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Date: Sun, 20 Sep 92 05:00:14
From: Space Digest maintainer <digests@isu.isunet.edu>
Reply-To: Space-request@isu.isunet.edu
Subject: Space Digest V15 #224
To: Space Digest Readers
Precedence: bulk
Space Digest Sun, 20 Sep 92 Volume 15 : Issue 224
Today's Topics:
AIA/AIAA
Ethics
Ethics, again. (2 msgs)
How to build ion engine? [ A REPLY ]
Hubble's constant
Ion for Pluto Direct
Life not Death through Space Exploration (Was Re: Population Fascism!)
Looking for database of stars with their position in the sky
New Information Source
Pluto Direct Propulsion Options
Property rights (was Terraforming needs to begin now)
Shuttle Replacement (was: One Small Step...)
Solar radiation and astronauts (2 msgs)
Space Platforms (political, not physical : -)
Welcome to the Space Digest!! Please send your messages to
"space@isu.isunet.edu", and (un)subscription requests of the form
"Subscribe Space <your name>" to one of these addresses: listserv@uga
(BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle
(THENET), or space-REQUEST@isu.isunet.edu (Internet).
----------------------------------------------------------------------
Date: 18 Sep 92 23:55:44
From: Wales.Larrison@ofa123.fidonet.org
Subject: AIA/AIAA
Newsgroups: sci.space
Michael V. Kent writes
>>NASA Administrator Daniel Goldin will be the keynote speaker at a
>>luncheon being held in Washington today of the Aerospace
>>Industries Association of America.
>The Aerospace Industries Association of America??? It was a good
>try, but whoever writes these things should really have an acronym
>list handy. AIAA = American Institute of Aeronautics and
>Astronautics.
>Of course if there are two aerospace societies with the initials
>AIAA, I've just made a fool of myself on an international network.
>But I'm not worried.
Chuckle. You sure came close. There is an "Aerospace
Industries Association of America" headquartered in the Washington
DC area. It's primarily an industry organization, and publishes
lots of statistical data on the status of the US aerospace industry.
Among other things, their head is a member of the National Space
Council Advisory Panel.
However, it's commonly abbreviated AIA, and the Goldin talk was
at an AIAA meeting. So your comment is correct regarding the mis-
speaking of the NASA press release.
------------------------------------------------------------------
Wales Larrison Space Technology Investor
--- Maximus 2.00
------------------------------
Date: Fri, 18 Sep 92 19:53:27 BST
From: amon@elegabalus.cs.qub.ac.uk
Subject: Ethics
> Again, I can't 'prove' that life is good. Maybe it's not. I'm a little
> biased on the subject, having been alive for as long as I could think about
> it. But, I can show why your ultimate premise contradicts your life. As
> long as you think that terra-forming Mars is bad, you think life is bad.
> So what? I don't care if you want to spend several decades preserving
> something you don't like. Seems like just desserts for someone with
> such a silly attitude.
>
This is getting interesting :-)
Just to throw in a friendly monkey wrench:
I value knowledge. The understanding of the origin of life on Earth requires not
Earth based fossils, but fossils of other possible forms from other places, and
possibly (and even more informative) living examples of alternate, or maybe not
so alternate forms of life.
Since it is of value to humans to understand their own origins, protecting the
Martian life and studying it is in human interests, possibly even more so than
the loss of a bunch of Earth based species with the same old DNA. (Bor...ing!)
Thus destruction of the Martian life prior to studying it is anti-human, and
thus anti-life.
Well, I happen to agree with Terraforming. But the logic of understanding the
Mars is strong. I just don't think the two are necessarily incompatible. We
aren't going to start terra forming Mars tomorrow. Probably won't be considered
until we've been their for quite awhile. So there will be time to look around
and if necessary, take measures to preserve samples of the indigenous life for
study.
> As long as we're going hypothetical, maybe that Martians did introduce life,
> killing whatever WAS here, and we evolved from what they left, long after
> their planet died. So, the point being, hypotheticals like the above are
>
Although Paleontology and DNA studies are pushing the frontiers back and gaining
better understanding of early life, one could still not absolutely rule out that
all present life on Earth is descended from the porta-potty dump on a lifeless
appearing land surface by a random passing starship. How life starts is really
pretty irrelevant in the long run. If there was anything there before the dump,
I hope they took samples for study...but I'm glad they didn't moralize about the
privy because otherwise we (and I in particular) would not be here. Maybe there
wouldn't even be intelligent life here at all... And, no, I'm not advocating
that this did happen. It is just a thought experiment, a point of debate...
------------------------------
Date: 19 Sep 92 18:21:59 GMT
From: Josh 'K' Hopkins <jbh55289@uxa.cso.uiuc.edu>
Subject: Ethics, again.
Newsgroups: sci.space
18084TM@msu.edu (Tom) writes:
[Miscellaneuos ravings on the morality of raper, murder, overpopulation and
going to the bathroom deleted]
>The point is that you are a fascist, since you have intellectually set
>yourself as the pinnacle of all human life, with sole power to decide
>right/wrong, good/bad, and a host of other principles that translate
>into 'who get's controlled, and how'.
I stumbled over this one twice before I broke out laughing. To the best of my
knowledge, the author is the same person who, despite our protestations, has
decided that terraforming Mars is defined to be good, and we can't possibly
dissagree unless our adress includes the numbers 666. Does this mean that Tom
is a Facist? Naw, we'll find out next week that "sole power to decide right and
wrong" doesn't apply in this case.
--
Josh Hopkins "I believe that there are moments in history when
challenges occur of such a compelling nature that to
miss them is to miss the whole meaning of an epoch.
jbh55289@uxa.cso.uiuc.edu Space is such a challenge" - James A. Michener
------------------------------
Date: Sat, 19 Sep 92 22:17:19 GMT
From: "Thomas H. Kunich" <tomk@netcom.com>
Subject: Ethics, again.
Newsgroups: sci.space
In article <Busn2M.99u.1@cs.cmu.edu> 18084TM@msu.edu (Tom) writes:
>
>Keep in mind, you non-self-interested person, that not only do you LIE,
>since it is IMPOSSIBLE for ANY HUMAN to act self-lessly, without coercion,
>but the worst of all dictators are those that do things out of 'non-
>self-interest'. At least the admitted evil ones have a concience to
>stop them when their anti-life practices get particularly evil.
I wonder if Mother Teresa would agree with you? I knew a guy that
was down to his last dollar, a bum asked him for some money and he
took the guy into a cafeteria in NYC and split whatever they could get
for the buck. Maybe this guy was afraid the bum would attack him if he didn't
pay up?
How many parents would give their lives for their children? How many soldiers
have died for their countries?
Selfless acts of courage aren't rare at all. They occur every single day. They
are happening all around you. Too bad that you have your blinders on.
You might see something rather unique about human beings.
------------------------------
Date: 13 Sep 92 03:49:17 GMT
From: "Steve J. Quest" <iowegia!quest>
Subject: How to build ion engine? [ A REPLY ]
Newsgroups: sci.space
ron@vicorp.com (Ron Peterson) writes:
>
> Could someone please describe to me how to build a practical ion rocket
> engine?
>
> I'd like to know if it would be possible to build a micro-sized
> platform that could lift itself in the air powered by a solar cell
> or very small battery. I thought that perhaps a tiny ion motor
> with a solar cell painted on its exterior might be capable of
> lifting itself off the ground.
> ron@vicorp.com or uunet!vicorp!ron
>
Ron,
It would be impossible for an ion engine to lift the
weight of silicon solar cells. There is very little thrust from
ion engines. Although the thrust is weak, the velocity is
GREAT, and they may one day be used for interplanetary travel.
I can detail for you a voltage multiplier which could be
used to "drive" a model ion engine. It is a simple configuration
using cheap si rectifiers and ceramic capacitors.............sq
(The engine would be a metal pin with a very sharp point. The
ions will leap off the point causing the engine to move a bit if
it is suspended by a fine wire feeding the HV to the point....)
------------------------------
Date: Sat, 19 Sep 92 19:01:56 EDT
From: Michael Robert Williams <mrw9e@kelvin.seas.Virginia.EDU>
Subject: Hubble's constant
Newsgroups: sci.space
I did not read the article in question, but I can say a few things
References: <1992Sep16.152541.1@ewsvax.mdcbbs.com>
Date: Sat, 19 Sep 1992 22:08:19 GMT
Lines: 5
-Mike Williams
-mrw9e@virginia.edu
------------------------------
Date: Sat, 19 Sep 1992 21:07:31 GMT
From: Dave Tholen <tholen@galileo.ifa.hawaii.edu>
Subject: Ion for Pluto Direct
Newsgroups: sci.space
Phil G. Fraering writes:
> Dave Tholen writes:
>
> \The current Pluto flyby mission design calls for chemical rockets and NO
> /Jupiter flyby, and the flight time is about seven years. Your posting seems
> \to be claiming that an ion drive can place twice the payload into orbit around
> /Pluto with a flight time of about 3.5 years. If this were true, I'm quite
> \certain that the Outer Planets Science Working Group would have heard of it.
>
> "If it were better, we would have considered it."
Is this intended to be a paraphrasing of my posting? If so, this is quite
incorrect. We are constantly getting ideas from people who can make the
Pluto mission "better", but most of those ideas involve the addition of
instruments that can make measurements that none of the other instruments
can make. Unfortunately, such additions also involve added cost, and we
simply can't afford a Cadillac mission to Pluto. The overriding concern is
whether the mission design that we have is good enough to make doing it
worthwhile. There are always ways to make it better, but unless such ideas
can make it cheaper as well, they are unlikely to get very far. We live in
a cost constrained world, and if you think you can come up with a better
mission for the same amount of money, then submit a proposal to NASA.
> I don't want "because". I want the real reasons...
Try me again once more, with clarity. To be literal, the word "because"
didn't appear in the posting above. And the real reason ought to be
obvious: money, money, money. If you think enough folks out there are
willing to contribute money out of their pockets to finance a better Pluto
mission, maybe we should set up something like the Planetary Society or
the National Space Society and try to raise enough money to add those
extra instruments, or fund the development of an appropriate ion drive
(note that the station-keeping ion drives are not appropriate for this
mission).
------------------------------
Date: 19 Sep 92 18:46:00 GMT
From: wingo%cspara.decnet@Fedex.Msfc.Nasa.Gov
Subject: Life not Death through Space Exploration (Was Re: Population Fascism!)
Newsgroups: sci.space
In article <gdavis.716823126@griffin>, gdavis@griffin.uvm.edu (Gary Davis) writes...
>
> Why are those folks who would find the Earth a much more attractive\
>place to live with fewer people characterized as population fascists?
>Its clear that the carrying capacity of this planet is finite and that
>the joys of living for many of us come from open spaces,intact forests,
>clear and natural areas and so forth.
No one is arguing that a world with a smaller number of people is by
definition bad. We all like an uncluttered unpolluted world. The problem
is that every single proposal that is put forth to "control" population is
based upon involuntary methods "execept for the space option". It has been
shown based upon the five thousand year history of so called civilized man,
that when one group decides the fate of another group, invariably this decends
into what the Russians called the "Nomnecletura" (spelling). This means
the deciders decide to ignore the rules they put on the ones that they are
deciding their lives for. It is manifested in the west by the "cultural elite"
who think they know what is best for us and why don't we just listen to them.
This form of decision making as it relates to population would mean the ending
of families and nations. Who would decide how many people should be allowed to
live in India for example? What would be their adgenda. Would it be the
"enlightened west" that makes the decisions? Of course not there would be a war
like never in history. No one doubts that India needs to control its population
but who is going to do it for them? No one without a war to force it. Some
readers of this will think that I am taking this logic too far but ask a person
in an overpopulated nation what they think about it, you might be surprised at
how little they think of your enlightened approach.
>Most religions teach that man is the most important creature in the
>entire Universe. This to me is the upmost in hubritic none sense.
>
>And Oh, yes... I suppose if God had not wanted so many people on this
>planet,why did he make so many of them?
>
>That reminds me of a population discussion I had with a former student
>of mine. When I asked him how many children would make an ideal family
>he gushed," just as many a Jesus will send us".
>When asked about population concerns he responded," God would not let
>this planet become over populated."
>
>That iditoic attitude is shared by most devote religions including those
>in the USA!
I take offense at this attitude. Do I smear all scientist because of the nuts
on here that talk of gravity suspending spaceships and the like? Most
Christians do not have this attitude. Especially the Protestant ones. Do not
lump all people who believe in a supreme deity into a little box that you can
then dismiss from your "enlightened" perspective.
>Also I understand from a graduate student who was expelled from Islamic
>Iran that women are treated with respect in and only to the extent that
>they maintain their status as baby machines.
This is part of the reason that any plan to "control" the earths population is
doomed to failure because your plan would meet the fanatical resistance of
these people especially.
>The schools are so jammed that they run split sessions well into the evening.
>Ah yes, that we all could bask in such religious bless that God's in
>his heavan and alls right with the planet.
>
It is evident from your post that you have a very anti-religious bias. Well
you are entitled to that opinion. You must realize that any plan to reduce the
world's population cannot be based upon force. It must be based upon that most
insdious of means, increased wealth. In every civilization in history the
only effective means of long term population control has been the acquistion of
wealth. From Egypt to Greece and Rome in ancient times to Europe and America
and Japan today this is true. We must increase the available wealth to these
nations of the world without just giving it to them. It must come about in the
general increase of available planetary wealth. How is this to happen? By the
advance of mankind into space where the resources that await us are greater
by several orders of magnitude than what is available on earth. This is the
ultimate justification of the space program, just as the age of exploration that
opened 500 years ago was based upon creating more wealth for Europe.
There are those on this net, most of you in fact, that believe that we will do
this in fifty or one hundred years. My friends this timeframe is too long, we
must begin today or we will slip into the slick arguments like the one that
started this post and the slick Willie's and the Gore's and Ted Turner's of
the world that will appeal to the vanity of the elite to push their agenda. It
is interesting that Slick Willy, in comments that he made while at a fund raiser
in LA this past week confessed to always wanting to be "part of the cultural
elite".
In case someone would post that I am bashing the elite, I am not. I do bash the
tendency of that elite to want to tell us what is good for us and that why can't
we see it like they in their enlighted position do? The elite of the world
have a responsibility to their lesser fortunate bretheren. That responsibilty
is not that of a lord telling us how to live, but that of a servant helping us
to attain a greater height ourselves. Great wealth, intellect and position mean
nothing if it is not used for the good of all. This is why the space program is
so crucially important. It can be the act of the intellectual and cultural
elite to open the last frontier for all mankind that will enable all mankind
to rise to a level of wealth and intellect that will allow them to CHOOSE to
reduce their birthrate of their own violition.
This sir is why your view is considered cultural facism. Facism is the rule of
the few over the many "for their own good". It brought about the death's of
26 million people from 1933 to 1945 becaue the ones that would have "benefited"
from the enlightend rulership of the "New Order" did not agree to be ruled
over, especially after the elite that was doing the ruling decided that the
population would be better served by the elimination of those who did not, in
their opinion, deserve to live on the earth.
I have endeavored not to answer this in a flame but with reason. This attitude
must not be allowed to gain ascendancy in the world, which it has the potential
of doing for obvious reasons.
Dennis, University of Alabama in Huntsville
^A^A^A^A
From isu@VACATION.VENARI.CS.CMU.EDU Sat Sep 19 16:51:17 1992
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Xref: crabapple.srv.cs.cmu.edu sci.space:48653 talk.politics.space:1635 alt.politics.libertarian:259
Path: crabapple.srv.cs.cmu.edu!cantaloupe.srv.cs.cmu.edu!das-news.harvard.edu!ogicse!mintaka.lcs.mit.edu!ai-lab!life!isbell
From: Charles L Isbell <isbell@ai.mit.edu>
Newsgroups: sci.space,talk.politics.space,alt.politics.libertarian
Subject: Re: Space Platforms (political, not physical : -)
Message-Id: <ISBELL.92Sep19161338@panther.ai.mit.edu>
Date: 19 Sep 92 20:13:38 GMT
Article-I.D.: panther.ISBELL.92Sep19161338
References: <1992Sep16.054900.17022@techbook.com>
<16SEP199214185404@nssdca.gsfc.nasa.gov>
<STEINLY.92Sep16135652@topaz.ucsc.edu>
<1992Sep17.165755.12139@ucsu.Colorado.EDU>
<STEINLY.92Sep17143018@topaz.ucsc.edu>
<1992Sep18.183806.28687@mnemosyne.cs.du.edu>
Sender: news@ai.mit.edu
Followup-To: sci.space
Organization: MIT Artificial Intelligence Laboratory
Lines: 21
In-Reply-To: smcguire@nyx.cs.du.edu's message of 18 Sep 92 18:38:06 GMT
Source-Info: Sender is really news@CRABAPPLE.SRV.CS.CMU.EDU
Source-Info: Sender is really isu@VACATION.VENARI.CS.CMU.EDU
smcguire@nyx.cs.du.edu (Scott McGuire) writes:
|If I own some frequency (in some limited area I imagine) no one can use
|that frequency with out my consent. If they do they are trespassing and
|subject to whatever civil/criminal penalties the law allows. It doesn't
|matter how tiny my transmitter is (or even if I transmit at all). Also,
|if I broadcast with to strong a transmitter and interfere with someones
|frequency in a neighboring area, than I am trespassing.
But how did you come to own it in the first place?
--
Peace.
"If you stick a knife nine inches into my back and pull it out three inches,
that is not progress. Even if you pull it all the way out, that is not
progress. Progress is healing the wound, and America hasn't even begun to
pull out the knife."
-Malcolm X
-\--/-
Don't just adopt opinions | \/ | Some of you are homeboys
develop them. | /\ | but only I am The Homeboy From hell
-/--\-
------------------------------
Date: 19 Sep 92 23:51:37 GMT
From: David Drum <david@MEDUNA.CS.MISSOURI.EDU>
Subject: Looking for database of stars with their position in the sky
Newsgroups: sci.space
Hi all,
I'm hacking the code to a ray tracer that I have so that if it determines
that the ray hits 'sky' it figures out where in the sky it is looking and
looks up in a database to see if there is a star there. I need the database,
though, with magnitudes and positions in polar coordinates, preferably with
Polaris at 0,0 or 0,pi/2. I think I have those right; maybe some kind soul
would straighten me out on that also. I guess if theta is equatorial and
make that longitude and phi
is latitude, then if vertical is phi = pi/2, theta would have no meaning.
But I digress. If anyone can point me to a file with a few thousand stars,
ASCII format (it will wind up on a NeXT), I'd be superbly greatful. Please
respond via email to: david@meduna.cs.missouri.edu
Regards,
David
------------------------------
Date: 19 Sep 92 09:07:08 GMT
From: Spacelink <spacelink@kiwi.gen.nz>
Subject: New Information Source
Newsgroups: sci.space,sci.space.shuttle,sci.astro
Spacelink is a Space Information Bureau based in New Zealand. Our aim is
to supply answers to people's questions whether they be simple or complex
on the history of human accomplishments in space.
You can contact us though our Email address of spacelink@crfm.gen.nz,
by writing to Spacelink at PO Box 331402, Takapuna, Auckland 9, New Zealand,
(Please enclose an SASE), or by Fax on 64-9-849-4282.
This is a free service for the curious, supplied by a team of voluntary
spaceflight enthusiasts.
--
DOMAIN: spacelink@crfm.gen.nz
SNAIL: PO Box 331402, Takapuna, Auckland 9, New Zealand
FAX: 64-9-849-4282
REPLIES: spacelink@crfm.gen.nz until further notice (kiwi.gen.nz
------------------------------
Date: 19 Sep 92 20:49:09 GMT
From: Dave Tholen <tholen@galileo.ifa.hawaii.edu>
Subject: Pluto Direct Propulsion Options
Newsgroups: sci.space,sci.astro,alt.sci.planetary
David Knapp writes:
> What is your criteria for 'isothermal'? Wouldn't we expect *some* temperature
> differentials from solar heating even though albedos may not be extremely
> low?
The criterion was given right in the earlier message: "...which could be the
case is methane frost is everywhere." It all depends on the material. For
example, consider a swimming pool, half of which is in sunlight, and half of
which is in the shade of a house or tree. Walking around the concrete deck,
you may notice that the temperature of the concrete is different whether it
is in the sunlight or in the shade, but the temperature of the water will be
much more isothermal. It's all a question of energy transport, the thermal
inertias of the materials involved, and so on.
------------------------------
Date: 18 Sep 92 18:52:37 GMT
From: Richard Treitel <treitel@gracie.IntelliCorp.COM>
Subject: Property rights (was Terraforming needs to begin now)
Newsgroups: sci.space
This thread relates to law/ethics rather than science and to earth rather
than space. Could you two please move it to an appropriate newsgroup?
Thanks
- Richard
------------------------------
Date: 19 Sep 92 18:00:00 GMT
From: wingo%cspara.decnet@Fedex.Msfc.Nasa.Gov
Subject: Shuttle Replacement (was: One Small Step...)
Newsgroups: talk.politics.space,sci.space
In article <BurEv7.77E@zoo.toronto.edu>, henry@zoo.toronto.edu (Henry Spencer) writes...
>In article <17SEP199216441940@judy.uh.edu> wingo%cspara.decnet@Fedex.Msfc.Nasa.Gov writes:
>>[747] It is interesting that each time a new
>>upgrade has been added, the FAA required a new certification program as if
>>the upgrage was a new plane.
>
>Actually, if memory serves, the upgrades do get a somewhat streamlined
>version of certification. They've still got to demonstrate overall
>performance characteristics and the like, particularly where the upgrade
>has affected important characteristics like how hard the brakes have to
>work to stop the thing, but the airworthiness of the basic design does
>not have to be re-established all over again.
>
>>Also the follow on for the 747 is in the works. It is called the 777...
>
>Nope, sorry, you heard wrong. The 777 is indeed in the works, but it is
>*not* a 747 replacement. Boeing has no plans to stop building the 747
>any time in the foreseeable future. The 777 is substantially smaller
>(although it's a large airliner by anyone *else's* standards).
>--
Gotcha Henry. Notice that I did not say "replacement". I said "follow on".
You are right, 777 is not a replacement for the 747 BUT there are many of the
buyers of 747 that are switching their orders to the 777 platform. My source
for this is the internal Boeing newsletter. 777 is a replacement for the 747
in many markets especially the long range market. I won't bet the farm on that
last sentence however. Boeing already has many billions of dollars worth of
orders for the plane and it will not be in the air for another two years! Too
bad we can't do the space market that way.
Dennis, University of Alabama in Huntsville, (Home of 1/2 of the astronaut no
sex in space corps)
------------------------------
Date: 19 Sep 92 02:04:09 GMT
From: yannb@yang.earlham.edu
Subject: Solar radiation and astronauts
Newsgroups: sci.space
I read in a newspaper recently on how solar radiation would
affect astronauts on long space travels. The article mentioned a
scientist who discovered that solar radiation speeds up the aging process
to the brain, and that a mission to Mars should not take place until the
problem is solved.
I found that to be interesting, and I would like to know if
anyone out there could tell me nore about this.
Thanks!
/\
yannb@yang.earlham.edu |/ \
------
| |
Yann Bandy | /\ |
808 Abington Pike | || |
Earlham College /| \/ |\
Richmond, IN | / | | \ |
47374 |/ | | \|
| / | | \ |
|/ | | \|
/ | | \
|/ | | \|
MiGs |-------| |-------|
| |
are | /\ |
/| || |\
MASTERS!! |/ | || | \|
/ _| || |_ \
|/ =||= \|
\/
------------------------------
Date: 19 Sep 92 22:35:04 GMT
From: Henry Spencer <henry@zoo.toronto.edu>
Subject: Solar radiation and astronauts
Newsgroups: sci.space
In article <1992Sep18.210409.19548@yang.earlham.edu> yannb@yang.earlham.edu writes:
> I read in a newspaper recently on how solar radiation would
>affect astronauts on long space travels...
Actually, *solar* radiation is fairly insignificant except during a solar
flare. It's *galactic* radiation, specifically cosmic rays, that is a
major concern. Once you go beyond Earth's magnetosphere, which screens
out most charged-particle radiation, you have to worry about this.
Solar flares are intense enough to be lethal fairly quickly, but their
particles are not that energetic and you can screen them out without
too much trouble. Something like 10cm of water ("or what water turns
into once you run it through a human" --Zubrin) suffices here, so an
interplanetary ship will probably include a shielded "storm shelter"
area, big enough to hold all the astronauts for a day or two during
a serious flare. The one faint concern here is that we don't really
know the upper limit for solar flares, since big flares are uncommon
and we haven't been observing with good instruments for very long.
We've only seen a handful of really giant flares in the circa 40 years
of good observations, and records of things like radio propagation
suggest that some of the flares in the 1940s were bigger than anything
we have good data on.
Cosmic rays are more problematic, because they are so damned energetic.
A modest amount of shielding makes things worse, not better, because
when the shielding stops a cosmic ray, a shower of secondary radiation
results. To stop everything, you need maybe ten tons of shield per
square meter of surface... and shielding even a small storm shelter
to that extent is impractical on a near-future ship. For *most* cosmic
rays, it's better to have no shielding at all, since they tend to just
zip on straight through... but unfortunately, a small fraction of
cosmic rays are heavy nuclei, and they don't. You may recall that the
Apollo astronauts reported seeing small flashes of light with their
eyes closed; those flashes aren't fully understood, but the majority
opinion is that they were heavy cosmic rays destroying cells in the
astronauts' retinas. Presumably other nerve cells are also getting
zapped, less conspicuously.
The bottom line, as I understand it, is that if you use a storm shelter
against flares (if you don't, and there's a big flare, you die) but
don't have 10T/m^2 of cosmic-ray shielding, you're looking at about
one REM per week. This is okay for a few weeks, worrisome for a year
or two, and probably unacceptable for longer periods. Until we can
build ships big enough to be shielded without serious penalty (shield
mass grows with surface area, ship mass with volume, so a big enough
ship takes only a small mass penalty for shielding), we want to hold
flight time in open space to a minimum, and dig in at the destination.
>scientist who discovered that solar radiation speeds up the aging process
>to the brain...
Actually, accelerated aging is one of the two big effects of most any
kind of modest radiation dose. The other is increased probability
of cancer. If memory serves, NASA's crew radiation criteria boil down
to X% increase in cancer chances (I forget what X is) plus two years
general reduction in life expectancy.
--
There is nothing wrong with making | Henry Spencer @ U of Toronto Zoology
mistakes, but... make *new* ones. -D.Sim| henry@zoo.toronto.edu utzoo!henry
------------------------------
Date: 19 Sep 92 05:51:31 GMT
From: Frank Crary <fcrary@ucsu.Colorado.EDU>
Subject: Space Platforms (political, not physical : -)
Newsgroups: sci.space,talk.politics.space,alt.politics.marrou,alt.politics.libertarian
In article <STEINLY.92Sep17143018@topaz.ucsc.edu> steinly@topaz.ucsc.edu (Steinn Sigurdsson) writes:
> I doubt it: The Libertarians generally make clear exceptions, for
> occasions where one person harms another.
>
>??? My understanding on the radio was that if you wanted to pay the
>money to outpower someone on a frequency they either had to ante up
>or buy you out. So why couldn't the cubans turn on their counter to
>Radio Matri (sp?) - which under current rules the US has indicated
>they'd bomb if turned on...
>
>as to the satellite slots, if the treaty is abrogated and no slot
>assignments are allocated, why not just muscle out your favourite
>slot?
Because it would interfere with another's rights: The Libertarian's
position is that the _only_ valid role of government is keep one
person from abridging another's rights (specifically by punishment
after the fact, not by legal restrictions before the fact.) Personally,
this is slightly too extreme (even for me), so I won't try to defend it
further...
Frank Crary
CU Boulder
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End of Space Digest Volume 15 : Issue 224
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