Date: Tue, 27 Feb 1996 17:09:39 -0500From: David@interworld.com (David Levine) Organization: InterWorld,Really Cool Stuff Division Mime-Version: 1.0To: Kelly Starks x7066 MS 10-39 <kgstar@most.fw.hac.com> Cc:KellySt@aol.com, hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org,jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl,rddesign@wolfenet.com, bmansur@oc.edu, lparker@destin.gulfnet.comSubject: Nuclear Liquid Salt ReactorI don't remember if this has ever been discussed here, but I just saw thison sci.space.tech:-David=========================================================== >BTW I've just seen an old Zubrin proposal for a Nuclear Liquid SaltReactor. You take moderately enriched fuel in several tubes to a largertube where the uranium goes critical and passes out the back through anozzle. With a careful adjustment of the fuel flow there is a constantregion of criticality. Low radiation on the vessel because all the gunk is inthe fuel. He proposed it for LEO use. I liked it myself. Anyone seen aserious proposal for its use? No, but I can think of a few. Such a vehicle would be able to sustainmulti-G accelerations for days! Plus, the exhaust has a v(esc) higher thansolar escape v, so it's perfectly safe. Just don't tailgate! ===========================================================Date: Wed, 28 Feb 1996 11:16:21 -0500From: David@interworld.com (David Levine) Organization: InterWorld,Really Cool Stuff Division Mime-Version: 1.0To: Kelly Starks x7066 MS 10-39 <kgstar@most.fw.hac.com> Subject: Re:LITs down again?Kelly Starks x7066 MS 10-39 wrote:>I just tried to get to LIT to use the software and SUNSITE isn'tanswering. Grumble, grumble, grumble. If you have simple equations forcalculating spec impulse, fuel mass ratios and the like please pass themon. >Kelly>P.S.>Hi Dave. Hope things are going well. Sorry I only write (type?) when I'mticked off.Yea, I know, isn't it awful? They're down ALL the time. Well, here's theupdate on LIT - we're going to be switching over to Microsoft InternetServer, or whatever it's called, and everyone will have it on their desktopcomputer. It also includes FTP and Gopher. So when we do this (hopefullysoon), I'll have all three servers sitting here on my computer. Everyonewill have a directory to put stuff in, and things should be pretty cool. Inthe meantime we're stuck with SunSITE, though. Anyway, they recentlymoved SunSITE to an UltraSparc, which caused some problems whichthey're in the middle of fixing. Sorry, I don't have any formulas off-hand.David===========================================================Date: Wed, 28 Feb 1996 12:04:02 -0500From: David@interworld.com (David Levine) Organization: InterWorld,Really Cool Stuff Division Mime-Version: 1.0To: Kelly Starks x7066 MS 10-39 <kgstar@most.fw.hac.com> Subject: Re:LITs down again?>>Yea, I know, isn't it awful? They're down ALL the time. Well, here's theupdate on LIT - we're going to be switching over to Microsoft InternetServer, or whatever it's called, and everyone will have it on their desktopcomputer. >Have what on their desktop? It sounds like everyone in LIT will get ashadow site on their home system. (I'll definatly need to upgrade my Mac!;) )Oh, I meant everyone at InterWorld will have a WWW/FTP/Gopher server ontheir desktop. Most of us are running 120 Mhz Pentiums with Windows NT.The upshot of this is that since NT is a server-based mechanism with useraccounts, and so on, I can give everyone in LIT user accounts on mymachine (and directories). Then you guys can FTP stuff to and from theweb server which will run on my machine (and gopher server, if we decideto do that). I've done some basic testing on the one system we have so farthat does this: it's easy and works well.>Who is SunSITE? I presume they aren't a comercial firm. They'ld havegone out of busness by now.No, the space they give out is free, though they are specific about whatkinds of projects they give free space to. There have been a few articlesabout SunSITE in some recent web magazines. They've been on the Internetfor a long time and are known for trying to support artistic or otherwiseunusual internet projects that would normally have nowhere else to go. >You should be happy having direct control over the whole site. Well, I have a lot of control at SunSITE, but not over the computer onwhich it runs. Plus, it's a pain in the ass having to telnet over there tomake changes, esp. considering how much traffic they get - connectionsare slow. Having LIT on my computer at work will mean I'll be able to workon it -easily-, and often. >I've noticed we have attracked a bit of attention. I've been bouncingaround space groups and info sources in the web and LIT has been listed onmore than a few of them. We seem to be one of the few onlines listingthings like spec impulse software, and long range space projects. Interesting. I've seen occassional posts on Usenet listing a URL, usually toone of the pages like the Orion page or the Daedalus page.That Interstellar Propulsion Society (whatever it is) seems to get most ofthe real press, though.David===========================================================Date: Wed, 28 Feb 1996 12:48:34 -0500From: David@interworld.com (David Levine) Organization: InterWorld,Really Cool Stuff Division Mime-Version: 1.0To: Kelly Starks x7066 MS 10-39 <kgstar@most.fw.hac.com> Subject: Re:LITs down again?>>>I've noticed we have attracked a bit of attention. I've been bouncingaround space groups and info sources in the web and LIT has been listed onmore than a few of them. We seem to be one of the few onlines listingthings like spec impulse software, and long range space projects. >>Interesting. I've seen occassional posts on Usenet listing a URL, usuallyto one of the pages like the Orion page or the Daedalus page.>>That Interstellar Propulsion Society (whatever it is) seems to get mostof the real press, though.>>David>Never heard of the "Interstellar Propulsion Society". If you have themnear at hand send me the URL's for them and the Daedalus page. Maybe theyhave some specific impulse numbers for fusion system. Best I've seen is Oh, when I said that I saw mentions of the Orion and Daedalus pages onUsenet, I was talking about LIT's pages... I was just commenting on thesame "noticing" that you were talking about. The Interstellar PropulsionSociety doesn't have ANY technical information on their site (last time Ichecked), just a lot of big names. When LIT passed it's one yearanniversary, IPS had just gotten their web site and were getting publicity.I even put a note in the newsletter ("Take THAT, IPS"). http://www.tyrian.com/IPS/is their homepageForward, Matloff, and Zubrin are all on the Board. They charge formembership. The site is mainly an advertisement. And they get a lot morepress than we do, even though WE'RE the ones doing something. I'm SOannoyed.DavidX-Sender: kgstar@pophost.fw.hac.comMime-Version: 1.0================================================================Date: Fri, 1 Mar 1996 12:22:18 -0500To: Kevin C Houston <hous0042@maroon.tc.umn.edu>From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39)Subject: Re: tentative hybrid design.Cc: interstellar drive group <bmansur@oc.edu>, David@interworld.com,jim@bogie2.bio.purdue.edu, KellySt@aol.com, kgstar@most.fw.hac.com,lparker@destin.gulfnet.com, rddesign@wolfenet.com, Steve VanDevender<stevev@efn.org>, T.L.G.vanderLinden@student.utwente.nl,zkulpa@zmit1.ippt.gov.plBcc: X-Attachments: At 10:52 AM 3/1/96, Kevin C Houston wrote: >Kevin sees Brian's "pocket change" and rasies one dollar. ;) >I don't have much time right now, so this will be short. >Here's the idea I'm thinking of.>the ship starts off as a hybrid structure. a MARS-like front end, with anexplorer-like backend.>the ship accelerates out of Sol System with a simple maser sail. Thelarge fuel tanks (used by the MArs as RM, but used by explorer like fuel) onthe MARS keep us shielded from interstellar speed-induced radiation. Aswe approach the halfway point, (speed ~ .9905 C) the two ships separate.the MARS begins converting the masers to electricity, cutting it's photonderived thrust to ~5 m/s^2 (1/2 G) under computer control, the fuel isthrust out the back end so that it's speed is just under the MARS'svelocity. The velocity of the and mass of the exhaust can be tailored to theneeds of the explorer, since there will be no humans aboard the MARSGiven that the Explorer will be slowing down, and the Mars accelerating,this would have the fuel raceing ahead of the ship at up to near lightspeeds. Even if you could kill the fuel speed you'ld have accuracy problems.The ships wouldn't have time to separte much more than a half light year,but the fuel could spend a long time drifting between. Plus of course thiswould be a tremendous amount of fuel to carry. I'm not sure you couldcarry that much fuel? Might be better to put a Mini mars microwave sail on the droped ship andhave the main ship transmit power to it. >Meanwhile, the explorer spreads a large ram scoop out *behind* itself.This scoop grabs the (already) ionized fuel, (no containers, just gas) andfuses it, redirecting the exhaust at the retreating MARS. The redirectedexhaust protects the crew sections from erosion by the fuel. Neat trick. How does the explorer catch fuel behind it and fire the exaustahead of it? Be simpler to make the frount end a combined scoop-motor-shield. The scop would funnel anything it caught into the bowel shapedreaction chanber shield. The high drag (if you slow the fuel down a lot),compresion/fusion drage, and reverse thrust could get a lot deceleration. >The MARS continues along toward TC, getting closer and closer to thespeed of light. just before it enters Tau Ceti itself, hundreds of smallprobes luanch away (at perpendicular velocities) get some slight bendingfrom the star, and streak away to fly-by various other stars. The big tanks(now empty) and the lineac core crash straight into the star, and makenary a splash.At near light speed? Wouldn't it at least cause a flare? The probes wouldn't have any course change near the star. Their velocitywould be too high (near light speed), but the mars would be a hell of a goodlong range observatory. Oh, I forgot about optical distortion due to speed. >The crew deploys self-replicating robots (under some human direction) toconstruct the return masers, and a simple manufacturing plant handles thereturn sail (much like chicken wire) the explorer, after ditching it's fusionmotor, sails off back toward Sol, where the original masers sit waitingfor our return. :)>KevinI'ld really think that having the first stage Mars retransmit a microwavebeam back to the drop ship would solve a lot of your problems, and lightenthe ship mass. Kelly============================================================