Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from hogtown.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 ; Tue, 5 Mar 91 01:24:04 -0500 (EST) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Tue, 5 Mar 91 01:23:58 -0500 (EST) Subject: SPACE Digest V13 #225 SPACE Digest Volume 13 : Issue 225 Today's Topics: Re: Lunar oxygen Galileo Update - 03/01/91 external tank use, practical issues thereof WWN does it again! Re: Terraforming, ethics of human existance. I-CON X Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription requests, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: Fri, 1 Mar 91 19:24:35 EST From: John Roberts Disclaimer: Opinions expressed are those of the sender and do not reflect NIST policy or agreement. To: polari!crad@cmr.ncsl.nist.gov, space@andrew.cmu.edu Subject: Re: Lunar oxygen >Date: 1 Mar 91 01:28:00 GMT >From: hub.ucsb.edu!ucsbuxa!3001crad@ucsd.edu (Charles Frank Radley) >Subject: Re: Space Profits >The advantages of lunar oxygen (Lunox):- >Delta-vee to LEO from Luna is much less than from Earth to LE O >Hence getting LOX to LEO is cheaper if it originates from the >Moon. To be fair, - LOX will cost much more per pound on the surface of the moon than on the surface of the earth. - Delta-V will initially cost much more per kg * m/s from the moon than from earth. It may eventually cost much less, if a linear launcher is built on the moon. (On the other hand, the same might be done on Earth.) So there's a tradeoff, with an accurate cost comparison requiring careful analysis. I think it's worth looking into. >LOX is a very valuable commodity to have in LEO because it can be >used to boost satellites from LEO to high orbit, eg >communications satellites. It can also be used to prevent >spacecraft in LEO (eg Space Stations) from decaying. >GEO comprises Oxidizer. Cheap Lunox would thus dramatically >reduce the cost of launching spacecraft into GEO. Please elaborate. John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: 2 Mar 91 01:06:03 GMT From: elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@decwrl.dec.com (Ron Baalke) Subject: Galileo Update - 03/01/91 GALILEO STATUS REPORT March 1, 1991 The status of the Galileo spacecraft as of end of the day of February 28 is as follows: o System Power Margin - 64 watts o Spin Configuration - Dual-Spin - cruise mode o Spin Rate/Sensor - 3.15 rpm o Spacecraft Attitude Sun Point Angle - approximately 3.7 degrees (lagging) plus or minus 0.3 degree o Downlink telemetry rate/antenna - 40 bits/second (uncoded)/LGA-1 (Low Gain Antenna-1) o General Thermal Control - all temperatures within acceptable range o RPM Tank Pressures - all within acceptable range o Probe - powered off, temperatures nominal o Command Loss Timer Setting - 240 hours Time To Initiation - 216 hours Today, the spacecraft activities will consist of: o Powering on the EPD (Energetic Particles Dectector) instrument for its periodic motor maintenance activity. o Performing a SITURN activity to lead the sun. o Performing an EUV (Extreme Ultraviolet Spectrometer) memory readout. No spacecraft activities are planned over the weekend. A total of 3239 real-time commands have been transmitted to Galileo. Of these, 1803 have been pre-planned in the sequence design and 1436 were not. In the past week, a total of 19 real-time commands were sent; one was pre-planned. ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | Is it mind over matter, ___| | | | |__) |/ | | |___ M/S 301-355 | or matter over mind? /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Never mind. |_____|/ |_|/ |_____|/ | It doesn't matter. ------------------------------ Date: 1 Mar 91 22:18:52 GMT From: ucivax!jarthur!elroy.jpl.nasa.gov!sdd.hp.com!cs.utexas.edu!news-server.csri.toronto.edu!utzoo!henry@ucbvax.Berkeley.EDU (Henry Spencer) Subject: external tank use, practical issues thereof In article <9363@hub.ucsb.edu> 3001crad@ucsbuxa.ucsb.edu (Charles Frank Radley) writes: >+... Anywhere you can >+bolt a hatch you can bolt an airlock instead, without any >+fundamental difficulties. >- > ?? Really.... Would not hold pressure very long ! Airlocks >involve complex redundant labyrinth seals. A bolted interface >is no good. References, please. I would be somewhat surprised to see labyrinth seals used in airlocks at all, because they do *not* stop leakage, they only slow it down -- they are normally used only in cases like rotating shafts where a bolted/latched interface seating on a gasket is impractical. My references don't specify what the shuttle airlock uses, but the side hatch uses latches and a gasket, and the same was true of the Apollo hatches. The Apollo docking interface used latches and gaskets. For that matter, bolts and gaskets are the normal sealing technology ground-based in vacuum, high-vacuum, and ultrahigh-vacuum systems. Bolted interfaces work just fine. If you want still another example, the Gamma-Ray Imaging Telescope project plans to use the (bolted, gasketed) seals on the external-tank access hatches to hold gas pressure inside for years, with no resupply flights and only a limited make-up supply on board. >+ As I may have mentioned before, the people working on the >+Gamma-Ray Imaging Telescope concept have already sorted out >+the details of opening one of the hydrogen-tank manholes and >+getting both men and equipment in through it. No major problems... >- > Interesting. Please tell us how they plan to install an >airlock. Windows would be nice too. Which of them volunteered >to be the first one to go through the airlock without a suit on ? None of them. You didn't read what I wrote. They're not putting in an airlock at all. However, they *are* moving both men (in spacesuits) and equipment into the interior during construction work. They think the access manholes are entirely adequate for the job. >+ Unbolt a manhole, slide in an airlock with a mounting flange >+matching the outer rim of the manhole cover, and bolt it >+ down. Bingo. >- > Sorry, you just failed the leak test. Start again. I'd be very curious to hear the details of this "leak test", and how an Apollo spacecraft docked to Skylab passed it. (Yes, the connecting tunnel was normally pressurized, and open to Skylab in fact.) > Nobody has ever installed a kluge fit airlock in orbit, not >even the Soviets want to be the first to take that risk. Both the US and Soviets have docked spacecraft to each other in orbit numerous times, with pressurized tunnels connecting them. Where is the problem with docking an airlock instead? If anything, we can do a better job on the airlock joint, since it will not have to undock again and it can be firmly bolted in place with a plastic-deformation gasket. (This is what is normally done in ultrahigh-vacuum systems: the gasket is a one-use type that is, literally, crushed between joint surfaces.) >+There is a 46x52-inch access door in the side of the intertank >+structure... Please be specific about *why* +breaching this >area is a no-no. >+ > There is nothing wrong with breaching the intertank area from >the outside. What I meant was breaching the barrier between the >two tanks, explosive mix and all that. This means that there is >no communication or acess possible from one tank to the other. >As well as an airlock to the outside, holes must be cut in the >two tanks then they will need a hermetically sealed tunnel to >connect them... Please go back and re-read my previous posting. There are *already* access hatches from both tanks into the intertank area; that is the only access hatch in the oxygen tank, in fact. No cutting will be needed. It ought to be possible to pre-install the tunnel, although it may add some small complexity to the system that maintains an inert atmosphere in the intertank area. (Yes, there is such a system, although I'm not sure of the details.) After the tanks have been vented to space, there will be no possibility of an explosive mixture and hence no problem in opening up the tunnel hatches, although this would probably have to be done by going in through the side door and opening a side hatch on the tunnel, since the hydrogen-tank hatch is undoubtedly not designed to be opened from inside! -- "But this *is* the simplified version | Henry Spencer @ U of Toronto Zoology for the general public." -S. Harris | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 3 Mar 91 18:39:15 GMT From: uokmax!jabishop@apple.com (Jonathan A Bishop) Subject: WWN does it again! Yes, folks, the Weekly World News, the people who brought you the hidden Challenger transcripts, have done it again! They have conclusively that the moon landing was a hoax, and they have sidebars to prove it! Their evidence comes from Bill Kaysing (the name sounds familiar... who is he, and did he ever really work at Rocketdyne?), who offers the following incontrovertible proof: 1) NASA has never released any photos in which the moon can be seen in relationship to planets other than Earth, because those relationships would be almost impossible to fake. Also, he says that the Earth in pictures from the Moon is too small. (I don't know, Kepler's laws don't seem too difficult to me...) 2) He says the LEM didn't kick up any dust, but that the astronauts' boots sink into the soil, and that the boots sink in more than the LEM footpads. (I'll have to analyze my tapes more; I always thought Buzz said "Picking up some dust" just before the alleged touchdown, but I must be mistaken...) 3) The information about the moon missions is not classified, but information is not available to the public. (So, I must have been hallucinating when I thought I was reading all the technical reports about the missions...) 4) The Apollo astronauts have stated that they don't want to discuss the missions. (True, Neil is happy to stay on his farm, and you don't see much of Buzz, but Mike Collins seems to me to be the kind of guy who'd be happy to talk about it all day. Not to mention Pete Conrad, Gene Cernan, Frank Borman, Alan Shepard, and John Young, all of whom seem talkative; then there's Tom Stafford, who I've talked to for several hours...) 5) The space suits the astronauts wore were not designed for the temperature extremes of the Moon. (So Rocketdyne built the suits too?) 6) The Van Allen belts should have "burned them to crisps." He points out that astronauts who merely orbit the Earth don't encounter them. (Wait... that means that some of the Gemini flights must have been faked too! This deserves further investigation!) Finally, my favorite: 7) There is a picture showing astronauts training on one of the lunar surface mock-ups, with a caption pointing out that girders can be seen in the picture. (The technical people really dropped the ball on this one, since they also forgot to put the gold foil on the LEM, and one of the astronauts has his sun visor up.) A couple other points are brought up, but these should be enough to convince anyone (under the age of six, anyway). I guess I need to modify my .sig... -------- jabishop@uokmax.ecn.uoknor.edu "I'm with you, LEM, though it's a shame that it had to be fake. The mother ship is just a set in which to do a take. I'm with you, boys, oh, there's something I just thought of. It's on my mind, we should be on the Moon, but we're in Nevada." --(Not Quite) Jethro Tull, "For Michael Collins, Jeffrey, and Me" ------------------------------ Date: 2 Mar 91 19:45:01 GMT From: crash!orbit!pnet51!schaper@nosc.mil (S Schaper) Subject: Re: Terraforming, ethics of human existance. Heidi, It sounds like you have a serious death wish. Get help. ************************************************************************** Zeitgeist Busters! UUCP: {crash tcnet}!orbit!pnet51!schaper INET: schaper@pnet51.orb.mn.org Aslan is on the move! **************************************************************************** ------------------------------ Date: 3 Mar 91 18:03:20 GMT From: att!cbnewsi!bicker@ucbvax.Berkeley.EDU (The Resource, Poet-Magician of Quality) Subject: I-CON X I - C O N X The East Coast's Largest Convention of Science Fact, Fiction, and Fantasy April 19-21, 1991 State University, Stony Brook, Long Island, NY Science Guest-of-Honor: Robert L. Forward Science and Technology Special Guest: Deke Slayton Mercury and Apollo Astronaut [Negotiating with a Russian cosmonaut as well.] [Full Science Track guest list available on request.] SciFi Track: Special Guest: Harlan Ellison Guest-of-Honor: Dan Simmons Author of the Hugo Award winning novel Hyperion [Full SciFi, Fantasy, Horror, Art, Comics, Trek, and Who guest lists available on request.] In addition to the personal appearances, panels and film program, I-CON features an Art Show, Meet the Pros Parties, dealers' rooms, writers' workshops, autograph party, no- minimum-bid auctions, gaming, filksinging, japanimation, model rocketry, gaming tournaments, sneak previews of upcoming films, videos, stargazing, ... Ticket Information: $20 until March 31, 1991 (Children 5-11 years old, $8). $25 at the door (Children 5-11 years old, $10). Children under 12 must be accompanied by a ticketholding adult at all times. I-CON P.O. Box 550 Stony Brook, NY 11790 For more information, send email to bicker@hoqax.ATT.COM. Please do not call...but if you call, at least leave a phone number so I can get back to you. -- Brian Charles Kohn AT&T Bell Laboratories Quality Process Center Quality Management System E-MAIL: att!hoqax!bicker (bicker@hoqax.ATT.COM) Consultant PHONE: (908) 949-5850 FAX: (908) 949-7724 ------------------------------ End of SPACE Digest V13 #225 *******************