Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_6/V16NO624.TXT

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Date: Tue, 25 May 93 05:19:56
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #624
To: Space Digest Readers
Precedence: bulk


Space Digest                Tue, 25 May 93       Volume 16 : Issue 624

Today's Topics:
                  Boeing TSTO concept (sort-of long)
                   Carl Sagan, respected astronomer
                       Dark sky property rights
              Detecting planets in other system (2 msgs)
                  Hey Sherz! (For real!) Cost of LEO
           Interesting DC-X paper I cama accross. (2 msgs)
                             Killing ET's
                       LE-7 CAPTIVE FIRING TEST
                   Looking for rocketry software...
                              Moon Base
                   Moon vs. asteroids, Mars, comets
                             New DC-X GIF
                      Pros and cons of the Moon
                    Soyuz and Shuttle Comparisons

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

Date: Tue, 25 May 1993 01:28:16 GMT
From: Mary Shafer <[e-mail]>
Subject: Boeing TSTO concept (sort-of long)
Newsgroups: sci.space

On Sun, 23 May 1993 14:47:41 GMT, [e-mail] (Gary Coffman) said:

Gary> Even the simple aluminum honeycomb
Gary> structures used on B-58 and B-70 should be adequate to the task.
Gary> If you want overkill, substitute titanium for aluminum in the
Gary> leading edges.

The XB-70 was made of stainless steel honeycomb and it was anything
but simple.

(I think that it also had some titanium, but am not certain.  The
first time I saw the plane after it left Edwards, it was parked
outside at the Air Force museum at Wright-Patterson.  It was weeping
rust from all the joints, even though it had just been freshly
painted.  They've got it indoors _now_ but I suspect it's too late.)

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

Date: Mon, 24 May 93 22:01:31 EDT
From: Tom <[e-mail]>
Subject: Carl Sagan, respected astronomer

Olaf Vancura sez;
>>...Carl Sagan is a well respected astronomer
>>who teaches at Cornell.

Frank Crary responds;
>Have you ever read any of his professional papers? The one I look up
>last month, for example, was truely pathetic (Wallace and Sagen's
>1979 paper on the stability of water on Mars, under an insulating
>layer of ice.) While it was an interesting idea, their model was
>completely and obviously bogus (unless you think it's safe to assume
>five meters of ice is totally transparent, among other things...)
>A later paper, that reworked the model in a vaguely realistic
>manner got a very different result.

Well, well-respected in some circles.  BTW, he isn't an astronomer.  He's
an astro-biologist.  At least, that's what his degree is in.  It's quite
an accomplishment to get a degree in something whose subject matter
doesn't actually exist.  Well, carbon compounds...

The story I heard is that after his defense, the astronomers were shaking
their heads, muttering "Well, at least he knows biology" and the
biologists were shaking their heads, saying "Well, at least he knows
astronomy".  :-)

Any respect Sagan has in professional circles, from what I gather, is due
to his influence on students and the public at large, in creating
interest and support for astronomy and science in general.

-Tommy Mac
-------------------------------------------------------------------------
Tom McWilliams 517-355-2178 wk   \ They communicated with the communists,
[e-mail] 336-9591 hm \ and pacified the pacifists. -TimBuk3
-------------------------------------------------------------------------

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

Date: Mon, 24 May 93 15:55:05 PDT
From: Charlie Prael <[e-mail]>
Subject: Dark sky property rights
Newsgroups: sci.astro,sci.space,sci.econ

[e-mail] (Jim Hart) writes:

> Nope.  "Freedom of the Skies" treaties state that national soveriegnty
> stops at the edge of the atmosphere.  No nation has jurisdiction over
> this case, so it must be settled by private arbitrators, much the

Actually, that doesn't mean anything of the sort.  A more realistic
option is a multi-national arbitration commission, sponsored under the
UN.  You repeatedly expect the government to take a back seat on this.
They won't.

> same way the radio spectrum was divided up before the FCC stepped

Ummm, are you aware of *who* divided up the radio spectrum?  It was a
subgroup of the League of Nations -- predecessor of the UN.  There aren't
any private representatives there -- it's all governmental appointees,
representing governments.

> in and usurped it, and much the way Internet and Usenet flourish
> internationally with no FCC regulations.  My suggestion is that the

Really?  Stop and take a look at (a) who sponsored these nets in the
first place (Can you say ARPA?), and (b) how much regulations the
networks undergo in their creation and maintenance, both within this
country and in other countries.

> arbitrators create a fungible, tradable property, a win-win solution,

Maybe, but we're back to the question of who gets 'em.  It's only a "win"
solution for the people who are enfranchised to dark sky rights.  Using
your criteria, that is a narrow group of astronomers.  That's like
making the only people who are qualified to make chemical waste policy
the people who make and use those chemicals.  What about the rest of us,
who don't buy or sell those chemicals, but are effected by them
nonetheless?

> instead of a win-lose absolutist solution of judging completely in favor
> of one side or the other.
>
> As for "disenfranchising" casual stargazers, they were never enfranchised

See the above argument.  You're arguing that a narrow criteria is the
only one possible for input.  That doesn't really work very well, now
does it?

> in the first place; they have not invested in ground-based astronomy.
> Practically, there is no way except money for dark sky users to
> measurably demonstrate their level of commitment.  If they want a piece
> of the action they can go down to the local telescope shop, buy a nice
> beginner's kit, and swap their receipts for megacandle certificates.  I'm

Actually, by that logic, I can claim a "piece of the action" by going
into my opthamologists, and paying for a pair of contacts, or glasses.
I've invested money in the ability to see things in the sky at night.
Or, if it is my chosen hobby to go lie out on a sailboat, looking at the
stars, I can claim that sailboat (or a portion thereof) as a legitimate
investment in ground-based (or water-based, here) astronomy.  Where does
it stop?

> not claiming this is 100% fair, but the property rights have to be defined
> somehow.  No totally fair solution is possible, but distributing the
> property among astronomers by their proportion of investment in ground-based
> astronomy is reasonably fair, eg it is far fairer than deciding absolutely
> and inflexibly in favor of one side or the other.
>
> If a U.S. court refuses to recognize those property rights, eg by deciding
> to ban adsats that have properly purchased megacandles, they will have to

You've also got the problem of deciding who's got the right to issue
megacandle certificates.  Are they an international organization?  A
national one?  A corporation?  One operating under which national laws,
with what international authorization.  Are megacandle certs transferable
from country to country, or are they valid only within the country of
origin?  What happens if a satellite with it's lights on shines into a
country it doesn't have legitimate certification for?

> enforce the ban by violating the international treaties and shooting down
> the adsat when Russia or Europe, China, Japan, Brazil, Kazakhistan, India,
> Israel, Pakistan, etc. launches it.  The chances of this are small
> enough insurance will cover it.  I also  hope my country is not so
> stupid and hypocritical as to promote free enterprise and then
> violate both property rights and international treaty is such
> a violent and polluting manner.
>
> Jim Hart
> [e-mail]


Jim, overall, this is *really* poorly thought out.  As you can see from
the above, there are just a *few* loopholes.  Give me time, and a few
lawyers, and I can shoot LOTS of holes in it.

See the problem?

------------------------------------------------------------------
Charlie Prael  - [e-mail]
Shakala BBS (ClanZen Radio Network) Sunnyvale, CA [phone]

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

Date: 24 May 93 16:57:36 GMT
From: [e-mail]
Subject: Detecting planets in other system
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Frank Crary) writes:
> In article <[e-mail]> [e-mail] writes:
>>For Earthlike planets you'll need something along the lines of a 16m telescope
>>of the moon.

Someone mentioned the chance of using an astrometric telescope to do this, and
that is perfectly correct. In this case you use the movements of the partent
star to trace the mass distribution in the system, similar to the 'wobble'
approach used to look for extrasolar planets from the earth.

>
> Actually, an interferometer(sp?) array in the thermal IR has a reasonable
> chance, if you can get a couple of orbital telescopes and a baseline
> of ~500,000 km. In the thermal IR the signal to noise (i.e. star's
> flux to that of the planet) is greatest, since you are in the peak of
> the planet's Plank curve but well away from the star's peak.
>
Use of thermal IR is certainly a good idea. The use of an interferometer
pair/trio with one element in orbit, or more, is a bit tougher though. To do
interferometry you need to fix the position of the antennae (or measure it) to
consierably less than the wavelength of the radiation you're observing. This
may be possible (though hard) in the radio, at metre wavelengths, where QUASAT
and Radioastron have been proposed. Scaling that technology up by 5 orders of
magnitude to 10 microns isn't going to be easy!!!

If you want to do interferometry in the optical/IR, the ground or the moon is
the best place for it as you then have a nicely solid base to stop things
moving. Optical interferometers, like COAST, are in fact currently underway.
However, if they are like radio interferometers, they are likely to have a
pretty poor dynamic range, which is the one thing you need when looking for
planets. So filled aperture methods are likely to remain the best bet...


>                                                    Frank Crary
>                                                    CU Boulder
--
================================================================================
Dave Clements, Oxford University Astrophysics Department
================================================================================
clements @ uk.ac.ox.vax            |  Umberto Eco is the *real* Comte de
dlc      @ uk.ac.ox.astro        |           Saint Germain...
================================================================================

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

Date: Tue, 25 May 93 02:54:57 BST
From: Ata Etemadi <[e-mail]>
Subject: Detecting planets in other system
Newsgroups: sci.space

Anyone considered using Kilometric radiation ? I know we're being bathed in
it but it shouldn't be too difficult to filter out the near-Earth stuff using
two sensors (since its coming from close by). Planets with magnetic fields would
likely be emitting coherent radiation at these wavelengths making the job a
little easier. What you need is an underwater detector to filter out some of the
noise, since Kilometric radiation penetrates water a long way down. This would be
a darn good use for all those nuclear submarines out there. BTW I think the
military use this wavelength of radiation for communicating with their subs.

    best regards
        Ata <(|)>.

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

From: Pat <[e-mail]>
Subject: Hey Sherz! (For real!) Cost of LEO
Newsgroups: sci.space

Date: 24 May 1993 18:52:25 -0400
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Mass Return.

Ken seems fixated on this measure of performance.

I would suggest that we not look at mass returned,  but Useful
Cargo Returned.

In that Case we have,  1 LDEF,  4-5 SpaceLab flights,  and probably
appx 100 GAS Cans.

I am assuming that ASTRO  could have flown as Expendables  on a
extended science mission and abandoned in orbit as opposed to
abandoned in warehouse  like it is now.

Not a lot for 12 years of missions.  The soviets probably have
returned as much using capsula  vehicles and with soyuz.

pat

    Read this weeks space news for an editorial written by
a russian,  scathing BURAN and how much money it wasted.
Great quote  "DOn't make it better,  make it like the
American's"

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

Date: 24 May 1993 18:58:12 -0400
From: Pat <[e-mail]>
Subject: Interesting DC-X paper I cama accross.
Newsgroups: sci.space

How about also?

We are going ahead  with plans to build a couple more prototypes....

or

WE got enough data to Justify the DC-X'  (DC-XA)

and we will enhance the test program from there.

pat

who really thinks a test program needs more then just one
X vehicle.  THe X-1  had 3???  the 15  had 3,  and i don't
know about the others.

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

Date: 24 May 1993 19:00:06 -0400
From: Pat <[e-mail]>
Subject: Interesting DC-X paper I cama accross.
Newsgroups: sci.space

So what's the Serial number of the DC-X?

Maybe they should give it 6062, cuz that was the number
for yeagers bird.

pat

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

Date: Mon, 24 May 93 21:43:30 EDT
From: Tom <[e-mail]>
Subject: Killing ET's

[Is killing an ET legal?]

Pat sez;
>>I think the Endangered Species act may apply.  Also interfering with
>>Diplomatic relations, and violsating the nuetrality act.

Gary responds;
>...
>A diplomat has no status until his credentials are accepted by the
>authorities of the country to which he is posted.
>...

Um, this brings up an important question.  What if it's illegal to kill
an ET, according to his (it's) laws, and their authorities are powerful
enough to make us respect them, regardless or whether we 'recognize' their
credentials? :-)

-Tommy Mac
-------------------------------------------------------------------------
Tom McWilliams 517-355-2178 wk   \ They communicated with the communists,
[e-mail] 336-9591 hm \ and pacified the pacifists. -TimBuk3
-------------------------------------------------------------------------

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

Date: Tue, 25 May 1993 00:22:47 GMT
From: Kazuo Yoshida NASDA/TKSC <[e-mail]>
Subject: LE-7 CAPTIVE FIRING TEST
Newsgroups: sci.space

                PRESS RELEASE

                LE-7 CAPTIVE FIRING TEST

                                              May  14, 1993
                            NASDA HQ, Tokyo

  National  Space  Development  Agency of Japan  (NASDA)  will  conduct
  the  second  series  of  the  captive  firing test of LE-7 engine for
  H-II  launch  vehicle  at  the Yoshinobu (H-II) Launch Complex, Osaki
  Range,   Tanegashima   Space   Center   (Address:   Minamitane-machi,
  Kumage-gun,  Kagoshima  891-37).   The  purposes  of the tests are to
  verify  the  level  of  integrated  performance  of  the  first-stage
  propulsion  system  and  to  confirm the interface between the first-
  stage  propulsion  system  and  the  ground support facilities at the
  launch complex.

  Schedule:    DATE           Firing Duration
            ---------------       ---------------------
         May  20, 1993          20 seconds
         May  31, 1993       100 seconds
         June 15, 1993       full duration
         June 29, 1993       (depend on June 15)

  Each  ignition  time  is  scheduled  at  around 2:00 PM. The date and
  time  are  subject  to  change  due  to  the weather condition and/or
  unexpected reasons.

  If  you  are  interested  in  covering  the  each firing test, please
  contact below.

         ****************************************************

  For  further  information,  please  contact  the  following:
  Yoko  Inomata,  Akiko  Suzuki/NASDA  Public  Relations  Office, Tokyo
  Phone: [phone],  Fax: [phone],  [e-mail]

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

Date: Mon, 24 May 1993 20:57:31 GMT
From: mark pitcher 9208 U <[e-mail]>
Subject: Looking for rocketry software...
Newsgroups: sci.space

    A few years ago, I put together a simple program to help me
determine what characteristics to expect from amateur rockets. By entering
details about burn rates, nozzle configurations, etc., I was able to
determine (usually within about 10%) the probable flight characteristics of
the amateur rockets.  I tested this program with data from sounding rockets
(Nike Apache, Judi-Dart, Metroc, HAD, Emma, and a few others) and got about
5% error.

    A few weeks ago, I found some more specific literature, regained
interest in the computer program, and put together a "Microsoft Windows"
application that not only gives the flight characteristics, but draws graphs
of the flight and gives "ideal" dimensions for casing sizes, nozzle shapes,
etc.

    I have since found even more detailed information on rocket flight
characteristics, and am putting together an even more elaborate program.
With the information I have now, I _should_ be able to calculate not only
the basic characteristics, but figure out how to orbit a payload on the
rocket (which is the ultimate goal of us all, isn't it?)

    I am looking for other such computer programs that I can use as a
guide, or to compare my results with.  If you know of such a program, please
email me and tell me where I can find it.  Thanks.


--
--------------------------------------------------Wilfrid Laurier University
[e-mail] (Mark A. Pitcher)
----------------------------------------------------------------------------
"Good...Bad... I'm the one with the gun..."

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

Date: 24 May 93 22:34:51 GMT
From: Tom Zych <[e-mail]>
Subject: Moon Base
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>I've been on the other side of this with Nick, but comets and Earth
>crossing asteroids may offer much higher commercial rewards. And
>open space offers commercial potential for communications, manufacturing,
>and perhaps even power. What's Luna offer? Maybe He3, some light metals
>and oxygen buried in yet another gravity well. Not very appealing.

First of all, unlike comets & asteroids, the moon is not going
anywhere.  Any other body large enough to be worth exploiting
would require enormous delta-v to decelerate into earth orbit.
As for orbital facilities, yes, they will be very valuable.  Where
are you going to get the raw materials?  Hauling them up from Earth
would be much more expensive than getting them on the moon.
Energy cost is less than 5% of launch from Earth, and a mass
driver can be used there, obviating any use of reaction mass
until capture.

>... I suggest we forget the dead
>Moon, and like the pioneers crossing the western deserts to reach
>the California gold fields, head for the most promising targets
>first and let the desert rats comb the rest at leisure. Lunar
>bases don't make economic or scientific sense, and they aren't
>*necessary* stepping stones to the more interesting targets.

Necessary, no.  Economical and conducive to expanded programs, yes.
--
Tom Zych
[e-mail]

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

Date: Mon, 24 May 93 21:22:00 EDT
From: Tom <[e-mail]>
Subject: Moon vs. asteroids, Mars, comets

Henry Spencer sez;
>Commercial justification for a return to the Moon is slim, but for
>anything else -- Mars, asteroids, etc. -- it's nil.

Ooh, boy, I may be going out on a limb, taking issue with Henry... :-)

But this seems a little premature.  Near-earth asteroids are, energy-wise,
quite easy to get to, comets and asteroids are almost completely unkown,
WRT to materials, but we expect them to contain many valuable materials
for industry, life-processes, and space-faring in general.  I'm thinking
of volatiles, methane, water, etc., and metals.

It seems there would be a large commercial justification in finding out
what they actually are made of, since if our expectations are correct,
they would make valuable targets for further exploration and/or exploitation.

We've flown by 2 comets, and 1 asteroid, soon to see another up close. But
the only analysis has been spectral, if I remember correctly. No penetrators
or sample returns that could tell us how valuable these things actually are.

-Tommy Mac
-------------------------------------------------------------------------
Tom McWilliams 517-355-2178 wk   \ They communicated with the communists,
[e-mail] 336-9591 hm \ and pacified the pacifists. -TimBuk3
-------------------------------------------------------------------------

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

Date: 24 May 1993 23:55:10 GMT
From: "Chris W. Johnson" <[e-mail]>
Subject: New DC-X GIF
Newsgroups: sci.space

In article <[e-mail]> Andy Cohen,
[e-mail] writes:
> A new DC-X photo will be available very shortly on
> bongo.cc.utexas.edu....pub/Delta Clipper
>
> The photo is of DC-X on the static firing test platform.....DCXSnds.gif

That photo has now been made available (thanks again Andy). Also available
is a good picture from the rollout taken by a friend who was nice enough
to have it developed on a Photo CD and mailed to me (so if anyone wants
the 3000x2000 version, just let me know :-).

Anyway, the new images are as follows:

    pub/delta-clipper/images:
    dcx-static-test-rig.gif
    dcx-rollout.gif
    dcx-rollout.jpg

...and they're located on bongo.cc.utexas.edu (128.83.186.13) as usual.

BTW, if, during the last two weeks, there were any DC-related postings
that should be archived, please send 'em along. I was out of town on
business.

----Chris

Chris W. Johnson

Internet:   [e-mail]
UUCP:       {husc6|uunet}!cs.utexas.edu!ut-emx!chrisj

...wishing the Delta Clipper team success in the upcoming DC-X flight tests.

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

Date: Mon, 24 May 1993 23:02:06 GMT
From: Josh Hopkins <[e-mail]>
Subject: Pros and cons of the Moon
Newsgroups: sci.space

The following discussion is about whether space based civilization will be on
the Moon or in free space.  I want too point out that I'm not favoring one
over the other - it's not an either/ or question.

[e-mail] (Gary Coffman) writes:  stuff with one >
>Nick Janow writes:            stuff with >>
>>Gary Coffman writes:            stuff with >>>
>>
>>The moon offers easily available metal and oxygen ores and a gravitational
>>field, and is nearby (short communication times and within manned reach).  It
>>would probably be cheaper and easier to develop a resource extraction
>>facility there than to develop zero-g facilities for extracting water from
>>near-Earth asteroids.

>Perhaps not. To mention only a couple of free space advantages, continous
>solar power and relatively easy availability of any desired temperature.
>The temperature extremes on the surface are much higher than on Earth
>or in free space on a thermally controlled platform. It's nearly trivial
>to keep any desired temperature by use of paints and rotation in space.

It's not hard to control temperature on the Moon either.  Passive shading allows
temperatures as low as 40 K.  The Moon also offers a massive heat sink.

>The *lack* of a gravity well simplifies large structures and reduces the
>energy requirements for materials handling.

The structures issue is not obvious to me.  1/6 G does not cause enormous
structural requirements.  On the other hand, it does limit vibrations problems
and gives a massive body for moments to act against.

>There are some emergency scenarios where a three day transit time is
>less of a problem than a 6 month transit time, but most situations
>would require either immediate help or don't bother.

On the other hand, day to day issues in industry do depend on interaction with
multiple sources.  If you need spare parts, on site experts or other imported
products, it may be difficult to run a business where those choices have to be
made a few months in advance (assuming the comparison is deep space activity,
not cis-lunar).

>>The technology and facilities developed with a lunar base project would
>>greatly reduce the cost of developing open-space projects.  It would be a
>>more gradual development; technology in small steps, rather than one risky
>>leap.

>Are we sure of this? None of the material transport systems developed would be
>useful in open space. Few of the radiation protection or thermal shielding
>techniques would translate. Most of the processes would be totally different
>because of the gravity well and differences in ores. For men on site, even
>the spacesuit designs would be radically different. Even 1/6 G changes the
>best manner of locomotion grossly. You can't really "walk" in space despite
>the popular media's phrasing.

I agree that the technology would be different. However, for all the examples
you cite, working on the Moon is _easier_ than free space.

>Luna would offer the additional complication of dust being
>tracked into the habitat every time someone or something is moved through
>a lock.

I agree with this one.

>>>Lunar bases don't make economic or
>>> scientific sense, and they aren't *necessary* stepping stones to the more
>>> interesting targets.
>>
>>They aren't *necessary*, but they could make economic and scientific sense.

>The only real scientific mission of value to Luna would be a radio observatory
>on the farside where the sensitive receivers could be shielded effectively
>from the radio noise of Earth. Optical observatories are probably better
>placed in open space because of the microscopic distortions introduced by
>the Lunar gravity field, though there is something to be said for a large
>inactive anchor point. That would be disturbed by lunar mining and blasting,
>so the two are unlikely to coexist happily.

There are benefits to be found on the Moon for all types of astronomy, from
plain old ordinary optical stuff to gravity wave telescopes.

Tiny gravitational distortions and human vibrations are far outweighed by
what is otherwise a very stable surface.  Lunar siesmic activity is about 100
millionth that present on Earth.  This stability is available over a huge area
with effort necessary by the hardware.  This contrasts greatly with the troubles
space based observatories have with vibration, short orbital periods and active
pointing and stability.  People are already proposing optical interferometers
and gravity wave detectors spread out over kilometers.  It's _very_ hard to
do that in free space.

The Moon also offers benefits in atmosphere (the density is lower than in LEO),
and resources.  Lunar bases and observatories can use everything from simple
terrain or regolith to local materials like oxygen, glasses and cements.

--
Josh Hopkins                                          [e-mail]
    "This Universe never did make sense; I suspect it was built on
              government contract."
                -RAH

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

Date: Mon, 24 May 1993 22:49:02 GMT
From: Dave Michelson <[e-mail]>
Subject: Soyuz and Shuttle Comparisons
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Chris Jones) writes:
>
>>Note that the Soyuz-derived Zond *was* launched by a Proton (SL-12).  This
>>may be the source of the confusion.
>
>I thought it was the SL-13, but I don't have a reference here.  Can anyone
>support or correct the following:
>
>Proton 2 stage       SL-9       D
>Proton 3 stage       SL-12      D1
>Proton 4 stage       SL-13      D1e

According to Clark (The Soviet Manned Space Program), Zond 4--8 were
launched using the four stage SL-12 variant and Salyut/Mir were launched
using the three stage SL-13 variant.

The two-stage Proton (SL-9) flew four times (and failed once) in 1965-66.

The four-stage Proton (SL-12) is the one that the Russians have been trying
to sell to the West as a launcher for geostationary satellites.

--
Dave Michelson  --  [e-mail]  --  University of British Columbia

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

End of Space Digest Volume 16 : Issue 624
------------------------------