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 ---------------------------------------------------------------------- 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 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 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 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 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 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 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 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 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 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 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 ******************* ----------------------------------------------------------------- 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.