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 ; Fri, 9 Feb 90 01:26:20 -0500 (EST) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Fri, 9 Feb 90 01:25:53 -0500 (EST) Subject: SPACE Digest V11 #22 SPACE Digest Volume 11 : Issue 22 Today's Topics: Re: Galileo Update - 02/06/90 (Forwarded) Systeme International (was Imperial measurements) Re: SPACE ACTIVIST ALERT Re: Gravity Assist Mechanism Re: Galileo Venus encounter (Re: Galileo Update - 02/07/90) Re: Furlongs per fortnight in space NSS and the National Space Council Re: furlongs per fortnight in space Re: Spacecraft drives and fuel efficiency Re: furlongs per fortnight in space Re: SPACE ACTIVIST ALERT NASA Select Radio Programs for 02/12/90 (Forwarded) Re: SPACE ACTIVIST ALERT ---------------------------------------------------------------------- Date: 8 Feb 90 06:28:53 GMT From: shlump.nac.dec.com!shodha.dec.com!thewav!pflueger@decwrl.dec.com (Free speech is a sound investment) Subject: Re: Galileo Update - 02/06/90 (Forwarded) Kenneth Arromdee writes... >Out of curiosity (and which I asked before): Is Galileo, when it reaches Earth, >going to take any pictures? (Maybe they can discover life :-)) ------------- Shouldn't that be intelligent life?? ;^) =Jp= +------------------------------------+-----------------------------------------+ Jim Pflueger [@thewav.enet.dec.com] | "History teaches that grave threats to Digital Equipment Corp. (CWO) | liberty often come in times of urgency, 3390 Harbor Blvd. | when constitutional rights seem too Costa Mesa, Ca. 92626 {Go Donks!} | extravagant to endure..." +(714)850-7745 ______________________+__Supreme Court Justice Thurgood Marshal_+ ------------------------------ Date: Thu, 08 Feb 90 11:48:32 EST From: JC%RMC.BITNET@vma.cc.cmu.edu Subject: Systeme International (was Imperial measurements) There are in fact several metric systems. The two most common are the centimetre-gram-second, usually known as CGS, and the metre-kilogram- second, officially known as SI (or as MKS by those who don't know better). CGS has about a dozen base units, from which other units are built. CGS includes many ancillary units, such as torr, atmospheres, stokes, and gauss. SI is the standard adopted by countries. It has many rules about the proper formation of symbols and prefixes, and even the spelling of units (it's metre and litre, not meter and liter... officially ;-). The Systeme International has only six base units (the metre, the kilogram, the second, the Ampere, the Kelvin, and the candela) and about 20 combination units (the Newton, etc). SI permits a small number of ancillary units. These fall into two categories: everyday units (litres, tonnes, degrees Celsius, hectares, and a couple of others I can't think of), and scientific units (the AU, the parsec, and the mole). Units such as the erg and the poise are not permitted for use with SI. John Coughlin Net: JC@RMC.BITNET Vox: 613-541-6439 Fax: 613-547-3053 ------------------------------ Date: 8 Feb 90 08:48:19 GMT From: agate!usenet@ucbvax.Berkeley.EDU (William Baxter) Subject: Re: SPACE ACTIVIST ALERT In article <4888@itivax.iti.org>, ttf@vax3 (Tihamer T. Toth-Fejel) writes: >Sandy Adamson would have made the decision on whether or not to >activate the phone tree, but felt that her involvement with space >station would prejudice her decision, so she had Pace make the >decision. This is incorrect. In Denver at the NSS conference to years ago, Pace tried to take credit for having made the decision against activating the phone tree. But Adamsen blew it and said that it was in fact her decision. So there was both conflict of interest and awareness of that conflict. William Baxter ARPA: web@{garnet,brahms,math}.Berkeley.EDU UUCP: {sun,dual,decwrl,decvax,hplabs,...}!ucbvax!garnet!web ------------------------------ Date: 8 Feb 90 16:20:01 GMT From: cs.utexas.edu!usc!brutus.cs.uiuc.edu!ux1.cso.uiuc.edu!uxh.cso.uiuc.edu!jep@tut.cis.ohio-state.edu (John E. Prussing) Subject: Re: Gravity Assist Mechanism In article <1990Feb7.133825.18100@axion.bt.co.uk> apengell@axion.bt.co.uk (alan pengelly) writes: > > Here in the UK we recently had a couple of TV programs summarise the VOYAGER >missions. Firstly we would like to say to all those at NASA 'well done'. The >whole thing has been quite awe inspiring. But it also gave a couple of >computer scientists a problem. We thought we knew all about gravity assist >unitl we actually sat down and tried to work out the mechanism involved. We >have been arguing ever since. We have two schools of thought. > >1) Angular momentum is transferred from the planet too the spacecraft. The > increased velocity of the spacecraft after the encounter is at the > expense of the planets angular momentum, so it rotates more slowly. > >2) It is the kinetic energy of the planet that it transferred. Thus the > planets orbital period increases ( but then surely the planet would > adopt an orbit closer to the sun?) > >Is there anybody out there that has a detailed understanding of gravity >assist? We would greatly appreciate some enlightenment of this subject. > >Thanks in advance > >Alan Pengelly #2 is basically correct, except that if the spacecraft's orbital velocity is increased, the planet's velocity is decreased, resulting in a smaller planet orbital period (smaller semimajor axis). Because the mass ratio spacecraft-to-planet is EXTREMELY small, the decrease in planet orbital period is negligible. =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- John E. Prussing Internet: jep@uxh.cso.uiuc.edu Aeronautical & Astronautical Engineering University of Illinois at Urbana-Champaign Bitnet: jep@uiucuxh ------------------------------ Date: 8 Feb 90 19:15:49 GMT From: pacific.mps.ohio-state.edu!zaphod.mps.ohio-state.edu!brutus.cs.uiuc.edu!jarthur!jokim@tut.cis.ohio-state.edu (John H. Kim) Subject: Re: Galileo Venus encounter (Re: Galileo Update - 02/07/90) In article <2055@eric.mpr.ca> fischer@dssmv2.UUCP (Roger Fischer) writes: > >2.) What is the heliocentric velocity of Venus and Earth compared > to the current and after-encounter velocity of Galileo. I vaguely remember a crazed/bored astrophysicist answering a similar question concerning the Voyager 2 - Jupiter encounter. After a year or so, Jupiter was only the radius of a hydrogen atom behind where it would have been had the V2 encounter never happened. -- John H. Kim | (This space to be filled when I jokim@jarthur.Claremont.EDU | think of something very clever uunet!muddcs!jarthur!jokim | to use as a disclaimer) ------------------------------ Date: 6 Feb 90 20:53:50 GMT From: ucsdhub!hp-sdd!ncr-sd!ncrcae!usceast!uscacm!p6.f12.n376.z1.FIDONET.ORG!Shay.Walters@ucsd.edu (Shay Walters) Subject: Re: Furlongs per fortnight in space In message <496@fsu.scri.fsu.edu>, pepke@gw.scri.fsu.edu (Eric Pepke) writes: Speaking of schoolchildren, the way schools teach them about the metric system is dumb, too, and perhaps the dumbness of the teaching methods contributes to the perception that the metric system is hard. Schools teach, for example, that one inch is 2.54 centimeters. Ability to do the conversion is often used as a test of "understanding." I think you've hit the nail on the proverbial head there. I hear no end of people who don't want to learn the metric system because "it's so complicated - there's all that multiplying and dividing to do!" Learning the metric system in terms of english measurement is ridiculous. I've even seen billboards by the road (sponsored by some gov't agency promoting metric conversion) which, in huge letters, said "One Inch = 2.54 cm". How much better it would have been if the sign had said "This billboard is 3 meters tall and 9 meters wide"! How many people have an intuitive understanding of what an inch is to three significant figures? Even when I used to do a lot of machining to the thousandth of an inch I couldn't do that. It's tragigally humorous to see "net wt. approx 10 oz. (283 grams)" or "Useable 0 - 400 F (-17.77 - 204 C)". It illustrates that even the people responsible for indicating these measures don't understand what they're doing. (Sorry for getting off-topic). -- -- Shay Walters == ...!usceast!uscacm!12.6!Shay.Walters ------------------------------ Date: 8 Feb 90 10:28:41 GMT From: agate!usenet@ucbvax.Berkeley.EDU (William Baxter) Subject: NSS and the National Space Council During a recent fund raising call from the NSS, the caller informed me that the National Space Council had requested that NSS boost grass roots support for their policies. This is an opportunity for NSS members to engage in pro-space activity. Call the National Space Council (202/395-6175) and ask them what you can do as a member of the NSS to promote their proposals. William Baxter ARPA: web@{garnet,brahms,math}.Berkeley.EDU UUCP: {sun,dual,decwrl,decvax,hplabs,...}!ucbvax!garnet!web ------------------------------ Date: 7 Feb 90 11:34:09 GMT From: swrinde!cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo!sq!msb@ucsd.edu (Mark Brader) Subject: Re: furlongs per fortnight in space I've been waiting for someone to correct the speed of light given as: > 901306800000 furlongs/fortnight --- it's not just a good idea, it's the law. The actual number is of course 1802617499785 + 355/1397, or if you prefer, __________________________________________ 1802617499785.254115962777380100214745884037222619899785 furlongs/fortnight. (Yes, exactly. The meter is so defined that the speed of light is exactly 299792458 m/s, and the inch is defined as .0254 m, and the rest is obvious.) -- Mark Brader "... there is no such word as 'impossible' in SoftQuad Inc., Toronto my dictionary. In fact, everything between utzoo!sq!msb 'herring' and 'marmalade' appears to be missing." msb@sq.com -- Douglas Adams: Dirk Gently's Holistic Detective Agency This article is in the public domain. ------------------------------ Date: 9 Feb 90 00:27:43 GMT From: portal!portal!cup.portal.com!hkhenson@apple.com (H Keith Henson) Subject: Re: Spacecraft drives and fuel efficiency A civilization actually able to travel between the stars it seem likely to me is going to be tapping stars for energy. We already know of one way to do that, build a bunch of monster solar power plants, and convert the energy to laser light. Lasers will levitate against 1g, and as someone (Henry?) recently said, a year at one gee is the speed of light. (How to stop is left as an exercise) Keith Henson ------------------------------ Date: Thu, 08 Feb 90 14:05:20 GMT From: ZZASSGL%cms.manchester-computing-centre.ac.uk@NSFnet-Relay.AC.UK Myname: Geoff. Lane. (Phone UK-061 275 6051) Subject: Re: furlongs per fortnight in space > that the mile figures would eventually be taken down, so the kilometer > figures were taken down instead. In that climate of public opinion, do > any of you Europeans/Canadians/etc. have any ideas on how to get the > American public to switch over? (I don't think summary executions would > be acceptable. :-) In the UK things are, as described before, still mixed. However if you go into a primary school (ie for those < 11 years old) everything is in SI; with the addition of litres etc. As the old generation dies off, the children will become more influential and more general use of SI will occur. You will never complete the change - there are parts of France that still use measures very close to the pound and foot despite the Revolution. Until quite recently certain food stuffs and liquids could legally only be sold in Imperial measures (Sugar in lbs, milk in pints etc) but this has now changed. ------------------------------ Date: 8 Feb 90 17:44:50 GMT From: swrinde!cs.utexas.edu!samsung!umich!sharkey!itivax!vax3!aws@ucsd.edu (Allen W. Sherzer) Subject: Re: SPACE ACTIVIST ALERT In article <1990Feb8.084027.25658@agate.berkeley.edu> web@garnet.berkeley.edu (William Baxter) writes: >>> Remove Scott Pace from the Department of Commerce's space office. >>I am pleased to see Scott Pace in Washington and wish him the best of luck. >>He is a real grassroots activist who finally will be in a position to >>... >Translation: Dale doesn't know what a space activism is, but knows that >Pace silently follows sci.space. I am not expressing an opinion either way on Scott Pace; I don't know him or the situation well enough. However, I would like to point out: 1. He is in the job now. As a civil servent it is almost impossible to fire him and a bunch of phone calls won't do the job. In other words, the job is his and nothing can be done to stop it. 2. If he does silently read the net and you antagonize him he will not be disponsed to do what you want. You need him more than he needs you. You should consider the advantages of trying to work with they guy instead of against him. You may just find you both get something out of it. Allen ---------------------------------------------------------------------------- | Allen W. Sherzer | Cthulhu for President - | | aws@iti.org | If you're tired of choosing the LESSER of 2 evils | ---------------------------------------------------------------------------- ------------------------------ Date: 9 Feb 90 01:44:15 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: NASA Select Radio Programs for 02/12/90 (Forwarded) The next series of NASA radio programs will be on NASA Select Monday, February 12th at 1:00 p.m. Eastern. The shows include: #1364 "Ice Haze De-Glazed" (Feat: Tom Bond, LeRC) USE: 02/12/90 thru 02/18/90 #1365 "Lunch For The Moon/Mars Crowd" (Feat: R. Prince, J. Sager and R. Wheeler, KSC) USE: 02/19/90 thru 02/25/90 #1366 "Martians Wanted -- Dead or Alive" (Feat: Chris McKay, ARC) USE: 02/26/90 thru 03/04/90 #1367 "Aircraft of Tomorrow" (Feat: John Davis, LaRC) USE: 03/05/90 thru 03/11/90 NASA Select is on Satcom F-2R, Transponder 13, 72 West Longitude. ------------------------------ Date: 8 Feb 90 08:40:27 GMT From: agate!usenet@ucbvax.Berkeley.EDU (William Baxter) Subject: Re: SPACE ACTIVIST ALERT In article <3707@cbnewsj.ATT.COM>, skran@cbnewsj (dale.l.skran) writes: >In article <9001300244.AA21250@trout.nosc.mil>, jim@pnet01.cts.COM (Jim Bowery) writes: >> >> >> OBJECTIVE >> >> Remove Scott Pace from the Department of Commerce's space office. >> >> * Is considered by most activists as working against HR2674 >A lie. Scott has always supported HR2674, and worked to make it a reality. Wrong. He made no use of his position at NSS to support the bill. At an NSS Legilative Committee meeting last May, he said that they should try to associate themselves with the bill even though they had not done anything with it. He seems to have convinced you. >> * Has virtually no commercial experience >Has tons of space policy experience. His Rand Corp. papers on space policy are disorganized, illogical, and void of content. But they have lots of figures. >> * Is heavily affiliated with government space interests through his employment >> at the RAND Corporation and position of authority in the National Space >> Society and its political organizations >Translation: has done more for the pro-space movement than Bowery will > ever do. Read his papers. They are probably in a univerity library near you. >I am pleased to see Scott Pace in Washington and wish him the best of luck. >He is a real grassroots activist who finally will be in a position to >have some real effect on what we are doing in space. Those of you on the >net who are serious about the pro-space movement would do well to imitate >Scott and ignore Bowery's flames. Translation: Dale doesn't know what a space activism is, but knows that Pace silently follows sci.space. William Baxter ARPA: web@{garnet,brahms,math}.Berkeley.EDU UUCP: {sun,dual,decwrl,decvax,hplabs,...}!ucbvax!garnet!web ------------------------------ End of SPACE Digest V11 #22 *******************