🚀 go-pugleaf

>From OTA@S1-A Wed Oct 21 04:00:26 1981

SPACE Digest                                      Volume 2 : Issue 17

Today's Topics:
			   Carbonless plastics
			  Peaceful Uses of Rocks
				  Cosmos
			    Radiation pressure
	   SPS vs. Fusion - A response to REM / counterresponse
			   Begg talk at Hahvahd
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Date: 20 Oct 1981 1124-PDT
Sender: BILLW at SRI-KL
Subject: Carbonless plastics
From:  William "Chops" Westfield <BillW@SRI-KL>
To: space at MC
Cc: billw
Message-ID: <[SRI-KL]20-Oct-81 11:24:02.BILLW>

Aren't the silicones all carbonless ? (basically polymerized sand,
I think...) Furthermore dont silicones offer all sorts of advantages
over most other plastics in harsh envirenments ? (Things like ability
to withstand high temperature extremes, lack of vloitile to boil off,
and so on ?)

Bill W

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Date: 20 Oct 1981 1409-PDT
From: Paul Dietz <DIETZ at USC-ECL>
Subject: Peaceful Uses of Rocks
To: space at MIT-MC
cc: ota at S1-A, jef at LBL-UNIX

There has been a discussion on ARMS-D about the military potential of
the SPS.  It was pointed out that if you can build an SPS you can also
drop large masses onto your enemy.  Dropped from infinity, 1 ton of
rock = 60 tons of TNT, so a 4 meter spherical asteroid yields 60 KT
(thanks to OTA for these figures).  

There have been proposals for using nuclear explosives for peaceful
purposes (digging canals and such).  These efforts were scuttled by
the test ban treaty.  Using asteroids we can get around the problem of
radioactive fallout, not to mention the savings in fissile material.

This illustrates that there is an additional energy source in space:
gravitational potential energy.  Is there an easy controlled way of
extracting this energy? 
-------

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Date: 20 Oct 1981 16:51:11-PDT
From: vax135!hocsb!dcs at Berkeley
FROM: d.c.smith
TO: vax135!ucbvax!space@Berkeley
DATE: 10/20/81, 12:38 PM
SUBJECT: Cosmos
Can anyone tell me if Carl Sagan's series "Cosmos" can be purchased on
videotape?

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Date: 20 October 1981 22:58-EDT
From: Gene Salamin <ES at MIT-MC>
Subject: Radiation pressure
To: SPACE at MIT-MC

     For a beam of light, the radiation pressure P (in Newtons/meter^2)
is given by U/c, where U is the intensity (in Watts/meter^2) and c =
3.0e8 meters/second is the speed of light.  Taking the intensity as
1 kW/m^2, the pressure is 3.3e-6 N/m^2.  This ignores the pressure of
solar wind.  The radiation beamed down by an SPS produces a recoil,
but since only 10% or so of the incident solar energy gets into the beam,
the recoil force is only 10% of the incident force.

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Date: 21 October 1981 03:53-EDT
From: Jerry E. Pournelle <POURNE at MIT-MC>
Subject: SPS vs. Fusion - A response to REM / counterresponse
To: REM at MIT-MC
cc: SPACE at MIT-MC, DIETZ at USC-ECL

MOONROCKS CAN BE SIMULATED TO ANY DEGREE OF SIMILARITY YOU WANT,
AND IN VERY LARGE QUANTITIES; PROCESSING HAS BEEN DONE ON
SIMULACRA

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Date: 21 October 1981 04:04-EDT
From: Jerry E. Pournelle <POURNE at MIT-MC>
Subject: Begg talk at Hahvahd
To: JNC at MIT-XX
cc: SPACE at MIT-MC, mph at MIT-XX, ludwig at MIT-XX, wayne at MIT-XX

I TTO AM and have been impressed with Beggs, and with his Deputy
Hans Mark.  When Beggs made his first public appearance as
Administrator at an AIAA convention, I overheard someone in the
audience say "Jeez, we got a philosopher for an
administrator..."

As to public acceptance of space, it's mostly that they are
finally becoming AWARE of public activities and public interest;
washington doesn't listen to the nation, but it does read its
mail.
	The L-5 campaigns have been very effective.  Note also
that in a few short years the idea of lunar mines in this
century hs become an acceptable goal.
	Please excuse the horrid typing.  I get NO feedback on
this loop in the net; the lines are very flakey, and will be for
a while until I can get a new 1200 baud system and operate on a
different TIP.
Thanks for puttin  up with the noise.

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End of SPACE Digest
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