Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V13_2/V13_204.TXT

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Subject: SPACE Digest V13 #204

SPACE Digest                                     Volume 13 : Issue 204

Today's Topics:
              _This_ is a Flame
             Re: Terraforming, sun shield
        MAJOR SOLAR FLARE ALERT - 25 FEBRUARY
              Magellan Update - 02/25/91
          Re: Government vs. Commercial R&D
         Re: Whither Lunar Observer in FY92?
         Re: Pioneers 7 & 8 Update - 02/11/91
               Re: tuning in on Hubble
                Re: GIF Format
           Re: space news from Jan 7 AW&ST

Administrivia:

    Submissions to the SPACE Digest/sci.space should be mailed to
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----------------------------------------------------------------------

Date: 25 Feb 91 02:25:54 GMT
From: dog.ee.lbl.gov!hellgate.utah.edu!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!rpi!dali.cs.montana.edu!ogicse!pdxgate!qiclab!mntgfx!sequent!crg5![e-mail]  (Nick Szabo)
Subject: _This_ is a Flame

In article <[e-mail]> [e-mail] (Tommy Mac) writes:


>Well, Nick you've done it again, in your letter to Michael Kent.

I don't know about me, but _you've_ certainly done it again.
You attack me personally while expecting that I shall never ever say
anything that would cause one to pause and think?  Since you don't
seem to know the difference between an intelligent argument and a
insult, I will demonstrate a bit of cookery in this post.


>I won't go
>over the details,
>...

You _can't_ go over the details, because you don't know what the hell
you are talking about.


>I'm going to ask you a question, Nick.  Please be so kind as to actually answer
>it.  (I noticed you completely blew off the question about your job.

First, addressing someone's personal life (eg where they work) is
called an "ad hominem" argument.  It is what people resort to when
they have had their prejudices disturbed and are looking for an excuse
to not admit it.

Second, porting Unix software is irrelevant to the discussion.

Third, I assumed you were halfway intelligent and could read the
"Organization" line and/or my e-mail address and see that I work for a
computer company.  I will not underestimate your stupidity again.

Fourth, where I used to work and what I learned there _is_ relevant.
JPL has been first to nearly every planet and moon humankind has
explored, discovering dozens more moons and a wide range of unprecedented
phenomenon in the process.  I am damned proud of my small part in it
(scheduling Voyager, Magellan, Galileo etc. on the DSN).  What have you
done lately except bitch and moan?

Now that you know what a real flame is, what constitutes an insulting
post that might offend someone, perhaps you can shut up and think the
next time I merely state facts that disturb your silly prejudices.
Such thinking will go a long way towards answering this further question
of yours, which I _will_ blow off because you radically mis-stated my
opinion, showing that you haven't thought about my previous answers.



--
Nick Szabo            [e-mail]
Think long-term, act now.

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

Date: 25 Feb 91 22:22:09 GMT
From: csus.edu!wuarchive!zaphod.mps.ohio-state.edu!rpi!uwm.edu!ogicse!zephyr.ens.tek.com!wrgate!mtdoom![e-mail]  (Dan Tilque)
Subject: Re: Terraforming, sun shield

[e-mail] (Ghost in the Machine) writes:
>In article <removed> [e-mail] (Henry Spencer) writes:
>>In article <[e-mail]> [e-mail] (Clayton Cramer) writes:
>>>... Try big dirigibles in the upper atmosphere, carrying algae
>>>to do the CO2 -> O2 conversion.  Much more practical.
>>
>>           The real problem with terraforming Venus, far more significant
>>than the shortage of water or the nearness to the Sun, is the need to get
>>rid of most of the atmosphere somehow.
>
>    An idea:  The two problems with the algae-seeding idea
>are that you have too much oxygen and not enough water?  The logical
>solution is to get a large quantity of hudrogen from a convenient
>source (such as Jupiter) and drop it in.  **WHOOSH** In a large
>fireball most of the oxygen is integrated into water molecules.

Well, you don't want to wait until all the CO2 is converted to O2
before introducing H2.  For one thing, the large amounts of free oxygen
will then recombine with the carbon you've created, undoing all the
good the algae did.  Also, the algae will not be producing pure carbon,
but rather carbohydrates and hydrocarbons.  Unless you add processing to
reduce this to graphite, you're going to need hydrogen as you go along.

What you do is use hydrogen as the bouyant gas in the dirigibles.
Hydrogen will escape and combine with the oxygen produced by the
algae.  This increases the humidity around the dirigible and thus
reduces evaporation of water directly from the dirigible (you don't
want the algae to dry out on you; the environment the dirigible starts
out in is extremely desicating).

>By pulling that gas out of the air, the pressure drops
>precipitously, obviating any need to blow it off with a comet or
>man-made explosive, as is usually assumed.

Actually, what you get is a lot of water vapor which is still in the
atmosphere and is also a greenhouse gas.  You still have to cool the
planet down to let the water condense into oceans.  Then you will have
lower pressure.

---
Dan Tilque    --    [e-mail]

This has nothing to do with optics.  I'm crossposting to sci.space with
followups directed there.

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

X-Delivery-Notice:  SMTP MAIL FROM does not correspond to sender.
Date:    Mon, 25 Feb 91 18:01:49 MST
From: [e-mail] (CARY OLER)
Subject: MAJOR SOLAR FLARE ALERT - 25 FEBRUARY
X-St-Vmsmail-To: st%"[e-mail]"

                        --  MAJOR SOLAR FLARE ALERT  --

                               FEBRUARY 25, 1991

                              Flare Event Summary
                           Potential Impact Forecast
                        SATELLITE PROTON EVENT OCCURRED


                                    --------


MAJOR ENERGETIC EVENT SUMMARY

     A major proton flare exploded off the southwest limb today.  The event
began at 08:06 UT, peaked at 08:19 UT and ended at 09:51 UT on 25 February.
The flare was rated a class X1.2/2N Tenflare and was associated with strong
Type II, III and IV sweeps.  Rich radio emissions were observed from this
flare.  Solar protons arrived and produced a satellite proton event at
12:10 UT on 25 February.  The event was short-lived, however, and
officially ended a little over an hour later at 13:35 UT on 25 February.

     This major X class flare was spawned by Region 6497 which is now
crossing behind the western limb.  The largest regions on the disk (6509
and 6508) are relatively dormant, despite their Beta-Gamma magnetic
configuration.

POTENTIAL TERRESTRIAL IMPACT FORECAST

     This flare was a major event and did produce a coronal mass ejection,
as is evident by the strong Type II and IV sweeps which were observed.
However, this flare was near the western limb and therefore probably will
not produce anything too significant in the way of terrestrial impacts.
There is some uncertainty regarding this, however, as events which occur
near the vernal equinox can become amplified more than expected.

     Preliminary analysis suggests that there is a moderate possibility
that planetary geomagnetic activity could increase to near minor storm
levels on 28 February.  An increase in activity is likely, but the
amount of coupling which takes place is uncertain.

     Geomagnetic activity is expected to increase on 28 February to
planetary A-index values between 20 and 35 for middle latitudes.  A lesser
impact over lower latitudes will likely be observed.  High latitudes will
suffer the worst conditions, with low to moderate intensity minor storming
occurring on 28 February (A-index values between 25 and 38).  Middle
latitude K-indices could range from 3 to 5 on 28 February.  High latitude
K-indices could range from 4 to 7.  Magnetic fluctuations between 400 and 750
gamma could be observed over high latitudes, while middle and low latitudes
will likely witness magnetic fluctuations between 55 and 140 gamma.

     Auroral activity will be most intense over the high latitudes and
extreme northern middle latitudes.  There is a very slight chance that the
impact from this flare could be higher than expected, perhaps with brief
periods of major storming over middle latitudes.  Please note that this is
not very likely, but is slightly possible.  If impacts are greater than
expected, auroral activity could become visible over the northern latitudes
north of about 42-44 North latitude.

     HF propagation should remain above normal until sometime on 28
February when the interplanetary shock is expected to arrive.  An SSC
should be observed with the passage of this shock, sometime on 28 February.
Thereafter, MUF's should drop combined with increased fading and absorption
(particularly over the middle to high latitudes).  High latitude propagation
has become degraded due to a polar cap disturbance which commenced on 24
February and remains in progress.  Things could get significantly worse
over the higher latitudes on 28 February if we are in fact affected by this
flare.  Polar propagation paths will suffer strong absorption and strong
flutter and fading if terrestrial impacts materialize.

     There is a chance for VHF auroral backscatter conditions to
materialize over the middle and high latitudes on 28 February, particularly
during the late afternoon hours and again near midnight.  However, signal
qualities will likely become degraded for most VHF DX signals over the middle
and high latitudes.

     A recovery is expected on 01/02 March to generally unsettled
conditions.  We are nearing the vernal equinox now, so geomagnetic activity
should become a bit more active soon.  A potential geomagnetic storm warning
may be issued within the next 24 hours.

     There is a slight risk for another major flare from Region 6497.  This
risk may exist for the next 24 hours (until 27 February).  No major flares
from the larger regions on the disk are currently anticipated.  Low-level
M-class flaring could occur from Region 6504, 6508 or 6509.


**  End of Alert  **

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

Date: 25 Feb 91 19:45:50 GMT
From: usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Magellan Update - 02/25/91


                          MAGELLAN STATUS REPORT
                           February 25, 1992

     The Magellan spacecraft and its radar system are performing nominally.
All 22 STARCALS (star calibrations) and 6 DESATS (desaturation of the reaction
wheels) during the weekend were successful, with attitude updates averaging
0.056 degree.  As of noon today (PST), Magellan will have completed 1201 orbits
of Venus, with 1027.5 orbits of radar mapping data returned to Earth.

     The gyroscope temperatures are reaching a peak of 69.6 degrees C and are
being watched closely.  The alarm limit is set at 70 degrees C.

     Tomorrow the M1058 command sequence will be sent to the spacecraft.  It
will include the solar panel offpoint and 10 minute early turn from mapping in
order to maintain spacecraft temperatures at acceptable levels.  It will also
contain the commands to playback the specific bit patterns which were recorded
on the DMS-A (Data Management Subsystem) on February 21.  This playback is
Test #3 of the flight recorder "A".
      ___    _____     ___
     /_ /|  /____/ \  /_ /|      Ron Baalke         | [e-mail]
     | | | |  __ \ /| | | |      Jet Propulsion Lab | Is it mind over matter,
  ___| | | | |__) |/  | | |___   M/S 301-355        | or matter over mind?
 /___| | | |  ___/    | |/__ /|  Pasadena, CA 91109 | Never mind.
 |_____|/  |_|/       |_____|/                      | It doesn't matter.

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

Date: 25 Feb 91 22:56:57 GMT
From: zephyr.ens.tek.com!tektronix!sequent!crg5![e-mail]  (Nick Szabo)
Subject: Re: Government vs. Commercial R&D

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

>We badly need somebody doing what Marshall is supposed to do -- propulsion
>engineering -- and the same goes for several of the other centers.

In an earlier post, you wrote that major launch costs reductions would be
be useful for bringing down the cost of space exploration.  I agree.  Observe
that Marshall et. al. have been researching chemical propulsion technology
since the 60's, without bringing about significant drop in costs.  Why
are we to believe that their research can reduce launch costs in the future?



--
Nick Szabo            [e-mail]
Forward in all directions!

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

Date: 24 Feb 91 20:29:20 GMT
From: rml![e-mail]  (jack hagerty)
Subject: Re: Whither Lunar Observer in FY92?

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>the Moon's gravitational field is so lumpy that objects
>left in orbit generally crash on the surface within a few years.

Why is this? I realize that the moon's gravity field causes the nodes of
any orbit around it to precess wildly, but what causes the decay? Or is it
that the nodes precess around enough that the perigee (perilune? periselne?)
eventually intersects a mountaintop somewhere.

- Jack

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

Date: 25 Feb 91 21:31:45 GMT
From: bonnie.concordia.ca!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Pioneers 7 & 8 Update - 02/11/91

In article <[e-mail]> [e-mail] (Ron Baalke) writes:
>>... then Pioneer 12 is on the surface of Venus in
>>pieces (by design!) and Pioneer 13 is still active in Venus orbit.
>
>You've got your numbers reversed for the Pioneer Venus spacecraft...

Wups.  Never could keep those two straight.
--
"But this *is* the simplified version   | Henry Spencer @ U of Toronto Zoology
for the general public."     -S. Harris |  [e-mail]  utzoo!henry

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

Date: 25 Feb 91 21:49:11 GMT
From: dog.ee.lbl.gov!hellgate.utah.edu!cs.utexas.edu!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: tuning in on Hubble

In article <[e-mail]> [e-mail] (H. Peter White) writes:
>Actually, you don't have to work that hard. Someone used one of the satellite
>dishes available at Saint Mary's University in Halifax to 'tune in' on the
>Hubble as it transmitted some image...

Sure he wasn't tuning in on NASA Select which was rebroadcasting it?  One
thing I'm fairly sure of about HST is that it sends nothing that even faintly
resembles a television signal.  The resolution is much higher and it's all
digital data, no analog video at all.  Not impossible to decipher, if you
know the formats and have a sufficiently fast computer waiting for it as
it comes over, but not something I'd expect to see done with off-the-shelf
dish equipment.
--
"But this *is* the simplified version   | Henry Spencer @ U of Toronto Zoology
for the general public."     -S. Harris |  [e-mail]  utzoo!henry

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

Date: 25 Feb 91 10:39:54 GMT
From: att!pacbell.com!tandem!netcom![e-mail]  (Avery Colter)
Subject: Re: GIF Format

Basically, GIF is a generic pixel-by-pixel color format, generic enough
that a decoder can be written in theory for any machine with graphics
capability.

On an IBM style home computer, there are several GIF translators out in
the public domain for each of the many and varied graphic modes that can
be implemented out of an Intel computer.

--
Avery Ray Colter    {apple|claris}!netcom!avery  {decwrl|mips|sgi}!btr!elfcat
[phone]   "I feel love has got to come on and I want it:
                  Something big and lovely!"         - The B-52s, "Channel Z"

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

Date: 25 Feb 91 15:28:37 GMT
From: dimacs.rutgers.edu!aramis.rutgers.edu!athos.rutgers.edu![e-mail]  (Steve Masticola)
Subject: Re: space news from Jan 7 AW&ST

Henry Spencer writes:

> Postmortem on the Dedicated Display Units that failed aboard Astro-1
> shows identical failures, tentatively the result of debris clogging
> heat sinks.  The debris is still being analyzed but "...it looked
> like it consisted of blue lint, human hair of several different colors,
> several colors of paint chips, a piece of food that looked like a
> piece of a peanut, and some clear bits, probably of glass and plastic".

Slobs.

Oh, well. Given that this is probably going to happen again, is there
a reasonable way to instrument the heat sinks so that they can detect
clogging, and design them so that they can be cleaned in space? Even a
small temperature or airflow sensor would be adequate instrumentation,
if the heat sinks were designed for maintenance in flight.

I thought that the ability to maintain equipment was supposed to be
one of the purposes of having a human presence in space.

- Steve ([e-mail])

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

End of SPACE Digest V13 #204
*******************