Date: Mon, 7 Jun 93 05:37:32 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #696 To: Space Digest Readers Precedence: bulk Space Digest Mon, 7 Jun 93 Volume 16 : Issue 696 Today's Topics: 1992 NASA Authorization Budget- shuttle Big Rock Can Hit Earth in Yr 2000 Billboards DC-X turnaround Early SF; How early? fresh lamb, anyone? How would we get back to the moon, if we had to? Loudmouths or policy-makers? manifest destiny = US getting uppity again (3 msgs) mass drivers (3 msgs) Moon Base SETI: viral mediums and Ukranian radio astronomy That Salsman Guy Why are SSTO up-front costs rising? 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: 6 Jun 93 17:50:27 From: Steinn Sigurdsson Subject: 1992 NASA Authorization Budget- shuttle Newsgroups: sci.space In article <1uu0gl$1vi@access.digex.net> prb@access.digex.net (Pat) writes: I don't know about Saab, and the swedish defense complex, but The soviets have maintained their aero-space bureaus, and their basic industries have collapsed. I don't see it helping them much. Necessary != sufficient. Many things can be destroyed, but it is harder to build them up, later. We could burn japan to the ground, would that help us? i am not real sure. The point is that comparative advantage spread to international markets is only rational if you're prepared to trust your competitors/partners in perpetuity, at least for critical industries. In practise that means Japan grows rice and Sweden builds fighters. | Steinn Sigurdsson |I saw two shooting stars last night | | Lick Observatory |I wished on them but they were only satellites | | steinly@lick.ucsc.edu |Is it wrong to wish on space hardware? | | "standard disclaimer" |I wish, I wish, I wish you'd care - B.B. 1983 | ------------------------------ Date: 7 Jun 93 06:47:05 GMT From: richard steven walz Subject: Big Rock Can Hit Earth in Yr 2000 Newsgroups: sci.space In article <12837@sun13.scri.fsu.edu> jac@ds8.scri.fsu.edu (Jim Carr) writes: >In article <1uh7ej$2k6@access.usask.ca> choy@dvinci (Henry Choy) writes: >> ... Is anyone >>thinking of >> - blowing it away? > >has to be careful that the pieces do not hit the earth when the >object itself would miss and only affect some tides here and there. > ------------------------ Absurd. The thing is reported to be a km or so! The tidal effect wouldn't be noticeable unless you're talking about chaos theory! Also it takes the same energy to reach it as to go without it, so it wouldn't give anything a free ride. I can envision a mission to find out what it's made of and then to determine whether to fragment it and see what's left or else to deflect it early enough if it is actually on collision path with us. If it's NiFe then forget fragmenting it and push it out of collision orbit. If its Carb/Chond. then maybe fragment it with big nuke. Then if anything is left, it will either miss or we can nuke the larger pieces again. -RSW ------------------------------ Date: Mon, 07 Jun 93 01:32:47 EDT From: Tom <18084TM@msu.edu> Subject: Billboards Iain Wacey sez; > The reason that Vermont does not have billboards is because they are >ugly... So much for objective, uderstandable law. There's a billboard on the Delta hangar at Detroit Metro, and it's just a giant painting of an airplane. What's really cool is that it's only visible as you get off the freeway, and come out from an underpass on the road laeding to the terminals. You look up, and here's this giant picture of an airplane. After you continue for a bit, you realize the picture only makes sense from the angle just past the underpass, since it's painted on two sides of the hangar, with the 90 degree corner facing you. Point being, that it's not ugly at all. It's an airplane, and a neat optical illusion, to boot. So why doesn't Vermont just prohibit the ugly billboards? They could save time and just prohibit ugly things, like, say, laws based on subjective opinions...point being that aesthetic arguments don't work for billboard prohibition. Aesthetics might be the driving force behind pressure-groups, but that's not an argument, is it? -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, 07 Jun 93 01:16:54 EDT From: Tom <18084TM@msu.edu> Subject: DC-X turnaround Andy Cohen sez; >>I heard that they require an 8 hour turn around before firing again..... Allen responds; >Yep! >>EIGHT hours. >Not bad huh? >>and I may be off by two hours too...it may have been 6... I just could not >>believe what I heard. >No, it was eight hours. Not only that, yesterday wasn't the first time >they did it... Wasn't it designed for (fundung based on) a 24-hour turnaround? Boy, I tell ya, the thing hasn't even flown, and they're already missing their design goals by a factor of three :-) -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, 07 Jun 93 01:07:16 EDT From: Tom <18084TM@msu.edu> Subject: Early SF; How early? Bill and Mark discuss; >>>>The *Somnium* may be said to be the earliest "hard-science" SF story: >>>>one which hews closely to the line of contemporary science. >>> I'd say Dante's _Divine Comedy_ has it beat by about three centuries. >Oh, I don't have any problems with describing Kepler's work as hard SF; >my quibble was over whether it's the *first* such work. >>How good is the case for Dante? [...] >More than that, however, the entire work is an exploration of the cosmos >as it was then understood. Certainly Dante invented lots of things, >but because our own science paints such a different picture of the >world we are likely to mistake for fantasy things which Dante took >from the soberest contemporary accounts of how the universe worked >(for example, the angelic beings which guide each planet in its sphere). >[...] If this is the standard, then I'd say that Homer beat them all to the punch with _The_Odyssey_, c. 500b.c. or older. Or maybe the Vedas, except the authors would probably bristle at the 'fiction' part :-) -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: 7 Jun 1993 00:45:17 GMT From: Jeff Bytof - SIO Subject: fresh lamb, anyone? Newsgroups: sci.space > In advance of that report, a NASA official clost to the redesign > process spoke with reporters Saturday on condition that he not > be identified publicly. The anonymity enabled him to speak with > unusual candor for a government official. > > "We never told the American people really how much the space > station would cost", he said. > > That was vindication for congressional critics and other > analysts, such as the GAO, who have said for years that > NASA sold its big programs to Congress by fudging on their > costs. So now that NASA has spilled the beans, will the bean counters be any happier? What Clinton needs right now, real bad, is a sacrificial lamb, and I'll bet he smells blood right now! -rabjab ------------------------------ Date: Mon, 7 Jun 1993 00:18:43 GMT From: "Phil G. Fraering" Subject: How would we get back to the moon, if we had to? Newsgroups: sci.space prb@access.digex.net (Pat) writes: >In article pgf@srl03.cacs.usl.edu (Phil G. Fraering) writes: >|prb@access.digex.net (Pat) writes: >| >|>Propulsion hasn't changed at all since the 50's. >| >|Uh, the LM's were built in the 60's. And I have to ask: are they >|assuming storable propellants? >| >Yes, but it was still vintage 50's propulsion approaches. >|>Electronics are much better, but you don't need much if you look >|>at voyager.(for landing and descent control) >| >|I am unaware of any landing options for Voyager. The best it >AAARRGGHHH Viking.... damn, i hate when my make that kind of slip. Viking isn't a good point of comparison for a lunar lander; it made extensive use of aerobraking. Doubtless Henry knows more about the descent thrusters, but I think they were just braking thrusters with a preprogrammed thrust profile. They weren't aiming at a good landing site so much as an area they hoped would have good landing sites.}wD And they missed, in a way: if {_one of the landers came down on {_a nearby boulder... But with the new electronics,~r this may not be a problem even for unmanned landers. >pat -- +-----------------------+"Somewhere in the back of her mind, she had always |Phil Fraering |had a vision of the Slowness as a stifling darkness |pgf@srl03.cacs.usl.edu |lit at best by torches, the domain of cretins and +-----------------------+mechanical calculators." - Vernor Vinge, _A Fire Upon the Deep_ ------------------------------ Date: Mon, 07 Jun 93 00:34:31 EDT From: Tom <18084TM@msu.edu> Subject: Loudmouths or policy-makers? Allen sez; > Members of this forum have played important roles in >public policy. Phone calls and letters from readers has kept NASP, >SSTO, and perhaps even Freedom alive over the years. I'm posting pretty late to this, but it still applies. Thanks, Allen. I'm not much in favor of the gov-subsidised system, but given that it exists, it's good to know we actually have influence on how our taxes are spent. -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: 6 Jun 1993 22:02:22 -0400 From: Pat Subject: manifest destiny = US getting uppity again Newsgroups: sci.space In article pgf@srl03.cacs.usl.edu (Phil G. Fraering) writes: |Very well, Henry, you give me no choice. I didn't want to do something |this destructive, even to save the nation, but your threat of destroying |the NASM gives me no choice. | Is it me, but isn' t Defcon 5 peace, or is that Defcon 1?????? |Operation Casino Royale Storm has been put on Defcom 5 status. Anything |remotely suspicious happens, it'll go to 6. | |(For those of you who don't know, this is a special sealed railway |car equipped with slot machines, roulette tables, etc., all designed |to keep the occupant, Edwin Edwards, occupied while it rolls to |Quebec, where it shuts down and disgourges its passenger. Then |the real destruction begins.) Who'se He? ------------------------------ Date: 7 Jun 93 06:11:20 GMT From: Michael Sandy Subject: manifest destiny = US getting uppity again Newsgroups: sci.space By the way, if by some chance some deranged Canadians _do_ seize the North Dakota arsenal and vape DC, and the NSA arrests us all as coconspirators, I'll be _very_ very upset! :+) Howver, Canada has enough internal problems with Quebec and the Provinces to deal with Chicago, let alone the whole North American continent. -- Michael Sandy michaels@m2xenix.psg.com "I resolve to make no non-tautological New Year's Resolutions!" ------------------------------ Date: 7 Jun 93 06:06:54 GMT From: Michael Sandy Subject: manifest destiny = US getting uppity again Newsgroups: sci.space *sigh*, a pity, but all the people you'd most want to be in Washington come the Revolution, (apologies to Douglas Adams), their backs won't be against the wall but in a civil defense bunker. By the way, I _like_ the National Aerospace Museum, which happens to be smack dab in the middle of your crosshairs. :+) We need xssomething a little more selective. How about a more incapicitating version of larangitis? Or maybe a plague whose vector is Washington Lobbyists. Seriously, if you found yourself in a Lunar city with a mass driver and a map of the World,, what would you do? If you had some alien weapon that could level cities from a continent away, what great altruistic of selfish things would you do? Would you carve a Smily Face in the Moon? Blackmail AllState insurance? Demand the Home phone number of your favorite actor, actress, unfavorite politician, etc... What would you do if you discovered a new power source which could do all that? Would you want in put under control and/or exploited for mankind and your own benefit? Suppose with a loop of super conducting wire, a mass driver, and some hyper magnetic alloy you could create a thermonuclear explosion with common tap water What happens if all the dreams of space-lovers came true but we weren't mature enough to trust other human beings with it? -- Michael Sandy michaels@m2xenix.psg.com "I resolve to make no non-tautological New Year's Resolutions!" ------------------------------ Date: Mon, 7 Jun 1993 01:30:31 GMT From: "Phil G. Fraering" Subject: mass drivers Newsgroups: sci.space dietz@cs.rochester.edu (Paul Dietz) writes: >The longtitudinal velocity is less important, btw, as the mass driver >would be put in a place where its error matters only to second order. You're right; I confused longtitudinal and lateral velocity... > Paul F. Dietz > dietz@cs.rochester.edu -- +-----------------------+"Somewhere in the back of her mind, she had always |Phil Fraering |had a vision of the Slowness as a stifling darkness |pgf@srl03.cacs.usl.edu |lit at best by torches, the domain of cretins and +-----------------------+mechanical calculators." - Vernor Vinge, _A Fire Upon the Deep_ ------------------------------ Date: 6 Jun 1993 22:05:19 -0400 From: Pat Subject: mass drivers Newsgroups: sci.space Couldn't you put just small thrusters on th give it slight mid course corrections? pat ------------------------------ Date: 7 Jun 93 02:28:19 GMT From: Paul Dietz Subject: mass drivers Newsgroups: sci.space In article <1uu7ov$a29@access.digex.net> prb@access.digex.net (Pat) writes: > Couldn't you put just small thrusters on th give it slight > mid course corrections? That kind of defeats the whole purpose. Remember, this thing is supposed to be launching millions of small (on the order of kilograms) packages per year. Those packages have to be dumb as regolith to have a hope of it being affordable. Paul ------------------------------ Date: Mon, 7 Jun 1993 01:38:35 GMT From: John Fleming Subject: Moon Base Newsgroups: sci.space Let's see if some context can be brought into this stimulating discussion. A couple of months ago, I saw on TV some fancy space hardware fail and so 3 guys had to go out and grab a satellite by hand. Hardware that was designed and built by the so-called experts in this sort of thing. I guess that means no one is "expert" in desiging working mechanisms in microgravity conditions. Second. A few months ago Space News had an interview with Chris Kraft, where he said (paraphrasing) that anything we do in space with humans, such as going to the Moon or Mars, will be done with technology that hasn't yet been developed. Apollo was single string, and if we went back to the Moon today, it would still be single string. And anyone who doesn't think it was (and would be) extremely risky doesn't know what they are talking about. Backup doesn't mean more of the same. It means a true, reliable alternative, based on a different technology, that you know will work. An alternative you can trust. The backup to Apollo technology was the pinnacle of Homo Sapiens technology, the smartest, quickest, most alert people we could send into space, and monitor and command equipment with on the ground. This thread has been discussing the relative merits of Asteroid/Comets vs. Lunar raw material sources. I say, this is a silly argument. WE DON'T KNOW, and won't until we go. So don't talk about bogus merits, instead figure out how to get there and start evaluting potential technologies How do we find out? We send many _cheap_ pilot projects to both places. I don't trust NASA with $5B for a brobdinagian mega-program. But I bet we could funds lots of $50M successful "enabling" technologies demonstrations. *THAT* is what NASA is about. A good reason that NASA got to do Apollo was because they could build hardware and produce real results in aeronautics. Before NASA gets another big project, they are going to have to show us that they can produce little results. They expended their public capital with Shuttle, HST, and SSF. No one believes NASA can do anything right and keep the costs in line. So it is rebuilding time. Enabling technologies is NASA's rightful business. Full-employment national projects aren't necessarily. Here is my guess at what will happen. The stuff we send to the moon will at first work better and give us more results. Why? Because the moon has gravity, and our gravity-biased mechanisms designed by gravity-biased engineers will work. The moon will drive enabling technologies of automation, vacuum processing, and operations/maintenance. But the Asteroid/Comet program will in the long run pass the moon, and that is where we will make our money. The problem with Comets is that we don't know doodly-squat about how to process materials in zero-G. The Comet program will be starting from farther back, with more unknowns, but will eventually surpass the gains of the Moon because we won't have to lift out of a gravity well, and it's always daylight in space. Not so for the moon. Little projects don't weigh a lot, so the relative costs of Moon vs. asteroids aren't as important. Right now, the turnaround time from launch to operation will be much faster for the moon. And we need results more than anything. With lots of little projects, you build a constituency of diverse interests. It is more real, because you are closer to the hardware, the action, the results. You build the equipment with your own hands and mind, you control it yourself, and you explain the results. You are much more intimately involved than when with a mega-project, where each person has only one tiny cog, and only a chosen few get any real responsibility. From that diverse and energized base will come the group of people capable of scaling up to real projects and making money. So send the orbiting Geologic Explorers to the Moon, find the good deposits of water and carbon, and send our demonstrations there. Send a sniffer to L4 and L5, looking for captured material. Send a pissant lander/prospector to likely comets, not some JPL full-employment mega-explorer larded with the latest super instruments since it is the only ride going for a generation. It is almost as if JPL forgot how to build explorers, somewhere between Surveyor and Galileo. Don't shoot me for being the messenger. If the public thinks you haven't got what it takes anymore, it doesn't matter whether that perception is justified or not. It is incumbent on you to find a way to change the public's opinion. And the public only wants results, not might-have-beens. I'm sure I will get comments to the effect: "but we already have the technology, and we know how to do it", from both camps. I say no. Remember Chris Kraft. We don't have the technology. Take it from someone who has built and operated modest space hardware. Most non-production space hardware we launch sucks. It never works quite like we predict. The reliability is terrible. We need a better knowledge base. We need to know how to build space hardware that we are confident will work the *first* time. Commercial space hardware works because they have a 30-year train of incremental design changes. Some of those design changes didn't work. For the Moon and comets, we have view-graph engineering and basic chemistry. It isn't technology until the demonstration systems are working and pumping out material. If you say "let's build a mega-project", you are doomed to fail. Not only do you have to assemble a jigsaw puzzle, but right now you don't know how to evaluate the pieces lying on the floor to determine whether they belong to the puzzle. That is why I support Dan Goldin. Better, faster, cheaper. I as much as anyone want to see my stuff go to the Moon and comets. Hell, I want to go to the Moon myself so bad I ache every time I look at it. But face it. Our generation will only get to design and build the itty-bitty pilot projects. But don't worry. It is our children who are going to go in force and make money from it. I think we had better get started. Thanks for staying with me this far. What are the enabling technologies we need that we need demonstrations and pilot projects for on the Moon and comets? Let's start a list. Automated replication of dumb hardware in Moon/zero-g Integration of dumb hardware with electronics from earth. Metal forming on the Moon/microgravity. L4/L5 material sniffing/cataloging Moon/Comet remote prospecting Volatiles capture and differentiation Automated volatiles processing Excavation and transport of dirt Periodic maintenance, BIT, and recognition of impending failure Comet prospecting Keeping vacuum conditions. Capture/recycling of process materials General mechanisms (...put your favorite here...) New and different technologies that need demonstrations are like the micro-robots at MIT. Until we send them, we won't know whether they will work. The Moon, comets, and zero-g are too different to blandly assume that because it works on Earth ... Let's go! John A. Fleming | In the difficult years that lie ahead, we Motorola Satellite Communications | must remember that the snows of Olympus John_Fleming@sat.mot.com | lie silently beneath the stars, waiting | for our grandchildren. - Arthur C. Clarke ------------------------------ Date: Mon, 7 Jun 1993 02:11:35 GMT From: James Salsman Subject: SETI: viral mediums and Ukranian radio astronomy Newsgroups: alt.sci.planetary,sci.space,sci.astro In article <1993Jun6.232242.7432@sfu.ca> Leigh Palmer writes: >In article <1993Jun6.204023.25847@eecs.nwu.edu> James Salsman, >bovik@eecs.nwu.edu writes: >>According to the tranlation of the abstract, there are four stars >>within 20 parsecs that are "solar-type" and also are in the same >>direction as "continous isotropic radioemmision" sources in the >>hundred to thousand megahertz range. The probability of such >>emmissions being accidental was declared to be 2x10^-4. > >While I suspect this is simply a crackpot article, I can correct >one erroneous calculation. The probability of any given star being >in the same direction as continuous isotropic radio emission is >not 2x10^-4. Since isotropic emission comes from all directions >the probability of any given star being in one of those is unity. The >probability of it being in all of them is zero. I put "continous isotropic radioemission" in quotation marks because that was the phrase used in the English translation of the abstract, which apparently was done by a Russian using the word "isotropic" in some other than the most common English sense. My Russian-speaking friend and the dictionaries I used did not recognise the Russian word used, and if you are fluent please order a copy of the report from the NTIS and provide the net with the true meaning. The author of the report stated in Russian that there was one chance in 5000 that the signals were natural. The English abstract, on the other hand, said that there was a probability of 2x10^-4 that the signals were "accidental." The abstract was simply not well translated. What makes you think that my article was simply a crackpot? -- :James Salsman ::Bovik Research Dear Tipper, please help start Divorce Education programs for parents of minors ------------------------------ Date: Mon, 7 Jun 1993 00:58:37 -0400 From: George Gusciora Subject: That Salsman Guy Newsgroups: cmu.cs.opinion A fresh posting from sci.astro: Looks like the good old vintage stuff which made him famous, me thinks. Nice one, James. These astonomy guys don't read the Hacker Dictionary. X-Andrew-WideReply: netnews.alt.sci.planetary,netnews.sci.space,netnews.sci.astro X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Received: via nntppoll with nntp; Sun, 6 Jun 1993 17:22:05 -0400 (EDT) Path: andrew.cmu.edu!bb3.andrew.cmu.edu!news.sei.cmu.edu!magnesium.club.cc.cmu.e du!pitt.edu!uunet!news.cstar.andersen.com!news.acns.nwu.edu!nucsrl!bovik From: bovik@eecs.nwu.edu (James Salsman) Newsgroups: alt.sci.planetary,sci.space,sci.astro Subject: SETI: viral mediums and Ukranian radio astronomy Summary: this post replaces a cancelled post because Bob Arnold *does* have an email address after all. Message-ID: <1993Jun6.204023.25847@eecs.nwu.edu> Date: 6 Jun 93 20:40:23 GMT Followup-To: alt.sci.planetary Organization: BRI Lines: 98 Xref: bb3.andrew.cmu.edu alt.sci.planetary:980 sci.space:10481 sci.astro:7105 These references and notes are a repost of something I had to cancel in order to keep a mailbox that I didn't know existed from getting deluged. Sorry if you see it twice. :James ----- "Is Bacteriophage \phi X174 DNA a Message from an Extraterrestrial Intelligence?" Hiromitsu Yokoo and Tairo Oshima, _Icarus_ vol. 38, pp. 148-153 (1979.) "SV40 DNA---A Message from \epsilon ERI?" Hiroshi Nakamura, _Acta_Astronautica_, vol. 13, No. 9, pp. 573-578 (1986.) ----- This information is from a technical report written by A. V. Arkhipov of the Akademiya Nauk URSR Kharkov Institute of Radio-Physics and Electronics in the Ukrane. The Arkhipov article is available from NTIS under the report number INIS-SU-25/A. It was published in 1986, but has not yet been translated by any of the American SETI labs that I have contacted. According to the tranlation of the abstract, there are four stars within 20 parsecs that are "solar-type" and also are in the same direction as "continous isotropic radioemmision" sources in the hundred to thousand megahertz range. The probability of such emmissions being accidental was declared to be 2x10^-4. This information below was gleaned from the text, with the help of several European star catalogs and a technical Russian-English dictionary from the Carnegie-Mellon University Engineering and Science Library, the SIMBAD database, courtesy S.A.O./Harvard and a friend from Pittsburgh fluent in Russian (Thanks, Inna!) These are the four stars that Arkhipov says are the probable locations of extraterrestrial civilazations: Catalog Right (1950) Dec- Visual Absolute Spectral Distance Radial Number Ascention lination Magnitude Type (light Velocity ======== ========= ======== ====== ======== ======== =years)= =(km/s)= HD 21899 3h28m27s -41d 32' 6.11 6.60 F6V 39.3 +16.2 or HR 1076 or GC 4199 (In southern Eridanus, near the 4th mag. y Eridani) HD100623 11h32m03s -32d 34' 6.06 6.00 dK1V 33.1 -23 or HR 4458 or GC 15873 or DM-32 8179 (In middle Hydra near Zeta Hydrae) HD187691 19h32m03s +10d 17' 5.16 3.75 dF8V 68.0 -1 or Omicron Aquillae or CG 27480 or GL 768.1A or 54 Aql (Just north of Altair) HD187923 19h49m43s +11d 30' 6.15 3.1 G0V 135.9 -17 or HR 7569 or GC 27510 (Just about twice as far north of Altair) Here are the frequencies at which these stars were said to emit continous isotropic and/or periodic radioemmissions: Star Signal (MHz) Current (see note) ========= ============ ================== HD 21899 408 1.64 +or- 0.17 2700 0.19 +or- 0.03 HD 100623 408 0.86 +or- 0.05 1415 0.13 +or- 0.03 (In the Waterhole Band) 2700 0.21 +or- 0.02 HD 187691 178 2.4 +or- 0.5 408 0.85 +or- 0.05 HD 187923 178 2.4 +or- 0.5 408 2.02 +or- 0.77 1420 2.8 +or- 1.0 (In the Waterhole Band) 3200 <0.5 Note: I am not sure what units "current" is being expressed in. Neither the Russian-English dictionary that I consulted or my Russian-speaking friend could help me figure out the discussion of this unit, which apparently included thermodynamics as well as electromagnetic technicalities. The Cyrilic symbol used for this unit looks like . The waterhole band is that area of the radiofrequency sprectrum between the primary emission lines of H and OH, which many scientists think would be indicative of water, and therby life, and therefore an ideal place for interstellar communications. On a related note, I think that all of Arkhipov's stars are emitting at 408 MHz is remarkable. Maybe he only had a few settings on his tuner. -- :James Salsman ::Bovik Research Dear Tipper, please help start Divorce Education programs for parents of minors ------------------------------ Date: 6 Jun 1993 22:21:34 -0400 From: Pat Subject: Why are SSTO up-front costs rising? Newsgroups: sci.space Actually many of NASA's small Space projects also do extra-ordinarily well. COBE, MAGELLAN, Voyager, PVO, VIKING.... all did great too. what happens as a project gets bigger, it starts looking around for political support. in order to do that, it starts branching out to more science communities. look at galileo. or HST. if they were small 200 million dollar projects, they wouldn't need lots of support and have lots of experiments. as teh instruments increase, it forces increasing rounds of re-design, and mediocratization of design. pat My theory, is if HST had only the FOC, it'd have flown in 1981. ------------------------------ id AA02692; Sun, 6 Jun 93 19:42:11 EDT Received: from CRABAPPLE.SRV.CS.CMU.EDU by VACATION.VENARI.CS.CMU.EDU id aa22410; 6 Jun 93 20:37:44 EDT To: bb-sci-space@CRABAPPLE.SRV.CS.CMU.EDU Xref: crabapple.srv.cs.cmu.edu sci.space:64201 Path: crabapple.srv.cs.cmu.edu!fs7.ece.cmu.edu!europa.eng.gtefsd.com!darwin.sura.net!news-feed-1.peachnet.edu!concert!rutgers!rochester!dietz From: Paul Dietz Newsgroups: sci.space Subject: Re: mass drivers Message-Id: <1993Jun7.002904.24113@cs.rochester.edu> Date: 7 Jun 93 00:29:04 GMT References: <25140@mindlink.bc.ca> Organization: University of Rochester Computer Science Dept Lines: 38 Sender: news@CRABAPPLE.SRV.CS.CMU.EDU Source-Info: Sender is really isu@VACATION.VENARI.CS.CMU.EDU In article pgf@srl03.cacs.usl.edu (Phil G. Fraering) writes: >>dietz@cs.rochester.edu (Paul Dietz) writes: >>> However, remember that the acceleration portion was only one part of the >>> system: there was also to be a part downstream of the accelerator where >>> (lateral) velocity errors were measured and corrected. I've always had the >>> impression that was one of the more problematic parts of the system (the >>> mass catcher at the far Lagrange point was another). >>wind measurements, etc. > >*Sigh*... > >SSI eventually fixed this problem in Mass drivers II and III by >setting it up so that the coils only _pulled_ the bucket, making the >center of the assembly a point of stable equilibrium instead of >unstable equilibrium. (I may have the phrasing wrong.) ' I think you're confused, Phil. The pull-only scheme enabled them to use the drive coils to center the buckets, allowing them to achieve 1000 Gs of acceleration. However, this scheme would not achieve the lateral velocity control needed to put payloads into a mass catcher at the far Lagrange point (and, remember, the precise velocity needed to do this will change as the moon moves relative to the earth and sun). Control of lateral velocity to within less than 1 millimeter per second would be necessary to keep the mass catcher from being unacceptably large. A subsequent feedback stage would be needed to correct these errors. An electrostatic scheme was suggested. Measuring these errors requires precise tracking down a path of tens of kilometers. The longtitudinal velocity is less important, btw, as the mass driver would be put in a place where its error matters only to second order. Paul F. Dietz dietz@cs.rochester.edu ------------------------------ End of Space Digest Volume 16 : Issue 696 ------------------------------