Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V10_2/V10_203.TXT

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Subject: SPACE Digest V10 #203

SPACE Digest                                     Volume 10 : Issue 203

Today's Topics:
             Re: Jupiter Balloon
  Re: NASA Administrator Truly's remarks to the National Press Club
            Re: Magnetic shielding
              Re: Fragile Space Shuttle
            Re: Moon Colonies / Ant Tanks?
         Re: Manned Jupiter Mission (was Re:
      Re: a glimpse behind Venus's veil (really Science)
 Re: Manned Jupiter Mission (was Re: Condensed CANOPUS - August 1989)
             Re: PowerSat Options
         Re: Voyager/Galileo Camera function
            Re: Moon Colonies / Ant Tanks?
         Re: Voyager/Galileo Camera function
              Re: Wood in space
            Re: Moon Colonies / Ant Tanks?
----------------------------------------------------------------------

Date: 2 Nov 89 17:32:43 GMT
From: cs.utexas.edu!mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Jupiter Balloon

In article <[e-mail]> [e-mail] (George William Herbert) writes:
>    A friend and I (George and Frank Crary) just worked out
>specs for a nuclear heated balloon for dropping into the Jovian
>atmosphere and leaving for an indefinite amount of time (years?).

For heaven's sake don't tell the Christic Institute! :-) :-) :-)
--
A bit of tolerance is worth a  |     Henry Spencer at U of Toronto Zoology
megabyte of flaming.           | uunet!attcan!utzoo!henry [e-mail]

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

Date: Thu, 2 Nov 89 07:38:20 PST
From: mordor!lll-tis!oodis01!riacs!rutgers!pnet01.cts.com![e-mail] (Jim Bowery)
To: ucsd!nosc!crash![e-mail]
Subject: Re: NASA Administrator Truly's remarks to the National Press Club

Richard H. Truly speaking before a gullible National Press Club asks:
>        I wonder what Orville might think today if he
>visited a NASA aeronautics center where they are working on a
>National Aero-Space Plane that someday will take off from a
>runway, fly to orbit and land like a conventional plane?

I'm sure he'd be reminded of the Langley Flyer.

>     The space shuttle continues to be key to our access to
>space.  It is our workhorse, our conestoga wagon.

Oh, I didn't know that the conestoga wagon required the lives work
of thousands of people to develop it, with each copy requiring about
2 thousand man-lives to build and each trip about 2 hundred man-lives.

No wonder Truly is NASA administrator.  He's a wealth of information.

>     Meanwhile, we are depending heavily on America's commercial
>sector to provide launch services to us, using expendable rockets
>for cargos that do not require human intervention.

Yeah, a fraction of a percent of NASA's budget.  NASA would just
go belly up tomorrow if it weren't for all those commercial launch
services they have purchased since presidential policy directed
them to do so several years ago -- what is it up to now.... 2?


I want to take a poll on this speech.  On a scale of 1 to 10, how
nauseated did it make you?  (with 1 being only moderately queasy, to
10 being like the guy in the restaurant scene in Monty Python's
"The Meaning of Life")
---------------------------------------------------------------------------
Jim Bowery      PHONE: [phone]     BE A SPACE ACTIVIST
PO Box 1981            GET OFF THE NET AND SET UP AN APPOINTMENT WITH YOUR
La Jolla, CA 92038                         CONGRESSMAN!
---------------------------------------------------------------------------
UUCP: {cbosgd, hplabs!hp-sdd, sdcsvax, nosc}!crash!pnet01!jim
ARPA: crash!pnet01![e-mail]
INET: [e-mail]

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

Date: 2 Nov 89 08:25:04 GMT
From: bungia!orbit!pnet51![e-mail]  (S Schaper)
Subject: Re: Magnetic shielding


 Dumb Question #?
 It was asked  in reference to magnetic spacecraft shielding `can it operate
if the object is moving relatively fast?'
  Let's see, a moving magnetic field produces a current. So, if you have such
a shielded spacecraft in a stellar or planetary magnetosphere what happens?

UUCP: {amdahl!bungia, uunet!rosevax, chinet, killer}!orbit!pnet51!schaper
ARPA: crash!orbit!pnet51![e-mail]
INET: [e-mail]

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

Date: 2 Nov 89 18:39:55 GMT
From: cs.utexas.edu!samsung!mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Fragile Space Shuttle

In article <[e-mail]> [e-mail] (Nutsy Fagen) writes:
>
>        Okay, another question for you.  Every time the shuttle goes up or
>comes down, I read about how just about every system is checked, removed,
>replaced, etc.  I can understand a thorough checkout, and the fact that
>space travel is, to say the least, a risky business, but how much of what
>NASA does for turnaround would be considered unneccesary in 10-15 years
>(Provided the same shuttle design is still running).

Probably not very much.  The hardware simply is not designed for airline-type
operations, and NASA has no concept of how to operate that way anyway.

>        As I said before, I agree that such stringent measures are required
>at our current level of knowledge with space travel...

Many people would debate this.  The problem is not with knowledge or
technology, but with the way they are being applied by the people doing
launch systems right now.  People like Max Hunter (designer of the Delta,
nee Thor) say quite firmly that you can't expect easily-reusable systems,
ever, from people who think of spacecraft in terms of missiles rather
than airliners.
--
A bit of tolerance is worth a  |     Henry Spencer at U of Toronto Zoology
megabyte of flaming.           | uunet!attcan!utzoo!henry [e-mail]

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

Date: 2 Nov 89 16:11:36 GMT
From: cs.utexas.edu!wuarchive!texbell!texsun!pollux!attctc![e-mail]  (Lance Franklin)
Subject: Re: Moon Colonies / Ant Tanks?

In article <[e-mail]> [e-mail] (Tom Neff) writes:
>Oh by the way, if you have to burrow underground to survive in a
>Moon colony, why bother to go?  Why not just build underground
>colonies here?  Sure is easier to ship stuff here.  If you have
>to spend your whole life in the basement, how much does it matter
>which basement?


How deep would you have to dig to get 1/6th earth gravity?  :-)



Lance


--
+-------------------------+ +------------------------------------------+
| Lance T Franklin        | | "And all who heard should see them there,
| [e-mail] | |  And all should cry, Beware!  Beware!
+-------------------------+ +  His flashing eyes, his floating hair!"

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

Date: 1 Nov 89 21:51:00 GMT
From: snorkelwacker!spdcc!ima!mirror!frog![e-mail]  (John Woods)
Subject: Re: Manned Jupiter Mission (was Re:

In article <[e-mail]>, [e-mail] writes:
> IMHO, and I believe other's opinions, is that one of the greatest challenges of
> even a manned trip to Mars is that of radiation shielding from cosmic
> radiation.

True, but the engineers noodling around with designs actually know about this.
As I understand it, the scheme they've settle on for a Mars trip is basically
a standard vehicle with a small, well-shielded chamber inside.  When they
detect a solar flare, everyone piles into the shielded chamber and rides
it out.  (The light arrives well before the particles; they'll just have to
put up with the X-rays, I guess)  The total radiation dose planned for the
trip is just barely under NASA's lifetime exposure limit, so nobody gets to
ride the trip twice (as if that were a concern :-( ).  Something to be
concerned about, sure, but not *likely* to be fatal.
--
John Woods, Charles River Data Systems, Framingham MA 508-626-1101
...!decvax!frog!john, [e-mail], ...!mit-eddie!jfw, [e-mail]

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

Date: 3 Nov 89 05:59:46 GMT
From: cs.washington.edu![e-mail]  (Daniel Kerns)
Subject: Re: a glimpse behind Venus's veil (really Science)

In article <[e-mail]> [e-mail] (Michael McNeil) writes:

   Avid tourists of the Solar System won't want to miss the geological tour
   of a portion of Venus's surface that's included in the 20 October 1989
   article in *Science* "Styles of Volcanism on Venus: New Arecibo High
   Resolution Radar Data."  ...

   (And how about this -- in only one week, not only a tour of Venus, but
   another brilliantly lucid [IMHO] article "The Chemistry of Solid-State
   Electronics," by E. Yablonovitch -- and an honorable mention: "Burgess
   Shale Faunas and the Cambrian Explosion."  Sock it to me, oh "National
   Enquirer" of *Science*!  Week after week; I can take it!  "Ahhh...!!!")

Speaking about Science, I am surprised no one mentioned "Would it Be Mars
Without NASA?" on page 329 of the same issue.  Where they say:

    The National Space Council, headed by Vice President Quayle,
    has been wondering whether the management of Bush's Moon-Mars
    initiative ought to be vested in some other organization, such
    as Los Alamos National Laboratory."

They go on to suggest that if "peace really does break out, and if Star
Wars becomes a distant memory, then weapons labs like Los Alamos and
Livermore are going to be desperate for something to do."
--
                Dan Kerns    [e-mail]
                Univ. of Washingtonm Computer Science

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

Date: 3 Nov 89 06:47:09 GMT
From: cs.utexas.edu!mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Manned Jupiter Mission (was Re: Condensed CANOPUS - August 1989)

In article <[e-mail]> [e-mail] (Kevin Bagley) writes:
>One of the major problems with a manned Jupiter mission would be the
>general scope of the mission...  This would greatly complicate such a
>mission since we would need to provide multiple use landing craft and
>the required fuel for operating them...

A good point.  This is, actually, another reason for wanting better
propulsion.  As Arthur C. Clarke was (I think) the first to point out,
Jupiter's gravity well is so deep that getting around in it is really
quite expensive.
--
A bit of tolerance is worth a  |     Henry Spencer at U of Toronto Zoology
megabyte of flaming.           | uunet!attcan!utzoo!henry [e-mail]

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

Date: 3 Nov 89 17:59:03 GMT
From: rochester![e-mail]  (Paul Dietz)
Subject: Re: PowerSat Options

In article <[e-mail]> [e-mail] (bill davidsen) writes:
>In article <[e-mail]>, [e-mail] (Paul Dietz) writes:
>
>|  Jeez.  The microwave beam has low power density because it is
>|  diffraction limited (if it wasn't, we've made the transmitter too
>|  big).  You want a failsafe system to guarantee the laws of physics are
>|  not violated?
>
>  As I have mentioned before, the twit on the street doesn't care about
>the laws of physics, he doesn't want to have anything which sounds like
>atomic, nuclear, or radiation. That why the NMR system was a flop, and
>MRI is great. Same device, but "Nuclear Magnetic Resonance" is *scarey*
>and "Magnetic Resonance Imaging" isn't. People really had exploratory
>surgery because they were afraid of it.
>
>  Now if you tell him that you are going to put a microwave in the sky,
>and it's "two million time more powerful than your home microwave oven,"
>and that it's safe by the laws of physics... I would rather add a
>percent to the cost and be sure that the beam can never be pointed at a
>populated area, than to try and convince people that it won't hurt.

If you look back in this mailing list, you will see we were debating
the question "can a powersat be used as a practical power source for
orbiting beam weapons (that are separate from the powersat)", not
"would a powersat cause hysteria among the public", nor "could the
beam be directed at a city".

The failsafe your message indicated you wanted was one to prevent the
power density from becoming too large.  Perhaps you misremembered or
misread those messages, but please don't try to misrepresent what I
said.

    Paul F. Dietz
    [e-mail]

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

Date: 3 Nov 89 21:41:10 GMT
From: att!cbnewsl![e-mail]  (Stuart Warmink)
Subject: Re: Voyager/Galileo Camera function

(Fred Kokaska) writes:
> Can the cameras on the Voyager and Galileo spacecrafts be aimed back at
> the spacecrafts themselves?  Can you imagine a Voyager scrapbook? "Here's
> me in front of Saturn!" |-)  It might also show some of the speculated
> impact damage.

Even if the cameras could be pointed in such a fashion, the picture would be
hopelessly out of focus...the depth of field of telelens cameras, especially
with large aperatures, is very limited. Don't forget that the lenses are
focussed at "infinity".
--
------------------------------------------------------------------------------
Stuart Warmink, Whippany, NJ, USA  |  [e-mail]  |  Pretentious? Moi?
-------------------------> My opinions are just that <------------------------

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

Date: 4 Nov 89 03:08:43 GMT
From: norge![e-mail]  (John McKernan)
Subject: Re: Moon Colonies / Ant Tanks?

In article <[e-mail]> [e-mail] (daniel mocsny) writes:
>Previous emigrations from one part of the earth to another are nothing
>at all like potential emigrations to the Moon.
 [reasonable artical saying we will probably go into space eventually deleted]

In a larger sense man's mass migration into space is exactly like his
migration to other parts of the Earth. Whenever it was possible to move to
an area with new resources to exploit, we have moved there and exploited
those resources. Once it is possible for mankind to move in large numbers
into space, all of man's history shows that it is inevitable that man
will do so.

John L. McKernan.                                                  [e-mail]
Disclaimer: These are my opinions but, shockingly enough, not necessarily Sun's
-------------------------------------------------------------------------------
The future is rude and pushy. It won't wait for us to solve today's problems
before it butts in with tomorrow's.

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

Date: 3 Nov 89 16:29:07 GMT
From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Voyager/Galileo Camera function

In article <[e-mail]> [e-mail] (Fred Kokaska) writes:
>Can the cameras on the Voyager and Galileo spacecrafts be aimed back at
>the spacecrafts themselves? ...

Galileo I'm not sure about.  Voyager's cameras are on the end of a boom
and certainly can be aimed at some parts of the spacecraft -- there are
camera-calibration targets on a cooling fin.
--
A bit of tolerance is worth a  |     Henry Spencer at U of Toronto Zoology
megabyte of flaming.           | uunet!attcan!utzoo!henry [e-mail]

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

Date: 3 Nov 89 18:53:27 GMT
From: ncis.tis.llnl.gov!blackbird![e-mail]  (News System Account)
Subject: Re: Wood in space

In article <[e-mail]> [e-mail] (Will Martin) writes:
> deleted material
>ski poles work in soft snow?  Anyway, that started me thinking -- what
>would happen to wood exposed to space?  Consider the effects of vacuum,
>temperature, and radiation from the sun -- would wood dry up, crumble,
>and disintegrate in a matter of seconds or minutes, or would it remain
>strong enough to use for a reasonable length of time?
>
>Was any wood put on the LDEF? Maybe some of the instruments there should
>have had a nice Victorian-style mahogany housing... :-)
>
>Anyone have any ideas on this subject? Maybe we can have some nice teak
>space yachts at some future date...
>
>Regards, Will

In the Air Force Museum is a piece of the Wright Bros. first(?)
airplane that went to the moon.  The wood seems to be O.K.
but is encased in glass which precludes close inspection.

***************************************************************
          STANDARD AIR FORCE DISCLAIMER
   These views do not reflect the opinion of the government.
   If the government wanted my views, it would ask for them.

   Capt Stuart Sheldon
   AFIT/ENA Box 4209              [phone]
   WPAFB  OH 45433                AV785-6460
   [e-mail]    [e-mail]
****************************************************************

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

Date: 4 Nov 89 04:03:18 GMT
From: agate!sandstorm.Berkeley.EDU![e-mail]  (George William Herbert)
Subject: Re: Moon Colonies / Ant Tanks?

In article <[e-mail]> [e-mail] writes:
>
>From what I learnt from school, I recall that the gravitational force
>is inversely proportional to the distance between the center of masses. Hence
>the gravitational force will increase as you go towards the center of the earth.

Nope.  The force is inversely porportional to the distances and directly
porportional to the enclosed mass... anything beyond the distance
of the smaller object has no effect.  You decrease off towards zero-g
within an object, with max. at the surface.


****************************************
George William Herbert  UCB Naval Architecture Dpt. (my god, even on schedule!)
[e-mail] [[e-mail], but i don't check mail often]
----------------------------------------

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End of SPACE Digest V10 #203
*******************