

-rabjab

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

Date: Sun, 28 Mar 1993 02:25:30 GMT
From: Paul Dietz <[e-mail]>
Subject: Where do they get Ti slag from
Newsgroups: sci.space

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

> Hello
> Where do they get Titanium slag from. I know the end product goes
> on a variety of space product, but where does the ore itself
> come from

Titanium is obtained from various oxide minerals, such as ilmenite
(FeTiO3), rutile and anatase (alpha- and beta- TiO2).  These minerals
occur in many places, including Australia, Russia, the USA, and
elsewhere.

Most titanium ore goes into making TiO2 for use as a pigment in paints
and paper (it replaced lead compounds as the white pigment in paint.)
Only a small amount goes into production of titanium metal.

The market price of ilmenite concentrate is rather low, less than
$.10/lb.  Titanium metal is expensive because the refining process
is expensive, not because the ore is rare or expensive.

    Paul

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

End of Space Digest Volume 16 : Issue 380
------------------------------