Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT_ZIP/spacedig/V09_4/V9_480.ZIP/V9_480

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Date: Sat, 10 Jun 89 03:16:40 -0400 (EDT)
Subject: SPACE Digest V9 #480

SPACE Digest                                      Volume 9 : Issue 480

Today's Topics:
        Looking for new Space Digest moderator
               Re: SPACE Digest V9 #474
           Re: space news from May 1 AW&ST
                TDRSS question
          Re: comet strike in the carolinas?
         Re: Venus & the Greenhouse effect..
         Re: Venus & the Greenhouse effect..
             Re: Gemini and Rogallo wing
              Neptune animation
         Re: Venus & the Greenhouse effect..
        Fluid Dynamics and Computer Animation
          Re: comet strike in the carolinas?
----------------------------------------------------------------------

Date: Fri,  9 Jun 89 11:28:02 -0400 (EDT)
From: Ted Anderson <[e-mail]>
X-Andrew-Message-Size: 2838+0
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Subject: Looking for new Space Digest moderator
CC: Space-Request <[e-mail]>

I am leaving my job at CMU and will need to hand off the operation of the Space
Digest to someone else.  I've been running the digest for between 9 and 10 years
and through two jobs.  My new job will be much busier and I will no longer be
able to afford the time and attention to run the digest.  This is a call for a
volunteer to be the new moderator.

There are a few practical considerations.  The digest is mostly operated in the
Internet environment, which uses mail for distribution.  The netnews group
sci.space has totally different mechanisms and takes care of itself.  This means
that the moderator will need excellent access to the Internet and good
connections to Usenet, Bitnet, CSNet and other networks' gateways.

The digesting software provides semi-automatic operation and is mostly written
in gnu-emacs.  This is a widely available (free) editor which runs on most Unix
systems.  The current system also contains components to interface with CMU's
Andrew Mail System.  Since I previously ran the digest from a Sun NFS Unix
system, using Berkeley mail software, it shouldn't be too bad to adapt it to
most robust mail systems.  Ironically, the Unix systems on which this software
runs are also those systems which are least likely to use it because of the
availability of sci.space via Usenet.

As far as the time commitment goes I would estimate that you could operate the
digest in about 4 hours per week.  Perhaps someone could get by for less, and it
would be easy to spend more.  Clearly some extra time would be required
initially to get everything set up.  It is possible that the job could be split
among a group of people.  It would depend on what capabilities each brings to
the job but it seems that, archiving (which can take a fair amount of disk
space), mail distribution (which can impose quite a heavy load on the mailer),
and the digestification could be separated.  There are other possibilities.

The Space Magazine, which contains a subset of the submissions to the digest, is
reasonably well integrated into the digesting software and really adds very
little work to the process.  I would hope that this addition could be maintained
and grow with the change in moderators.

Because of my reluctance to make this change, and because the I have been very
busy with the job transition, I have put off sending this note to the last
minute.  Today is my last working day at CMU.  Monday I start at the new company
and will have no network access for at least a week.  After that, I hope to move
quickly to bring a new moderator up to speed.  If there are outages in the next
few weeks you will know why, please bear with me.

If you have some time to devote to maintaining and improving communication
between space enthusiasts here is your opportunity.  I look forward to hearing
from you.

        Ted Anderson

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

Date: 7 Jun 89 17:15:38 GMT
From: ncrlnk!ncrcce![e-mail]  (Wayne D. T. Johnson)
Subject: Re: SPACE Digest V9 #474

In article <[e-mail]> [e-mail] writes:
>
>Yet another example of how markets react faster and with less
>sensitivity to entrenched interests than governments....

That could be good, or bad.  What if market research were responsable for
launching ICBMs?  I know several people who would like to nuke China right
about now, well, at least certain people over there.
--
Wayne Johnson                 (Voice) 612-638-7665
NCR Comten, Inc.             (E-MAIL) [e-mail] or
Roseville MN 55113                    [e-mail]
These opinions (or spelling) do not necessarily reflect those of NCR Comten.

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

Date: 7 Jun 89 01:37:13 GMT
From: aeras![e-mail]  (Tom Neale)
Subject: Re: space news from May 1 AW&ST

In article <[e-mail]> [e-mail]
 (Henry Spencer) writes (and correctly I might add):

>If I haven't got the terms mixed up, no, they are not the same thing.
>Rogallo's concept was a flexible wing, with shape held by rigid members
>or shroud lines or both.  Typically it had a single surface and was
>triangular.  A parafoil is a gliding parachute, with two surfaces kept
>apart by ram pressure and a rectangular shape.  Parafoils have largely
>replaced circular parachutes for high-performance sport parachuting.
>They are parachutes first and wings second.
[actually without the lift effect from the wing they are lousy parachutes]

You've got the terms just right, Henry.  I think the technical term
is "ram air inflated, semi rigid airfoil. It was invented and patented
by Domina Jalbert in the 1960s.  Pioneer has been working on
this recovery system for many years.  It is a very, very large ram
air parachute (several thousand sqaure feet I think; sport parachutes
for 1 person are 150-300 sqaure feet).

The really tricky part is the deployment (reefing) system that allows the
thing to open slowly so as not to damage the payload or the parachute.
An abrupt opening at high speed will cause the fabric to fail and the
parachute to self destruct, or at least subject the payload to such a
high deceleration force (>>15 G) as to damage it.

Because of the extreme altitudes they can afford to open it very slowly,
like one or two cells (ram air compartments) at a time.  I don't know
how this is accomplished but I'll try to find out from some parachute
designing friends of mine.
--
Blue skies,    | ...sun!aeras!tneale    |
        | in flight:     N2103Q    |         The hurrieder I go
Tom Neale    | in freefall:   D8049    |         the behinder I get.
        | via the ether: WA1YUB    |

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

Date: Wed, 7 Jun 1989 10:50-EDT
From: [e-mail]
Subject: TDRSS question

Does anyone know why NASA chose not to have a 3rd TDRS satellite over
India to complete the coverage? I thought the TDRS satellites could
also relay from one to the other, so a ground station there would not
be a necessity. I'm quite sure their ground link data rates are higher
speed.

I've piles of TDRSS info but I've not seen a single mention of why they
choose to leave the 15% LEO gap.

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

Date: 7 Jun 89 18:35:53 GMT
From: att!ihlpl![e-mail]  (Knudsen)
Subject: Re: comet strike in the carolinas?

I've read a little about those features, and the author ascribed
them to meteor strikes.  TOo long ago to remember where I read this.

A somewhat wilder theory has been printed to the effect that both
the Chicago fire of the 1870's and a series of even more destructive
forest fires in Wisconsin on the same day were started by a comet,
whose chunks included plenty of frozen methane gas.

Chicago firemen reported blue flames seemingly from nowhere in
the basement of houses (that presumably didn't have gaslight
hookups).  And the Wisconsin fires broke out over a wide area
nearly simultaneously.  Hard to believe that many careless milkmaids
let their cows kick over lanterns all at once ;-).
--
Mike Knudsen  Bell Labs(AT&T)   att!ihlpl!knudsen  [e-mail]
  Round and round the while() loop goes;
  "Whether it stops," Turing says, "no one knows!"

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

Date: 7 Jun 89 03:20:41 GMT
From: zephyr!tektronix!percival!parsely!bucket![e-mail]  (Leonard Erickson)
Subject: Re: Venus & the Greenhouse effect..

In article <[e-mail]> [e-mail] (Kelly St.Clair) writes:
<> [Is there any reason that Venus could not be cooled and terraformed?]
<
<Is there any reason (besides needing space so that we can keep breeding like
<flies)s) that we should?

First of all, please note that the countries with the birth rates that
are greater than ZPG rates, are those that aren't fully industrialized yet.
(one of the "benefits" of giving them modern medicine, without a modern
industrial base or a western-style culture). Further discussion of *this*
point belongs in sci.environment.

Second, we may need to pratice terraforming on Venus so we can do it right
when we start terraforming *Earth*. I strongly suspect we may need to
restore an earth-like environment to this planet. :-(
<
<Most important of all:
<Is there anything that gives us the *RIGHT* to remake another world in our
<own image?
<
Well, we have at least as much "right" as did the blue-green algae that
through pollution, killed of 99% of all the species on Earth at the time.
Oxygen was a "pollutant" then.

And the coral reefs are another example of a lifeform making *major*
alterations in the planet.
--
Leonard Erickson        ...!tektronix!reed!percival!bucket!leonard
CIS: [70465,203]
"I'm all in favor of keeping dangerous weapons out of the hands of fools.
Let's start with typewriters." -- Solomon Short

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

Date: 8 Jun 89 05:47:23 GMT
From: jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Venus & the Greenhouse effect..

In article <[e-mail]> [e-mail] (Steve Hix) writes:
>Say, if we throw enough comets and other iceballs at Venus to get the
>water back, and if they're placed correctly, maybe we could get the
>planet's spin rate up some.
>
>Probably not enough comets, huh?

Probably not.  Dismantling one of the ice moons of the outer planets would
give us an adequate amount of water for Venus, but spinning it up is lots
harder.  I saw, in JBIS I think, a proposal to use the half-dozen biggest
asteroids to kill two birds with one stone:  blast most of the atmosphere
off into space and spin the planet up as well.  You can guess how. :-)
Unfortunately, even the big asteroids are not really as big as one would
like for the job -- the "day" would still be a week or so long.

Sure would be spectacular, though.
--
You *can* understand sendmail, |     Henry Spencer at U of Toronto Zoology
but it's not worth it. -Collyer| uunet!attcan!utzoo!henry [e-mail]

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

Date: 7 Jun 89 21:41:40 GMT
From: mcvax!ukc!reading!cf-cm!cybaswan![e-mail]  (Steve Hosgood)
Subject: Re: Gemini and Rogallo wing

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In any case, note that the Rogallo Gemini would not have had a long gliding
>range, so it wouldn't have gotten a military crew out of hostile territory
>in the event of a major guidance foulup.  The main importance of precision
>landing was getting rid of the recovery fleet.
>--

Anyone with access to a National Geograpic collection may want to check out
the photo on page 370, March 1964. This shows an artist's impression of the
proposed Rogallo wing in action with Gemini. My apologies for linking this
project with Apollo in my earlier posting - I was working from memory, and
slipped up.

The wing design shown gets its rigidity from inflatable leading edges,
keel and cross-tubes! Hang Glider pilots who've ever flown a 'Bog Rog'
will also notice it has no keel pocket, which must have made it rather
difficult to steer.

As Henry says, it was expected to glide about 20 miles - not enough to escape
'enemy territory'.

Steve

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

Date: Thu,  8 Jun 89 16:19:46 PST
From: Peter Scott <[e-mail]>
Subject: Neptune animation
X-Vms-Mail-To: EXOS%"[e-mail]"

The NAIF (Navigation Ancillary Information Facility) people here have a
little animation running on a Ramtek of the rotation of Neptune (just under
half a rotation).  You can clearly see the big spot at about 20 deg south,
and there appears to be a smaller white spot attached to it on the south
side.  The only banding visible is a broad slightly darker band from
around 70 to 80 deg south.  Too early to tell whether mottling on the
rest of the planet is noise in the system.

Peter Scott ([e-mail])

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

Date: 8 Jun 89 14:27:39 GMT
From: rochester![e-mail]  (Paul Dietz)
Subject: Re: Venus & the Greenhouse effect..

In article <[e-mail]> [e-mail] (Henry Spencer) writes:

>Probably not.  Dismantling one of the ice moons of the outer planets would
>give us an adequate amount of water for Venus, but spinning it up is lots
>harder.  I saw, in JBIS I think, a proposal to use the half-dozen biggest
>asteroids to kill two birds with one stone:  blast most of the atmosphere
>off into space and spin the planet up as well.  You can guess how. :-)
>Unfortunately, even the big asteroids are not really as big as one would
>like for the job -- the "day" would still be a week or so long.

The worst problem with terraforming Venus is getting rid of the
oxygen.  Cloud-living algae would not work, since they would release
free oxygen.  Sixty-five bars of O2 would be as lethal as ninety bars
of CO2.  So, you shouldn't important water from the outer solar
system, but, rather, molecular hydrogen.

Perhaps a better method is to import deuterium, build a bunch of
*really* big bombs, and blast most of the CO2 into space.  This would
probably be fastest, and would let the surface cool quickly.  You'd
need several cubic miles of liquid deuterium, although I suspect very
large bombs could burn more exotic, less neutronic, fuels, since the
square-cube law helps.

Solving the length-of-day problem with orbiting mirrors/shades would be,
in comparison, an easy task.  You'd probably want shades anyway to keep
the temperature comfortable.

Then again, a Venus with a thick atmosphere has certain advantages as
a site for industrial operations (industrial scale transmutation, for
example, using the atmosphere as a radiator).

    Paul F. Dietz
    [e-mail]

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

Date: 8 Jun 89 20:55:35 GMT
From: m2c!umvlsi![e-mail]  (Jim Mazzu)
Subject: Fluid Dynamics and Computer Animation



Hello!

I would like to establish communication links with those of you
conducting R&D in FLUID DYNAMICS, TURBULENCE, SCIENTIFIC VISUALIZATION,
or COMPUTER ANIMATION.

As a graduate student in Mechanical Engineering, I am producing
an educational video on Potential Flows.  The equations of motion
are used to create object and motion files, which are then viewed
and animated using AMIGA P/C's.  At this point, the sequences are
dumped directly to video.

I am also conducting an analysis of wind data associated with a
330-KW horizontal axis wind turbine.

If you are interested in discussing any of these topics, please
reply through e-mail.  I'm looking forward to hearing from you!

Jim Mazzu

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

Date: 8 Jun 89 18:15:33 GMT
From: frooz![e-mail]  (Doug Mink, OIR)
Subject: Re: comet strike in the carolinas?

From article <[e-mail]>, by [e-mail] (Knudsen):
> I've read a little about those features, and the author ascribed
> them to meteor strikes.  TOo long ago to remember where I read this.
>
> A somewhat wilder theory has been printed to the effect that both
> the Chicago fire of the 1870's and a series of even more destructive
> forest fires in Wisconsin on the same day were started by a comet,
> whose chunks included plenty of frozen methane gas.

There is a book about this theory, "Mrs. O'Leary's Comet!", by Mel
Waskin, subtitled "Cosmic Causes of the Great Chicago Fire".  It was
published by Academy Chicago Publishers in 1985, just in time for
the Comet P/Halley hysteria.  The theory is that Comet Biela, which
was observed to split into two and then never seen again, died and
hit the earth.  The theory was first proposed by Ignatius Donnelly in
a book called "Ragnarok:  The Age of Fire and Gravel", first published
in 1883.  It seems to me to be somewhere between Velikovsky and reality
on the spectrum of believability.  Donnelly's theories, as described in
Waskin's introduction, are definitely Velikovskian (or, more accurately,
Velikovsky's ideas are Donnellian), and imply a gross misperception of
the nature of cometary matter.  Waskin's reinterpretation is less
scientifically implausible, but still requires some leaps (or maybe
jumps) of faith.

Doug Mink, skeptical astronomer

Internet:  [e-mail]
BITNET:    mink@cfa
SPAN:      cfa::mink
Phone:     [phone]
FTS:       830-7408
USMail:    CfA, 60 Garden St., Cambridge, MA 02138

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

End of SPACE Digest V9 #480
*******************