Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from holmes.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 ; Tue, 16 May 89 03:18:00 -0400 (EDT) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Tue, 16 May 89 03:17:52 -0400 (EDT) Subject: SPACE Digest V9 #438 SPACE Digest Volume 9 : Issue 438 Today's Topics: Re: asteroid almost hits earth Re: Private funding of space science Re: UFOs and other weird stuff on this list. Asteroids and Dinosaurs (was Re: asteroid almost hits earth) Re: New Orbiter Name Announced Re: memes Re: Near miss Re: space news from March 27 AW&ST Re: asteroid almost hits earth Re: NSS Hotline Update Re: In-flight liquification of air Re: Does anyone know *why* the USAF did this? ---------------------------------------------------------------------- Date: 12 May 89 09:08:30 GMT From: mcvax!ukc!warwick!nfs4!kgd@uunet.uu.net (Keith Dancey) Subject: Re: asteroid almost hits earth In article <103026@sun.Eng.Sun.COM> mae@sun.UUCP (Mike Ekberg, Sun {GPD-LEGO}) writes: > >But even greater menace lurks in the darkness of space. Scientists have >speculated that objects as large as several miles across have crashed into the >Earth, spewing millions of tons of debris into the atmosphere, blotting out the >Sun for months or years, and causing mass extinctions of life -- including, >many believe, the dinosaurs. Of the known larger Earth-crossers, none seem to >pose a threat in the near future. But, says Shoemaker, "until we have tracked >all of them, something could sneak up on us." > My understanding is that the demise of the dinosaurs extended over a period of order of magnitude of a thousand years. Certainly long enough to place doubt upon the viability of a single catastrophy such as the one mentioned. If the palaeontological evidence is not contradicted (and I have understood it correctly) then a *series* of such catastrophic strikes would be required. That is not say a single catastrophy is ruled out, but it looks as though its effects must be longer-lived than a few years. As for tracking "all" large, earth-crossing asteriods, there is a danger of conveying the unspoken idea that the number may be fixed and finite for all time. I think such a concept is also under question. There is just the possibility that these bodies are disturbed out of an otherwise harmless state by the dynamics of the galaxy. This means their numbers may be added to at any time unexpectedly. -- Keith Dancey, UUCP: ..!mcvax!ukc!rlinf!kgd Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, England OX11 0QX Tel: (0235) 21900 ext 6756 JANET: K.DANCEY@uk.ac.rl.inf ------------------------------ Date: 13 May 89 09:28:40 GMT From: unmvax!polyslo!jmckerna@ucbvax.Berkeley.EDU (Dr. Dereference) Subject: Re: Private funding of space science In article <8905120536.AA01379@crash.cts.com> mordor!rutgers!pnet01.cts.com!jim@angband.s1.gov writes: >The government is the best source of support for research NOT development [a whole lot deleted] This idea is ok as a general principal but there are many exceptions. The rest of the posting had some reasonable ideas but was very ideological and simplified complex situations which have many exceptions. In order to do a lot of R&D hardware needs to be developed (ie if you want to explore the planets, you have to develop space probes). While the governemnt certainly should not do the development itself, it still needs to fund the development of hardware for R&D that will not be done privately. As for government involvment in operations, the best people to operate the hardware built for R&D are usually the scientists doing the R&D, who are usually government employees (ie JPL). I agree that NASA should stop developing and operating launch services itself and should buy such services from private companies. John L. McKernan. Student, Computer Science, Cal Poly S.L.O. ------------------------------------------------------------------------------- The future is rude and pushy. It won't wait for us to solve today's problems before it butts in with tomorrow's. ------------------------------ Date: 12 May 89 18:35:22 GMT From: portal!cup.portal.com!hkhenson@uunet.uu.net (H Keith Henson) Subject: Re: UFOs and other weird stuff on this list. derek@hsi.UUCP (Derek Lee-Wo) posts: ---------- Sometimes I wish I were born a few hundreds years in the future. Could one just imagine what it would be like to hop a space shuttle to another planet as easily as we could now jump on a plane to London. Now if only I could believe in re-incarnation :-) ---------- If you have a background in physics, chemistry, or biology or even computers, you might look into the emergence of nanotechnology from these disciplines. Try reading _Engines of Creation_ by Eric Drexler, and if you buy it, consider cryonics as a way to get you into the future. Info from the non-profit Alcor Life Extension Foundation can be obtained by writing them at 12327 Doherty St. Riverside, CA 92503 or call 800-367-2228 (714-736-1703 in California) Keith Henson ------------------------------ Date: 13 May 89 13:03:55 GMT From: castor.ucdavis.edu!ccs013@ucdavis.ucdavis.edu (Jason) Subject: Asteroids and Dinosaurs (was Re: asteroid almost hits earth) In article <6101@nfs4.rl.ac.uk> kgd@inf.rl.ac.uk (Keith Dancey) writes: >>Sun for months or years, and causing mass extinctions of life -- including, >>many believe, the dinosaurs. >My understanding is that the demise of the dinosaurs extended over a period >of order of magnitude of a thousand years. ...etc.... Please correct me if I am wrong, but is this one of the theories (proofs) behind the "asteroid theory" of the extinction of the dinosaurs ?: Layers of Iridium were found deep into the earth's crust ( i.e. in the layers of the Grand Canyon). Now, being that Iridium is rare on earth but found to be relatively more bountiful in asteroids and meteors, it is suggested that the layer of this element was put on our planet by an extremely large (or as previously mentioned a few extremely large) asteroid(s) which hit earth and caused the clouds of dust ...etc., which eventually killed off the dinosaurs. This dust, if the theory is accurate, was filled with Iridium and when settled created a solid layer over years of rain, erosion ...etc... Is this a widely accepted view? What are the opposing ideas? ___ ___ __ ___ )___ __________________________________ ( | '__| (__ / / / / | II Corinthians 10:17 | \ | (__)\ __) /__/ / / +--------------------------------+ \_| Internet: jygabler@ucdavis |"Why me?!", Garion said. "Do we | | BITNET: jygabler@ucdavis | we have to go thru that again",| | UUCP: ucdavis!jygabler | the dry voice retorted. | ------------------------------ Date: 13 May 89 00:32:26 GMT From: portal!cup.portal.com!mmm@uunet.uu.net (Mark Robert Thorson) Subject: Re: New Orbiter Name Announced I recall that someone suggested that name on Usenet, shortly after the Challenger explosion. ------------------------------ Date: 12 May 89 19:02:53 GMT From: portal!cup.portal.com!hkhenson@uunet.uu.net (H Keith Henson) Subject: Re: memes John Roberts (roberts@cmr.icst.nbs.gov) ends a rather thoughful post with: >My question is not whether the concept of memes can be used to form a >model of the spread and application of ideas, but whether such a model >would be of any actual use, for predicting future events or for some >other application, which it can handle better than conventional methods. "Conventional methods" is a term which I do not understand, but as to predicting future events, I have argued that the mutation/communication complexity of the memetic ecosystem is subject to chaos, that is long term projections are *impossible* for the same reason weather is. Short term projections, on the order of the popularity of a song or book can be made (and are by conventional guesses). As to the use of memetics, I think its most useful application might be to teach people to be more thoughtful about which ideas they accept into their minds. (A 30k byte article "Memes, Meta-Memes, and Politics" is available by email.) Keith Henson (hkhenson@cup.portal.com) ------------------------------ Date: 8 May 89 09:01:49 GMT From: mcvax!ukc!reading!cf-cm!cybaswan!iiit-sh@uunet.uu.net (Steve Hosgood) Subject: Re: Near miss In article <610059087.amon@H.GP.CS.CMU.EDU> Dale.Amon@H.GP.CS.CMU.EDU writes: >> atmosphere (over Colorado, I believe.) I forget how big it was, but it >> stayed in the atmosphere for a few minutes, and it didn't burn up. It >> just kept going back out into solar orbit. > >There is a color picture in a back issue of National Geographic. IT was >a feature article on meteors and such. Within the last 5 years I >believe. > A thousand people will probably say this same thing, but here's my version: The Geographic article is in the September '86 Issue, entitled "Meteorites: Invaders from Space", pages 390-418. The photo mentioned above is on pages 416- 417. Very spectacular it is too. Looking at it reminds me of a similar sort of picture that was (I think) taken from a ship off Italy or Greece in about 1944. Similar bright spot with a tail behind it, though the caption was more along the lines of "UFO sighted over occupied Europe".... Does anyone remember this one? I don't have any Geographics back that far, and anyway, I think it was a newspaper photo. Steve ------------------------------ Date: 13 May 89 00:59:46 GMT From: att!oucsace!oucs!wright!cs7010d@ucbvax.Berkeley.EDU (Student of Dr. Shock) Subject: Re: space news from March 27 AW&ST in article <52000@philabs.Philips.Com>, rfc@briar.philips.com (Robert Casey;6282;3.57;$0201) says: > Xref: wright sci.space:9941 sci.space.shuttle:3068 > Posted: Wed May 10 11:18:38 1989 > > I believe I once heard that Enterprise was damaged (bent frame? or something) > and was not flightworthy. Any truth to this? The Enterprise was never spaceworthy, just a full scale test bed for reentry/flight dynamics. (Unless you mean not even able to do this, anymore) ------------------------------ Date: 14 May 89 00:21:08 GMT From: eugene@eos.arc.nasa.gov (Eugene Miya) Subject: Re: asteroid almost hits earth If you are really interested in this. I recommend the work and writings of Preston Cloud. Longish signature follows "Type 'n' now" Another gross generalization from --eugene miya, NASA Ames Research Center, eugene@aurora.arc.nasa.gov resident cynic at the Rock of Ages Home for Retired Hackers: "You trust the `reply' command with all those different mailers out there?" "If my mail does not reach you, please accept my apology." {ncar,decwrl,hplabs,uunet}!ames!eugene Live free or die. ------------------------------ Date: 13 May 89 15:31:33 GMT From: bfmny0!tneff@uunet.uu.net (Tom Neff) Subject: Re: NSS Hotline Update In article <246900024@cdp> jordankatz@cdp.UUCP writes: > >This is the National Space Society's Space Hotline Update: >Tuesday May 9, 1989. [ a consistent waste of net bandwidth given the existing contributions of Peter Yee, Henry Spencer and (my fave) Jonathan McDowell, however since it keeps the NSS acronym in front of peoples' eyes, I suspect we are stuck with it, sloganeering and all; so, Rolaids in hand, one reads on... ] > The overall flight of the >Shuttle Atlantis has gone fairly smooth, with the exception of a >broken fax machine, and a failed computer. The crew wanted to fix >the fax machine themselves but were ordered not to by ground >control. Not as trivial a problem as it sounds. One of the few things they had room to test given the Magellan weight constraints was a new Text/Graphics System (TGS was the acronym I saw, if it's different someone mail me) for uplinking charts and such. Can someone post details on the failure mode? This could mean delays before it's operational. [ that's one annoyance about these NSS screeds, they appear to be written down to the shoe clerk level. Mustn't let annoying details interfere with the phone tree! ] -- Tom Neff UUCP: ...!uunet!bfmny0!tneff "Truisms aren't everything." Internet: tneff@bfmny0.UU.NET ------------------------------ Date: 13 May 89 08:38:34 GMT From: unmvax!polyslo!jmckerna@ucbvax.Berkeley.EDU (John McKernan) Subject: Re: In-flight liquification of air In article <3961@silver.bacs.indiana.edu> chiaravi@silver.UUCP (Lucius Chiaraviglio) writes: > How is liquification of air to be done without the use of horrendously >heavy equipment and huge energy expenditure? (It seems that both would be >needed to liquify air, especially at the rate that would be needed.) > Also, since air is only 21% oxygen, storage of liquified air would be >quite wasteful of weight and space. Air liquification is an approach the Japanese are taking in their aerospace plane project. The whole point of such a plane is to drastically increase performance over a rocket engine by using the oxygen in the air instead of carrying all your oxydizer with you. So no, the plane would not carry liquified air. The plane uses liquid hydrogen (its fuel) to liquify the air. This is necessary because the engine operates at too high a pressure to practically pump enough normal air into it. The US aerospace plane project (NASP) is trying to build a scramjet which uses carefully shaped scoops to bring air into the combustion chamber without liquifying it. This requires speeds of around 2000 mph before the engine will operate properly (fuel is liquid hydrogen), so another engine/rocket must bring the plane up to that speed. The scramjet is supposed to propel the plane all the way to orbital velocity (17,500 mph). One major problem is that the hottest parts of the scramjet would be over 5000F (!), and the highest temperature jet engine parts currently built can only withstand 2800F. I've read that this project is currently using over a third of all the supercomputer time in the US. It comes as no surprise that the military is interested in a jet with a top speed of 17500 mph, so the project is funded by the military at 300 million a year. The Germans have a somewhat different concept, though I don't know if it's actually funded at this point. They use an airplane to carry a shuttle to 19 miles and 4500 mph, and then the shuttle separates and uses rockets for the additional 13000 mph and 80 miles of altitude. This has the advantage of requiring only current technology. Still, it doesn't seem very cost effective to build a plane capable of carrying a shuttle to 19 miles and 4500 mph (not an easy plane to build) and then still have 80 miles and 13000 mph to go. Note: This information is from an artical in the LA Times 5/8/89. John L. McKernan. Student, Computer Science, Cal Poly S.L.O. ------------------------------------------------------------------------------- The future is rude and pushy. It won't wait for us to solve today's problems before it butts in with tomorrow's. ------------------------------ Date: 13 May 89 15:43:42 GMT From: portal!cup.portal.com!mmm@uunet.uu.net (Mark Robert Thorson) Subject: Re: Does anyone know *why* the USAF did this? I remember seeing a report in the Science and the Citizen column in Scientific American about a year ago, which said that a paint flake 0.2 mm long had impacted a window on one of the space shuttles. It left a crater about 1 cm in diameter. Imagine the effect of hitting a clump of copper wires! Perhaps the proper successor to smart rocks and brilliant peebles will be "genius dust". These could be naked IC's powered by the sun and propelled by tiny ion engines. ------------------------------ End of SPACE Digest V9 #438 *******************