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Subject: SPACE Digest V12 #453

SPACE Digest                                     Volume 12 : Issue 453

Today's Topics:
 1990 Antarctic ozone hole equals lowest previous levels (Forwarded)
     Re: Deep Space Network use (Was: Ulysses Update - 10/06/90)
           Re: disposal of N-waste into sun
            Re: N-waste sea water dilution
     Re: Deep Space Network use (Was: Ulysses Update - 10/06/90)
              Orbital elements bulletin
              Neural networks and robots
            Re: Magellan Update - 10/09/90
           Flames in 0g and Venusian dunes
                Teleoperations

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

Date: 12 Oct 90 23:42:34 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: 1990 Antarctic ozone hole equals lowest previous levels (Forwarded)

Brian Dunbar
Headquarters, Washington, D.C.                   October 11, 1990
(Phone:  [phone])

Dolores Beasley
Goddard Space Flight Center, Greenbelt, Md.
(Phone:  [phone])


RELEASE:  90-137

1990 ANTARCTIC OZONE HOLE EQUALS LOWEST PREVIOUS LEVELS


     Preliminary data indicate that depletion of stratospheric
ozone over Antarctica is matching levels observed in 1987 and
1989, the lowest ozone years recorded, NASA scientists said.

     Research by Dr. Arlin Krueger, Dr. Mark Schoeberl and Dr.
Richard Stolarski of NASA's Goddard Space Flight Center,
Greenbelt, Md., indicates the Antarctic "ozone hole" began
developing in the last week of August when the normal, winter
polar ozone levels started decreasing.  This was about one week
earlier than the beginning of depletion in 1987 and 1989, though
the timing of the start of the depletion has shown significant
variability over the years.

     Ozone, a molecule made up of three atoms of oxygen,
comprises a thin layer of the upper atmosphere that acts as a
shield against harmful ultraviolet radiation from the Sun.  In
the presence of sunlight, atoms of chlorine and other chemicals
can strip an oxygen atom from an ozone molecule, leaving behind
an oxygen molecule, which does not absorb the radiation.  Because
of the catalytic nature of the reactions, each chlorine atom can
destroy thousands of ozone molecules.

     The ozone hole is a large area of intense ozone depletion
over the Antarctic continent that typically occurs between late
August and early October.  The ozone hole has been monitored
since 1979 using the Total Ozone Mapping Spectrometer (TOMS), an
instrument on the Goddard-managed NIMBUS-7 spacecraft.

     Not only has the 1990 ozone hole matched the lowest levels
previously observed, but ozone levels throughout the Southern
Hemisphere has been as low as any previously recorded year.
Scientists have observed previously that the ozone hole has
followed a roughly biennial cycle, in which ozone depletion has
been less severe in even-numbered years than in odd-numbered
years.  The implications of such severe depletion in 1990 are
uncertain, said Dr. Robert Watson, Chief of NASA's Upper
Atmosphere Research/Tropospheric Chemistry Branch.  Year-to-year
variability in ozone depletion appears to be related to the
interplay of meteorological conditions and atmospheric chemistry,
but the exact process is not definitively understood by
scientists.

     NASA's programs for studying ozone depletion, managed by the
Office of Space Science and Applications, will expand in 1991
with the launch of another TOMS instrument aboard a Soviet Meteor
Satellite and the deployment of the Upper Atmosphere Research
Satellite by the Space Shuttle.  The just completed Space Shuttle
mission, STS-41, carried the Shuttle Solar Backscatter
Ultraviolet instrument (SSBUV), a device similar to TOMS that
estimates ozone levels by measuring reflected ultraviolet
light.  SSBUV collects data that are used to calibrate the TOMS
instrument.

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

Date: 12 Oct 90 07:07:33 GMT
From: wuarchive!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!watserv1!maytag!watcsc![e-mail]  (Trevor Green)
Subject: Re: Deep Space Network use (Was: Ulysses Update - 10/06/90)

[e-mail] (Jim Barnes) writes:
>If Ulysses needs 8 hours per day of coverage, Magellan is returning radar
>images several times a day, and Galileo is doing some interesting things
>at the same time, are there enough minutes in the day?  Will we just
>ignore the Voyagers/Pioneers/etc. for a while?  How much extra bandwidth
>does the DSN have?

Well, for starters, DSN has 72 hours per day.  The three receivers
(Madrid, Canberra and West Virginia(?)) each operate continuously
except for maintenance and power failures.

Trevor Green
They should set one up in Hawaii...

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

Date: Fri, 12 Oct 90 11:10 EST
From: 12-Oct-1990 1054 <[e-mail]>
Subject: Re: disposal of N-waste into sun
X-Envelope-To: [e-mail]

    In article <[e-mail]> [e-mail] (Dave Dodson)
    writes:
    >In article <[e-mail]>
    [e-mail] (Henr
    >>In article <[e-mail]>
    [e-mail]
    >>>Why would it be harder to send something to the sun than away from
    the sun?
    >>
    >>The direction is unimportant; what matters is the velocity change
    needed.

    ====

    Actually, there is no need to get n-waste into the sun, just get in
    into a solar orbit that cannot intersect earth orbit.  Both the
    earth and the waste orbits will eventually decay, but so will
    the n-waste radioactivity.  Giving it just a little bit of velocity
    beyond that needed to escape earth's gravity well (and retrograde)
    will be enough to ensure that it is never a hazard on earth.

    On the other hand, this still involves *launching* it from earth.
    That is inherently too risky to do on a large scale with dangerous
    waste products.  Putting 50 or 100 pounds of plutonium into a
    carefully sealed canister on a space probe is nothing compared with
    launching hundreds or thousands of *tons* of n-waste.  Perhaps more.
    Remember that the concrete inside a nuke becomes radioactive,
    and so the entire core must eventually be disposed of as n-waste.

    Given this you also can ask if there would be a net energy gain in
    using nuclear power and disposing of the waste this way.  What
    is the energy output of a pound of enriched uranium, and how does
    this compare with the energy *cost* of putting a pound of
    delpleted uranium into low solar orbit?  If the first number is
    lower than the second then this method of disposal is not
    scientifically possible to make economically feasible.

    Chris Eliot
    Umass/Amherst

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

Date: 12 Oct 90 21:21:38 GMT
From: voder!dtg.nsc.com![e-mail]  (L GENE BATTIN)
Subject: Re: N-waste sea water dilution

In article <[e-mail]>, [e-mail] (Alan Hepburn) writes...
~In article <[e-mail]> [e-mail] (Michael Hermann) writes:
~+In article <[e-mail]> [e-mail] (Alan Hepburn) writes:
~+>Picture this:  a supertanker modified slightly so that the nuclear
~+>waste starts out in the bow tank, being diluted 100:1 with sea water.
~+>This mix is then pumped to the next tank where it is diluted 100:1 with
~+>sea water.  And so on till the last tank, which is pumped into the open
~+>ocean.  You would be unable to detect other than background radiation
~+>in the resulting water.
~+
~+Gee, that's such a good idea. We could even do the same thing on land.
~+Perhaps in the desert. Or normal garbage headed for the landfill. I'm sure
~+Mr. Hepburn wouldn't mind us using his local landfill site. Afterall, one
~+backyard is as good as another.
~+
~+I hope you were joking.
~+
~+|  Mike Hermann  | [e-mail] ..!uunet!ubc-cs!calgary!hermann
~+_Organized_ religion is like organized crime: it preys on peoples' weaknesses,
~+generates huge profits, and is nearly impossible to eradicate.
~+--
~+|  Mike Hermann  | [e-mail] ..!uunet!ubc-cs!calgary!hermann
~+_Organized_ religion is like organized crime: it preys on peoples' weaknesses,
~+generates huge profits, and is nearly impossible to eradicate.
~
~My point was that sufficient dilution would render the waste harmless.
~The human race is not creating radioactivity; it is merely concentrating
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
~that which is already here.
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^

    Wrong.  We create radioactivity here at the cyclotron all the time.
    All it takes is some hydrogen gas and a little electricity.
    Different sorts of reactions take place in nuclear reactors, but
    radiation is created there too.


    -Gene Battin,  venus@iucf

    *********************************************
    * My opinions have nothing whatsoever to do *
    * with my employer.  So there.              *
    *********************************************

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

Date: 13 Oct 90 01:02:41 GMT
From: unmvax!nmt.edu![e-mail]  (Daniel Briggs)
Subject: Re: Deep Space Network use (Was: Ulysses Update - 10/06/90)

In article <[e-mail]> [e-mail] (Perry G Ramsey)
writes:
>There is a big radiotelescope facility in W. Virginia which
>I guess could be used for this sort of work, but I bet the radio astronomers
>wouldn't be too happy about it being used on a regular basis.
>The VLA (Very Large Array) radiotelescope near Socorro, New Mexico
>was pressed into service for Voyager's Neptune pass.

Just a very minor quibble with that statment, Perry.  The VLA wasn't
exactly "pressed into service."  NASA *bought* our services, fair and
square.  It was basically a barter agreement on a megabuck scale.  I
believe that NASA went out of pocket by some $8M.  About half of that
went into equiping the VLA with the necessary receivers to pick up
Voyager.  After it was used for Voyager, we got to keep the equipment.
The X band receiver system is currently the most sensitive one that we
have, and is very useful for astronomical observations.  The other $4M
was perhaps even more important.  It basically went into maintainance,
backup systems, and other such safeguards.  While we probably don't
need *two* on-site backup diesel power generators, we now have them
and they are useful.  We sure wouldn't have bought them by ourselves.
NASA, of course, truly did *have* to have them.  Likewise the
lightning protection system and the new control computers.  The power
system overhaul, on the other hand, was desperately needed and we just
couldn't afford it on our own.  (It's a lot easier to get $$ to build
new telescopes than it is to maintain existing ones properly.  Crazy,
but that's the way it is.)

The bottom line is that the Neptune encounter was an absolute godsend
to the VLA.  We couldn't have been happier that it happened.  (And on
top of all these practical considerations, it was just plain fun to
take part in the encounter!)  I strongly suspect that NRAO would jump
at the chance to participate in such a collaboration again.  For their
part, NASA expressed great satisfaction with our performance.  They
got an extra 50% more pictures than they would have without us.  In
terms of data/buck, I think they got a deal too.  It was one of those
neat situations where everybody wins.

--
This is a shared guest account, please send replies to
[e-mail] (Internet)
Dan Briggs / NRAO / P.O. Box O / Socorro, NM / 87801  (U.S. Snail)

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

Date: 11 Oct 90 17:01:29 GMT
From: dsl.pitt.edu!pitt!nss![e-mail]  (Bev Freed)
Subject: Orbital elements bulletin

I miss Dr. Kelso's posting of orbital elements bulletins.  Has he
departed, or are those bulletins no longer available?


--- Opus-CBCS 1.13
 * Origin: NSS BBS - Ad Astra! [phone] *HST* (1:129/104.0)
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UUCP: ...!pitt!nss!freed
INTERNET: [e-mail]

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

Date:     Fri, 12 Oct 90 02:14 CDT
From: <[e-mail]>
Subject:  Neural networks and robots

Can anyone give me information on specific applications of neural-network
controlled robots in space? Also, where I might find papers on this
subject?

Thanks,
Cheryl A. Hoefelmeyer
bitnet::ch02079@swtexas
Southwest Texas State University

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

Date: 12 Oct 90 05:14:50 GMT
From: uc!cs.umn.edu!quest!orbit!pnet51![e-mail]  (S Schaper)
Subject: Re: Magellan Update - 10/09/90

>What is going to be done about getting the information missed in the 4 orbits
for wwhich there was no good data received?

A. "Here be Dragons"



:-)


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The necktie is a device of Mordor
ARPA: crash!orbit!pnet51![e-mail]
INET: [e-mail]

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

Date: 12 Oct 90 15:08:21 GMT
From: [e-mail]  (Sushil Louis)
Subject: Flames in 0g and Venusian dunes


    I heard on CNN that one of the experiments performed on
Discovery was on the effects of 0g on flames. Anyone know what was observed
and if it was compatible with what was discussed here recently?

    Second: What exactly are these "sand dunes" mapped by Magellan
recently? Is the term "sand dunes" correct or is it something made up for
the media? Any Info or theories on this?

Sushil Louis
[e-mail]

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

Date:    Fri, 12 Oct 1990 10:45:49 CDT
From: [e-mail] (Austin)
Subject: Teleoperations
X-Vmsmail-To: SMTP%"[e-mail]"


Minsky wrote " Just do tele-remote operations at reduced speed"

Others wrote " Nah. What if the robot falls in a hole?  "

    Minsky is right on this one. If you think about your whole life,
you see it is based on delayed-time loops. Touch something hot and you will
see. The fact of your burn is proof of your delayed-time loop between sense
 decision then action. We do it while driving - even to the point of
anticipating another car's location and acting even before the car has shifted
lanes or has not shifted lanes, or has stopped at a sign or is pulling away
froma  light that has turned green. We'll open the refrigerator, grab what we
want, then tap the door with a foot to shut it; all in one smooth chain of
movements. The longer the amount of time to accomplish something, the more
simulation we do before and during our actions. Imagine you want to shoot
down a bear bomber, but you are five miles away and he is right underneath a
cloud deck. You have only guns and dont want to chase him into the clouds where
he could change velocity, and you don't want him screaming his head off anf you
dont want your radar to be picked up. So, you match velocity, go into the
clouds, accelerate until you come out right above him, then shoot out the
cockpit. You might want to dip out to get feedback, but with a quick
computation, you'll be ok, too.
    First, to do remote ops, we'll do them slower because of the distance,
but slower still based on the masses and momentums involved.
    Second, once the loop becomes too long to be comfortable or too taxing
on the operators' attention span, we can simulate what is happening. Rememeber
we are not manipulating atoms, but large object over fairly well-sensed
terrain. Human purpose can substitute for the limitations of machine design.
    Third, for very large distances or difficult tasks, the operations
will have to take a very long time. And a lot of robustness and redundancy
will have to be built into the machines to endure the long waits with little
attenuation in response or position of the tools.
    Fourth, we can checkout all the equipment and all the procedures and
train operators here on Earth. If a machine and an operator can navigate a
talus field here on Earth with the 30 min delay loop, with a lot simulated
and with very good remote sensing, then they can certainly be successful on
Mars, Venus, the Moon, Etc, etc.
    Fifth, once we know a little more abouthe business of remote operations
and delayed loops, we can export whole packages of movements to robots wherever
and be sure of what will occur because we ran the simulation on Earth, first.
Simulation of what is to happen, giving feedback to the operator, is a key
to getting things done faster.
    Holes in the ground don't just appear magically. Robots don't tip over
because Merlin dreams in his Ice Cave. Arguements of this type are specious at
best, but usually end up sounding like mystic warnings of unforseeable,
unexplainable occurrences, which really have no place in a technological
discussion.

    -Austin

_______________________________________________________________________________
Austin Moseley      [e-mail]
            [phone]
_______________________________________________________________________________

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

End of SPACE Digest V12 #453
*******************