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#22
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Moon Base baby steps
Joe Strout wrote in message ...
In article , (Ross A. Finlayson) wrote: I guess my idea of a moonbase is a bunch of domes, using the "regolith" as structural material. Cylinders are more likely than domes, at least as a first step. And the regolith is shielding material, not structural material. ... That makes sense. I'm wondering about "lava tubes on the moon". I guess I was under the impression that besides Earth only Jupiter's moon Io had active volcanic activity, and I was thinking Luna was a cold chunk of rock. Yet, I read here that Luna has a molten, presumably iron, core, thus that it would have similar magnetic fields to Earth. Lava tubes, miles long underground caverns similar to lava tubes on Earth, where higher temperature magma flowed out and left behind open space, would probably be among the major geologic reasons for their to be caverns on the moon with the lack of running water. I just had never heard of their existence before yesterday, and don't know of any on the moon itself. I think there should be shortly ten or fifteen satellites about the moon, these would be necessary for a variety of surface operations. I may be wrong, the moon has no appreciable atmosphere, thus no ionosphere and only line-of-sight radio communications. A satellite array would be critical in providing global (?) coverage of communications availability to surface operations. About heavy lift, I agree with you in that smaller launches may be more efficient. I guess I was thinking of heavy lift as total lift capacity, but certainly the launch of very large items to not require their assembly in space is also a consideration. I always why there weren't more air-boosted launches, an aerodynamic launch plane flies a hundred thousand feet high and the launch vehicle separates and boosts to orbit from high in the sky. Maybe that's a misconception from seeing the space shuttle flown around piggyback, and about how high is low Earth orbit. Geosynchronous orbit is much farther away than low Earth orbit, some 22,000 miles or something. Then, let's see, I think the moon is 600,000 (500-700) kilometers away, and Mars variously 20 million to 200 million. I was reading about the Shuttle-C for cargo and saving the liquid fuel tanks in holding orbits, I think that's a good idea. What prevents the addition of new modules to the ISS, Freedom, the International Space Station, every year? What's so great about the ISS's orbit that it is there? I got to browsing the "Lunar Prospector" web page, the probe that was landed into the polar crater, almost. http://lunar.arc.nasa.gov/resources/news.htm Lunar Prospector was about first US moon mission since Apollo 17, then there's Clementine. About mapping the lunar surface and within it, I wonder if ground penetrating radar instruments would be any good, for example for discovering lava tubes. They might only work from the ground. We can see the moon's surface pretty well from here and space telescopes. I read that Mars Express is using some form of deep radar. One of these documents from the website there have a low lunar orbit being around 100 kilometers. Assuming that Lunar Prospector was pretty conservative, it says the flight time to the moon, lunar orbit, is around 100 hours, from LEO, low Earth orbit. "From a given launch site, a launch to the moon is possible on each day of the month, with two launch times (roughly 12 hours apart) available on each launch data. ^3", from "Lunar Prospector Mission Design and Planning Support" , referring to "A 70th Degree Lunar Gravity Model (GLGM-2) from Clementine and Other Tracking Data." The website has Lunar Prospector at around 63 million dollars (yeech) in 1998. Mars Pathfinder, from the previous year, was much more complicated as it had a lander in addition to the orbital component and went to Mars, and research says it cost about 265 million. This is where the Viking Mars probes from the 70s cost around 3 billion in adjusted dollars. I guess what I'm trying to figure out is if a mailbox full of cement was to be launched into lunar orbit, what would be its costs? Further research, I am not a regular follower of space industry news, further research leads to information about the ESA's, European Space Agency's, SMART-1 lunar probe that is using ion engines to waft it gently from Earth orbit that was reached atop an Ariane 5 into lunar oribt sometime in 2005, with a travel time to the moon of 18-20 months. A comment notes SMART-1 cost around 110 million euros and was launched with two other satellites aboard the Ariane 5. I have heard varying claims about the functionality of solar sails, if they work they're definitely a consideration for long duration orbiters as they wouldn't have to carry reaction mass for that system. An orbiter could have both solar sails and ion/rocket drives, redundant systems that if correct would allow an orbiter many years of maintenance free operation, rockets for insertion and sails for correction. The newspaper says the current U.S. Mars missions tally to about 820 million, with Mars Express around 300 million euros. http://www.esa.int/science/marsexpress/ International Launch Services here has some documents about the capabilities of the Saturn and Proton families of booster rockets. http://www.ilslaunch.com/missionplanner/ It seems pretty expensive to launch a payload into orbit. That's a problem with monopolies, although I guess it's a market economy, there are presumably some crazy regulatory controls on ballistic rocketry. It's a lot easier to fantasize about thousands of launches per year than to design/build launching something to the moon. So let's see: twenty space telescopes space planes twenty semi-permanent lunar orbiters increased space station twenty-two hundred moon rovots (roving robots) ten semi-permanent Mars orbiters ten Mars rovots How about 1.5 billion dollars. Hey right on, man. Ross |
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Moon Base baby steps
Joe Strout wrote in message ...
In article , (Ross A. Finlayson) wrote: I guess my idea of a moonbase is a bunch of domes, using the "regolith" as structural material. Cylinders are more likely than domes, at least as a first step. And the regolith is shielding material, not structural material. Agree cylinders will be first, covered in regolith. But domes could easily follow. The "structural material" will be a high strength fabric. Regolith is not suited to tension structures. Assuming you can get some silicates out of the dirt and rocks there, then a primary step for long term habitibility is food production, using the materials to build largescale greenhouses to grow earthly plantlife. That's certainly one step I'd like to see, though I doubt it's a primary one -- you could live on imported food for a while. 1. Extraction of oxygen 2. Production of glass metals such as aluminium 3. Production of solar cells 4. Production of food 5. Creation of a mass driver snip I agree we should be separating cargo and people. Esprecially if we can get cargo from LEO to Lunar orbit by electric propulsion. Landing stuff on Earth is kind of easier than landing on the moon, it has an atmosphere, so giant supertankers could be aeroformed in space and floated gently to land in the ocean with maybe only a few kilotons. Landing on Luna requires retrorockets. Well, yes, but the delta-V to the Moon's surface is substantially less too. As is the gravity for that matter. Of the two, I'd much rather land on the Moon than on the Earth. Hopefully, the aim will be to get lots of mass off the moon for which a mass driver is probably the easiest way. (Though NASA should look at aluminium / oxygen rockets). snip On the surface what you want are solar cells, tons of 'em. Perhaps. A small fission plant would be a heckuva lot easier, though. 1. Put down a 1 MW fission plant (weighs about 30 tons) to provide constant electricity. 2. Add solar panels made on the moon to provide day time electricity. Certain high energy processes (for example, electrolysing potassium and fluoride) would take place only during the day. 3. Eventually, a solar power station at L1 would beam down energy as microwaves to the base, and perhaps even as laser to individual vehicles. About getting to the moon, what I think should be done straightaway are dozens of unmanned micromissions. We need about eighty or ninety remote control ATVs zooming around up there, in, say, fifteen months. More fumes. However, if you said "five years" I would tend to agree. Several things they should do immediately. One of these is to give a few million $ in research grants to some University Chemistry department to test methods for processing lunar regolith. They should aim to build and test a prototype chemistry unit, perhaps along the lines described he http://www.asi.org/adb/02/13/02/silicon-production.html If that can be made to work, give a few million $ in research grants to some University Engineering department to build a machine that could produce useful aluminium and glass shapes. Something like an aluminium frame, glass walled 4m diameter tunnel. |
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Moon Base baby steps
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Moon Base baby steps
(Ross A. Finlayson) writes:
Joe Strout wrote in message ... In article , (Ross A. Finlayson) wrote: I guess my idea of a moonbase is a bunch of domes, using the "regolith" as structural material. Cylinders are more likely than domes, at least as a first step. And the regolith is shielding material, not structural material. ... That makes sense. I'm wondering about "lava tubes on the moon". I guess I was under the impression that besides Earth only Jupiter's moon Io had active volcanic activity, and I was thinking Luna was a cold chunk of rock. Non sequitur. There is no need for a body to have _current_ volcanic activity for it to currently still have lava tubes. _Ancient_ volcanic activity would have been quite sufficient to create them; on a geologically "quiet" body with few quakes, some of them might not yet have collapsed. Yet, I read here that Luna has a molten, presumably iron, core, thus that it would have similar magnetic fields to Earth. First of all, the still-hypothetical lunar iron core, =IF= it exists at all, is proportionally many times smaller than Earth's extra-large iron core. Second, it is not sufficient to merely have an iron core; the core must still be undergoing active convection due to a sufficient source of internal heat generation, rather than being stably statified. Third, the Moon rotates so slowly that the strong coriolis forces essential to magnetic dynamo action are negligible. Hence, your belief is falsified not once, but threefold. -- Gordon D. Pusch perl -e '$_ = \n"; s/NO\.//; s/SPAM\.//; print;' |
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Moon Base baby steps
In article ,
(Ross A. Finlayson) wrote: I'm wondering about "lava tubes on the moon". I guess I was under the impression that besides Earth only Jupiter's moon Io had active volcanic activity, and I was thinking Luna was a cold chunk of rock. Heck no! The Moon is littered with lava tubes, and big ones too (up to about a kilometer in diameter). Not that we've actually observed an intact tube yet -- but we observe many rilles, which are most likely collapsed tubes, and gaps in the rilles are most likely intact tubes. Yet, I read here that Luna has a molten, presumably iron, core, thus that it would have similar magnetic fields to Earth. Er, no, the Moon is cold and dead now, with no appreciable magnetic field. And I don't think it has much iron, either. The Moon is formed from the Earth's crust; most of the iron in the Earth was already at the core by that time, and didn't go into the Moon. (Earth is an unusual planet in that most of the planet's crust is hanging way up over our heads. This may be why we have dry land, some theorists say, and may be relevant to the development of civilization... but I digress.) Lava tubes, miles long underground caverns similar to lava tubes on Earth, where higher temperature magma flowed out and left behind open space, would probably be among the major geologic reasons for their to be caverns on the moon with the lack of running water. Yes, exactly. Only they're much bigger on the Moon than they are here. I just had never heard of their existence before yesterday, and don't know of any on the moon itself. Dude, you're missing out. Everybody should know about these. Do a Google search for "lunar lava tubes" and read a while. Or even go to the library or Amazon -- there have been a couple of good books about them. I think there should be shortly ten or fifteen satellites about the moon, these would be necessary for a variety of surface operations. I may be wrong, the moon has no appreciable atmosphere, thus no ionosphere and only line-of-sight radio communications. A satellite array would be critical in providing global (?) coverage of communications availability to surface operations. Right. A communications array is exactly the sort of infrastructure Uncle Sam should be building. I always why there weren't more air-boosted launches, an aerodynamic launch plane flies a hundred thousand feet high and the launch vehicle separates and boosts to orbit from high in the sky. Maybe that's a misconception from seeing the space shuttle flown around piggyback, and about how high is low Earth orbit. It's not the height that matters; to get to orbit, you need speed. It's about Mach 27, IIRC. That's really amazingly fast. The extra Mach 0.5 you might get from the carrier plane is insignificant. The only real savings of launch from altitude is that you can tune your rocket engines for vacuum or near-vacuum, instead of having to have some compromise between efficiency at sea level and efficiency at altitude. I was reading about the Shuttle-C for cargo and saving the liquid fuel tanks in holding orbits, I think that's a good idea. What prevents the addition of new modules to the ISS, Freedom, the International Space Station, every year? I think they are adding modules every year now. What's so great about the ISS's orbit that it is there? It's a sucky orbit, but it's there because the Russians demanded it -- it makes it easier for them to reach. Which I suppose is a good thing, since they're the only ones able to service it at the moment. Lunar Prospector was about first US moon mission since Apollo 17, then there's Clementine. Yep, and that's about it. Pathetic isn't it? But that should be changing now. I guess what I'm trying to figure out is if a mailbox full of cement was to be launched into lunar orbit, what would be its costs? Good question. I don't know the answer. But I suspect that once Falcon I flies, you could get your mailbox of cement plus the translunar injection booster into its payload, in which case, the launch would cost you $6M. Plus the cost of the booster and cement, of course. It seems pretty expensive to launch a payload into orbit. That's a problem with monopolies, although I guess it's a market economy, there are presumably some crazy regulatory controls on ballistic rocketry. Yes, all of that is involved, however this does seem to be changing, with several new and hungry launch companies getting ready for business (such as SpaceX for example). It's a lot easier to fantasize about thousands of launches per year than to design/build launching something to the moon. Too true! ,------------------------------------------------------------------. | Joseph J. Strout Check out the Mac Web Directory: | | http://www.macwebdir.com | `------------------------------------------------------------------' |
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Moon Base baby steps
"Ross A. Finlayson" wrote in message om...
I'm wondering about "lava tubes on the moon". I guess I was under the impression that besides Earth only Jupiter's moon Io had active volcanic activity, and I was thinking Luna was a cold chunk of rock. It used to be volcanic a long, long time ago. And it's been totally stable ever since, meaning those lavatubes are literally billions of years old. Only large meteorite impacts could destroy them, and they are bound to have randomly missed a few tubes. Yet, I read here that Luna has a molten, presumably iron, core, thus that it would have similar magnetic fields to Earth. Hardly! The Moon rotates at the rate of once a month as opposed to Earth's once a day. That alone would diminish the magnetic field greatly. But it's not even the rotation of the planet that's thought to cause the magnetic shield but convective forces in the Earth, causing magma to float around in circles. On the Moon there's hardly any seismic activity. It's rather cool on the inside. And it's tidally locked with Earth, making it even more inert, with anything deep down unlike- ly to move. -- __ "A good leader knows when it's best to ignore the __ ('__` screams for help and focus on the bigger picture." '__`) //6(6; ©OOL mmiv :^)^\\ `\_-/ http://home.t-online.de/home/ulrich....lmann/redbaron \-_/' |
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Moon Base baby steps
"Ross A. Finlayson" wrote in message om...
Geosynchronous orbit is much farther away than low Earth orbit, some 22,000 miles or something. 36,000km. Then, let's see, I think the moon is 600,000 (500-700) kilometers away, 384,400km. and Mars variously 20 million to 200 million. 54,511,000km to 401,356,000km. I was reading about the Shuttle-C for cargo and saving the liquid fuel tanks in holding orbits, I think that's a good idea. It would be an even better idea if that fuel could be supplied from them Moon, from where it's much, MUCH cheaper to launch. Only build- ing an industry mining oxygen on the Moon may be hard. The Moon's mass is 46% oxygen but extreme temperatures and/or chemical procedures have to be applied to release it. Focusing solar power to cause the temperatures can be achieved, but materials containing the ovens are a tough nut to crack. As for the chemicals, keeping them in a recycling loop is the tough part, because you couldn't get them on the Moon it- self. What prevents the addition of new modules to the ISS, Freedom, the International Space Station, every year? What's so great about the ISS's orbit that it is there? The lower, the cheaper, especially if you want to add a lot of mass. You launch it just high enough so it's safe from air friction. No one's had any ambition in the last thirty years to go any higher up into space than they absolutely had to. That was 550km for people and 36,000km for TV and radio satellites. Compare that to the distances above! But it's not quite as bad as it looks, considering gravity diminishes squared with distance. It's not as if there's ten times more energy needed for the Moon than for GEO. You're actually half the way there when you're in GEO, energy- wise. -- __ "A good leader knows when it's best to ignore the __ ('__` screams for help and focus on the bigger picture." '__`) //6(6; ©OOL mmiv :^)^\\ `\_-/ http://home.t-online.de/home/ulrich....lmann/redbaron \-_/' |
#29
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Moon Base baby steps
In article ,
Ross A. Finlayson wrote: I'm wondering about "lava tubes on the moon". I guess I was under the impression that besides Earth only Jupiter's moon Io had active volcanic activity, and I was thinking Luna was a cold chunk of rock. Nowadays, probably. But there is no question that it had extensive volcanic activity early in its history; indeed, there are geochemical hints that much of its surface was molten at one point. Lava tubes, miles long underground caverns similar to lava tubes on Earth, where higher temperature magma flowed out and left behind open space, would probably be among the major geologic reasons for their to be caverns on the moon with the lack of running water. I just had never heard of their existence before yesterday, and don't know of any on the moon itself. Hadley Rille, which Apollo 15 landed beside, is almost certainly a collapsed lava tube. (Lunar lava tubes can be *big*.) A few halfway- intact ones have been spotted in images taken by orbiters. Some of them show up as "dashed lines" -- the roof has fallen in on some parts but not other parts, which might be very convenient for getting into them. I think there should be shortly ten or fifteen satellites about the moon, these would be necessary for a variety of surface operations. I may be wrong, the moon has no appreciable atmosphere, thus no ionosphere and only line-of-sight radio communications. A satellite array would be critical in providing global (?) coverage of communications availability to surface operations. Indeed, there's no ionosphere, so radio is line of sight or nearly so. But you don't need a whole bunch of satellites. One near the Earth-Moon L1 point, and another in a "halo orbit" near the L2 point, will suffice initially. (Later on, it may be better to have larger numbers in lower orbits, to reduce transmitter power and speed-of-light delays, but that can wait.) The L1 satellite, in fact, can be postponed for a while in favor of using Earth stations for that role. I always why there weren't more air-boosted launches, an aerodynamic launch plane flies a hundred thousand feet high and the launch vehicle separates and boosts to orbit from high in the sky. It's a rare aircraft that can fly at 100kft. Half to a third of that is more typical. Air launch does have advantages, mostly for thinner air (neither the speed nor the altitude per se is very significant), but it also limits your rocket's mass to what your aircraft can carry, and even for a 747 that's fairly limited. I was reading about the Shuttle-C for cargo and saving the liquid fuel tanks in holding orbits, I think that's a good idea. What prevents the addition of new modules to the ISS, Freedom, the International Space Station, every year? What's so great about the ISS's orbit that it is there? The limitation on adding new modules is the cost of building them and launching them. The orbit is a rather complex compromise involving reachability from launch sites, minimum air drag, and maximum payload for launches. About mapping the lunar surface and within it, I wonder if ground penetrating radar instruments would be any good, for example for discovering lava tubes. Yes. This was done experimentally from lunar orbit on Apollo 17, although data analysis was difficult (then) and I'm not sure how much was learned. -- MOST launched 30 June; science observations running | Henry Spencer since Oct; first surprises seen; papers pending. | |
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Moon Base baby steps
"Ool" wrote in message ...
Compare that to the distances above! But it's not quite as bad as it looks, considering gravity diminishes squared with distance. It's not as if there's ten times more energy needed for the Moon than for GEO. You're actually half the way there when you're in GEO, energy- wise. Yeah, the concept of the mass driver, electromagnetic ramp launches, in the reduced gravity field of the moon with its lack of atmosphere is a good idea for filling an orbit and making a ring around the moon. The mass driver is the roller coaster that continually accelerates using electromagnetic motive force, the super-size railgun. I think it would take about a three mile track and large amounts of electricity on the moon, an Earth based mass driver would have to be much larger, although it would be much easier to construct in terms of various logistics. The mass driver to launch passengers would have to be much longer so that it could accelerate its payload more slowly. I think one of the key advancements required is the high-termperature superconductor. Also I wonder about nuclear powered satellites. Do they have those nuclear powered batteries? Cursory research is saying the lunar mass driver would have to be more along the lines of 60 kilometers in length, and that it's more of a coilgun than a railgun. The mass driver doesn't necessarily need a cart spinning around a track or send-and-retrieve, instead it could levitate mangetically the payload capsule and launch the whole thing. I read something that for safety reasons or dust or other items that could not penetrate Earth's atmosphere would be launched, but it seems that for just putting blocks into lunar orbit to form an orbital platform could happen quite safely because the launch parameters will have to be very precisely controlled. Hey about the distance to the moon, that seems kind of near. Don't get me wrong, it takes a day just to drive a thousand kilometers at the speed limit. Moon is big in the sky. It costs six million dollars to send a mailbox full of cement to lunar orbit? I guess mass production of satellites and all-terrain space rovers is just like the mass production of anything else, purchase in bulk of non-unique items lowers costs and specialized manufacturing processes further lowers costs, where systemic quality controls ensures reliability. As well, a lot goes into the systems to guide and direct the paths of these items launched into space, that scales up pretty rapidly because of the systems to determine orbits, with the past, current, and future locations of destinations, until there is a chart with which fuel module and scientific ballast to add to each of hundreds of otherwise identical payloads, then download the firmware into the prom, button it up, put it in the modular payload module, and ship it to the launch booster assembly site. Once anything is out of Earth orbit, it can basically be destined to any other location in the solar system. It takes various amounts of time to get there, but a time capsule could be launched to land on the moon in five hundred years, with minimal corrections. That of course demands extremely precise orientation systems, thus to apply acute bursts or continuous steering through extremely low or zero reaction mass propulsion. I think the gyroscope provides the orientation reference, or laser pointing to beacons, I guess, I don't know. Can anyone please point me to maps of the Moon and Mars with the geographic regions labelled? I hear about the Eridiana Planum and wouldn't know it from some other feature or named area of Mars or Luna. http://www.penpal.ru/astro/ For Luna, it looks like the small impact craters are called craters, and the large ones, seas. http://ic.arc.nasa.gov/ic/projects/b...up/Atlas/Mars/ The lunar rovers should be these remarkably robust things, wheeled, you know, like a lunar rover, with their own solar charging panels as they are probably not nuclear powered, semi-autonomous, solid state in design, with various modular attachments. One idea is that they are cooperative in that one could recharge another through the modular inductive power couplings, so if one ran out of power in the shade another could go salvage it. The could also be modular in that for example some could just carry bulk materials form place to place while others might have robot arms for telepresence. As well, they should be modular so that if a part goes bad one of the other ones could actually refit it in the field. The rovers should be in near-constant use, for example with the rover-mobile driving around to schools on Earth so kids could teleoperate the rovers, or just a web page. Of course, they'd leave a bunch of tracks, which in Luna's lack of erosive water and wind would last for many hundreds of years, leading to various attempts to write things on the surface of the moon, in the rover sandboxes. It seems like the satellite array for communications and also for remote sensing would be a good idea. Then, the rovers wouldn't need as powerful of communications gear necessary to broadcast to Earth, instead they can broadcast to the satellites which then interlink and then downlink back to the lunar rover base stations. The idea of the base stations is as solar and/or nuclear powered fixed installations with communications relays to the satellite array and to Earth, and the ability to recharge the rovers. The main Earth communication link could be located where it has good reception with Earth. These of course are all unmanned and rudimentary in their ability to repair themselves, thus they should be designed with long lifespans, because the manned settlements will almost surely be busy repairing their own systems. Mars, besides its distance, seems better on most counts for settlement and colonization than the moon. In the absence of FTL travel to millions of primeval Earth-like worlds, Mars is kind of like living in the desert. In terms of mining, I still think the asteroids are where it's at: some are just huge chunks of precious metals. Yeah there is a lot of information about lava tubes. http://www.oregonl5.org/lbrt/l5lbi88.html Have a nice day, Ross F. |
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