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, 12 May 90 01:28:50 -0400 (EDT) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sat, 12 May 90 01:28:18 -0400 (EDT) Subject: SPACE Digest V11 #389 SPACE Digest Volume 11 : Issue 389 Today's Topics: Re: Apollo 12 Re: Apollo 12 this is a test... disregard if you receive this Re: Manned Mission To Venus Re: Niven's Inertialess Drive Re: Hubble Space Telescope Update - 05/09/90 (Forwarded) Re: launch windows Re: why there are no ETs Re: Terraforming Venus/Mars Re: Terraforming Venus (was: Manned mission to Venus) Re: Terraforming Venus (was: Manned mission to Venus) Re: Terraforming Venus (was: Manned mission to Venus) Space List ---------------------------------------------------------------------- Date: 10 May 90 20:00:18 GMT From: cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!mips!prls!philabs!briar!rfc@tut.cis.ohio-state.edu (Robert Casey) Subject: Re: Apollo 12 In article <5724@hplabsb.HP.COM> dsmith@hplabsb.UUCP (David Smith) writes: >Gregory Bond asked why launch windows happened only a few days a month. >They wanted to land with a low sun angle, to bring out the relief at the >landing site. If they waited too long, the sun would be too high. I >presume they didn't want to land near sunset, because if landing or lunar >takeoff were delayed, they would end up in the dark. If they were a few days late launching, why not land at another selected spot on the Moon where the Sun angle would be good at that time? I'm assuming that the site selection committee had selected more than one site. And in the early flights, one easy spot is as good as another, if your main objective is to get the flight in before the end of the decade. Maybe the problem would be the lack of computing capability to get the later flight planned out in full? ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ A notice attached to a piece of equipment made in Japan: "It put on the vinyl sheet on the surface of upper & lower panel for the protection Please use after tear off vinyl sheet when using." --ShibaSoku Co., Ltd. ------------------------------ Date: 11 May 90 16:21:09 GMT From: hplabsb!dsmith@hplabs.hp.com (David Smith) Subject: Re: Apollo 12 In article <94950@philabs.Philips.Com> rfc@briar.philips.com.UUCP (Robert Casey) writes: >If they were a few days late launching, why not land at another >selected spot on the Moon where the Sun angle would be good at that >time? I'm assuming that the site selection committee had selected more >than one site. And in the early flights, one easy spot is as good as >another, if your main objective is to get the flight in before the end >of the decade. The crew's preparation was for one landing site. Once the LM pitched over so they could see the surface, they started navigating (or checking navigation) by landmarks they had drilled into memory. During the moonwalks and drives, they had a specific well-learned itinerary, which in the case of Apollo 12 included visiting a Surveyor. -- David R. Smith, HP Labs dsmith@hplabs.hp.com (415) 857-7898 ------------------------------ Date: Fri, 11 May 90 18:41 CDT From: Buckaroo Bonzai and the Team of Baker Street Irregulars Subject: this is a test... disregard if you receive this To: NEXT-L@BROWNVM.BITNET, INFO-UNIX@BRL.ARPA, TCP-IP@NIC.DDN.MIL, DLV@CUNYVMS1.BITNET, GAELIC-L@IRLEARN.BITNET, Info-Mac@sumex-aim.stanford.edu, space+@andrew.cmu.edu, I-PACRAD@UIUCVMD.BITNET, Packet-Radio@UCSD.Edu, Info-IBMPC@WSMR-SIMTEL20.ARMY.mil X-Envelope-To: space+@andrew.cmu.edu X-Vms-Cc: ELEE6WK this is a test.. please disregard if you get this... my mail router here at the university of houston has died a death or two. william sanders, a subscriber to this list ------------------------------ Date: Fri, 11 May 90 17:19:57 CDT From: mccall@skvax1.csc.ti.com Subject: Re: Manned Mission To Venus > clyde.concordia.ca!mcgill-vision!quiche!calvin!msdos@uunet.uu.net (Mark SOKOLOWSKI) > When I was talking "cultural", I was talking about the soil composition, > landscape features, and gravity, which would make life on Venus so much > similar to those of Earth's. Hmmm, not sure how soil composition, landscape features and gravity became *cultural*, but we'll let that pass. It's quite simply plain silly to think that "life on Venus [would be] so much similar to those of Earth's". > [Much ranting about "challenge", "adventure", "excitement" and > such deleted.] I've got an idea for Mr. Sokolovski. Rather than going to Venus, why not launch a pair of missions; one to land on the Sun and one to land on Jupiter. Now *there* would be "challenge", "adventure", and "excitement"! It also wouldn't be *that* much more difficult than staying on Venus. I fail to understand how anyone who is 20 could still be so grossly misinformed about what is reasonable/possible within the realm of the current technology. ============================================================================== | Fred McCall (mccall@skvax1.ti.com) | "Insisting on perfect safety is for | | Advanced Systems Division | people who don't have the balls to | | Defense Systems & Electronics Group | live in the real world." | | Texas Instruments, Inc. | -- Mary Shafer | +-------------------------------------+--------------------------------------+ | I speak for me. I don't speak for others, and they don't speak for me. | ============================================================================== ------------------------------ Date: Fri, 11 May 90 17:16:25 CDT From: mccall@skvax1.csc.ti.com Subject: Re: Niven's Inertialess Drive I find myself under the impression that the 'inertialess drive' was invented by the Kzinti, and that it was acquired at the end of the First Man-Kzin War. This is why the Kzinti were so surprised upon their invasion of the Solar System and the root of the Kzinti Lesson about fusion drives. [I have a copy of _The Man-Kzin Wars_ at home somewhere. Maybe I need to dig it up and see if this is mentioned.] ============================================================================== | Fred McCall (mccall@skvax1.ti.com) | "Insisting on perfect safety is for | | Advanced Systems Division | people who don't have the balls to | | Defense Systems & Electronics Group | live in the real world." | | Texas Instruments, Inc. | -- Mary Shafer | +-------------------------------------+--------------------------------------+ | I speak for me. I don't speak for others, and they don't speak for me. | ============================================================================== ------------------------------ Date: 11 May 90 06:47:39 GMT From: usc!cs.utexas.edu!texbell!texsun!csccat!jack@ucsd.edu (Jack Hudler) Subject: Re: Hubble Space Telescope Update - 05/09/90 (Forwarded) In article <3620@jato.Jpl.Nasa.Gov> baalke@mars.jpl.nasa.gov (Ron Baalke) writes: >"Hubble Space Telescope's First Picture Could Come Wednesday" > >Rosenthal says the picture would be of a 3-billion-year-old star >field called Theta Carina, or "Ship's Keel," located in the >southern sky and that the star cluster is 1,260 light years away >and visible with the naked eye in Africa, South America and >Australia. I figures, tha %*&^%*s wouldn't image anything we can compare it to up here! -- Jack Computer Support Corportion Dallas,Texas Hudler UUCP: {texsun,texbell}!csccat!jack ------------------------------ Date: 11 May 90 15:51:16 GMT From: clyde.concordia.ca!news-server.csri.toronto.edu!utgpu!utzoo!henry@uunet.uu.net (Henry Spencer) Subject: Re: launch windows In article <40880@apple.Apple.COM> winter@Apple.COM (Patty Winter) writes: >What I've been trying to figure out (and some of my friends say the >same) is why there was a "launch" (release) window for HST.... As I recall, the biggest constraint was that the deployment of the solar arrays finish at "sunrise" (passage out of the Earth's shadow) to give maximum opportunity for battery charging at the first possible moment. The power umbilical from the orbiter had to be disconnected before the start of deployment, so HST was on batteries thereafter, and they were *very* concerned about making sure that it not drain them dry. -- Life is too short to spend | Henry Spencer at U of Toronto Zoology debugging Intel parts. -Van J.| uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 11 May 90 00:45:15 GMT From: bfmny0!tneff@uunet.uu.net (Tom Neff) Subject: Re: why there are no ETs In article <1990May11.052904.11302@cs.rochester.edu> yamauchi@cs.rochester.edu (Brian Yamauchi) writes: >[me] >>I still like my explanation. When you achieve interstellar travel >>or communication, someone comes along and kills you. > >Which also has the same flaw mentioned above -- it assumes the killers >are able to succeed in all cases. I can believe in berserkers, but >not in omniscient, omnipotent berserkers. Aw come on. If you know how to move asteroids around you can take out Earth's higher civilization RIGHT NOW. Splash a few of them and we're back to the Dark Ages just like >that<. If we're lucky. And we won't claw our way up to today's golden age in 600 years like last time either, because Earth's climate will SUCK and we already took all the easy minerals. The survivors will be SOL for millenia at best. If the exterminators stick with the program a little longer, I don't think we need to worry about any survivors. Maybe SETI should stand for Search for Extra-Terrestrial Insects. The nice part about my theory is that you only need ONE berserker race to make it work. The first ones to learn how to move around and do their jobs, make everything else neat. My second theory is that everyone figures out the first theory and clams up out of paranoia. :-) -- War is like love; it always \%\%\% Tom Neff finds a way. -- Bertold Brecht %\%\%\ tneff@bfmny0.UU.NET ------------------------------ Date: 11 May 90 17:27:30 GMT From: mcsun!inesc!unl!unl!ray@uunet.uu.net (Vitor Duarte & Sergio Duarte) Subject: Re: Terraforming Venus/Mars Two habitable planets for the price of one: take the excedent CO2 from Venus to Mars... -- --- Sergio Duarte BITNET/Internet: ray@fctunl.rccn.pt +---------------------------------+ UUCP: ray@unl.uucp | Departamento de Informatica +----------------------------------+ | F.C.T. / Universidade Nova de Lisboa | +--------------------------------------------------------------------+ ------------------------------ Date: 11 May 90 09:04:24 GMT From: zaphod.mps.ohio-state.edu!samsung!munnari.oz.au!uluru5!danielce@tut.cis.ohio-state.edu (Daniel Ake CAROSONE) Subject: Re: Terraforming Venus (was: Manned mission to Venus) In article , eb1z+@andrew.cmu.edu (Edward Joseph Bennett) writes: >> [using ice from Saturn's rings is BAD IDEA] > Good point. We can use rings from Jupiter or Neptune or some set of > rings that is not as spectacular. Would we have to use enough of the > rings to make a noticable difference anyhow? As I understand it, such a system is drectly under the influence of chaos. ie make a small change in initial conditons, and the resulting system n time units later is vastly different to that if no change had been made. Admittedly this is in reference to the positions of individual particles within the rings, but I think that any amount of ice removed that would help at all on venus would effect drastic change to the rings. Note to future^n readers: Please Don't! ------------------------------ Date: 11 May 90 18:31:24 GMT From: hagerp@iuvax.cs.indiana.edu (Paul Hager) Subject: Re: Terraforming Venus (was: Manned mission to Venus) jdnicoll@watyew.uwaterloo.ca (Brian or James) writes: ] I think using Saturn's rings as H2O fodder for terraforming ]Venus is a Bad Idea. There are other sources of ice in the ]Solar System, and destroying a beautiful ring sytem unecessarily ]seems wrong. Kind of similar logic to national parks or ]historic buildings. The Rings have a value where they are. ] JDN I think the poster raises an interesting problem -- aesthetics versus utilities. We see this polarity reflected in ideologies and politics today and as we push out into space there is no reason to assume that we won't carry our culture and attitudes with us. Personally, I'd dismantle the rings in a New York minute if I could terraform a planet in the process. This puts me at the opposite pole. If the people who move out are no-nonsense, utilitarian types like me then I venture to say that political suasion will not prevail against the advantages the colonists would have with access (the laws of physics being what they are). However, I'd expect a few poets and aesthetes would be along on the trip out -- enough to curb the worst excesses of people like me. In the end I'm sure some compromise will be worked out -- it usually is. Politics in the 22nd Century promises to be a real gas. -- paul hager hagerp@iuvax.cs.indiana.edu "I would give the Devil benefit of the law for my own safety's sake." --from _A_Man_for_All_Seasons_ by Robert Bolt ------------------------------ Date: 11 May 90 20:56:37 GMT From: thorin!homer!leech@mcnc.org (Jonathan Leech) Subject: Re: Terraforming Venus (was: Manned mission to Venus) In article <44694@iuvax.cs.indiana.edu> hagerp@iuvax.cs.indiana.edu (Paul Hager) writes: >Personally, I'd dismantle the rings in a New York minute if I >could terraform a planet in the process. Why bother, when perfectly good ice moons like Enceladus are available (as Dyson originally proposed - nobody seems to be giving credit where due). -- Jon Leech (leech@cs.unc.edu) __@/ ``The tuba recital is one of the most memorable experiences of music school.'' - Seen on a bulletin board in the UNC Music School ------------------------------ Date: Fri, 11 May 90 13:05:37 PDT From: greer%utdssa.dnet%utadnx@utspan.span.nasa.gov X-Vmsmail-To: UTADNX::UTSPAN::AMES::"space+@andrew.cmu.edu" Subject: Space List Space List: What every Space Enthusiast Should Know A List of Numbers and Equations Relevant to Space Exploration courtesy Dale M. Greer Numbers 9.8 m/s^2 ( 10) -- Acceleration at surface of Earth (one g) 7726 m/s (8000) -- Earth orbital velocity at 300 km altitude 3075 m/s (3000) -- Earth orbital velocity at 35786 km (geosync) 6371 km (6400) -- Mean radius of Earth (Re) 6378 km (6400) -- Equatorial radius of Earth (Re) 1738 km (1700) -- Mean radius of Moon (Rm) 5.974e24 kg (6e24) -- Mass of Earth (Me) 7.348e22 kg (7e22) -- Mass of Moon (Mm) 1.989e30 kg (2e30) -- Mass of Sun (Ms) 3.986e14 m^3/s^2 (4e14) -- Gravitational constant times mass of Earth 4.903e12 m^3/s^2 (5e12) -- Gravitational constant times mass of Moon 1.327e20 m^3/s^2 (13e19) - Gravitational constant times mass of Sun 384401 km ( 4e5) -- Mean Earth-Moon distance 1.496e11 m (15e10) - Mean Earth-Sun distance (Astronomical Unit) 1371 W/m^2 (1400) -- Mean solar constant at 1 AU Conversions 1.61 km / mi 0.0254 m / in 3.28 ft / m 0.3048 m / ft 1.467 fps / mph (or 88 fps = 60 mph, exactly) 0.447 m/s / mph 2.2 lb / kg (2.2 pounds-mass, that is) Comparisons 1 MJ = 0.28 kW hr Equations Where d is distance, v is velocity, a is acceleration, t is time. For constant acceleration d = d0 + vt + .5at^2 v = v0 + at v^2 = 2ad General Gravity f = G m1 m2 / r^2 a = v^2 / r g = G Me / r^2 For circular Keplerian orbits, where u is gravitational constant, a is semimajor axis of orbit, P is period. v^2 = u/a P = 2pi/(Sqrt(u/a^3)) Miscellaneous f = ma -- Force is mass times acceleration w = fd -- Work (energy) is force times distance Atmospheric density varies as exp(-mgz/kT) where z is altitude, m is molecular weight in kg of air, g is acceleration of gravity, T is temperature, k is Bolztmann's constant. Up to 100 km, d = d0*exp(-z*1.42e-4) where d is density, d0 is density at 0km, is approximately true, so d@12km (13000 m -- 40000 ft) = d0*.18 d@9 km ( 9800 m -- 30000 ft) = d0*.27 d@6 km ( 6500 m -- 20000 ft) = d0*.43 d@3 km ( 3300 m -- 10000 ft) = d0*.65 Selected Planetary Data Semimajor Axis Sidereal Synodic Incl.to Grav.Cst. Mass Period Period Eclipt. GM (10^12 (AU) (Mm) (Tr.Y.) (Days) (deg) m^3/s^2) 10^24kg Mercury 0.3871 57.9 0.24085 115.88 7.0042 22.03 0.33022 Venus 0.7233 108.2 0.61521 583.92 3.3944 324.86 4.8690 Earth 1.0000 149.6 1.00004 403.50 6.0477 Mars 1.5237 227.9 1.88089 779.94 1.8500 42.83 0.64191 Jupiter 5.2028 778.3 11.86223 398.88 1.3047 126712.0 1899.2 Saturn 9.5388 1427.0 29.4577 378.09 2.4894 37934.0 568.56 Uranus 19.1819 2869.6 84.0139 369.66 0.7730 5803.2 86.978 Neptune 30.0578 4496.6 164.793 367.49 1.7727 6871.3 102.99 Pluto 39.44 5900 247.7 366.73 17.17 40 0.7 The Moon 384.4 27.3217days 4.90 0.073483 (Suggestions? Favorite numbers, equations? Some rocketry info would be nice.) ------------------------------ End of SPACE Digest V11 #389 *******************