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 ; Sat, 9 Jun 1990 01:56:55 -0400 (EDT) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sat, 9 Jun 1990 01:56:26 -0400 (EDT) Subject: SPACE Digest V11 #511 SPACE Digest Volume 11 : Issue 511 Today's Topics: Janes Spacecraft/Satellites wanted! Hubble Space Telescope Update - 06/08/90 Re: Tides Re: HAWAII/ROCKET very long - 61k Re: Tides Re: Ulysses risks II: PuO2 dangers Re: Missing mass Re: Plutonium Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription notices, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: 8 Jun 90 12:19:33 GMT From: fernwood!portal!cup.portal.com!Lee_-_Reynolds@decwrl.dec.com Subject: Janes Spacecraft/Satellites wanted! Hi. Would any kind soul/librarian out there have a non-current copy of Janes SPacecraft/Satellites that they'd be willing to part with for a nominal fee? (I'm doing a little tracking and I need a lot of info that Janes seems to be the only one-stop provider of....) Thanks, Lee ------------------------------ Date: 8 Jun 90 16:26:14 GMT From: sdd.hp.com!elroy.jpl.nasa.gov!jpl-devvax!jato!mars.jpl.nasa.gov!baalke@ucsd.edu (Ron Baalke) Subject: Hubble Space Telescope Update - 06/08/90 Hubble Space Telescope Update June 8, 1990 All of the Hubble Space Telescope's instruments were reported to be in good order, with no problems. The Faint Object Spectrograph (FOS) reports a pressure of 7e-6 torr and engineering reports that the satellite is 9.9 degrees off optimum power angle. The Faint Object Camera (FOC) has taken 125 internal images. Two Wide Field Planetary Camera (WFPC) pictures were taken last night The field was in Carina, just as the pictures were from June 3 and June 4. A 10s and a 100s second exposure was taken. The field was supposed to have been shifted slightly from the June 3 location to bring our one bright star into the center of PC5, but no slew was put into the system; consequently the star locations are nearly identical to that of the June 3 exposures (the stars moved by about 9 pixels). An additional picture will be taken on Sunday. Currently, Part 3 of Bootstraph Phase B is in effect. If this goes successfully, there will be a secondary mirror movement before the next picture. It was discovered that a guide star pair for the WFPC supporting images may have failed due to a confusing field. A new guide star pair was chosen. A software problem may exist in the Fixed Head Star Tracker (FHST) in the choice of the reduced field of view (~1 x 1 deg) found within the 8x8 deg window. In addition, there are problems with near neighbors and threshold levels. In a test yesterday, it was found that 15 out of 60 updates failed due to confusion with a neighbor star. Another FHST concern is possible orbital position dependent noise. Scattered light was suggested as a possibility for this and a 24 hour test of the FHST was proposed where they would map the noise as a function of orbital position. The star catalogue used by the FHSTs still remains a concern. The FHSTs on the telescope needs one star, assuming no neighbors, for its positional verification. The SMM satellite was found to use three stars, checked with on-board software. _ _____ _ | | | __ \ | | Ron Baalke | baalke@mars.jpl.nasa.gov | | | |__) | | | Jet Propulsion Lab | baalke@jems.jpl.nasa.gov ___| | | ___/ | |___ M/S 301-355 | |_____/ |_| |_____| Pasadena, CA 91109 | ------------------------------ Date: 8 Jun 90 17:37:19 GMT From: usc!elroy.jpl.nasa.gov!aristotle!pjs@ucsd.edu (Peter Scott) Subject: Re: Tides In article <1990Jun8.163052.19763@oracle.com>, fmcwilli@oracle.oracle.com (Floyd McWilliams) writes: > Therefore, the Sun's gravitational pull on the Earth is 177 times > that of the Moon (divide mass ration by square of distance ratio). > > This is what we would expect -- we revolve around the Sun every > year, not the Moon. But it seems to me that tides caused by the Sun > should be 177 times stronger than those caused by the Moon! What's wrong > with my reasoning? Tides aren't caused by absolute gravitational attraction, but by the differential attaction on opposite sides of the earth. Imagine an inverse-square graph; tides are stronger the steeper the slope. What happens to the slope when you get further out? This is news. This is your | Peter Scott, NASA/JPL/Caltech brain on news. Any questions? | (pjs@aristotle.jpl.nasa.gov) ------------------------------ Date: 8 Jun 90 16:29:20 GMT From: idacrd!mac@princeton.edu (Robert McGwier) Subject: Re: HAWAII/ROCKET very long - 61k From article <1050400021@cdp>, by jhanson@cdp.UUCP: > > The reason for posting this message here is that there are many > scientists who are unaware of the enormous environmental > scientist will start thinking of our planet as a complete system > instead of a bunch of discrete parts. I found your submission long and useless. Give me some scientific citations so that I might read them for myself and hopefully these will be free of your emotional arguments. If you wish to foist an idea upon scientists, do it with scientific data if you wish them to consider it as scientists. Bob -- ____________________________________________________________________________ My opinions are my own no matter | Robert W. McGwier, N4HY who I work for! ;-) | CCR, AMSAT, etc. ---------------------------------------------------------------------------- ------------------------------ Date: 8 Jun 90 22:26:37 GMT From: usc!cs.utexas.edu!news-server.csri.toronto.edu!helios.physics.utoronto.ca!physics.utoronto.ca!neufeld@ucsd.edu (Christopher Neufeld) Subject: Re: Tides In article <1990Jun8.163052.19763@oracle.com> fmcwilli@oracle.com (Floyd McWilliams) writes: > > The Sun has 27,000,000 times the Moon's mass (the Sun is 333,000 >times more massive than the Earth, which has 81 times the Moon's mass). > > The Sun is 391 times more distant than the Moon (93,000,000 / >238,000). > > Therefore, the Sun's gravitational pull on the Earth is 177 times >that of the Moon (divide mass ration by square of distance ratio). > > This is what we would expect -- we revolve around the Sun every >year, not the Moon. But it seems to me that tides caused by the Sun >should be 177 times stronger than those caused by the Moon! What's wrong >with my reasoning? > Tides are proportional to the inverse cube of the distance, as they are related to the spatial derivative of the force. By your numbers this makes the lunar tides roughly twice the size of the solar tides. > Floyd McWilliams -- fmcwilli@oracle.com -- Christopher Neufeld....Just a graduate student | He's the kind of person neufeld@helios.physics.utoronto.ca | who'd follow you into a cneufeld@pro-generic.cts.com Ad astra! | revolving door and come "Don't edit reality for the sake of simplicity" | out first. ------------------------------ Date: 8 Jun 90 14:17:43 GMT From: att!tsdiag!davet@ucbvax.Berkeley.EDU (Dave Tiller N2KAU) Subject: Re: Ulysses risks II: PuO2 dangers In article HIGGINS@FNAL.BITNET (William Higgins) writes: >This continues the discussion of the Ulysses probe, its radiothermal >generators, and their risks. Where can I get one???? Seriously, as I proposed in a previous article, this would be an _excellent_ source of heat/hot water for households instead of nasty petroleum-based sources. I'd be willing to drop one into my hot water heater! Since it'd be easier and more efficient on earth to harness the heat generated and convert it to electricity, it might even supply a small household's power needs, too. Any conjecture on the feasiblity of this? What are some of the higher power density fuels available? Inquirin' minds gots'ta know! -- David E. Tiller davet@tsdiag.ccur.com | Concurrent Computer Corp. FAX: 201-870-5952 Ph: (201) 870-4119 (w) | 2 Crescent Place, M/S 117 UUCP: ucbvax!rutgers!petsd!tsdiag!davet | Oceanport NJ, 07757 ICBM: 40 16' 52" N 73 59' 00" W | N2KAU @ NN2Z ------------------------------ Date: 8 Jun 90 23:18:58 GMT From: uoft02.utoledo.edu!fax0112@tut.cis.ohio-state.edu Subject: Re: Missing mass > In article FORTMENU@tudsv1.tudelft.NL ("Nick A. van Goor") writes: >> >>The mising matter all exists of disappeared socks..... >> > You can tell its a slow day... How about an opposing theory a friend I came up with years ago (personally I think this other one smells! Someone had to say it, darn it.) The reasoning was like this: -Most of the matter in the universe is hydrogen -Therefore most of the missing mass is hydrogen -Where did it go? -Where all things like pens, socks and bic lighters all go to when missing -Since most of the universe is dark, it is dark there too -When somone finds this place their first reaction will to "flick their bic" -Is this where the big bang came from? A case of spherical reasoning! Robert Dempsey Ritter Obs. "The greater the mind the greater the need for play" - Einstein? ------------------------------ Date: 9 Jun 90 00:15:00 GMT From: zaphod.mps.ohio-state.edu!samsung!crackers!cpoint!frog!john@tut.cis.ohio-state.edu (John Woods) Subject: Re: Plutonium In article <14477@thorin.cs.unc.edu>, leech@homer.cs.unc.edu (Jonathan Leech) writes: > In article <900605082239.21000116@AGCB7.LARC.NASA.GOV> KLUDGE@AGCB7.LARC.NASA.GOV writes: > >Since Feynman speaks about placing his hands on a warm globe of > >plutonium, and he lived for a good forty years afterward, I can point out > >a few excellent examples of how little damage the radiation does. > Since Feynman died of cancer, perhaps this is not such a great > example. Followups to sci.med. Feynman died of lung cancer. He was a heavy smoker. The conclusion is left to the student as an exercise. -- John Woods, Charles River Data Systems, Framingham MA, (508) 626-1101 ...!decvax!frog!john, john@frog.UUCP, ...!mit-eddie!jfw, jfw@eddie.mit.edu ------------------------------ End of SPACE Digest V11 #511 *******************