Date: Sat, 12 Sep 92 05:12:04 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V15 #191 To: Space Digest Readers Precedence: bulk Space Digest Sat, 12 Sep 92 Volume 15 : Issue 191 Today's Topics: 3 Booster Questions Galileo Update - 09/11/92 Is NASA really planning to Terraform Mars? (4 msgs) Maximum Interplanetary Launch Velocity? New lunar spacecraft Pluto Direct/ options Pluto Direct Propulsion Options Pluto Fast Flyby mission goals... QUERY Re: Pluto Direct/ options (3 msgs) SSTO has been achieved Terraforming Terraforming Mars (2 msgs) Terraforming needs to begin now 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: Fri, 11 Sep 1992 22:00:41 GMT From: Josh 'K' Hopkins Subject: 3 Booster Questions Newsgroups: sci.space wingo%cspara.decnet@Fedex.Msfc.Nasa.Gov writes: >In response to Josh's statment about single engines for the booster phase of an >HLV. >Josh the NLS one booster which as an Atlas II class launcher only uses one >STME booster (600,000 lbs thrust) for 20,000 lbs to orbit. [Stuff Deleted] >Dennis, University of Alabama Huntsville I know Dennis. However, I don't consider this a Heavy Lift Vehicle. I can't calulate how much a single F-1 can put into orbit without knowing what else you have in mind, but I don't think the extra thrust is enough to put it in the HLV class either. -- Josh Hopkins "If you are sitting in an exit row and you cannot read this card or cannot see well enough to follow these instructions, please tell a crew member." j-hopkins@uiuc.edu -United Airlines safety instructions ------------------------------ Date: Sat, 12 Sep 1992 05:09:54 GMT From: Ron Baalke Subject: Galileo Update - 09/11/92 Newsgroups: sci.space,sci.astro,alt.sci.planetary Lines: 98 Source-Info: Sender is really news@CRABAPPLE.SRV.CS.CMU.EDU Source-Info: Sender is really isu@VACATION.VENARI.CS.CMU.EDU Forwarded from Neal Ausman, Galileo Mission Director GALILEO MISSION DIRECTOR STATUS REPORT POST-LAUNCH September 4 - 10, 1992 SPACECRAFT 1. On September 8, realtime commands were sent to change the System Fault Protection (SFP) AACS-INIT (Attitude and Articulation Control Subsystem) pointing slot from the Earth to the Sun prior to the Dual Drive Actuator (DDA) No. 3 pulse activities. This change will allow the spacecraft to return to a sun-pointed attitude if an AACS Power on Reset (POR) occurs during the DDA No. 3 pulse activities (see Special Topic No. 2). 2. On September 8, the DDA pulse mini-sequence memory load went active. The warming turn to a 45-degree off-sun attitude commenced at approximately 1536 UTC and completed at 1608 UTC. The first of two motor turn on pulses occurred at 1826 UTC for approximately two seconds, as planned. The DDA motor temperature was approximately minus 12 degrees C at turn on. The DDA motor current data analysis is in progress. 3. On September 9, after approximately 28 hours at the warming attitude, the second motor turn on pulse occurred at 1916 UTC for approximately two seconds, as planned. The DDA motor temperature was approximately plus 9 degrees C at turn on. DDA motor current data playback completed at approximately 1921 UTC on September 10 and data analysis is in progress. Additionally, the spacecraft, under stored sequence control, was commanded back to a six degree off-sun attitude at approximately 1923 UTC. After the sun acquisition, sun gate data was collected to determine if an antenna rib is still obscuring the sun gate signal. Preliminary data analysis indicates that the sun gate is still obscured, indicating no ribs released; analysis is continuing. 4. The AC/DC bus imbalance measurements exhibited some change. The AC measurement remained unchanged and reads 3.3 volts. The DC measurement has ranged from 120 DN (14.0 volts) to 140 DN (16.4 volts) and now reads 129 DN (15.1 volts). These measurement variations are consistent with the model developed by the AC/DC special anomaly team. 5. The Spacecraft status as of September 10, 1992, is as follows: a) System Power Margin - 68 watts b) Spin Configuration - Dual-Spin c) Spin Rate/Sensor - 3.14rpm/Acquisition Sensor d) Spacecraft Attitude is approximately 5 degrees off-sun (leading) e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1 f) General Thermal Control - all temperatures within acceptable range g) RPM Tank Pressures - all within acceptable range h) Orbiter Science- UVS, EUV, DDS, MAG, EPD, and HIC are powered on i) Probe/RRH - powered off, temperatures within acceptable range j) CMD Loss Timer Setting - 264 hours Time To Initiation - 206 hours TRAJECTORY As of noon Thursday, September 10, 1992, the Galileo Spacecraft trajectory status was as follows: Distance from Earth 64,280,500 miles (.69 AU) Distance from Sun 141,694,300 miles (1.53 AU) Heliocentric Speed 55,100 miles per hour Distance from Jupiter 642,944,800 miles Round Trip Light Time 11 minutes, 38 seconds SPECIAL TOPIC 1. As of September 10, 1992, a total of 8114 real-time commands have been transmitted to Galileo since Launch. Of these, 3236 were pre-planned in the sequence design and 4878 were not. In the past week, 1 real time command was transmitted and pre-planned in the sequence design. In addition, 5677 mini-sequence commands have been transmitted since March 1991; 3519 were pre-planned and 2158 were not. In the past week, no mini-sequence commands were transmitted. Major command activities this week included commands to change a System Fault Protection parameter. 2. The Dual Drive Actuator (DDA) pulse mini-sequence No. 3 covers spacecraft activities from September 8 to 11, 1992. The warming turn to a 45-degree off-sun attitude along with the first DDA two second motor turn on pulse occurred on September 8. The spacecraft remained at the warming attitude for approximately 28 hours. The second DDA two second motor turn on pulse occurred just prior to turning back to approximately a 6 degree off-sun attitude. Sun gate data was collected on September 10. The star scanner checkout along with the collection of wobble data is scheduled for September 11. ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Anything is impossible if /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you don't attempt it. |_____|/ |_|/ |_____|/ | ------------------------------ Date: Fri, 11 Sep 1992 21:00:14 GMT From: Henry Spencer Subject: Is NASA really planning to Terraform Mars? Newsgroups: sci.space In article <1992Sep10.151758.5676@neptune.inf.ethz.ch> aweder@iiic.ethz.ch (Andreas Michael Weder) writes: >>>*at least* 500 billion dollars (according to a NASA researcher). >>According to a NASA politician, you mean. >>There is no technical reason why it has to cost that much... > >I do believe that the figure would probably around 500 billion dollars. >Remember: the whole mission would take more than 2 years to accomplish... As best I can tell, Zubrin has done his homework. Cost estimates are necessarily somewhat speculative, but he's not off by an order of magnitude... if you do things *his* way. >You'd have to build a fairly big space ship to provide all the stuff needed >to do such a flight (life support, food, recycling of water and waste,...). His ship size appears to be adequate to the job. This guy is not stupid; he's not going to overlook something gross like that. Problems with his scheme would be found in the details. >BTW, the figure's from a researcher at JPL. What are the *assumptions* behind that figure? Assembling a zillion-ton ship in Earth orbit using only the shuttle as a launcher and taking all the fuel for the return trip from Earth, I bet. >Nevertheless, I would appreciate a short summary of Bob Zubrin's idea. I'll see if I can produce one in the next few days. The central idea I can quote you right now: using local resources -- making your return-trip fuel using the CO2 in the Martian atmosphere -- to scale down transport requirements to something comparable to a lunar mission. -- There is nothing wrong with making | Henry Spencer @ U of Toronto Zoology mistakes, but... make *new* ones. -D.Sim| henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 11 Sep 92 21:45:32 GMT From: Josh 'K' Hopkins Subject: Is NASA really planning to Terraform Mars? Newsgroups: sci.space sysmgr@king.eng.umd.edu (Doug Mohney) writes: >In article <1992Sep11.042246.22983@ucsu.Colorado.EDU>, knapp@spot.Colorado.EDU (David Knapp) writes: [Lots of wrods from both sides deleted. I'm not sure I cut out much substance] >>>Besides, population growth is self-correcting. >>Ultimately, yes, but you won't like the way it corrects itself. >Let me key you in: Starvation in Ethopia and Somalia is due to political >warfare and strife, not because there's a lack of food production. We're not >going to starve ourselves off the planet. I've always wondered about logic like this. I suppose the increasing population in sub-saharan Africa to going to stabilize politics thus making food available? Sure. Makes sense to me. If there's food in the grain elevator they have no excuse for going around and starving themselves to they? >>>We've been running out of fossil fuels for 100 years. Before that, there was a >>>fear of a great shortage of whale oil, due to overhunting. >> >>No, we will *run out* of fossil fuels in less than fifty years. >Allegedly. Before we run out, the price on a barrel of oil will go up. >What happens when the price of oil goes up? People start to conserve, >industries develop new technologies to extract oil more efficiently, and >alternatives are developed which are price competitive to substitute for oil. I see, so In ten years, all those green technologies the crazy tree huggers have been working on are going to be suitably conservative for you to use? (Okay, it's a little bit of a stretch to call a poor engineer forced to wear a tie a "tree hugger"). >>When we do run out of fossil fuels, I'm sure I won't see you shoving to get >>an electric car because you were so convinced it wouldn't be an issue. I hope >>you like the bus. >Naw, I'll be drivin' my Saturn III (GM, not NASA product:) past your raggy >eco-bike with my "John DeArmond for President" bumpersticker in your face. >:-> And I'll be driving a GM Impact which I saved up for by turing off the lights when I wasn't using them and riding my bike when I didn't need a car. If you think electric cars or even bikes have to be "raggy" you obviously aren't very familiar with either. >>No, really, I see what you're saying, until we see that it is a problem, >>we should not worry about it. Good strategy. >Sounds good. Prove to me there is a problem. I seriously doubt that my computer will get stolen, but it's insured. Similarly, I don't mind suggesting someone with her hair piled a foot high should make the ultimate acrifice and skip her aerosol can tomorrow. I don't mind doing my errands all at once to save gas. >Will you be the first to >hang yourself in order to save the ecosystem? I assume this was meant sarcastically, but there are people out there so rabidly against the concept of evironmental concern that they have these reactions seriously. -- Josh Hopkins "If you are sitting in an exit row and you cannot read this card or cannot see well enough to follow these instructions, please tell a crew member." j-hopkins@uiuc.edu -United Airlines safety instructions ------------------------------ Date: 11 Sep 92 21:19:44 GMT From: Josh 'K' Hopkins Subject: Is NASA really planning to Terraform Mars? Newsgroups: sci.space amon@elegabalus.cs.qub.ac.uk writes: >> Even if you ignore all the globe-threatening issues, *population* growth, >> which you can *count on*, will still be one of our greatest challenges. >Read some demographics books. Population has been shifting from high birth >rate/high mortality to low birth rate/low mortality for over a century. >Population growth follows and S curve because there is a social lag between >the mortality decline and the change in desired family size. > Much of the "Third World" >got modern medicine almost as a step function and also started from higher >population bases and lower education/technology bases. >Nonetheless, country by country they are going through the transition to >stability. The exception so far has been africa, which seems to have very >stable social structures making large families desirable. Not to fear. It >will change. Whether by conscious decision or by the four horsemen is their >own decision to make. Now wait a minute. I'm glad to see that you can discuss this issue without laughing it off or predicting armageddon. However, I missed whatever facts you're using to suggest that Africans prefer having 7 children a piece. (That is in fact the average or below average in several countries). The major reasons for high birth rates, as I understand it, are that birth control simply is not available and that women don't get a say in how many children the family has. I don't think we can just sit back and ignore this and wait for Africa to pull itself into the first world. -- Josh Hopkins "If you are sitting in an exit row and you cannot read this card or cannot see well enough to follow these instructions, please tell a crew member." j-hopkins@uiuc.edu -United Airlines safety instructions ------------------------------ Date: 12 Sep 92 00:22:07 GMT From: "Thomas H. Kunich" Subject: Is NASA really planning to Terraform Mars? Newsgroups: sci.space In article jbh55289@uxa.cso.uiuc.edu (Josh 'K' Hopkins) writes: > >I've always wondered about logic like this. I suppose the increasing >population in sub-saharan Africa to going to stabilize politics thus >making food available? Sure. Makes sense to me. This is the point I've been listening for. It really doesn't matter what the reasons for starvation are. It is happening. >I see, so In ten years, all those green technologies the crazy tree huggers >have been working on are going to be suitably conservative for you to use? Ten years won't be enough time for the political force to be generated to spend the money to build these energy resources on a large wnough scale. I am afraid that by the time it it plain enough to the man on the street it will already be too late to start. With the national debt at it's present point we simply cannot afford to do this now. If the politicians cannot even settle an issue as important as the economic well being of the country, how do you suppose they will face something like changing power sources?> >If you think electric cars or even bikes have to be "raggy" you obviously >aren't very familiar with either. You are not going to feed a world on the (non-existant oil) driven green revolution by riding bicycles after the oil is gone, or by burning coal to generate electricity to supply energy to electric vehicles. This whole string relates to space. (Believe it or not) This is because a space faring species is one with energy independance of a large order. We are who we are mostly because of the cheap and plentiful energy storage that mother nature was so kind to leave laying about. This has turned out to be even more plentiful then believed in the 50's but is, nevertheless, of a finite nature. There _are_ means and methods that could greatly reduce the impact of a petroleum-less society, but most of these need to be financed heavily and soon. The political enertia of the world's governments and the staggering global debts may simply make it impossible for the required steps to be taken in time for any meaningful corrections to be made. I can tell you that if you think that China and India are in any position to survive a large scale environmental problem like the failing of a single year's monsoon then there is more trouble in the world than even I imagine. > ------------------------------ Date: 12 Sep 92 00:21:45 GMT From: Andrew - Palfreyman Subject: Maximum Interplanetary Launch Velocity? Newsgroups: sci.space Relative to the Earth, what is the highest velocity we can currently boost to for interplanetary missions? - is this significantly higher than typical orbit speeds? Would a gravity assist from the Moon make much difference, even if repeated? Is the maximum speed likely to change drastically due to improved technologies in the near future? ObNote: Yes, I did check the FAQ and yes, I did interchange "velocity" and "speed". -------------------------------------------------------------------------- | lord snooty @the giant | Would You Like Fries With That? | | poisoned electric head | andrew_-_palfreyman@cup.portal.com | -------------------------------------------------------------------------- ------------------------------ Date: 11 Sep 92 22:20:23 GMT From: John Stevenson Subject: New lunar spacecraft Newsgroups: sci.space In article <1992Sep6.013607.8183@dartvax.dartmouth.edu> Frederick.A.Ringwald@dartmouth.edu (Frederick A. Ringwald) writes: [stuff deleted] > While old data sets often contain overlooked gems, for some questions, > they will not help at all. The Lunar Orbiters did optical imaging from > roughly equatorial orbits about the Moon; if you wanted to look for > lunar water, you'd need a polar-orbiting spacecraft with infrared > imaging and better, also spectroscopic instrumentation - not unlike > what's going on the Mars Observer. > Lunar Orbiters 5 and 6 were in polar orbits. The radio navigation data collected (which would be used to develop models of the lunar gravitational field) are either lost or stored on punch cards and so far unretrievable. JPL was attempting to recover this data in support of the Lunar Observer mission, which has since been cancelled. The loss of such pricey and important data is representative of the post Apollo era. :-( The lunar resource mapping mission by SEI out of JSC selected two contractors for the next phase (not TRW :-( ) but, of course,the congresscritters have decimated the SEI budget. Don't hold your breath. John Stevenson hangfore@spf.trw.com ------------------------------ Date: 11 Sep 92 20:51:54 GMT From: Henry Spencer Subject: Pluto Direct/ options Newsgroups: sci.space,alt.sci.planetary In article <1992Sep11.172931.1004@cco.caltech.edu> kwp@wag.caltech.edu (Kevin W. Plaxco) writes: >Voyager 1 flew most of the Jupiter-Saturn-Pluto trajectory, but was >diverted get a closer look at Titan. I have often wondered, >considering the somewhat unexpected longevity of the Voyagers, how >many times the folks at JPL kicked themselves for not trying >harder to lobby for the J-S-P trajectory for Voyager 1. The longevity wasn't really the issue; a close look at Titan was Science Priority Number One at Saturn. Voyager 2 wasn't okayed for the on-to- Uranus trajectory until Voyager 1 completed Titan encounter successfully, as I understand it. Given the timing and orbits, the decision that a close look at Titan was imperative meant that one of the Voyagers was not going on to another planet after Saturn. Simple as that. Of course, as it turned out, Titan was a disappointment... but there was no way to be sure of that in advance. -- There is nothing wrong with making | Henry Spencer @ U of Toronto Zoology mistakes, but... make *new* ones. -D.Sim| henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Fri, 11 Sep 1992 21:11:11 GMT From: Henry Spencer Subject: Pluto Direct Propulsion Options Newsgroups: sci.space In article pgf@srl03.cacs.usl.edu ("Phil G. Fraering") writes: >/... You really cannot do a Pluto >\orbiter in a reasonable amount of time with 1960s propulsion technology, >/which is what all currently-planned missions use. > >Just out of curiosity, is there a way to convince them to use post-early- >1960's technology, like an ion drive of some sort? Not until somebody space-qualifies modern hardware of that sort, so it can be done without major risk of cost or schedule overrun. This particular mission is time-critical because of the impending freezeout of Pluto's atmosphere, so the fewer unknowns the better. There is also a serious technical problem with using electrical propulsion for this particular mission: what's your power supply? RTGs are too heavy for major power outputs, and solar doesn't work so well in that neighborhood. It would have to be a nuclear reactor. A sound idea, but not something that can be done in a hurry. -- There is nothing wrong with making | Henry Spencer @ U of Toronto Zoology mistakes, but... make *new* ones. -D.Sim| henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 11 Sep 92 22:10:34 GMT From: Steinn Sigurdsson Subject: Pluto Fast Flyby mission goals... Newsgroups: sci.space In article pgf@srl07.cacs.usl.edu (Phil G. Fraering) writes: irwin@iago.caltech.edu (Horowitz, Irwin Kenneth) writes: >Folks, > Hearing all these wild ideas passed around on this Pluto flyby has >led me to try to remind everyone of a few things concerning this mission. >First, Staehle is trying to bring back the concept of "faster, better, >cheaper" that Goldin is pushing, which was so successful in the '60s. But ion drives are tested. JPL tested much worse ones than we have now back in the '70's, as part of project SERT. (or did someone else run the program? I thought it was JPL...) So it's tested. Also, I'll bet SERT was pretty cheap. We know the exhaust is faster. How long did they fire the test engines for? There's a big difference between concept testing and operation, for a pluto flyby you need high delta v, if you use a cheap booster to get it off Earth and use an ion engine to get the delta v to get it to Pluto you have to have confidence the things will work for the (months long?) boost phase. My understanding is that electrode erosion and other finicky details are not well enough understood, at least as of 4 years ago, and I don't believe any have been flown in the interim. So, ion drives are cheaper and faster than ordinary propulsion. I don't know of a "better" criteria you can apply... That you can be reasonably sure the mission will succeed? | 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: Fri, 11 Sep 1992 21:04:15 GMT From: Henry Spencer Subject: QUERY Re: Pluto Direct/ options Newsgroups: sci.space In article <716176102.F00002@blkcat.UUCP> Shawn.McCarthy@p902.f349.n109.z1.fidonet.org (Shawn McCarthy) writes: >Has the possibility of a light-sail been looked into? use it for accelleration >from the 'bright' area near the earth, then brake off Jupiter's light... Nothing in the solar system except the Sun emits/reflects enough light to be useful for a lightsail. Besides, braking at Jupiter doesn't do you any *good*. The outer solar system is *enormous*, far larger than the inner solar system. Jupiter's distance is only a small fraction of the distance to Pluto. -- There is nothing wrong with making | Henry Spencer @ U of Toronto Zoology mistakes, but... make *new* ones. -D.Sim| henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Fri, 11 Sep 1992 21:07:05 GMT From: Henry Spencer Subject: QUERY Re: Pluto Direct/ options Newsgroups: sci.space In article <15008@mindlink.bc.ca> Nick_Janow@mindlink.bc.ca (Nick Janow) writes: >Would it be possible to aerobrake at Uranus or Neptune... It's a long way from Uranus or Neptune to Pluto, even when the planets are lined up nicely... which they aren't now. Any braking you do really has to be done very close to Pluto. It is too far away from everything else. -- There is nothing wrong with making | Henry Spencer @ U of Toronto Zoology mistakes, but... make *new* ones. -D.Sim| henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 11 Sep 92 14:43:01 GMT From: Mario Wolczko Subject: QUERY Re: Pluto Direct/ options Newsgroups: sci.space In article , henry@zoo.toronto.edu (Henry Spencer) writes: > It is extremely difficult to combine a reasonable payload and a manageably > short trip time with an orbiter mission. Pluto is *a long way away*; to > get there in under a decade, the probe has to be fast. Killing all that > velocity is inordinately expensive in mass. Given that there are two bodies (Pluto and Charon), would it be possible to lose enough energy by sling-shotting around them repeatedly (the opposite to what's been done by the Voyagers, Ulysses, etc., at Jupiter)? Or are they too small to have enough of a gravitational effect? ______ Dept. of Computer Science Internet: mario@cs.man.ac.uk /~ ~\ The University uucp: mcsun!uknet!man.cs!mario ( __ ) Manchester M13 9PL JANET: mario@uk.ac.man.cs `-': :`-' U.K. Tel: +44-61-275 6146 (FAX: 6236) ____; ;_____________the mushroom project___________________________________ ------------------------------ Date: Fri, 11 Sep 1992 23:03:39 GMT From: Frank Crary Subject: SSTO has been achieved Newsgroups: sci.space In article <1992Sep10.211155.23609@cco.caltech.edu> kwp@wag.caltech.edu (Kevin W. Plaxco) writes: >But what about a martian SSTO? I have seen several discussions >about the logistics of a manned (or even unmanned return) mars >mission, but I have never seen a proposal for how to achieve >mars orbit after the mission has ended. How difficult will this be? Not very difficult at all. In fact, I can't recall any manned architectures that use multi-stage rockets for this. (Mars Direct uses a two-stage rocket but to enter a Earth-return trajectory, not just to enter Martian orbit.) Frank Crary CU Boulder ------------------------------ Date: 11 Sep 92 21:15:14 GMT From: "Thomas H. Kunich" Subject: Terraforming Newsgroups: sci.space In article <15054@mindlink.bc.ca> Nick_Janow@mindlink.bc.ca (Nick Janow) writes: >roberts@CMR.NCSL.NIST.GOV (John Roberts) writes: > >> I believe that portion of the discussion involved a search for terrestrial >> organisms that could live on Mars unmodified. I believe the Viking tests >> found *no* organic material, and they should have found some from meteorite >> impacts. > >The discussion wandered a bit, and I got the impression that the "Mars' surface >conditions would kill any Terran life" argument was being used to argue against >_any_ life able to exist there. Viking scratched only the superoxidized >surface; would it have noticed silica fibres? That is slightly incorrect. I suggested that it woul be possible to find either naturally occuring organsms or bioengineered organism to colonize Mars. ------------------------------ Date: 11 Sep 92 21:18:19 GMT From: "Thomas H. Kunich" Subject: Terraforming Mars Newsgroups: sci.space In article <1992Sep11.074027.14938@rose.com> brad.thornborrow@rose.com (brad thornborrow) writes: >Am I missing something, > > I havn't been following the entire conversation here, but it seems >to me everybody is missing the gravity problem. Last time I checked, >Mars' gravity was not strong enough to keep oxygen molecules from escaping >into space over time. So, even if one could start plant-life on Mars, >you'd have to have a heck of a lot of it to keep the oxygen from just >"floating away"!!! The atmospheric pressure of Venus would seem to prove pretty conclusively that it should be possible to maintain an atmosphere on Mars. > ------------------------------ Date: Fri, 11 Sep 1992 23:15:15 GMT From: Paul Dietz Subject: Terraforming Mars Newsgroups: sci.space In article tomk@netcom.com (Thomas H. Kunich) writes: > The atmospheric pressure of Venus would seem to prove pretty conclusively > that it should be possible to maintain an atmosphere on Mars. Why? Venus is nearly as big as Earth. Paul F. Dietz dietz@cs.rochester.edu ------------------------------ Date: 11 Sep 92 18:48:47 GMT From: Jeff Jackson Subject: Terraforming needs to begin now Newsgroups: sci.space > use the glass to form solar mirrors > to fire the glass factories Yes, I had thought of that as well. > The vapour is condensed by cool sea water flowing into the > system along the tops of the evaporators. That's an item I hadn't figured out, though one idea I had would be to pump it to deeper cooler currents (if they exist in the nearby ocean/sea -- such as the currents that run along the US's west coast) or pump the vapour into storage facilities to condense in the cool night air (I made that one up just now). Or, how about irrigating directly with vapour. Pump the vapour in pipes a few feet underground with holes periodically where the vapour can espace and pass through the soil, which could cool and absorb the water. Plant plants with deep roots to get to the water. > labour With all the unemployment in the world? Seems like a great project for workfare (I don't believe in welfare). You have a huge labour fource sitting there starving, unable to grow crops or doing anything else to enrich & feed themselves. You give them food and shelter in exchange for them working on the project & once its built, they can start growing their own food and become self sufficient. > glass requires lime Don't know much about this. Any limestone in Africa, Outback, etc? > how do you pump the seawater cheaply? This ones' easy. Tides & waves & gravity & sun. Water will just flow into the canals if they can be kept at sea level or lower -- I know nothing of the topography of the world's deserts, so this might not be doable. Design a pump that will pump sea water using the power from rising and lowering tides and waves and line the cost solid with them (Maybe puting them a few miles out, so they can't be seen by the tourists on the beaches). Steam power comes to mind too. Put some of the solar furnaces along the beach and canal to create steam power. -- ============================================================================ Jeffrey Glen Jackson _|_Satan jeered, "You're dead meat Jesus, I'm gonna jgj@ssd.csd.harris.com | bust you up tonight." x5120 | Jesus said, "Go ahead, make my day." ~~~~~~~~~ -- Carman, "The Champion" -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Politically, I am neither conservative nor liberal -- I think for myself instead. ------------------------------ End of Space Digest Volume 15 : Issue 191 ------------------------------