Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from beak.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests) ID ; Sat, 11 Nov 89 01:24:22 -0500 (EST) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sat, 11 Nov 89 01:24:00 -0500 (EST) Subject: SPACE Digest V10 #233 SPACE Digest Volume 10 : Issue 233 Today's Topics: Re: Moon Colonies / Ant Tanks? Re: Provisional Launch Scheme ESA / ARIANSPACE Re: COBE Press Kit (long) Request for Soviet info Pegasus Solar power Re: Moon Colonies / Ant Tanks? Frequently asked SPACE questions Re: Atomic weapon/power demographics ---------------------------------------------------------------------- Date: 10 Nov 89 15:58:51 GMT From: cs.utexas.edu!varvel@tut.cis.ohio-state.edu (Donald A. Varvel) Subject: Re: Moon Colonies / Ant Tanks? The comparison of Sasketchewan to the moon has started me thinking. I lived 15 years in North Dakota. There are significant differences between the Northern Plains and the moon. As was pointed out, the cost of the infrastructure and its technological sophistication is quite different. (There are no polar bears in the plains outside of zoos, Dan.) And in North Dakota there's supposed to be a summer. Consider winter, though. During blizzards you don't go out. When it's -20 with a wind you don't go out unprotected, and I suspect the time needed to dress in long johns, union suit, wool shirt and trousers, insulated boots, chopper mits, and snorkel parka is similar to the time needed to put on a space suit. (The result has a similar appearance.) All of this is not needed for just getting into a vehicle and driving somewhere else, but that would probably be the case on the moon as well. Buildings are nearly airtight, which has led to problems with accumulation of radon and pollutants. Apartment complexes with large common areas, such as pool and exercise room, go a long ways toward dealing with cabin fever. Shopping malls are connected indoors by definition, and constitute very substantial enclosed spaces. In fact, much of downtown Winnipeg is connected by tunnels and overhead walkways. Somebody once asked Arthur C. Clarke, who lives in Sri Lanka, what it would be like to live in a space colony. He replied, ``You'll have to ask my friend Isaac Asimov. He lives in New York.'' Asimov was asked why he created something as unattractive as the totally enclosed lifestyle of the earth civilization in _The Caves of Steel_. He simply couldn't understand what was unattractive about it. He _liked_ the idea of living in steel caves. People will choose to live on the moon. I doubt that I will be one of them, but I have no doubt that there will be many others. -- Don Varvel (varvel@cs.utexas.edu) ------------------------------ Date: 10 Nov 89 16:41:01 GMT From: usc!cs.utexas.edu!uwm.edu!mailrus!jarvis.csri.toronto.edu!utgpu!utzoo!henry@apple.com (Henry Spencer) Subject: Re: Provisional Launch Scheme ESA / ARIANSPACE In article <8911091529.AA25913@ucbvax.Berkeley.EDU> ROB@autoctrl.rug.ac.be ("Rob A. Vingerhoeds / Ghent State University") writes: >V35 December 1989 Spot 2 (plus six sub-satellites) Ariane 40 >V36 January 1990 Superbird B/BS2X Ariane 44L I believe these two have now been interchanged. Spot and friends are in no hurry, while Arianespace is contractually committed to launch Superbird *this year*, and there have been enough minor delays to cause some concern about that. -- A bit of tolerance is worth a | Henry Spencer at U of Toronto Zoology megabyte of flaming. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 10 Nov 89 21:08:59 GMT From: frooz!cfa.HARVARD.EDU@husc6.harvard.edu (Steve Willner) Subject: Re: COBE Press Kit (long) From article <14885@bfmny0.UU.NET>, by tneff@bfmny0.UU.NET (Tom Neff): > Neither this press kit nor the AvWeek article satisfactorily explains > a basic question: Why does COBE need that sun synchronous orbit? > Why isn't an ordinary equatorial orbit good enough? The telescope must not be pointed at either the Sun or the Earth, ever. It also has to cover the whole sky at least once, preferably twice, in a year. This is incredibly easy in a Sun-synchronous orbit with the orbit plane at (nearly) 90 degrees to the Earth-Sun line: just look directly away from the Earth and at 90 degrees from the Sun at all times, and you automatically scan the whole sky in six months. You never have to move the solar cells at all; you can even use them as part of the Sun shade. This is exactly what IRAS did, and I thought COBE was using the same orbit. I don't see any way to do the same thing in a low-inclination orbit without an incredibly complex guidance system. (Think about the pointing constraints when between the Earth and Sun.) Also, eclipses last almost half of every orbit, which means you need almost double the solar cell area and big batteries. Finally, it turns out that the heat load into the cryogen tank is higher, so it's harder to get as long a lifetime. The one thing I wonder about is that the press release mentioned eclipses; I don't see why there should be any in the IRAS-type orbit. Maybe COBE is using a slightly different orbit (i.e. not exactly 90 degrees to Earth-Sun line) for some reason. I didn't see the information in the press release, although the launch time suggests they are not far from that orbit. ------------------------------------------------------------------------- Steve Willner Phone 617-495-7123 Bitnet: willner@cfa 60 Garden St. FTS: 830-7123 UUCP: willner@cfa Cambridge, MA 02138 USA Internet: willner@cfa.harvard.edu ------------------------------ Date: 9 Nov 89 22:16:00 GMT From: texbell!merch!cpe!hal6000!jack@rutgers.edu Subject: Request for Soviet info I'm doing some research on the Soviet space program and Soviet space policy in general, and I'm looking for some good, current sources of information. Apart from tons of AWST articles and other journals, I have yet to find good books on the current program and policies. So, I turn to the net and sci.space for help. Does anyone have any suggestions as far as specific books or other info sources about Soviet space policy? I'm looking for things like international cooperation, commercialization, military applications, etc.. Any personal views or insight into the Soviet program would be a great help as well. Does anybody have any good ideas? George Tahu ...!texbell!letni!hal6000!jack or ...!uunet!swbat!texbell!letni!hal6000!jack Thanks! ------------------------------ Date: 10 Nov 89 16:49:25 GMT From: cs.utexas.edu!uwm.edu!mailrus!jarvis.csri.toronto.edu!utgpu!utzoo!henry@tut.cis.ohio-state.edu (Henry Spencer) Subject: Pegasus In article <27460001@hpcvia.CV.HP.COM> kas@hpcvia.CV.HP.COM (ken_scofield) writes: > I've seen a few references in recent weeks to the Pegasus project, such as: > Unfortunately, I must have come in in the middle of this conversation, as > I have scarcely a clue what it is... Pegasus is a small, privately-funded, air-launched satellite launcher being developed by Orbital Sciences Corp. and Hercules. It's a three-stage solid- fueled rocket (Hercules being a big solid-rocket manufacturer) with a wing (built by Rutan) and fins on the first stage. Initially it will be launched from NASA's B-52, using much the same hardware used to launch the X-15, but eventually OSC/H will have their own carrier aircraft. OSC/H seems to have its act together, with one or two paying customers already (the first launch is for a DARPA experimental small comsat and a NASA gas-release experiment) and a lot more interested. Pegasus development took something like 2.5 years at a total cost of something like $50M. First launch was set for late summer but has slipped to December because of problems with the interface between Pegasus and B-52. > ... What is the advantage of air launch? Mostly, getting up above much of the atmosphere. There is a further small benefit from being launched at 500 mph or so. Side benefits include the ability to launch to any orbital inclination (just fly the aircraft to a suitable starting point first) and simplification of safety requirements (fly out over ocean, avoiding problems with nearby people). -- A bit of tolerance is worth a | Henry Spencer at U of Toronto Zoology megabyte of flaming. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 10 Nov 89 15:44:11 GMT From: sco!joed@uunet.uu.net (setenv WALRUS green) Subject: Solar power I'm hoping that this hasn't already been answered; apologies to those who have to see yet another article with Galileo in it... I have heard several people claim that there is indeed enough light out near Jupiter for it to be practical to use solar panels. Now, I'm curious: is it true? Or is it that the panels would just have to be too huge (I'm assuming that size of panels will make up for lack of ligt; please corerect me if I am wrong). What kind of power output can you expect at varying distances from the sun? Oh, as a side note, has anyone asked the various groups that opposed Galileo why they didn't speak up about any of the other probes or satellites that have used RTGs? Thanks in advance. Joe Di Lellio ------------------------------ Date: 10 Nov 89 23:12:39 GMT From: cs.utexas.edu!varvel@tut.cis.ohio-state.edu (Donald A. Varvel) Subject: Re: Moon Colonies / Ant Tanks? In article <14894@bfmny0.UU.NET> tneff@bfmny0.UU.NET (Tom Neff) writes: :In article <181@cypress.cs.utexas.edu> varvel@cs.utexas.edu (Donald A. Varvel) writes: :>Somebody once asked Arthur C. Clarke, who lives in Sri Lanka, what :>it would be like to live in a space colony. He replied, ``You'll :>have to ask my friend Isaac Asimov. He lives in New York.'' Asimov :>was asked why he created something as unattractive as the totally :>enclosed lifestyle of the earth civilization in _The Caves of Steel_. :>He simply couldn't understand what was unattractive about it. He :>_liked_ the idea of living in steel caves. : :This gets repeated ad nauseam. : :A city like New York may look like a steel cave to someone like Clarke, :but it assuredly is not. It's a breathing organic entity literally :filled with life and ecology. It's quite diverse and TOTALLY :uncontrolled. I don't mind if country folk amuse themselves with :erroneous preconceptions about what cities are like :-) but don't :try and apply it to this debate as fact. : Certainly I recognize the Clarke comment as humorous. It was hardly my whole argument. I thought it fit nicely into that paragraph. The Northern Plains in dead of winter can be magically beautiful, and I didn't mention that either. The bit about Asimov liking the idea of living in steel caves is from his autobiography. It is genuine. Asimov is from New York. It has nothing to do with the ``erroneous preconceptions'' of ``country folk''. It probably has little to do with New York. I mentioned it to establish that there are people who prefer to be indoors nearly all the time. There are people who spend winters on the Northern Plains, in towns and small cities, and spend no more than a few minutes at a time, for weeks on end, unenclosed. In general, these are far from violent or antisocial people. A lot of them play bingo. Thus, there is another group that chooses to spend nearly all time indoors for extended periods. Such people exist. While I only know about New York City what I read, I have lived much of my life on the Northern Plains. There _are_ people such as I describe above. There are also people who look forward to winter for such outdoor activities as skiing and running, and such semi-outdoor activities as fishing. The indoor types might adapt quite happily to a lunar colony. The skiers and runners probably wouldn't. Unless they put in a walleye lake, the fishermen probably wouldn't either. Why would anyone want to live on the moon? Who knows? Medical? Adventure? Feeling useful? Science? Big money bingo? Just don't assume nobody would want to spend months on end indoors. Turning the original argument around, if you're living in a basement anyway, and enjoying it, why not live in a basement on the moon? -- Don Varvel (varvel@cs.utexas.edu) ------------------------------ Date: Fri, 10 Nov 89 04:00:21 PST From: Eugene Miya Subject: Frequently asked SPACE questions This list does change. This is a list of frequently asked questions on SPACE (which goes back before 1980). It is in development. Good summaries will be accepted in place of the answers given here. The point of this is to circulate existing information, and avoid rehashing old answers. Better to build on top than start again. Nothing more depressing than rehashing old topics for the 100th time. References are provided because they give more complete information than any short generalization. Questions fall into three basic types: 1) Where do I find some information about space? Try you local public library first. You do know how to use a library, don't you? Can't tell these days. The net is not a good place to ask for general information. Ask individuals if you must. There are other sources, use them, too. The net is a place for open ended discussion. 2) I have an idea which would improve space flight? Hope you aren't surprised but 9,999 out of 10,000 have usually been thought of before. Again, contact a direct individual source for evaluation. NASA fields thousands of these each day. 3) Miscellanous queries. Sorry, have to take them case by case. Initially, this message will be automatically posted once per month and hopefully, we can cut it back to quarterly. In time questions and good answers will be added (and maybe removed, nah). 1) What happen to Saturn V plans? What about reviving the Saturn V as a heavy-lift launcher? Possible but very expensive -- tools, subcontractors, plans, facilities are gone or converted for the shuttle, and would need rebuilding, re-testing, or even total redesign. 2) Where can I learn about space computers: shuttle, programming, core memories? %J Communications of the ACM %V 27 %N 9 %D September 1984 %K Special issue on space [shuttle] computers Other various AIAA and IEEE publications. Computers in Spaceflight: The NASA Experience James E. Tomayko 1988? 3) SETI computation articles? %A D. K. Cullers %A Ivan R. Linscott %A Bernard M. Oliver %T Signal Processing in SETI %J Communications of the ACM %V 28 %N 11 %D November 1984 %P 1151-1163 %K CR Categories and Subject Descriptors: D.4.1 [Operating Systems]: Process Management - concurrency; I.5.4 [Pattern Recognition]: Applications - signal processing; J.2 [Phsyical Sciences and Engineering]: astronomy General Terms: Design Additional Key Words and Phrases: digital Fourier transforms, finite impulse-response filters, interstellar communications, Search for Extra-terrestrial Intelligence, signal detection, spectrum analysis ------------------------------ Date: 10 Nov 89 22:38:27 GMT From: jon@june.cs.washington.edu (Jon Jacky) Subject: Re: Atomic weapon/power demographics > Peter Scott (pjs@grouch.jpl.nasa.gov) writes: ...the number of lives saved > by the invention of atomic power must be much greater than the number of > lives taken by atomic weapons (and then he cites many beneficial things > like radioisotopic medical scans, radiation therapy, etc...) I work in radiation therapy, so I couldn't resist responding to this one. There are many beneficial medical (and other) applications of ionizing radiation, but these have almost nothing to do with, and owe almost nothing to, the research conducted to produce atomic weapons. Peter's use of the term "atomic" is much too loose. One can categorize applications of nuclear technology and ionizing radiation in three categories: 1.) Nuclear weapons 2.) Nuclear power reactors 3.) Everything else The first two depend on nuclear fission, mostly the third does not. Historically, the first two are more closely coupled because the first nuclear reactors were built to produce materials to build nuclear bombs. The third category is more independent of the other two, and in fact predates them by a long time. Ionizing radiation was discovered in the 1890's. There are two ways you can get it: from electrical machines (X-ray tubes, linear accelerators, cyclotrons...) and from radioactive materials, either naturally occuring ones like radium and uranium or those produced in a reactor, like plutonium. Diagnostic radiology and radiation therapy using X-ray tubes and radium got started in the 1890's and were fairly developed by the 1930's. The first higher energy accelerator, the cyclotron, was invented in the 1930's. Fission, which makes nuclear reactors and nuclear weapons possible, was not discovered until 1938. Most medical applications of ionizing radiation do not depend on fission. Diagnostic radiology and radiation therapy primarily use X-ray tubes or accelerators. Many medical isotopes are manufactured in accelerators. It is true, some medical isotopes are manufactured in nuclear reactors. During the 1950's and 1960's many radiation therapy machines used as radiation sources cobalt or cesium isotopes manufactured in reactors. However, these began to be superceded by linear accelerators in the 1960's. Linear accelerators provide many conveniences overe isotopic sources. Not the least of which is, the hazards are in general easier to control. When they are turned off, they are turned off. A bit of residual radioactivity remains but it is not a serious problem. On the other hand there have been several serious incidents involving several deaths, due to improper disposal of isotopic sources from cesium and cobalt machines. In general, the electric methods of generating ionizing radiation save you most of the problems of dealing with troublesomely large quantities of long half-life isotopes. In summary, nuclear weapons, nuclear power and other applications of ionizing radiation are largely independent and each must justify itself on its own terms. A very good history of these matters can be found in the excellent book by physicist/historian Spencer Weart, called NUCLEAR FEAR: A HISTORY OF IMAGES. - Jonathan Jacky Department of Radiation Oncology University of Washington Seattle, WA 98195 jon@gaffer.rad.washington.edu ------------------------------ End of SPACE Digest V10 #233 *******************