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 ; Mon, 25 Feb 91 01:39:01 -0500 (EST) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Mon, 25 Feb 91 01:38:55 -0500 (EST) Subject: SPACE Digest V13 #200 SPACE Digest Volume 13 : Issue 200 Today's Topics: Re: Terraforming, sun shield NASA technology choices Re: Japan's Space Industry Re: Terraforming Venus Re: Terraforming, sun shield Re: Government vs. Commercial R&D Re: "Face" on Mars Re: Terraforming, sun shield Re: Manoeuvring using rope and anchor(was: Solar Impact Mission.) Re: Confusion regarding "Firm Fred Decisions" 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: 24 Feb 91 20:17:57 GMT From: zaphod.mps.ohio-state.edu!usc!cs.utexas.edu!news-server.csri.toronto.edu!qucdn!gilla@tut.cis.ohio-state.edu (Arnold G. Gill) Subject: Re: Terraforming, sun shield In article <1991Feb22.211048.29599@zoo.toronto.edu>, henry@zoo.toronto.edu (Henry Spencer) says: >I saw a paper in JBIS proposing impacts by the largest half-dozen asteroids, >to simultaneously blast off a fair bit of the atmosphere and spin up the >planet (its rotation is annoyingly slow). My dim recollection is that the >blast-off scheme does not, in fact, work as well as the authors proposed. >It's really hard to get rid of 90atm of gas around an Earth-sized planet. Well, then, do what happened to the Earth -- get a bigger planetoid. The big Earth impact was supposed to be Mars-sized -- you might even get a moon for Venus out of it. If we are terraforming Venus, do we need Mars for anything anymore? :-) -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- | Arnold Gill | - If I hadn't wanted it heard, | | Queen's University at Kingston | I wouldn't have said it. | | InterNet: gilla@qucdn.queensu.ca | - Astrophysician in training | -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- ------------------------------ Date: 23 Feb 91 22:13:55 GMT From: zaphod.mps.ohio-state.edu!unix.cis.pitt.edu!pitt!nss!Paul.Blase@handies.ucar.edu (Paul Blase) Subject: NASA technology choices Philosophical question of the week. I recently watched 2001: A Space Odessey again. I rather like the EVA pods that astronauts used to repair the Discovery. One of the recent 'problems' discovered with Space Station Freedom is that the number of hours of EVA required to repair the station was unacceptably high. Thusly, NASA is spending gobs of money on telefactor and robotic widgetry so that the astronauts don't have to leave the station. Why doesn't NASA develop a space pod like those used in 2001? It would almost have to be cheaper and less risky (from an R&D point of view). Any thoughts? --- via Silver Xpress V2.26 [NR] -- Paul Blase - via FidoNet node 1:129/104 UUCP: ...!pitt!nss!Paul.Blase INTERNET: Paul.Blase@nss.FIDONET.ORG ------------------------------ Date: 24 Feb 91 18:47:00 GMT From: prism!ccoprmd@gatech.edu (Matthew DeLuca) Subject: Re: Japan's Space Industry In article <217.27C3A53D@nss.FIDONET.ORG> Paul.Blase@nss.FIDONET.ORG (Paul Blase) writes: >WRONG!!! The Japanese ARE spending serious money on the subject. They >intend to MAKE A PROFIT!!!!!!!!! (at our expense). How do they plan to do it at *our* expense? If they have sense enough to go where the profits are, good for them. Hopefully we'll do the same. -- Matthew DeLuca Georgia Institute of Technology Do not meddle in the affairs of wizards, Office of Information Technology for they are subtle, and quick to anger. Internet: ccoprmd@prism.gatech.edu ------------------------------ Date: Sun, 24 Feb 91 18:16:38 EST From: John Roberts Disclaimer: Opinions expressed are those of the sender and do not reflect NIST policy or agreement. Subject: Re: Terraforming Venus In the discussion on terraforming Venus, an important item should be taken into account: Venus is one of the very worst places in the solar system to prepare for large-scale human habitation. (Others include Jupiter and the sun.) It's interesting to discuss it in a purely speculative sense, as we might discuss the best way to populate the earth's core, but with almost any conceivable developments in technology we could populate Mars, the moon, the asteroids, some of Jupiter's moons, nearby star systems, and interplanetary space, all with far less time and trouble than it would take to deal with Venus. If anybody comes up with a way to easily and precisely manipulate planetary masses (much larger scale than just running comets into planets), then I'll be willing to reconsider. :-) I can dig up some numbers if anybody wants them. John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: 24 Feb 91 03:05:02 GMT From: timbuk!cs.umn.edu!kksys!orbit!pnet51!jduffin@uunet.uu.net (Joshua Duffin) Subject: Re: Terraforming, sun shield Just an idea, but as long as we're going to get water from asteroids, how about if we just send a real big one (err, make that comet I think, asteroids are more rocky than icy...) into Venus, to kick up a nice cloud of dust to cool off the planet at the same time as we add water? Save on energy to decelerate the comet, too. UUCP: {amdahl!bungia, crash}!orbit!pnet51!jduffin ARPA: crash!orbit!pnet51!jduffin@nosc.mil INET: jduffin@pnet51.orb.mn.org ------------------------------ Date: 25 Feb 91 02:57:25 GMT From: zephyr.ens.tek.com!tektronix!sequent!crg5!szabo@uunet.uu.net (Nick Szabo) Subject: Re: Government vs. Commercial R&D In article <1991Feb24.022403.19769@ux1.cso.uiuc.edu> bryans@ux1.cso.uiuc.edu (B. Charles Siegfried) writes: [I posted patent statistics and analysis of major inventions] >....Pure research will not result in immediate patents, >and because of this, private firms are less likely to support >research in these areas. I agree. This topic came about, however, because the argument was put forth that (a) important applied science and engineering advances require large projects, (b) the private industry won't fund these, therefore (c) the government should undertake these projects. Analysis of important 20th century inventions showed (a) to be false; in fact most breakthroughs were produced by a small number of people with small amounts of money. Seeing how you feel about the human genome project, I guess you would agree this is also true for pure research. Analysis of patents in general showed that (b) is false; the overwhelming majority of patents come from private industry. Therefore, (c) is surely a bad direction to go for most applied science and engineering R&D. Since private industry engages in very little pure research or exploration, it is desirable for these to be government funded. >... Although I don't support the government giving >large grants to stimulate certain areas of research (such as the >human genome fiasco), it should support the universities enough to >provide the large amount of pure research that an growing economy >needs. I also agree wholeheartedly with this. Government support of university projects is shown by history to be the best way to promote both basic scientific research and exploration. The university also has a role in applied research, as many applied science and engineering breakthroughs come from corporate/university teams. -- Nick Szabo szabo@sequent.com Think long-term, act now. ------------------------------ Date: Sun, 24 Feb 91 17:37:58 EST From: John Roberts Disclaimer: Opinions expressed are those of the sender and do not reflect NIST policy or agreement. Subject: Re: "Face" on Mars >From: pflueger@thewav.enet.dec.com (Free speech is a sound investment) >Subject: Background on the Monuments of Mars (was re: Martian mystery?) >Organization: Digital Equipment Corporation >If your interested in more background about this subject, you might pick up a >copy of "The Monuments of Mars" by Richard Hoagland. I read it last summer and >found it to be quite interesting. > Jim Pflueger | pflueger@thewav.enet.dec.com > DEC Enterprise Integration Services| !decwrl!thewav.enet!pflueger > Costa Mesa, California | "Take Kuwait Back! - Go Troops!" Unfortunately, if you buy such a book, it rewards the author (by royalties) whether or not his theory makes the slightest sense - so just being sensational is not valid justification for purchasing a book. (Though with the current literary climate, one could probably write a book arguing that the "Face" was carved by Julius Caesar in the year 100000 BC, and make money off it.) I wonder what those people who wrote "The Jupiter Effect" did with all the money they made? (I know, they must have shamefacedly bought all the books back when their theory didn't pan out! ;-) Anybody have a copy? Disclaimer: just opinions... John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: 23 Feb 91 20:35:07 GMT From: borg!vangogh!leech@mcnc.org (Jonathan Leech) Subject: Re: Terraforming, sun shield In article <1991Feb22.220822.16590@helios.physics.utoronto.ca>, hall@aurora.physics.utoronto.ca (Chris Hall) writes: |> We need to put it where the Earth put it's atmosphere; in limestone. |> That's what the critters are good for. Now the trick would be to get |> carbonate fixing micro-organisms to settle onto the surface without |> re-releasing the CO2. At the present surface temperatures of Venus, |> this might be tricky. Maybe this is where a sun shield could come in |> handy? Hmmmmmmm I dug out my copy of Oberg's _New Earths_ (Stackpole 1981; ISBN 0-8117-1007-6) just now. The approach he advocates is a little different from what we've been talking about: rather than removing the atmosphere mechanically or binding it to rock, he wants to import H2 from Saturn to turn it into water. Quoting from the summary of the chapter on Venus: "...The most attractive targets in the stifling Venusian ``greenhouse effect'' are the trace components which block important ``windows'' for the escape of heat (since CO2 by itself does not produce a particularly powerful ``greenhouse effect''). These are SO2 and H20; both can be attacked either biologically or chemically. "...The time scale for the surface rocks to cool to habitable levels, even under the best conditions, would be measured in centuries. "...But once the free oxygen is released, the problem is only half-solved since there still would be several hundred times too much oxygen...Some of that oxygen may be absorbed by surface rocks, but without substantial erosion [earlier Oberg claims the mass of rock needed is equivalent to a 100 km deep layer covering the planet - Jon], the rocks will not be able to handle more than a tiny fraction of this oxygen. A good way to eliminate this oxygen would be to import vast qunatities of hydrogen from the atmospheres of the outer planets, a tactic which would convert the unwanted oxygen into badly needed water" End of quote. Despite the mass of H2 needed from Saturn being much smaller than the mass of CO2 to remove from Venus, I suspect it would be a far more difficult task than removing the Venusian atmosphere - we would have to actually capture and transport the gas down the gravity well in some sort of containers. -- Jon Leech (leech@cs.unc.edu) __@/ UNDERWHELMING OFFER OF THE MONTH: "Please feel free to skip the payment on this month's statement. Normal finance charges will apply." - NCNB VISA ------------------------------ Date: 19 Feb 91 17:33:23 GMT From: zaphod.mps.ohio-state.edu!unix.cis.pitt.edu!pitt!nss!Paul.Blase@handies.ucar.edu (Paul Blase) Subject: Re: Manoeuvring using rope and anchor(was: Solar Impact Mission.) JJ> Would it be technically possible to extend the idea of dipping JJ> into the atmosphere by throwing an anchor out to a planet and JJ> swinging around it? What I'm thinking of is, say, a 10Km Kevlar JJ> (or Twaron, for us Dutch:-) cable with something like an anchor JJ> at the end, have the anchor impact a reasonably sized asteroid JJ> (a couple Km diameter, enough orders of magnitude difference in JJ> mass that you don't accidentally send the asteroid somewhere JJ> you don't want it to be), and release anchor and cable once JJ> you're facing the direction you want to go? A slightly different variation: don't anchor the end of the cable, put an extendable drag anchor on it and use it for aeromanuvering(?). That way you would get a gradual increase in acceleration. Have you heard of the 'rotovator' proposed several years ago (I forget the exact source, but I can find it - it is mentioned in the Dr. Forward reports that I posted summaries of a while back). The Rotovator is a variation on the beanstalk; instead of one end of the cable anchored to the ground, both ends rotate around the center of gravity. The length of the cable and the rotation are such that as each end of the cable reaches its closest approach to the planet (or Luna) it is standing still relative to the ground (for a few seconds). The other end, of course, is traveling at a high rate of speed in the other direction, several hundred kilometers away vertically. You latch your space pod onto the end of the cable as it is standing still near the surface and hang on. The rotation of the cable (similar to that of a giant wheel rolling around the planet) lifts you off. When you reach the other side, at maximum distance from the planet, you let go. The advantage of this (as illustrated in Forward's paper, is that it can be built with available technology, such as Kevlar (the tensile strength required is less than that required for a beanstalk). --- via Silver Xpress V2.26 [NR] -- Paul Blase - via FidoNet node 1:129/104 UUCP: ...!pitt!nss!Paul.Blase INTERNET: Paul.Blase@nss.FIDONET.ORG ------------------------------ Date: Sun, 24 Feb 91 15:47:36 -0500 From: "Allen W. Sherzer" Subject: Re: Confusion regarding "Firm Fred Decisions" Newsgroups: sci.space Cc: In article <9363@hub.ucsb.edu> Charles Radley writes: + However, you focus at length on the problems of cutting +openings, not of putting airlocks in them. 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. With appropriate seals it should do. When I scuba dive my life always depends on the integrity of several bolted interfaces. Ditto for other undersea applications like subs and underwater dive platforms for oil drilling. They need to keep integrity for years at a time and at pressures far greater than in space. You need to pick your materials differently but I'm sure it is possible. > Interesting. Please tell us how they plan to install an airlock. I refer you to the External Tank Study published by the Space Studies Institute (subtle advertizement: these guys do great work; send them lots of your money). Martin has designed a structure called the Aft Cargo Carrier (ACC) which connects to the bottom of the ET. It is designed to add cargo space and one variant of it is an ET based space station. The ACC has an airlock built into it. The crew can transfer to it via EVA and have a shirt sleve environment in which to furnish the inside of the ET. >Windows would be nice too. But not a necessity. However, the ACC does have windows. >Which of them volunteered >to be the first one to go through the airlock without a suit on ? If it comes to that, I'll do it. > Sorry, you just failed the leak test. Start again. Assuming that is in fact what happens, no problem. This approach is so cheap that we just redo the airlock and use the next ET instead. > Nobody has ever installed a kluge fit airlock in orbit, not >even the Soviets want to be the first to take that risk. The Soviets have installed kluge airlocks on the ground. They also do kluge's in space. Allen -- +-----------------------------------------------------------------------------+ |Allen Sherzer |A MESSAGE FROM THE ANTI-WAR MOVEMENT TO THE PEOPLE OF KUWAIT: | |aws@iti.org | "If rape is inevitable, enjoy it!" | +-----------------------------------------------------------------------------+ -- +-----------------------------------------------------------------------------+ |Allen Sherzer |A MESSAGE FROM THE ANTI-WAR MOVEMENT TO THE PEOPLE OF KUWAIT: | |aws@iti.org | "If rape is inevitable, enjoy it!" | +-----------------------------------------------------------------------------+ ------------------------------ End of SPACE Digest V13 #200 *******************