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 ; Thu, 15 Nov 1990 01:32:12 -0500 (EST) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Thu, 15 Nov 1990 01:31:37 -0500 (EST) Subject: SPACE Digest V12 #551 SPACE Digest Volume 12 : Issue 551 Today's Topics: Re: The great light bulb debate Re: Nameplates on space probes Magellan Update - 11/12/90 Re: Creationists and Moon Dust Re: Call for new news group : sci.space.seds LLNL size and Fred micrograv environment (was LLNL astronaut delivery) angular momentum Re: You Can't Expect a Space Station to be Cheap Galileo Update - 11/12/90 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 ---------------------------------------------------------------------- Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 11 Nov 90 22:08:38 GMT From: rti!dg-rtp!bigben!bigben!philip@mcnc.org (Philip Gladstone) Organization: Data General, Development Lab Europe Subject: Re: The great light bulb debate References: <9011092213.AA05755@cmr.ncsl.nist.gov> Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu In article <9011092213.AA05755@cmr.ncsl.nist.gov> roberts@CMR.NCSL.NIST.GOV (John Roberts) writes: >Modern light bulbs are filled with argon, not vacuum. (Expensive ones >use krypton.) As you imply, the old bulbs were evacuated. I believe the main reason for the switchover to inert gas was to reduce the rate of evaporation of the filament at a given temperature. In the UK (10 years ago) light bulbs contained *some* gas to about 30% atmospheric pressure. This is easy to demonstrate by following this procedure: 1) Find a light bulb -- preferably a dead one (it'll be useless if you complete the rest of these instructions). 2) Fill a bucket with water. 3) Find a compass (the drawing instrument) or other sharp spiky object. 4) Use the compass to make a small hole in the metal cap of the bulb. 5) Hold the bulb under water and push the compass into the metal cap and wiggle it around inside. If you do this just right, you will break the glass seal that was used to evacuate the bulb. 6) The water now rushes in to equalise the pressure. You can now judge what the pressure was before you broke the seal by how much water entered. WARNING: If you do this wrong you could break the envelope. For this reason wear gloves. -- Philip Gladstone Development Lab Europe Data General, Cambridge England. +44 223-67600 ------------------------------ Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 11 Nov 90 20:12:26 GMT From: umich!umeecs!msi.umn.edu!cs.umn.edu!kksys!wd0gol!newave!john@CS.YALE.EDU (John A. Weeks III) Organization: NeWave Communications Ltd, Eden Prairie, MN Subject: Re: Nameplates on space probes References: <112263@philabs.Philips.Com>, <68212@bu.edu.bu.edu>, <1990Nov9.014107.10312@nmt.edu> Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu In article <1990Nov9.014107.10312@nmt.edu> dbriggs@nrao.edu (Daniel Briggs): > In article <68212@bu.edu.bu.edu> sultan@bu-ast.bu.edu (Peter Sultan): > > There have been several `nameplates' on US space probes. > C'mon, Peter, the moon is right next door! We may well never see the > Voyagers again I would be surprised to see a Voyager in the Smithsonian in 50 years, but 100 years might not be unreasonable. If us earthlings pooled our expertise and money, as we might someday do, travel within the solar system will be within reach. A Voyager might be scientifically interesting from the standpoint of examining a man-made object that was exposed to outer solar system space for a long time. Sort of like LDEF without any tomatoes. > If the world gets its collective act together, that site may well be > a *shrine*, a century from now. It's not even completely outlandish > that someone reading this message might one day read that plaque. Put a dome over the thing and build the Smithsonain-Disney Moon Theme Park around it! -john- -- =============================================================================== John A. Weeks III (612) 942-6969 john@newave.mn.org NeWave Communications ...uunet!rosevax!bungia!wd0gol!newave!john =============================================================================== ------------------------------ Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 12 Nov 90 22:05:02 GMT From: elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@decwrl.dec.com (Ron Baalke) Organization: Jet Propulsion Laboratory, Pasadena, CA. Subject: Magellan Update - 11/12/90 Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu MAGELLAN STATUS REPORT November 12, 1990 The Magellan spacecraft performance is nominal. The spacecraft successfully accepted commands on Friday, November 9, resuming mapping on orbit 787 at 4:07 am PST on Saturday, November 10. One STARCAL (star calibration) occurs every orbit and 1 DESAT (desaturation of the reaction wheels) every 4th orbit. 16 STARCALS and 4 DESATS have been done since mapping resumed. A sequence patch to disable solar array control during mapping has prevented the spacecraft vibration from recurring. Track 1 of tape recorder B was successfully played back on November 9. It contains the results of STARCALS performed during Superior Conjunction. ___ _____ ___ /_ /| /____/ \ /_ /| | | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov ___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov /___| | | | ___/ | |/__ /| M/S 301-355 | |_____|/ |_|/ |_____|/ Pasadena, CA 91109 | ------------------------------ Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: Mon, 12 Nov 90 10:41:20 PST From: greer%utdssa.dnet%utadnx@utspan.span.nasa.gov X-Vmsmail-To: UTADNX::UTSPAN::AMES::"space+@andrew.cmu.edu" Subject: Re: Creationists and Moon Dust To: space+@andrew.cmu.edu In Subject: SPACE Digest V12 #525, optilink!cramer@uunet.uu.net (Clayton Cramer) writes: >In article , s64421@zeus.usq.EDU.AU (house ron) writes: >> Creationists around here are claiming that before the moon shots, >> scientists were worried about the space craft sinking in metres of >> dust which they thought should have accumulated since the moon was >>...(stuff deleted) >> Ron House. (s64421@zeus.usq.edu.au) >I've given up trying to intelligently argue with "creation >scientists". When I get the energy, I will be posting a review >of a wonderful book for dealing with creationists called _The_ >Fingerprint_Of_God_, written by a guy with a Ph.D. from University >of Toronto in astrophysics... >...(more stuff deleted) >Clayton E. Cramer {pyramid,pixar,tekbspa}!optilink!cramer This is straying pretty far from immediate Space Digest concerns, but I thought everybody might like to know that the 16 year reign of Creationists in the selection of Texas schoolbooks has been broken! This is important to the rest of the country because (for some reason) most states follow the Texas lead in schoolbook selection. Previously, Texas science textbooks were required to give equal treatment to creationism and evolution, with the result that there was very little about evolution and some textbooks dropped both subjects altogether. Last year the Texas schoolbook selection committee voted to include creationist objections to evolution only if they were rational and scientific, with the result that the new textbooks selected last week have no mention of creationism at all. Moral: if you keep at it long enough, and you get help in high places (in this case the Texas attorney general and H. Ross Perot), you can turn what seems a hopeless situation around. Maybe that will go for the US space effort too. _____________ Dale M. Greer, whose opinions are not to be confused with those of the Center for Space Sciences, U.T. at Dallas, UTSPAN::UTADNX::UTDSSA::GREER While the Bill of Rights burns, Congress fiddles. -- anonymous ------------------------------ Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 12 Nov 90 15:58:40 GMT From: mcsun!ukc!icdoc!syma!nickw@uunet.uu.net (Nick Watkins) Organization: University of Sussex Subject: Re: Call for new news group : sci.space.seds References: <1990Nov6.193929.6072@cc.ic.ac.uk> Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu From article <1990Nov6.193929.6072@cc.ic.ac.uk>, by zmapj36@cc.ic.ac.uk (M.S.Bennett Supvs= Prof Pendry): > founded 10 years ago to put pressure on congress to uncancel a number of > probe missions - in this it was successful. Which ones ? I know Planetary Society was involved in lobbying for Galileo & Mars Observer - what exactly did SEDS do ? Nick -- ------------------------------ Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 9 Nov 90 22:17:28 GMT From: mips!zaphod.mps.ohio-state.edu!samsung!umich!sharkey!cfctech!teemc!fmeed1!cage@decwrl.dec.com (Russ Cage) Organization: Ford Motor Co., Electronics Div., Dearborn, MI Subject: LLNL size and Fred micrograv environment (was LLNL astronaut delivery) References: <2669@polari.UUCP>, <9011072124.AA13810@iti.org>, <2688@polari.UUCP> Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu In article <2688@polari.UUCP> crad@polari.UUCP (Charles Radley) writes: >In <9011072124.AA13810@iti.org>, Allen Sherzer wrote: >+Actually, it makes micorgravity better. By putting the microgravity >+facility in a crew-tended free flyer it won't be subjected to the >+vibration which Freedom will subject it to. >- >True, but it won't benefit from continuous manned presence to fix >problems. Continuous manned presence *is* a problem for microgravity research. So is a shifting CG, which moves the experiments into regions of greater or lesser tidal force. This is not a benefit, it is a liability. Ask the micrograv researchers. A free-flyer can be tailored to the job, and does not suffer from vibration or CG shifts on the station proper. > For a free-flyer to fly "in-formation" with a nearby >manned base will require frequent disruptive thruster pulses, so it >is not totally quiet. Otherwise it would have to rely on nodal >regression to rendezvous with a station, with weeks or months of no >human access. On a free-flyer, thruster pulses can be scheduled to coincide with dead time, furnace re-loads, and so forth. It may mean a delay between the time something breaks and the time it can be fixed, but if something is broken you don't care about giving it a bit of gee, there is no processing to be disturbed. On a manned platform, you are going to have vibration any time the crew is moving around, which will be much of the time. There is work which cannot be done on a manned platform, and the Fred design doesn't allow for it at all. --------------------------------------------------------------- And now for the part I find confusing. This posting brings an apparent contradiction into sharp focus, because it holds both parts of it in more detail than ever before in this discussion: #1: >What commercial needs ? It puzzles me why people such as yourself >prefer a small station to a big one. Here you are apparently saying that the LLNL station would be smaller than Fred, but then you say... #2: >+Two Titans gives you more interior room than Freedom. >- >Interior volume is not particularly exciting, except for recreation. >Maybe useful if we ever get a space tourism industry up and running. >Right now more interested in maximum science for minimum weight and >cost. There you admit that LLNL would have more volume than Fred (and thus more room for equipment). Well, which is it? Or were you talking about Fred in #1, and not LLNL? If so, I'm sure there is an answer to your question. -- Russ Cage Ford Powertrain Engineering Development Department Work: itivax.iti.org!cfctech!fmeed1!cage (CHATTY MAIL NOT ANSWERED HERE) Home: russ@m-net.ann-arbor.mi.us (All non-business mail) Member: HASA, "S" division. ------------------------------ Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 12 Nov 90 13:50:11 GMT From: swrinde!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!watserv1!ria!uwovax!17001_1511@ucsd.edu Subject: angular momentum Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu Angular momentum in a system evolving towards synchronous rotation: Angular momentum has to be preserved - several people pointed this out - and it is. As the total rotational angular momentum changes due to slowing of rotation (on both bodies), the orbital characteristics of the system change in step. For instance, right now the Moon is in synchronous rotation, but Earth is not (the fully evolved system is that of Pluto and Charon, both rotating synchronously with their orbital motion with respect to each other). Therefore the Moon brakes the Earth, and the angular momentum which is lost from Earth's slowing is made up by an increase in the Moon's orbital radius. Phil Stooke, Department of Geography, University of Western Ontario, London, Ontario, Canada N6A 5C2 ------------------------------ Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 12 Nov 90 18:49:08 GMT From: swrinde!zaphod.mps.ohio-state.edu!samsung!rex!rouge!dlbres10@ucsd.edu (Fraering Philip) Organization: Univ. of Southwestern LA, Lafayette Subject: Re: You Can't Expect a Space Station to be Cheap References: <6762@hub.ucsb.edu>, <9010250032.AA13018@iti.org> Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu The following exchange has taken place: Russ Cage: Russ Cage had written: RC>Show me anything like SSX which has flown even 2 flights, and RC>come within a factor of 2 of its cost target. And I had responded: PF>Well, for starters, Max Hunter, SSX's main proponent, says that it is PF>less complex than a major airliner. To which Russ said: RC>1.) Has it flown? No. RC>2.) Has it come within 2x its cost targets? Unbuilt, so we don't know. And goes on in a similar fashion, best summarized by his summary line: RC>Summary: SSX is still a paper vehicle, and cannot be compared to expendables. You don't get it. I am saying that we should put our trust in people who have had success with launch technology before. Like Hunter, who allegedly built the Delta, which everyone talks about as a raging economic success. SSX basically has the same payload-to-weight ratio as Delta, but is reusable. Twenty years of advances in _structures_ (and computer design, computer control, manufacturing advances, and aerodynamics ought to enable us to use the H-2 or RL-10 in a reusable manner. It's not operational now, but if we start on it now we might have an operational vehicle by the time Freedom goes up. And given probable design changes in Freedom, such as the downsizing of the modules which might be about to take place due to center-of-gravity restraints on the shuttle (even a stripped full-size module allegedly fails this), Freedom could launch on SSX and the Shuttle, and we would have a backup system for the station. Phil ------------------------------ Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 12 Nov 90 20:00:10 GMT From: usc!elroy.jpl.nasa.gov!forsight!jato!mars.jpl.nasa.gov!baalke@ucsd.edu (Ron Baalke) Organization: Jet Propulsion Laboratory, Pasadena, CA. Subject: Galileo Update - 11/12/90 Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu GALILEO STATUS REPORT November 12, 1990 A command was sent today to the Galiloe spacecraft to reset the command loss timer to 216 hours, the planned value for this mission phase. Another delta DOR (Differential One-way Ranging) navigation activity was successfully completed today using using the 70 meter antenna pairs at Goldstone/Spain and Goldstone/Australia. The sequence memory load for TCM-7 (Trajectory Course Maneuver 7) will be sent to the spacecraft today. The spacecraft will execute the maneuver tomorrow using its axial and lateral thrusters. ___ _____ ___ /_ /| /____/ \ /_ /| | | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov ___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov /___| | | | ___/ | |/__ /| M/S 301-355 | |_____|/ |_|/ |_____|/ Pasadena, CA 91109 | ------------------------------ End of SPACE Digest V12 #551 *******************