Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V13_0/V13_081.TXT

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Subject: SPACE Digest V13 #081

SPACE Digest                                      Volume 13 : Issue 81

Today's Topics:
           Re: space news from Dec 17 AW&ST
               Magellan article
              trace contaminants
              Re: 2 dimensional objects
          Re: What is cosmological constant?
           Re: Salyut 7 picks up extra term
        New ESA technical standards documants
          Re: What is cosmological constant?
           Availability of the Ames SPACE archives

Administrivia:

    Submissions to the SPACE Digest/sci.space should be mailed to
  [e-mail].  Other mail, esp. [un]subscription requests,
  should be sent to [e-mail], or, if urgent, to
             [e-mail]

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

Date: 24 Jan 91 17:11:34 GMT
From: usc!elroy.jpl.nasa.gov!freedom![e-mail]  (David Cornutt)
Subject: Re: space news from Dec 17 AW&ST

[e-mail] ("Allen W. Sherzer") writes:


>Had NASA been up front with the risks and run a better operation the
>Chalanger disaster PR fallout wouldn't have been that bad. After all,
>Apollo 1 didn't come close to killing Apollo.

Yes, it did.  At the time, there were a number of calls in Congress to
kill the program; the speeches sounded almost exactly like what we
hear today ("we need to spend money here on Earth instead of throwing
it away in space", etc.).  The program was more or less shut down
for about two years.  Only a renewed Cold-War threat of the evil
Russkies (:-) getting ahead of us saved it.

There are folks down at the Cape who still cringe at the memory of the
months following Apollo 1 -- not only because of the horror of the
accident, but because every one of them was made to feel personally
responsible for it.  They were used as national whipping boys, just
like after Challenger.

--
David Cornutt, New Technology Inc., Huntsville, AL  [phone]
([e-mail]; some insane route applies)
"The opinions expressed herein are not necessarily those of my employer,
not necessarily mine, and probably not necessary."

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

Date: 24 Jan 91 20:01:24 GMT
From: swrinde!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Magellan article

Associated Press -- 1/24/91
"Magellan Venus"
By Lee Siegel

"Volcanic bulges that resemble giant spiders provide more
evidence that Venus' landscape is shaped by huge blobs of
molten rock rising from inside the planet, say Magellan
spacecraft scientists."

The AP Los Angeles-based science writer says the bulges,
some more than 100 miles wide, support the theory that Venus'
terrain is being sculpted by "hot spot tectonics" or "blob
tectonics."

The story says a similar process created the Hawaiian chain of
islands but the dominant geologic process on Earth is plate
tectonics.

The writer says the Venus scientists are calling the features
"arachnoids" because of their resemblance to spiders - a class
of animal called arachnids.

The story cites one Venus scientist, Ellen Stofan, who suggests
that the arachnoids may just be the early stages of what might
turn out to be much larger bulges later.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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

Date: 25 Jan 91 00:06:12 GMT
From: EARTH.ARC.NASA.GOV![e-mail]  (FINN)
Subject: trace contaminants


   Are you doing or planning research *related* to removal, generation,
or detection of TRACE COMPONENTS or CONTAMINANTS in air or water?
[Examples: removal by adsorption, removal by reactive plasma, generation
by algae, generation by offgassing, etc.]  If so, I would like to hear
from you.  I am beginning studies of trace contaminant control in near-
closed-loop air and water systems for long-duration manned space
missions, and would like to learn what others are doing in related
areas.  Responses to this letter will assist me in forming a references
database, and may provide a starting point for some dialogue/discussion
concerning various aspects of trace contaminant control: issues,
theories, experiments, innovations, technologies, etc.

   Electronic or postal mail responses are fine.  Brief summaries and
short bibliographies are welcome, as are any comments or suggestions.
Please pass this letter on to anyone who might be interested but may not
otherwise see it.  Thank you for your interest.

                        Dr. John E. Finn
                        Advanced Life Support (Regenerative Systems)
                        NASA Ames Research Center
                        M/S 239-11
                        Moffett Field, CA  94035
                        [e-mail]

P.S.: if you are sending e-mail and the message is not accepted here,
please either try again later or send a letter.

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

Date: 25 Jan 91 07:20:58 GMT
From: munnari.oz.au!brolga!covax.commerce.uq.oz.au![e-mail]
Subject: Re: 2 dimensional objects

In article <[e-mail]>, [e-mail] (Erik Kilk) writes:
>
> I remember Carl Sagan's TV series on the PBC devoted a segment on such
> flat people.  I can't remember the series name, but it might have been
> "Universe." He animated flat people as disks and their homes had just
> walls (drawn as lines like in a set of house plans).

I think you are referring to the 13 Part series "Cosmos".  There was also a
book of the same name summarising the series.  Very good, but then I'm also
a member of the Planetary Society :-)

To give the correct credit, I think much of his analogy was drawn from
another author (who I can remenber).  'Flatland' seems to come to mind
could have been "Flatland : a romance of many dimensions" by Edwin Abbott.
My copy of Cosmos is at home.

[...deleted]

>
> I believe all this was to suggest that our 3rd dimension is to the flat
> people as a 4th dimension might be to us!

Yes, the discussion (from memory) was about 4D space-time.  He also showed
what the shadow (?) of a 4D 'cube' was like.

--
David E. Bellamy        Email: [e-mail]
Dept. Commerce, University of Queensland, St. Lucia, AUSTRALIA

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

Date: 20 Jan 91 09:39:45 GMT
From: jarthur!nntp-server.caltech.edu![e-mail]  (Todd A. Brun)
Subject: Re: What is cosmological constant?

In article <[e-mail]> [e-mail] (joefish) writes:
>    It is difficult for me to understand why Einstein's Cosmological
>constant is discussed other than in the interest of the history of
>the General Theory of Relativity.
>      When Einstein introduced it, it was assumed that our galaxy
>represented the entire universe, and to be stable, a finite universe
>needed the constant.
>      The type of universe could only have been steady state at the
>time, so Einstein did not regret the choice, he merely acknowledged
>that if he had known that there were countless galaxies and they
>were apparently receding, he would never suggested (or considered)
>his cosmological constant.
>     There is no reason to consider applying his constant at
>the present time, but it is useful to remember that the Big Bang
>was never thought of until Hubble's discoveries in the 20's and
>30's.
>
Reportedly, Einstein called the cosmological constant "the biggest blunder of
my life".  However, it is a mistake to dismiss it as only an historical
footnote.  I'm not an astrophysicist, but they hang out right down the hall
from me; and most of them believe that a non-zero cosmological constant
is quite plausible, and least at one time.  One of them even went so far as
to say that "most" cosmologists believe that at one time the cosmological
constant was non-zero.

Einstein originally invoked the cosmological constant to insure a steady-state
universe.  This is almost certainly incorrect.  But nowadays cosmologists
invoke it for the opposite reason -- to explain a tremendously accelerated
rate of expansion in the early universe.  One of the most successful groups
of cosmological theories (but more on that in a second) are the so-called
inflationary models.  To simplify (since I don't know the details myself),
they posit that at one time the universe was in a rapidly-expanding
'inflationary' state, which caused it to expand enormously in a very short
time.  As there isn't any known reason why this should happen, it is common
to invoke a non-zero cosmological constant in the early universe.

Why bother to do this?  Because, until recently anyway, the inflationary
models were the most successful at explaining what we actually see.  Nowadays,
almost all cosmological models are in very bad shape, being attacked from
both ends.  On the one had, recent discoveries of very large scale structure
in the universe (the 'Great Wall' and 'Great Voids') has made it clear that
the present universe is much more inhomogenous that was originally though;
on the other hand, measurements of the cosmic background radiation by COBE
have made it clear the early universe was very much more homogenous than
originally thought.  Under this twin strain, about 90% (it may be more by now)
of all cosmological models have quietly expired.  If COBE manages to push its
accuracy to about 1 part in 10^7, it will pretty much have scotched the lot.

Anyway, if the cosmological constant was at one time non-zero, the real puzzle
is why the heck it's so small now.  Having a non-zero cosmological constant
is essentially the same as saying that completely empty spacetime isn't
flat, which would imply that special relativity isn't actually right.  Since,
as has been often pointed out in this august newsgroup, SR is the most
well-tested physical theory of all time, the corrections due to the constant
must be truly minute.  Considering the shakiness of all these models in the
light of current experiments, your guess is probably as good as anyone
else's.

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

Date: Mon, 21 Jan 91 08:36:52 PST
From: [e-mail]
X-Vmsmail-To: UTADNX::UTSPAN::AMES::"[e-mail]"
Subject: Re: Salyut 7 picks up extra term


In SPACE Digest V13 #067,
isis!scicom![e-mail]  (Bruce Watson) writes:

>Salyut 7 has picked up the extra term in the polynomial that
>modifies the mean motion.  The period as of day 91 09.31 is
>89.93 minutes with a mean height of 271 kms.
                                         ^^^
The plural of km is km.
_____________
Dale M. Greer, whose opinions are not to be confused with those of the
Center for Space Sciences, U.T. at Dallas, UTSPAN::UTADNX::UTDSSA::GREER
                        "I will continue to use my boat." -- George Bush

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

Date: Tue, 22 Jan 91 15:47:31 CET
From: Hermann Schneider <[e-mail]>
Subject: New ESA technical standards documants

For interested people:

   ========================================================================
        PUBLICATION OF NEW SPACE DATA COMMUNICATIONS STANDARDS

   The  two  following  Space  Data Communications Standards are now
   available in their final PSS format:

   W   "Telemetry  Channel  Coding  Standard",ESA   PSS-04-103,Issue
       1,Sept.1989

   W   "Ranging Standard",ESA PSS-04-104,Issue 1 of Volume 1:"Direct
       Ground to Spacecraft Ranging",April 1990

   Copies can be obtained from the ESA Publications Division (IP) by
   contacting Mr.F. De Zwaan via PROFS.

   IP  is also at your disposal to provide copies of the two already
   published Space Data Communications standards:
                       --------------------------------------

   W   "Radio Frequency and Modulation Standard",ESA PSS-04-105

   W   "Packet Telemetry Standard",ESA PSS-04-106

   Finally, one other PSS document in the same series is expected to
   be published by IP during February 1990 :

   W   "Packet  Telecommand  Standard",ESA  PSS-04-107,Issue  1,June
       1990

   Until then, copies of this document in a provisional  format  can
   be obtained from:

   Mr.Lelann (ESTEC,WGO*,Ext.3720), or Mr.D.Rouat (ESTEC,WDP,Ext.3678)
   in the absence of Mr.Lelann.

Regards Hermann Schneider
        (Communication Systems Programer)
        ESOC (European Space Agency's Operations Centre)

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

Date: 23 Jan 91 15:30:01 GMT
From: mcsun!unido!mpirbn![e-mail]  (Daniel Fischer)
Subject: Re: What is cosmological constant?

In article <[e-mail]> [e-mail] (joefish) writes:
>    It is difficult for me to understand why Einstein's Cosmological
>constant is discussed other than in the interest of the history of
>the General Theory of Relativity. [...]
>     There is no reason to consider applying his constant at
>the present time...
>
>Joe Fischer      [e-mail]
     ^^^^^^^
Dan Fischer just can't resist posting what I heard in a lecture here just one
hour ago: the Cosmological Constant does exist, it is a fundamental constant
of nature like Planck's or gravity's, and its most likely value is:
1/(36*10^18) 1/(lightyears)^2.  The age of the uiverse is (30+/-5)*10^9 years.
                                                            Any questions?  :-)

Well, let me give just a bit more background (sorry, have still to read 638
articles in alt.desert-storm and a mailbox full of flames... :-<):
What Prof. W. Priester just presented is a cosmological model that seems to be
capable of explaining virtually all cosmological problems of 1991:
 o The existence of the cosmic large-scale structure that just killed the
     famous Standard CDM Model (see NATURE Jan. 3 and SCIENCE Jan. 18, 1991),
 o Why even the most distant quasars (with z>4.5) still show so many emission
      lines of heavy elements that hint at a high age>>10^9 years,
 o And why a Hubble Constant around 90 km/s/Mpc is consistent with an age of
      the universe >=18*10^9 years.

All one has to do is setting the Cosmological Constant, a genuine constant of
integration in Einstein's field equations (giving the inherent curvature of
space-time) not canonically = zero as it is usual, but treating it as a free
parameter that has to be determined from observations. And what you get is
a universe that for the first 20*10^9 years expands very slowly, providing
ample time for the formation of large-scale structure ('bubbles & voids')
as well as quasar formation (when the age is already around 10^10 years).
Later the expansion speeds up and has now reached almost the final value.

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

Date: 24 Jan 91 06:48:34 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: Availability of the Ames SPACE archives

I'm pleased to announce that the SPACE archives, located on ames.arc.nasa.gov
are once again available via e-mail service.  To access the archives, send
a letter to [e-mail] (or ames!archive-server).  In
the subject of your letter (or in the body), use commands like:

send SPACE Index
send SPACE SHUTTLE/ss01.23.91.

The capitalization of the subdirectory names is important.  All are in caps.
The following is a list of the subdirectories that are currently available:

APOLLO          GIOTTO          MANIFEST        PRESS.KIT       ULYSSES
ASTRO           HEADLINE.NEWS   MARS.ROVER      PRESS.RELEASE   VICAR
BBXRT           HST             MCSR            PROGRAMS        VOYAGER
COBE            HUT             MISC            RADIO           WEATHER
CONTRACT        IMDISP          NTE             SHUTTLE         WUPPE
CRAF            OSR             SPACE.CLASSROOM FRR             PAYLOAD.STATUS
SPACELINK       GALILEO         LAUNCH.ADVISORY PEGASUS
GIF             MAGELLAN        PIONEER         UIT

The GIF directory contains files in GIF format.  A few have been uuencoded so
that they be mailed, but unfortunately the majority will not survive mailing.
This will be rectified in the future.  The VICAR directory has two Magellan
images in VICAR format.  A PC program capable of displaying these files is
found in the IMDISP directory, although it is still a binary file (ZIP format)
and so it is not suitable for mailing at this time.

Any problems with the archive server should be reported to me as soon as
possible.

And as always, the archives are also available via anonymous ftp to
ames (128.102.18.3).  Directory is /pub/SPACE.

                            -Peter Yee
                            [e-mail]
                            ames!yee

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

End of SPACE Digest V13 #081
*******************