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Once We Have A Self Sustaining Mars Colony - Then What?
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#43
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Once We Have A Self Sustaining Mars Colony - Then What?
In article ,
lid says... On 16-12-15 13:15 , Jeff Findley wrote: In article , says... In article . com, says... So I am not advocating that the garbage ship lower its circular orbit, I am advocating that it transform its circular orbit into highly elliptical one. And in that case, would the delta-V requirement be significantly lower ? I know what you're proposing. I took the 500 level Orbital Mechanics class in college. This whole "waste disposal in the sun" idea might have even been a class exercise just to show how ludicrous it is since it's not a difficult calculation. You need to RUN THE NUMBERS. When you do, you'll see that the delta-V is so high that this idea is just not economically viable. Since you're so lazy as to not even attempt a Google search, here is a link to a "delta-V map of the solar system". Sure, there are lots of simplifying assumptions behind the numbers, but it's a good starting point for someone when they really have no clue how much it costs to go, well anywhere, in the solar system. http://i.imgur.com/SqdzxzF.png The way this works is you add up the numbers along the path from "Moon" to "Low (earth) Orbit" to get the approximate delta-V the Apollo CSM used to get from lunar orbit back to earth. Now, add up all the numbers along the path from "Earth" to the "Sun". See the huge difference between the numbers? Well, there's your problem with "sun disposal"! That map seems not directly relevant to garbage disposal in the Sun. It shows something like 600 km/s to reach the Sun, but I'm pretty sure that if we get the garbage off Earth (11 km/s) and stop its circum-solar orbital velocity (30 km/s more), it will fall into the Sun. The 600-odd km/s in the map is probably for *landing* softly on the Sun -- perhaps "landing" isn't the right word, so let's say "reaching a point at the Sun's visible photosphere, at rest with respect to the photosphere". Of course 41 km/s is still a rather large delta-v. Here's another chart which may be more accurate (scroll down towards the bottom): https://en.wikipedia.org/wiki/Delta-v_budget This just about matches your math. So, yes, using this other chart the answer is somewhere on the order of 40 km/sec to go from earth's surface into the sun. This is 4x the cost of getting to LEO. It's still more than twice the delta-V compared to what it takes to get from the earth's surface to the moon's surface. Jeff -- All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of. |
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Once We Have A Self Sustaining Mars Colony - Then What?
William Mook wrote:
On Friday, December 16, 2016 at 9:42:54 AM UTC+13, Fred J. McCall wrote: William Mook wrote: On Tuesday, December 13, 2016 at 9:37:17 AM UTC+13, JF Mezei wrote: On 2016-12-12 13:29, Fred J. McCall wrote: The Moon is better suited to that sort of thing, but it's still hideously expensive trash. Water is far more abundant on Mars than the Moon, but for 900,000 litres per day, we can likely find a place on the Moon to mine for water - and send part of it to Earth for consumption there. The problem with the moon is we don't have iron or carbon dioxide readily available to make return capsules or water bottles from. We do on Mars. Nobody but you is talking about shipping water back, Mook. Water is too valuable where it is to ship it back to Earth, which has stupid amounts of fresh water. Then you add in the shipping costs and it's a REALLY dumb idea. Someone asked the question, I analysed it. Nobody 'asked the question'. You brought this stupid idea up all on your own. What someone thinks is dumb or not doesn't determine the profitability of a business. It does when they think it's dumb because of the costs involved. Would people buy water bottled on Mars at some price? Yes. How do we know that? People ship water from Iceland to California and pay $2.22 per litre for the privilege. 900,000 litres per day is being shipped from an Icelandic glacier to all points around the world at this price - and a rather large business exists. ON Mars, sure. On Earth from Mars? Don't be preposterous. How close is the cost of shipping a tonne of water from Iceland to a million dollars? Hint: Not very. MookSpew of Magic Mookie Math Munched -- "Ordinarily he is insane. But he has lucid moments when he is only stupid." -- Heinrich Heine |
#45
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Once We Have A Self Sustaining Mars Colony - Then What?
On 16-12-16 13:20 , Jeff Findley wrote:
In article , lid says... That map seems not directly relevant to garbage disposal in the Sun. It shows something like 600 km/s to reach the Sun, but I'm pretty sure that if we get the garbage off Earth (11 km/s) and stop its circum-solar orbital velocity (30 km/s more), it will fall into the Sun. The 600-odd km/s in the map is probably for *landing* softly on the Sun -- perhaps "landing" isn't the right word, so let's say "reaching a point at the Sun's visible photosphere, at rest with respect to the photosphere". Of course 41 km/s is still a rather large delta-v. Here's another chart which may be more accurate (scroll down towards the bottom): https://en.wikipedia.org/wiki/Delta-v_budget This just about matches your math. So, yes, using this other chart the answer is somewhere on the order of 40 km/sec to go from earth's surface into the sun. This is 4x the cost of getting to LEO. It's still more than twice the delta-V compared to what it takes to get from the earth's surface to the moon's surface. That's an interesting Wikipedia page, thanks. It also contains this sentence, about reaching the Sun from LEO, which would normally take 24 km/s according to their table: "One can use 8.8 km/s to go very far away from the sun, then use a negligible Δv to bring the angular momentum to zero, and then fall into the sun." So about 11 km/s in total should suffice, just as Alain Fournier said, but this plan (go far, then stop and fall) seems even practical. One could perhaps get a nudge from Jupiter, on the way, if needed. -- Niklas Holsti Tidorum Ltd niklas holsti tidorum fi . @ . |
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Once We Have A Self Sustaining Mars Colony - Then What?
On Saturday, December 17, 2016 at 12:01:48 AM UTC+13, Jeff Findley wrote:
In article . com, says... On 2016-12-15 06:15, Jeff Findley wrote: http://i.imgur.com/SqdzxzF.png See the huge difference between the numbers? Well, there's your problem with "sun disposal"! These numbers are for circular orbit around sun. Notice no "red arrow" to indicate one could use the sun to slow down to orbital speed of 0. Actually, the number between the "low sun orbit" and the sun is exactly what you need in order to send something directly into the sun. Is that true? Well, if we calculate a Hohmann transfer orbit between 1 AU and 1/1075 AU vs Earth orbital velocity (29.765 km/sec) dropping to so... we have for that orbit a = (1 + 1/1075) / 2 = 0.50045612... Applying the Vis Viva Equation; V = SQRT( 2/1 -1/0.50045612) = 0.04269446 Which is 1.270833 km/sec at 1 AU (Earth's orbit) So, instead of escaping Earth with 29.765 km/sec hyperbolic excess velocity we only have to escape with 28.49417 A difference but not much of one. On the Earth's surface you must depart with V = SQRT(11.19^2 + 29.77^2) = 31.81 km/sec (71,120 mph) to hit the Sun dead centre vs V = SQRT(11.19^2 + 28.50^2) = 30.62 km/sec (68,460 mph) to graze the corona, burn up and fall in to the sun. A slight but definite change. Yes, you can save a bit if you "graze" the sun over many orbits, There's very little advantage in doing it over several orbits. Look at the density of the solar atmosphere vs altitude, and lower the perigee so it definitely burns up. There is no advantage in doing it over several orbits. There is a definite though slight advantage in having the payload graze the solar atmosphere. but that is not desirable when trying to "dispose" of nuclear waste since your disposal "capsule" could break apart during one of the passes spewing waste back into the solar system. Then doing it at all is problematical since your capsule could spew waste during launch, transfer or any other time. Fact is if you escaped the gravity well of Earth, and spewed the most intense radioactive waste imaginable into interplanetary space, it would fall below detectability in a matter of days. You *really* want the stuff to go into the sun directly rather than by any other means. https://www.researchgate.net/publica..._Astrodynamics http://fgg-web.fgg.uni-lj.si/~/mkuha...white-1971.pdf Get these book - read them - and then we can talk. Shooting a payload off Earth and letting it fall directly into the sun by zeroing out Earth's orbital velocity is materially not different than ALMOST zeroing out Earth's orbital velocity and letting it graze the upper reaches of the solar disk at an altitude that assures complete disposal. Again, look how *big* the sum of the numbers are to go from the earth's surface *into* the sun. There is a definite but slight difference in velocities - of about 1.27 km/sec. Would it be correct to state that orbital energy of a circular orbit of X altitude could be equal to that of an elliptical orbit where perigee is much lower than x, and apogee is much higher than x ? You need to find an orbital calculator (you can find them online) and play with it. It's much too early in the morning and I've not head enough coffee today to work up the motivation to do this for you. Jeff You can calculate all this quite readily. Another approach would be to boost a waste capsule to a very high aohelion above the sun and then reduce velocities to nearly zero at apohelion for a sun grazing orbit that assured complete capture at that solar altitude. dV to 0 out tot km/s AU Time yrs 29.77 - 29.77 1.00 0.18 Earth 17.19 4.60 21.79 2.00 1.42 12.15 6.69 18.84 3.00 2.33 Asteroids 9.41 7.89 17.30 4.00 3.39 7.69 8.66 16.35 5.00 4.58 4.01 10.37 14.38 10.00 12.04 Outer Planets 2.72 10.99 13.71 15.00 21.58 2.05 11.31 13.37 20.00 32.82 1.65 11.51 13.16 25.00 45.53 1.38 11.64 13.03 30.00 59.56 1.19 11.74 12.93 35.00 74.79 1.04 11.81 12.85 40.00 91.13 Kuiper Belt 0.93 11.87 12.79 45.00 108.52 0.83 11.91 12.75 50.00 126.89 0.42 12.12 12.54 100 356.21 0.04 12.31 12.35 1,000 11,188.74 So, you can see that by boosting to a large apohelion and then slowing at that apohelion slightly, you can drop right into the Sun, with very little delta vee - about half or less of the delta vee of a direct descent into the Sun. The only penalty you pay is the time it takes to complete the mission. Now a gravity boost around Jupiter has the potential to kick a passing spacecraft by about Jupiter's orbital velocity - which means that boosting to Jupiter and using gravity assist to zero out the spacecraft's speed - saves delta vee. This reduces the total delta vee required from 15.24 km/sec to 9.61 km/sec! 5.63 9.61 15.24 7.00 7.27 Jupiter This is the least energy cost path to Jupiter. It takes 7.27 years to carry it out. It takes 4.0 years to get to Jupiter from Earth along a minimum energy transfer orbit, and another 3.27 years for an object to fall into the Sun after Jupiter's zeroed out its speed. You will recall that a gravity assist maneuver is like hitting a baseball with a baseball bat. Relative to the bat, the ball leaves with slightly less velocity than with which it hit the bat. However, if the bat is moving, the speed of the ball relative to the ball part is consierably changed. Same here. Jupiter is moving relative to the Sun, and by arriving at the right angle and departing at the right angle, the spacecraft velocity relative to the Sun is zero'd out - and the spacecraft falls directly into the Sun. This by the way is the path Solar Probe Plus will use to travel to the Sun in 2018 http://spaceflightnow.com/2015/03/18...f-solar-probe/ -- All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of. |
#47
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Once We Have A Self Sustaining Mars Colony - Then What?
On Tuesday, December 13, 2016 at 11:35:53 AM UTC+13, Rick Jones wrote:
JF Mezei wrote: It is hideously expensive to launch spent radioactive garbage and have it crash onto the moon (there is no need to land, is there ?) compared to all the regulatory red tape and long term costs of maintaining uranium dump site on earth ? There is a non-trivial group of folks who fight transporting nuclear waste by either road or rail. It seems rather unlikely they would find launching it into space any more palatable. Case in point, the folks who protest any launch involving RTGs. rick jones -- It is not a question of half full or empty - the glass has a leak. The real question is "Can it be patched?" these opinions are mine, all mine; HPE might not want them anyway... feel free to post, OR email to rick.jones2 in hpe.com but NOT BOTH... https://www.youtube.com/watch?v=R86mkvU4qHw http://www.tandfonline.com/doi/abs/1...nalCode=rbul20 http://www.larouchepub.com/eiw/publi...38-40_3833.pdf Moving these processes off-world and using the Moon, Mars and major dwarf planets like Ceres and Vesta, for raw materials - allows us to raise living standards generally whilst reducing our reliance on the biosphere lowering costs and end war. Aluminium - (Deville process, Bayer process, Hall-Héroult process, Wöhler process) Ammonia, used in fertilizer & explosives - (Haber process) Bromine - (Dow process) Chlorine, used in chemicals - (Chloralkali process, Weldon process, Hooker process) Fat - (Rendering) Fertilizer - (Nitrophosphate process) Glass - (Pilkington process) Gold - (Bacterial oxidation, Parkes process) Graphite - (Acheson process) Heavy Water, used to refine radioactive products - (Girdler sulfide process) Hydrogen - (Steam reforming, Water Gas Shift Reaction) Lead (and Bismuth) - (Betts electrolytic process, Betterton-Kroll process) Nickel - (Mond process) Nitric acid - (Ostwald process) Paper - (Pulping, Kraft process, Fourdrinier machine) Rubber - (Vulcanization) Salt - (Alberger process, Grainer evaporation process) Semiconductor crystals - (Bridgeman technique, Czochralski process) Silver - (Patio process, Parkes process) Silicon Carbide - (Acheson process, Lely process) Sodium carbonate, used for soap - (Leblanc process, Solvay process, Leblanc-Deacon process) Sulfuric acid - (Lead chamber process, Contact process) Titanium - (Hunter process, Kroll process) Zirconium - (Hunter process, Kroll process, Crystal bar process, Iodide process) https://www.nap.edu/read/12028/chapter/5 In a little more than 50 years, the global economy grew from $7.1 trillion to $56 trillion in constant dollars In 2002, 1.12 billion households—about three quarters of humanity—owned at least one television set. There were 1.1 billion fixed phone lines in 2002, and another 1.1 billion mobile lines. The Internet now connects about 600 million users. By 2050 population grows to 8.9 billion people, with nearly all of this growth in developing countries. The United States, with less than 5 % of the global population, uses about a quarter of the world’s fossil fuel resources—burning up nearly 25 % of the coal, 26 % of the oil, and 27 % of the world’s natural gas. As of 2002, the U.S. had more private cars than licensed drivers. This means - the average American consumes 5.0x coal 5.2x oil 5.4x natural gas 6.4x water (159 gallons/day) 2.0x Chicken: 84.9 pounds 2.0x Beef: 63.5 pounds 2.0x Pork: 48.2 pounds 2.0x Turkey: 17.5 pounds 2.0x Lamb and Mutton: 1 pound New houses in the U.S. were 38 % bigger in 2002 than in 1975, despite having fewer people per household on average. The USA imports 100% of these materials 100% Arsenic Asbestos Bauxite and Alumina Columbium (Niobium) Flourspar Graphite Indium Manganese Mica Quartz Crystal Rare Earths Rubidium Strontium Thallium Thorium Vanadium Yttrium 90% to 100% Gallium Gemstones Bismuth Platinum 80% to 90% Stone (dimensioned) Antimony Rhenium Tantalum Barite Diamond Palladium Cobalt Potash 70% to 80% Tin chromium Titanium (sponge) Iodine Titanium concentrates 60% to 70% Tungsten Silver Zinc ickel Silicon (ferrosilicon) 50% to 60% Peat Magnesium Metal Garnet (industrial) Magnesium compounds Diamond (dust, grit and powder) 40% to 50% Aluminum Ammonia Copper 30% to 50% Perlite Vermiculite Mica (scrap flake natural) 20% to 30% Cadmium Gypsum Sulfur Cement Iron and Steel 10% to 20% Salt Pumice Talc 1% to 10% Iron and Steel Slag Phosphate Rock Iron Ore Lead Lime Sand and Gravel (construction) |
#48
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Once We Have A Self Sustaining Mars Colony - Then What?
On Friday, December 16, 2016 at 8:30:29 AM UTC+13, JF Mezei wrote:
On 2016-12-15 06:05, Jeff Findley wrote: expensive to do this due to the huge delta-V needed. All the hand waving in the world won't change the laws of physics, so stop waving your damn hands. Not asking to wave the laws of physics. Asking to understand in simple words how returning from the moon is the same as de-orbiting from ISS (aka: decelerate orbital speed around earth to drop altitude). Here is a different question: When Apollo 13 ended its slingshot around the moon, what direction was it going ? towards earth ? or against orbital speed of moon going around earth to lower its orbital speed around earth ? Or did it aim "diagonal" to essentially follow a curve ball trajectory such that it initially aims "behind" the Earth, knowing that its orbital speed will accelerate as it drops altitude so would catch up with Earth ? When Apollo 13 did a burn midway in its return, what direction was it burning towards ? Earth ? or again, against its orbital velocity around earth ? Atmospheric Entry Overview https://www.youtube.com/watch?v=aW5ozq4Tqew Lunar Travel Overview https://www.youtube.com/watch?v=lEgA16upX9c Quaternions an Introduction https://www.youtube.com/watch?v=3BR8tK-LuB0 https://www.youtube.com/watch?v=ISbJ9S0fzwY Quaternion fun https://www.youtube.com/watch?v=jlskQDR8-bY https://www.youtube.com/watch?v=UaK2q22mMEg Astrodynamics http://fgg-web.fgg.uni-lj.si/~/mkuha...white-1971.pdf |
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Once We Have A Self Sustaining Mars Colony - Then What?
On Dec/16/2016 at 8:33 PM, JF Mezei wrote :
Question: For a Progress: if it fires de-orbit engine staight down towards Earth, could it graze atmosphere with less fuel than a proper "de-orbit" where its orbital velocity is decreased ? No that would use more fuel not less. (Since Progress is meant to self destruct during re-entry, the fact that re=entry would be at higher speed and higher G forces is not relevant). Question: When Progress does a proper de-orbit burn, is the resulting orbit one where apogee is same as former circular orbit, but perigee is lower ? Yes. Is it correct to state that if it aims straight down, the resulting orbit is one where perigee is lower but apogee will be higher than former circular orbit ? Yes that is what would theoretically happen if they did such a thing, they don't. Alain Fournier |
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Once We Have A Self Sustaining Mars Colony - Then What?
On Thursday, December 15, 2016 at 5:19:54 PM UTC+13, Fred J. McCall wrote:
William Mook wrote: On Tuesday, December 13, 2016 at 12:17:14 AM UTC+13, Jeff Findley wrote: We've got a Mook on Mook on Mook reply here (minus the first two Mooks)... In article , says... The sands of Mars are red. That's because they're made out of hematite. Why wouldn't you mine iron there and send it back to Earth with a rail gun? Because steel made on earth is already quite cheap, so it would be economic suicide to do what you propose. Steel has been cheap historically, but is rising inexorably as raw materials are depleted here. https://www.bloomberg.com/news/artic...-s-rapid-shift Pretty sure it's never going to exceed a million dollars a tonne, So? so it's always going to be cheaper to do it here than to bring it back from space. Hahaha - bootless speculation indeed. You *always* and I mean *always* accuse others of precisely the thing you do! lol. Sheez. The sensible thing to do with space resources is, well, space stuff. A false dilemma is a fallacy that involves a situation in which only limited alternatives are considered, when in fact there are additional options. The obvious additional option here is that someone with a planetary desert deep in hematite and the ability to turn it to steel, might find ways to seek clients beyond the ones they're already serving! lol. Put differently, when all the space stuff needs are met, and there's more resources available, those resources will naturally find their way to other uses. There is in fact no reason to believe terrestrial customers are special. Earth's surface after all resides in space. Krafft Ehricke in 1962 detailed how this would occur in the last half of the 20th century; https://www.youtube.com/watch?v=R86mkvU4qHw Element---- Fuel Non Fuel Mars Soil Multiply Carbon---- 0.3551 0.0574 Hydrogen-- 0.0763 0.0025 Silicon----- 0.1355 0.2444 0.1725 1.4169 Oxygen---- 0.2217 0.4547 0.5440 0.8358 Iron------- 0.0797 0.0479 0.1042 0.4598 Aluminum- 0.0039 0.0023 0.0241 0.0955 Magnesium 0.0013 0.0017 0.0422 0.0403 Copper---- 0.0033 0.002 Manganese 0.0057 0.003 Calcium--- 0.0473 0.1417 0.0472 3.0018 Sodium--- 0.0158 0.0095 0.0074 1.2800 Sulfur----- 0.0095 0.0058 0.0212 0.2732 Potassium 0.0036 0.0021 0.0021 1.0123 Phophorus 0.0032 0.0019 Chlorine-- 0.0244 0.0147 0.0070 2.1000 Mars soil has plenty of all the things Binney estimates the US economy needs. Launching materials back to Earth via a rail gun or magnetic launcher could be done very cheaply. Besides, one would think that a Mars colony would use such raw materials to either build things they need on Mars or build things that are actually worth exporting. That's a false choice. In order to use or build things on Mars local steel is needed. So Martians would need to supply themselves with steel made from hematite on the surface and carbon in the carbon dioxide in the air - which means any surplus to their needs could be exported. Except no one would buy it at the prices they'd have to charge. You're the one making baseless assertions. Krafft Ehricke did studies for General Dynamics in 1962 that showed Mars could be a competitive source for nearly all materials we mine on Earth today. Gerard K. O'Neil showed the Moon could build orbiting colonies at Lagrange Points in the Earth Moon system and they would make solar power stations to beam energy to Earth at costs that would make power too cheap to meter in 1972. Raw materials aren't going to cut it as an export unless there is a return on that investment. Correct. Prices are rising on Earth and Earth's ability to produce low cost steel will be non-existant in 64 years according to the experts. Some believe shortages may be arriving in as little at 12 years. It's always going to be cheaper to do it here No it isn't, especially since nuclear fission can be used to make power too cheap to meter in an environment blanketed with deadly radiation and served by artificial intelligence all things will be too cheap to meter. Earth will be a natural place to send things. Especially since its easy to launch things off mars with a magnetic launcher. once you factor in transport costs. You've obviously never heard of mass drivers and non rocket launchers. With Mars' low gravity and low atmospheric density, it is a natural choice to send products back to Earth. It's why there will be a local steel industry on Mars; because it costs too bloody much to bring it from Earth. It will be cheaper to make steel on Mars than on Earth in the first place because of the super abundance of hematite (iron makes Mars red) and the super abundance of energy - due to the ability to use nuclear fission in ways that make it too cheap to meter, and the super abundance of labour due to the widespread use of AI and robotics. http://journals.lww.com/asaiojournal...cial.9 6.aspx http://www.osti.gov/scitech/servlets/purl/805252= https://www.researchgate.net/profile...7583975b89.pdf http://spectrum.ieee.org/automaton/r...cs-atlas-robot Sorry Mook, I feel your love. Keep your hands to yourself! Haha - always misinterpreting - never getting it right. but this entire idea is b.s. No it isn't. Yes it is. No it isn't. Think about the transportation costs. Okay Get back to me when the price of steel on Earth exceeds a million dollars a tonne and we can start thinking about it. Nonsense. You have prejudices only. Its obvious when power and labour are too cheap to meter, and your sitting in the metal of a desert made of iron - that you will make iron and sell it to those who want it. At 40 GJ per ton to reduce it from hematite and 16 GJ per ton to launch it to Earth on a mass driver - using nuclear fission technology that's 70 years old TODAY - with no worries about radiation and the environment - iron will arrive from Mars more cheaply than its made on Earth TODAY - with zero environmental costs. I don't know how you got to visions of Mars colonies sending quite common raw materials like iron, silicon, aluminum, and etc. to earth by railgun, but it's just not going to be viable economically. That's your problem that you don't know something. Perhaps if you listened to those who know more than you - that might help. Great advice. One wishes YOU would take it once in a while. I do. That's why I'm able to point to peer reviewed literature for EVERYTHING I say. You? Not so much! More below. Nope. Dumping the Magic Mookie Multiplication Math. Massive MookSpew Munched See? You ignore your betters. I guess that's one coping mechanism for you.. -- "Some people get lost in thought because it's such unfamiliar territory." --G. Behn |
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