Aucbvax.4408
fa.space
utzoo!decvax!ucbvax!space
Wed Oct 14 11:59:53 1981
SPACE Digest V2 #14
>From OTA@S1-A Wed Oct 14 11:41:22 1981
SPACE Digest Volume 2 : Issue 14
Today's Topics:
character
booze money
Drawbacks of SPS, hazards of fission use
Enigmatic letter from NASA and budget cuts
subduing Mother Nature
Bigotry in Space
booze money
space heat sinks
SPS Flamage
Budget cutting - yer message regarding same; an idea
SPS continued
SPS continued / solar-sail side-effect
SPS & Fusion
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Date: 13 Oct 1981 12:02:42-EDT
From: cjh at CCA-UNIX (Chip Hitchcock)
To: space at mit-mc
Subject: character
Cc: dlw at mit-ai
The faults you find in opponents of nuclear power are no more common
than similar faults in the active proponents of nuclear power---and the
proponents usually have more money with which to push their views.
------------------------------
Date: 13 Oct 1981 12:08:00-EDT
From: cjh at CCA-UNIX (Chip Hitchcock)
To: space at mit-ai
Subject: booze money
Cc: pourne at mit-mc
I am curious about any sources indicating that 5% of our GNP
($100 billion out of $2 trillion) is spent on booze.
Possibly you mean that that much could be raised over a large number
of years---but this is not at all clear from what you have said.
In fact, I have seen claims that taxes amount to up to 80% of the
retail price of liquor, and the last time I looked, BATF (the Bureau of
Alcohol, Tobacco, and Firearms) was not collecting any huge amount of
revenue (my memory oscillates between $7 and $15 billion for everything
put together).
------------------------------
Date: 13 Oct 1981 1315-EDT
From: Gene Hastings <HASTINGS AT CMU-20C>
Subject: Drawbacks of SPS, hazards of fission use
To: space at MIT-MC
Something which bothers me is the (apparent?) vulnerability
of SPS. Isn't it far too easy for an unfriendly power (political or
corporate) to knock it out? Would that mean that the stations would
have to be hardened and equipped with anti-missiles? Suppose that
such defenses are needed: what is the likelihood that they would be
scrubbed because of oversight, ignorance, or political necessity
(you are putting missiles on satellite? And you say it's ONLY for
defense? Hah! Imperialist pig! etc.).
A concern that I have not been able to answer is the not
uncommon fear that although fission may be capable of being run
safely, as long as there are ordinary people running it, it won't
be. Consider the apparent attitude of many utilities that a fission
plant is just another kind of boiler, and needs no more thought
than those used in the past. (Yes it can be argued that because
of ash and other hazards, not even the traditional boilers can
be run as thoughtlessly.) I don't have a great deal of faith in
the safety of such an operation unless everybody in it, from the
everyday joes at the bottom, through the middle managers who used
to be everyday joes, up to the movers and shakers are both educated
in what is necessary, and motivated to do it. I don't see where
either the education or motivation are coming from.
Gene Hastings
-------
------------------------------
From: BRUC@MIT-ML
Date: 10/13/81 13:44:38
Subject: Enigmatic letter from NASA and budget cuts
BRUC@MIT-ML 10/13/81 13:44:38 Re: Enigmatic letter from NASA and budget cuts
To: space-enthusiasts at MIT-MC
My wife and I sent a letter to President Reagan in support
of NASA back in March. We received a reply from James W. McCulla,
Chief, Public Services, Public Affairs Division, NASA dated October 1.
The letter read as follows:
Your letter to President Reagan has been referred to this office,
and we are please to respond accordingly.
Thanks for your combined effort supporting a strong, well-funded
space program.
Look for a decided move in the space funding picture during the
next several months.
They also enclosed a copy of Spinoff 81, a description of NASA spinoffs.
It must have cost them a few dollars to print and send that to me.
I presume the decided move is some new project ( Space
Operations Center perhaps). I can't imagine they'd send a letter like
that if the "decided move" is a 6% budget cut. The latest round of
budget cuts were proposed before Oct. 1. Does anyone know what's
\really/ going on?
Bob Bruccoleri
------------------------------
Date: 13 Oct 1981 1516-CDT
From: Jonathan Slocum <LRC.SLOCUM AT UTEXAS-20>
Subject: subduing Mother Nature
To: space at MIT-MC
Until we're ready and able to create fusion materials ex nihilo, we can
surely dispense with these useless arguments re: fusion vs. SPS from the
philosophical standpoint of "taking" vs. "accepting". I see no principled
difference between harvesting radiant energy and harvesting deuterium from
the oceans: in either case, we're stuck with whatever Mother Nature has
made available to us.
In any case, arguments such as these will not have the slightest effect
on whatever choice we (or anyone else) make. Barring any universally
recognized moral issues (on a level with wholesale human sacrifice), the
issue will be resolved on the usual engineering and cost-benefit basis,
with an unfortunate amount of pure politicking thrown in to boot. And I
really doubt we have enough data now to determine the better solution w.r.t.
making energy available here on earth. As to using it in space, the answer
is presumably more clear? (Of course, there is plenty of hydrogen available
in the atmospheres of the gas giants and some of their moons...)
-------
------------------------------
Date: 13 Oct 1981 1443-PDT
From: Paul Dietz <DIETZ AT USC-ECL>
Subject: Bigotry in Space
To: space at MIT-MC
What?! The japanese or the europeans or ...gasp.. all those people
who speak SWAHILI might build bright, shiny SPS's before we do?! What
a truly horrifying scenario! The next thing you know one of them will
marry your daughter.
-------
------------------------------
Date: 14 October 1981 03:42-EDT
From: Jerry E. Pournelle <POURNE MIT-MC AT>
Subject: booze money
To: cjh at CCA-UNIX
cc: POURNE at MIT-MC, space at MIT-AI
I have never said that 5% of GNP is spent on liquor. Why should
I? Snce SPS requires something like $80 billion for the first
one, and about $10 for each additional copy (assuming that it is
done from the ground and not done the Criswell way with lunar
base) then some $10 billion a year will do the job handily. I
am absolutely certain that more than that is spent annually on
liquor.
Nor do I advocate prohibition and confiscation of money that
might have been spent on liquor. If, however, the alternative is
cutting liquor consumption in half or letting civilization
collapse for want of pollution-free energy...
------------------------------
Date: 14 October 1981 03:51-EDT
From: Jerry E. Pournelle <POURNE MIT-MC AT>
Subject: space heat sinks
To: KING at RUTGERS
cc: SPACE at MIT-MC
thrown powders including
discussion of many technical problems can be found in the
proceeedings of the third conference on radiation in space,
published by the Ames research labs.
The conclusion was that this is one method of getting
rid of waste heat. There are said to be others.
------------------------------
Date: 14 October 1981 04:11-EDT
From: Jerry E. Pournelle <POURNE MIT-MC AT>
Subject: SPS Flamage
To: Tavares.Multics at MIT-MULTICS
cc: "TO:" at MIT-MC, SPACE-ENTHUSIASTS at MIT-MC
Sigh. Does NO ONE read anything before making up their minds?
The standard SPS design uses power received on Earth and sent
back up to the satellite as the source power for colimation of
the micro-wave beam. (The beam is about twice the energy
density of sunlight under the reference plan; certainly no more
than four to six times it under ANY plan.)
If the beam wanders, the power is no received; if not
received it cannot be retransmitted; if not retransmitted, the
colimator is unpowered; if no colimator, no beam, and the power
is simply dispersed.
Microwaves are not the only way to get pwoer to
Earth. And for that matter, power in space is worth having even
if none is ever sent to earth.
------------------------------
Date: 14 October 1981 04:30-EDT
From: Robert Elton Maas <REM MIT-MC AT>
Subject: Budget cutting - yer message regarding same; an idea
To: OAF at MIT-MC
cc: SPACE at MIT-MC, TAW at SU-AI
If the voters and Congress don't want to invest in space...
Rather than give up without a fight and all move to Japan...
Maybe we can tell Exxon and ITT and Xerox some of the wonderful things
possible in space, and how cheap the initial experiments can be,
and they can pressure Congress to PERMIT these companies to finance
the 4th and 5th shuttle-orbiter and then rent space to other (smaller)
companies to whom we also tell these revelations.
Congress will "benefit" because they can cut that part of the space
budget and spend it elsewhere (Halley, Galileo, LEO) to get us
all of their backs. Exxon et al will profit, if they also get
Congress to PERMIT these other companies to develop and implement
proprietary industrial processes using rented shuttle space.
I'm not sure this will work. Just a sketch of an idea to bounce
around and fill in the details.
------------------------------
Date: 14 October 1981 04:40-EDT
From: Robert Elton Maas <REM MIT-MC AT>
Subject: SPS continued
To: CSVAX.tuttle at UCB-C70
cc: SPACE at MIT-MC
I don't see how the volume of materials for an SPS is a capital
investment. Capital means MONEY, not dirt. If we build a cheap
device on the moon (say $1,000,000 for device and rocket to move
it from LEO to moon) that automatically under remote
control mines ton after ton of lunar dirt and throws it into space,
an after a few years there's enough of it in space to build
an SPS, where's the capital investment? Answer, except for
the cost of the original moon-mining device, and the personnel
salaries to remote-control it, there is no capital investment.
Nuclear fusion, on the other hand, requires investments of
billions of dollars. SPS just takes a teensy capital investment and
a few years to give it time to do the mining and fabricating.
------------------------------
Date: 14 October 1981 04:54-EDT
From: Robert Elton Maas <REM MIT-MC AT>
Subject: SPS continued / solar-sail side-effect
To: CSVAX.tuttle at UCB-C70
cc: SPACE at MIT-MC, minsky at MIT-AI, e.jeffc at UCB-C70
Your calculation of the change of momentum caused by solar sail
effect in SPS ignores the fact that half the time the SPS is going
toward the sun and half the time away so the net momentum over
time is zero. Of course it perturbs it slightly into a funny shaped
orbit and you have to compensate, but it certainly doesn't
build up momentum monotonically over time.
This effect can actually be used to benefit. Station the SPS over
the North or South pole, instead of in geosync orbit, and somewhat
"behind" the Earth with respect to the incoming light.
If the SPS collector can be angled so that the light that isn't
absorbed is mostly reflected down toward the dark side of the
Earth, the delta-Vee of the sunlight can be directed toward
the center of the Earth, an thus the reaction force pushing the
SPS will be directly upward from Earth, so it just levitates there,
doesn't have to orbit. This makes design of the SPS easier since
it doesn't have to dynamically rotate its collector with respect
to its microwave beam as the assembly moves around the Earth.
------------------------------
Date: 14 October 1981 05:32-EDT
From: Robert Elton Maas <REM MIT-MC AT>
Subject: SPS & Fusion
To: DIETZ at USC-ECL
cc: SPACE at MIT-MC, POURNE at MIT-MC, jpm at SU-AI
Let me take this opportunity to quibble strongly on your claim that
there are many ways to build a fusion reactor but only one way to
harness solar energy in space (build an SPS as you say), and that
somehow that means fusion is more cost-effective.
First, who cares? It only takes one way. If all the fusion methods
fail, and the one obvious SPS way works fine, then SPS is ahead of fusion.
The count of methods that "might" work but don't is irrelevant.
But actually you have it backwards.
There are only two ways to make fusion work on Earth:
1: You confine some fusable fuel (protons and/or deuterons and/or trits)
at high enough temperature and pressure for long enough time that
a bunch of the particles fuse and release energy you can collect.
(That's similar to the way the Sun, and tokamaks, do it.)
2: You introduce a shock wave in some material so that along the shock
front particles are thrown together and fuse. (That's similar to
the way stars form in spiral arms of galaxies and how gunpowder works.)
Can you think of any other way?
There are more ways to make an SPS:
1: You spread photo-voltaic cells across a large area and feed the
electricity into a collector grid.
2: You spread reflectors across a large area, concentrate the light
onto a small bunch of high-temperature photo-voltaic cells.
3: You reflect the light as in 2 but use it to boil some fluid and
drive a heat engine (steam turbine etc.).
4: You spread a lot of small reflectors and teensy boilers cross
a large area and feed the electricity into a collector grid.
5: You reflect the sunlight directly on some process, such as
high-temperature materials refining or weather modification,
instead of making electicity as an intermediary.
6: You use the momentum-transfer of sunlight to directly drive
some motion device (like solar sails, but mounted on a rotary
shaft as in those little toys that ran the wrong way when first
invented), and then use the motion to direcly run industrial
processes and/or drive a generator.
------------------------------
End of SPACE Digest
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