Date: Tue, 30 Mar 93 05:49:28 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #389 To: Space Digest Readers Precedence: bulk Space Digest Tue, 30 Mar 93 Volume 16 : Issue 389 Today's Topics: Acceptable metric conversions (was Re: Pioneer Venus Last Findings) (2 msgs) Alaska Pipeline and space exploration/usage. Aluminum, James Burke, and The Lost Secrets of the Ancients... Breathing 100 atm. of anything Budget Astronaut (was: Idle Question) Commercial point of view Coral and Dyson Sphere.. DC-X: Vehicle Nears Flight Test Gemini 8 (was Re: Artificial Gravity) Jules Verne Gun KRYSTAL in separate orbit? Metric conversion sheet request!! More water simulations nuclear waste Terraforming Venus the call to space (was Re: Clueless Szaboisms ) US Satellite Crashing on Brisbane?? Why is Venus so bad? 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: Tue, 30 Mar 93 05:39:57 GMT From: Mark Brader Subject: Acceptable metric conversions (was Re: Pioneer Venus Last Findings) Newsgroups: sci.space > > ... between 25 and 75 feet deep (762 and 2286 centimeters).... > > Maybe we should send the PR crew back to Introductory Physics and teach them > > about significant digits ... > > Now for your > homework, imagine you are the boss of Public Affairs for a NASA > center. Write guidelines, in 300 words or less, which will guarantee > that your employees will always produce acceptable English-to-metric > and metric-to-English conversion figures in their press releases. May I try? "Henceforth, all press releases are to be proofread by a technical writer or writers competent in the relevant area." I doubt they'd need to put someone on it full-time. -- Mark Brader "The best you can write will be the best you are. SoftQuad Inc., Toronto Every sentence is the result of a long probation." utzoo!sq!msb, msb@sq.com -- Henry David Thoreau, 1841 This article is in the public domain. ------------------------------ Date: Tue, 30 Mar 1993 06:18:18 GMT From: Michael Moroney Subject: Acceptable metric conversions (was Re: Pioneer Venus Last Findings) Newsgroups: sci.space In article , andrew@cuenews.UUCP (Andrew Folkins) writes: > In <24MAR199319492271@kelvin.jpl.nasa.gov> baalke@kelvin.jpl.nasa.gov (Ron Baalke) writes: >> >>EVIDENCE POINTS TO OCEANS, LIGHTNING ON EARLY VENUS ... >>kilometers) was more than 10 times denser and 2120 F (1,000 degrees Celsius) >[lots of similar examples deleted] > > Maybe we should send the PR crew back to Introductory Physics and teach them > about significant digits, or at least take their calculators away... Not only that but the F to C conversion (actually it looks like a C to F conversion) is inaccurate. 1000 degrees C hotter isn't 2120 F hotter, it's 1800 F hotter. -Mike ------------------------------ Date: 30 Mar 93 01:26:57 GMT From: nsmca@acad3.alaska.edu Subject: Alaska Pipeline and space exploration/usage. Newsgroups: sci.space I ment the Alyeska and the Pipeline as an example.// Might be used for other projects.. Such as mining on the moon, mars and more.. All we need to do like someone mentioned (Henry) is find a way to dismantle the socialistic (communistic?) thinking of NASA and the US Government.. Basically let the commerical interests have a reason to explore space.. Namely take most of the stumbling blocks out of the way.. Socialism and Capitalism don't seem to work together to well.. == Michael Adams, nsmca@acad3.alaska.edu -- I'm not high, just jacked ------------------------------ Date: 29 Mar 93 18:12:33 GMT From: AJ Madison Subject: Aluminum, James Burke, and The Lost Secrets of the Ancients... Newsgroups: sci.space You folks have been talking about this for a couple of weeks now, and you've managed to mention gold occasionally, making me think that someone would eventually realize where some of these large chunks of Al could have orginated so very long ago... Yes, that's right, nuggets of almost pure metal. Collect enough nuggets, melt them down and construct the object of your choice. No massive amounts of electricity required, no bizarre loss in technology, no early leap in science which is later lost. My guess is that due to its rarity, all of the aluminum nuggets that were readily accessible in the world have been scarfed up long ago. However, there are these ore bodies lying around that can easily produce usuable metal at a reasonable profit. This is supposedly the story with gold. Currently, gold mines, really aren't, at least the ones in the continental US. The gold that is extracted is only a tiny fraction of the usuable metals in the ore, including such goodies as platinum and molybdenum. The money one gets for the gold subsidies the cost of extracting the other metals. Thats an oversimplification, since the margin on these types of mines is painfully small, and a change downward in the world market for just one metal can put a mine out of business (or idle it anyway). -- A.J. Madison PHONE: (703) 342-6700 X383 FiberCom, Inc. FAX: (703) 342-5961 P.O. Box 11966 INTERNET: ajm@fibercom.com Roanoke, VA 24022-1966 UUCP: ...!uunet!fibercom!ajm ------------------------------ Date: 29 Mar 93 23:03:32 GMT From: Jim Cook Subject: Breathing 100 atm. of anything Newsgroups: sci.space In article LLA@fs7.ece.cmu.edu, loss@fs7.ECE.CMU.EDU (Doug Loss) writes: >It seems to me that the major problem, everything else assumed to be OK, >is that at 100 atm. the viscosity of _any_ gasses is such that a human >diaphragm will fatigue and cease functioning, causing suffocation >regardless of partial pressures, etc. > >Doug Loss Where did you get that idea? --- --------------------------------------------------------------------------- C. James Cook Epoch Systems, Inc. 508-836-4711x385 8 Technology Drive JCook@Epoch.com Westboro, MA 01581 --------------------------------------------------------------------------- ------------------------------ Date: Tue, 30 Mar 1993 05:49:35 GMT From: Frank Crary Subject: Budget Astronaut (was: Idle Question) Newsgroups: sci.space In article henry@zoo.toronto.edu (Henry Spencer) writes: >>A) How big is the absolute minimum atmospheric re-entry and life >>support module for the aspiring low-cost astronaut? ... >George Herbert estimated a minimum one-man capsule as just feasible >for the new stretched Pegasus, which puts Scout out of the running unless >you can beat George's weight numbers substantially. (Probably possible, >but maybe only by fairly radical methods.) Definitely possible: George is 6'2" and insists that any project he works on be large enough to, in theory, fit himself. You could probably cut the mass of his manned Pegasus capsule by 5% to 10%, just by insisting on a 5'0" astronaut... Frank Crary CU Boulder ------------------------------ Date: Tue, 30 Mar 1993 04:23:21 GMT From: Greg Moore Subject: Commercial point of view Newsgroups: sci.space In article szabo@techbook.com (Nick Szabo) writes: >Michael Adams discusses the interesting idea of an Alyeska-type >combination of megacorps to develop the moon and Mars and distributed >profits to its members. But what profits? Moon and Mars bases are >designed for government contract pork, not to make commercial profits. >A truly commercial combine would do things quite differently. > This I can agree with. The government has no interest in profit per se. However, like Alyeska, they do have a reason to make it easier for a private corporation to do so. I believe Alyeska received some tax breaks or changes in laws in order to minimize the risk. The end benefit to the government was a larger tax base, and presumably cheaper energy for the country (which has its own advantages). >for comsat monopoly). These were long-term >investments; Comsat did not show a major return for >nearly 20 years and is only now becoming a hot stock >(paradoxically, now that its monopoly has been curtailed). > Could this though be partly due to the fact that its monopoly was broken. Competition can force a company to become leaner and meaner, and hence a better company. Is this true at all with Comsat? > >The hottest new space opportunities right now may be direct >broadcast satellites and phone cell satellites. The biggest >barriers are launch costs ($10,000/kg to polar, $50,000/kg >to Clarke orbit) and the radio frequency regulatory >environment. Launch costs only need to come down a >small amount (factor of 2) compared to the SSTO orders- >of-magnitude goal. Remote sensing also needs about a >factor of 2 to 4 launch cost reduction to be profitable >without subsidy. Contrary to the assertions of a certain >poster who should know better, commercial users >desparately want launch costs to come down, as well as for >reliability to improve. Russian launchers, if allowed to be >offered freely against unsubsidized competition, and if >marketed properly, might accomplish such reduction. >The current comsat market is >$4 billion/yr (not counting >ground stations) and growing 10-20%/yr even without >launch cost reductions. With a factor of 2-4 launch cost >reduction DBS, cellsats, and truly commercial remote >observation could expand the market to >$15 billion per >year. As a result, a fully-reusable, a good marketing of >Russian technology, or a low-refurbishing cost, >fully reusable _satellite_ launcher could find very high >demand. The latter -- an SSTO Atlas-2 >or Ariane 4 clone -- is itself a good candidate for >commercial development, if the technology >is sufficiently mature. > This sounds good, and I'd agree with it. Though, let's not get to optimistic with Russian launchers just yet. If according to a previous post Delta launches with a ground crew (year-round) of 320, there may not be a large improvement here. The Russian advantage seems to be that they mass-produce their rockets. We could do that as well. > >Here are some longer-term markets to consider: >* High-thruput microgravity/vacuum/gas-plasma >processing of native materials >* Native propellants for stationkeeping, high >maneuvarability, orbit changing, etc. for satellites, esp. >comsats and military satellites. Ah, I new it had to be sooner or later that you'd bring this up. How-ever, preceding it with longer-term does set my heart at ease. it is something to consider, but not in the near immediate future. (i.e. I'd rather see money spent on DC-X, DC-Y, AND competitors before we start making native propellants a high priority.) >* Shielding for military spacecraft. >* Direct reentry (smuggling, blockade running, etc.) Smuggling from where? earth to earth? If so, this could set a dangerous precedent. Could you imagine what would happen if a Columbian Drug Lord tried a sub-orbital shot to drop 2 tons of coke into the US. Even without any sort of SDI in place, I think that would tend to make us a hell of a lot more nervous than a few Cessna's penetrating our airspace. In actuality it seems like this would be an area that the government would have a big interest in, protecting against smuggling and blockade running. If you think differently please let me know how oyu see a commercial interest in smuggling blocking. (I can see a definite commercial interst in smuggling and blockade running, just not the opposite. "Hey, I'll pay you 200 million if you can drop 50 tons of food into Bosnia from outside the borders.") >* Large-array satellites from native materials: DBS, DSN, >ELINT, emergency SPS, etc. >* native precious metals: asteroid platinum group, high-quality >gold ores (Mars? Mercury?) Since I don't want to start a flame war, could you give an ide of what sort of time-frame you're talking here? 5 years, 10 year, 50 years, 100 years? >* Climate modification: ethane to quench chlorine radicals >(ozone problem), dust in upper atmosphere to block >sunlight (global warming), mirrors, etc. > Ack, Id want to see a HELL of a lot more research on upper atmosphere chemistry before we started doing this. I'm talking 50 years or so... >Keep in mind also current tech progress on earth that can >be spun off into space: designer catalysts and chemical >microreactors, automation, etc. A sad fact is that NASA >has spent very little of its budget exploring these possibilities. >In general, NASA and its contractors are not interested in "commerce" >except as an excuse to justify more government pork. Time for >NASA to shelve the old pork barrel fantasies of lunar & Martian glory. >If NASA wants to stay in the space business, it should devote itself >to turning space into a business. Developing a commercial mindset is >crucial, and exploring the future with business plans is a good place >to start. > Here I disagree. I don't want to defend NASA, but I don't eleive it's goal is to develop commerce, but rather to develop technology. And they've done this (not as well as thet should perhaps). DC-X is partly possible due to NASA research. Our knowledge of the other planets is due to NASA. Personally I think NASA has gotten out of the research game a little too much, but we've had enough flames on that. > >-- >Nick Szabo szabo@techboook.com ------------------------------ Date: 30 Mar 1993 02:01:41 GMT From: Shari L Brooks Subject: Coral and Dyson Sphere.. Newsgroups: sci.space In article <1993Mar27.114023.1@aurora.alaska.edu> nsmca@aurora.alaska.edu writes: >I once had an idea on how to create a dyson (sp, or dysean?) Sphere, using a >genetically engineered animal similar to a coral.. Namely using a selection of >coral and other contructs to construct the sphere (the growth of the coral >would have to be speeded up thou), one group to collect and convert the base >materials, the others group to build it.. Now to figure out how it would be >able to hanbdle space and it might work sometime in the future.. >How to get the coral to build the "reef" in the shape wanted?? A more pressing question is where would your organism get the raw materials to form such a structure in the firstplace. You need at least the mass of Jupiter for "ringworld", let alone for a dyson sphere. -- If you blow fire against the wind, take care to not get the smoke in your eyes. Big & Growly Dragon-monster | bafta@cats.ucsc.edu --------> shari brooks <-------- | brooks@anarchy.arc.nasa.gov The above opinions are solely my own. ------------------------------ Date: 30 Mar 1993 02:27:58 GMT From: "Chris W. Johnson" Subject: DC-X: Vehicle Nears Flight Test Newsgroups: sci.space No sooner do you get home than you find the latest issue of Aviation Week has just arrived with another article on DC-X... so here's another set of excerpts. Some of this, of course, has been mentioned on the net before, but there's some new info, too. From "DC-X Vehicle Nears Flight Test" by Bruce A. Smith, AW&ST, March 29, 1993, pp. 27-28: * DC-X should be rolled out on April 3rd. It's currently in the final stages of assembly and checkout. * Flight tests will begin in June at White Sands. * "Program officials said the DC-X has a .5 mass fraction--the ratio of propellant weight to gross weight of the vehicle at liftoff. A mass fraction of .9 is required to get into orbit." * "The DC-X is expected to be operated at a velocity of up to Mach 0.3, an altitude of 17,000-18,000 ft. and dynamic pressure of approximately 350 lb./sq. ft. for the White Sands tests this year." * "The initial series [of launches] will include low-altitude test- ing to evaluate the blended vehicle control provided by thrust vector control of the gimballed engines, the reaction control system and a set of flaps at the base of the aeroshell." * There will be three sets of flights. The first two will be hover tests differing in the altitudes and flight times. The first series will be conducted about 250 ft. above ground and will last 2 minutes, the second will be at 7,000-8,000 ft. and will last significantly longer (they don't say how much longer). "The second series could begin in late June or early July. The [third] series will involve the vertical landing rotation, which begins at 16,000-17,000 ft." * "[A]ll launch-related operations will be conducted by essentially a three-person crew. The flight vehicle has extensive health monitoring and built-in test systems to aid in the scaling back of support operations." "There will be five persons in the launch facility at White Sands [....]." And "[t]he crew will be rounded out by a deputy flight manager to monitor subsystems, a crewmember to load propellants and gases, the McDonnell Douglas program manager and a range safety officer." * DC-X is 40 ft. high and 13.5 ft. wide at its base. Liftoff weight will be 41,630 lb. * Propellant tanks are aluminum and hold about 3,300 lb. and 16,200 lb. of liquid hydrogen and oxygen, respectively. * Composite aeroshell by Scaled Composites. * Main propulsion by Pratt & Whitney; four RL10A-5 engines, contin- uously throttleable from 25-100% thrust. Each can be gimballed +/- 8 degrees and produces 14,000 lb. of thrust. * Reaction control system by Aerojet. It "is a gaseous oxygen- gaseous hydrogen unit with four 400-lb. thrusters." * Avionics by McDonnell Aircraft. This "includes a Honeywell computer, an F-15 inertial navigation system, a Navstar [GPS] receiver and rate sensors and accelerometers from the F/A-18 program." Chris W. Johnson Internet: chrisj@emx.cc.utexas.edu UUCP: {husc6|uunet}!cs.utexas.edu!ut-emx!chrisj CompuServe: >INTERNET:chrisj@emx.cc.utexas.edu AppleLink: chrisj@emx.cc.utexas.edu@internet# ------------------------------ Date: Tue, 30 Mar 1993 02:35:03 GMT From: Dave Michelson Subject: Gemini 8 (was Re: Artificial Gravity) Newsgroups: sci.space In article <1993Mar29.230105.24997@ll.mit.edu> nates@ll.mit.edu ( Nate Smith) writes: >> >>A thuster on a Gemini capsule came on, by error, and spun up the capsule. >>It was said at the time that if the astronauts has not shut the thuster off >>they might have blacked out. This suggest rather high values of g are >>possible with relatively small spacecraft. > >i heard a good story about this incident from a guy who was working on >some fringe aspect of the Gemini program. he related that long after >the fated mission was abnormally concluded in the Pacific, one of the >post mortem tasks given to the engineers back in the states. they >analyzed all the computer-generated instructions given to the capsule >over that crazy stretch of no control. they were told to search for >clues in the data that might help them understand what was malfunctioning >in the onboard computer. when they examined the telemetry they were >astonished. after a protracted period of futility, suddenly the thrust >corrections came pouring in right on the money and the capsule was >brought back to a nominal configuration. they were perplexed because >they could not believe the computer could make those calculations that >fast. they went back to the astronaut pilot and showed him their charts >and analysis. the astronaut smiled and said "I know. I shut it off and >switched over to manual." That's interesting. The only comment that I had ever read was that "a thruster had stuck open". No mention as to why... or how they closed it. I was under the vague impression that a short circuit was the culprit and that they had to shut down the entire OAMS system in the adapter section and fire up the re-entry thrusters in the re-entry section to stabilize the spacecraft. The mission was terminated precisely because Armstrong and Scott had used the re-entry thrusters to stabilize the spacecraft. Could they have solved the problem simply by resetting the onboard computer and then gone on with the mission? I'm simply going to have to acquire some good technical references for the Gemini spacecraft. Suggestions? --- Dave Michelson University of British Columbia davem@ee.ubc.ca Antenna Laboratory ------------------------------ Date: Mon, 29 Mar 1993 22:16:16 GMT From: "Robert J. Hall" Subject: Jules Verne Gun Newsgroups: sci.space I have a curiosity question that I am posting here because of my ignorance of Nuclear Blast physics. Suppose you have a cylindrical shaft dug to some appropriate depth. At the bottom of the shaft you have a 1 Megaton nuclear bomb. Mounted some appropriate distance above the bomb is a solid slug of metal, shaped in an aerodynamic fashion. (Presumably like a typical artillery shell.) If the weapon is detonated, what is the maximum mass of the slug that will reach escape velocity? (I'm making some big assumptions here: the slug will not deform too much and plug up the shaft; the tunnel can be sealed immediately after the slug has passed so minimal radioactive material is released; etc.) Thanks in advance for your response! -- Bob Hall | Boeing Computer Services | -- The usually disclaimers apply -- root@chicken.ca.boeing.com | ------------------------------ Date: Mon, 29 Mar 1993 21:25:00 GMT From: Dennis Newkirk Subject: KRYSTAL in separate orbit? Newsgroups: sci.space References: <1993Mar29.130451.10868@vdoe386.vak12ed.edu> Sender: Net News Nntp-Posting-Host: 145.1.146.43 Lines: 42 Source-Info: Sender is really news@CRABAPPLE.SRV.CS.CMU.EDU Source-Info: Sender is really isu@VACATION.VENARI.CS.CMU.EDU In article <1993Mar29.130451.10868@vdoe386.vak12ed.edu> ghasting@vdoe386.vak12ed.edu (George Hastings) writes: >...interesting question relayed from the CompuServe SPACEFORUM: > > 23-Mar-93 09:56:44 >Sb: KRISTAL DUMPED? >Fm: 71461.34@compuserve.com >To: ALL > >1)The russians have seperated Kristal from MIR. This could be to do >microgravity work (darn a free flying microgravity platform wish >someone would think of that here) > >2)Space Command has made a goof. > Robert G. Oler For those who are curious... While within the realm of possibility, but it's most unlikely Kristall will ever be undocked from Mir during its operational lifetime. The difficulty in redocking, and the fact that its systems are old and have little propellant left are the main reasons. Stability of Mir also is an issue in its current configuration, the "L" shape would waste more propellant... More to the point, if Kristall were to be undocked, Soyuz TM-16 would have also landed since it is docked to Kristall and can't be docked to any other Mir port (except Kristall's side port). Kristall is not designed to provide life support for a crew itself so it would have a short usefull lifetime in a crewed state. Redocking Kristall to Mir with a Soyuz docked would also be risky since there are attitude control and boost engine modules adjacent to the docking port and would impinge on the Soyuz. There are more reasons not to undock... There is also ample resources to fly microgravity experiments on unmanned spacecraft so there is no need to use something as costly and unique as Kristall for such a purpose. If use of Mir was a requirment a Progress M would do nicely. The March 15-21 Space News had a very good editorial about mistakes and omissions in US orbital element data, including some good examples. Dennis Newkirk (dennisn@ecs.comm.mot.com) Motorola, Land Mobile Products Sector Schaumburg, IL ------------------------------ Date: Tue, 30 Mar 1993 01:14:38 GMT From: nsmca@acad3.alaska.edu Subject: Metric conversion sheet request!! Newsgroups: sci.space Can someone post a short sheet on Metric to English and reverse... Yard to Meter and such.. Just for some of us who are still into feet... == Michael Adams, nsmca@acad3.alaska.edu -- I'm not high, just jacked ------------------------------ Date: Tue, 30 Mar 1993 00:52:18 GMT From: Frank Crary Subject: More water simulations Newsgroups: sci.space In article <1p7qgb$ial@usenet.INS.CWRU.Edu> as806@cleveland.Freenet.Edu (Dave McKissock) writes: >>I'm not saying that assembly of fred won't work. I am saying that our >>EVA experience isn't enough to say it can be done based only on water >>tank simulations. >I believe the work package #4 position is that we provided >sufficient evidence at the Critical Design Review that our >design meets all of the program requirements, specifically >including the requirement for on-orbit installation and >on-orbit maintenance using EVA. We verified our EVA procedures >using water tank simulations. >As I see it, the EVA community disagrees with you. They say that >based on the water simulations, they can state that EVA >procedures needed to assembly and maintain the WP-4 >hardware are do-able. The entire EVA community isn't involved at all. More precisely, those EVA people who have a major, vested interest in the Freedom program and getting WP-4 past the Critical Design Review, claim that the EVA procedures are do-able. A large number of EVA people outside the Freedom program have very serious doubts on the subject. >I wasn't aware that NASA agreed that "more EVA experiments [are >needed] so errors in the simulations can be identified and quantified". >I thought we agreed to perform more EVAs on upcoming Shuttle flights, >because someone looked at a plot of planned EVA hours versus >Shuttle missions, and noted that with SSF many hours of EVA are >needed for maintenance and assembly. So, rather than having a >step change in EVA hours, they would gradually build-up the use >of EVA. Aren't these two the same? If there were no "errors" with the simulations, then why would a gradual build-up be usefull? The whole idea of gradually working up to the Freedom-assembly EVA rate, so that any unexpected problems (errors in the simulations) can be delt with sooner, and under less urgent time constraints. Frank Crary CU Boulder ------------------------------ Date: 30 Mar 93 04:45:31 GMT From: William Reiken Subject: nuclear waste Newsgroups: sci.space In article , henry@zoo.toronto.edu (Henry Spencer) writes: > >(1) The total requirement for isotopes for those missions is measured > in kilograms. While the hazardous-waste output of nuclear power > plants *is* miniscule compared to that from fossil-fuel plants, > it's not *that* miniscule. > > (2) They need isotopes with relatively short half-lives and little or no > gamma emission, so they get a lot of power output in a form that > is easily converted to heat. > It has been proposed that by using SDI designed particle accelerators that most of the waste could be tranmutated to more useable forms. Why not build a few proccessing plants to do this? A Question: Has oil been found anywhere eles in our Solar System in the raw form that we dig it up in here on earth? If not, we may be in for some problems later. Will... ------------------------------ Date: 30 Mar 93 01:32:44 GMT From: Paul Dietz Subject: Terraforming Venus Newsgroups: sci.space I wrote: > One source of deuterium is Venus itself, where the D/H ratio is > about 100x larger than elsewhere in the solar system. But I > don't believe there's enough there, by itself. Really big bombs might be made almost entirely from materials available in Venus's atmosphere. The idea would be to exploit the reactions 1H + 15N --> 4He + 12C + 4.97 MeV and, perhaps, using the helium from that reaction, 4He + 13C --> 16O + n + 2.21 MeV (with the neutron being captured on hydrogen, yielding deuterium, which would further react, or on heavy elements, liberating about 8 MeV.) The isotopic abundance of 15N and 13C are .37% and 1.1%, respectively; the amounts in the atmosphere there can supply > 100x as much energy as is required. There is also sufficient hydrogen there, as well as enough deuterium to build boosters. Paul ------------------------------ Date: 30 Mar 93 04:36:27 GMT From: William Reiken Subject: the call to space (was Re: Clueless Szaboisms ) Newsgroups: sci.space In article , henry@zoo.toronto.edu (Henry Spencer) writes: > > Besides which, if it became a matter of national survival, Japan probably > *could* become self-sufficient in nuclear fuel quickly. Even granite > contains small amounts of uranium -- indeed, I've seen it mentioned as > a long-term uranium source in scenarios envisioning massive growth of > nuclear power -- and extraction is just a matter of economics, no big > deal if there is no other supplier. Similarly, mild isotope enrichment > is pretty easy, or you could use natural-uranium reactors like the CANDU. > Acutually Japans has an active program "started around 1987" for processing uranium out of the ocean. It is expensive, but it is also a national project. It will also prove to be a good backup just in case there are no other suppliers. Will... ------------------------------ Date: Tue, 30 Mar 1993 05:04:31 GMT From: Eric H Seale Subject: US Satellite Crashing on Brisbane?? Newsgroups: sci.space dcorbett@socs.uts.EDU.AU (Dan Corbett) writes: >The newspapers here in Australia are all abuzz with the news that >a US satellite is expected to re-enter and to fall somewhere in >Brisbane, Queensland. Anybody know anything about this? Which >satellite? Is the prediction accurate? Has it already happened? I'd doubt that it's true -- if a dying satellite is under control, it's aimed for open water; if its out of control, all bets are off (remember that Skylab was supposed to go down in the Indian Ocean). At any rate, no one in their right mind would AIM a falling bird at a city... Eric Seale ------------------------------ Date: Tue, 30 Mar 1993 01:38:50 GMT From: Anthony DeBoer Subject: Why is Venus so bad? Newsgroups: sci.space,rec.scuba In article <1993Mar29.035300.2360@cerberus.ulaval.ca> yergeau@phy.ulaval.ca (Francois Yergeau) writes: >In article mt90dac@brunel.ac.uk (Del Cotter) writes: >>arc@cco.caltech.edu (Aaron Ray Clements) writes: >>>There's also a small problem in dealing with an atmosphere that has about >>>a hundred times more pressure at the surface than at Earth. (Do you think >>>you could live in a 100atm environment? :) ) >> >>That reminds me. Don't forget that when you've got rid of all the CO2, >>there are still 2 atms of nitrogen. Can anyone confirm that this is >>dangerously close to narcosis levels? > >Nowhere near. Canadian scuba divers use Molson's law to predict >nitrogen narcosis: each 33 feet of water (1 atm) is the equivalent of >ingesting one Molson (a brand of beer). At 200 feet (7 atms total >pressure), you've had 6 beers so it's beginning to show, but at 33 feet >(2 atms total) nothing's wrong. > >And it _may_ be possible to live at 100 atms ambient, provided the >atmosphere is very, very inert and contains only very small partial >pressures of anything reactive, like O2, N2 or CO2. ... ... Otherwise, you'd have the equivalent of more than four twofours of Molson's in your system, and your bladder wouldn't fit inside your suit anymore, eh? Divers have been down to the vicinity of 2000' (approx. 60 atms, although my copy of Guiness with the exact number as of a few years ago is in a box packed away somewhere; I do remember that it was French commercial/military divers who set the record), though, which isn't quite 100 atms, but is within an order of magnitude, so eventually I'm sure we'll see it done. -- Anthony DeBoer < adb@herboid.uucp | uunet!geac!herboid!adb | adb@geac.com > NAUI # Z8800, D5482 ------------------------------ End of Space Digest Volume 16 : Issue 389 ------------------------------