1 Aucbvax.5658
    2 fa.space
    3 utzoo!decvax!ucbvax!space
    4 Tue Dec 29 03:35:24 1981
    5 SPACE Digest V2 #73
    6 >From OTA@S1-A Tue Dec 29 03:19:25 1981
    7 
    8 SPACE Digest                                      Volume 2 : Issue 73
    9 
   10 Today's Topics:
   11 			     Cables to an SPS
   12 			     Cables to an SPS
   13 			 Otrag pulls out of Libya
   14 ----------------------------------------------------------------------
   15 
   16 Date: 29 December 1981 02:12-EST
   17 From: Robert Elton Maas <REM MIT-MC AT>
   18 Subject: Cables to an SPS
   19 To: p-btempl at CCA-UNIX
   20 cc: SPACE at MIT-MC
   21 
   22     Date: 26 Dec 1981 00:05:43-EST
   23     From: p-btempl at CCA-UNIX (Brad Templeton)
   24     It occurs to me that even aiming at a reception station just above the
   25     atmosphere for cable transmission down to earth would not stop the
   26     complainers - it might cause them to complain more.
   27     If the SPS is at geosync orbit, then a station a few hundred miles up is
   28     effectively on the earth for most of the rotation cycle, so there would
   29     be lots of earth beyond the path of the beam, and worst of all, not just
   30     one place (like the desert)  Instead a whole circle of danger is sweeped
   31     out if any leakage occurs.
   32 This doesn't make sense. If the station a few hundred miles up is in normal
   33 orbit or otherwise moving with respect to the Earth, there's no way to
   34 connect a cable between the station and a fixed point on the Earth, which
   35 was the original idea of mine. On the other hand, if the station is fixed
   36 with respect to the Earth, as I intended, the geometry is fixed, the beam
   37 from the synchronous-orbit SPS always is aimed at the same place on or
   38 off the Earth. It can be arranged for the low-relay-station to be a quarter
   39 revolution away from the SPS (with respect to center of earth) so that the
   40 beam from SPS to relay-station is essentially tangent to the Earth, missing
   41 it at all times.  My original idea was to run the cable all the way from
   42 the SPS to the Earth, but I think the relay-station idea is a viable
   43 alterntive which doesn't involve part of the beam passing the relay station
   44 and striking the Earth. Only the side lobes have a chance of striking
   45 the Earth, and with the relay station several hundred miles from the Earth
   46 the side lobes reaching the Earth can be made insignificant.
   47 
   48 ------------------------------
   49 
   50 Date: 29 December 1981 02:41-EST
   51 From: Robert Elton Maas <REM MIT-MC AT>
   52 Subject: Cables to an SPS
   53 To: p-btempl at CCA-UNIX
   54 cc: SPACE at MIT-MC
   55 
   56 I don't see anything wrong with inventing a cheap way to put bulk
   57 materials into space and then reserving the shuttle for humans and
   58 fragile cargo. Thus the linear accelerator could be useful even
   59 though it works only for bulk cargo, reducing the need to reserve
   60 the shuttle for such loads, leaving it more free for other stuff.
   61 If delicate cargo can be packaged correctly so it can withstand the
   62 jarring of the accelerator, and if it's not too delicate to
   63 withstand the average acceleration, then even delicate cargo can
   64 be sent by accelerator.
   65 
   66 Here's another idea I just thought of. How about a rotating catapult
   67 in a vacuum chamber. There's a door that opens for a moment just as
   68 the load is released from the catapult and then closes quickly so
   69 not much air gets into the chamber.  The reason for the chamber is
   70 so the catapult can spin up to speed without encountering much
   71 air friction.  The whole contraption could be installed on a high
   72 mountain top or flown up in a baloon, so the air outside the chamber
   73 has much less pressure than sea-level, and the air inside could be a factor
   74 of ten lower pressure. The combination of high initial speed (because
   75 of spinning-up the catapult in a near vacuum) and nearness to the
   76 top of the atmosphere (because of location) possibly means a good
   77 shape (low friction, low turbulence) and a thin ablative coating
   78 would enable tossing up to a 100-mile altitude where a spacecraft
   79 could catch the projectiles and toss them to higher orbit etc.
   80 There would be a high velocity difference between the projectile and
   81 the orbiting relay (catch&re-toss) station, but that's easy to
   82 handle, just have a long arm that catches the projectile while
   83 withdrawing at high RPM (like the way a baseball player catches
   84 a fly ball) and then just rotates around (at constant RPM) to another
   85 position where it lets go of the projectile. Thus the catch&re-throw
   86 catapult has to withstand only centrifugal force while actually
   87 handling the load, no tangential force.  The force while spinning up
   88 preparatory to catching the load and while spinning down afterward
   89 is small (the computer can plan the catch a quarter to half orbit ahead of
   90 catch-time, i.e. as soon as it's released from Earth, then make minor
   91 adjustments in the spin-up as the projectile is tracked on its way
   92 up from Earth, making the spin-up quite smoothe. Note that the
   93 axis of the catapult-spin, the distance of the catcher from the
   94 pivot point, and the RPM, can all be controlled, achieving a perfect
   95 catch, the projectile exactly striking the catcher and the velocities
   96 of the projectile&catcher being zero at the moment of catching).
   97 
   98 ------------------------------
   99 
  100 Date: 29 Dec 1981 00:14:15-PST
  101 From: decvax!duke!unc!smb at Berkeley
  102 In-real-life: Steven M. Bellovin
  103 To: decvax!duke!unc!space@Berkeley
  104 Subject: Otrag pulls out of Libya
  105 Cc: POURNE@MIT-MC
  106 
  107 Otrag, a West German company that has been developing rockets with
  108 potential military applications, has halted testing work in Libya.
  109 They began withdrawing personnel and abandoning their launching base
  110 about two months ago.  American intelligence sources indicated that the
  111 company was using its ostensibly peaceful rocket program to mask
  112 efforts to sell military technology, including short-range rockets, to
  113 Libya, Pakistan, Iraq, and other countries; the company has denied such
  114 reports.
  115 
  116 Sources claim that the pullout followed an internal battle, in which
  117 Lutz Kayser, an aerospace engineer who founded the company, was fired.
  118 Kayser is reported to have remained in Libya, and is still working on
  119 missle development.
  120 
  121 The company now says it will refrain from developing its own launch
  122 facilities, instead using launch sites operated by other countries or
  123 international groups.  "This will help eliminate the political problems
  124 of Otrag-owned sites," said Frank Wukasch, president of Otrag.
  125 
  126 	From a N.Y. Times News Service article
  127 
  128 ------------------------------
  129 
  130 End of SPACE Digest
  131 *******************
  132 
  133 -----------------------------------------------------------------
  134  gopher://quux.org/ conversion by John Goerzen <jgoerzen@complete.org>
  135  of http://communication.ucsd.edu/A-News/
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  137 
  138 This Usenet Oldnews Archive
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  145 The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996 
  146  Bruce Jones, Henry Spencer, David Wiseman.
  147 
  148