https://lunarpedia.org/api.php?action=feedcontributions&user=209.23.189.25&feedformat=atomLunarpedia - User contributions [en]2024-03-29T06:25:58ZUser contributionsMediaWiki 1.34.2https://lunarpedia.org/index.php?title=Talk:Luna-Mars_Trade&diff=13963Talk:Luna-Mars Trade2008-11-06T17:19:10Z<p>209.23.189.25: fixing typo</p>
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<div>All of the processes necessary for Luna-Mars trade are not sketched in any great detail, but it seems worth considering. If a mass accelerator can boost the supersonic landing Mars to low Mars orbit vehicle mentioned up to 1025 meters per second, then 49% of the take-off weight gets to orbit.--'''FARTHERRED'''11:28pm Central Standard Time 31 October 2008 <br />
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Does the original creator realize that by inserting a slash in the article name, he has created a sub-article of [[Luna]]? - [[User:Jarogers2001|Jarogers2001]] 07:09, 1 November 2008 (UTC)<br />
<br />
:Problems like that can be avoided if we disable subpages for mainspace articles. I believe Wikipedia has done this. However, it might be a better idea for Lunarpedia if we keep subpages for mainspace articles. In that case, I suggest moving the content to "Luna-Mars trade". [[User:T.Neo|T.Neo]] 07:41, 1 November 2008 (UTC)<br />
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::Moving it was my thought as well. I rather like subpages. Any objections to a move? - [[User:Jarogers2001|Jarogers2001]] 16:14, 1 November 2008 (UTC)<br />
*Aw shucks. It says right here on my Wiki Reference Card not to use slash, plus sign, number sign, or any of a number of kinds of brackets in a title. I did not have the reference card with me at a distant location but probably would not have consulted it anyway. This is one way to learn. I hope it is not too much trouble to move the article.--[[User:Farred|Farred]] 16:36, 1 November 2008 (UTC)<br />
:It can be moved just like any other article. There is no additional procedure. - [[User:Jarogers2001|Jarogers2001]] 03:53, 2 November 2008 (UTC)<br />
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:::If we disable it, we should also disable it for the seldom used GFDL namespace and the never used CC_Luna namespace, as they have teh same function as the main namespace, just not public domain. -- [[User:Strangelv|Strangelv]] 18:18, 1 November 2008 (UTC)<br />
::::I see no reason to disable it at this time. I intend to use sub-articles in the future. - [[User:Jarogers2001|Jarogers2001]] 03:53, 2 November 2008 (UTC)<br />
*Why should a Mars to low Mars orbit vehicle have wings and land supersonic? The wings should allow the vehicle to kill its orbital velocity through aerodynamic drag when returning to Mars and lift from the wings should allow the vehicle to set down gently on a runway. The orbital speed being considered is only about 40% faster than the SR-71 flew, and the Mars to low Mars orbit vehicle would only move through the atmosphere at that speed for a short time while reentering from orbit. If the SR-71 could tolerate 2450 meters per second for thousands of miles of flight, a Mars to low Mars orbit vehicle should be able to tolerate flying at 3440 meters per second through Mars' upper atmosphere for a few minutes. The vehicle would not move at orbital velocity when touching down on a runway, but it would still need to be supersonic to generate enough lift for a gentle landing.--[[User:Farred|Farred]] 02:47, 4 November 2008 (UTC)<br />
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A lifting reentry for martian cargo is an interesting idea. I have always contemplated capsule type landings. However, I am a bit skeptical about a supersonic landing. If I am correct, supersonic on Mars is faster then on Earth due to thinner air. And, even in the thinner air, any landing gear being deployed would have to resist this force. Add to that what the gear would encounter on contect with the ground, and I don't see a happy landing. To lower the landing speed, one would have to increase the lifting force. Maybe swing wings would work, they will incease compexity.<br />
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How is the shuttle launched from the Martian surface? Is it a vertical or horizontal launch? [[User:T.Neo|T.Neo]] 07:53, 4 November 2008 (UTC)<br />
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*In the case of the speed of sound T.Neo's memory serves falsely. The speed of sound is dependent directly on the temperature and inversely on molecular weight, but it is nearly independent of pressure. The suggested shuttle would take off vertically for the version that puts 36% of take-off weight into orbit. It would be thrown into the atmosphere near the peak of mount Olympus at 1025 meters per second in the version to be boosted by electric acceleration which is suggested to achieve 49% of take-off weight to orbit. SSTO is a less demanding challenge for Mars than for Earth. --[[User:Farred|Farred]] 14:42, 5 November 2008 (UTC)<br />
::Woa. I thought that the speed at which sound propagates is dependent upon the density of the medium, not the temperature. - [[User:Jarogers2001|Jarogers2001]] 19:00, 5 November 2008 (UTC)<br />
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SSTO is definatly much easier on Mars then on Earth.<br />
What is the speed of sound on Mars? What would the landing speed for the shuttle be? WHat kind of forces would the landing gear endure? What would the heat sheild of such a craft be made of? [[User:T.Neo|T.Neo]] 16:07, 5 November 2008 (UTC)<br />
*I will return to the speed of sound on Mars later. For now I was thinking of a titanium steel Aerodynamic shell with heat soak on reentry and an insulated internal compartment for electronics with evaporative cooling using dry ice. Landing gear would be skids with an expendable layer.--[[User:Farred|Farred]] 16:29, 5 November 2008 (UTC)<br />
*The speed of sound on mars at about 0 C is about 240 m/sec making the low orbit velocity about mach 14.2 and and the contemplated electricly accelerated boost about mach 4.2 --[[User:Farred|Farred]] 19:22, 5 November 2008 (UTC)<br />
*I can see how Jarogers2001 might think that the speed of sound is dependent on density since sound travles faster in steel and in water than in air at room temperature. However, we are talking about just the atmosphere of Mars here, so the speed of sound is the square root of the quantity of the specific heat ratio times the gas constant times the temperature devided by the molecular weight quantity closed. That can be rewritten as a function of density, but that would seem an unneeded complication.--[[User:Farred|Farred]] 20:08, 5 November 2008 (UTC)<br />
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Titanium-steel thermal soak confuses me. Thermal soak is when an insulating substance keeps heat away from the airframe. Titanium-steel seems more like a radiative heatshield, where excess heat is radiated away, like the shuttle RCC. However, the problem with the shuttle RCC (And, presumably Titanium-steel) is that they are as good at conducting heat as they are radiating it. This means that the Titanium-steel will conduct heat to the rest of the ship. Not only does the computer need to be cooled, but systems to deploy the landing gear, the RCS, the MEs, etc. Add to that, whatever payload you are carrying might not like being heated up too much. Since the methane (and LOX) tanks take up a lot of space, it might be better to make the upper hull out of thinner material, possibly aluminium.<br />
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Considering where this craft would be working, and the stresses it endures on the way down, it would have to be pretty robust. It needs a minimal use of electronics, and must be maintainable with substances found on Mars. Nothing like the current space shuttle. Think of an aircraft operating out of the Siberian tundra. It must be very robust, like many russian aircraft. [[User:T.Neo|T.Neo]] 20:43, 5 November 2008 (UTC)<br />
*Sorry about “titanium steel.” That shows that I am not very familiar with titanium alloys. Try Grade 6 titanium alloy, containing 5% Aluminum and 2.5% Tin. Perhaps Grade 5 or Grade 9 would be better. I do not feel capable of making a final determination of alloy, but it isn’t going to be simple aluminum. It seems that I have heard of some heat resistant aluminum based alloys, but I can not name a good candidate at the moment. <br />
*As far as cargo heating is concerned, this thing takes cargo up for shipping exports. It comes down empty. That is when the heat threat is a worry. The landing skids are constantly deployed. They are part of the airframe, like ventral fins. The flaps are operated by heat resistant cables. The control motors are in the same insulated box as the electronics. A section of the air frame with the cross section reducing from fore to aft will not have such serious heat threat problems. The reaction control nozzles can stick out there. Any unused reaction control fuel can be dumped once the flaps bite. What are “MEs?” <br />
*I am not familiar with what you mean by heat soak, but the vehicle I describe would just soak up the heat and get hot. The idea is that the exposure to maximum heat threat will be short enough that it will not melt. <br />
*Minimizing the use of electronics would not make the craft more rugged. Electronic components can keep going for decades. Electronics are light enough that spare boards can be shipped with the craft without significant extra expense. Anything that fails can be swapped out. That is Siberia level maintenance. The electronics are necessary for this thing to work. <br />
*Since I am not an aeronautical engineer, I put only limited faith in my own suggestion, but nothing written here so far seems like a serious objection. --[[User:Farred|Farred]] 22:15, 5 November 2008 (UTC)<br />
*I can only roughly guess what speed would be necessary for landing. I guess 1000 miles per hour. That is about mach1.9 on Mars. There is reason for thinking the thermal threat will not be too great. Besides there being only 20% of the energy per pound of reentering spacecraft as there is on Earth, the carbon dioxide atmosphere heats up to a lower temperature for any given amount of heat it absorbs because carbon dioxide is triatomic. Also since carbon dioxide is half again as heavy as the average air molecule, for any given temperature the average carbon dioxide molecule is moving only about 82% as fast as an average air molecule at that temperature. This means that carbon dioxide does not transfer heat as effectively to the skin of a supersonic aircraft as air does. The point of my greatest uncertainty is whether or not the craft can maintain orientational control while supersonic in ground effect. This is an almost completely untested area.<br />
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Pity it only takes cargo on the way up. If I wanted to export anything from the martian system it would probably be mined from Deimos or Phobos. <br />
Landing large cargo on Mars is very tricky. Plans like Mars direct and Mars for less neglect landing. <br />
The Mars Science Laboratory will land with A "skycrane" system. However, this may not hold up well to <br />
sustainability. Is there any way this could be reconfigured for payload delivery to the Martian surface?<br />
Modularity is a good idea. Anything that cannot be made on Mars should be brought from Earth. For example, the MEs (Main Engines, sorry.) will be quite complex. If one breaks, a new one could be delivered from Earth, and just "dropped in". Same with electronics.<br />
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What would the maintainance effort? And what about turnaround time? [[User:T.Neo|T.Neo]] 08:57, 6 November 2008 (UTC)<br />
*The supersonic landing Mars to low Mars orbit shuttle (MTLMOS) concept is just that, a concept. Taking cargo down to Mars would increase the mass of the shuttle and therefore the thermal threat, but I can not produce the numbers that would say that this is possible or that it is not. Just working out the shape of the supersonic airframe, its center of gravity, and control parameters would be quite a task. If someone does that, they might say, “Yeah, we can take a little cargo on the downward leg.” They might say, “We tried but we just can not make it work. It always goes wild on the runway before touchdown and tumbles itself to death.” <br />
*The Space Shuttle Main Engines are notorious for requiring much maintenance between flights, but sadly the over all system is even worse. I would say that if the MTLMOS can not be turned around is less than a week, it should probably not be built. I have faith that handily operable to orbit systems will one day be realized, but that faith does not allow me to answer detailed questions about how they will work. --'''FARTHERRED'''11:10 Central Standard Time 6 November 2008</div>209.23.189.25https://lunarpedia.org/index.php?title=Talk:Luna-Mars_Trade&diff=13962Talk:Luna-Mars Trade2008-11-06T17:10:05Z<p>209.23.189.25: talk</p>
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<div>All of the processes necessary for Luna-Mars trade are not sketched in any great detail, but it seems worth considering. If a mass accelerator can boost the supersonic landing Mars to low Mars orbit vehicle mentioned up to 1025 meters per second, then 49% of the take-off weight gets to orbit.--'''FARTHERRED'''11:28pm Central Standard Time 31 October 2008 <br />
<br />
<br />
Does the original creator realize that by inserting a slash in the article name, he has created a sub-article of [[Luna]]? - [[User:Jarogers2001|Jarogers2001]] 07:09, 1 November 2008 (UTC)<br />
<br />
:Problems like that can be avoided if we disable subpages for mainspace articles. I believe Wikipedia has done this. However, it might be a better idea for Lunarpedia if we keep subpages for mainspace articles. In that case, I suggest moving the content to "Luna-Mars trade". [[User:T.Neo|T.Neo]] 07:41, 1 November 2008 (UTC)<br />
<br />
::Moving it was my thought as well. I rather like subpages. Any objections to a move? - [[User:Jarogers2001|Jarogers2001]] 16:14, 1 November 2008 (UTC)<br />
*Aw shucks. It says right here on my Wiki Reference Card not to use slash, plus sign, number sign, or any of a number of kinds of brackets in a title. I did not have the reference card with me at a distant location but probably would not have consulted it anyway. This is one way to learn. I hope it is not too much trouble to move the article.--[[User:Farred|Farred]] 16:36, 1 November 2008 (UTC)<br />
:It can be moved just like any other article. There is no additional procedure. - [[User:Jarogers2001|Jarogers2001]] 03:53, 2 November 2008 (UTC)<br />
<br />
:::If we disable it, we should also disable it for the seldom used GFDL namespace and the never used CC_Luna namespace, as they have teh same function as the main namespace, just not public domain. -- [[User:Strangelv|Strangelv]] 18:18, 1 November 2008 (UTC)<br />
::::I see no reason to disable it at this time. I intend to use sub-articles in the future. - [[User:Jarogers2001|Jarogers2001]] 03:53, 2 November 2008 (UTC)<br />
*Why should a Mars to low Mars orbit vehicle have wings and land supersonic? The wings should allow the vehicle to kill its orbital velocity through aerodynamic drag when returning to Mars and lift from the wings should allow the vehicle to set down gently on a runway. The orbital speed being considered is only about 40% faster than the SR-71 flew, and the Mars to low Mars orbit vehicle would only move through the atmosphere at that speed for a short time while reentering from orbit. If the SR-71 could tolerate 2450 meters per second for thousands of miles of flight, a Mars to low Mars orbit vehicle should be able to tolerate flying at 3440 meters per second through Mars' upper atmosphere for a few minutes. The vehicle would not move at orbital velocity when touching down on a runway, but it would still need to be supersonic to generate enough lift for a gentle landing.--[[User:Farred|Farred]] 02:47, 4 November 2008 (UTC)<br />
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A lifting reentry for martian cargo is an interesting idea. I have always contemplated capsule type landings. However, I am a bit skeptical about a supersonic landing. If I am correct, supersonic on Mars is faster then on Earth due to thinner air. And, even in the thinner air, any landing gear being deployed would have to resist this force. Add to that what the gear would encounter on contect with the ground, and I don't see a happy landing. To lower the landing speed, one would have to increase the lifting force. Maybe swing wings would work, they will incease compexity.<br />
<br />
How is the shuttle launched from the Martian surface? Is it a vertical or horizontal launch? [[User:T.Neo|T.Neo]] 07:53, 4 November 2008 (UTC)<br />
<br />
*In the case of the speed of sound T.Neo's memory serves falsely. The speed of sound is dependent directly on the temperature and inversely on molecular weight, but it is nearly independent of pressure. The suggested shuttle would take off vertically for the version that puts 36% of take-off weight into orbit. It would be thrown into the atmosphere near the peak of mount Olympus at 1025 meters per second in the version to be boosted by electric acceleration which is suggested to achieve 49% of take-off weight to orbit. SSTO is a less demanding challenge for Mars than for Earth. --[[User:Farred|Farred]] 14:42, 5 November 2008 (UTC)<br />
::Woa. I thought that the speed at which sound propagates is dependent upon the density of the medium, not the temperature. - [[User:Jarogers2001|Jarogers2001]] 19:00, 5 November 2008 (UTC)<br />
<br />
SSTO is definatly much easier on Mars then on Earth.<br />
What is the speed of sound on Mars? What would the landing speed for the shuttle be? WHat kind of forces would the landing gear endure? What would the heat sheild of such a craft be made of? [[User:T.Neo|T.Neo]] 16:07, 5 November 2008 (UTC)<br />
*I will return to the speed of sound on Mars later. For now I was thinking of a titanium steel Aerodynamic shell with heat soak on reentry and an insulated internal compartment for electronics with evaporative cooling using dry ice. Landing gear would be skids with an expendable layer.--[[User:Farred|Farred]] 16:29, 5 November 2008 (UTC)<br />
*The speed of sound on mars at about 0 C is about 240 m/sec making the low orbit velocity about mach 14.2 and and the contemplated electricly accelerated boost about mach 4.2 --[[User:Farred|Farred]] 19:22, 5 November 2008 (UTC)<br />
*I can see how Jarogers2001 might think that the speed of sound is dependent on density since sound travles faster in steel and in water than in air at room temperature. However, we are talking about just the atmosphere of Mars here, so the speed of sound is the square root of the quantity of the specific heat ratio times the gas constant times the temperature devided by the molecular weight quantity closed. That can be rewritten as a function of density, but that would seem an unneeded complication.--[[User:Farred|Farred]] 20:08, 5 November 2008 (UTC)<br />
<br />
Titanium-steel thermal soak confuses me. Thermal soak is when an insulating substance keeps heat away from the airframe. Titanium-steel seems more like a radiative heatshield, where excess heat is radiated away, like the shuttle RCC. However, the problem with the shuttle RCC (And, presumably Titanium-steel) is that they are as good at conducting heat as they are radiating it. This means that the Titanium-steel will conduct heat to the rest of the ship. Not only does the computer need to be cooled, but systems to deploy the landing gear, the RCS, the MEs, etc. Add to that, whatever payload you are carrying might not like being heated up too much. Since the methane (and LOX) tanks take up a lot of space, it might be better to make the upper hull out of thinner material, possibly aluminium.<br />
<br />
Considering where this craft would be working, and the stresses it endures on the way down, it would have to be pretty robust. It needs a minimal use of electronics, and must be maintainable with substances found on Mars. Nothing like the current space shuttle. Think of an aircraft operating out of the Siberian tundra. It must be very robust, like many russian aircraft. [[User:T.Neo|T.Neo]] 20:43, 5 November 2008 (UTC)<br />
*Sorry about “titanium steel.” That shows that I am not very familiar with titanium alloys. Try Grade 6 titanium alloy, containing 5% Aluminum and 2.5% Tin. Perhaps Grade 5 or Grade 9 would be better. I do not feel capable of making a final determination of alloy, but it isn’t going to be simple aluminum. It seems that I have heard of some heat resistant aluminum based alloys, but I can not name a good candidate at the moment. <br />
*As far as cargo heating is concerned, this thing takes cargo up for shipping exports. It comes down empty. That is when the heat threat is a worry. The landing skids are constantly deployed. They are part of the airframe, like ventral fins. The flaps are operated by heat resistant cables. The control motors are in the same insulated box as the electronics. A section of the air frame with the cross section reducing from fore to aft will not have such serious heat threat problems. The reaction control nozzles can stick out there. Any unused reaction control fuel can be dumped once the flaps bite. What are “MEs?” <br />
*I am not familiar with what you mean by heat soak, but the vehicle I describe would just soak up the heat and get hot. The idea is that the exposure to maximum heat threat will be short enough that it will not melt. <br />
*Minimizing the use of electronics would not make the craft more rugged. Electronic components can keep going for decades. Electronics are light enough that spare boards can be shipped with the craft without significant extra expense. Anything that fails can be swapped out. That is Siberia level maintenance. The electronics are necessary for this thing to work. <br />
*Since I am not an aeronautical engineer, I put only limited faith in my own suggestion, but nothing written here so far seems like a serious objection. --[[User:Farred|Farred]] 22:15, 5 November 2008 (UTC)<br />
*I can only roughly guess what speed would be necessary for landing. I guess 1000 miles per hour. That is about mach1.9 on Mars. There is reason for thinking the thermal threat will not be too great. Besides there being only 20% of the energy per pound of reentering spacecraft as there is on Earth, the carbon dioxide atmosphere heats up to a lower temperature for any given amount of heat it absorbs because carbon dioxide is triatomic. Also since carbon dioxide is half again as heavy as the average air molecule, for any given temperature the average carbon dioxide molecule is moving only about 82% as fast as an average air molecule at that temperature. This means that carbon dioxide does not transfer heat as effectively to the skin of a supersonic aircraft as air does. The point of my greatest uncertainty is whether or not the craft can maintain orientational control while supersonic in ground effect. This is an almost completely untested area.<br />
<br />
Pity it only takes cargo on the way up. If I wanted to export anything from the martian system it would probably be mined from Deimos or Phobos. <br />
Landing large cargo on Mars is very tricky. Plans like Mars direct and Mars for less neglect landing. <br />
The Mars Science Laboratory will land with A "skycrane" system. However, this may not hold up well to <br />
sustainability. Is there any way this could be reconfigured for payload delivery to the Martian surface?<br />
Modularity is a good idea. Anything that cannot be made on Mars should be brought from Earth. For example, the MEs (Main Engines, sorry.) will be quite complex. If one breaks, a new one could be delivered from Earth, and just "dropped in". Same with electronics.<br />
<br />
What would the maintainance effort? And what about turnaround time? [[User:T.Neo|T.Neo]] 08:57, 6 November 2008 (UTC)<br />
*The supersonic landing Mars to low Mars orbit shuttle (MTLMOS) concept is just that, a concept. Taking cargo down to Mars would increase the mass of the shuttle and therefore the thermal threat, but I can not produce the numbers that would say that this is possible or that it is not. Just working out the shape of the supersonic airframe, its center of gravity, and control parameters would be quite a task. If someone does that, they might say, “Yeah, we can take a little cargo on the downward leg.” They might say, “We tried but we just can not make it work. It always goes wild on the runway before touchdown and tumbles itself to death.” <br />
*The Space Shuttle Main Engines are notorious for requiring much maintenance between flights, but sadly the over system is even worse. I would say that if the MTLMOS can not be turned around is less than a week, it should probably not be built. I have faith that handily operable to orbit systems will one day be realized, but that faith does not allow me to answer detailed questions about how they will work. --'''FARTHERRED'''11:10 Central Standard Time 6 November 2008</div>209.23.189.25https://lunarpedia.org/index.php?title=Talk:Luna-Mars_Trade&diff=13884Talk:Luna-Mars Trade2008-11-01T04:30:55Z<p>209.23.189.25: Talk:Luna/Mars Trade</p>
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<div>All of the processes necessary for Luna/Mars trade are not sketched in any great detail, but it seems worth considering. If a mass accelerator can boost the supersonic landing Mars to low Mars orbit vehicle mentioned up to 1025 meters per second, then 49% of the take-off weight gets to orbit.--'''FARTHERRED'''11:28pm Central Standard Time</div>209.23.189.25https://lunarpedia.org/index.php?title=Luna-Mars_Trade&diff=13881Luna-Mars Trade2008-11-01T04:10:01Z<p>209.23.189.25: Luna/Mars Trade</p>
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<div>Mars could return dividends at the same time that Luna does if they join forces. Luna has considerable potential for manufacturing and shipping stuff into orbit about Earth where it can be of financial benefit, but Luna is short of Hydrogen, Nitrogen, and Carbon. These elements are not only necessary for life, they are useful for many industrial processes. Mars has all of these elements in reasonably recoverable concentrations, and could export them to Luna and Earth orbiting factories. The cost of lifting them from Mars could become considerably less than the cost of lifting them from Earth. Low Mars orbit, at an altitude of 100 miles has a velocity of 3440 meters per second, less than half of the velocity needed to orbit Earth at that altitude, more than twice the velocity needed to orbit Luna. With a reusable rockets built on Earth to use liquid methane and liquid oxygen, if the exhaust velocity is 3500 meters per second, there should be 36% of the take-off weight in orbit. With wings for a supersonic in ground effect landing in the 0.1 psi Martian atmosphere, the empty weight should be held to 30% leaving 6% of the take-off weight as cargo. If the technology for the supersonic in ground effect landing is not ready soon enough, there is always the possibility that Phobos is stuffed with volatiles. Phobos could be ground up and processed at one end and the tailings dumped at the other end. It should be many years before the entire moon is converted into tailings, during that time Luna and Earth orbiting factories should be churning out a great many solar power satellites, orbital habitats, and orbiting space ports to help lift traffic from Earth. If Phobos is 30% by weight volatiles and ships six thousand tons a year that is part ammonium cyanide and part propane, then after fifty years 100 billionths of Phobos will be processed.<ref> Phobos weighs 1*10^16 kg according to the Phobos article at Wikipedia.</ref> <br />
*reference <br />
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[[category:Business]]</div>209.23.189.25https://lunarpedia.org/index.php?title=Talk:First_Base&diff=13865Talk:First Base2008-10-31T15:50:45Z<p>209.23.189.25: </p>
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<div>The article assumes a six month day/night cycle at the lunar poles. There are several areas around Peary Crater, at the Lunar North Pole, that are known as the Peaks of Eternal Light. They get sunlight 100% of the time in Lunar summer, and 70-90% of the time in Lunar winter. See Peak of Eternal Light article in Wikipedia. The Clementine lunar probe was intended to look for such areas, among other missions.<br />
*The annonymous contributer deserves thanks for directing attention to the Peak of Eternal Light article.--'''FARTHERRED'''10:49am Central Standard Time 31 October 2008</div>209.23.189.25https://lunarpedia.org/index.php?title=First_Base&diff=13864First Base2008-10-31T15:45:40Z<p>209.23.189.25: minor edit</p>
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<div>==Options for First Base==<br />
*A first base on Luna might be located at one of the Peaks of Eternal Light<ref> Peak of Eternal Light article at Wikipedia </ref> at the Lunar North Pole. Access to sunlight for solar power all summer and most of the winter would help maintain operating temperature for the machinery. The landscape might be too rugged to provide a convenient rocket landing area and base site the right distance apart. <br />
*Another possibility is to put a base in the best flat place with a covenient area for rocket landings, and provide [[Nuclear Power]]. There have been some political difficulties with nuclear power in space in the past. <br />
*It might be most economical to make a first base away from the polar region of Luna, a base for remotely controlled devices. The six month nights at the poles require some power source, such as people might get by establishing a power distribution grid of solar power stations ringing the pole at a distance of about fifty miles. Such power stations ought to have solar cells facing away from the pole on convenient hills. The trouble is that people would have difficulty establishing the grid during the five months that we can count on solar power at a lunar pole. A power station atop a 2000 foot tower could provide power through the lunar polar winter, but that would be no cinch either. <br />
*The “[[Long Endurance Rovers]]” article Thermal Management section gives a scheme for rejecting heat from a radiator on Luna away from the poles. The radiator is protected from sunlight and from infrared radiation of the landscape. Basically the radiator is set in a wall in an east west running ditch of parabolic cross section lined with shiny aluminum foil. The axis of the parabola coincides with the wall and is tilted away from the vertical toward the equator by an angle equal to the latitude. The top of the wall is below the focal point of the parabola so that all of the sunlight falling in the ditch is reflected back into space. This sort of radiator could be used to reject the heat of a hydrogen and oxygen liquification plant. So these gasses could be conveniently stored for use in fuel cells during the two week and eighteen hour night. Cryogenic tank insulation is not much of a problem on Luna where vacuum is all around. Just pack the liquid hydrogen tank in a couple of feet of fines sifted from the regolith and that should suffice. Water from the fuel cells would build up during the night and need to be stored in a tank where it will not freeze. Solar cells would power electrolysis during the day to recover the hydrogen and oxygen, and power the liquifaction process. There is considerable loss of power in storing it for reuse this way, but it is all stuff people know how to do. <br />
*Add up the requirements. The tankage, the liquifaction plant, the protected radiator, the fuel cells, the supply of liquid hydrogen and oxygen, the thermally insulated building, the electrolysis unit. For a small base that could actually be shipped to Luna it is still less costly than the polar power tower or an entire power distribution grid. Start small and build up to the power distribution grid over a period of a few years. Meanwhile rovers could have some place to stay at night where they won’t freeze to death. There would be no major activities at night, just enough power to stay alive. Naturally the elaborate pressure vessels with air locks and plumbing necessary for people ought to wait until there is more time to provide such out of mainly lunar materials. <br />
*One possibility for the shelter which would be a major feature of a first base would be based on structural members that are cloth tubes stuffed with regolith. The tubes could have their seams laced up as they are filled with regolith, then more regolith piled on top. Only the cloth needs to be sent from Earth. More substantial buildings (as described in [[Sintered Brick Construction]]) could be built from local materials when there is time to develop some industry. Remote controlled rovers and manipulators could set out from a base over a few years and establish a circum polar power distribution grid within a possible time frame. From that point the requirements for [[Bootstrapping Industry]] should be clear. <br />
*Reference <br />
<references/><br />
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[[category:Infrastructures]]</div>209.23.189.25https://lunarpedia.org/index.php?title=Category_talk:Alkaline_Earth_Metals&diff=13591Category talk:Alkaline Earth Metals2008-10-17T13:48:11Z<p>209.23.189.25: picky picky</p>
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<div>There has been some inconsistency in the capitalization of title words, for example "Alkaline earth metals" has just the first word capitalized and "Advanced Automation for Space Missions" has all words but prepositions capitalized. Lunarpedia might have a definite policy for this, or might wish to make one. --'''FARTHERRED'''8:45am Central Standard Time 17 October 2008</div>209.23.189.25https://lunarpedia.org/index.php?title=Covered_Roads&diff=13432Covered Roads2008-10-11T15:01:40Z<p>209.23.189.25: Covered Roads</p>
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<div>*On Luna people will want smooth roads that are dust free and do not buckle or crack with the monthly temperature changes. Pavement can be had by melting the soil. To reduce overall brittleness, bricks of pavement could be held together by [[Lunar Cement]]. To reduce the temperature extremes that this pavement is subjected to, the road could be covered with corrugated sheets of glass, much a very long quonset hut. If instead of the corrugations running exactly in the circumferential direction, they take a helical path over the semi cylindrical covering of the road, then alternate sheets of right hand and left hand spiraling corrugations could be laid over one another and automatically assume the correct layer spacing. Perhaps just two layers of corrugated glass sheet and a covering of fines from the lunar soil would provide adequate protection from micrometeoroids, dust, ultraviolet and other radiations that charge up dust particles, and thermal variations. Three electrical transmission rails could run down the length of the road to power vehicles. South bound vehicles on the west side of the road would use the west side of the center rail. In the vacuum large hub wheels with the thin rim and tire magnetically suspended from the hub would require no grease and would allow speeds over 300 kilometers per hour. It would be much like a magnetically levitated train with the rail picked up behind the wheel hub and laid down in front of it. Perhaps elevated [[Railroads]] would be a better option. It would depend upon the cost of iron rails on a supporting framework compared to the cost of glass block paving and glass roofing.<br />
[[category:Ground Transport]]</div>209.23.189.25https://lunarpedia.org/index.php?title=Luna_and_Mars_Characteristics&diff=13426Luna and Mars Characteristics2008-10-10T10:43:13Z<p>209.23.189.25: minor edit</p>
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<div>{| border=1<br />
|+ ''' Luna's and Mars' Characteristics ''' <br />
! Quality !! Luna !! Mars <br />
|-<br />
| ''Atmosphere'' || vacuum || 0.1 psi Carbondioxide <br />
|-<br />
| Advantages || no barrier to high speed travel __ allows use of structural materials incompatible with oxygen and water __ no barier to observations __ no wind born dust __ no requirement for structures to withstand weather || convenient source of carbon & oxygen __ allows use of aerobraking and other aerodynamic effects __ protects against electrostaticly levitated dust and most meteors <br />
|-<br />
| Disadvantages || leads to dewetting of lubricated surfaces __ can not be breathed by people or internal combustion engines __ requires space suit protection of people __ requires pressure chambers for industrial processing involving most liquids __ requires pressure chambers for industrial collection of gas __ no protection against micrometeoroids or electrostaticly levitated dust || can not be breathed by people or internal combustion engines __ requires about the same suit protection of people as a vacuum __ requires pressure chambers for industrial processing involving most liquids __ blows dust storms __ interferes with observations __ requires structural considerations to deal with weather __ does not permit electrical acceleration to orbital velocity<br />
|-<br />
| ''Gravity'' || 1.62 meters per second squared || 3.66 meters per second squared <br />
|-<br />
| Advantages || lower loading on structures to resist gravity than on Mars __ 04.7% of energy needed to orbit Earth can get to lunar orbit || lower loading on structures to resist gravity than on Earth __ 20% of energy needed to orbit Earth can get to Mars orbit <br />
|-<br />
| Disadvantages || lunar gravity may be insufficient to maintain human health __ low gravity causes problems with low traction for construction work || Mars gravity may be insufficient to maintain human health __ low gravity causes problems with low traction for construction work <br />
|-<br />
| Round Trip Communications Delay || 2.56 seconds || about 23 minutes average, about 540 times the delay for Luna<br />
|}<br />
<br />
<br />
[[category:Comparison of Luna and Mars]]</div>209.23.189.25https://lunarpedia.org/index.php?title=Lunar_Cement&diff=13396Lunar Cement2008-09-28T10:38:24Z<p>209.23.189.25: showing reference</p>
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<div>= Lunar Cement =<br />
*The lack of the availability of concrete ready mix on Luna has been cited as a problem for lunar colonies. Indeed, the scarcity of water on Luna leads us to predict that this old standby of structural engineering will be left behind on Earth. What can replace it? <br />
*What is needed is a cement that is liquid at reasonable temperatures for construction and cures at reasonable temperatures, filler material in fine grain size for mortar and filler in grades of coarser chunks for concrete. All materials must be reasonably available on Luna. <br />
*One possibility for cement is an analog to the dental filling amalgams used on Earth. Amalgams are alloys of Mercury which are mixed from liquid mercury and a powder containing the balance of the ingredients, such as silver or gold. Minor amounts of other elements have been shown by experience to produce good results. Amalgams can be mixed and cure in a few minutes at room temperature. The mixed alloy is pressed into a cavity and fills it. The filling is typically shaped by carving as it hardens within minutes. <br />
*Sodium, potassium and aluminum are more plentiful on Luna than mercury, gold and silver. So one should try forming an alloy from sodium potassium eutectic (NaK) <ref> http://www.creativeengineers.com/chemical-processing-glossary.html </ref> which is liquid down to -12 degrees C and powdered aluminum. Minor additions to the alloy could be added to the liquid aluminum before forming a powder. Magnesium, calcium, silicon, and boron might be considered. Mixing such an alloy could be done at near standard temperature and vacuum on Luna. Experiments on Earth could be dune in a glove box with an argon atmosphere. <br />
*Sodium and potassium can sublime away in a vacuum and the eutectic evaporates so these things would be stored in sealed containers on Luna and the eutectic would be exposed to vacuum only for a limited time. Vapor deposition occurs on Luna whenever there is a substantial equilibrium vapor pressure of exposed materials. So vapor deposition must be taken into account. A sodium, potassium, aluminum cement could be used in a mortar to hold bricks together on Luna wherever the structure will not house an oxygen atmosphere. Where people and thus an oxygen atmosphere will be contained something like a silicone polymer is called for. Carbon needed to produce silicone polymers will likely need to be imported. <br />
*Reference <br />
<references/> <br />
<br />
[[category:Infrastructures]]</div>209.23.189.25https://lunarpedia.org/index.php?title=Lunar_Cement&diff=13395Lunar Cement2008-09-28T10:30:37Z<p>209.23.189.25: New page: = Lunar Cement = *The lack of the availability of concrete ready mix on Luna has been cited as a problem for lunar colonies. Indeed, the scarcity of water on Luna leads us to predict that...</p>
<hr />
<div>= Lunar Cement =<br />
*The lack of the availability of concrete ready mix on Luna has been cited as a problem for lunar colonies. Indeed, the scarcity of water on Luna leads us to predict that this old standby of structural engineering will be left behind on Earth. What can replace it? <br />
*What is needed is a cement that is liquid at reasonable temperatures for construction and cures at reasonable temperatures, filler material in fine grain size for mortar and filler in grades of coarser chunks for concrete. All materials must be reasonably available on Luna. <br />
*One possibility for cement is an analog to the dental filling amalgams used on Earth. Amalgams are alloys of Mercury which are mixed from liquid mercury and a powder containing the balance of the ingredients, such as silver or gold. Minor amounts of other elements have been shown by experience to produce good results. Amalgams can be mixed and cure in a few minutes at room temperature. The mixed alloy is pressed into a cavity and fills it. The filling is typically shaped by carving as it hardens within minutes. <br />
*Sodium, potassium and aluminum are more plentiful on Luna than mercury, gold and silver. So one should try forming an alloy from sodium potassium eutectic (NaK) <ref> http://www.creativeengineers.com/chemical-processing-glossary.html </ref> which is liquid down to -12 degrees C and powdered aluminum. Minor additions to the alloy could be added to the liquid aluminum before forming a powder. Magnesium, calcium, silicon, and boron might be considered. Mixing such an alloy could be done at near standard temperature and vacuum on Luna. Experiments on Earth could be dune in a glove box with an argon atmosphere. <br />
*Sodium and potassium can sublime away in a vacuum and the eutectic evaporates so these things would be stored in sealed containers on Luna and the eutectic would be exposed to vacuum only for a limited time. Vapor deposition occurs on Luna whenever there is a substantial equilibrium vapor pressure of exposed materials. So vapor deposition must be taken into account. A sodium, potassium, aluminum cement could be used in a mortar to hold bricks together on Luna wherever the structure will not house an oxygen atmosphere. Where people and thus an oxygen atmosphere will be contained something like a silicone polymer is called for. Carbon needed to produce silicone polymers will likely need to be imported. <br />
<br />
[[category:Infrastructures]]</div>209.23.189.25https://lunarpedia.org/index.php?title=Talk:Robots_in_Space_Suits&diff=13393Talk:Robots in Space Suits2008-09-19T13:19:43Z<p>209.23.189.25: </p>
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<div>Is this space suits as in human space suits? Robots will not look very human. Try stuffing a Mars Rover into a space suit. Otherwise, The idea of having gaskets around joints is a sound one. [[User:T.Neo|T.Neo]] 07:35, 15 September 2008 (UTC)<br />
Thanks to T.Neo for pointing out a lack of clarity. --'''FARTHERRED''' 8:19 am Central Standard Time 19 September 2008</div>209.23.189.25https://lunarpedia.org/index.php?title=Robots_in_Space_Suits&diff=13392Robots in Space Suits2008-09-19T13:15:29Z<p>209.23.189.25: </p>
<hr />
<div>*The lack of long endurance lubricants in vacuum could be worked around by robots wearing space suits. While usually the spacesuit is made to fit the person, with robots the possibility arises that robots could be made to fit spacesuits. So let it be plain, what is meant is not a man shaped robot wearing a man’s suit, but a robots in spacesuits with six or more legs each and as many arms as required. Perhaps 0.3 psi pressure in the suits would do for robots. At least a gas tight covering of knee or elbow joints could be done with a bellows that has flanges pressed to points above and below the joint by threaded rings. Electrical power wire, control wire, and thermal management fluid hoses could run in a bundle outside of the bellows and have connectors for wires and hoses that would run around the bellows to the pressurized space around the joint . That way the wires and hoses could be disconnected, the bellows unfastened, and the joint unpinned for maintenance. When the joint is unpinned the bellows could be removed and replaced if necessary. <br />
*The astute reader will realize that this sort of joint covering will not work with rotary bearings of wheels rolling over the ground. So robots could walk and wheeled vehicles could have magnetic bearings. Such vehicles would not be suitable for bouncing over rough terrain, but might give high speed performance over smooth [[Roads]]. Wheeled vehicles might work with ordinary greased bearings and frequent lube jobs, or the lubricant rquirement might be solved by special grease and thermal management. The rotary bearing would be within the body of the robot ( as described in the Dust section of [[Long Endurance Rovers]] ) where thermal management could be effective. <br />
*A completely enclosed set of bearings and directional antenna could constantly communicate with a ground station from a rotating space station. A few layers of stuff transparent to the frequency used sandwhiched with three inch layers of vacuum could protect the gas retaining envelope from micrometeoroids. This sort of raydome would need to be assembled in orbit since it would be to large to fit in a payload faring. <br />
*An arm with multiple gas enveloped joints along its length could point a telescope in arbitrary directions. Panning through a 360 degree sweep would cause the image to roll 360 degrees unless there were a rotary bearing for roll control at the telescope end of the arm. A gas tight envelope for a roll control bearing could be maintained if part of the envelope were optical quality glass through which the telescope could see its target. If an ordinary short life rotary bearing is used, loss of roll control would be tollerated when the bearing failed. <br />
<br />
[[category:Robots]]</div>209.23.189.25https://lunarpedia.org/index.php?title=Talk:Railroads&diff=13385Talk:Railroads2008-09-17T17:02:10Z<p>209.23.189.25: /* Railroads on MArs and asteroids */</p>
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<div>Just thought you might be interested<br><br />
http://www.erosproject.com/metrocircus.html?source=ErosProject<br><br />
--[[User:mdelaney|MikeD]] - 20:49, 10 March 2007 (GMT)<br />
<br />
===cost due to gravity=== <br />
<br />
This statement is questionable: "The cost of building such a structure compared to earth is greatly reduced due to the 1/6 [[Gravity]]" <br />
Building infrastructure on the Moon will be extremely expensive compared to Earth. 1/6 gravity helps a little, but does not make it cheaper than Earth. Please reword this sentence. thanks.[[User:Cfrjlr|Charles F. Radley]] 14:14, 10 March 2007 (PST)<br />
<br />
===Restructure of Bulk/cargo/passenger and addition of new section===<br />
I've tried to restructure the proposed progression from bulk to passenger and add a section on types, but I still find the organizational structure of this article to be unsatisfactory. -- [[User:Strangelv|Strangelv]] 08:16, 21 September 2007 (UTC)<br />
<br />
<br />
== Railroads on MArs and asteroids ==<br />
<br />
"Mars <br />
With such a thin atmosphere and no oxygen, Mars has essentially the same dynamics as the moon only with more gravity (better cornering)."<br />
<br />
Don't compare Mars to the Moon. Mars has windblown dust, etc. "More gravity" means more materials to construct the railroad. <br />
<br />
<br />
"Asteroids <br />
All asteroid like objects have a gravitational force insufficient for traditional railways. The modifications necessary are two fold. An upper track must be added like roller coaster to be able to go a reasonable speed without jumping the track. All materials must be securely fastened with either lids or binding clamps."<br />
<br />
A railroad is definatly not neccesary on an asteroid. Maybe a tether an pully system between two spacecraft hovering above the surface. I would not really bother attaching something to any asteroid, especially a rubble pile, since it would just float away. [[User:T.Neo|T.Neo]] 07:27, 15 September 2008 (UTC)<br />
<br />
*It is certainly possible that things could be rigidly attached to an asteroid, even it does happen to be a rubble pile. Ceres for example has an escape velocity of 1140 <ref> http://en.wikipedia.org article on “Ceres (dwarf planet)” </ref> miles per hour. So things do not just drift away. With a gravity of only 1/36th of a g, things that are dislodged might fly a ways before coming back to ground, but it would be hard to get them into orbit. If it were desired to move something from one point on Ceres equator to the opposite point, it would have to be moved 1500 kilometers. So it is conceivable that a railroad could someday be useful.<br />
*reference<br />
<references/><br />
--'''FARTHERRED''' 11:57AM Central Standard Time 17 September 20008</div>209.23.189.25https://lunarpedia.org/index.php?title=Talk:Railroads&diff=13384Talk:Railroads2008-09-17T16:59:37Z<p>209.23.189.25: </p>
<hr />
<div>Just thought you might be interested<br><br />
http://www.erosproject.com/metrocircus.html?source=ErosProject<br><br />
--[[User:mdelaney|MikeD]] - 20:49, 10 March 2007 (GMT)<br />
<br />
===cost due to gravity=== <br />
<br />
This statement is questionable: "The cost of building such a structure compared to earth is greatly reduced due to the 1/6 [[Gravity]]" <br />
Building infrastructure on the Moon will be extremely expensive compared to Earth. 1/6 gravity helps a little, but does not make it cheaper than Earth. Please reword this sentence. thanks.[[User:Cfrjlr|Charles F. Radley]] 14:14, 10 March 2007 (PST)<br />
<br />
===Restructure of Bulk/cargo/passenger and addition of new section===<br />
I've tried to restructure the proposed progression from bulk to passenger and add a section on types, but I still find the organizational structure of this article to be unsatisfactory. -- [[User:Strangelv|Strangelv]] 08:16, 21 September 2007 (UTC)<br />
<br />
<br />
== Railroads on MArs and asteroids ==<br />
<br />
"Mars <br />
With such a thin atmosphere and no oxygen, Mars has essentially the same dynamics as the moon only with more gravity (better cornering)."<br />
<br />
Don't compare Mars to the Moon. Mars has windblown dust, etc. "More gravity" means more materials to construct the railroad. <br />
<br />
<br />
"Asteroids <br />
All asteroid like objects have a gravitational force insufficient for traditional railways. The modifications necessary are two fold. An upper track must be added like roller coaster to be able to go a reasonable speed without jumping the track. All materials must be securely fastened with either lids or binding clamps."<br />
<br />
A railroad is definatly not neccesary on an asteroid. Maybe a tether an pully system between two spacecraft hovering above the surface. I would not really bother attaching something to any asteroid, especially a rubble pile, since it would just float away. [[User:T.Neo|T.Neo]] 07:27, 15 September 2008 (UTC)<br />
<br />
*It is certainly possible that things could be rigidly attached to an asteroid, even it does happen to be a rubble pile. Ceres for example has an escape velocity of 1140 <ref> http://en.wikipedia.org article on “Ceres (dwarf planet)” </ref> miles per hour. So things do not just drift away. With a gravity of only 1/36th of a g, things that are dislodged might fly a ways before coming back to ground, but it would be hard to get them into orbit. If it were desired to move something from one point on Ceres equator to the opposite point, it would have to be moved 1500 kilometers. So it is conceivable that a railroad could someday be useful.<br />
*reference<br />
<refrences/><br />
--'''FARTHERRED''' 11:57AM Central Standard Time 17 September 20008</div>209.23.189.25https://lunarpedia.org/index.php?title=Robots_in_Space_Suits&diff=13383Robots in Space Suits2008-09-17T15:06:11Z<p>209.23.189.25: </p>
<hr />
<div>*The lack of long endurance lubricants in vacuum could be worked around by robots wearing space suits. Perhaps 0.3 psi would do for robots. At least a gas tight covering of knee of elbow joints could be done with a bellows that has a flanges pressed to points above and below the joint by a threaded ring. Electrical power wire, control wire, and thermal management fluid hoses could run in a bundle outside of the bellows and have connectors for wires and hoses that would run around the bellows to the pressurized space around the joint . That way the wires and hoses could be disconnected, the bellows unfastened, and the joint unpinned for maintenance. <br />
*The astute reader will realize that this sort of joint covering will not work with rotary bearings of wheels rolling over the ground. So robots could walk and wheeled vehicles could have magnetic bearings. Such vehicles would not be suitable for bouncing over rough terrain, but might give high speed performance over smooth [[Roads]]. Wheeled vehicles might work with ordinary greased bearings and frequent lube jobs, or the lubricant rquirement might be solved by special grease and thermal management. The rotary bearing would be within the body of the robot ( as described in the Dust section of [[Long Endurance Rovers]] ) where thermal management could be effective. <br />
*A completely enclosed set of bearings and directional antenna could constantly communicate with a ground station from a rotating space station. A few layers of stuff transparent to the frequency used sandwhiched with three inch layers of vacuum could protect the gas retaining envelope from micrometeoroids. This sort of raydome would need to be assembled in orbit since it would be to large to fit in a payload faring. <br />
*An arm with multiple gas enveloped joints along its length could point a telescope in arbitrary directions. Panning through a 360 degree sweep would cause the image to roll 360 degrees unless there were a rotary bearing for roll control at the telescope end of the arm. A gas tight envelope for a roll control bearing could be maintained if part of the envelope were optical quality glass through which the telescope could see its target. If an ordinary short life rotary bearing is used, loss of roll control would be tollerated when the bearing failed. <br />
<br />
[[category:Robots]]</div>209.23.189.25https://lunarpedia.org/index.php?title=Mass_Drivers&diff=13339Mass Drivers2008-09-03T16:15:06Z<p>209.23.189.25: /* The First Lunar Mass Driver */</p>
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There have been many suggestions for mass drivers on Luna for the exportation of raw materials and other purposes, notably by Gerard K. O'Neill (God rest his soul) and the Space Studies Institute. Plans can keep the power requirement low by calling for a low payload size. Higher acceleration rates allow shorter track. High firing rates keep the investment actively earning its return.<br />
<br />
<br />
<br />
<br />
== Circum Polar Mass Driver == <br />
<br />
Consider here a circular mass driver or mass accelerator which would keep power requirements low by spreading the acceleration out over many laps of a circular track. The payload could be about 200 kilograms. If there are passengers or cargo available every 110 minutes for rendezvous with a catcher satelite, it can keep constantly busy. Suitability for passenger service requires a low radial acceleration, 30 meters per second squared (about 3 g's) will do. This in turn requires a large diameter (about 120 miles). The shape of the device is like a very regular volcanic mountain peak with gently sloping sides and a circular crater on top. The accelerator track would run along the vertical wall of the circular crater. When the payload and carrier reach orbital velocity (1680 meters per second), the payload is dropped tangentially outward over the top of the wall. A counter weight may be required on the carrier near the base of the wall to ballance the carrier. Since the diameter of the track is 120 miles, there is about one and two thirds miles bulge of the curvature of Luna interfering with line of sight communication from one side of the track to the other. The plane of the circular track makes a 3.2 degree angle with the surface of Luna. (It's like a slice off of the top of Luna one and two thirds miles thick at the Pole.) Payloads launched tangentialy from the track, however, deviate from that plane by curving downward toward Luna in an orbital path. This makes it more likely than otherwise that a payload would smash into a mountain peak. So the accelerator track should be built up on fill as high as practical and care should be taken in choosing the exact dirrection of launch. The circular accelerator should be centered at the North pole while the catcher satelite would orbit about once per 110 minutes at an inclination of about 86.8 degrees. So it would pass over one or another spot on the circular track with every orbit as Luna rotates under the orbit. It could catch a payload whenever a mountain peak did not interfere. Troublesome peaks could be razed. <br />
<br />
The above specifications would require 43 kilowatts average power put constantly into payloads plus power to accelerate the carrier and allow for the losses in magnetic levitation. Unfortunately, the carrier can not constantly accelerate because it must come to a stop to be ready to pick up the next payload. Two tracks, the second with 10 meters less radius and 2 meters more altitude than the first would allow one track to accelerate while the other uses regenerative braking. <br />
<br />
As long as we consider developments that must be many years in the future, there is a capability of adding carriers in a train as there is increased available power and need for cargo tonnage. The whole 370 mile circumference of the accelerator could be filled with one train of carriers. The payloads could be connected by rope and the whole train of payloads launched from one point on the cicumference into one orbit as 5 minutes and 53 seconds go by. <br />
<br />
----<br />
<br />
==The First Lunar Mass Driver==<br />
<br />
Catching one kilogram loads of sintered soils at L2 (a [[Lagrangian point]] ) one a second or one every few seconds by having them smash into a grid and having the bits go through to fill up a cone is unacceptable. A continuing rain of dust and grit would be produced at L2 from whence it would fill up the plane of the Earth Luna system and trail a cloud into independent orbit around the sun. <ref> http://en.wikipedia.org/wiki/Lagrange_points </ref> The dust from thousands of tons of stuff splashed into a catcher would sandblast every satelite in orbit. <br />
===What Will Work===<br />
Instead a mass driver should launch 10 kilogram loads as fast as can be managed. This should be once a minute or better. The payloads should go into equatorial orbit about Luna. Each payload should be about a 10.1 kilogram spaceship containing a supposed 100 gram liquid oxygen flash baulb rocket(It has a combustion chamber stuffed with aluminum coated aluminum oxide threads. An electric pulse ignites the thermite that melts the seal on the spring loaded valve to the oxygen tank open). <ref> The performance characteristics of this hypothetical rocket are themselves hypothetical. See discussion for this article. </ref> The payload is spin stabilized and the rocket is fired by a timer at apolune to circularize the orbit. The payloads orbit at a 111 minute orbit at 30 kilometers altitude. The catcher satelite orbits at 127 kilometers altitude once every 120 minutes. A net is depended by tether from the catcher and sweeps up the entire payload orbit once in twenty-four hours.<br />
<br />
===Worth Waiting===<br />
Previous schemes called for a mass driver built as prefabricated sections on Earth for shipping raw materials into orbit for processing. This scheme calls for the mass driver to be built from lunar materials by remote controled devices. So there will be the infrastructure for manufacturing many things by the time the mass driver comes on line. The same things that went into building the mass driver will be shipped out as export. We will let a full engineering team calculate which scheme requires more stuff shipped from earth by the time of first exports.<br />
===References===<br />
<references/></div>209.23.189.25https://lunarpedia.org/index.php?title=Size_of_Infrastructure&diff=13335Size of Infrastructure2008-08-30T14:38:27Z<p>209.23.189.25: </p>
<hr />
<div>{{cleanup}}<br />
<br />
== From "The Machine Stops" to Nano-assemblers == <br />
:There are two fictional visions of reproducing industrial infrastructure that are near opposite ends in scale. In a story "The Machine Stops" E.M. Forster in 1909 depicted all people on Earth and all of their machines interconnected as one self sustaining growing unit. Eric Drexler and others suggested that a desk top scale nano-assembler (once one was perfected) could make other nano-assemblers <ref> Chemical & Engineering News, 1 December 2003. vol 81 #48. CENEAR 81 48 pp.37-42. http://pubs.acs.org/cen/coverstory/8148/8148counterpoint.html </ref> from the appropriate raw materials and power; and thus be a full reproducing industrial infrastructure to fit in a moving van. God has already got one up on Drexler with the carrot seed. <br />
:Opponents of putting industrial infrastructure on Luna tend to Forster's vision. They seem to think that if an industrial infrastructure is not as big as the Earth including as many people as live today, it can not sustain itself and produce product, and since it is impossible to ship such to Luna, people should not try. <br />
:Some proponents of industrial infrastructure on Luna seem to think that fully self maintaining and self reproducing industrial equipment could be sent to Luna with (perhaps) a half dozen Ares V launches, with these launches including (perhaps a half dozen) astronauts who will be living in locally built housing and running the show the same week that three of them arrive on the first Ares V trip. They could be imagining an industrial base something like Drexler's table top nano-factories to support all the needs of astronauts from the start, or they could imagine that congress will cheerfully keep sending tang and freeze dried filet mignon to Luna for years. Actually the way to kill a government funded space program is to insist that the program simply must have resources that are more expensive than congress is willing to provide. The job of any engineer is to solve a problem while working within certain constraints. The tighter the contraints in which something can be accomplished, the more cost effective and/or profitable that accomplishment will be.<br />
:Actually neither Drexler's nano-factories nor Ares V launchers are necessary to build a lunar base that can support people. Time and remote controlled equipment that neither eats nor drinks nor breaths can establish the infrastructure that can support people and allow the export of products that will pay for imports. That is perhaps fifty years before there are profitable exports, not quite so long before the considerable benefits of hands on work can aid the lunar enterprise. <br />
:All necessary remotely operated devices can be sent to Luna on moderate size rockets. The Delta IV heavy can put 19000 pounds into low Earth orbit. A modest modification to make the rocket more appropriate for the low Earth orbit mission than the Geostationary orbit mission could improve on that. A useful unmanned space station that would provide a platform for vehicle assembly and refueling would allow 19000 pound payloads to be assembled with a fully fueled vehicle that would put 19000 pounds on Luna. <br />
:A useful unmanned space station would have a constantly rotating portion housing motors and solar cells communications and if necessary some structure and ballast that would increase the moment of inertia for the constantly spinning portion. There would be a spin up spin down portion to rotate on the same axis. It would have solar cells communications and a refueling and assembly platform. Cargoes of fuel and rockets to be refueled or assembled would dock with the spin up spin down portion while it is not rotating. This is a capability that was demonstrated early in the space program. The center of mass of the loaded platform would be adjusted to the common spin axis of the station. The platform would be spun up to a mere 20 centimeters per second squared radial acceleration and fuel would be transferred with no problem. <br />
:The two sections of the refueling station would be connected by magnetic bearings and an electric motor. There would no solid surface contact between the two and no need for lubricants. <br />
:Savings comes from not building Ares V nor maintaining launching facilities for Ares V or any other expensive heavy lift vehicle. More savings comes from a higher frequency of launch of medium lift rockets resulting (at least potentially) in lower unit cost. NASA does not do things this way because of an institutional bias toward using big rockets. There is some argument for using big rockets in all at once launches for manned Mars missions, but the expense should all be counted toward the manned Mars missions. A program of [[Bootstrapping Industry]] on Luna does not require big rockets. <br />
:This does not need to result in a smaller NASA. Spending the same money on cheaper per each missions results in more missions. <br />
===References===<br />
<references/><br />
[[category:Infrastructures]]</div>209.23.189.25https://lunarpedia.org/index.php?title=Size_of_Infrastructure&diff=13334Size of Infrastructure2008-08-30T14:36:38Z<p>209.23.189.25: </p>
<hr />
<div>{{cleanup}}<br />
<br />
== From "The Machine Stops" to Nano-assemblers == <br />
:There are two fictional visions of reproducing industrial infrastructure that are near opposite ends in scale. In a story "The Machine Stops" E.M. Forster in 1909 depicted all people on Earth and all of their machines interconnected as one self sustaining growing unit. Eric Drexler and others suggested that a desk top scale nano-assembler (once one was perfected) could make other nano-assemblers <ref> Chemical & Engineering News, 1 December 2003. vol 81 #48. CENEAR 81 48 pp.37-42. http://pubs.acs.org/cen/coverstory/8148/8148counterpoint.html </ref> from the appropriate raw materials and power; and thus be a full reproducing industrial infrastructure to fit in a moving van. God has already got one up on Drexler with the carrot seed. <br />
:Opponents of putting industrial infrastructure on Luna tend to Forster's vision. They seem to think that if an industrial infrastructure is not as big as the Earth including as many people as live today, it can not sustain itself and produce product, and since it is impossible to ship such to Luna, people should not try. <br />
:Some proponents of industrial infrastructure on Luna seem to think that fully self maintaining and self reproducing industrial equipment could be sent to Luna with (perhaps) a half dozen Ares V launches, with these launches including (perhaps a half dozen) astronauts who will be living in locally built housing and running the show the same week that three of them arrive on the first Ares V trip. They could be imagining an industrial base something like Drexler's table top nano-factories to support all the needs of astronauts from the start, or they could imagine that congress will cheerfully keep sending tang and freeze dried filet mignon to Luna for years. Actually the way to kill a government funded space program is to insist that the program simply must have resources that are more expensive than congress is willing to provide. The job of any engineer is to solve a problem while working within certain constraints. The tighter the contraints in which something can be accomplished, the more cost effective and/or profitable that accomplishment will be.<br />
:Actually neither Drexler's nano-factories nor Ares V launchers are necessary to build a lunar base that can support people. Time and remote controlled equipment that neither eats nor drinks nor breaths can establish the infrastructure that can support people and allow the export of products that will pay for imports. That is perhaps fifty years before there are profitable exports, not quite so long before the considerable benefits of hands on work can aid the lunar enterprise. <br />
:All necessary remotely operated devices can be sent to Luna on moderate size rockets. The Delta IV can put 19000 pounds into low Earth orbit. A modest modification to make the rocket more appropriate for the low Earth orbit mission than the Geostationary orbit mission could improve on that. A useful unmanned space station that would provide a platform for vehicle assembly and refueling would allow 19000 pound payloads to be assembled with a fully fueled vehicle that would put 19000 pounds on Luna. <br />
:A useful unmanned space station would have a constantly rotating portion housing motors and solar cells communications and if necessary some structure and ballast that would increase the moment of inertia for the constantly spinning portion. There would be a spin up spin down portion to rotate on the same axis. It would have solar cells communications and a refueling and assembly platform. Cargoes of fuel and rockets to be refueled or assembled would dock with the spin up spin down portion while it is not rotating. This is a capability that was demonstrated early in the space program. The center of mass of the loaded platform would be adjusted to the common spin axis of the station. The platform would be spun up to a mere 20 centimeters per second squared radial acceleration and fuel would be transferred with no problem. <br />
:The two sections of the refueling station would be connected by magnetic bearings and an electric motor. There would no solid surface contact between the two and no need for lubricants. <br />
:Savings comes from not building Ares V nor maintaining launching facilities for Ares V or any other expensive heavy lift vehicle. More savings comes from a higher frequency of launch of medium lift rockets resulting (at least potentially) in lower unit cost. NASA does not do things this way because of an institutional bias toward using big rockets. There is some argument for using big rockets in all at once launches for manned Mars missions, but the expense should all be counted toward the manned Mars missions. A program of [[Bootstrapping Industry]] on Luna does not require big rockets. <br />
:This does not need to result in a smaller NASA. Spending the same money on cheaper per each missions results in more missions. <br />
===References===<br />
<references/><br />
[[category:Infrastructures]]</div>209.23.189.25https://lunarpedia.org/index.php?title=Size_of_Infrastructure&diff=13330Size of Infrastructure2008-08-28T21:56:08Z<p>209.23.189.25: /* From "The Machine Stops" to Nano-assemblers */</p>
<hr />
<div>== From "The Machine Stops" to Nano-assemblers == <br />
:There are two fictional visions of reproducing industrial infrastructure that are near opposite ends in scale. In a story "The Machine Stops" E.M. Forster in 1909 depicted all people on Earth and all of their machines interconnected as one self sustaining growing unit. Eric Drexler and others suggested that a desk top scale nano-assembler (once one was perfected) could make other nano-assemblers <ref> Chemical & Engineering News, 1 December 2003. vol 81 #48. CENEAR 81 48 pp.37-42. http://pubs.acs.org/cen/coverstory/8148/8148counterpoint.html </ref> from the appropriate raw materials and power; and thus be a full reproducing industrial infrastructure to fit in a moving van. God has already got one up on Drexler with the carrot seed. <br />
Opponents of putting industrial infrastructure on Luna tend to Forster's vision. They seem to think that if an industrial infrastructure is not as big as the Earth including as many people as live today, it can not sustain itself and produce product, and since it is impossible to ship such to Luna, people should not try. <br />
Some proponents of industrial infrastructure on Luna seem to think that fully self maintaining and self reproducing industrial equipment could be sent to Luna with (perhaps) a half dozen Ares V launches, with these launches including (perhaps a half dozen) astronauts who will be living in locally built housing and running the show the same week that three of them arrive on the first Ares V trip. They could be imagining an industrial base something like Drexler's table top nano-factories to support all the needs of astronauts from the start, or they could imagine that congress will cheerfully keep sending tang and freeze dried filet mignon to Luna for years. Actually the way to kill a government funded space program is to insist that the program simply must have resources that are more expensive than congress is willing to provide. <br />
:Actually neither Drexler's nano-factories nor Ares V launchers are necessary to build a lunar base that can support people. Time and remote controlled equipment that neither eats nor drinks nor breaths can establish the infrastructure that can support people and allow the export of products that will pay for imports. That is perhaps fifty years before there are profitable exports, not quite so long before the considerable benefits of hands on work can aid the lunar enterprise. <br />
:All necessary remotely operated devices can be sent to Luna on moderate size rockets. The Delta IV can put 19000 pounds into low Earth orbit. A modest modification to make the rocket more appropriate for the low Earth orbit mission than the Geostationary orbit mission could improve on that. A useful unmanned space station that would provide a platform for vehicle assembly and refueling would allow 19000 pound payloads to be assembled with a fully fueled vehicle that would put 19000 pounds on Luna. <br />
:A useful unmanned space station would have a constantly rotating portion housing motors and solar cells communications and if necessary some structure and ballast that would increase the moment of inertia for the constantly spinning portion. There would be a spin up spin down portion to rotate on the same axis. It would have solar cells communications and a refueling and assembly platform. Cargoes of fuel and rockets to be refueled or assembled would dock with the spin up spin down portion while it is not rotating. This is a capability that was demonstrated early in the space program. The center of mass of the loaded platform would be adjusted to the common spin axis of the station. The platform would be spun up to a mere 20 centimeters per second squared radial acceleration and fuel would be transferred with no problem. <br />
:The two sections of the refueling station would be connected by magnetic bearings and an electric motor. There would no solid surface contact between the two and no need for lubricants. <br />
:Savings comes from not building Ares V nor maintaining launching facilities for Ares V or any other expensive heavy lift vehicle. More savings comes from a higher frequency of launch of medium lift rockets resulting (at least potentially) in lower unit cost. NASA does not do things this way because of an institutional bias toward using big rockets. There is some argument for using big rockets in all at once launches for manned Mars missions, but the expense should all be counted toward the manned Mars missions. A program of [[Bootstrapping Industry]] on Luna does not require big rockets. <br />
:This does not need to result in a smaller NASA. Spending the same money on cheaper per each missions results in more missions. <br />
===References===<br />
<references/><br />
[[category:Infrastructures]]</div>209.23.189.25https://lunarpedia.org/index.php?title=Reusable_Rockets&diff=13329Reusable Rockets2008-08-28T21:51:14Z<p>209.23.189.25: /* Reusable Rockets */</p>
<hr />
<div>= Reusable Rockets = <br />
One potential way to reuse rocket boosters or first stage rockets is to launch from the ocean as SeaLaunch does, and position the launch so that a handy island is down range just far enough for the reusable booster to land there without having to fly back to the launch point. Then it would make sense to expend some money making the engines efficient and reusable and not loose the investment with every launch. Recovering solid rocket motor casings at sea just does not seem to me to be saving much. <br />
:To recover and reuse a second stage a launch at sea might be positioned so that an island is just where the second stage would re-enter and fall to Earth after one orbit. <br />
:The problem with this scheme is that although the U.S. owns some islands in the Pacific, none of them is in any congressman's district. <br />
:An alternate reuse strategy is to pack parachutes on the first stage. Probably a first high speed parachute that leads out a second middle speed parachute that drags out a paraglider. The first two chutes would be expended. The first stage then glides down to a recovery vessel that is speeding along in the ocean to match forward velocity. Then the paraglider flares out to reduce downward velocity as it lands on an air mattress on the deck of the recovery vehicle. A robust engine that does not need very expensive refurbishing after every flight may be possible. <br />
<br />
[[category:Rocketry]]</div>209.23.189.25https://lunarpedia.org/index.php?title=Talk:Water&diff=13051Talk:Water2008-08-16T16:45:00Z<p>209.23.189.25: </p>
<hr />
<div>''Other substances, such as aluminum or magnesium and oxygen can be used for rocket fuel. We have plenty of those.'' <br />
<br />
Oxygen has been used for decades as rocket oxidizer. Although magnesium and aluminium are good fuels, and are used in solid rockets, they can not be used in a liquid rocket, as they have to be kept very hot to be a liquid, leading to compatibility issues with supercold LOX. An alternative would be to have a hybrid rocket: a tank of LOX, and a tube filled with metal powder. However, the metal powder will fall out the nozzle. This is why solid rockets use a binder to keep the fuels together. The binder will have to be shipped from Earth. [[User:T.Neo|T.Neo]] 08:42, 11 August 2008 (UTC)<br />
<br />
<br />
Response from Bryce: T.Neo raises a good point. Solid and even hybrid rocket fuel here on Earth is mixed with a binder, which is often a high hydrocarbon rubberlike substance. That's pretty pricey on the Moon and, again, we hate to "throw away" hydrogen (and carbon) in this way. Maybe given the vacuum and anhydrous environment of the Moon, we could do some sort of "sintering" process to cause our fuel to stick together until used, and yet have the oxidizer reach it when needed.<br />
<br />
The reason the metal fuel is in powder form is because there is more surface area. If the aluminium was just one solid sheet, the reaction with oxygen would create an impervious barrier of aluminium oxide, preventing further reaction. Sintering the fuel would, I imagine, decrease the surface area and lead to the same problem. But, maybe the ratio of fuel to binder could be changed, with the binder being just a thin layer holding the powder together. What would this material be? What about the remaining fuel left in cargo lander fuel tanks? [[User:T.Neo|T.Neo]] 07:43, 12 August 2008 (UTC)<br />
<br />
:That could be a possibility. NASA is currently working on ways to scavenge unused fuel from the lunar landers so it can be used in an outpost. I've heard mention of hybrid engines which would use hexagonal cross-section metal rods in addition to hydrogen/LOX in the combustion chamber to add additional boost, but that is for interplanetary/cislunar ships which would not land. - [[User:Jarogers2001|Jarogers2001]] 14:08, 12 August 2008 (UTC)<br />
<br />
Abundance of oxygen could be an advantage for a "direct ascent" lander. It does not have to carry the oxidiser for the return trip, only the fuel. I am weary about any potential hybrid/solid rocket for manned transportation. [[User:T.Neo|T.Neo]] 07:10, 13 August 2008 (UTC)<br />
===liquid aluminum / liquid oxygen rockets===<br />
T.Neo should not give up too easily on liquid aluminum / liquid oxygen rockets. The liquid oxygen in the tanks would be used to cool the combustion chamber wall in a tube wall construction design. So before it is injected into the combustion chamber it will be a hot gas. Liquid hydrogen is used to cool the combustion chamber wall of the space shuttle main engine. The temperature differences there are greater than there will be in the aluminum oxygen rocket. Oxygen is not as good a coolant as hydrogen so the aluminum oxygen rocket will not be able to run up to as high a temperature or pressure as the space shuttle main engine. The rocket would not reach that temperature any way because of all the excess oxydizer necessary to keep sufficient gas in the combustion chamber to serve as a working fluid. People at the following web sites think aluminum/oxygen rockets are worth considering:<br />
http://www.asi.org/adb/06/09/03/02/095/al-o-propellants.html <br />
and<br />
http://www.projectrho.com/rocket/rocket3c2.html <br />
===mass drivers===<br />
All of this rocket stuff is just a preliminary expedient anyway. See the [[Mass Drivers]] article to see what ought be the economic method of getting stuff from Luna to lunar orbit when things are more fully developed.--[[User:Farred|Farred]] 22:59, 13 August 2008 (UTC)<br />
<br />
I don't have a problem with cooling the engine, I have a problem with keeping the aluminium liquid, and keeping the LOX cold, all while trying to keep the rocket in one piece. The binder in use in a hybrid rocket can be a thin film holding the fuel together. Importing volatiles is not so hard. We can make lander stages out of volatiles, we can make our Earth Departure stages out of volatiles, so that when we crash them into the Moon to calibrate our tectonic sensors we can provide future generations with volatiles. The Ranger probes used balsa wood to cushion lunar impact. Why not send huge chunks of plastic to crash into the moon? No landers, etc. This approach could even be used to land "dumb" payloads on the Moon. Do not confuse "Reuseable" with "reuturn to Earth". I think Mass drivers are the way to go to lift payloads off the Moon, cargo at least. I was thinking of a rocket second stage, if not that, some sort of device for orbital manuvering. I think that a solar thermal rocket using LOx as a working fluid could fit the job nicely. [[User:T.Neo|T.Neo]] 12:30, 14 August 2008 (UTC)<br />
===problems, problems===<br />
:There is a tendency of lunar base enthusiasts to go off on tangents worrying about problems that turn out to be irrelevant and ignoring serious problems. This situation is a result of our ignorance. With what little information we have I am not convinced that the maintaining the aluminum liquid and oxygen liquid in separate tanks on one rocket vehicle will be the big problem. Lacking proper reference works at hand at the moment, I looked up a couple of web pages that incidentally touched on the liquid temperature of aluminum. Omni Technologies gives a temperature for melting their aluminum based brazing material as 582 – 604 degrees centigrade. http://www.omnibraze.com/wire.html A research paper by A. Gerlich et al. gives the melting point of an aluminum magnesium eutectic as 437 degrees centrigrade. http://www.materialsaustralia.com/Materials_Forum/Vol29/GP%2046.pdf With some aluminum, magnesium and silicon in the pot the melting temperature might be managably low. Vacuum insulation is not difficult to come by or maintain on Luna. Even though the actual fuel that is put into such a hypothetical rocket just prior to launch must be considerably hotter than the melting point to insure that some higher melting point phase does not freeze out to coat the inner surface of tubing, the temperature involved should not melt insulation materials available. <br />
:A concern that must be addressed is the tendency for metals from which one might otherwise construct a combustion chamber to burn away in a high temperature high pressure pure oxygen environment. I can not say off hand what alloy or ceramic might be suitable for the combustion chamber wall. There is also the problem of aluminum oxide particles in the rocket exhaust abrading the throat of the combustion chamber. Perhaps expendable ceramic inserts to line the combustion chamber throat would be called for. <br />
:My main point is that until there is more definite data, we can not completely rule out a liquid aluminum / liquid oxygen rocket. Have you got a rocket test stand in your garage that operates in a high vacuum? <br />
:Just putting in capital letters fixed the link to the Mass Drivers article. '''--FARTHERRED'''<br />
<br />
:Why not use powdered aluminum in a straight tube and feed it into the combustion chamber by pushing on the other end? Aluminum could disperse when blown by the oxygen. - [[User:Jarogers2001|Jarogers2001]] 03:04, 15 August 2008 (UTC)<br />
<br />
You mean push the powder into the combustion chamber? Could work. I am looking at this from the perspective of ACPC propellant. <br />
-Do away with Ammonium perchlorate oxidser, and turn the device into a hybrid rocket with oxygen oxidizer.<br />
-Reduce the amount of binder to a bare minimum.<br />
Yes, the binder has to be imported from Earth, but only a small amount is used. As I said in my previous comment, getting volatiles to the moon is not as hard as you might think. Even with some Aluminium/Magnesium/silicon fuel, I am unsure about what the rocket might be contructed of, etc. Remember how small the apollo lunar module was, getting off the Moon SSTO. Now, if there was a hybrid, with a mass driver accelerating a rocket powered second stage, the two could be much smaller then a pure rocket or pure mass driver system. This means that the colonists only need to build a mass driver that is half the length, and a rocket stage that is half the size. We have not tested aluminium rocket technology. The safest, cost effective way would be a hybrid rocket. No, I do not have a working test model in my garage, but I am working on it. I have several crazy propellant ideas. Now, where can I find some liquid Flourine? [[User:T.Neo|T.Neo]] 07:17, 15 August 2008 (UTC)<br />
===Pumping Aluminum Powder===<br />
In response to Jarogers2001’s suggestion of feeding powdered aluminum into the combustion chamber of a rocket<br />
:Let us take the transfer of powdered aluminum to the combustion chamber of a rocket one step at a time. First, if the aluminum powder were in a vertical cylinder opening at the bottom into the combustion chamber, that cylinder would need to be pressurized with a nonoxidizing gas to the same pressure as the combustion chamber to prevent the oxygen from the combustion chamber moving into the stored aluminum powder bringing the flame front with it. Otherwise the cylinder would be just a portion of the combustion chamber and not the type of rocket engine being discussed. To keep the aluminum powder from just falling into the combustion chamber prematurely there would need to be a door between the fuel chamber and the combustion chamber that would open or disintegrate into a number of pieces that could fall through the combustion chamber when the rocket was ignited. The aluminum would not need to be pushed into the combustion chamber, it would fall in. There would be very poor control of the rate of fuel injection. <br />
:Second, the aluminum powder could be pushed through a cylinder with a horizontal axis by an auger and fall at one end into the combustion chamber. Again, the aluminum storage chamber would need to be pressurized. <br />
:Third aluminum powder in cans could be pushed into the combustion chamber through a port with a set of seals preserving combustion chamber pressure. The cans, perhaps made of aluminum titanium alloy, would need to retain structural integrity just long enough get through the port seals, and then burn completely with their contents. <br />
:Fourth cans of aluminum powder could be added to the combustion chamber by a positive displacement pump having two rotors of two or more lobes each. Although such pumps are usually used for liquids they might serve for cans of aluminum powder. Check out an example at the Pump World web page. http://www.pumpworld.com/positive_displacement_pump_basic.htm A set of springs might be added to the pump so cans of aluminum powder would be positively ejected from the pump cavity as the cavity opens onto the combustion chamber rather than having the can squashed by the vane that tries to close the cavity. The ends of the rotor vanes might be lubricated with gold to prevent excessive blow-by. It would cost about twice as much as grease on Luna because in addition to transportation costs the raw material cost would be significant. The cost would be justified only if the rocket engine provided great advantages over competing types. <br />
:In summary, although it does not seem to be proven that pushing aluminum powder into the combustion chamber of a rocket is absolutely physically impossible, there does seem to be the lack of any great motivation for putting money into pursuing this idea.'''--FARTHERRED''' 11:43am central daylight time on the 16th of August</div>209.23.189.25https://lunarpedia.org/index.php?title=Talk:Water&diff=13040Talk:Water2008-08-14T20:52:04Z<p>209.23.189.25: spelling</p>
<hr />
<div>''Other substances, such as aluminum or magnesium and oxygen can be used for rocket fuel. We have plenty of those.'' <br />
<br />
Oxygen has been used for decades as rocket oxidizer. Although magnesium and aluminium are good fuels, and are used in solid rockets, they can not be used in a liquid rocket, as they have to be kept very hot to be a liquid, leading to compatibility issues with supercold LOX. An alternative would be to have a hybrid rocket: a tank of LOX, and a tube filled with metal powder. However, the metal powder will fall out the nozzle. This is why solid rockets use a binder to keep the fuels together. The binder will have to be shipped from Earth. [[User:T.Neo|T.Neo]] 08:42, 11 August 2008 (UTC)<br />
<br />
<br />
Response from Bryce: T.Neo raises a good point. Solid and even hybrid rocket fuel here on Earth is mixed with a binder, which is often a high hydrocarbon rubberlike substance. That's pretty pricey on the Moon and, again, we hate to "throw away" hydrogen (and carbon) in this way. Maybe given the vacuum and anhydrous environment of the Moon, we could do some sort of "sintering" process to cause our fuel to stick together until used, and yet have the oxidizer reach it when needed.<br />
<br />
The reason the metal fuel is in powder form is because there is more surface area. If the aluminium was just one solid sheet, the reaction with oxygen would create an impervious barrier of aluminium oxide, preventing further reaction. Sintering the fuel would, I imagine, decrease the surface area and lead to the same problem. But, maybe the ratio of fuel to binder could be changed, with the binder being just a thin layer holding the powder together. What would this material be? What about the remaining fuel left in cargo lander fuel tanks? [[User:T.Neo|T.Neo]] 07:43, 12 August 2008 (UTC)<br />
<br />
:That could be a possibility. NASA is currently working on ways to scavenge unused fuel from the lunar landers so it can be used in an outpost. I've heard mention of hybrid engines which would use hexagonal cross-section metal rods in addition to hydrogen/LOX in the combustion chamber to add additional boost, but that is for interplanetary/cislunar ships which would not land. - [[User:Jarogers2001|Jarogers2001]] 14:08, 12 August 2008 (UTC)<br />
<br />
Abundance of oxygen could be an advantage for a "direct ascent" lander. It does not have to carry the oxidiser for the return trip, only the fuel. I am weary about any potential hybrid/solid rocket for manned transportation. [[User:T.Neo|T.Neo]] 07:10, 13 August 2008 (UTC)<br />
===liquid aluminum / liquid oxygen rockets===<br />
T.Neo should not give up too easily on liquid aluminum / liquid oxygen rockets. The liquid oxygen in the tanks would be used to cool the combustion chamber wall in a tube wall construction design. So before it is injected into the combustion chamber it will be a hot gas. Liquid hydrogen is used to cool the combustion chamber wall of the space shuttle main engine. The temperature differences there are greater than there will be in the aluminum oxygen rocket. Oxygen is not as good a coolant as hydrogen so the aluminum oxygen rocket will not be able to run up to as high a temperature or pressure as the space shuttle main engine. The rocket would not reach that temperature any way because of all the excess oxydizer necessary to keep sufficient gas in the combustion chamber to serve as a working fluid. People at the following web sites think aluminum/oxygen rockets are worth considering:<br />
http://www.asi.org/adb/06/09/03/02/095/al-o-propellants.html <br />
and<br />
http://www.projectrho.com/rocket/rocket3c2.html <br />
===mass drivers===<br />
All of this rocket stuff is just a preliminary expedient anyway. See the [[Mass Drivers]] article to see what ought be the economic method of getting stuff from Luna to lunar orbit when things are more fully developed.--[[User:Farred|Farred]] 22:59, 13 August 2008 (UTC)<br />
<br />
I don't have a problem with cooling the engine, I have a problem with keeping the aluminium liquid, and keeping the LOX cold, all while trying to keep the rocket in one piece. The binder in use in a hybrid rocket can be a thin film holding the fuel together. Importing volatiles is not so hard. We can make lander stages out of volatiles, we can make our Earth Departure stages out of volatiles, so that when we crash them into the Moon to calibrate our tectonic sensors we can provide future generations with volatiles. The Ranger probes used balsa wood to cushion lunar impact. Why not send huge chunks of plastic to crash into the moon? No landers, etc. This approach could even be used to land "dumb" payloads on the Moon. Do not confuse "Reuseable" with "reuturn to Earth". I think Mass drivers are the way to go to lift payloads off the Moon, cargo at least. I was thinking of a rocket second stage, if not that, some sort of device for orbital manuvering. I think that a solar thermal rocket using LOx as a working fluid could fit the job nicely. [[User:T.Neo|T.Neo]] 12:30, 14 August 2008 (UTC)<br />
===problems, problems===<br />
:There is a tendency of lunar base enthusiasts to go off on tangents worrying about problems that turn out to be irrelevant and ignoring serious problems. This situation is a result of our ignorance. With what little information we have I am not convinced that the maintaining the aluminum liquid and oxygen liquid in separate tanks on one rocket vehicle will be the big problem. Lacking proper reference works at hand at the moment, I looked up a couple of web pages that incidentally touched on the liquid temperature of aluminum. Omni Technologies gives a temperature for melting their aluminum based brazing material as 582 – 604 degrees centigrade. http://www.omnibraze.com/wire.html A research paper by A. Gerlich et al. gives the melting point of an aluminum magnesium eutectic as 437 degrees centrigrade. http://www.materialsaustralia.com/Materials_Forum/Vol29/GP%2046.pdf With some aluminum, magnesium and silicon in the pot the melting temperature might be managably low. Vacuum insulation is not difficult to come by or maintain on Luna. Even though the actual fuel that is put into such a hypothetical rocket just prior to launch must be considerably hotter than the melting point to insure that some higher melting point phase does not freeze out to coat the inner surface of tubing, the temperature involved should not melt insulation materials available. <br />
:A concern that must be addressed is the tendency for metals from which one might otherwise construct a combustion chamber to burn away in a high temperature high pressure pure oxygen environment. I can not say off hand what alloy or ceramic might be suitable for the combustion chamber wall. There is also the problem of aluminum oxide particles in the rocket exhaust abrading the throat of the combustion chamber. Perhaps expendable ceramic inserts to line the combustion chamber throat would be called for. <br />
:My main point is that until there is more definite data, we can not completely rule out a liquid aluminum / liquid oxygen rocket. Have you got a rocket test stand in your garage that operates in a high vacuum? <br />
:Just putting in capital letters fixed the link to the Mass Drivers article. '''--FARTHERRED'''</div>209.23.189.25https://lunarpedia.org/index.php?title=Talk:Water&diff=13039Talk:Water2008-08-14T20:38:22Z<p>209.23.189.25: </p>
<hr />
<div>''Other substances, such as aluminum or magnesium and oxygen can be used for rocket fuel. We have plenty of those.'' <br />
<br />
Oxygen has been used for decades as rocket oxidizer. Although magnesium and aluminium are good fuels, and are used in solid rockets, they can not be used in a liquid rocket, as they have to be kept very hot to be a liquid, leading to compatibility issues with supercold LOX. An alternative would be to have a hybrid rocket: a tank of LOX, and a tube filled with metal powder. However, the metal powder will fall out the nozzle. This is why solid rockets use a binder to keep the fuels together. The binder will have to be shipped from Earth. [[User:T.Neo|T.Neo]] 08:42, 11 August 2008 (UTC)<br />
<br />
<br />
Response from Bryce: T.Neo raises a good point. Solid and even hybrid rocket fuel here on Earth is mixed with a binder, which is often a high hydrocarbon rubberlike substance. That's pretty pricey on the Moon and, again, we hate to "throw away" hydrogen (and carbon) in this way. Maybe given the vacuum and anhydrous environment of the Moon, we could do some sort of "sintering" process to cause our fuel to stick together until used, and yet have the oxidizer reach it when needed.<br />
<br />
The reason the metal fuel is in powder form is because there is more surface area. If the aluminium was just one solid sheet, the reaction with oxygen would create an impervious barrier of aluminium oxide, preventing further reaction. Sintering the fuel would, I imagine, decrease the surface area and lead to the same problem. But, maybe the ratio of fuel to binder could be changed, with the binder being just a thin layer holding the powder together. What would this material be? What about the remaining fuel left in cargo lander fuel tanks? [[User:T.Neo|T.Neo]] 07:43, 12 August 2008 (UTC)<br />
<br />
:That could be a possibility. NASA is currently working on ways to scavenge unused fuel from the lunar landers so it can be used in an outpost. I've heard mention of hybrid engines which would use hexagonal cross-section metal rods in addition to hydrogen/LOX in the combustion chamber to add additional boost, but that is for interplanetary/cislunar ships which would not land. - [[User:Jarogers2001|Jarogers2001]] 14:08, 12 August 2008 (UTC)<br />
<br />
Abundance of oxygen could be an advantage for a "direct ascent" lander. It does not have to carry the oxidiser for the return trip, only the fuel. I am weary about any potential hybrid/solid rocket for manned transportation. [[User:T.Neo|T.Neo]] 07:10, 13 August 2008 (UTC)<br />
===liquid aluminum / liquid oxygen rockets===<br />
T.Neo should not give up too easily on liquid aluminum / liquid oxygen rockets. The liquid oxygen in the tanks would be used to cool the combustion chamber wall in a tube wall construction design. So before it is injected into the combustion chamber it will be a hot gas. Liquid hydrogen is used to cool the combustion chamber wall of the space shuttle main engine. The temperature differences there are greater than there will be in the aluminum oxygen rocket. Oxygen is not as good a coolant as hydrogen so the aluminum oxygen rocket will not be able to run up to as high a temperature or pressure as the space shuttle main engine. The rocket would not reach that temperature any way because of all the excess oxydizer necessary to keep sufficient gas in the combustion chamber to serve as a working fluid. People at the following web sites think aluminum/oxygen rockets are worth considering:<br />
http://www.asi.org/adb/06/09/03/02/095/al-o-propellants.html <br />
and<br />
http://www.projectrho.com/rocket/rocket3c2.html <br />
===mass drivers===<br />
All of this rocket stuff is just a preliminary expedient anyway. See the [[Mass Drivers]] article to see what ought be the economic method of getting stuff from Luna to lunar orbit when things are more fully developed.--[[User:Farred|Farred]] 22:59, 13 August 2008 (UTC)<br />
<br />
I don't have a problem with cooling the engine, I have a problem with keeping the aluminium liquid, and keeping the LOX cold, all while trying to keep the rocket in one piece. The binder in use in a hybrid rocket can be a thin film holding the fuel together. Importing volatiles is not so hard. We can make lander stages out of volatiles, we can make our Earth Departure stages out of volatiles, so that when we crash them into the Moon to calibrate our tectonic sensors we can provide future generations with volatiles. The Ranger probes used balsa wood to cushion lunar impact. Why not send huge chunks of plastic to crash into the moon? No landers, etc. This approach could even be used to land "dumb" payloads on the Moon. Do not confuse "Reuseable" with "reuturn to Earth". I think Mass drivers are the way to go to lift payloads off the Moon, cargo at least. I was thinking of a rocket second stage, if not that, some sort of device for orbital manuvering. I think that a solar thermal rocket using LOx as a working fluid could fit the job nicely. [[User:T.Neo|T.Neo]] 12:30, 14 August 2008 (UTC)<br />
===problems, problems===<br />
:There is a tendencey of lunar base enthusiasts to go off on tangents worrying about problems that turn out to be irrelevant and ignoring serious problems. This situation is a result of our ignorance. With what little information we have I am not convinced that the maintaining the aluminum liquid and oxygen liquid in separate tanks on one rocket vehicle will be the big problem. Lacking proper reference works at hand at the moment, I looked up a couple of web pages that incidently touched on the liquid temperature of aluminum. Omni Technologies gives a temperature for melting their aluminum based brazing material as 582 – 604 degrees centigrade. http://www.omnibraze.com/wire.html A research paper by A. Gerlich et al. gives the melting point of an aluminum magnesium eutectic as 437 degrees centrigrade. http://www.materialsaustralia.com/Materials_Forum/Vol29/GP%2046.pdf With some aluminum, magnesium and silicon in the pot the melting temperature might be managably low. Vacuum insulation is not difficult to come by or maintain on Luna. Even though the actual fuel that is put into such a hypothetical rocket just prior to launch must be considerably hotter than the melting point to insure that some higher melting point phase does not freeze out to coat the inner surface of tubing, the temperature involved should not melt insulation materials available. <br />
:A concern that must be addressed is the tendency for metals from which one might otherwise construct a combustion chamber to burn away in a high temperature high pressure pure oxygen environment. I can not say off hand what alloy or ceramic might be suitable for the combustion chamber wall. There is also the problem of aluminum oxide particles in the rocket exhaust abrading the throat of the combustion chamber. Perhaps expendble ceramic inserts to line the combustion chamber throat would be called for. <br />
:My main point is that until there is more deffinite data, we can not completely rule out a liquid aluminum / liquid oxygen rocket. Have you got a rocket test stand in your garage that operates in a high vacuum? <br />
:Just putting in capital letters fixed the link to the Mass Drivers article. '''--FARTHERRED'''</div>209.23.189.25https://lunarpedia.org/index.php?title=Talk:Water&diff=13038Talk:Water2008-08-14T16:49:20Z<p>209.23.189.25: /* mass drivers */</p>
<hr />
<div>''Other substances, such as aluminum or magnesium and oxygen can be used for rocket fuel. We have plenty of those.'' <br />
<br />
Oxygen has been used for decades as rocket oxidizer. Although magnesium and aluminium are good fuels, and are used in solid rockets, they can not be used in a liquid rocket, as they have to be kept very hot to be a liquid, leading to compatibility issues with supercold LOX. An alternative would be to have a hybrid rocket: a tank of LOX, and a tube filled with metal powder. However, the metal powder will fall out the nozzle. This is why solid rockets use a binder to keep the fuels together. The binder will have to be shipped from Earth. [[User:T.Neo|T.Neo]] 08:42, 11 August 2008 (UTC)<br />
<br />
<br />
Response from Bryce: T.Neo raises a good point. Solid and even hybrid rocket fuel here on Earth is mixed with a binder, which is often a high hydrocarbon rubberlike substance. That's pretty pricey on the Moon and, again, we hate to "throw away" hydrogen (and carbon) in this way. Maybe given the vacuum and anhydrous environment of the Moon, we could do some sort of "sintering" process to cause our fuel to stick together until used, and yet have the oxidizer reach it when needed.<br />
<br />
The reason the metal fuel is in powder form is because there is more surface area. If the aluminium was just one solid sheet, the reaction with oxygen would create an impervious barrier of aluminium oxide, preventing further reaction. Sintering the fuel would, I imagine, decrease the surface area and lead to the same problem. But, maybe the ratio of fuel to binder could be changed, with the binder being just a thin layer holding the powder together. What would this material be? What about the remaining fuel left in cargo lander fuel tanks? [[User:T.Neo|T.Neo]] 07:43, 12 August 2008 (UTC)<br />
<br />
:That could be a possibility. NASA is currently working on ways to scavenge unused fuel from the lunar landers so it can be used in an outpost. I've heard mention of hybrid engines which would use hexagonal cross-section metal rods in addition to hydrogen/LOX in the combustion chamber to add additional boost, but that is for interplanetary/cislunar ships which would not land. - [[User:Jarogers2001|Jarogers2001]] 14:08, 12 August 2008 (UTC)<br />
<br />
Abundance of oxygen could be an advantage for a "direct ascent" lander. It does not have to carry the oxidiser for the return trip, only the fuel. I am weary about any potential hybrid/solid rocket for manned transportation. [[User:T.Neo|T.Neo]] 07:10, 13 August 2008 (UTC)<br />
===liquid aluminum / liquid oxygen rockets===<br />
T.Neo should not give up too easily on liquid aluminum / liquid oxygen rockets. The liquid oxygen in the tanks would be used to cool the combustion chamber wall in a tube wall construction design. So before it is injected into the combustion chamber it will be a hot gas. Liquid hydrogen is used to cool the combustion chamber wall of the space shuttle main engine. The temperature differences there are greater than there will be in the aluminum oxygen rocket. Oxygen is not as good a coolant as hydrogen so the aluminum oxygen rocket will not be able to run up to as high a temperature or pressure as the space shuttle main engine. The rocket would not reach that temperature any way because of all the excess oxydizer necessary to keep sufficient gas in the combustion chamber to serve as a working fluid. People at the following web sites think aluminum/oxygen rockets are worth considering:<br />
http://www.asi.org/adb/06/09/03/02/095/al-o-propellants.html <br />
and<br />
http://www.projectrho.com/rocket/rocket3c2.html <br />
===mass drivers===<br />
All of this rocket stuff is just a preliminary expedient anyway. See the [[Mass Drivers]] article to see what ought be the economic method of getting stuff from Luna to lunar orbit when things are more fully developed.--[[User:Farred|Farred]] 22:59, 13 August 2008 (UTC)<br />
<br />
I don't have a problem with cooling the engine, I have a problem with keeping the aluminium liquid, and keeping the LOX cold, all while trying to keep the rocket in one piece. The binder in use in a hybrid rocket can be a thin film holding the fuel together. Importing volatiles is not so hard. We can make lander stages out of volatiles, we can make our Earth Departure stages out of volatiles, so that when we crash them into the Moon to calibrate our tectonic sensors we can provide future generations with volatiles. The Ranger probes used balsa wood to cushion lunar impact. Why not send huge chunks of plastic to crash into the moon? No landers, etc. This approach could even be used to land "dumb" payloads on the Moon. Do not confuse "Reuseable" with "reuturn to Earth". I think Mass drivers are the way to go to lift payloads off the Moon, cargo at least. I was thinking of a rocket second stage, if not that, some sort of device for orbital manuvering. I think that a solar thermal rocket using LOx as a working fluid could fit the job nicely. [[User:T.Neo|T.Neo]] 12:30, 14 August 2008 (UTC)</div>209.23.189.25