Date: Tue, 25 May 93 05:19:56 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #624 To: Space Digest Readers Precedence: bulk Space Digest Tue, 25 May 93 Volume 16 : Issue 624 Today's Topics: Boeing TSTO concept (sort-of long) Carl Sagan, respected astronomer Dark sky property rights Detecting planets in other system (2 msgs) Hey Sherz! (For real!) Cost of LEO Interesting DC-X paper I cama accross. (2 msgs) Killing ET's LE-7 CAPTIVE FIRING TEST Looking for rocketry software... Moon Base Moon vs. asteroids, Mars, comets New DC-X GIF Pros and cons of the Moon Soyuz and Shuttle Comparisons Welcome to the Space Digest!! Please send your messages to "space@isu.isunet.edu", and (un)subscription requests of the form "Subscribe Space " to one of these addresses: listserv@uga (BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle (THENET), or space-REQUEST@isu.isunet.edu (Internet). ---------------------------------------------------------------------- Date: Tue, 25 May 1993 01:28:16 GMT From: Mary Shafer Subject: Boeing TSTO concept (sort-of long) Newsgroups: sci.space On Sun, 23 May 1993 14:47:41 GMT, gary@ke4zv.uucp (Gary Coffman) said: Gary> Even the simple aluminum honeycomb Gary> structures used on B-58 and B-70 should be adequate to the task. Gary> If you want overkill, substitute titanium for aluminum in the Gary> leading edges. The XB-70 was made of stainless steel honeycomb and it was anything but simple. (I think that it also had some titanium, but am not certain. The first time I saw the plane after it left Edwards, it was parked outside at the Air Force museum at Wright-Patterson. It was weeping rust from all the joints, even though it had just been freshly painted. They've got it indoors _now_ but I suspect it's too late.) ------------------------------ Date: Mon, 24 May 93 22:01:31 EDT From: Tom <18084TM@msu.edu> Subject: Carl Sagan, respected astronomer Olaf Vancura sez; >>...Carl Sagan is a well respected astronomer >>who teaches at Cornell. Frank Crary responds; >Have you ever read any of his professional papers? The one I look up >last month, for example, was truely pathetic (Wallace and Sagen's >1979 paper on the stability of water on Mars, under an insulating >layer of ice.) While it was an interesting idea, their model was >completely and obviously bogus (unless you think it's safe to assume >five meters of ice is totally transparent, among other things...) >A later paper, that reworked the model in a vaguely realistic >manner got a very different result. Well, well-respected in some circles. BTW, he isn't an astronomer. He's an astro-biologist. At least, that's what his degree is in. It's quite an accomplishment to get a degree in something whose subject matter doesn't actually exist. Well, carbon compounds... The story I heard is that after his defense, the astronomers were shaking their heads, muttering "Well, at least he knows biology" and the biologists were shaking their heads, saying "Well, at least he knows astronomy". :-) Any respect Sagan has in professional circles, from what I gather, is due to his influence on students and the public at large, in creating interest and support for astronomy and science in general. -Tommy Mac ------------------------------------------------------------------------- Tom McWilliams 517-355-2178 wk \ They communicated with the communists, 18084tm@ibm.cl.msu.edu 336-9591 hm \ and pacified the pacifists. -TimBuk3 ------------------------------------------------------------------------- ------------------------------ Date: Mon, 24 May 93 15:55:05 PDT From: Charlie Prael Subject: Dark sky property rights Newsgroups: sci.astro,sci.space,sci.econ jhart@agora.rain.com (Jim Hart) writes: > Nope. "Freedom of the Skies" treaties state that national soveriegnty > stops at the edge of the atmosphere. No nation has jurisdiction over > this case, so it must be settled by private arbitrators, much the Actually, that doesn't mean anything of the sort. A more realistic option is a multi-national arbitration commission, sponsored under the UN. You repeatedly expect the government to take a back seat on this. They won't. > same way the radio spectrum was divided up before the FCC stepped Ummm, are you aware of *who* divided up the radio spectrum? It was a subgroup of the League of Nations -- predecessor of the UN. There aren't any private representatives there -- it's all governmental appointees, representing governments. > in and usurped it, and much the way Internet and Usenet flourish > internationally with no FCC regulations. My suggestion is that the Really? Stop and take a look at (a) who sponsored these nets in the first place (Can you say ARPA?), and (b) how much regulations the networks undergo in their creation and maintenance, both within this country and in other countries. > arbitrators create a fungible, tradable property, a win-win solution, Maybe, but we're back to the question of who gets 'em. It's only a "win" solution for the people who are enfranchised to dark sky rights. Using your criteria, that is a narrow group of astronomers. That's like making the only people who are qualified to make chemical waste policy the people who make and use those chemicals. What about the rest of us, who don't buy or sell those chemicals, but are effected by them nonetheless? > instead of a win-lose absolutist solution of judging completely in favor > of one side or the other. > > As for "disenfranchising" casual stargazers, they were never enfranchised See the above argument. You're arguing that a narrow criteria is the only one possible for input. That doesn't really work very well, now does it? > in the first place; they have not invested in ground-based astronomy. > Practically, there is no way except money for dark sky users to > measurably demonstrate their level of commitment. If they want a piece > of the action they can go down to the local telescope shop, buy a nice > beginner's kit, and swap their receipts for megacandle certificates. I'm Actually, by that logic, I can claim a "piece of the action" by going into my opthamologists, and paying for a pair of contacts, or glasses. I've invested money in the ability to see things in the sky at night. Or, if it is my chosen hobby to go lie out on a sailboat, looking at the stars, I can claim that sailboat (or a portion thereof) as a legitimate investment in ground-based (or water-based, here) astronomy. Where does it stop? > not claiming this is 100% fair, but the property rights have to be defined > somehow. No totally fair solution is possible, but distributing the > property among astronomers by their proportion of investment in ground-based > astronomy is reasonably fair, eg it is far fairer than deciding absolutely > and inflexibly in favor of one side or the other. > > If a U.S. court refuses to recognize those property rights, eg by deciding > to ban adsats that have properly purchased megacandles, they will have to You've also got the problem of deciding who's got the right to issue megacandle certificates. Are they an international organization? A national one? A corporation? One operating under which national laws, with what international authorization. Are megacandle certs transferable from country to country, or are they valid only within the country of origin? What happens if a satellite with it's lights on shines into a country it doesn't have legitimate certification for? > enforce the ban by violating the international treaties and shooting down > the adsat when Russia or Europe, China, Japan, Brazil, Kazakhistan, India, > Israel, Pakistan, etc. launches it. The chances of this are small > enough insurance will cover it. I also hope my country is not so > stupid and hypocritical as to promote free enterprise and then > violate both property rights and international treaty is such > a violent and polluting manner. > > Jim Hart > jhart@agora.rain.com Jim, overall, this is *really* poorly thought out. As you can see from the above, there are just a *few* loopholes. Give me time, and a few lawyers, and I can shoot LOTS of holes in it. See the problem? ------------------------------------------------------------------ Charlie Prael - dante@shakala.com Shakala BBS (ClanZen Radio Network) Sunnyvale, CA +1-408-734-2289 ------------------------------ Date: 24 May 93 16:57:36 GMT From: clements@vax.ox.AC.UK Subject: Detecting planets in other system Newsgroups: sci.space In article <1993May24.033135.998@ucsu.Colorado.EDU>, fcrary@ucsu.Colorado.EDU (Frank Crary) writes: > In article <1993May21.143420.14225@vax.oxford.ac.uk> clements@vax.oxford.ac.uk writes: >>For Earthlike planets you'll need something along the lines of a 16m telescope >>of the moon. Someone mentioned the chance of using an astrometric telescope to do this, and that is perfectly correct. In this case you use the movements of the partent star to trace the mass distribution in the system, similar to the 'wobble' approach used to look for extrasolar planets from the earth. > > Actually, an interferometer(sp?) array in the thermal IR has a reasonable > chance, if you can get a couple of orbital telescopes and a baseline > of ~500,000 km. In the thermal IR the signal to noise (i.e. star's > flux to that of the planet) is greatest, since you are in the peak of > the planet's Plank curve but well away from the star's peak. > Use of thermal IR is certainly a good idea. The use of an interferometer pair/trio with one element in orbit, or more, is a bit tougher though. To do interferometry you need to fix the position of the antennae (or measure it) to consierably less than the wavelength of the radiation you're observing. This may be possible (though hard) in the radio, at metre wavelengths, where QUASAT and Radioastron have been proposed. Scaling that technology up by 5 orders of magnitude to 10 microns isn't going to be easy!!! If you want to do interferometry in the optical/IR, the ground or the moon is the best place for it as you then have a nicely solid base to stop things moving. Optical interferometers, like COAST, are in fact currently underway. However, if they are like radio interferometers, they are likely to have a pretty poor dynamic range, which is the one thing you need when looking for planets. So filled aperture methods are likely to remain the best bet... > Frank Crary > CU Boulder -- ================================================================================ Dave Clements, Oxford University Astrophysics Department ================================================================================ clements @ uk.ac.ox.vax | Umberto Eco is the *real* Comte de dlc @ uk.ac.ox.astro | Saint Germain... ================================================================================ ------------------------------ Date: Tue, 25 May 93 02:54:57 BST From: Ata Etemadi Subject: Detecting planets in other system Newsgroups: sci.space Anyone considered using Kilometric radiation ? I know we're being bathed in it but it shouldn't be too difficult to filter out the near-Earth stuff using two sensors (since its coming from close by). Planets with magnetic fields would likely be emitting coherent radiation at these wavelengths making the job a little easier. What you need is an underwater detector to filter out some of the noise, since Kilometric radiation penetrates water a long way down. This would be a darn good use for all those nuclear submarines out there. BTW I think the military use this wavelength of radiation for communicating with their subs. best regards Ata <(|)>. ------------------------------ From: Pat Subject: Hey Sherz! (For real!) Cost of LEO Newsgroups: sci.space Date: 24 May 1993 18:52:25 -0400 Organization: Express Access Online Communications, Greenbelt, MD USA Lines: 26 Message-Id: <1trjj9$md1@access.digex.net> References: <1tn3f7$e4o@hsc.usc.edu> <1tpt1o$mq4@hsc.usc.edu> <1993May24.190850.18571@iti.org> Nntp-Posting-Host: access.digex.net Sender: news@CRABAPPLE.SRV.CS.CMU.EDU Source-Info: Sender is really isu@VACATION.VENARI.CS.CMU.EDU Mass Return. Ken seems fixated on this measure of performance. I would suggest that we not look at mass returned, but Useful Cargo Returned. In that Case we have, 1 LDEF, 4-5 SpaceLab flights, and probably appx 100 GAS Cans. I am assuming that ASTRO could have flown as Expendables on a extended science mission and abandoned in orbit as opposed to abandoned in warehouse like it is now. Not a lot for 12 years of missions. The soviets probably have returned as much using capsula vehicles and with soyuz. pat Read this weeks space news for an editorial written by a russian, scathing BURAN and how much money it wasted. Great quote "DOn't make it better, make it like the American's" ------------------------------ Date: 24 May 1993 18:58:12 -0400 From: Pat Subject: Interesting DC-X paper I cama accross. Newsgroups: sci.space How about also? We are going ahead with plans to build a couple more prototypes.... or WE got enough data to Justify the DC-X' (DC-XA) and we will enhance the test program from there. pat who really thinks a test program needs more then just one X vehicle. THe X-1 had 3??? the 15 had 3, and i don't know about the others. ------------------------------ Date: 24 May 1993 19:00:06 -0400 From: Pat Subject: Interesting DC-X paper I cama accross. Newsgroups: sci.space So what's the Serial number of the DC-X? Maybe they should give it 6062, cuz that was the number for yeagers bird. pat ------------------------------ Date: Mon, 24 May 93 21:43:30 EDT From: Tom <18084TM@msu.edu> Subject: Killing ET's [Is killing an ET legal?] Pat sez; >>I think the Endangered Species act may apply. Also interfering with >>Diplomatic relations, and violsating the nuetrality act. Gary responds; >... >A diplomat has no status until his credentials are accepted by the >authorities of the country to which he is posted. >... Um, this brings up an important question. What if it's illegal to kill an ET, according to his (it's) laws, and their authorities are powerful enough to make us respect them, regardless or whether we 'recognize' their credentials? :-) -Tommy Mac ------------------------------------------------------------------------- Tom McWilliams 517-355-2178 wk \ They communicated with the communists, 18084tm@ibm.cl.msu.edu 336-9591 hm \ and pacified the pacifists. -TimBuk3 ------------------------------------------------------------------------- ------------------------------ Date: Tue, 25 May 1993 00:22:47 GMT From: Kazuo Yoshida NASDA/TKSC Subject: LE-7 CAPTIVE FIRING TEST Newsgroups: sci.space PRESS RELEASE LE-7 CAPTIVE FIRING TEST May 14, 1993 NASDA HQ, Tokyo National Space Development Agency of Japan (NASDA) will conduct the second series of the captive firing test of LE-7 engine for H-II launch vehicle at the Yoshinobu (H-II) Launch Complex, Osaki Range, Tanegashima Space Center (Address: Minamitane-machi, Kumage-gun, Kagoshima 891-37). The purposes of the tests are to verify the level of integrated performance of the first-stage propulsion system and to confirm the interface between the first- stage propulsion system and the ground support facilities at the launch complex. Schedule: DATE Firing Duration --------------- --------------------- May 20, 1993 20 seconds May 31, 1993 100 seconds June 15, 1993 full duration June 29, 1993 (depend on June 15) Each ignition time is scheduled at around 2:00 PM. The date and time are subject to change due to the weather condition and/or unexpected reasons. If you are interested in covering the each firing test, please contact below. **************************************************** For further information, please contact the following: Yoko Inomata, Akiko Suzuki/NASDA Public Relations Office, Tokyo Phone: 03-5470-4283, Fax: 03-5470-4130, asuzuki@rd.tksc.nasda.go.jp ------------------------------ Date: Mon, 24 May 1993 20:57:31 GMT From: mark pitcher 9208 U Subject: Looking for rocketry software... Newsgroups: sci.space A few years ago, I put together a simple program to help me determine what characteristics to expect from amateur rockets. By entering details about burn rates, nozzle configurations, etc., I was able to determine (usually within about 10%) the probable flight characteristics of the amateur rockets. I tested this program with data from sounding rockets (Nike Apache, Judi-Dart, Metroc, HAD, Emma, and a few others) and got about 5% error. A few weeks ago, I found some more specific literature, regained interest in the computer program, and put together a "Microsoft Windows" application that not only gives the flight characteristics, but draws graphs of the flight and gives "ideal" dimensions for casing sizes, nozzle shapes, etc. I have since found even more detailed information on rocket flight characteristics, and am putting together an even more elaborate program. With the information I have now, I _should_ be able to calculate not only the basic characteristics, but figure out how to orbit a payload on the rocket (which is the ultimate goal of us all, isn't it?) I am looking for other such computer programs that I can use as a guide, or to compare my results with. If you know of such a program, please email me and tell me where I can find it. Thanks. -- --------------------------------------------------Wilfrid Laurier University mpitche5@mach1.wlu.ca (Mark A. Pitcher) ---------------------------------------------------------------------------- "Good...Bad... I'm the one with the gun..." ------------------------------ Date: 24 May 93 22:34:51 GMT From: Tom Zych Subject: Moon Base Newsgroups: sci.space In article <1993May23.161212.10346@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes: >I've been on the other side of this with Nick, but comets and Earth >crossing asteroids may offer much higher commercial rewards. And >open space offers commercial potential for communications, manufacturing, >and perhaps even power. What's Luna offer? Maybe He3, some light metals >and oxygen buried in yet another gravity well. Not very appealing. First of all, unlike comets & asteroids, the moon is not going anywhere. Any other body large enough to be worth exploiting would require enormous delta-v to decelerate into earth orbit. As for orbital facilities, yes, they will be very valuable. Where are you going to get the raw materials? Hauling them up from Earth would be much more expensive than getting them on the moon. Energy cost is less than 5% of launch from Earth, and a mass driver can be used there, obviating any use of reaction mass until capture. >... I suggest we forget the dead >Moon, and like the pioneers crossing the western deserts to reach >the California gold fields, head for the most promising targets >first and let the desert rats comb the rest at leisure. Lunar >bases don't make economic or scientific sense, and they aren't >*necessary* stepping stones to the more interesting targets. Necessary, no. Economical and conducive to expanded programs, yes. -- Tom Zych tbz1823@hertz.njit.edu ------------------------------ Date: Mon, 24 May 93 21:22:00 EDT From: Tom <18084TM@msu.edu> Subject: Moon vs. asteroids, Mars, comets Henry Spencer sez; >Commercial justification for a return to the Moon is slim, but for >anything else -- Mars, asteroids, etc. -- it's nil. Ooh, boy, I may be going out on a limb, taking issue with Henry... :-) But this seems a little premature. Near-earth asteroids are, energy-wise, quite easy to get to, comets and asteroids are almost completely unkown, WRT to materials, but we expect them to contain many valuable materials for industry, life-processes, and space-faring in general. I'm thinking of volatiles, methane, water, etc., and metals. It seems there would be a large commercial justification in finding out what they actually are made of, since if our expectations are correct, they would make valuable targets for further exploration and/or exploitation. We've flown by 2 comets, and 1 asteroid, soon to see another up close. But the only analysis has been spectral, if I remember correctly. No penetrators or sample returns that could tell us how valuable these things actually are. -Tommy Mac ------------------------------------------------------------------------- Tom McWilliams 517-355-2178 wk \ They communicated with the communists, 18084tm@ibm.cl.msu.edu 336-9591 hm \ and pacified the pacifists. -TimBuk3 ------------------------------------------------------------------------- ------------------------------ Date: 24 May 1993 23:55:10 GMT From: "Chris W. Johnson" Subject: New DC-X GIF Newsgroups: sci.space In article Andy Cohen, Cohen@ssdgwy.mdc.com writes: > A new DC-X photo will be available very shortly on > bongo.cc.utexas.edu....pub/Delta Clipper > > The photo is of DC-X on the static firing test platform.....DCXSnds.gif That photo has now been made available (thanks again Andy). Also available is a good picture from the rollout taken by a friend who was nice enough to have it developed on a Photo CD and mailed to me (so if anyone wants the 3000x2000 version, just let me know :-). Anyway, the new images are as follows: pub/delta-clipper/images: dcx-static-test-rig.gif dcx-rollout.gif dcx-rollout.jpg ...and they're located on bongo.cc.utexas.edu (128.83.186.13) as usual. BTW, if, during the last two weeks, there were any DC-related postings that should be archived, please send 'em along. I was out of town on business. ----Chris Chris W. Johnson Internet: chrisj@emx.cc.utexas.edu UUCP: {husc6|uunet}!cs.utexas.edu!ut-emx!chrisj ...wishing the Delta Clipper team success in the upcoming DC-X flight tests. ------------------------------ Date: Mon, 24 May 1993 23:02:06 GMT From: Josh Hopkins Subject: Pros and cons of the Moon Newsgroups: sci.space The following discussion is about whether space based civilization will be on the Moon or in free space. I want too point out that I'm not favoring one over the other - it's not an either/ or question. gary@ke4zv.uucp (Gary Coffman) writes: stuff with one > >Nick Janow writes: stuff with >> >>Gary Coffman writes: stuff with >>> >> >>The moon offers easily available metal and oxygen ores and a gravitational >>field, and is nearby (short communication times and within manned reach). It >>would probably be cheaper and easier to develop a resource extraction >>facility there than to develop zero-g facilities for extracting water from >>near-Earth asteroids. >Perhaps not. To mention only a couple of free space advantages, continous >solar power and relatively easy availability of any desired temperature. >The temperature extremes on the surface are much higher than on Earth >or in free space on a thermally controlled platform. It's nearly trivial >to keep any desired temperature by use of paints and rotation in space. It's not hard to control temperature on the Moon either. Passive shading allows temperatures as low as 40 K. The Moon also offers a massive heat sink. >The *lack* of a gravity well simplifies large structures and reduces the >energy requirements for materials handling. The structures issue is not obvious to me. 1/6 G does not cause enormous structural requirements. On the other hand, it does limit vibrations problems and gives a massive body for moments to act against. >There are some emergency scenarios where a three day transit time is >less of a problem than a 6 month transit time, but most situations >would require either immediate help or don't bother. On the other hand, day to day issues in industry do depend on interaction with multiple sources. If you need spare parts, on site experts or other imported products, it may be difficult to run a business where those choices have to be made a few months in advance (assuming the comparison is deep space activity, not cis-lunar). >>The technology and facilities developed with a lunar base project would >>greatly reduce the cost of developing open-space projects. It would be a >>more gradual development; technology in small steps, rather than one risky >>leap. >Are we sure of this? None of the material transport systems developed would be >useful in open space. Few of the radiation protection or thermal shielding >techniques would translate. Most of the processes would be totally different >because of the gravity well and differences in ores. For men on site, even >the spacesuit designs would be radically different. Even 1/6 G changes the >best manner of locomotion grossly. You can't really "walk" in space despite >the popular media's phrasing. I agree that the technology would be different. However, for all the examples you cite, working on the Moon is _easier_ than free space. >Luna would offer the additional complication of dust being >tracked into the habitat every time someone or something is moved through >a lock. I agree with this one. >>>Lunar bases don't make economic or >>> scientific sense, and they aren't *necessary* stepping stones to the more >>> interesting targets. >> >>They aren't *necessary*, but they could make economic and scientific sense. >The only real scientific mission of value to Luna would be a radio observatory >on the farside where the sensitive receivers could be shielded effectively >from the radio noise of Earth. Optical observatories are probably better >placed in open space because of the microscopic distortions introduced by >the Lunar gravity field, though there is something to be said for a large >inactive anchor point. That would be disturbed by lunar mining and blasting, >so the two are unlikely to coexist happily. There are benefits to be found on the Moon for all types of astronomy, from plain old ordinary optical stuff to gravity wave telescopes. Tiny gravitational distortions and human vibrations are far outweighed by what is otherwise a very stable surface. Lunar siesmic activity is about 100 millionth that present on Earth. This stability is available over a huge area with effort necessary by the hardware. This contrasts greatly with the troubles space based observatories have with vibration, short orbital periods and active pointing and stability. People are already proposing optical interferometers and gravity wave detectors spread out over kilometers. It's _very_ hard to do that in free space. The Moon also offers benefits in atmosphere (the density is lower than in LEO), and resources. Lunar bases and observatories can use everything from simple terrain or regolith to local materials like oxygen, glasses and cements. -- Josh Hopkins jbh55289@uxa.cso.uiuc.edu "This Universe never did make sense; I suspect it was built on government contract." -RAH ------------------------------ Date: Mon, 24 May 1993 22:49:02 GMT From: Dave Michelson Subject: Soyuz and Shuttle Comparisons Newsgroups: sci.space In article <26958@ksr.com> clj@ksr.com (Chris Jones) writes: > >>Note that the Soyuz-derived Zond *was* launched by a Proton (SL-12). This >>may be the source of the confusion. > >I thought it was the SL-13, but I don't have a reference here. Can anyone >support or correct the following: > >Proton 2 stage SL-9 D >Proton 3 stage SL-12 D1 >Proton 4 stage SL-13 D1e According to Clark (The Soviet Manned Space Program), Zond 4--8 were launched using the four stage SL-12 variant and Salyut/Mir were launched using the three stage SL-13 variant. The two-stage Proton (SL-9) flew four times (and failed once) in 1965-66. The four-stage Proton (SL-12) is the one that the Russians have been trying to sell to the West as a launcher for geostationary satellites. -- Dave Michelson -- davem@ee.ubc.ca -- University of British Columbia ------------------------------ End of Space Digest Volume 16 : Issue 624 ------------------------------