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 ; Wed, 14 Feb 90 01:27:46 -0500 (EST) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Wed, 14 Feb 90 01:27:20 -0500 (EST) Subject: SPACE Digest V11 #40 SPACE Digest Volume 11 : Issue 40 Today's Topics: Re: SPACE Digest V11 #39 Subscription addition/removal Energy (was Re: Spacecraft drives and fuel efficiency) Fun Space Fact #1: Launcher Development Costs Re: metric vs. imperial units Re: Space Station Costs Re: metric vs. imperial units Re: Kepler fudged the Numbers? Soyuz TM-9 docks with Soviet Mir Space Station Re: Recreation in Space Re: Kepler fudged the Numbers? SPACE Digest Subscription ESA Publications Division ---------------------------------------------------------------------- Date: Tue, 13 Feb 90 8:20:43 EST From: Jerry Subject: Re: SPACE Digest V11 #39 Please remove me from your mailing list. ------------------------------ Date: Tue, 13 Feb 90 16:15:10 -0500 (EST) From: Kevin William Ryan To: DXCOD@WIDENER.BITNET, Space Subject: Subscription addition/removal Send to space-request, not to space. Most of the digests are prepared by automated digest software, and the moderator might miss such requests. The space-request@andrew.cmu.edu address goes directly to the moderator. kwr "Jest so ya know..." P.S. Again - all requests for addition/deletion on the space digest mailing list should be directed to space-request@andrew.cmu.edu in order to reach the moderator. ------------------------------ Date: 13 Feb 90 19:38:50 GMT From: rochester!dietz@louie.udel.edu (Paul Dietz) Subject: Energy (was Re: Spacecraft drives and fuel efficiency) A couple of minor corrections: 4e26 watts is enough power to launch a 30 million ton spacecraft to .5 c once per second, not 15 million tons. Also, the kinetic energy of a 10 km asteroid going at 20 km/s is about 80 teratons, not 20. Exercise for the day: if you wanted to blast the atmosphere off Venus in preparation for terraforming, how much antimatter would you need? If you use fusion bombs, how much deuterium? Paul F. Dietz dietz@cs.rochester.edu ------------------------------ Date: Tue, 13 Feb 90 14:24:02 PST From: mordor!lll-tis!ames!ucsd!pnet01.cts.com!jim@angband.s1.gov (Jim Bowery) To: crash!space@angband.s1.gov Subject: Fun Space Fact #1: Launcher Development Costs The Shuttle cost around $(1990)30 Billion to develop and it doesn't work very well. The American Rocket Company (AMROC) cost about $(1990)30 Million to start up and it developed a launcher that is likely to work very well. That's a factor of ONE THOUSAND less. I wonder what would happen if you just passed out one thousand chunks of money at $30 million a crack to anyone who looked vaguely like they had an idea about how to build a better launcher (and, of course, kept them away from metropolitan areas :-). --- Typical RESEARCH grant: $ Typical DEVELOPMENT contract: $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ ------------------------------ Date: 13 Feb 90 16:56:29 GMT From: snorkelwacker!usc!jarthur!jokim@bloom-beacon.mit.edu (John H. Kim) Subject: Re: metric vs. imperial units In article <1294@otc.otca.oz> gregw@otc.UUCP (Greg Wilkins) writes: > >The whole point is that metric has many big points in its favour: > > - To some extent, when designing physical systems, recurring decimal > places can be avoided, hence round off errors can be reduced. Gee. Why don't we just switch to Gaussian units then? :-) -- John H. Kim | (This space to be filled when I jokim@jarthur.Claremont.EDU | think of something very clever uunet!muddcs!jarthur!jokim | to use as a disclaimer) ------------------------------ Date: 13 Feb 90 16:48:05 GMT From: zaphod.mps.ohio-state.edu!swrinde!cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo!henry@tut.cis.ohio-state.edu (Henry Spencer) Subject: Re: Space Station Costs In article <708@shodha.dec.com> pflueger@thewav.enet.dec.com (Free speech is a sound investment) writes: >[Following along on the thread about the cost of LLNL's space station > (and lunar base)] > >What about LLNL's idea? Is it plausible? Cost effective? The jury is still out on it. NASA claims the technology is decidedly optimistic; LLNL counterclaims that virtually all the technology is from NASA's own past efforts. (The figures on inflatable structures come from the folks who make NASA spacesuits, for example.) The cost figures are probably over-optimistic -- cost estimates at this stage always are -- but it does seem like it would be worth a try. It's not likely that it will get a chance unless it is rammed down NASA's throat by higher management. Just going ahead and *doing the job*, forgetting all the crap about new technology and advanced robotics and 57 unmanned preliminary missions, may sound attractive to space enthusiasts, but the reaction from the NASA facilities and contractors -- who together have a lot of political clout -- will be basically "sounds like less money for us -- we're against it". >Didn't the VP meet with those folks awhile back? What was the outcome? So far the only real outcome has been some ringing speeches about the need to give more attention to outside ideas, with veiled hints that NASA may not have the final say quite as often as it would like. Nothing very concrete yet. >Should we develop the idea in paralell (sp?) and let the best proposal win?? That would be a great idea except that Congress doesn't especially like funding parallel efforts and all the Space Authorities (i.e. NASA) will be against it on the off-chance that LLNL might win. -- "The N in NFS stands for Not, | Henry Spencer at U of Toronto Zoology or Need, or perhaps Nightmare"| uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 13 Feb 90 08:51:15 GMT From: eru!luth!sunic!mcsun!ukc!acorn!ixi!clive@bloom-beacon.mit.edu (Clive Feather) Subject: Re: metric vs. imperial units In article <1990Feb12.010632.12891@sics.se> pd@sics.se (Per Danielsson) writes: >I'm quite sure that aviation in Australia uses feet for altitudes and >nautical miles for distances, just as the rest of civilian aviation in >the world (with a few exceptions: the USSR being the one really >important one, but Russian pilots have to use feet and nm when they >fly outside the USSR ...). Equally, British Airways pilots have to use metres when flying trans-Soviet sectors (London-Hong Kong, London-Moscow, Moscow-Tokyo, etc.). The flight-engineer has a little card with three columns on it: m feet 305 1000 3281 610 2000 6562 etc. -- Clive D.W. Feather | IXI Limited | +44 223 462 131 (v) clive@ixi.co.uk | 62-74 Burleigh Street | +44 224 462 132 (fax) ...!uunet!ixi!clive | Cambridge U.K. |----------------------------- | CB1 1OJ | Silly quote being thought up ------------------------------ Date: 13 Feb 90 16:47:35 GMT From: brutus.cs.uiuc.edu!uakari.primate.wisc.edu!uflorida!mephisto!prism!ccastdk@apple.com (Lancelot du Lac) Subject: Re: Kepler fudged the Numbers? In article <9233@cbnewsm.ATT.COM> mls@cbnewsm.ATT.COM (mike.siemon) writes: >In article <1990Feb12.133056.9826@bank.ecn.purdue.edu>, >cyliax@bank.ecn.purdue.edu (Ingo Cyliax) writes: > >>I always thought he made several mistakes in his math, some of which cancelled >>each other out. From what I heard, no. What he did was make several mathematical errors that caused him to mistakenly reject the correct answer, then went back quite a while later and re-figured. (More on this particular point in a moment) >it turns out the every point on the orbit so given is in fact >given *exactly* by Kepler's ellipse formulae This (by my information) is due to the fashion in which he solved the problem. Trial and error. My understanding, is that he would Compute a possible orbit, calculate what the positions Mars would be in for the time points he had, and then check his computations against the data gathered by Brache. He would then adjust the orbit to minimize error, recalculate and recompare. Much like the Newtonian approximation. And, like the approximation, it is possible given enough time to get an arbitrarily accurate solution. One would, however, stop when one reached the error values of the observational data. Kepler, being somewhat of a perfectionist, would naturally ascribe the minimum possible error to Tycho Brache's data, so that he could get the maximum possible accuracy. >Having seen only the journalistic account, I have no real opinion here; I >would guess that the translator noticed a remarkable *lack* of observational >error -- and presumably Kepler was too troubled by residual differences from >his ellipses that he couldn't account for, so he decided not to bother his >readers with this problem. A possibility, but remember, that Kepler's three Laws were based on Tycho Brache's data and his own ellipses. It is all but impossible (save by sheerest coincidence) to accurately describe formulae and general cases and formulate laws which yeild accurate predictions (which Kepler's did) when all of these are based on data that one has fudged. -- David Kidd - Georgia Tech | "Oh, I feel like such a pompus uucp: ...!{decvax,hplabs,ncar, | twit!" purdue,rutgers}!gatech!prism!ccastdk| Internet: ccastdk@prism.gatech.edu | "It's what you do best, my love." ------------------------------ Date: Tue, 13 Feb 90 18:35:08 EST From: Glenn Chapman To: <@cunyvm.cuny.edu:SVAF524@utxvm.BITNET>, biro%hydra.enet.dec.com@decwrl.dec.com, klaes%wrksys.dec@decwrl.dec.com, lepage%vostok.dec.com@decwrl.dec.com, space-editors-new@andrew.cmu.edu, yaron@astro.as.utexas.edu Subject: Soyuz TM-9 docks with Soviet Mir Space Station The Russian's Soyuz TM-9 capsule successfully docked with their Mir space station this morning, Feb. 13th, some two days after its Feb. 11th launch. On board were Anatoly Solovyov and Alexander Balandin, who will be staying up there for a six month mission. They were greeted by Alexander Viktorenko and Alexander Serebrov who have now been in orbit for 161 days. Television pictures of the docking were carried on Vermya (the Soviet nightly news) indicating the docking was to the Kvant 1 module at the rear of the station, as expected. When the hatch was opened the new cosmonauts appeared to enter a rather spacious section of Mir/Kvant1/2, with one of the long duration crew holding what appeared to be a bouquet of flowers (the traditional greetings for a traveller is bread, salt and flowers). All the cosmonauts floated around a table, though their voices were not heard on camera. Viktorenko and Serebrov appeared to be in good shape. They will be coming down in about one week according to the announcement, in keeping with the Feb. 20th date mentioned in my last posting, not the original Feb. 24th plans. It will also mean that both cosmonauts will be about 5 to 7 days short of one half year accumulative time in space when their previous missions are added in. (Radio Moscow & Moscow TV, Feb. 13) Some interesting comparisons were released between the NASA's Manned Maneuvering Unit and the Soviet's space bicycle, also called SPK, or Icarus, that Viktorenko an Serebrov tested twice earlier this month. Its Russian system's mass is 200 Kg (440 lbs.) about 25% heavier than the 148 Kg (325 lbs.) MMU. However, its top velocity is 30 meters per second or 108 Kph (98 ft/sec or 66 mph), more than twice that of the 14 m/sec or 49 Kph (45 ft/sec or 31 mph) of the US MMU. This suggests that the compressed nitrogen gas load is about 31 Kg (68 lbs), compared to 11.8 Kg (26 lbs) on the MMU. This calculation assumes the same mass of man and suit, and same gas pressure, obviously rather rough values. All things being equal that means the Soviet system should be able to operate at about 2.2 times the maximum safe distance of the MMU 's 137 meters (450 ft) or say 300 meters (990 ft). The fact that this is a nice round number metric number suggests that it may be the design distance. (Space News Feb. 5) One point to note is that the leaving date for the Soyuz TM-8 crew will be the fourth anniversary of the orbiting of Mir. On May 29th this new crew will see Mir become the longest lasting operational space station, exceeding Salyut 7's 4.2 years. At that point Mir will be in every respect the earth's most successful space station. Glenn Chapman MIT Lincoln Lab ------------------------------ Date: 13 Feb 90 23:35:12 GMT From: shelby!portia!izahi@decwrl.dec.com (Raul Izahi Lopez Hernandez) Subject: Re: Recreation in Space In article <9@soleast.Solbourne.COM> turner@soleast.Solbourne.COM (James Turner) writes: >henry@utzoo.uucp (Henry Spencer) writes: > >>In article <476@sixhub.UUCP> davidsen@sixhub.UUCP (bill davidsen) writes: >>> Let me give you a hint... if I were going to be on a multiyear >>>mission, I would want female astronauts. > >>I dimly recall seeing an account from one of the Skylab astronauts which >>commented on this. :-) He said that NASA told them they had a mass >>budget of 60-odd kg for recreation, and "after management rejected our >>unanimous first suggestion", this was used on games, tapes, etc. >Actually, I suspect that if the additional 60kg had represented the entire >weight of a Recreational Coupling Mate/Demate Facility (RCMDF), they would >have given the OK. Unfortunately, you have to factor in N times the RCMDF's >weight in O2, food, water, and other life-support trivia. Sorry guys, I don't like to joke if there is one. I'm aware that this is a mostly male community but I don't agree with even the smallest hint of sexism here or anywhere else. I was talking with some friends about the origin of thiking and if it happened to one individual long ago in a primitive community, I want to believe it happened to a woman who had a dominant genetics and then "smart" people were born afterwards. I'm really happy to see that everyday more women are involved in space science both as astronauts and as scientists. So everybody keep up the good work. RAUL IZAHI |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| Raul Izahi Lopez Hernandez izahi@portia.stanford.edu Graduate Student, EE Dept. "Nun, ich war und ich bin noch Student, Stanford University denn ein Student bleibt ewig Student!" -DG ------------------------------ Date: 13 Feb 90 04:27:31 GMT From: att!cbnewsm!mls@ucbvax.Berkeley.EDU (mike.siemon) Subject: Re: Kepler fudged the Numbers? In article <1990Feb12.133056.9826@bank.ecn.purdue.edu>, cyliax@bank.ecn.purdue.edu (Ingo Cyliax) writes: > I always thought he made several mistakes in his math, some of which cancelled > each other out. That's the old Koestler (_Sleepwalkers_) line. The new report (bruited in the NY Times Tuesday science section a few weeks ago, for example) is from the person who is undertaking a current scholarly translation of his work. The translator says that, in attempting to follow out in detail the complex trigonometric computations that Kepler *says* he did on the basis of Tycho's data (there is an excellent elementary discussion of this in a Dover book by Ryabov that I remember from some 30 years ago, without having it on hand to reference) it turns out the every point on the orbit so given is in fact given *exactly* by Kepler's ellipse formulae -- i.e., he generated the points he "knew" were correct and constructued pseudo-observational data to support that. Having seen only the journalistic account, I have no real opinion here; I would guess that the translator noticed a remarkable *lack* of observational error -- and presumably Kepler was too troubled by residual differences from his ellipses that he couldn't account for, so he decided not to bother his readers with this problem. It all goes to confirm my impression that the only people who actually *read* scientific reports in detail are graduate students who have to give seminar papers on them :-) -- Michael L. Siemon In so far as people think they can see the cucard!dasys1!mls "limits of human understanding", they think att!sfbat!mls of course that they can see beyond these. standard disclaimer -- Ludwig Wittgenstein ------------------------------ X400-Trace: US*ATTMAIL*WIDE; arrival Tue, 13 Feb 90 10:45:43 -0500 action Relayed Date: Tue, 13 Feb 90 10:45:43 -0500 P1-Message-Id: US*ATTMAIL*WIDE; 5A020D0A2C0D0067-MTABWIDENER Ua-Content-Id: 5A020D0A2C0D0067 From: DXCOD%WIDENER.BITNET@vma.cc.cmu.edu Subject: SPACE Digest Subscription I seem to be unable to get off of this list. Any suggestions? Thanks...Chuck Darney ------------------------------ Date: 13 Feb 90 09:02:56 GMT From: mcsun!hp4nl!phigate!prle!prles2!cstw10!munk@uunet.uu.net (Harm Munk) Subject: ESA Publications Division A few weeks ago someone mentioned the ESA Publications Office as the place to get a subscription to ESA Journal and ESA Bulletin. However, the address in the posting was incorrect (outdated ?). Here follows the correct address: ESA Publications Division P.O. Box 299 2200 AG NOORDWIJK The Netherlands ------------------------------ End of SPACE Digest V11 #40 *******************