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/usr1/ota/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl) (->ota+space.digests) ID ; Tue, 12 Sep 89 19:30:42 -0400 (EDT) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Tue, 12 Sep 89 19:30:17 -0400 (EDT) Subject: SPACE Digest V10 #32 SPACE Digest Volume 10 : Issue 32 Today's Topics: JPL address for ordering VOYAGER images. Re: Galileo Mission Re: Economies of Scale in Launchers Voting via taxes and other 3&*%^#! Re: Voyager: Tape recorder? Re: Galileo Jovian atmospheric probe -- is it sterilized??? Pegasus Status - 31 Aug 89 Re: Galileo Jovian atmospheric probe -- is it sterilized??? Re: Message on Mars Re: Galileo Jovian atmospheric probe -- is it sterilized??? Exotic Thrusters Re: Magnum snoopsat Re: Mars "face" image data Re: Neptune on the Boobtube Tracking Military Satellites ---------------------------------------------------------------------- Date: 31 Aug 89 15:22:44 GMT From: wrksys.dec.com!klaes@decwrl.dec.com (CUP/ASG, MLO5-2/G1 6A, 223-3283) Subject: JPL address for ordering VOYAGER images. The following address is for ordering spacecraft images and other reference material from the Jet Propulsion Laboratory: Public Relations - JPL 4800 Oak Grove Drive Pasadena, CA 91109 I hope this will be useful to those of you looking for images of the Neptune system from VOYAGER 2. Larry Klaes klaes@wrksys.dec.com or - ...!decwrl!wrksys.dec.com!klaes or - klaes%wrksys.dec@decwrl.dec.com EJASA Editor, Astronomical Society of the Atlantic N = R*fgfpneflfifaL ------------------------------ Date: 31 Aug 89 18:42:32 GMT From: b.gp.cs.cmu.edu!Ralf.Brown%B.GP.CS.CMU.EDU@pt.cs.cmu.edu Subject: Re: Galileo Mission In article <1050400001@cdp>, christic@cdp.UUCP wrote: >to Jupiter. Galileo will be powered by 50 pounds of plutonium. I keep hearing 47 and 50 POUNDS of plutonium (so far only from opponents of launching the Pu). I can believe that the *RTGs* weigh 50 pounds, but 50 pounds of Pu??? That sounds way off. Does anybody have the real figures on this? ------------------------------ Date: 31 Aug 89 18:18:54 GMT From: terry@astro.as.utexas.edu (Terry Hancock) Subject: Re: Economies of Scale in Launchers In article <131@bambam.UUCP> bpendlet@bambam.UUCP (Bob Pendleton) writes: >From article <310013@hpclove.HP.COM>, by campbelr@hpclove.HP.COM (Bob Campbell): >>> Nope, high molecular weigth exhaust is better in a high pressure >>> environment. That is why there are solid fuel strap ons on so many >>> boosters. In a vacuum you want the lowest possible weight exhaust. >>> >>> Bob P. >> >> Are we confusing high thrust with efficiency? > >Could be. I don't claim to be an expert. > I would like to interject that right after launch, high thrust DOES mean higher efficiency. Just to prove this, ask yourself why Ion drives are useless as launchers. It's simple -- they don't produce enough thrust to even balance their weight in a 1 gee field, much less accelerate anything. Similarly, high thrust engines, which generate high accelerations soon after launch are more efficient than low thrust engines (of the same specific impulse). Consider two launchers, of the same specific impulse, one which accelerates at two gees and another which accelerates at eleven gees. The first one is wasting 1/3 of its fuel to support its weight, the second only 1/12 -- so clearly you can afford to lose some specific impulse in order to gain more thrust and be more efficient. This only holds for straight verticle flight, of course, and only for a short while after launch -- but then, that's what the first stage is for (on a conventional launcher, Pegasus uses slightly different physics, for example). ********************************* Terry Hancock terry@astro.as.utexas.edu ********************************* ------------------------------ Date: 31 Aug 89 14:24:22 GMT From: unmvax!deimos.cis.ksu.edu!cveg!hcx!jws3@ucbvax.Berkeley.EDU (6079 Smith James) Subject: Voting via taxes and other 3&*%^#! In article <8908291631.AA24231@gemini.arc.nasa.gov>, greer%utd201.dnet%utadnx@utspan.span.nasa.gov writes: > >From: eplrx7!leipold@louie.udel.edu (leipold) > >$1. (As a matter of fact, I think allowing people to vote with their > >taxes would be a good idea. Let Congress and the IRS make up forms so > >you can figure how much you owe, but then _you_ decide what percentage > >of what you owe goes to what part of government. But I digress from > >sci.space...) Neat idea. Pretty soon we'd spend 70% of the budget on Social Security, 25% on Welfare, 4% on defense, and maybe .00001% on space. If you let people vote themselves a free lunch, they'll take it. > Another good statistic is that Americans spent $17G on entertainment > last year! People who say space program money would be better spent on > should be asked to forgo movies, TV, music, > all forms of entertainment. Nor, for that matter, should they be allowed > information or activity of any kind which is not conducive to the > furtherance of . Now flip that. "People who say money would be better spent on the space program should be asked to...." Does that sound reasonable to you? No? Didn't think so. The whole point of NASA (originally) was to do things in space that the private sector couldn't justify to The Consumer. That has flipped 180 degrees, but the idea remains. Give a democracy power of taxation and power of budgeting, and it'll destroy itself quickly. Essentially, if we want a space program, we'll have to buy stock in private space companies (NOT milindustrial governmentplace contractors). The uneducated, pap-fed population of this country simply isn't interested in long-range planning beyond their new TV. Elitist ranting from: James Smith JWSMITH@nasamail.nasa.gov ------------------------------ Date: 28 Aug 89 12:22:57 GMT From: b.gp.cs.cmu.edu!Ralf.Brown%B.GP.CS.CMU.EDU@pt.cs.cmu.edu Subject: Re: Voyager: Tape recorder? In article <4259@utastro.UUCP>, terry@utastro.UUCP (Terry Hancock) wrote: > This is what happens when it takes 10 or 20 years for a >spacecraft to get to its destination -- it's obsolete by the time >it arrives! With current launch schedules, it's obsolete by the time it's launched.... :-( -- UUCP: {ucbvax,harvard}!cs.cmu.edu!ralf -=-=-=-=- Voice: (412) 268-3053 (school) ARPA: ralf@cs.cmu.edu BIT: ralf%cs.cmu.edu@CMUCCVMA FIDO: Ralf Brown 1:129/46 FAX: available on request Disclaimer? I claimed something? "For numerical analysis, there are theorems that are true, and theorems that are *really* true." -- John Dennis (in Upson's Familiar Quotations) ------------------------------ Date: 31 Aug 89 18:46:41 GMT From: binkley@boulder.colorado.edu (Jon Binkley) Subject: Re: Galileo Jovian atmospheric probe -- is it sterilized??? In article <1989Aug31.131156.27666@jarvis.csri.toronto.edu> wayne@csri.toronto.edu (Wayne Hayes) writes: >I remember hearing a ruckus awhile ago regarding the sterilization of the >the Galileo spacecraft's probe into Jupiter's atmosphere. Aparently they >were out of funds to sterilize it. Is this still true? As far as I know (not very), yes. >In the remote >possibility that Jupiter's atmosphere harbors indigenous life, we may >pollute the atmosphere with Earth's life and never know for sure whether >the life we later discover is in fact indigenous. Actually we could tell with pretty high certainty whether or not life we found there came from here; even in the unlikely event that the putative alien used nucleic acids, those nucleic acids would stick out like sore thumbs when compared at the sequence leval to terrestrial DNA and RNA. (Unless, of course, both Earth and Jupiter were originally seeded from the same group of extraterrestrials, using unsterilized probes! :-) If I was going to worry about anything (and I'm not), I'd worry more about the terrestrial bacteria out-competing the natives. >Thoughts? I think that, while it would have been nice to sterilize the probe, the importance of the mission far overshadows the minute chance of inadvertantly colonizing Jupiter. -Jon ------------------------------ Date: 31 Aug 89 22:39:15 GMT From: skipper!shafer@ames.arc.nasa.gov (Mary Shafer) Subject: Pegasus Status - 31 Aug 89 Just like the subject line says, it's time for a Pegasus status update. The Pegasus is not attached directly to the B-52; rather, it's attached to its own pylon which is attached to the B-52. Using this intermediate pylon means that the B-52 doesn't have to be modified for each vehicle to be carried. The Pegasus pylon was mated to the Dryden B-52 late last week. Early this week (Tuesday, I think) the Pegasus vehicle was mated to the pylon. I understand that this first mating went very well. Today the B-52, with the Pegasus, went down to the Weight & Balance Hangar, for weighing and center of gravity (cg) determination. The latest word is that the project team is moving down the timeline quite well and launch is still planned for October. I'm not involved with this project, except as an interested bystander, so this status mostly concerns progress visible as I walked by the B-52. I haven't followed the scheduling very closely--when was the first launch originally scheduled? -- -- Mary Shafer shafer@elxsi.dfrf.nasa.gov arpa!elxsi.dfrf.nasa.gov!shafer NASA Ames-Dryden Flight Research Facility, Edwards, CA Of course I don't speak for NASA ------------------------------ Date: 31 Aug 89 20:52:51 GMT From: rochester!dietz@pt.cs.cmu.edu (Paul Dietz) Subject: Re: Galileo Jovian atmospheric probe -- is it sterilized??? In article <1989Aug31.131156.27666@jarvis.csri.toronto.edu> wayne@csri.toronto.edu (Wayne Hayes) writes: >I remember hearing a ruckus awhile ago regarding the sterilization of the >the Galileo spacecraft's probe into Jupiter's atmosphere. Aparently they >were out of funds to sterilize it. Is this still true? > >.. The fact that Jupiter >may be too hostile for Earth bacteria to survive, or that there may be >no life there, are simply risks I consider *much* too large. > >Thoughts? I was under the impression that the general opinion is that life as we know it could not survive on Jupiter, because downdrafts would carry any life too deep into the atmosphere in a matter of days. At high temperature, the reaction of hydrogen with organic matter to form methane, water and ammonia is rapid and exothermic. Similarly, life on Jupiter is thought to be unlikely, because complex prebiotic molecules could not accumulate. The technophobes might worry, but I'm not going to. Paul F. Dietz dietz@cs.rochester.edu ------------------------------ Date: 29 Aug 89 16:25:16 GMT From: ssc-vax!shuksan!tahoma!jpg3196@beaver.cs.washington.edu (James P. Galasyn) Subject: Re: Message on Mars In article <1989Aug27.015908.1834@utzoo.uucp>, henry@utzoo.uucp (Henry Spencer) writes: > Uh, this proves that the *model* looks artificial as hell regardless of > angles, and that the *model* is quite symmetrical. It does not prove > that this is the only model which fits the Viking photographs, or that > the model corresponds to the Martian surface feature in question. Quite so. Keep me honest. Jim "Death" Galasyn ..!uunet!bcstec!tahoma!jpg3196 ..!uw-beaver!ssc-vax!shuksan!tahoma!jpg3196 ------------------------------ Date: 1 Sep 89 01:41:09 GMT From: rochester!dietz@rutgers.edu (Paul Dietz) Subject: Re: Galileo Jovian atmospheric probe -- is it sterilized??? In article <34482@apple.Apple.COM> stadler@Apple.COM (Andy Stadler) writes: >In article <1989Aug31.205251.4711@cs.rochester.edu> dietz@cs.rochester.edu.UUCP (Paul Dietz) writes: >> >> [..regarding sterilization of Galileo to protect Jovian life..] >> >>The technophobes might worry, but I'm not going to. >Why must concern for life and environment == technophobe? I program computers >for a living, like to play with high-tech "toys", and support a strong >program of space exploration; yet the thought of accidentally contaminating >or even killing other yet unknown life forms scares and concerns me. It's a question of perceived risk. It is believed that the risk is very small. If one asks that the risk be zero, then one is a technophobe -- and, IMHO, a fool. Paul F. Dietz dietz@cs.rochester.edu ------------------------------ Date: 1 Sep 89 05:07:20 GMT From: ogccse!blake!wiml@husc6.harvard.edu (William Lewis) Subject: Exotic Thrusters In some article, dietz@cs.rochester.edu (Paul Dietz) mentioned MPDs, Magnetoplasmadynamic thrusters. (That's a mouthful...) I too would like more information on these. I've heard that some have been tested, and had quite high thrust &c., but a very short lifespan: the components corroded or something. Sorry I don't have any references on this. Might someone else (specifically, Paul Dietz of `cs.rochester.edu'?) --- phelliax "I'm not a real message. I just play one on Usenet." ------------------------------ Date: 31 Aug 89 22:57:37 GMT From: sco!staceyc@uunet.uu.net (Stacey Campbell) Subject: Re: Magnum snoopsat In article <11757@cit-vax.Caltech.Edu> palmer@tybalt.caltech.edu.UUCP (David Palmer) writes: > 2) Geosynchronous orbit (presumably at the longitude of Moscow) > 3) Sends data to the spy nest at Pine Gap, Australia. A satellite in geosynchronous orbit over the European part of the Soviet Union would be most unlikely to transmit to Pine Gap; which would probably be the most remote station. Are reconnaissance satellites ever placed in geosynchronous orbit? -- Stacey Campbell - uunet!sco!staceyc - The Santa Cruz Operation ------------------------------ Date: 1 Sep 89 00:58:43 GMT From: cs.utexas.edu!ut-emx!hutto!henry@tut.cis.ohio-state.edu (Henry Melton) Subject: Re: Mars "face" image data That was fun, although I had to figure out how to put the data into a MAC format. Now that I have something to work with, it is interesting to play with. The raw data looks like junk .. but after you rotate it, despeckle it, invert it, play with the contrast, and stare at it for a while, it _does_ look like a face. Now if I can only get the rest of the planet to play with .... -- Henry Melton ...!cs.utexas.edu!ut-emx!hutto!henry 1-512-8463241 Rt.1 Box 274E Hutto,TX 78634 ------------------------------ Date: Fri, 1 Sep 89 09:58:55 PDT From: Peter Scott Subject: Re: Neptune on the Boobtube asuvax!mcdphx!mcdchg!ddsw1!corpane!sparks@handies.ucar.edu (John Sparks) writes: >At one point a caller asked what will happen to Voyager, where will it go when >it leaves the system. >The answer was that in 8,000 years it will fly by Barnard's Star, in 20,000 or >so it will pass Proxima Centauri, and then the Oort cloud. I dunno about the Oort cloud, but the figures look right for Barnard's Star and Proxima Centauri. Remember that in these cases "closest approach" is still several light years, and if you visualize the path, dropping perpendiculars onto it from the stars... you get the picture. Peter Scott (pjs@grouch.jpl.nasa.gov) ------------------------------ Date: 1 Sep 89 15:01:03 GMT From: cdp!jstone@labrea.stanford.edu Subject: Tracking Military Satellites Tracking Military Satellites I would be very interested in learning of anyone tracking low altitude American Military satellites - those for which the Godda rd Satellite Situation Report lists "Current Elements Not Maintained." In particular, I am interested in obtaining orbital infor mation on 1988-99A, launched from Vandenberg on 6 November 1988. I am also wondering whether there is a BBS for people who track such satellites, or which BBS's are likely to be a focus for such people. ------------------------------ End of SPACE Digest V10 #32 *******************