Aucbvax.4781 fa.space utzoo!decvax!ucbvax!space Thu Oct 29 04:46:57 1981 SPACE Digest V2 #21 >From OTA@S1-A Thu Oct 29 03:55:23 1981 SPACE Digest Volume 2 : Issue 21 Today's Topics: Re: IC's and the space program Re: SPACE Digest V2 #20 ERRATA ---------------------------------------------------------------------- Date: 28 Oct 1981 11:13:56-EST From: cjh at CCA-UNIX (Chip Hitchcock) To: space at mit-mc Subject: Re: IC's and the space program Certainly there was a greater need for miniaturization in our space program, since there was less time and money available to develop the grossly powerful boosters the Russians were using (it's something of a truism that in the "space race" the Russians went for brute power while we went for compactness). Consider that the first Russian satellite weighed something over 100 pounds while the first American satellites were in the 5-10 pound class but certainly did more than 5-10% as much work. ------------------------------ Date: 28 Oct 1981 1205-PST From: Terry C. Savage Subject: Re: SPACE Digest V2 #20 To: Space-Enthusiasts at MIT-MC cc: TCS at USC-ECL In-Reply-To: Your message of 28-Oct-81 0402-PST VLSI TECHNOLOGY HAS BEEN ENCOURAGED IN A GENERAL WAY BY THE SPACE PROGRAM, BUT THE LINKAGE IS NOT REALLY DIRECT. THE MAIN MOTIVATION FOR THE IMPROVEMENT IN SEMICONDUCTOR TECHNOLOGY HAS BEEN FOR EARTH BASED COMMERCIAL APPLICATIONS, SUCH AS LARGE, FAST COMPUTERS. SEMICONDUCTOR PROCESSING IS VERY CAPITAL INTENSIVE, AND THE SMALL VOLUME ENTAILED IN MOST SPACE APPLICATIONS IS INSUFFICIENT TO JUSTIFY THE CAPITAL EXPENSE. THE CURRENT PUSH FOR EXPANDING SEMICONDUCTOR CAPABILITIES COMES PRIMARILY FROM THE MILITARY'S VHSIC PROGRAM, WHICH WILL HAVE SPACE APPLICATIONS BUT IS NOT DRIVEN BY SPACE. ------------------------------ Date: 28 Oct 1981 2221-PST From: Ted Anderson Subject: ERRATA To: space at MIT-MC I was called to my attention (by only one person) that my figures for dropping rocks on the earth were in error. In particular they were high by a factor of 4.18 (the number of joules in a calorie). I forgot that a tonne of HE is a billion calories not a billion Joules. The calculation is straight forward: The potential well of the earth is about 11 km/s. Thus the kinetic energy is .5*11000^2 Joules/Kg = 6e7; a tonne is 1000 kg so we have, 6e10 J/Tonne; now divide by 4e9 J/Tonne for HE and we get: 15 Tonnes of energy per tonne of mass. Sorry to foul it up in the first place. ------------------------------ End of SPACE Digest ******************* ----------------------------------------------------------------- gopher://quux.org/ conversion by John Goerzen of http://communication.ucsd.edu/A-News/ This Usenet Oldnews Archive article may be copied and distributed freely, provided: 1. There is no money collected for the text(s) of the articles. 2. The following notice remains appended to each copy: The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996 Bruce Jones, Henry Spencer, David Wiseman.