Date: Mon, 8 Feb 93 07:18:37 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #130 To: Space Digest Readers Precedence: bulk Space Digest Mon, 8 Feb 93 Volume 16 : Issue 130 Today's Topics: DC reentry galileo update? Getting people into Space Program! HELP!!! Help on catching this Real work/Research/Jobs Priorities Remotr Control in Space Retaining Goldin Russian Solar Sail/Media Attention So what's happened to Henry Spencer? Space Grown Semiconductors (2 msgs) Supporting private space activities Temperature of space well.. (2 msgs) Welcome to the Space Digest!! Please send your messages to "space@isu.isunet.edu", and (un)subscription requests of the form "Subscribe Space " to one of these addresses: listserv@uga (BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle (THENET), or space-REQUEST@isu.isunet.edu (Internet). ---------------------------------------------------------------------- Date: Thu, 4 Feb 1993 01:16:50 GMT From: Henry Spencer Subject: DC reentry Newsgroups: sci.space In article <1j713pINNf8q@mirror.digex.com> prb@access.digex.com (Pat) writes: >... the nose first trajectory conserves >fuel, which seems to be the current tight spot in DC-Y. if they >still have a 10,000 lb margin after construction, then maybe >they will skip the flip over. Unlikely... if only because the flip is, to some extent, McDonnell-Douglas technology that they can claim proprietary rights to. (There have been allegations that this is the real reason why the DC design is set up for nose-first reentry -- because base-first with an aerospike offers McDD nothing to call its own.) -- "God willing... we shall return." | Henry Spencer @ U of Toronto Zoology -Gene Cernan, the Moon, Dec 1972 | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 3 Feb 93 19:02:01 EST From: richard attenborough Subject: galileo update? Newsgroups: sci.space RB>In article <1993Jan27.133908.16401#prime.mdata.fi>, jarnis@mits.mdata.fi (Jarno Kokko) writes... RB>>Have people thought about combining hammering with the orbit insertion? RB>>I think hammering when whole spacecraft is vibrating due to motor RB>>firing would shake loose about anything :-) .. Or is it impossible RB>>due to some minor technical detail? RB> RB>I don't think that would be a wise thing to do. The motor firing has be RB>done at a precise time with the spacecraft in the proper attitude. If the RB>hammering was done during the motor firing, and the antenna was to pop RB>open, it could change the spacecraft attitude enough to really mess up the RB>orbit insertion. Besides, the spacecraft will very busy as it is during RB>the orbit insertion, collecting the probe data, performing a 1000 km Io flyby RB>and collecting science data on Jupiter. Some time ago, Ron, you mentioned that the release of the atmosphere probe might provide a nice "kick" to the system, releasing the ribs. Has any further study of this possibility been done? -Richard Attenborough- Canada Remote Systems - Toronto,Ontario,Canada,North America,Earth........ or Durham Board of Education BBS (416)-666-4896 V.32bis Fidonet 1:229/116 - Whitby,Ontario,Canada ....(you get the picture &->) * KingQWK 1.05 * That was Zen, this is Tao... -- Canada Remote Systems - Toronto, Ontario World's Largest PCBOARD System - 416-629-7000/629-7044 ------------------------------ Date: Wed, 3 Feb 1993 23:28:51 GMT From: nsmca@acad3.alaska.edu Subject: Getting people into Space Program! Newsgroups: sci.space It seems that we are putting more in to our Space Program more than is necesary.. Why can't we put some "common people" into orbit.. Why must it be PHds and such. It sure would get more voters involved, after all why must I as a voter spend money on a project for the direct benefit for some technocrat? Why not have a national lottery for a one time position on the Shuttle or some other mission into space.. Common people do not get excited about abstract things, but get excited about tangible things.. If I was working for a NASA contractor, I might get excited more about space. But if Im a autoworker, what does space benefit me/and my job, none directly... We need to get the space program down to the common person so that they can understand where it is going and what benefits there is to it.. == Michael Adams, nsmca@acad3.alaska.edu -- I'm not high, just jacked ------------------------------ Date: 4 Feb 1993 00:00:56 GMT From: Jeff Bytof Subject: HELP!!! Newsgroups: sci.space In article <1993Feb3.102458.1@woods.ulowell.edu> cotera@woods.ulowell.edu writes: >From: cotera@woods.ulowell.edu >Hey, does anyone know the rest mass of the universe and its radius? I need to >check out a theory. >--Ray Cote estimate for mass of universe = 1 solar mass * 10^11 stars in galaxy * 10^11 galaxies = 10^22 solar masses estimate for radius of universe = 10^10 light years -rabjab ------------------------------ Date: Thu, 4 Feb 1993 03:29:18 GMT From: Bruce Dunn Subject: Help on catching this Newsgroups: sci.space In article rbatra@uceng.uc.edu (Rajesh Batra) writes: > Hi, > > Here's a problem that I'm just plain stuck on, see if you can help. > > Scenerio: You're on the moon, a 1700 m/s container (containing ice) which > weighs approximately 120 kg is hurled at you. How do you catch it such > that you can salvage the ice? You have free reign over the container- > hence the size/material. Do a "resal hcnual" -- laser launch backwards :-) Vaporize a portion of the incoming ice with a laser, creating a thrust which deaccelerates the payload. This is trivial compared with laser launching from the earth to low earth orbit. Only a fraction of the delta V is needed, and there is no atmosphere to screw up the beam. You may have to put the laser on a high hill however to overcome the problem of the short distance to the lunar horizon. -- Bruce Dunn Vancouver, Canada Bruce_Dunn@mindlink.bc.ca ------------------------------ Date: 3 Feb 93 23:19:41 GMT From: nsmca@acad3.alaska.edu Subject: Real work/Research/Jobs Priorities Newsgroups: sci.space Interesting thought, are we working on a space program for "real work", "Research" or for "jobs"... We must decide what our priorities are.. == Michael Adams alias Ghost Wheel/Morgoth NSMCA@acad2.alaska.edu ------------------------------ Date: 3 Feb 93 23:12:51 GMT From: nsmca@acad3.alaska.edu Subject: Remotr Control in Space Newsgroups: sci.space I might have missed something. Is there a project in hand to start doing remote control experiments in space.. Namely to see if/how a future mission to Mars and whereever can remotely control slave units.. Such as like if Mir was remotely controlling Znamya versus having the ground base doing it.. == Michael Adams, nsmca@acad3.alaska.edu -- I'm not high, just jacked ------------------------------ Date: Thu, 4 Feb 1993 01:11:23 GMT From: Henry Spencer Subject: Retaining Goldin Newsgroups: sci.space In article KitchenRN@ssd0.laafb.af.mil writes: >As someone who seems to have come in on this thread in the middle of the >discussion, could someone please explain to me what is wrong with replacing >Administrator Goldin with someone of President-elect Clinton's choosing? Goldin is doing something extremely rare for a man in such a bureaucratic position: he is making serious noises about reform, and even starting to act on them. Given how badly NASA needs reforming, replacing him with a political hack like Bill Nelson would be an awful mistake. Could you please explain to us why Goldin *needs* replacing? He has credible technical background, credible management background, and real interest in the job -- that alone is a rare combination -- and the only thing anyone can find against him seems to be that he was appointed to it by the wrong man. Oh yes, and that he's upsetting some applecarts that some fat contractors would rather stayed upright. Goldin is, by the way, a Democrat. -- "God willing... we shall return." | Henry Spencer @ U of Toronto Zoology -Gene Cernan, the Moon, Dec 1972 | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 3 Feb 93 23:08:45 GMT From: nsmca@acad3.alaska.edu Subject: Russian Solar Sail/Media Attention Newsgroups: sci.space If the Russian Zemsya project is a "solar sail' then why does CNN says its a mirror. The "lighting the arctic" line is or looks like lunacy to many people, why not say what it is also.. Yes a mirror but also a Soalr Sail design project.. and go into what a solar sail is.. One of the problems I see with the Space Program for the US and the world, is the way the media portrays the space programs.. == Michael Adams, nsmca@acad3.alaska.edu -- I'm not high, just jacked ------------------------------ Date: Thu, 4 Feb 1993 00:55:47 GMT From: Paul Dietz Subject: So what's happened to Henry Spencer? Newsgroups: sci.space In article henry@zoo.toronto.edu (Henry Spencer) writes: > history of his single-stage-to-orbit concepts, and Mitchell Burnside > Clapp tell you why kerosene and hydrogen peroxide is a better fuel > combination for an SSTO than LOX/LH2? I'd like to here more about that. I assume the much higher density (5-6 times?) of the kerosene/peroxide combination more than compensates for the lower Isp, so that smaller and lighter tanks can be used (and that having room-temperature storable propellants makes the tanks easier to build and pressurize.) But do you need more or larger engines to get enough thrust, for a given size payload, and can peroxide be pumped safely? Paul F. Dietz dietz@cs.rochester.edu ------------------------------ Date: 3 Feb 93 18:35:18 From: Steinn Sigurdsson Subject: Space Grown Semiconductors Newsgroups: sci.space See Nature, _360_ 293-294 26 Nov 1992 for a summary review + references | Steinn Sigurdsson |I saw two shooting stars last night | | Lick Observatory |I wished on them but they were only satellites | | steinly@lick.ucsc.edu |Is it wrong to wish on space hardware? | | "standard disclaimer" |I wish, I wish, I wish you'd care - B.B. 1983 | ------------------------------ Date: Thu, 4 Feb 1993 04:10:51 GMT From: gawne@stsci.edu Subject: Space Grown Semiconductors Newsgroups: sci.space,sci.materials In article , steinly@topaz.ucsc.edu (Steinn Sigurdsson) writes: [refering to space grown semiconductors] > See Nature, _360_ 293-294 26 Nov 1992 for a summary review + references OK, I tried that and discovered what I suspect most others will. The Nov 92 issues are currently "at the bindry" for binding. Lovely. I can't get anything that was published between July 92 and Dec 92 it would seem. So, Steinn, if you have a spare few minutes might you post a brief review of what the Nature article had to say? -Bill Gawne, Space Telescope Science Institute ------------------------------ Date: Thu, 4 Feb 1993 01:51:22 GMT From: Henry Spencer Subject: Supporting private space activities Newsgroups: sci.space In article <73694@cup.portal.com> BrianT@cup.portal.com (Brian Stuart Thorn) writes: >>...the only really technical reasons for Florida (the weather is lousy). > > Don't blame Florida because NASA chose to launch Challenger on > the coldest day of the year. Don't blame Florida because NASA > launched at Atlas-Centaur into a thunderhead (ignoring the > near disaster of Apollo 12). Florida weather is no worse than > anywhere else... The problem with Florida weather is not that it's worse than anywhere else -- although you can make a case for this, it's not an accident that KSC gets used by people doing lightning research -- but that it is very hard to predict very far in advance. The advantage of landing the shuttle at Edwards is not that Edwards's weather is better (although it is) but that an Edwards weather prediction is fairly reliable. KSC not only gets lots of thunderstorms, it gets lot of *surprise* thunderstorms, including some that go from "chance of a thunderstorm today" to "major thunderstorm" in the time from de-orbit burn to landing. Ever wondered why they always roll the shuttle out to the pad in the wee small hours of the morning? It's because the chances of a surprise thunderstorm are lowest then. For the Saturn V this didn't matter, because it had an umbilical tower on the mobile pad to carry a lightning rod, but that tower got removed for the shuttle program. The orbiter has no lightning protection between the VAB and the pad, so they worry about the weather during a rollout. (By contrast, the first Saturn V rolled out to the pad in weather so bad that they had to stop for 20 minutes or so because the visibility was too poor for safe driving.) -- "God willing... we shall return." | Henry Spencer @ U of Toronto Zoology -Gene Cernan, the Moon, Dec 1972 | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Thu, 4 Feb 1993 01:32:33 GMT From: Henry Spencer Subject: Temperature of space Newsgroups: sci.space In article 18084TM@msu.edu (Tom) writes: >-Second thing that I've been thinking about... What's the average >-temperature of space (just "empty" space, not including planets, etc)? > >For purposes of radiating heat into space, it is treated as a 3K sink, >since that's the temperature of the microwave background radiation. A common misconception. Yes, that is the temperature of the microwave background, but there are also things like stars, the zodiacal light, etc. that are brighter than the background. The average temperature of "black" sky at roughly Earth's distance from the Sun is something like 25K, not 3K. >I don't know if the temerature of interstellar (or intrplanetary) >gas adds a significant amount. Presumably, since it's been there >for a really long time, it has already reached equilibrium with the >background. Not really. Interplanetary gas is the solar wind, expelled relatively recently from the Sun's atmosphere (if you want to be technical, it *is* the Sun's atmosphere), and by no means at equilibrium with the dark-sky background; in fact it's very hot. Even interstellar gas is more dynamic than you might think, and in fact the solar system is thought to be within an unusually thin, unusually hot bubble of interstellar gas thrown off by a recent nearby supernova. (We know the average properties of interstellar gas fairly well from long-range observations, but if the nearby gas wasn't thin and hot, the Extreme UltraViolet Explorer would be nearly blind because of absorption by cool hydrogen... and it's not.) -- "God willing... we shall return." | Henry Spencer @ U of Toronto Zoology -Gene Cernan, the Moon, Dec 1972 | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 3 Feb 1993 16:47 PST From: "FRED W. BACH" Subject: Well.. Newsgroups: sci.space,sci.misc,rec.arts.startrek.tech In article , bbs.maddox@gilligan.tsoft.net (Otto Maddox) writes... # How long would it take a ship traveling at Warp 1 to get to a #planet that is 60 light years away? # # I have a an answer in my head but I wanna see if I am doing this #thing #right. # # #Otto Maddox #[ bbs.maddox@tsoft.net ] [ maddox@west.darkside.com ] If WARP 1 is the speed of light, then in one year (by outside observer measurements) the ship travels 1 light-year. It would take the space ship 60 years to travel 60 light-years at warp 1. Fred W. Bach , Operations Group | Internet: music@erich.triumf.ca TRIUMF (TRI-University Meson Facility) | Voice: 604-222-1047 loc 327/278 4004 WESBROOK MALL, UBC CAMPUS | FAX: 604-222-1074 University of British Columbia, Vancouver, B.C., CANADA V6T 2A3 These are my opinions, which should ONLY make you read, think, and question. They do NOT necessarily reflect the views of my employer or fellow workers. ------------------------------ Date: 3 Feb 93 23:43:01 EST From: mike knox Subject: well.. Newsgroups: sci.space In Message-ID: , bbs.maddox@gilligan.tsoft.net (Otto Maddox) writes: > How long would it take a ship traveling at Warp 1 to get to a >planet that is 60 light years away? Since "warp" is a science fiction term from Star Trek, the answer has to be given in those terms. In Star Trek, Warp 1 is defined as 1.24 x C and goes all the way up to the theoretical maximum of Warp 10 which is an incredible 523,171.18 x C. Star Trek also assumes a "relativistic time dilation" of 64.6% which remains constant inside of the warp field effect regardless of superluminal speed. Therefore, the answer to your question is: (60 / 1.24) x 0.646 = 48 years. (At Warp 5 it would take only about 5 1/2 days.) --------------------------------------------------------------------------- Mike Knox | Fido: 1:229/15 Brampton, Ontario | Internet: mike.knox@canrem.com CANADA | RelayNet: ->CRS (Public Key: 22319) --------------------------------------------------------------------------- --- DeLuxe/386 1.25 #4782 -- Canada Remote Systems - Toronto, Ontario World's Largest PCBOARD System - 416-629-7000/629-7044 ------------------------------ Received: from crabapple.srv.cs.cmu.edu by VACATION.VENARI.CS.CMU.EDU id aa02532; 4 Feb 93 3:40:40 EST To: bb-sci-space@CRABAPPLE.SRV.CS.CMU.EDU Newsgroups: sci.space Path: crabapple.srv.cs.cmu.edu!bb3.andrew.cmu.edu!news.sei.cmu.edu!cis.ohio-state.edu!zaphod.mps.ohio-state.edu!uunet.ca!canrem!dosgate!dosgate![richard.attenborough@canrem.com] From: richard attenborough Subject: biosphere 2 oxygen Message-Id: <1993Feb3.4287.601@dosgate> Reply-To: richard attenborough Organization: Canada Remote Systems Distribution: sci Date: 3 Feb 93 19:02:00 EST Lines: 20 Sender: news@CRABAPPLE.SRV.CS.CMU.EDU Source-Info: Sender is really isu@VACATION.VENARI.CS.CMU.EDU Taber, RE: Oxygen levels dropping. Have you considered the possibility of fungal growths taking place? These growths MIGHT bind up Oxygen in their mass. If the original soil was sterilized then the fungii would have an open environment for breeding. They would spread throughout the soil. This is probably NOT what is happening, but felt it couldn't hurt to suggest it. -Richard Attenborough- Canada Remote Systems - Toronto,Ontario,Canada,North America,Earth........ or Durham Board of Education BBS (416)-666-4896 V.32bis Fidonet 1:229/116 - Whitby,Ontario,Canada ....(you get the picture &->) * KingQWK 1.05 * If we don't succeed, we run the risk of failure -- Canada Remote Systems - Toronto, Ontario World's Largest PCBOARD System - 416-629-7000/629-7044 ------------------------------ End of Space Digest Volume 16 : Issue 130 ------------------------------