Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V08/V8_319.TXT

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Date: Tue, 9 Aug 88 01:04:44 PDT
From: Ted Anderson <[e-mail]>
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Subject: SPACE Digest V8 #319

SPACE Digest                                      Volume 8 : Issue 319

Today's Topics:
             Re: The Face on Mars
              New oxidizer plant
              Re: Skintight Space Suits
             Re: Libertarian space policy
                Re: What's New
               Re: Solar Sails
            Re: Are these postings useful?
         Re: Time skew -- does it hurt SETI?
        Re: Space Station Name chosen -- Fred
  Re: Automated vs. personned spacecraft -- a reasonable compromise
               Re: Solar Sails
----------------------------------------------------------------------

Date: 1 Aug 88 15:27:13 GMT
From: cfa!cfa250![e-mail]  (Steve Willner P-316 x57123)
Subject: Re: The Face on Mars

From article <[e-mail]>, by
[e-mail] (Fred Baube):
> World Weekly News cover story, August 9:
> "Face On Mars Beams Warning to Earth" (with cover photo)
>
> Named are "Swiss astronomer Ludin Pasche" and "Dr Lars-Tvar
> Carlsson, the noted Swedish astronomer".

Neither of these names is listed in the International Astronomical
Union membership directory dated February 1983 (the latest edition).
--
Steve Willner            Phone [phone]         Bitnet:   willner@cfa
60 Garden St.            FTS:      830-7123           UUCP:   willner@cfa
Cambridge, MA 02138 USA                 Internet: [e-mail]

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

Date:     Mon, 1 Aug 88 12:23:52 CDT
From: Will Martin -- AMXAL-RI <[e-mail]>
Subject:  New oxidizer plant

THe following is from the Washington Post, 28 July 88, p.6:

ROCKET FUEL PLANT WILL RELOCATE

UPI - Salt Lake City, July 27 -- A Nevada chemical company whose rocket fuel
plant was destroyed by an explosion May 4 will rebuild in southern Utah,
officials announced today, saying that the move offers the best chance
of speedy completion.

Pacific Engineering and Production Co., or PEPCON, selected a site about
15 miles west of Cedar City over two Nevada sites considered for the $23
million plant, according to Fred Gibson, PEPCON chief executive officer,
and general counsel Keith Rooker.

"Selection of the Iron County site results from pressing national
requirements for ammonium perchlorate," Rooker said in a joint news
conference with Gov. Norm Bangerter at the state capitol.

The Henderson, NV, plant was one of only two in the nation manufacturing
ammonium perchlorate, which is crucial in all solid-fuel-propelled
missiles and rockets, including space shuttle boosters.
***End of Article***

Comment --I suppose the distinction between "fuel" and "oxidizer" is too
much to ask of the newspapers & wire services... WM

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

Date: Mon,  1 Aug 88 13:04:17 PST
From: Peter Scott <[e-mail]>
Subject: Re: Skintight Space Suits
X-Vms-Mail-To: EXOS%"[e-mail]"
>From:  att!chinet!mcdchg!clyde!watmath!utgpu!utzoo![e-mail]

>(Henry Spencer)

>More generally, I find it really strange that people have to be told, over
>and over again, that the skin-tight-spacesuit idea HAS BEEN TRIED in
>vacuum chambers and IT WORKS.  There seems to be an unlimited supply of
>hypothetical problems that just don't exist in real life.

I'm very interested in reading about actual data where it exists, rather
than speculation.  Where can I find papers on these vacuum chamber
experiments?

Peter Scott ([e-mail])

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

Date: 1 Aug 88 16:10:17 GMT
From: ecsvax![e-mail]  (D Gary Grady)
Subject: Re: Libertarian space policy

In article <[e-mail]> [e-mail] (Leonard Erickson) writes:
>. . . (In case
>you didn't know, the *real* reason that Britain and Argentina
>went to war over the Falklands was that it looks like there may
>be a major oilfield in the South Atlantic and the Falklands are the
>nearest land. Own the Falklands and you own the oil..)

Wrong newsgroup for this, but for the record such conspiracy theories
rarely hold water on close examination.  It's possible that the
cojectured presence of an oil field was a consideration, but anyone
familiar with the politics and history is unlikely to buy it as the
main or "real" reason for the war.  It's most likely that Argentina's
military government invaded thinking the UK would not respond and
hoping to bolster domestic support and get the public's mind off the
lousy domestic situation with respect to human rights and the economy.
Argentina has claimed the Falklands/Malvinas for decades, of course,
long before anyone knew of the possibility of oil there.  Britain's
response was motivated by a mixture of pride and principle, as far as I
can tell, even if you disagree with the principle in question.
Initially, by the way, the Argentine government's move proved
successful; there was a virtual orgy of patriotism in the wake of the
invasion.  After defeat, of course, things went rather to the other
extreme, the rascals were thrown out, and many of them were put on
trial.
--
D Gary Grady
[phone]
USENET:  {seismo,decvax,ihnp4,akgua,etc.}!mcnc!ecsvax!dgary
BITNET:  [e-mail]

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

Date:     Mon, 1 Aug 88 19:21:58 CDT
From: [e-mail] (Allen C. Kistler)
Subject:  Re: What's New

>From: b.gp.cs.cmu.edu![e-mail]  (Ralf Brown)
>
>In article <[e-mail]> [e-mail] (B Gray) writes:
>}TSS-1 will deploy a satellite at the end of a 20km conducting
>}wire with an insulating coating, upwards from the shuttle....
>
>Wasn't there a proposal that this could be used as a low-thrust orbit
>reboost?  The current would flow through the wire, generating a magnetic
>field which interacts with the earth's, and then back via ions in the
>incomplete vacuum of LEO.

In _Journal_of_Geophysical_Research_, vol. 70, p.p. 3131-3145, (1 July 1965)
there is an article which addresses this, so the idea has been around for a
while.  Basically the idea is that as a conducting satellite moves across the
magnetic field, the motionally induced electric field produces a current
through it.  This current drives the production of Alfven waves, a special
kind of plasma wave for the non-EE, non-physicist folks out there.  The energy
for the wave comes from the motion of the satellite, so this represents a form
of drag on the satellite.  The neat thing is that if you apply a big enough
voltage of your own across the satellite to MAKE the current go the OTHER way,
then you get a little bit of boost out of it, rather than drag.  This will
never be more than 50% efficient since you'll still be sending some of the
energy away as plasma waves.  I don't know of any satellites that have ever
actually used this method propulsion, so it may not be an especially practical
method.  Anyone else?

-----------------------------------------------------------------------------
   Disclaimer:  UI isn't responsible for ANYBODY

Allen Kistler   [e-mail]  Internet
                iowasp::kistler                              SPAN
-----------------------------------------------------------------------------

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

Date: 1 Aug 88 21:38:08 GMT
From: grasp.cis.upenn.edu![e-mail]  (Nathan Ulrich)
Subject: Re: Solar Sails

In article <[e-mail]> [e-mail] (Steve Abrams) writes:
>    The physical process is (loosely) that the photon is "absorbed" by an
>atom in the sail film.  The energy is used to raise an electron's energy level.
>That electron then spontaneously decays thereby emitting another photon *with
>the same energy* as the original photon but in the opposite direction.  In each
>process of absorption and re-emission, momentum is transferred in the same
>direction to the sail film.  The energy of the photon doesn't change (a scalar
>quantity) and the magnitude of the velocity of the photon doesn't change *BUT*
>the direction changes.  By Newton's Third Law (Action/Reaction), momentum is
>transferred to the sail from the photon.
>
>    I realize that this won't satisfy purists, but it should be sufficient
>for someone with a poor physics background.

I don't know if I am a purist, but it won't satisfy me.

One indisputable law of the universe, "You can't get something for nothing."
Your explanation above will result in an increase in the total mass-energy
of your system.

The vector sum of the momentum of two spaceships moving at 10000 m/s in
opposite directions is zero.  This doesn't mean the energy is the same as
two spaceships with "zero" velocity.


Nathan Ulrich
[e-mail]

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

Date: 1 Aug 88 16:00:40 GMT
From: phri!cooper!dasys1![e-mail]  (Tom Neff)
Subject: Re: Are these postings useful?

In article <[e-mail]> [e-mail] (Jordan Brown) writes:
>In article <[e-mail]> [e-mail] (Tom Neff) writes:
>>The only thing I could sincerely do without is "catching up" on 2+
>>month old AvWeek issues.
>
>Take heart, Henry - I think your AvWeek digests are one of the greatest
>things since the airplane... they're one of the few ways I keep in touch
>with what's happening in aviation & space technology & politics.

I did NOT mean to imply that Henry's work was unappreciated!  I like the
Avweek summaries too.  But if he is behind, it would be worth it to
skip forward a few so the digests are more timely.  That's all I meant.






--
Tom Neff            UUCP: ...!cmcl2!phri!dasys1!tneff
    "None of your toys    CIS: 76556,2536           MCI: TNEFF
     will function..."    GEnie: TOMNEFF           BIX: t.neff (no kidding)

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

Date: 1 Aug 88 15:47:55 GMT
From: phri!cooper!dasys1![e-mail]  (Tom Neff)
Subject: Re: Time skew -- does it hurt SETI?

In article <[e-mail]> [e-mail] (Mike Coffin) writes:
>A point that hasn't been made: even if electromagnetic radiation is
>the last word in communication, why spray most of the power into empty
>space?  I would think that advanced civilizations would probably use
>modulated lasers or some other point-to-point method of communicating.
>Not only would this save power, but it doesn't pollute the
>electromagnetic spectrum.  That would make detection on earth a pretty
>low probability event --- we would have to me almost exactly in the
>right place at the right time to detect anything at all, and if we
>*did* it would probably be a brief, unrepeated message.

(1) You're talking about interplanetary communication channels dedicated
to a civilization's own parochial purposes, not a beacon designed for
detection by other civilizations.  If we suppose that an advanced
civilization would want to be seen, and have the resources to do it,
I can think of nothing better than a big radio "lighthouse" broadcasting
on you-know-what frequency, and presumably not interfering at all with the
more sophisticated bands it uses for its own work.

(2) If we did happen to catch one -- not impossible if many systems
existed using this method, each linked to many other systems -- why would
it be a "brief, repeated" message?  I would imagine it would be a continuous
Niagara of information, like tapping into SpaceLAN.

A bigger problem is what to do if everyone is just beaming at what THEY
think are the likely near systems, rather than "spraying" as you put it
so that the distant long-shots can pick it up.
--
Tom Neff            UUCP: ...!cmcl2!phri!dasys1!tneff
    "None of your toys    CIS: 76556,2536           MCI: TNEFF
     will function..."    GEnie: TOMNEFF           BIX: t.neff (no kidding)

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

Date: 31 Jul 88 18:02:23 GMT
From: mcvax!unido!ecrcvax![e-mail]  (John Gregor)
Subject: Re: Space Station Name chosen -- Fred

>President Reagan last week named the NASA/International
>space station "Freedom".
                ^^^ ^

Well, it's the closest thing to a compromise that I've ever seen from
the U.S. Gov. ;-)
--

John Gregor                                       [e-mail]

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

Date: 1 Aug 88 18:57:11 GMT
From: ihnp4!ihlpl![e-mail]  (Knudsen)
Subject: Re: Automated vs. personned spacecraft -- a reasonable compromise

In article <[e-mail]>, [e-mail] (Will Martin -- AMXAL-RI) writes:
> There is an obvious middle ground. This is not my original idea -- it has
> been standard in SF for decades. You send a human brain, interfaced to the
> mechanisms, and do not waste space and mass on all the gorp required to
> support a full human body. Up until recently, that was just "pie in the
> sky" wishful thinking, but, as researchers progress more and more on
> viable interfaces for prosthetic devices and sensors, it becomes a
> reasonable way to get human thinking ability integrated on a real-time
> basis with automated deep-space probes. Carrying only the oxygen,
> fluids, and nutrients to support the few pounds of brain tissue, and,
> ideally, equipped with nanotechnology repair units to fix up radiation
> damage and wearing-out biological elements, a human brain with a
> spaceship body could not only explore the solar system and Oort cloud,
> but reach the stars. The lifetime of this synergy could be centuries,
> since all the non-neurological toxin-producing parts of the body would
> be gone, and longer-lived and replaceable mechanical parts would provide
> the support functions.
>
> Regards, Will Martin

First let me say that I had fantasized stories based on doing this
for people whose bodies were dying untimely deaths -- put their
mind/soul into a spacecraft.  The ultimate sports car, an extension
of its driver.  I like the concept, but it has lots of
flaws--
(1) People, especially governments, will never buy it in our lifetime
(too gruesome).  The required advances (?) in ethics will take
generations.

(2) For foreseeable future, the equipment needed to synthesize and
purify and pump the life-support chemicals (ie, blood and O2 etc.)
is likely to be both bulkier and less reliable than a human body.
[You could streamline ahuman body by amputating the arms and legs,
if your volunteer was already a quadraplegic].
Seriously, we could probably do a lot more research into high-efficiency
foodstuffs that eliminate the need for elimination or
recycle efficiently.  That is, use your proposed biochemical
technology to synthesize foods in space for conventional people.

(3) While many vital organs do fail on people prematurely
(hearts, eyes, cancer), the brain has life limits too.
Most elderly people are unable to learn new memories.
Brain cells DO NOT divide and reproduce -- when they're gone,
they're gone.  So much for your centuries of lifespan.

(4) Until we get warp drive or hyperspace, space travel is
going to be pretty damn DULL 99.9% of the time, just waiting
to get to the next thing worth seeing.  Human brains do not
like being deprived of new sensations for years and then
suddenly being expected to deal with a planetary rendezvous.
Granted, suspended animation (a la 2001) may be cheaper for
just a brain than for a whole person.

(5) Boredom, loneliness, uncertainty -- ever hear of this
software bug called insanity?  Don't put any weapons or too much
plutonium fule on the first few ships...

(6) What would be the legal rights of a person-ship?
OK, they can build a newer vessel and move your brain into it.
But what happens when the new crop of younger brains trained
in newer methods starts taking over the plum exploratory missions,
and you get relegated to dull but dangerous milk-runs where the
beaurocrats secretly hope you'll buy the farm?
A gold mine here for SF authors -- have they worked it yet?
(Really, I'd like titles and authors for my own enjoyment.)
A very early Frank Herbert (Destination: Void) novel hooked
up three brains to a deep-space ship, but they all died
from sensory overload, which personally I doubt.

(7) My body has to be pretty bad before I'll consider giving it up.
I mean racked with pain or totally useless.
I wonder if the human psyche could really stay sane once divorced
from its original body, even if the new one seemed to offer
valid replacements of all functions and pleasures.

I'll be looking (hoping?) for some refutations of the above.

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

Date: 2 Aug 88 03:51:46 GMT
From: agate!saturn!ucscb.UCSC.EDU![e-mail]  (Space Cadet)
Subject: Re: Solar Sails

In article <[e-mail]> [e-mail] (Nathan Ulrich) writes:
+In article <[e-mail]> [e-mail] (Steve Abrams) writes:
+>The energy of the photon doesn't change (a scalar
+>quantity) and the magnitude of the velocity of the photon doesn't change *BUT*
+>the direction changes.  By Newton's Third Law (Action/Reaction), momentum is
+>transferred to the sail from the photon.
+
+I don't know if I am a purist, but it won't satisfy me.
+
+One indisputable law of the universe, "You can't get something for nothing."
+Your explanation above will result in an increase in the total mass-energy
+of your system.

Surely the frequency of the photon as reflected from the sail will be
lower than the original photon (thus it will have lower energy)?
It sounds to me like there would be a double Doppler effect (once upon
absorbtion, and once upen emmision).
--
> John H. DuBois III # [e-mail]  ...!ucbvax!ucscc!ucscb!spcecdt <

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

End of SPACE Digest V8 #319
*******************