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Super-heavy lift reusable launcher
"Martha Adams" wrote in message
news:gYenk.460$EL2.343@trnddc01... "Alan Erskine" wrote in message ... wrote in message ... Imagine a hydrogen oxygen rocket engine with an exit nozzle diameter of 17 meters in diameter, 36 meters long and produces a thrust of 53,300 tonnes with a specific impulse of 450 seconds. Not even if I were using drugs would I be able to imagine something so ridiculous as this. ============================================ "Ridiculous" is a very bad word, because it shuts-off thinking. I might go for "extravagant," but I'd like to point out, if it's out toward the far end of a good imagination, it's realistic, and I have guessed a scenario where the national effort would be directed to building a "small" fleet of these things. If you restart your thinking, maybe you can guess something too. 17 metre diameter rocket nozzle? Rocket engine over 100ft long? 53 THOUSAND tons of thrust? Regardless of what Mookie says about the possible, the practical must hold sway. Oh, and don't forget that you'll never (NEVER!) get an ISP of 450 at sea level; that means that Mookie is referring to a second stage (100 times the thrust of the S-II of the Saturn V)- the first stage would be even larger. Hell, we're arguing on these forums against the Ares V being too big. With as much thrust as Mookie suggests, you'd be able to launch a payload of 11,800 tonnes into LEO (based on the thrust of the second stage of the Saturn V). And then there's the support infrastructure - where do you build the engine (not to mention the propellant tanks and other structures). And where do you launch it; at The Cape or out at sea? The noise would be incredible, not to mention the probably seismic effects. Now, we can always assume ("never 'assume'; you make an 'ass' out of 'u' and 'me'" - The Odd Couple) that it's intended to be launched from the Moon or Mars or whatever, but geez, assumption leaves all sorts things in the ball park. Then again, the (proposed) nuclear fusion rocket would be even better (forget the effects of radiation) and then there's the (proposed) engine for the BIS Daedulus - nuclear BOMBS! Proposals are one thing; making them practical and useable are two entirely different things. And I didn't say it was impossible, just ridiculous. For the reasons above, Mookie's suggestion is unrealistic. Not impossible mind you, just unrealistic. If Mookie wanted to build his SSP's, it would be more economical to use the resourses of the Moon - combined with an electromagnetic launcher (they're planning that for the next series of U.S. Navy aircraft carriers - they use something called an 'ultracapacitor' to store electricity until the 'shot' - fascinating stuff). We don't need SSP's anyway. Check out a process called TDP; I first heard about it on the sci.space forums a couple of years ago (2003?) and I've been captivated by it ever since. It provides liquid fuels (diesel for trucks, buses, trains and ships; kerosene for aircraft and petrol [gasoline] for cars) for our transport needs without any changes in infrastructure from the refinery to the fuel tanks and no changes to engines either (the same doesn't apply to any other alternative energy - ethanol, electricity etc). It's also carbon negative (just in case all the doom-sayers [mainly the mass-media] are right about climate change) and can even be used to increase crop production by utilising something called 'biochar'. All at the same time. From landfill waste (food scraps, garden waste, plastic, rubber, waste oils and chemicals), agricultural waste (straw, chaff and animal waste) and even sewage (at the same time, water released from the plant contains no bacteria at all, let alone any that are alive, unlike normal sewage treatment). TDP also produces gas which can be burned in a gas turbine to produce electricity (I know, the gas turbine doesn't produce the electricity...). Starting with an investment of $1 billion Australian, Melbourne (3.8 million people) would be able to close all its landfills within five years of go-ahead. From then on, there would be over $200 million per year (profit from selling the TDP oil to refineries) to build additional TDP plants - Australia could stop using crude oil for transport fuels altogether within ten years of go-ahead, and export twice the amount of liquid transport fuels we currently consume (not just imports either, but all of it). Alternatively, the excess oil can be burned to displace coal for electricity generation (Victoria has about 500 years of brown coal at the current rate of consumption). The heat from the gas turbines is used in the process itself. Biochar has been shown to increase wheat production by two times and soy bean production by three times. Ten years after biochar starts being applied to fields, it could be used to double the productivity of over 32 million hectares (just starting with landfill waste-derived biochar and adding the crop residue from the 'treated' land to the TDP plant) and that's just with the biochar made from Melbourne's landfill waste. Mookie's off-target. |
#12
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Super-heavy lift reusable launcher
"Alan Erskine" wrote in message ... "Martha Adams" wrote in message news:gYenk.460$EL2.343@trnddc01... "Alan Erskine" wrote in message ... wrote in message ... Imagine a hydrogen oxygen rocket engine with an exit nozzle diameter of 17 meters in diameter, 36 meters long and produces a thrust of 53,300 tonnes with a specific impulse of 450 seconds. Not even if I were using drugs would I be able to imagine something so ridiculous as this. ============================================ "Ridiculous" is a very bad word, because it shuts-off thinking. I might go for "extravagant," but I'd like to point out, if it's out toward the far end of a good imagination, it's realistic, and I have guessed a scenario where the national effort would be directed to building a "small" fleet of these things. If you restart your thinking, maybe you can guess something too. 17 metre diameter rocket nozzle? Rocket engine over 100ft long? 53 THOUSAND tons of thrust? Regardless of what Mookie says about the possible, the practical must hold sway. Oh, and don't forget that you'll never (NEVER!) get an ISP of 450 at sea level; that means that Mookie is referring to a second stage (100 times the thrust of the S-II of the Saturn V)- the first stage would be even larger. Hell, we're arguing on these forums against the Ares V being too big. With as much thrust as Mookie suggests, you'd be able to launch a payload of 11,800 tonnes into LEO (based on the thrust of the second stage of the Saturn V). And then there's the support infrastructure - where do you build the engine (not to mention the propellant tanks and other structures). And where do you launch it; at The Cape or out at sea? The noise would be incredible, not to mention the probably seismic effects. Now, we can always assume ("never 'assume'; you make an 'ass' out of 'u' and 'me'" - The Odd Couple) that it's intended to be launched from the Moon or Mars or whatever, but geez, assumption leaves all sorts things in the ball park. Then again, the (proposed) nuclear fusion rocket would be even better (forget the effects of radiation) and then there's the (proposed) engine for the BIS Daedulus - nuclear BOMBS! Proposals are one thing; making them practical and useable are two entirely different things. And I didn't say it was impossible, just ridiculous. For the reasons above, Mookie's suggestion is unrealistic. Not impossible mind you, just unrealistic. If Mookie wanted to build his SSP's, it would be more economical to use the resourses of the Moon - combined with an electromagnetic launcher (they're planning that for the next series of U.S. Navy aircraft carriers - they use something called an 'ultracapacitor' to store electricity until the 'shot' - fascinating stuff). We don't need SSP's anyway. Check out a process called TDP; I first heard about it on the sci.space forums a couple of years ago (2003?) and I've been captivated by it ever since. It provides liquid fuels (diesel for trucks, buses, trains and ships; kerosene for aircraft and petrol [gasoline] for cars) for our transport needs without any changes in infrastructure from the refinery to the fuel tanks and no changes to engines either (the same doesn't apply to any other alternative energy - ethanol, electricity etc). It's also carbon negative (just in case all the doom-sayers [mainly the mass-media] are right about climate change) and can even be used to increase crop production by utilising something called 'biochar'. All at the same time. From landfill waste (food scraps, garden waste, plastic, rubber, waste oils and chemicals), agricultural waste (straw, chaff and animal waste) and even sewage (at the same time, water released from the plant contains no bacteria at all, let alone any that are alive, unlike normal sewage treatment). TDP also produces gas which can be burned in a gas turbine to produce electricity (I know, the gas turbine doesn't produce the electricity...). Starting with an investment of $1 billion Australian, Melbourne (3.8 million people) would be able to close all its landfills within five years of go-ahead. From then on, there would be over $200 million per year (profit from selling the TDP oil to refineries) to build additional TDP plants - Australia could stop using crude oil for transport fuels altogether within ten years of go-ahead, and export twice the amount of liquid transport fuels we currently consume (not just imports either, but all of it). Alternatively, the excess oil can be burned to displace coal for electricity generation (Victoria has about 500 years of brown coal at the current rate of consumption). The heat from the gas turbines is used in the process itself. Biochar has been shown to increase wheat production by two times and soy bean production by three times. Ten years after biochar starts being applied to fields, it could be used to double the productivity of over 32 million hectares (just starting with landfill waste-derived biochar and adding the crop residue from the 'treated' land to the TDP plant) and that's just with the biochar made from Melbourne's landfill waste. Mookie's off-target. ============================================== I understand some people need small ideas. Maybe some personal environment causes that. But size can have useful consequences, not to say Mookie proposes a whole new topic area for space opera. For my part, the more I think on these very large machines, the better I feel about it. At the least, it's a remedy for the inner vacuum I've been feeling since Apollo was killed to free up a little money for the Vietnam war. A booster so large its liftoff has seismic consequences. Wonderful! How close to this thing lifting off could you be and survive to tell of it? *That* is where I'd like to watch it from. A good thing about so much hydrogen and oxygen is, it burns without creating pollution. (But I think the launch site might be kind of foggy for a day or two.) The problems I see are, 1) where does the energy come from that makes all that fuel? And, 2) how do you store that much cryogenics stuff? I can see a rapid evolution of high-speed pump tech in this large-booster technology. I like big ideas, but few so big are realistic. This one has made my day. Titeotwawki -- mha [sci.space.policy 2008 Aug 08] |
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Super-heavy lift reusable launcher
On Aug 9, 9:00*am, "Alan Erskine" wrote:
"Martha Adams" wrote in message news:gYenk.460$EL2.343@trnddc01... "Alan Erskine" wrote in message ... wrote in message .... Imagine a hydrogen oxygen rocket engine with an exit nozzle diameter of 17 meters in diameter, 36 meters long and produces a thrust of 53,300 tonnes with a specific impulse of 450 seconds. Not even if I were using drugs would I be able to imagine something so ridiculous as this. ============================================ "Ridiculous" is a very bad word, because it shuts-off thinking. *I might go for "extravagant," but I'd like to point out, if it's out toward the far end of a good imagination, it's realistic, and I have guessed a scenario where the national effort would be directed to building a "small" fleet of these things. *If you restart your thinking, maybe you can guess something too. 17 metre diameter rocket nozzle? *Rocket engine over 100ft long? *53 THOUSAND tons of thrust? * http://ntrs.nasa.gov/archive/nasa/ca...973065121..pdf This is only 70x larger than the M1 - which was built and test fired - which means the size of the engine is about 8 times the diameter of M1 with the same area ratios and so forth. The real issue is the size of the turbo machinery. Scaling laws for such machinery show that we can make something the size needed. After all we already make turbomachinery and engines the size of the turbomachinery now anyway in other applications. There is no reason in principle that we cannot make rocket engines the size indicated. http://people.bath.ac.uk/ccsshb/12cyl/ Look at the size of the engine here. There is no reason we cannot build turbomachinery on a comparable scale. http://www.flickr.com/photos/nhodges...7601337385711/ Check out the size of this wind turbine http://www.organiclightsculptures.co...d-turbine..jpg A careful analysis of the details involved reveals no reason we cannot in principle build airframes the size needed, turbomachinery the size needed, or rocket nozzles the size needed. We already build ships that size and components that size - routinely... Regardless of what Mookie says about the possible, Its not me saying it, its DOD and then NASA saying it - in declassified literature that's over 50 years old. A quick look at the largest intricate machinery we build today indicates that we have the means to make turbomachinery nozzles and airframes of the requisite size. In fact, a careful review of the scaling laws associated with cost, indicates this is nearly the optimal size. the practical must hold sway. * 2 and 3 meter diameter pistons in diesel engines, 20 meter diameter flow nozzles in turbines, 100 meter impeller blades in other turbines.. these things are ROUTINELY built today. The scale isn't the problem. Create turbomachinery along the lines shown in the M1 on the appropriate scale - computer model the details to avoid the problems the F1 had with vibrations - and you're there man. Oh, and don't forget that you'll never (NEVER!) get an ISP of 450 at sea level; Obviously this is an average over the entire flight cycle which is easily achieved. Clearly a prelminary study is not the same as a complete study. haha.. So, alan is grasping at straws trying to present things as they are not. Fact is, a detailed engineering analysis would next do a calculus of variation analysis to determine ideal staging fractions and so forth. When that is done in order to increase mass flow rate (and hence thrust) at lift off - using minimal turbormachinery - you don't need high Isp (specific impulse) That's why they use SRBs on the shuttle. On this vehicle you do something more advanced . Something that has been suggested by rocket designers for 50 years. haha.. Namely mix methane solids in with the hydrogen to create a milkshake like slurry. Here's a recent (11 year old) review http://sbir.grc.nasa.gov/launch/GELLED.htm Mix methane/hydrogen in with your hydrogen - and layer it so the propellant is denser at the bottom of the tank. This gives you more propellant and better structural fraction at lift off - and you start out around 380 sec Isp and end up 465 Isp at the end - this is a way to modulate fuel flow rate and thrust - with very little change in turboequipment - which makes the system more reliable. Since you can optimize chamber pressure and do a number of other things when you do this trick - it produces a vastly superior system.. I didn't do all these calculations, but obviously I will as I proceed. In any event, clearly a 450 sec Isp over the entire flight cycle in this preliminary analysis is well justified. that means that Mookie is referring to a second stage (100 times the thrust of the S-II of the Saturn V)- the first stage would be even larger. No it doesn't. It means I'm referring to the entire ascent curve and averaging the Isp to get a preliminary estimate of vehicle size and so forth. The level of detail you're talking about comes next - you do a calculus of variation - with Isp compensated for altitude along the ascent profile and vary that profile to optimize it - then you vary the stage separation to optimize that - then, you vary the propellant mix as described to optimize that - and then do that spin over and over again, until you close in on the optimal stage fractions, and so forth. The point is, 1) the stage fractions will be within 10% of those already given, 2) the Isp will likely be higher ON AVERAGE than the AVERAGE given. Hell, we're arguing on these forums against the Ares V being too big. * So? Its mission requirements are different. With as much thrust as Mookie suggests, you'd be able to launch a payload of 11,800 tonnes into LEO (based on the thrust of the second stage of the Saturn V). * This vehicle, if you actually use the rocket equation with understanding will put over 50,000 tons into LEO - and 10,000 tons into GEO - or send 5,000 tons directly to the moon - and return it - or 5,000 tons to Mars and return it - and recover all the pieces involved. And then there's the support infrastructure - where do you build the engine (not to mention the propellant tanks and other structures). You build the supply chain for it. The first step is to get the money. That's done by building a terrestrial based solar hydrogen production unit that hydrogenates coal and produces 200,000 b/d of gasoline, diesel fuel and jet fuel. The $8 billion facility, using waste coal on a 500 sq km spent coal field - generates $7 billion per year in free cash flow - of which only 40% is leveraged to raise the original $8 billion. The remaining $4.2 billion in free cash flow is directed toward building other facilities, and R&D on interesting projects - like this one. I start with a warchest of about $50 million - and contact folks like Enercon http://www.enercon.de/en/_home.htm to build large airframe parts or Aioi Works of Japan's Diesel United for large turbomachinery,actuators, hydraulics and so forth or Sumitomo Heavy Industries for airframe and so forth http://en.wikipedia.org/wiki/Knock_Nevis spend a few tens of millions of dollars to detail things out - and by that time, I have a half dozen facilities operating - generating $30 billion per year in free cash flow for me - and from that I start buying up or partnering with - creating a consortium - to build the supply chain needed for building maintaining and operating this fleet- and its payloads (power satellites initially) Along the way a subscale version of the spacecraft is built that lofts a mere 500 tons to LEO - this orbits subscale powersats, but more importantly it lofts large numbers of large comsats that provide the world with a global wireless internet service - 50 billion channels - each channel sold on average for $6 per year - generating $300 billion per year - in free cash flow - the system costing less than $60 billion to build. This adds to the cash warchest. . *And where do you launch it; at The Cape or out at sea? * I have an equatorial island chain chosen owned by Indonesia. The islands are uninhabited, and the Indonesian government would be very keen on developing them, if they got to build a portion of it, and have nationals operate it. The first stage booster would re-enter and land near Manus - the falls on the Amazon river. There, the Brazilian government would allow the operation of a rocket field. The booster lands, is refueled and 'bounced back' to the launch center as described above. The Manus equatorial facility also operates a launch complex, with its booster coming down in Gabon - on the Haut-Ogooué Province - using the well-established cargo ships that support the mining industry there to bring in supplies. I would build the ships and launch infrastructure and parts in Asia, and float them - like off shore drilling platform parts - to shore side facilities where they would then be assembled into a launch center. The Brazilian facility would be floated up the Amazon,and the Gabon faclity would be floated up the Congo. http://www.diamondoffshore.com/ourCo...erigbasics.php Watch these videos to get an idea of how that works. The noise would be incredible, Yes. not to mention the probably seismic effects. http://www.diamondoffshore.com/ourCo...erigbasics.php Since we already use siesmic detectors to detect the launch of ballistic missiles, I am absolutely certain that these rockets will also be detected that way. Obviously the ability to detect these missiles seismically has no bearing on their practicality or utility in developing space based assets off world.. Now, we can always assume ("never 'assume'; you make an 'ass' out of 'u' and 'me'" - The Odd Couple) that it's intended to be launched from the Moon or Mars or whatever, Obviously, rockets built on Earth have been used to land people on the moon and then carry them back to Earth. Clearly, a 10,000 ton payload on a lunar free return trajectory, with all parts reusable - has the capacity to establish a significant transport capability between Earth and moon. Ditto for Earth and Mars. Of course this isn't the reason it was orignally built - but it is easily adapted to this purpose. but geez, assumption leaves all sorts things in the ball park. * ??? so, you are saying because alternatives to this proposed system pale in comparison to it we shouldn't do it? No matter how much money is made generating energy and communications off world using it? Obviously your idea makes no sense whatever. Then again, the (proposed) nuclear fusion rocket would be even better We don't know how to build fusion rockets - excepting nuclear pulse rockets that have fission triggers. (forget the effects of radiation) Why? Detractors won't. Plainly this system has none of those shortcomings. Clearly successfully operating these vehicles without incident establishes the need for super heavy lift capacity - while showing its safety. Obviously this is the first step to even larger lift capacity. and then there's the (proposed) engine for the BIS Daedulus - nuclear BOMBS! * The only fusion reaction we've been able to reliably engineer. Proposals are one thing; making them practical and useable are two entirely different things. Right, and the obvious way to achieve these later goals is to take a step toward them - with an intermediate goal. Clearly the proposed super launcher is that step. And I didn't say it was impossible, That is wise. just ridiculous. Why? *For the reasons above, None of those hold water. Mookie's suggestion is unrealistic. No it isn't. *Not impossible mind you, Agreed. just unrealistic. Not at all - in fact application of the scalaing laws and examination of the skill sets already out there in the world indicate this is nearly an optimal size. Sure, subscale systems will be built and tested - and likely find use in space launch and as tenders to larger payloads launched by the heavies - but these will be the workhorses until better engines are built - laser engines, and fusion engines as you pointed out. If Mookie wanted to build his SSP's, it would be more economical to use the resourses of the Moon - No it wouldn't. combined with an electromagnetic launcher How do you plan to get it up there? (they're planning that for the next series of U.S. Navy aircraft carriers - yes, electromagnetic rail guns - they'll offload the research by painting pretty pictures (remember when nuclear power would be too cheap to meter - that's when the DOD needed money for nuclear research) - and when they got what they wanted, they'll classify it and deny they ever said anything about it - and call anyone who reminds them of it - crazy or misinformed. lol. launchers of the type you envision have a number of interesting applications - and evne interesting space applications. But starting from where we are, it makes a lot more sense to have Sumitomo think about the airframe and Aioi think about the turbomachinery and rocket nozzle - and let diamond offshore think about big ass test stands and launch centers - if you want to actually build something today that works at a reasonable cost. Once your shipping 5,000+ metric tons to the moon every day - THEN you can think about what the benefit of a rail gun is. But, once you've got this sort of capacity on orbit, it makes more sense to use rail guns on Ceres or other rich asteroids and send a stream of material back to Earth orbit - and bring it into orbit here - use teleoperated robots in orbiting factories placed by these rockets, and solar power from satellites put up by these rockets to process that stuff into consumer goods, food and fiber - and deorbit it directly to consumers. With the profits from that operation, then you expand space launch to include a laser rocket ship in every garage -and then build space homes on orbit - but not before building and deorbiting cloud nine floating cities - to provide refuge for those stuck in bad places. they use something called an 'ultracapacitor' to store electricity until the 'shot' - fascinating stuff). Yep, I worked at Ohio State with Dr. Turchi, we had a room filled with capacitors that we charged up at night when everyone was asleep, and then shorted them through a variety of interesting stuff we built at the machine shop. We compressed deplete uranium in MHD tests, and we fired some rail guns - this was back in the 80s. So, I know a little about this subject. The problem is, that's not where you start. You start with the sort of vehicles I'm talking about, plugged into the sort of program I'm talking about. You start solving the world's energy needs, and then its raw material needs, then its food and fiber needs, its job needs, its communications and financial service needs - all iwth space based assets and off world resources. This is the way to proceed. We don't need SSP's anyway. * Yes we do. Check out a process called TDP; This is a way to do coal to liquids. The problem is where do you get your hydrogen? and oxygen? If you get your hydrogen from the shift reaction - you make 44 tons of CO2 for each ton of hydrogen you use. And then make more CO2 running the TDP process - BEFORE you even burn the fuel. Yeilds are as a result, very low. If you get your hydrogen and oxygen from the electrolytic reduction of water, and get your heat and electricity from either a solar or nuclear source - then you don't have any pollution and you have far higher yeilds. This is what I do!! http://www.usoal.com haha.. This is the first step. I use very low cost solar collectors, to make hydrogen and oxygen, then use direct hydrogenation processes to convert coal into liquids very efficiently. Its ludicrous to say TDP will solve our energy problems, since TDP doesn't create a primary source of energy. It NEEDS a primary source of energy to work. If you use coal as the primary source, or a combination of coal and natural gas - you are adding to the carbon burden of our air,and decreasing the value of coal. By tapping into a pollution free source of primary energy - like nuclear or solar - TDP is a step in a direct hydrogenation process that increases coals value by adding solar energy to it - while reducing our carbon footprint. Check it out - using my approach of tapping into solar to make hydrogen and oxygen from sunlight and water - we convert 5.5 bilion tons of coal each year into 38 billion barrels of gasoline, diesel fuel and jet fuel. We eliminate 18 bilion tons of carbon dioxide - by supplying 867 million tons of hydrogen to the coal fired plants to replace teh coal - and eliminate our need for conventional oil. I first heard about it on the sci.space forums a couple of years ago (2003?) and I've been captivated by it ever since. * Its a chemcial conversion process - not a primary energy source. How you power it determines whether or not it can be beneficial. Power it with my solar panels, and it makes sense - power it with coal and it makes things worse. It provides liquid fuels (diesel for trucks, buses, trains and ships; kerosene for aircraft and petrol [gasoline] for cars) for our transport needs without any changes in infrastructure from the refinery to the fuel tanks and no changes to engines either (the same doesn't apply to any other alternative energy - ethanol, electricity etc).. It's also carbon negative (just in case all the doom-sayers [mainly the mass-media] are right about climate change) and can even be used to increase crop production by utilising something called 'biochar'. Converting biomass into industrial fuels starves billions, lowers food quality, while increasing the cost of those fuels it makes. Converting coal into industrial fuels, increases electricity prices, creates electricity shortages, impoverishes the coal and utlities, while increasing the cost of liquid fuels while increasing pollution.. Using solar energy generated at 1/5th cent per kWh - to reduce water into hydrogen and oxygen -and using the hydrogen to replace coal in stationary power plants, while converting the released coal to liquid fuels with more hydrogen, increases teh value of coal, and reduces the cost of liquid fuels - while eliminating pollution. Furthermore, low cost hydrogen combined with air makes fertilizer at very low cost increasing volume and quality of food while reducing its costs. Finally, low cost solar water desalination, creates water at extremely low cost - allowing the irrigation of marginal lands and abundant water everywhere - increasing quality of life, lowering water costs,and increasing crop yeilds. All at the same time. You have ignored where the primary energy is coming from. Details count, and this is an important detail. TDP is a chemical process that is very efficient - and I use a version of it in my direct coal hydrogenation processes. Howeve,r HOW its powered, WHAT it is used for - determines its ultimate utility. Now, obviously generating hydrogen from sunlight is the best way to go. Clearly, once large tracts of solar collectors are in place,they are easily improved by adding a bandgap matched laser beam on orbit to illuminate the panels 24/7 - Plainly this is an obvious next step once a number of coal-to-liquid facilities are built. http://www.bni.co.id/Portals/0/Document/Coal.pdf http://www.mitrais.com/mining/miningNews060818.asp From landfill waste (food scraps, garden waste, plastic, rubber, waste oils and chemicals), agricultural waste (straw, chaff and animal waste) and even sewage (at the same time, water released from the plant contains no bacteria at all, let alone any that are alive, unlike normal sewage treatment). Humanity today uses 28.3 billion barrels of liquid fuels. It takes liquid fuel to make plastics, paper, and other waste. So, the volume of waste is far smaller than the volume of fuel we use. Converting that waste may be a good way to get rid of the waste by reusing it, but in total, it does little to change our energy supply situation. Furthermore, by focusing on waste streams which have a very high cost of recovery - we increase the cost of liquid fuels- which is fine by the oil companies - but not pointing us in the right direction. From 1870 to 1960 the price of oil dropped 5% per year throughout the entire period. A barrel fo oil in the 1950s and 60s cost less than a gallon of gas does today!! Since the US peaked in oil output in the 1970s our economy has suffered tremendously, and the price of oil has risen at an average compoound rate of 11% - nothing that has been seriously proposed challenges this view. All those programs that have the potential to challenge the price of oil today - and put us back on a trend toward low cost energy - are opposed and marginalized by a dedicated cadre of people who know better. Why? Because it undercuts the value of oil that's why. Ultra-low-cost terrestrial solar power - making hydrogen for coal conversion - reduces the cost of oil and provides more oil than we use today. Management of this technology allows us to sustain 7% or more increases per year in energy use worldwide, while reducing our carbon footprint - High temperature nuclear reactors - making hydrogen for coal conversion - achieve much the same ends. Using wastes and biomass - is at best marginal and raises the cost of food. . Wind power is at best marginal. Coal to liquid using shift reaction - triples pollution levels and wastes 2/3 of our coal while raising the price of oil and dpressing the price of coal. TDP also produces gas which can be burned in a gas turbine to produce electricity (I know, the gas turbine doesn't produce the electricity.). TDP is a chemical process - its not a source of primary energy. You need a carbon source and a hydrogen source. Solar provides that - without the solar source this is not a solution by itself. Starting with an investment of $1 billion Australian, Melbourne (3.8 million people) would be able to close all its landfills within five years of go-ahead. *From then on, there would be over $200 million per year (profit from selling the TDP oil to refineries) to build additional TDP plants - Australia could stop using crude oil for transport fuels altogether within ten years of go-ahead, and export twice the amount of liquid transport fuels we currently consume (not just imports either, but all of it). Alternatively, the excess oil can be burned to displace coal for electricity generation (Victoria has about 500 years of brown coal at the current rate of consumption). *The heat from the gas turbines is used in the process itself. http://www.environment.gov.au/soe/20...30/index..html Over this period 3.8 million australians used 970 million GJ of energy. Converted to oil at 6.1 GJ per barrel we have 159 million barels. At $200 australian per barrel we have $31.8 billion Australian. Now, your TDP program that converts the waste from those 3.8 milion australians to $0.2 bilion worth of liquid fuels - may be a good thing to do - but it isn't even a drop in the proverbial bucket. furthermore since the costs of collecting the waste - which was off- loaded to the government in order to make the profits (there was a political fight about that in melbourne) you are ignoreing the fact that this source of oil is MORE costly than buying it today. That's why the oil companies don't object to it. There's not enough made to really challenge the market price, and the cost of production is way higher. Not so with solar assisted conversion of coal at $8.57 per barrel - that's why you don't hear about it much. Biochar has been shown to increase wheat production by two times and soy bean production by three times. * Depends on the details - biochar can contain metals and radioactive materials in greater abundance than isnaturally found in soil. http://newenergynews.blogspot.com/20...economics.html Even if this is resolved, it doesn't change the fundamentals. Yes, we might be able to process our wastes in this way to make our economy slightly more efficient - by less than 1% - but it will cost far more than 1% of what we spend on generating energy to do -(which is why it hasn't been done) it won't materially affect our supply situation (you need waste made from energy processes in the first place for it to work) - so its not the answer as you wrongly say. Its a useful chemical process - one I have adapted to my systems - but you need to ask the basics. Where are you getting the energy and what does it cost? solar panels and coal combine to create a real challenge to the oil monopolies and have a real chance to bring costs down while reducing carbon emissions. once you have large solar arrays beaming bandgap matched laser energy to those arrays is an obvious way to increase their output of hydrogen, and create a hydrogen economy. improved optics on the laser powersats provide a means to eventually displace or augment hydrogen with laser power networks. Ten years after biochar starts being applied to fields, it could be used to double the productivity of over 32 million hectares (just starting with landfill waste-derived biochar and adding the crop residue from the 'treated' land to the TDP plant) and that's just with the biochar made from Melbourne's landfill waste. If we took ALL our wastes and processed them into liquid fuels, and used biochar cleaned of metals and radioactives to cover our fields, we'd increase our efficiency by about 1% - and cover about 20% of our fields - our basic supply situation won't be materially affected. if we however cover 210,000 sq miles of mine lands in deserts (owned by a handful of people) with solar collectors at $0.07 per peak watt - we would make 3.34 billion tons of hydrogen from 30 billion tons of water each year - enough to displace all fossil fuels everywhere - at a cost equivalent to $4 per barrel. Before that however, we will begin by converting waste coal to oil with hydrogen and oxygen made with solar collectors covering stripped out surface mines - using cleaned up run off water for the hydrogen source - and make oil at $8 per barrel. As the system expands, we displace coal in coal fired power plants with hydrogen, eliminating carbon emissions - and use hydrogen with that coal to make more liquid fuels at $9 per barrel. Converting ALL coal fired power plants to hydrogen, and all stranded coal to liquid fuels, generates 38 billion barrels of liquid fuels per year - more than is currently consumed. Which means, prices willl drop for liquid fuels! Economies will expand. Within 15 years of general expansion, there will be a NEED to take those converted surface mines and increase their power output 15 times - by orbiting solar power satellites to feed them bandgap matched laser energy - and increase the energy supplies of this world to 15x their current level. When the world has grown to need more energy it wil then be supplied by advanced lasers beaming energy directly to users anywhere. Mookie's off-target.- Hide quoted text - No you are. You droned on and on and on about TDP - but proved incapable of seeing the essential fact that TDP is a chemical conversion process, not a source of primary energy. It needs a source of hydrogen and oxygen adn carbon to work. Biomass can be that source of carbon - but the shift reaction is typically the source of hydrogne - and when that's the case, its a dirty process indeed. Details count, when you don't get the details right, you are off target. This has been your problem from the outset. You really need to address it in yourself, before calling me names! lol. - Show quoted text - |
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Super-heavy lift reusable launcher
On 9 Aug, 12:33, wrote:
You are assuming that heavy lift is need for SSP. In fact what you require is the phase locking of small (a few Kw) units. Not when you look at lowest system cost. * There are cost differences when scale changes. * While it is feasible to build on the scale you speak of, it is not AS cost effective. * Demonstration projects using subscale systems - will certainly be built as you suggest. I am not talking about a sub scale system. Phase linking produces a full size system. There is one other point too. The system must be engineered to fail soft. This means that we need to divide up both solar power and computer power. The Internet is composed of a lot of small units. The Internet has never failed even if individual units have. The optimal size for a transportation system is far from being clear cut. Weight goes up as L^3 whereas strength goes up only as L^2. Large units go better through the lower atmosphere, bur small units reenter better. I think we need to concentrate on $/Kg at LEO and on building an ion drive from LEO to GEO. Plus of course material from space. The size I propose here is nearly optimal to transition from chemical launcher, to chemical/laser launcher, and deep space laser probes, and laser recovery of asteroidal feedstock. haha.. *even at 200 GW per satellite - which is broken down using conjugate optics into many many beams some as small as 10 kW - you still have to combine 100s of satellites to do heavy lifting with laser energy - so 200 GW satellite size WILL also operate in phase locked mode - sharing a common pilot beam from a common receiver to usefully combine energies to do heavy lifting. As I said $/Kg not Kg at one go. You need to ask the cost of the TOTAL weight. Can the weight be reduced by contributions from space? I am not convinced you need more than 1000Kg at one go. What's interesting is if you look at the consumption curve of each person throughout the day and by season at each latititude in an industrial society, and then you shift that curve by longitude and latitutde for each person - and then sumall the component curves - to get a global energy demand curve - you end up with something like 210 TW average power - which peaks at over 300 TW and drops to less than 100 TW - throughout the day. * * This means there will be 1,500 satellites of this size!! *So, they'll certainly operate in a variety of modes - including combining their outputs for space workmostly. Harvesting asteroids, sending out space probes, sending out interstellar probes, and so forth. If you choose a laser you can in fact supplement terrestrial photovoltaics from space. This is quite interestin. I think you wil find that peak demand tends to be daylight hours. Space would be very useful in the early evening. This means that there are certain times of the day that you'll have the 33 TW available for launch for 10 minutes or so at a time. *You'll be limited to launching fewer than 6 vehicles per day - once your system is fully use and integrated into the world's economy. Ultimately - 100 or so of the 200 GW satellites will be permanently dedicate to supporting space operations.- Hide quoted text - - Ian Parker |
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Super-heavy lift reusable launcher
On Aug 9, 10:31*am, "Martha Adams" wrote:
"Alan Erskine" wrote in message ... "Martha Adams" wrote in message news:gYenk.460$EL2.343@trnddc01... "Alan Erskine" wrote in message ... wrote in message .... Imagine a hydrogen oxygen rocket engine with an exit nozzle diameter of 17 meters in diameter, 36 meters long and produces a thrust of 53,300 tonnes with a specific impulse of 450 seconds. Not even if I were using drugs would I be able to imagine something so ridiculous as this. ============================================ "Ridiculous" is a very bad word, because it shuts-off thinking. *I might go for "extravagant," but I'd like to point out, if it's out toward the far end of a good imagination, it's realistic, and I have guessed a scenario where the national effort would be directed to building a "small" fleet of these things. *If you restart your thinking, maybe you can guess something too. 17 metre diameter rocket nozzle? *Rocket engine over 100ft long? *53 THOUSAND tons of thrust? *Regardless of what Mookie says about the possible, the practical must hold sway. *Oh, and don't forget that you'll never (NEVER!) get an ISP of 450 at sea level; that means that Mookie is referring to a second stage (100 times the thrust of the S-II of the Saturn V)- the first stage would be even larger. Hell, we're arguing on these forums against the Ares V being too big. With as much thrust as Mookie suggests, you'd be able to launch a payload of 11,800 tonnes into LEO (based on the thrust of the second stage of the Saturn V). *And then there's the support infrastructure - where do you build the engine (not to mention the propellant tanks and other structures). *And where do you launch it; at The Cape or out at sea? *The noise would be incredible, not to mention the probably seismic effects. Now, we can always assume ("never 'assume'; you make an 'ass' out of 'u' and 'me'" - The Odd Couple) that it's intended to be launched from the Moon or Mars or whatever, but geez, assumption leaves all sorts things in the ball park. *Then again, the (proposed) nuclear fusion rocket would be even better (forget the effects of radiation) and then there's the (proposed) engine for the BIS Daedulus - nuclear BOMBS! Proposals are one thing; making them practical and useable are two entirely different things. And I didn't say it was impossible, just ridiculous. *For the reasons above, Mookie's suggestion is unrealistic. *Not impossible mind you, just unrealistic. If Mookie wanted to build his SSP's, it would be more economical to use the resourses of the Moon - combined with an electromagnetic launcher (they're planning that for the next series of U.S. Navy aircraft carriers - they use something called an 'ultracapacitor' to store electricity until the 'shot' - fascinating stuff). We don't need SSP's anyway. *Check out a process called TDP; I first heard about it on the sci.space forums a couple of years ago (2003?) and I've been captivated by it ever since. *It provides liquid fuels (diesel for trucks, buses, trains and ships; kerosene for aircraft and petrol [gasoline] for cars) for our transport needs without any changes in infrastructure from the refinery to the fuel tanks and no changes to engines either (the same doesn't apply to any other alternative energy - ethanol, electricity etc). It's also carbon negative (just in case all the doom-sayers [mainly the mass-media] are right about climate change) and can even be used to increase crop production by utilising something called 'biochar'. All at the same time. From landfill waste (food scraps, garden waste, plastic, rubber, waste oils and chemicals), agricultural waste (straw, chaff and animal waste) and even sewage (at the same time, water released from the plant contains no bacteria at all, let alone any that are alive, unlike normal sewage treatment). TDP also produces gas which can be burned in a gas turbine to produce electricity (I know, the gas turbine doesn't produce the electricity...). Starting with an investment of $1 billion Australian, Melbourne (3.8 million people) would be able to close all its landfills within five years of go-ahead. *From then on, there would be over $200 million per year (profit from selling the TDP oil to refineries) to build additional TDP plants - Australia could stop using crude oil for transport fuels altogether within ten years of go-ahead, and export twice the amount of liquid transport fuels we currently consume (not just imports either, but all of it). Alternatively, the excess oil can be burned to displace coal for electricity generation (Victoria has about 500 years of brown coal at the current rate of consumption). *The heat from the gas turbines is used in the process itself. Biochar has been shown to increase wheat production by two times and soy bean production by three times. *Ten years after biochar starts being applied to fields, it could be used to double the productivity of over 32 million hectares (just starting with landfill waste-derived biochar and adding the crop residue from the 'treated' land to the TDP plant) and that's just with the biochar made from Melbourne's landfill waste. Mookie's off-target. ============================================== I understand some people need small ideas. *Maybe some personal environment causes that. *But size can have useful consequences, not to say Mookie proposes a whole new topic area for space opera. *For my part, the more I think on these very large machines, the better I feel about it. *At the least, it's a remedy for the inner vacuum I've been feeling since Apollo was killed to free up a little money for the Vietnam war. A booster so large its liftoff has seismic consequences. Wonderful! *How close to this thing lifting off could you be and survive to tell of it? **That* is where I'd like to watch it from. A good thing about so much hydrogen and oxygen is, it burns without creating pollution. *(But I think the launch site might be kind of foggy for a day or two.) The problems I see are, 1) where does the energy come from that makes all that fuel? *And, 2) how do you store that much cryogenics stuff? I can see a rapid evolution of high-speed pump tech in this large-booster technology. I like big ideas, but few so big are realistic. *This one has made my day. Titeotwawki -- mha *[sci.space.policy 2008 Aug 08]- Hide quoted text - - Show quoted text - The vibrations of the 1.5 milion lbf M1 rocket engine were far less than the F1 engine - because hydrogen has different combustion characteristics relative to kerosene. Also advanced computer modelling available today, with modern materials, mean that these 100 million lb thrust engines will not be 60x noisier - though they will be noisier. I have thought this through pretty much - I have even met with government officials in Brazil, Gabon and Indonesia about it. I have even visited the islands and inland sites that I intend to use. (see my reply to Alan nearby) A set of 3 launch centers means that the 'bounce back' maneuver I've described elsewhere, will be obsolete by the time all the launch centers are fully functional - that is a booster will fly 1/3 the way around the world - and re-enter downrange. There a rocket base will refurbish and reuse the booster again - and it will be reocvered 1/3 the way around the world. Arriving after the second launch at its starting point. 'working' its way around the world. That's most efficient. 120 ships of tihs size, operating out of 3 fields, provide 1 launch to orbit every 8 hours - and provide a natural duty cycle to the 30,000 people involved - and puts up 30,000 tons per day - beyond LEO - 150,000 tons per day TO LEO. This is likely to take 15 years to 20 years to get started, and 20 to 30 years to complete the fleet build out. Today we need 17TW of power to run our economy. Growing at 7% per year means that need doubles every 10.7 years. We need 85 of the 10,000 ton satellites on GEO to meet TODAY's needs. In 20 years - we'll need 340 satellites - that's when we start - if we are to support continuous rapid pollution free growth. In 30 years we'll need 680 satellites. In 40 years, 1,400 satellites. This is for terrestrial use. The 210,000 sq miles oflands from a handful of today's large surface mine operators located in sunny regions - provide the receivers and basic infrastructure. Developoing this develops revenue streams and energy from terrestrial solar, and funds the development of the space leg. Once we get our economy back on track, - we'll find there are shortages in other things than energy. Raw materials. This will require a stream of materials harvested from the asteroid belt - using laser rockets powered by solar energy. This kicks demand up a notch - and begins to decouple power sat from energy needs, and starts involving it in material needs as well. This kicks demand up multiplying it - requiring the large rocket fleet within 30 years or so - when we fully populate GEO with power sats - we will have to adapt the laser targets at the focal point of each concentrator - to operate as free flying satellites - orbiting around the sun inside the orbit of mercury. Just as the terrestrial solar panel arrays were adapted to become powerful and efficient recievers of power from space, so too will the GEO based satellite fleet be adapted to reform powerful laser beams generated near the sun - this provides an additional factor of 100x to the powersat fleet's output - which allows it to easily handle all our material and factory needs as they develop on orbit. In sunsync polar orbit down around 1,100 km above Earth - a ring of rich asteroidal fragments, act as shepherd moons to a growing collection oflarge pressure vessels built on orbit. These start out as factories and smelting plants - but develop into farming satellites, forestry satellites,- built largely on orbit -and operated by telerobotic links from the ground - via satellite lbroadband. Products food, wood and paper, rain down in response to demand. Large pressure vessels are built and folded for entry into the Earth's atmosphere. There they deploy as they fall, creating floating cloud nine cities - that are powered by space laser beams, and fly through the skies of Earth as hot air dirigibles - carrying cities of 50,000 to 150,000 each. 30,000 of these citeis are eventually built and deployed, and provide an important stepping stone for the betterment of the poorest 1/3 of the human population. Eventualy the pressure vessels are built as private space homes robotically by the billions - and people by the billions will arrive in personal laser powered spacecraft to live and work on orbit. Laser and nuclear powered rockets will be purchased by many to move their space homes across the solar system. Laser light sails of tremendous capacity will be attached to space homes to move them beyond the solar system to the nearby stars beyond. This is our future. I am working on it today. I will be done within 80 years. I fully intend to be here then - haha- longevity research is advancing rapidly! - even so, human numbers will peak late 21st century and fall gradually thereafter. http://en.wikipedia.org/wiki/Aubrey_de_Grey |
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Super-heavy lift reusable launcher
Alan Erskine wrote: wrote in message ... Imagine a hydrogen oxygen rocket engine with an exit nozzle diameter of 17 meters in diameter, 36 meters long and produces a thrust of 53,300 tonnes with a specific impulse of 450 seconds. Not even if I were using drugs would I be able to imagine something so ridiculous as this. At least Sea Dragon got into that engine size category: http://www.astronautix.com/lvs/searagon.htm Pat |
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Super-heavy lift reusable launcher
On Aug 9, 12:03*pm, Ian Parker wrote:
On 9 Aug, 12:33, wrote: You are assuming that heavy lift is need for SSP. In fact what you require is the phase locking of small (a few Kw) units. Not when you look at lowest system cost. * There are cost differences when scale changes. * While it is feasible to build on the scale you speak of, it is not AS cost effective. * Demonstration projects using subscale systems - will certainly be built as you suggest. I am not talking about a sub scale system. I know. Phase linking produces a full size system. Yes. The question then is, what is the optimal size per module? There is one other point too. The system must be engineered to fail soft. Yes. This means that we need to divide up both solar power and computer power. You understand about phase linking. Do you understand conjugate wave formation and wave mixing? Nonlinear optics? In my system a pilot beam arrives from a receiver demanding power. That beam arrives at the laser window and creates a nonlinear optical effect. This mixes with the power laser beam and a portion of it is directed precisely along matched to the conjugate of the phase of the incoming beam. This means its phase locked to the weaker pilot beam, but travelling in the opposite direction. So, even if the pilot beam is distorted - the power beam is predistorted at its source, to arrive at the receiver - undistorted. If the pilot beam is interrupted for any reason, the power beam is cut off. If the pilot beam moves, the power beam follows. Please note there is no electronic computing or software involved at this point. Its all a matter of optics. So, given this system, what we're really talking about is the optimal window size to fabricate and launch using current technology. The Internet is composed of a lot of small units. Yes, so is the nonlinear window that works with the nonlinear reflector within the power laser's fabry-perot cell to generate powerful and controlled conjugate beams in response to weak pilot beams. The Internet has never failed even if individual units have. Same here- except on the atomic level. Light impacts the medium by changing its refractive index. The changing refractive index changes the path of light. These two operate together - along with the lasing cavity optics and the receiver optics - to create a fail safe system. The optimal size for a transportation system is far from being clear cut. Until you design a representative system - such as the one I've described. Weight goes up as L^3 whereas strength goes up only as L^2. Large units go better through the lower atmosphere, bur small units reenter better. This is one of many factors. The ability to fold thin films factors into this. I think we need to concentrate on $/Kg at LEO and on building an ion drive from LEO to GEO. Plus of course material from space. Yes. When you do that you find - what every other rocket scientist has found since the beginning of rocket science; 1) make the launch system reusable 2) increase the flight rate 3) increase the vehicle size That's why the Army, then the Air Force, then NASA, were building 1.5 million pound thrust engines on test stands back in 1959. The F1 and the M1. NASA inherited this work, and built the Saturn V around it. They were originally validating the scalaing laws for rocket engines - to see where they might go in the future. Those early studies suggest 100 million pound thrust engines are nearly optimal for interplanetary space operations done on a large scale. The size I propose here is nearly optimal to transition from chemical launcher, to chemical/laser launcher, Yes. I spoke with a few people about Laser Sustain Detonation launchers a few decades ago - and others about rail gun launchers. It makes an interesting system. On one end you have systems that are the size of dust motes - smart smoke one researcher called them. On the otheryou have systems that are the size of planets - these are the optical systems proposed by Bob Forward to beam energy to interstellar vehicles tens of light years away. Now, what's optimal depends on the details of how you do things. In any system that's never been done there are open issues - and estimates of the level of work required to resolve them - and the probability of success. Smart smoke level systems - the size of ICs or smaller - have distinct problems in maintaining phase lock across large populations - they're likely solvable but they're not resolved. They're a barrier to getting the job done. But, if you can build them, and operate them efficiently - yeah - you can use steam cannons, rail guns or laser launch capacity to fire them off like machine gun bullets into orbit. Are they the lowest cost way to go? Well, you can do it more cheaply than rockets today - AT A CERTAIN SCALE - WHEN THE PROBLEMS ARE RESOLVED. Until then, they're fantasy. But after - they're competitive in certain conditions. I can imagine a family having a packaged smart smoke dispenser aboard their space station that they land on a new world and deploy it. There are even designs I've studied that involve tiny wing shaped solar panels forming rotors - and two counter-rotating-rotors produce lift. Since the weight scales as the cube of dimension and the collector area scales as the square of dimension - smaller systems tend to have higher power to weight. So something the size of bumblebees can fly freely through the air and hav spare power to beam to a central collector. They all fly back to power center at the end of the day, to resume flight in the morning. You can even dispense with the MEMs based lasers and replace them with MEMS or nanoscale chemical processing centers, so the free flying solar aircraft accumulate fuel during daylight hours and dump it in a hopper at sunset. These are all possible, but they all have open issues that need to be resolved in order to be practical. The non-recurring level of effort impacts their value today. Iam certain given their advantages, they will one day be an important aspect to a solar power economy, but they will not lead the way, or be central on Earth - though they may be very important on the development of Mars or the Moon - or free flying colonies - in the future. Alright, now, we look at minature stuff - the size of ICs to Coffee Cups or bread baskets. These things have a different launch cost - and are most easily adapted to today's rockets. Especially using MIRV type technology - a nice little bus to hold all the pieces in place during ascent. This is one of the most costlyways to go. Now, as you get larger, something the size of automobiles or bigger - you can't use today's launchers easily, so you've got to start thinking about BIG launchers. The bigger you go, the problems of the smart smoke phase control go away. Lots of problems that the smaller systems go away - to be replaced by the bigger systems. Here,you have large collector areas, but in order to reduce costs, you have thin films - and fold those filmsinto compact forms the size required. When you start looking at chemical rockets - the kind we can build today - and start asking questions about what's the optimal size - then you are led inevitably to building bigger ships. Why do you think there is a push to build bigger sea going vessels? bigger airplanes? The efficiencies of scale. That's why you have 400,000 ton tanker ships that are nearly half a kilometer long plying the seas. That is also why the cheapest way to loft things off-world will be big ass rockets. Now there will be rail guns and laser launchers firing pellets into space at a rapid rate - just like there are pipelines and slurry lines - next to highways - but of all the things we have to build - we have to ask, what do we build first to get the biggest bang for the buck, and establish a dominant market position? The answer is, 1.5 million ton launchers lofting 10,000 tons ot GEO which is sufficient to loft a 200 GW powersat. and deep space laser probes, and laser recovery of asteroidal feedstock. haha.. *even at 200 GW per satellite - which is broken down using conjugate optics into many many beams some as small as 10 kW - you still have to combine 100s of satellites to do heavy lifting with laser energy - so 200 GW satellite size WILL also operate in phase locked mode - sharing a common pilot beam from a common receiver to usefully combine energies to do heavy lifting. As I said $/Kg not Kg at one go. Right. And $/kg is the driving factor. Similarly its $/kg not $ per launch. You need to ask the cost of the TOTAL weight. Yes. Can the weight be reduced by contributions from space? That cannot be done until an infrastructure is established and the weight of that infrastructure is known - I am not convinced you need more than 1000Kg at one go. Why? I agree with that, and I have solid scaling calcualtions to prove it. But what convinced you? You seem to be unaware of these sorts of things, so I'm curious. What's interesting is if you look at the consumption curve of each person throughout the day and by season at each latititude in an industrial society, and then you shift that curve by longitude and latitutde for each person - and then sumall the component curves - to get a global energy demand curve - you end up with something like 210 TW average power - which peaks at over 300 TW and drops to less than 100 TW - throughout the day. * * This means there will be 1,500 satellites of this size!! *So, they'll certainly operate in a variety of modes - including combining their outputs for space workmostly. Harvesting asteroids, sending out space probes, sending out interstellar probes, and so forth. If you choose a laser you can in fact supplement terrestrial photovoltaics from space. Yes, if you can accurately beam laser energy to the photovoltaics without loss. or with minimal loss. The pilot beam/power beam trick achieves this - but there is an optimal area for that as well - with today's optics. With tomorrows optics assuming certain advances - receivers will get smaller, intensities higher - optimal window sizes will fall - direct beaming to end users will be possible. All these things will happen - but not at first. This is quite interestin. I think you wil find that peak demand tends to be daylight hours. yes - for each latitude. What time of day is it where you live when the entire earth's power demand is lowest? When it is highest? There is such a time for each of us. Do you know what it is? That's what I'm talking about. Space would be very useful in the early evening. Laser energy generated anywhere in GEO can find its way to any point on Earth when needed. When its early evening in Hawaii, its early morning in India, and midnight in New York, and Noon in Sydney. What I'm talking about is the total demand for the entire Earth and how that varies. This is a function of distribution of population across the Earth. This means that there are certain times of the day that you'll have the 33 TW available for launch for 10 minutes or so at a time. *You'll be limited to launching fewer than 6 vehicles per day - once your system is fully use and integrated into the world's economy. Ultimately - 100 or so of the 200 GW satellites will be permanently dedicate to supporting space operations.- Hide quoted text - * - Ian Parker I think we're talking past each other in many ways. I have looked at small systems and once certain open issues are resolved they have great potential. ITs not something we can do easily today. Larger satellites built around inflatable optics - are far easier and cheaper to do - and have the least time to revenue and the lowest cost ot revenue, while ;providing very little room for competitors to do a technological end run around you while building a powerful barrier to entry in a variety of ways. |
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Super-heavy lift reusable launcher
The 37 meter diameter torus at the base of the payload shroud might
also carry up to 200 tourists who would pay to ride aboard the ship as it deployed the power satellite. They might also go on a space walk. Also a portion of the 90 teleoperated robots would deploy on the powersat to provide continuing maintenance capability from the ground. |
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Super-heavy lift reusable launcher
I got 1000Kg basically by balancing probable lift capabilities. In
fact theoretically you need a lot less but 1000Kg is a fairly easy figure to handle both from the balacing of lift and number of elements. Phase conjugation. If wave equation is exp(ikx) It follows that if we emit exp(-ikx) we will get reinforcement at the source. Hence we have to take the complex conjugate. In the case of microwaves this is fairly simple. With light you STILL need sone element of computation. You need to send a signal from some point to your individual lasers and then compute the phase angle knowing the phase angle introduced by your beat source. Also you need to do a phase calculation for EACH laser diode. An individual diode will only emit a few watts. Basically the size and angular spread of an individual diode will depend on the total area covered. This could be the size of a hemisphere of Earth giving quite a large angle. I think it iis important for everone to appreciate though that this is very much a soft failing system, and that this system is intrinsically very safe. Thinking about it I like it as there is NEVER a danger of out of control beams. Rand is perfectly correct in supposing that you don't need to be at GEO. MEO is as good. LEO is not really feasible as you can't operate at night. If you rely on conjugation you can have positions constantly changing. - Ian Parker |
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Super-heavy lift reusable launcher
Ian Parker wrote:
: :You are assuming that heavy lift is need for SSP. In fact what you :require is the phase locking of small (a few Kw) units. : That may be what YOU require, but is anyone proposing building one that way? Why do I doubt it? -- "Ignorance is preferable to error, and he is less remote from the truth who believes nothing than he who believes what is wrong." -- Thomas Jefferson |
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