Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from middletown.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl) (->ota+space.digests) ID ; Fri, 30 Sep 88 15:22:29 -0400 (EDT) Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Fri, Sep 30 88 15:21:49 EDT Subject: SPACE Digest V8 #384 SPACE Digest Volume 8 : Issue 384 Today's Topics: Re: Chix in Space Dinosaur killer impact sites? Re: Possible Disaster Scenarios Re: Chix in Space Re: Possible Disaster Scenarios Re: Possible Disaster Scenarios Re: NASA and McDonnell Douglas sign commercial launch agreement (Forwarded) Re: Alien civilizations, improved grey goo, and biotech civilizations... Re: Are we ready for terraforming??? Re: SETI and sea mammals ---------------------------------------------------------------------- Date: 10 Sep 88 23:41:04 GMT From: attcan!utzoo!henry@uunet.uu.net (Henry Spencer) Subject: Re: Chix in Space In article <44600021@pyr1.cs.ucl.ac.uk> william@pyr1.cs.ucl.ac.uk writes: >Forgive me if I am wrong, (it's a while since I studied the theory!!), >but are there portions of the human reproductive system that require >some sense of orientation prior to fertilisation? Something to do with >sperm navigation.... I would think that it has been empirically verified :-) that human fertilization can take place in both vertical and horizontal orientations. More generally, if you contemplate the square-cube law it becomes clear that the smaller things get, the less significant gravity is. Elephants cannot jump or run (although they can *walk* faster than you can run). Humans can. Cats have been known to fall a hundred feet or more unharmed. Mice, especially baby mice, quite happily walk on a ceiling if there's something like a screen that they can get their toes and claws into. (I've seen them do it.) Small insects barely care which way is up. I'd be very surprised if sperm could even *sense* gravity -- on their scale, it is insignificant compared to intermolecular forces. Now, embryo development, that's a different issue. What free-fall babies would look like is most unclear. -- NASA is into artificial | Henry Spencer at U of Toronto Zoology stupidity. - Jerry Pournelle | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 11 Sep 88 08:25:06 GMT From: agate!gsmith%garnet.berkeley.edu@ucbvax.berkeley.edu (Gene W. Smith) Subject: Dinosaur killer impact sites? In article <3391@lanl.gov>, jlg@lanl (Jim Giles) writes: >From article <446@optilink.UUCP>, by cramer@optilink.UUCP (Clayton Cramer): >>> Well, it does appear that a single asteroid hitting Australia wiped >>> out the dinosaurs. >Australia is one of the best preserved old continental land masses in >the world. An impact of the size suggested by Louis Alvarez et. al. >only 65 million years ago would have left a noticable mark. I read recently in the San Jose Mercury News that a large crater in Iowa indicated an asteroidal body hit Iowa about 65 million years ago. -- ucbvax!garnet!gsmith Gene Ward Smith/Garnet Gang/Berkeley CA 94720 "Some people, like Chuq and Matt Wiener, naturally arouse suspicion by behaving in an obnoxious fashion." -- Timothy Maroney, aka Mr. Mellow ------------------------------ Date: 10 Sep 88 23:55:09 GMT From: attcan!utzoo!henry@uunet.uu.net (Henry Spencer) Subject: Re: Possible Disaster Scenarios In article <73@cybaswan.UUCP> iiit-sh@cybaswan.UUCP (Steve Hosgood) writes: >2) What happens if one of the SRBs doesn't light up? I assume the launch > sequencer doesn't blow the bolts, kills the liquid fuelled engines > and attempts to hold the stack on the ground until the one SRB goes > out? ... No, the bolts blow at the same instant as SRB ignition -- there is no delay to see if the SRBs have ignited properly. (I made this mistake once.) Seriously asymmetric SRB performance, with the worst case being ignition failure in one of them, is an unsurvivable accident. >3) What happens if the liquid fuelled engines flame out just after lift-off? > This is probably the least dangerous problem, the 2 SRBs I believe > provide about 5.8 Million Pounds force between them, and the 3 liquids > supply "only" about another million between them. The shuttle may not > get into orbit, but at least it should have a chance of attaining > about 15-20 miles altitude, which ought to be fairly safe... I don't remember for sure, but I think the end result of a failure like this is more-or-less normal flight up to SRB jettison, followed by immediate ET jettison, followed by either an emergency landing or ditching in the ocean. This assumes that there are no major control problems at SRB burnout, given that the liquid engines can't be used to compensate for asymmetric burnout. >[Soviets] I wonder why they jettison the docking >module before tring to fire the retro rockets to commence re-entry? Surely >there would be time enough afterwards? ... Probably they don't want the docking module wandering around uncontrolled nearby during reentry. Also, the less mass is on board at retrofire time, the smaller and lighter the retros can be. -- NASA is into artificial | Henry Spencer at U of Toronto Zoology stupidity. - Jerry Pournelle | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 11 Sep 88 05:44:02 GMT From: silver!chiaravi@iuvax.cs.indiana.edu (Lucius Chiaraviglio) Subject: Re: Chix in Space [About a tongue-in-cheek suggestion for a shuttle experiment funded by Kentucky Fried Chicken, to study chicken development in space -- actually not a bad idea, but I doubt Kentucky Fried Chicken would fund it.] In article <44600021@pyr1.cs.ucl.ac.uk> william@pyr1.cs.ucl.ac.uk writes: [Last part of the suggestion is >>] >> It may also offer clues as to how human embryos may one day >>develop in space. > >Forgive me if I am wrong, (it's a while since I studied the theory!!), >but are there portions of the human reproductive system that require >some sense of orientation prior to fertilisation? Something to do with >sperm navigation. [. . .] I very much doubt it. Remember that mammalian females change position many times between copulation and fertilization, which would really mess up gravity-dependant sperm. Also, mammalian eggs do not have the gravity- sensitive cytoplasmic determinants that amphibian eggs have (or, initially, any cytoplasmic determinants at all, it seems -- the cells formed by the first 3 divisions seem to be for all practical purposes entirely identical, and can be rearranged freely without messing up the subsequent embryo). Note that if mammalian eggs and embryonic development were gravity-dependant, it would be very hard to get them to develop properly, again due to the changing position of mammalian females (yes, vivapary does have its disadvantages). However, bird eggs (as well as reptile eggs) are even larger and yolkier than amphibian eggs, and while it is predicted that the absence of gravity will not disturb amphibian eggs (or reptile or bird eggs) -- that is, it takes gravity in the wrong direction and at the right time to mess up development -- the required data is not yet available. Experiments to test the development of amphibian and fish (similar kind of eggs and development) embryos in space are being designed in the Department of Biology at Indiana University. It is my understanding that rats were taken up on one of the Skylab flights (unless I am getting mixed up and it is the Russians that did this) and allowed to mate and produce offspring. The offspring developed completely normally, and did not even suffer the bone calcium loss that their parents were experiencing. Unfortunately, I don't have the reference for this. Anyone else know of this? -- Lucius Chiaraviglio chiaravi@silver.bacs.indiana.edu lucius@tardis.harvard.edu (in case the first one doesn't work) "NO DYING ALLOWED." -- The Maytag coin-operated washing machine instruction poster. "This would be nice!" -- graffitti seen on the Maytag coin-operated washing machine instruction poster in the Daniels laundry room in Currier House at Harvard University. ------------------------------ Date: 11 Sep 88 14:59:40 GMT From: paul.rutgers.edu!masticol@rutgers.edu (Steve Masticola) Subject: Re: Possible Disaster Scenarios Henry Spencer := >, Steve Hosgood := >> > >[Soviets] I wonder why they jettison the docking > >module before tring to fire the retro rockets to commence re-entry? Surely > >there would be time enough afterwards? ... > Probably they don't want the docking module wandering around uncontrolled > nearby during reentry. Also, the less mass is on board at retrofire time, > the smaller and lighter the retros can be. A third good reason is that if they've started re-entry and something goes wrong with jettisoning the docking module, they'd have very little time to fix the problem. Even if everything went right, they'd still cost themselves time when they had very little to spare. Jettisoning the docking module simplifies things all around. I'd hope they don't throw it so far away that they can't get back to it if something goes wrong with re-entry... - Steve (masticol@paul.rutgers.edu) ------------------------------ Date: 11 Sep 88 21:12:24 GMT From: cfa!cfa250!mcdowell@husc6.harvard.edu (Jonathan McDowell) Subject: Re: Possible Disaster Scenarios From article <73@cybaswan.UUCP>, by iiit-sh@cybaswan.UUCP (Steve Hosgood): > BTW, I was glad to see the Soviets managed to sort out their problem in > returning those Cosmonauts from Mir. I wonder why they jettison the docking > module before tring to fire the retro rockets to commence re-entry? Surely > there would be time enough afterwards? (Followups on this last point to > sci.space please). Yes, they used to do this (Soyuz-1 to Soyuz-40), jettisoning it at the same time as the equipment-aggregate module (the thing with the engine in) a few minutes after retrofire, but starting with the Soyuz T series in 1980 they have jettisoned the orbital module prior to reentry. Why? Well, every kilogram of mass in the orbital module that you accelerate to reentry speed is one kilo less in the descent module that you bring home. There's no point in using your deorbit burn to bring down any more junk than you need... this is just the old staging principle used at launch time. But I wonder if theyre beginning to regret that saved mass; it would be nice to have extra resources if you get stuck like that. - Jonathan McDowell ------------------------------ Date: 11 Sep 88 21:18:49 GMT From: vsi1!daver!mfgfoc!mike@ames.arc.nasa.gov (Mike Thompson) Subject: Re: NASA and McDonnell Douglas sign commercial launch agreement (Forwarded) From article <14551@ames.arc.nasa.gov>, by yee@ames.arc.nasa.gov (Peter E. Yee): > Jim Ball > Headquarters, Washington, D.C. September 7, 1988 > RELEASE: 88-124 > NASA AND McDONNELL DOUGLAS SIGN COMMERCIAL LAUNCH AGREEMENT > > NASA and the McDonnell Douglas Astronautics Company, St. > Louis, announced today the signing of an agreement providing for > the firm's use of facilities at the Kennedy Space Center, Fla., > and technical support from the Goddard Spaceflight Center, > Greenbelt, Md., in support of commercial launches. > All right, lets here it for free enterprise in space. I am beginning to think that the only way to preserve (or restore) the U.S. at the forefront of space technology is to make sure that our industry can make a profit in space. This agreement is something that is 20 years late in coming. I wish the best of luck to McDonnell Douglas and their pioneering efforts in the commercializing of the high frontier. Hopefully the government will now encourage other companies which are high on talent and vision, but low on cash, to provide competition for McDonnell Douglas. I hope that the state of our (the country as a whole) space program is somewhat analagous to where commercial aviation was in the 1920's and 30's where the military benifits of aviation were apparent and the government encouraged private enterprise into development of aviation through air mail. Now if Boeing and Rockwell can get on the ball slowly evolve from defense oriented industry to a space oriented industry. Mike Thompson Disclaimer: These are just my thoughts and in no way reflect the opinion of my company whatever it may be. --------------------------------------------------------------------------- Michael P. Thompson FOCUS Semiconductor Systems, Inc. net: (sun!daver!mfgfoc!engfoc!mike) 570 Maude Court att: (408) 738-0600 ext 370 Sunnyvale, CA 94086 USA --------------------------------------------------------------------------- ------------------------------ Date: 12 Sep 88 01:12:15 GMT From: Portia!doom@labrea.stanford.edu (Joseph Brenner) Subject: Re: Alien civilizations, improved grey goo, and biotech civilizations... C445585@UMCVMB.BITNET ("John Kelsey") writes with essentially three topics: I A planet surviving a beserker attack would begin destroying beserkers. II Beserkers may take the form of "Grey Goo" III Technical civilizations may be unlikey, may destroy themselves, may be uninterested in radio, may be uninterested in expansion etc. Part I seems like a good point to keep in mind, part II is a reasonable observation, but part III falls into what seems to be a perpetual trap for people new to the Fermi Paradox. An explanation for the *complete absence* of observed extra-terrestrial, industrial species has to cover an enourmous number of stars, and must be true for *almost every* potential species. Notions like "Maybe they tend to destroy themselves somehow" just cuts the numbers by another factor of 100 or 1000 or so, and still doesn't reduce the expected result to zero. (I'll try and get references for this reasoning, if you insist. I picked up most of this from a David Brin editorial in Analog, several years ago. Brin comes across as an intelligent guy when he's not writing fiction.) Part I does make a good point: there are presumably competing effects that could be suppressing the beserkers. The trouble is that the reason we started talking about beserkers in the first place is as an explanation for the absence of observed aleins. If there are no beserkers we ought to be seeing non-beserkers. The explanation that Gregory Benford goes for in his novels (ACROSS THE SEA OF SUNS etc.) is that the beserker's *have* wiped out almost everyone, but that long ago the watchdogs in our system were destroyed and have not yet been replaced. This works as a hypothetical explanation of the Fermi paradox, because it postulates a *local* occurence, making *us* a special case, rather than trying to postulate some weird effect that causes *all* intelligent races to self-destruct. (Benford comes across as an intelligent guy even when he is writing fiction.) (BTW, There's an extension to John Kessel's reasoning that I might propose: A planet that's been attacked by beserkers might come to the conclusion that the best defense against future attacks is to release their own version of beserkers...) -- Joe B. (J.JBRENNER@MACBETH.STANFORD.EDU Materials Science Dept/Stanford, CA 9430) cont SRB jluctle ockinu.eduu.eduuExmicopminstparetan) W) W)) DYdoesia!e Ie Iense aC. Ifore roiy dureentrhe tq q q? ? ??well)arel fewittonlyonlyoand pI dhave have htyunderproduget tard a. . .isasle beJohn B.in dein deiiP q q qEDTEDTEOUgencnfe*hib fas fas ormalormalopopoppz-z-zre thEloyoyooring.just descdescdy-entiaentiaeeB B BB!!!Mato wto wt S S f the McDPossPossPand in- Tyrmes.mes.md alen rattralJohn ETHthat tthat ttedorttakth%es ac: periI r21212 syix USUSUe,@laestrestreig-0-lfertyetno mno mntraplateewwhect tion pion pi proed-agoagoa)8@aa 888 8dddd f a+edive-Ai X-re iviKKKivK f a+iidrewi2) +tr(mQQQwn J蹹->adddddddvidryv/smYYYn Yhhhsrhes>+MdsrsmfodddcFrҀ))2K)2Kjehr(++++[IDew ;;;[wr(888ddҀwAddDDDbotD/smddddddd"Ydď+ NAa"sm$)2Kr( ID dfI+ Fr...>o.(((8J999 (99+ɞ@aŹdlIDew rF_КI@ŮX[I'(Aa"smhm889І)2K8, AdaŹɞ)2D D rө[8[I +/8JǚII "s0 S[<<<ܺ CM[w[w[ 8[ se04 9--ArmmA@@cD!"smsI'I'GGG)ArA88888")2K8UUUauecivu+@@褤mp sem !e !e !dsD D ̀)2K)2K퀀)2Ҁhihih, mmmd mżMT++v88888cG444QQQr(Dsay S+"smh"smh Xggg"sm"smsas"----- s)2K"sm)ACddddd[ dsh "sm"smǛhhh khD rFD rF̣2褤褤"smLj"smsas)A4444444a r@r(GGD rFf褡90"sms"sms8J Ҁwhh"s[Lj[ɞ++ٚIgrenc[w[DzDzliDD rF̐d))a$a$9 К)2)2..el a XMppp[<8d)iocDcrs"se el ael aeYf !e !!e !!4 8+m, m{dž--++l..>ff8+!e !!e !!t!D rF̍emooo++v++v+ArA888a)AMTM+++[8/++lY88rdQ///<<<++v+8Ҁo-------Av+ !!nXZcli褡((({888褱 ) e8I Xb//+/+/ŤXZQmmmmmr@ars+m++ǚ JZc222UU 2 GU퀀)kkkIgMI <<-SD rD D F_'aAaŹ⮮dQ/HSbxZS+Rb"-ө]//XZrGsY<4"'KGG̡9-I "smh)+mc n[Lr(GG̡F)@ax[8֤"sm"sm:f"smh)ǚ[Я n9ԛ0-')D ǚif, aeǛD Bfڠ)2Ke'ddd88dsHSi⮅aII F>"smh)"smh)@@2Ommm"smh [--uuu[IauDof loWh dsds ae aeLjh/@:@:@XZrXZrXD rF̐8D rF̐