Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V12_4/V12_468.TXT

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Subject: SPACE Digest V12 #468

SPACE Digest                                     Volume 12 : Issue 468

Today's Topics:
                  Re: Hubble
            Re: N-waste sea water dilution
              Re: Venus/Magellan, poles
           Re: Frame sequential TV in space
     Help needed in electric power for space applications
              Re: Launch cost per pound
              Re: Launch cost per pound
        Re: Man-rated SRBs (was Re: Junk the shuttle?)
                  subscribe
              planetary north and names
               Re: Atmospheric nitrogen
                  Re: Hubble

Administrivia:

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

Date: 18 Oct 90 22:11:00 GMT
From: pyramid![e-mail]  (Lon Stowell)
Subject: Re: Hubble

It is unfortunate that NASA is totally unaware of the meaning of
the words "Public Relations".   I have seen prints of Hubble
photos and am fairly impressed.  If they ever fix the sucker
will likely be overwhelmed.

HOWEVER, I am extremely UNDERWHELMED that none of the photos
have made it into mainstream media...specifically network TV.

Is this because the networks refused to show the photo's or
because no one thought to offer them?

I still remember the NASA sponsored research back in the glory
days of space...and the ABSOLUTELY TOTALLY INCOMPETENT p.r.
types at NASA who refuse to make sure that the space race got
full credit for the electronics revolution leading to modern
reliable integrated circuits, medicine, etc.   Who needed
Proxmire with the NASA p.r. types on the job.....


            /|
    \'o.O'
    =(___)=
       U

     THPTH! ACKHH!

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

Date: 13 Oct 90 20:02:38 GMT
From: sdd.hp.com!zaphod.mps.ohio-state.edu!caen!umich!sharkey!fmsrl7!teemc!fmeed1![e-mail]  (Russ Cage)
Subject: Re: N-waste sea water dilution

In article <[e-mail]> [e-mail] (Alan Hepburn) writes:
>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.  By unconcentrating what we concentrate, we
>are merely returning it to its natural form.

Try again.  You are correct that sufficient dilution would reduce the
dose to harmlessness, but

1.)    Such dilution is not possible.
2.)    Our nuclear reactors produce waste which emits energy FASTER
    than the original ore.  It is not creating energy, but it
    IS creating radioactivity in the short term.  (In the long
    term, it depletes total radioactivity.)
3.)    By trying to unconcentrate things in the manner you suggest,
    you make it
    a.)    impossible to isolate any longer, and
    b.)    susceptible to re-concentration through the
        food chain among other methods.
--
Russ Cage    Ford Powertrain Engineering Development Department
Work:  itivax.iti.org!cfctech!fmeed1!cage   (Business only, NO CHATTY MAIL PLS)
Home:  [e-mail]  (Everything else)
I speak for the companies I own, not for the ones I don't.

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

Date: Thu, 18 Oct 90 14:09:00 PDT
From: [e-mail]
X-Vmsmail-To: UTADNX::UTSPAN::AMES::"[e-mail]"
Subject: Re: Venus/Magellan, poles

In SPACE Digest V12 #463, Jeffrey R Kell <[e-mail]>
writes:

>I read all the (various) definitions of "poles" and longitude direction,
>spin, etc., but to ask a possibly silly question,  HOW do you determine
>where a longitude grid BEGINS?  Find Greenwich, Venus? ( ;-) )
>
>One of the (more) unbelievable parts of "Close Encounters" (and others)
>was the use of our latitude/longitude co-ordinate system.  While latitude
>can be inferred (or at least argued over as of late) what basis (if any)
>is there for longitude?

    Longitude and latitude are easy to define for a rotating sphere
with at least one distinct and relatively permanent surface feature.
However, in a brief foray to the library here, I was unable to find
exact definitions of these for any body in the solar system except the
Earth, of course, and the Moon.
    The prime meridian for the Moon is defined as the line on the Moon's
surface that would always appear straight when viewed from the Earth if the
Moon's libration were zero.  In other words, it goes through the middle of
the face pointing toward the Earth.
    For Mars, the the crater Airy is centered at exactly 0 degrees
longitude, 0.5 degrees latitude, so I assume this is the definition of the
prime meridian there.
    The prime meridian of Venus goes through Maxwell Montes, goes just
east of a small but well defined mountain called Eisila near the equator,
and also passes through Alpha Regio.  Judging from the name, I would guess
that some point in Alpha Regio defines zero degrees longitude for Venus.
    The prime meridian of Mercury doesn't seem to pass exactly through
anything, so I couldn't even guess at its definition.
    I don't think it's possible to ascribe longitude to a gas giant.
Even if you have something that lasts a long time like Jupiter's red spot,
the cloud tops at different latitudes go around at different rates.
    All the mapped moons of the solar system have longitude defined, but
just looking at the maps it usually isn't obvious why the prime meridian is
where it is.  Probably the U.S. Geological Survey has a pamphlet explaining
this sort of thing.

_____________
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
"In no future war will the military be able to ignore poisonous gas.
 It is a higher form of killing." -- Fritz 'Father of Gas Warfare' Haber, 1919

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

Date: 17 Oct 90 23:19:59 GMT
From: Teknowledge.COM!unix!snmp.sri.com![e-mail]  (Alan Larson)
Subject: Re: Frame sequential TV in space

In article <[e-mail]> [e-mail] (Gary Coffman) writes:
-In article <[e-mail]> [e-mail] (Eric Pepke) writes:
--I saw some TV pictures from the Shuttle on CNN last night, and when there
--was much motion, the image left behind colored ghost images.  This leads
--me to believe that it is essentially a frame-sequential system.
--
--If so, why is such a system used?  I know that NTSC is notoriously phase
--sensitive, but surely in this digital age we don't need to be limited by
--that.  Are the reasons historical?
-
-It's more likely that they are using old technology single tube cameras
-that suffer from color lag under modest (ie: not full sun) lighting.
-Newer cameras are not as bad about this, but NASA probably hasn't updated
-the cameras due to the paperwork involved in rating anything for space
-use on the shuttle. The newest cameras use chip pickups instead of tubes
-and suffer practically no lag.

  Actually, it is frame (or field, I forget which) sequential color.

  It used to be that they would downlink the video and NASA select would
precede it with warnings that the next transmission is "non-standard".
Later, they would replay it in NTSC.

  About a year ago, they took a small (8mm, I think) camcorder up and
used it for live and recorded NTSC.  It apparently was quite successful.

  During STS-41, they used a second transponder on Satcom 2R, and often
it had the sequential color images on it while the main NASA select
channel had NTSC.  The sequential color looks like a badly flickering
monochrome image -- color bars on it really flicker!

    Alan

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

Date: 15 Oct 90 16:56:31 GMT
From: eagle![e-mail]  (David Liebal)
Subject: Help needed in electric power for space applications

I am about to start doctoral research in the above discipline area, and I
am looking for sources for review purposes.  I have heard that Rensellaer
Polytechnic Institute is a leading academic center in this discipline, and
most cited works I have been able to find to date are from RPI.  Can anybody
verify this, or point me in other directions?

I will gladly summarize to the net if there is interest.  Send e-mail.

Dave

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

Date: 17 Oct 90 09:11:52 GMT
From: ncrlnk!ncr-mpd![e-mail]  (Mike McManus)
Subject: Re: Launch cost per pound

In article <[e-mail]> [e-mail] (Joe Dellinger) writes:
> I just thought I should point out that there's a major (and all too common)
> economic misconception lurking below the surface here. A country can still
> compete successfully in a service even if they are lousy at it! All that
> matters is that they are less lousy at that than they are at other things,
> and that they are willing to have a standard of living to match their overall
> lousy productivity.

I believe this is refered to as "The Law of Comparative Advantage".  It's to
your advantage to do what it is your least bad at, even if others are much
better at it that you (summary of the idea, but not as nice as Joe's
explanation and example!).
--
Disclaimer: All spelling and/or grammar in this document are guaranteed to be
            correct; any exseptions is the is wurk uv intter-net deemuns,.

Mike McManus                        [e-mail], or
NCR Microelectronics                ncr-mpd![e-mail], or
2001 Danfield Ct.                   uunet!ncrlnk!ncr-mpd!garage!mikemc
Ft. Collins,  Colorado
[phone]   Ext. 378

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

Date: 18 Oct 90 15:43:06 GMT
From: sdd.hp.com!samsung!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Launch cost per pound

In article <[e-mail]> [e-mail] writes:
>I thought NASA was ordered by a president to leave those big shuttle
>tanks in orbit for somebody to use.  Did that disappear in the
>Challenger problems ...

No, actually I think it was post-Challenger.  The order was to *make them
available* for commercial use.  Just leaving them in orbit is not a good
idea; it costs payload (the old trajectory in which dropping the tank was
actually more expensive is no longer used), the tanks are big enough and
light enough to be brought down quickly by air drag, and they would be
punctured quickly by debris.  NASA is agreeable in principle to commercial
use of the tanks, but details are still being negotiated.
--
"...the i860 is a wonderful source     | Henry Spencer at U of Toronto Zoology
of thesis topics."    --Preston Briggs |  [e-mail]   utzoo!henry

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

Date: 18 Oct 90 16:20:18 GMT
From: sdd.hp.com!wuarchive!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Man-rated SRBs (was Re: Junk the shuttle?)

In article <[e-mail]> [e-mail] (S Schaper) writes:
>How to the throttleable solids developed by a private US company using LOX for
>the oxidizer measure up in this evaluation?

These are not solids; they are hybrid rockets.  (That is the correct term
for rockets in which one component is liquid and the other is solid.)

The Amroc hybrids are sort of halfway in between liquids and solids in a
lot of ways, including the ones recently discussed.  They still have the
big combustion chamber and the inability to test the flight-ready engine.
On the other hand, they can be throttled or shut down.  And I don't think
they have solids' sensitivity to things like cracks and bond failures,
at least not to the same extent.
--
"...the i860 is a wonderful source     | Henry Spencer at U of Toronto Zoology
of thesis topics."    --Preston Briggs |  [e-mail]   utzoo!henry

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

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Date: 17 Oct 90 14:26:22 GMT
From: sdd.hp.com!wuarchive!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!watserv1!ria!uwovax![e-mail]
Subject: planetary north and names

Regarding two recent postings:

The IAU north direction on planets and satellites is really only intended to
be used for cartographic purposes, not to be imposed on geophysicists and
the like. There is always going to be confusion with this whatever definition
is adopted - planets on their sides like Uranus and Pluto, retrograde
rotation, magnetic fields in opposite senses and so forth. Look at the Halley
literature to see how confusing the situation is - if you use the counter-
clockwise pole as north, it is (assuming we know how it rotates) the one
which points south of the invariable plane.... so the big active region at
the 'north' pole shoots a jet out in a southward direction on the sky.
Clear? Of course not, but if you let the other pole be north and the rotation
be retrograde you contradict most of the existing literature. I use carto-
graphic coordinates with the IAU definition of north, but I would not try
to impose it on anybody else. The only thing that really matters is that you
let people know which north you are using so they can convert if necessary.

Latin names on planets are useful when dealing with an international
community of scientists. How can we use 'vernacular' names like 'Mariner
valleys' in an international setting without being offensive? Look at
medical terminology for all those squishy things inside us, or the latin
names of genera and species of living things - latin is not really a dead
language in science after all. Besides, it is just as easy to learn words
like 'tessera' or 'tholus' as simple terms like 'graben' or 'caldera',
without thinking of them as words in a foreign language.

Incidentally, on a planetary subject, I have just received the new soviet
atlas of Venus (ATLAS POVERKHNOSTY VENERY) from Sojuzkarta. It includes
the entire set of Venera 15 and 16 radar images, contour and geological
maps in a very attractive volume. The text portion is only in russian
but a gazetteer at the end lives latin equivalents. A beautiful book and
a valuable historical record of planetary exploration. Well worth having
in any good library.

Phil Stooke,
Department of Geography,
University of Western Ontario,
London, Ontario, Canada N6A 5C2

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

Date: 17 Oct 90 06:25:01 GMT
From: crash!orbit!pnet51![e-mail]  (S Schaper)
Subject: Re: Atmospheric nitrogen

Chris Jones refers to studies showing increased judgement in an atmosphere
with less nitrogen.

 so, how do we start piping the Argon into the White House and Congress?


UUCP: {amdahl!bungia, uunet!rosevax, chinet, killer}!orbit!pnet51!schaper
The necktie is a device of Mordor
ARPA: crash!orbit!pnet51![e-mail]
INET: [e-mail]

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

Date: 17 Oct 90 21:20:17 GMT
From: haven!uvaarpa!murdoch!astsun7.astro.Virginia.EDU![e-mail]  (Greg Hennessy)
Subject: Re: Hubble

In article <[e-mail]> [e-mail] (Jay Maynard) writes:
#...or were led to think by biased, NASA-bashing news coverage. In fact, the
#last word I heard was that the HST would meet - but not exceed - its design
#specs with the existing optics.

This is incorrect. HST will NOT meet its design specs, if for no other
reason than the spherical abberation means basically a loss of about
three magnitudes in brightness of the observable stars. While many
neat and nifty things can be done with deconvolution and other image
restoration techniques, you can never get back as what you would have
had.

The second generation instruments *MAY* be able to correct for the
spherical abberation. That will depend on how well the wavefront is
known at the time of the design of the instruments. Since some of the
2nd generation instruments are well along in the design phase, there
is not much time to exactly characterise the wave front.

#Of course, the media NASA-bashers didn't want _this_ to get out; it would
#get in the way of their crusade. The fact that the HST's real capabilities
#haven't gotten the coverage that the early troubles did is an eloquent
#comment on just how the media manipulates the public.

While NASA bashers certainly exist, part of the problem (in my
opinion) is that the PI's of the instruments were not experts in the
field of image reconstruction, and were unsure of its capabilities.
When the first images were being shown, the optical astronomers were
cursing the air blue, while the radio astronomers were saying, "Hey
wait, that PSF doesn't look so bad....".

Also it is human nature that bad news gets more headlines than good
news.


--
-Greg Hennessy, University of Virginia
 USPS Mail:     Astronomy Department, Charlottesville, VA 22903-2475 USA
 Internet:      [e-mail]
 UUCP:        ...!uunet!virginia!gsh7w

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

End of SPACE Digest V12 #468
*******************