Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_3/V15NO383.TXT

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Date: Fri,  6 Nov 92 05:00:05
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #383
To: Space Digest Readers
Precedence: bulk


Space Digest                Fri,  6 Nov 92       Volume 15 : Issue 383

Today's Topics:
                           Comet Collision
                     Drop nuc waste into (2 msgs)
                     Duncan Steel on Swift-Tuttle
                        getting hit by a comet
                          Light sails again
                           Man in space ...
                          Man in space ... )
                        NASA Coverup (4 msgs)
              NASA Coverup - doing backflips on the Moon
                    Putting volatiles on the moon
                      Russian Engines for DC-Y?
                   Scenario of comet hitting Earth
                        the Happyface on Mars
                        The Spaceguard Survey

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

Date: 5 Nov 92 03:45:52 GMT
From: Steve Linton <[e-mail]>
Subject: Comet Collision
Newsgroups: sci.space,alt.sci.planetary

In article <[e-mail]>, [e-mail] (Wayne Harvey) writes:
|>
|> >In <[e-mail]> [e-mail] (John Black) writes:
|>
|> >>Maybe a near comet approach could be a good thing. I did a rough calculation
|> >>and estimated that there must be something of the order of 10 to the power 11
|> >>metric tonnes of water. Maybe in 130 years time somewhere on the Earth could
|> >>do with some water,  <et cetera>
|>
|> Here's something that people seem to be missing, that has been bandied about
|> by SF writers for a long time: 10^11 tonnes of water (and associated other
|> shit), if we could capture it and place it in Earth orbit, would provide
|> us with an awful lot of fuel for rockets. Perhaps we could even have fusion
|> rockets when the comet comes back in 130 years, and that would make for
|> some pretty inexpensive colonisation fuels.

The delta-v needed to place P/S-T in Earth rorbit is several times (5) more than that
needed to lift water or ice from the Earth's surface to orbit. Superficially this seems
to rule out the sort of scheme you propose, but there are other considerations.

The delta-v requirement can be greatly reduced by steering the comet at aphelion rather
than close to the Earth. This can't get it into an Earth orbital trajectory, but it coul;d
arrange an encounter with Jupiter or Saturn that might do something useful

Alternatively, close to the Sun there are forms of thrust available for maneuvering
comets that are not available for lifting  water from the Earth. Nuclear explosives to
create artificial outgassing, for example, or sunshades to control natural outgassing.
Again a direct Earth capture is unlikely, but a Jupiter assist might be achievable.

Finally, we could collide the comet, using one of the above tricks, with  something and
stop it that way. The Moon is one possibility, an Earth-crossing asteroid might be
another.

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

Date: Wed, 04 Nov 92 16:03:00 PDT
From: Lauren Podolak <[e-mail]>
Subject: Drop nuc waste into
Newsgroups: sci.space

DD>Since the earth's escape velocity from near the surface is 11 km/s, a
DD>payload on a direct solar impact trajectory would have to be moving at
DD>about sqrt(11^2 + 30^2) = 32 km/s at thrust termination.  However,
DD>a payload on a solar escape trajectory would need a speed of only about
DD>sqrt(11^2 + 12^2) = 16 km/s.  Since energy is proportional to v^2, the
DD>direct solar impact trajectory takes about 4 times the launch energy as
DD>the solar escape trajectory.  This is a HUGE difference.

Why not simply dump the stuff on Luna?  Less energy involved yet and
frankly it makes sense since at some date we will probably come up with
a need for the stuff.

Lauren
___
 X OLX 2.1 TD X Who said that Interstellar Empires don't exit?

--
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      For information write to [e-mail]

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

Date: Wed, 04 Nov 92 16:03:02 PDT
From: Lauren Podolak <[e-mail]>
Subject: Drop nuc waste into
Newsgroups: sci.space

HS>Actually, as Larry Niven pointed out, if you can get the stuff as far as
HS>Venus, you might as well just fly it *into* Venus.  It's not as if Venus
HS>is good for anything else.  (Although one would want to do rather more
HS>thorough studies of Venus before starting to use it as a dump...)


Why do that?  Conceivably Venusian terraforming could be done and now
you've contaminated it with radioactives.  If dumping is the solution
dump on an airless body.

Lauren
___
 X OLX 2.1 TD X Unable to locate Coca Cola -- Operator Halted!

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      For information write to [e-mail]

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

Date: 5 Nov 92 01:20:13 GMT
From: Jeff Bytof <[e-mail]>
Subject: Duncan Steel on Swift-Tuttle
Newsgroups: sci.space,sci.astro

>(3)  There has been a lot of bull written in these columns about
>   P/Swift-Tuttle and whether it will hit the Earth and what the
>   consequences might be.

How true.  I have not yet seen ONE independent confirmation of
the orbital calculations and a sober error analysis.  For all we
know, this could be somebody's mistake.

---------------------------------
Jeff Bytof
[e-mail]

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

Date: Thu, 05 Nov 1992 05:19:46 GMT
From: David Messer <[e-mail]>
Subject: getting hit by a comet
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Mal Logan) writes:
 >I personally couldn't think of a better way to get rid of all our nukes - aim
 >it at the comet -

Right.  Then we get hit by a radioactive comet.  Some improvement. :)
--
It's not my fault!                   | David Messer       [e-mail] -or-
    I voted for Andre Marrou.        | Lynx Data Systems  ..!tcnet!lynxds!dave

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

Date: 5 Nov 92 08:59:14 GMT
From: Magnus Olsson <[e-mail]>
Subject: Light sails again
Newsgroups: sci.space

In article <ida.720921989@atomic> ida@atomic (David Goldschmidt) writes:
>  A light sail works by light pressure (I calculate F = Power/C,=
>4.66 E -6 /m^2 at 1 AU)  My question comes from what happens if you tilt
>the sail.  It will red or blue shift the light just as much as a nontilted
>sail, so the force on it should be the same, but is it applied in the same
>direction as the light, or perpendicular to the sail?
>   force            force
>     | /               \  /
>     |/         or      \/________>  light path
>     /_____>            /|
>    /|                 / |
>   / | <light         /  |
>  ^mirror            ^mirror
>
>  If possible could somebody explain why it happens whichever way.  Its not
>clear to me why the energy lost or gained in red or blue shifting the light
>has to go into kinetic energy  (couldn't it just heat up the sail?)


This is not intended as a flame, but I think you need to take a deeper
look at your freshman physics course.

What's important isn't just energy conservation, but momentum
conservation. Light carries momentum (the simplest way to understand
this is to think of a light beam as a stream of particles, photons,
but it works for waves as well), and when you deflect a light beam you
change its momentum. This change has to be compensated in some way -
if the mirror is free to move (as is a light sail), it will take up
the missing momentum by starting to move.

This is exactly as if you were to bounce a lot of tennis balls off the
mirror.


In your example, light comes in in the upward direction and goes out
to the right. This means its total momentum change is directed
downwards to the right (at 45 degrees in your picture). The light sail
will compensate this by moving in the opposite direction. This means
it will feel a force that is directed upwards to the left, at a 45
degree angle.

So, to answer your question shortly, it's momentum conservation that
prevents the absorbed energy from just heating the mirror.


Magnus Olsson                   | \e+      /_
Dept. of Theoretical Physics    |  \  Z   / q
University of Lund, Sweden      |   >----<
Internet: [e-mail]     |  /      \===== g
Bitnet: THEPMO@SELDC52          | /e-      \q

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

Date: 5 Nov 92 06:26:50 GMT
From: Eric Goldstein <[e-mail]>
Subject: Man in space ...
Newsgroups: sci.space

I showed the guy down the hall the FAQ on "How Long Can A Human Live
Unprotected In Space" and he sent me the following response, which he
agreed to let me post.

----------------Letter-From-Eric-Shafto---------------------------------------

>    HOW LONG CAN A HUMAN LIVE UNPROTECTED IN SPACE
>
>    If you *don't* try to hold your breath, exposure to space for half a
>    minute or so is unlikely to produce permanent injury. Holding your
>    breath is likely to damage your lungs, something scuba divers have to
>    watch out for when ascending, and you'll have eardrum trouble if your
>    Eustachian tubes are badly plugged up, but theory predicts -- and animal
>    experiments confirm -- that otherwise, exposure to vacuum causes no
>    immediate injury. You do not explode. Your blood does not boil. You do
>    not freeze. You do not instantly lose consciousness.
>
>    Various minor problems (sunburn, possibly "the bends", certainly some
>    [mild, reversible, painless] swelling of skin and underlying tissue)
>    start after ten seconds or so. At some point you lose consciousness from
>    lack of oxygen. Injuries accumulate. After perhaps one or two minutes,
>    you're dying. The limits are not really known.

I vividly remember a NASA publication entitled "14 seconds of useful
consciousness."  The claim was that, in case of rapid decompression, a
human had 14 seconds to fasten a helmet, close a door, throw a switch, or
whatever.  Not that you were seriously injured in that time, but you would
be incapable of taking whatever actions were necessary to save your life
after 14 seconds.

I wish this article had talked more about that.

As for injuries, while your blood would not boil (at least not for a very
long time) I would think that the fluids in your lungs certainly would.
This should mean two things, I would think.  One is that I was wrong in
saying that, in a vacuum, you could close your mouth and nose and still
move your chest as though you were breathing.  The boiling mucus should
build up a decent pressure in your lungs and prevent you from doing that.
In fact, I would imagine that gas would continue to escape from your lungs
the entire time you were in the vacuum*.  The second implication is that
your lungs should get very, very cold, below 0 degrees C, anyway.  You
might survive your exposure, only to asphyxiate after your return to a
pressurized environment, due to frostbite of the lungs.

*Well, for the first few hours, anyway.  After that, I think you would tend
to emit a plume of gas and particles around perihelion.

***************************************************************************
* Eric Shafto              * Man, unlike any other thing ... in the       *
* Institute for the        * universe, grows beyond his work, walks up the*
*    Learning Sciences     * stairs of his concepts, emerges ahead of his *
* Northwestern University  * accomplishments.  -John Steinbeck            *
***************************************************************************

------------------End-of-Letter---------------------------------------------

Comments anyone?

Has anyone else seen the NASA publication?

What does happen to the liquid in the lungs?  And ignoring the joke
about the spacefarer looking like a comet, is Eric Shafto wrong about
the danger of freezing?

      -- Eric Goldstein

--

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

Date: 5 Nov 92 04:43:13 GMT
From: Andrew Haveland-Robinson <[e-mail]>
Subject: Man in space ... )
Newsgroups: sci.space

In article <[e-mail]> you write:

>In article <[e-mail]>, [e-mail] (Andrew> Haveland-Robinson) writes:
>>
>> In article <[e-mail]> [e-mail] writes:
>>>   What will happen if the space suite of an austronaut gets ripped in space> ?
>>
>> Well Nick, my feeling is that he would nearly explode.
>
>*Bzzt* Wrong, but thank you for playing.  I append Henry Spencer's
>summary of this every-so-Frequently Asked Question from the FAQ files
>(as if they hadn't been posted just days ago!).
>
>Ever put your hand up against the nozzle of vacuum cleaner? Your skin
>will hold about 1 atmosphere pressure nicely.
>
>The reason I'm writing, instead of just allowing the discussion to
>peter out, is to mention that a suggestion of Hermann Oberth's:
>Astronauts might wear spacesuits without gloves for delicate work!

!!

Ah well... I stand corrected...  Thanks for the explanation, it still
sounds like a horrible way to go...

I suppose after further thought, if one doesn't notice the 7psi or so at
35,000ft in an aircraft, 0 psi isn't going to make that much difference.

The key is the uniformity of pressure - a vacuum cleaner could cause a
slight bruise in time, but that's because of the 15 psi air pressure trying
to squeeze you into the tube!  Reduce the outside pressure, and reduce the
apparent suction.

One problem is the density of air at low pressures for breathing.
I'm sure that an acclimatisation programme would help too.

I would guess that space suits and space biosphere pressures are
substantially less than trophospheric pressure ~ 5 psi?

With an oxygen enriched supply, and spacesuits at 5psi, naked hands in space
should be quite feasible.

Most interesting, thanks for putting me straight on that...

Andy.

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

Date: Wed, 4 Nov 1992 21:13:57 GMT
From: Bronis Vidugiris <[e-mail]>
Subject: NASA Coverup
Newsgroups: sci.physics,sci.space,alt.conspiracy

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

)   jump about 18 inches vertically without a  run.   On  all  of  the  video
)   footage  shot  by  the  astronauts  while  in  the moonwalking mode , the
)   highest leaps performed by the most vigorous individuals,  such  as  John
)   Young,  never  amounted  to  more  than  about 18 inches, while they were
)   THEORETICALLY CAPABLE OF SLOW BACKFLIPS!

If we assume, though, that the moon landings *were* real and in low G (just
for the purposes of argument, of course), wouldn't it be plausible that the
astronauts were being very careful and restrained *NOT* to do backflips, in
ordor to avoid possible adverse effects due to a bad landing damaging their
space suits?

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

Date: 5 Nov 92 01:19:19 GMT
From: Ian Matthew Burrell <[e-mail]>
Subject: NASA Coverup
Newsgroups: sci.space

This post will attempt to completely destroy the allegation that the
government is hiding some undefined fact about the Moon's mass or density.
For, if what a you say is true, the Moon must have much different mass
than accepted.

First some numbers:
Mass of the Earth: 5.98 x 10^24 kg
Radius of Earth: 6.37 x 10^6 m or 6370 km
Mass of Moon: 7.34 x 10^22 kg
Radius of Moon: 1.74 x 10^6 m or 1740 km
Distance from Moon to Earth: 3.84 x 10^8 m or 384,000 km

Using the equation from Newton's Law of Gravitation, a = (G*M)/R^2, the
acceleration due to gravity at the Earth's surface is 9.8 m/s^2 (1G) which
is a undeniable physical fact.  The acceleration at the Moon's surface is
1.62 m/s^2 which is approximately 0.165 G or 1/6 G.  The barycenter, the
point which the Earth and Moon revolve around is the center of mass of the
system.  It is (m*d)/(M+m) from the center of the Earth.  That is 4656 km
from the center of the Earth, or almost 380,000 km from the center of the
Moon.  The barycenter  is well inside the Earth.  However, the Earth-Moon
system does have a noticeable wobble to it since the masses are so close
inside.  Neglecting rotation, etc., the point where the gravity from each
body cancels, is solved by setting the forces equal and solving.  I found
that the "neutral" point (which has little meaning in the real rotating
system) is roughly the same distance from the center of the Moon as the
center of mass is from the Earth's center.  However, this calculation is
fairly complicated and my answer is suspect.

BTW, the density of the Earth is 5523 kg/m^3 (or 5.52 g/cm^3, about five
times the density of water).  The density of the Moon is 3308 kg/m^3 or
three times the density of water.  If we use your suspect value of the
gravity of the Moon's surface being .64G, then the mass of the Moon must
be 2.86 x 10^23 kg or one twentieth of the Earth's mass or four times the
Moon's present mass.  This would be manifested in a much different
barycenter for the Earth-Moon system.  The density of the Moon would be
twelve times the density of water, much heavier than rock or metal,
approaching the density of lead or gold.

The fact is, astronomers can determine the mass of the Moon using a
variety of techniques, which are extremely accurate and do not require
getting anywhere near the moon.  For example, astronomers can inaccurately
determine the mass of stars light years away!  The tides also offer a
qualitative reason why we can guess at the Moon's mass.  Also, there is a
large body of PUBLIC DOMAIN info. from the lunar "landers" and orbiters
which would prove the true value.  There are probably books with the
gravitational calculations and the info. on suits, acrobatics, and the
history of the failed probes.

The failure of the early lunar probes can be explained by inaccuracy in
measurements (navigation requires very high precision), possible neglect
of other factors such as the Earth and Sun's effects, bad equipment, or
many other problems that early missions had to work out.  Just a small
error at the beginning of the mission could result in a large discrepancy
at the end.  Something as basic as the Moon's mass or gravity cannot be
kept secret from anyone with a pad of paper, a telescope could figure it
out, and a desire to know.  Why would the U.S., Russia, Japan, most other
space-faring nations, and literally thousands of scientists and engineers
not in NASA but other public and private organizations keep this secret.
Scientists and engineers tend to be bad at keeping secrets, especially
this big and widespread.

The recent point of space suits and lack of athletic ability of lunar
astronauts is interesting but false.  First, astronauts were probably
prohibited from acrobatics because of the very high possibility of injury
(or death) if the fouled up in the clumsy suits and unfamiliar
environment.  Second, although the gravity is lower, the inertia is still
the same.  Third, those suits are unmaneuverable, and probably not
designed for any vertical leaping.  Movies/photos of lunar astronauts
showing them adopting a leaping gait, only possible on the Moon.   Also,
those old suits are heavy, just how heavy I don't know.


Finally, some minor flames: What exactly is NASA covering-up and why?

Ian Burrell

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

Date: Thu, 5 Nov 92 03:57:26 GMT
From: Laurence James Edwards <[e-mail]>
Subject: NASA Coverup
Newsgroups: sci.physics,sci.space,alt.conspiracy

In article <[e-mail]>, [e-mail] writes:
|> [....]
|> As to jumping in spacesuits on the moon, don't forget that those suits are
|> probably rather stiff.  Probably the jumps are quite poor compared to what
|> would be possible if they wore normal clothing with lead-filled backpacks
|> with the same mass as the suits.
|>
|> -Mike

self preservation may also be involved here ... if you take a giant leap
and fall on something sharp that punctures your spacesuit ...

by the way, this is all one long running joke, right?

Larry Edwards

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

Date: 4 Nov 92 22:05:33 GMT
From: [e-mail]
Subject: NASA Coverup
Newsgroups: sci.space

Why do people still kling to the notion that we didn't actually go to the moon?...

I'm sorry, but I have a real problem with that...

I know our government has done some really dirty things in the past, but I really think
that they wouldn't spend billions of dollars so that they could lie to us...

Think of it this way, they all pay taxes just like the rest of us, so why would they
want to throw they're money away so that they could lie to the American people.

The government is corrupt, no doubt about that...but I think that covering up a moon
mission is far beyond anything they could do..

As for snarfy's math arguments...I don't have time to sit down and work through them
myself...but I really don't think that 100's(?) of people (the ones doing the
calculations) could be persuaded to lie for this many years....

We went to the Moon....no doubts in my mind...

                James

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

Date: Thu, 5 Nov 1992 04:46:21 GMT
From: "Andrew P. Anselmo" <[e-mail]>
Subject: NASA Coverup - doing backflips on the Moon
Newsgroups: sci.physics,sci.space,alt.conspiracy

As I recall, one astronaut DID 'take a flying leap' at one point while
walking on the moon, and regretted it the second he took off.  He forgot
about all the weight on his back, and DID start to do a SLOW backflip,
and landed (partially)  on his backback.
The big thing that went through his mind was,"
Holy Shit! If I land on the backpack and BREAK something, I'm fucked..."

I paraphrase, of course.  But I recall reading this somewhere.  Those suits
are a bitch to move around in BTW.  I tried on just the GLOVES in my old
lab at Grumman, and it is VERY difficult to anything...

-A.


--
--------------------------------------------------------------------------------
 Andrew Anselmo / Department of Mechanical Engineering / Columbia University
          Thermal Science Research Laboratory (236A Mudd)
   220 SW Mudd Building 212-854-2965 / [e-mail]

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

Date: 5 Nov 92 03:43:23 GMT
From: Carl Hage <[e-mail]>
Subject: Putting volatiles on the moon
Newsgroups: sci.space

[e-mail] (Gary Coffman) writes:
: The AEC's Project Plowshare. Several civil engineering tests were done
: with nuclear explosives here in the US under this project. ...  Other
: projects, such as creating undergound storage caverns for natural gas,
: compressed air for electric peak shaving plants, and for oil storage
: were also explored. After an initial purge of loose radioactives, the
: caverns would be cheap and effective storage chambers for such light
: atoms since neutron activation is not an issue. Except for popular
: hysteria, those projects remain attractive today.

Correct me if I'm wrong. While visiting Los Alamos last year I asked about
the (only?) test, which was in Colorado and attempted to release natural
gas.  The experment was a failure because the residual radation levels did
not decline sufficiently, and the released gas was unusable. These
projects remain unattractive today due to radioactive contamination, not
hysteria.

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

Date: 5 Nov 92 05:59:45 GMT
From: "Robert B. Whitehurst" <[e-mail]>
Subject: Russian Engines for DC-Y?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Bruce Dunn) writes:
>> Brad Whitehurst writes:
>>
>>         Av. Week had a second article on the NPO RD-701, a tri-fuel
>> engined which burns kerosene, LOX, and LH2, with continuously variable
>> fuel transition from kerosene to LH2.  Is this to customize the rocket
>> performance as a function of altitude, load, etc.?  The thrust figures
>> for all kerosene were significantly higher than with pure LH2.
>
>
>        This makes the RD-701 a "tripropellant" engine.  Numerous design

    Oops, yes "tripropellant", not fuel.  Brain was not fully
engaged. :-)

>studies done in the US have shown that using a tripropellant engine can lower
>the dry mass of SSTO vehicle by a modest amount.  The engine uses mainly
>kerosene/LOX during the early part of the flight, when specific impulse is
>not so important, and thrust and propellant density is very important.  Later
>in the flight, the engine switches to LH2/LOX because specific impulse
>becomes more important than thrust level and propellant density.
>      The upper stages of multi-stage vehicles or the later parts of SSTO
>flights are critically dependant on specific impulse, because all the
>propellant for these sections of the flight has to be boosted to several
>thousand meters per second before use.  If a given lower stage can only boost
>say 100 tons of propellant to say 6000 meters per second, then it is far more
>useful to have 100 tons of LH2/LOX than 100 tons of kerosene/LOX at this
>velocity.  Propellant burned however at the beginning of a flight does not
>have to be boosted through any great velocity increment and its specific
>impulse therefore is not too important.  However for an SSTO vehicle, the
>tank for the early-burn propellant still has to be boosted all the way to
>orbit, therefore it pays to have a dense propellant combination.  In this
>case, kerosene/LOX wins over LH2/LOX.
>        The design studies generally show about a 20 to 25% reduction in dry
>mass by using a tripropellant engine in an SSTO.  However, this reduction
>comes at the price of a 50% increase in the number of propellant tanks,
>piping systems, valves, and turbopumps, as well as the need for a complicated
>combustion chamber and/or nozzle arrangement to handle the two fuels.  The
>Aerojet Corp. did a number of design studies on a "dual expander"
>propane/LH2/LOX engine, but to my knowledge never built such an engine.
>--
>Bruce Dunn    Vancouver, Canada   [e-mail]

    The interesting thing about this article was that it said that
the RD-701 used only two turbopumps, with the LOX and kerosene being
pumped by one, and the LH2 by the other.  I read it quickly, so I
might have this wrong, but that sounds rather intriguing.  Is
fuel/oxidizer premixed in other engines?  They said the kerosene could
be throttled back simultaneously with throttle up of the LH2.  Sounds
like a real trick to me!  I gotta go read it again tomorrow...
--

Brad Whitehurst    |   Aerospace Research Lab
[e-mail] |   We like it hot...and fast.

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

Date: Thu, 05 Nov 92 12:58:39 +1100
From: glenn durden <[e-mail]>
Subject: Scenario of comet hitting Earth
Newsgroups: alt.sci.planetary,sci.astro,sci.space

[e-mail] (John Black) writes:

> PS no-one answered my question about what the "P/" means infront of comet nam

It stands for 'Periodic'.
This is just an indicator that the comet is in orbit around the sun and comes
back every so often.    (as opposed to non-periodic comets which are either
just passing by the sun once only..ever, or that the comets orbit is so large
that to all intents and purposes it might as well be non-periodic)

.........................................................
glenn durden
[e-mail]  Unique Computing Pty Ltd, Melbourne, Australia
The opinions expressed above are that of the author only.

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

Date: 5 Nov 1992 05:05:51 GMT
From: David Bell <dcb@mulka>
Subject: the Happyface on Mars
Newsgroups: sci.space,sci.astro

[e-mail] (Doug S. Caprette Bldg. 28 W191 x3892) writes:
: In article <[e-mail]> [e-mail] (Ed McCreary) writes:
: >Well, I'm happy, I received my Mars CDROMs in just the other
: >day.  I like to find the images that show the "Happyface" on
: >mars and the Kermit the Frog.  If anyone has either the Lat/Long.
: >or the image id of the pics, I'd appreciate hearing from you.
: >
: >I've got the both the raw and the MDIM sets.
: >
: 35A72 and 70A13
:
: 86A10
:
: 4A50, 4A51, 4A52, 4A53, and 4A54
:
: 775A10 and 775A11  or
: 77A10 and 77A11  (one is probably a misprint)
:
    Stuff Deleated.... (inbetween as well)

The Image Numbers with the A in them represent the Viking 1 Orbiter Primary Imaging mission.
The Cdroms that you have are from the Survey Mission and therefore all have an S in the image
numbers. The best way to find the images that you are looking for is to look at the MDIM
disks and using a suitable search utility look at the files "label.tab" in the index directory
on the disks. Each map image was taken from a collection of Raw Images and each label has
the raw images listed. So just search through the file using the string that you want and that
will enable you to find a MDIM image of the feature that you want. Check to see what other
images are listed along side and there may be a raw Image that you have on the Survey disks as well.
    I have tried this myself and have had some success but not overall success, since
some of the images refered to don't seem to be used in the MDIM Images.
All the cataloging data is also explained on the disks, I also believe that Dbase can be
used as well, since there are files that support it on disk.

    Warm Regards,
    David

    [e-mail]
    School of Physics, The University of Melbourne, AUSTRALIA

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

Date: Thu, 5 Nov 92 12:29:23 GMT
From: Joe Cain <[e-mail]>
Subject: The Spaceguard Survey
Newsgroups: sci.astro,alt.sci.planetary,sci.space

In article <[e-mail]> [e-mail] writes:
>For those of you who want some good background material about potential
>Earth-impactors, please refer to:
>
>    The Spaceguard Survey
>    Report of the NASA International Near-Earth-Objecat Detection Workshop
>    David Morris,  Chair
>    January 25, 1992

This report has been printed only in a very limited number of copies.
It might help to make them more available by writing to NASA
Headquarters, Washington DC 20546 and request that copies be made
available. I was able to obtain two for my planetary geology class
from committee members, but they indicated their personal supply was
about gone and there was no other source.

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End of Space Digest Volume 15 : Issue 383
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