Aucbvax.5670 fa.space utzoo!decvax!ucbvax!space Wed Dec 30 03:33:20 1981 SPACE Digest V2 #74 >From OTA@S1-A Wed Dec 30 03:16:25 1981 SPACE Digest Volume 2 : Issue 74 Today's Topics: sps skyhook Re: Cables to an SPS Re: Cables to an SPS Transporting energy with space technology Building skyhooks Cables to an SPS / Fuel etc. for shuttle from space ---------------------------------------------------------------------- Date: 29 Dec 1981 02:54:56-PST From: menlo70!sytek!zehntel!berry at Berkeley To: sytek!menlo70!ucbvax!space@Berkeley Subject: sps skyhook Why can't we build the sps into the top of a geosynchronous skyhook and not have to beam microwaves ANYWHERE?? Then what can they scream about? -berry kercheval ------------------------------ Date: 29 Dec 1981 20:56:39-EST From: p-btempl at CCA-UNIX (Brad Templeton) To: REM at MIT-MC Subject: Re: Cables to an SPS Cc: SPACE at MIT-MC In response to your message of Tue Dec 29 02:13:19 1981: Your comment is correct - I must have been in a Christmas mood when composing. ------------------------------ Date: 29 Dec 1981 21:07:57-EST From: p-btempl at CCA-UNIX (Brad Templeton) To: REM at MIT-MC Subject: Re: Cables to an SPS Cc: SPACE at MIT-MC In response to your message of Tue Dec 29 02:42:33 1981: The idea of a spinning catapult in a vacuum was mentionned to me by I fellow whose name I forget at an L-5 party at the Denvention (world SF convention in Denver) this year. I'll try and dig up the paper he gave me on it. As far as using the STS as the only transport for people, I suppose that is workable, but just how many people could we bring up in them? If each STS launch costs 30 megabucks, we are still talking about a large chunk of money per person. How many people could you launch if they were packed like sardines? Would the number of shuttles to be built be reduced once a cheap cargo method like a skyhook was in the works? It still all boils down to ME not getting into space. In another 60 years we will probably not be in shape even for the smoothest rides, if the current funding trends continue. ------------------------------ Date: 29 Dec 1981 21:17:22-EST From: p-btempl at CCA-UNIX (Brad Templeton) To: energy at mit-mc, space at mit-mc Subject: Transporting energy with space technology Although oil is not, in my opinion, the way to go, we still have to face up to the fact that large quantities of money are going to be spent on digging oil out of the ground in the next few decades. The Canadian government alone expects 300 GIGABUCKS will be spent in the next decade or so on matters such as the tar sands and arctic oil. This is a lot of money, enough to buy a whole passle of Shuttle flights or to put a solar power unit in orbit. Can we get some of it spent on space? People are looking anxiously for a way to get oil out of the north down to the consumers in Canada and the US. It's all in ice, so tankers can't reach it unless they are submarines, pipelines are hard to build, and are very vulnerable to very costly sabatoge by natives who don't want them. What can space technology do to ship the power. It can either be shipped as oil or in another form. Is it possible to build one of the catapults talked about in the Space Digest to send oil to a touchdown off the coast from some refinery? What about in other forms? If we can build such a plant there, could the oil be burned, and the power sent up to reflectors or collectors in orbit to be beamed back down to the surface again? This may all sound like it will perpetuate oil, but it puts lots of those nice petrodollars into space. Or am I dreaming? Brad Templeton (p-btempl@cca-unix or decvax!watmath!bstempleton@Berkeley) ------------------------------ Date: 29 Dec 1981 20:51:33-PST From: ihnss!karn at Berkeley Subject: Building skyhooks Has anyone actually thought about the strategy of building skyhooks? Would you start at ground level, without anything at the top to pull the line out from the earth, or would you start at geostationary altitude and go in both directions to keep it balanced? I'm not sure that a partially completed (unanchored) skyhook could be kept stable long enough to be completed. Phil ------------------------------ Date: 30 December 1981 03:29-EST From: Robert Elton Maas Subject: Cables to an SPS / Fuel etc. for shuttle from space To: p-btempl at CCA-UNIX cc: SPACE at MIT-MC It'll be trivial to send down the hydrogen and oxygen used for the main engines of the shuttle, once we find a source of hydrogen (in water or elsewhere) and have space industry and SPS running. It should be reasonable to send down solid rocket fuel. The large fuel tank is lightweight so we might make a bunch of them in space and dump them in a bundle over the ocean where they will gently float down to the surface (of the ocean). I'd sort of like to know where the money goes that we claim costs so much for each shuttle flight. I think it's mostly prorating on the original construction, so the more we use the shuttle (up to its usable lifetime) the less it costs per flight. If we can get fuel and construction materials cheap, maybe we can reduce the cost of building additional orbiters, and thus bring down the cost per launch? What if we had 100 orbiters, running up and down commute flights on a semi-daily basis (go up one day, come down the next, immediately prepare for launch the next day). We're a long way from that now, but maybe someday with passengers packed like sardines we can put about 3000 people in space (30 per orbiter, 100 orbiters in fleet) each two or three days. With SRBs and fuel tanks prepared ahead of time, so we just stick them on the shuttle and add the fuel and launch the contraption with a short countdown, couldn't we do that? Let's see, that would be half a million per year. I guess that's not enough with 4.5 billion wanting to go up there. (If we really did semi-mass-produce orbiters, would be the unit cost?) ------------------------------ 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.