A Tripolation Posted January 14, 2011 Share Posted January 14, 2011 That "at this moment" is the key concept. None of the technologies proposed in this thread is ready for prime time. Many never will be; that's just the nature of the research game. The hope is that at least one of them will be sometime in the future. Indeed. I meant to italicize "at this moment" but for some reason did it to "implausible" instead. It's fixed now. My mistake. Link to comment Share on other sites More sharing options...
Moontanman Posted January 14, 2011 Share Posted January 14, 2011 (edited) D.H. is correct, there is a wide gulf between what we can do today and what we might be able to do today, i didn't mean to imply the Nuclear Light Bulb Rocket could be made easily, next week or next year but as things stand now we will never even try, I wanted to point out that going into space in a big way did not require Star Trek type technology or technologies beyond our current ability or understanding. The NLBR is a good example of technology that could give us a huge leg up into the Solar System and still be with in the bounds of what we can do with out defying the laws of nature or even really stretching our technology. I do not think chemical rockets will ever be enough to do what we need to do much less what we want to do. I do indeed have great respect for NASA, they do some astounding things with very little money, it's real science and D.H was correct in pointing out the reality of the situation to us. I make no apologies for being pro nuclear, in the long run nuclear power is the only way we will be able to capitalize on the resources of the solar system. personally i think nuclear power s the key to our continued civilization on this one small planet, at least if we continue to insist on uncontrolled growth. I honestly think that our continued fear and loathing of anything nuclear is either something we will get over or we will die clinging to that out modded and totally unreasonable fear. It bothers me quite a bit there is no trace of Anthony Tate that would suggest he has any real connection with NLBR, it also bothers me quite a bit that there is nothing to support at least the testing of gaseous core nuclear reactors. It's quite possible I've been punked, it happens, but I remain staunchly pro-nuclear power, both on the Earth and in space. it is off topic here but i think nuclear power is completely supportable as a power source for our civilization. Edited January 14, 2011 by Moontanman 1 Link to comment Share on other sites More sharing options...
InigoMontoya Posted January 15, 2011 Share Posted January 15, 2011 (edited) That is why NASA and agency are looking into other propulsion systems not say mainstream scientist are starting to look into other propulsion systems. But this poster DH is saying everyone at NASA and other agency not say airforce and mainstream scientist are all crack pot ideas and chemical rockets are the only way too go It's not just DH... I'm on his team. All that other stuff - with the possible exception of fission (which is politically unviable) - ARE crackpot ideas. I believe I stated as such. I believe we both stated that NASA and other agencies DO fund crackpot ideas for the unlikely direct payoff or more likely spin-off technology. ,and he saying get of scfi and I'm sure he is a lobbyist that wants to do away of human space flight and go to space probes ,robots and hubble only. Or he's an Aerospace Engineer who tries to stay grounded in reality and doesn't let his imagination taint his analysis of the situation. Also, some of us *do* represent government agencies as our day job. That means lobbying would be illegal. So if Queen Isabella and Spain had been researching better birch bark canoes Columbus should never have been financed? Actually, that's a great point regarding crackpot ideas. Spain funded Columbus at a very low level. They gave him three old, beat to shite ships that were most likely not going to be around too much longer. They gave him spare parts that were destined for the trash... Just like the laser propulsion guy in the video posted earlier. He's got an old laser from the SDI program; spare parts that were destined for the trash. Two crackpot ideas funded at a very low level. One had an enormous payoff. The other not so much (at least, not yet). Could the current guy get the last laugh? Absolutely, and that's why crackpots still get funded. As a propulsion geek I hope he does.... But I'd have to be offered some massive odds to bet on him. Edited January 15, 2011 by InigoMontoya Link to comment Share on other sites More sharing options...
wright496 Posted January 18, 2011 Share Posted January 18, 2011 (edited) We were making excellent progress in nuclear propulsion, and politics was really the only thing that brought that to a halt. NERVA met or exceeded all expectations and NASA had big plans for it. What really irks me is that people are so lackadaisical in their attitudes towards things like space exploration, but billions are thrown seemingly indiscriminately at the military. Scientists and engineers from pretty much any field that you can think of are finding creative military applications for their work w/ fecundity because it's an easy path to funding(if there really is such a thing). I would like to try offering those kinds of incentives for contributing to the space program. Space exploration is a matter of great importance and I don't know why so many people seem to have a hard time grasping this. Overpopulation is ultimately one of the greatest problems facing humanity. Everyone thinks it's their right to have kids, but honestly, without expanding away from Earth, this is clearly not an option. As draconian as it sounds the only real choice would be to keep people from reproducing. Not enough people will make that choice on their own. And then there's the threat of an asteroid or what have you. The probability that something like this will threaten Earth is for our purposes...inevitable. It might not happen real soon, but it very likely will eventually. I'm sorry to veer off into politics and policy when this thread is primarily about the engineering aspects, but the point I'm trying to make is that the things I'm talking about are the biggest obstacles to contend with in this endeavor and NOT the technical feasibility. I really felt the need to establish that. I think things will actually go much better now that the private sector is being allowed to pursue this. Edited January 18, 2011 by wright496 Link to comment Share on other sites More sharing options...
D H Posted January 18, 2011 Share Posted January 18, 2011 We were making excellent progress in nuclear propulsion, and politics was really the only thing that brought that to a halt. NERVA met or exceeded all expectations and NASA had big plans for it. The Apollo program was a large drain on the federal government. The nuclear space concepts such as NERVA would have made the huge expenditures on the Apollo program permanent. Congress and the President did not want NASA to continue at those high level of expenditures forever. They had other things to fund: the Vietnam War, the Great Society programs, etc. Apollo, along with everything that went with it, was political toast once the primary mission was accomplished. Space exploration is a matter of great importance and I don't know why so many people seem to have a hard time grasping this. Overpopulation is ultimately one of the greatest problems facing humanity. Everyone thinks it's their right to have kids, but honestly, without expanding away from Earth, this is clearly not an option. As draconian as it sounds the only real choice would be to keep people from reproducing. Not enough people will make that choice on their own. Space exploration is not going to solve the population growth problem. The ability to put millions of people per year into space is a long ways into the future. The current population growth rate is about 75 million people per year. The growth rate is expected to decline but still be positive, and by a huge amount, for a long time. By the time space exploration becomes available to the masses we will either have solved the population growth problem on our own or the problem will overwhelm us (and there will be no space program anywhere). And then there's the threat of an asteroid or what have you. The probability that something like this will threaten Earth is for our purposes...inevitable. It might not happen real soon, but it very likely will eventually. The proper recourse here is to do something positive about the supposed problem, not to flee it. We should be looking for those killer asteroids (we are) and if we see one, do something about it. The killer asteroids are big, fairly easy to see. Smaller ones are harder to see but are not a threat to civilization as we know it. I've never been fond of the space exploration as a population relief mechanism or space exploration as a disaster avoidance mechanism arguments. One reason for space exploration is that we are curious apes. We explore. Humans and our ancestors have been explorers for millions of years. Another reason is that we are greedy little apes. Space is full of exploitable resources, but we do have to drastically reduce the cost of access to make exploiting those resources make sense economically. I'm sorry to veer off into politics and policy when this thread is primarily about the engineering aspects, but the point I'm trying to make is that the things I'm talking about are the biggest obstacles to contend with in this endeavor and NOT the technical feasibility. I really felt the need to establish that. Since space exploration is largely government funded, it is hard not to veer off into politics. We talk about science and engineering concepts here because most of us don't grok politics. Politics is not rocket science. That's why rocket scientists do so lousy in understanding politics. I think things will actually go much better now that the private sector is being allowed to pursue this. The private sector has been allowed to pursue this for a long time. A good fraction of the satellites in geosynchronous orbit are privately-owned (non governmental) satellites and were launched on privately-owned launch vehicles. What is new is that companies such as Virgin Galactic / Scaled Composites are looking to bring paying passengers into space (but for the most part not into orbit). Another new development is embodied by SpaceX. He is bringing the entrepreneurial spirit into the launch business. The companies that currently do do private launches once had that entrepreneurial spirit, but they appear to have lost it long ago from too much feeding at the government trough. Link to comment Share on other sites More sharing options...
Moontanman Posted January 18, 2011 Share Posted January 18, 2011 I have to apologize to D.H., I have researched Anthony Tate as throughly as I can and I cannot find any trace of him or any reason to believe he has anything to do with gaseous core reactors. Evidently I was taken to the cleaners on that one... Link to comment Share on other sites More sharing options...
D H Posted January 18, 2011 Share Posted January 18, 2011 There has been theoretical work on gas core nuclear reactors, and they might will be the next big future. This is just one of a plethora of very low TRL ideas that should be funded (albeit on a very low level). Nobody has the crystal ball that will let us look fifty years or more into the future to see the very few of that plethora of ideas that truly are the next big future. 1 Link to comment Share on other sites More sharing options...
InigoMontoya Posted January 19, 2011 Share Posted January 19, 2011 (edited) Space exploration is a matter of great importance and I don't know why so many people seem to have a hard time grasping this. Overpopulation is ultimately one of the greatest problems facing humanity. Everyone thinks it's their right to have kids, but honestly, without expanding away from Earth, this is clearly not an option. DH already pointed it out, but I think this bit of common mythology needs bludgeoning every time it raises it's head. SPACE EXPLORATION WILL NEVER HELP REDUCE GLOBAL POPULATION. NEVER. As was stated, you need to move 75 *million* people a year just to keep up. Even if Mars was a veritable Garden of Eden (which it obviously is not) you just couldn't do it. Right now the cost of lifting a pound to escape velocity is something like $4,000. Let's suppose somebody just goes crazy and finds a way to reduce that cost by a factor of 20. Cost to escape velocity is now $200 per pound. Wow, that's pretty damned good! Average person weighs 150 pounds? Hey, you can get a ticket for $30,000. But don't forget, it takes 6 months to get to Mars. How much food do you need to eat? I'll assume you're recycling the water, but you still need to bring on board 6 months worth of dehydrated food. I'll be nice and call that another 150 pounds. Ooops, we're up to $60,000 a seat.... And that assumes you leave *everything* behind and that somehow you'll be living in space and entering Mar's atmosphere naked (I've included no allowance for your actual space ship!). Sure, some people could and would pay it out of pocket, but the numbers for that are small indeed. It would have to be a government-funded program for the most part. Now, assuming that each country is supposed to send a proportionate number of people per year, that means the US would have to send on the order of 3 *million* people a year. At a cost of $60,000 *each*. Total cost just for the US portion? $180 BILLION. Per year! On top of everything else. Just to tread water for global population. And even if the US can afford it.... What about all those parts of the world that couldn't? And remember, those numbers are fantastically optimistic. The reality would be much, much worse. You'd probably need more like 5,000 pounds of lift capability per person (not 300 pounds) and let's not forget that the factor of 20 improvement is completely unrealistic. As draconian as it sounds the only real choice would be to keep people from reproducing. Not enough people will make that choice on their own. Actually, there's nothing draconian about it. I've applauded China's efforts for years. There are only four *realistic* options for controlling population: 1) Birth control (either voluntary or forced). 2) Disease. 3) Famine. 4) War. With options like that, even forced birth control is pretty benign. Edited January 19, 2011 by InigoMontoya Link to comment Share on other sites More sharing options...
D H Posted January 19, 2011 Share Posted January 19, 2011 Voluntary birth control is working quite well in the developed nations. Maybe too well; population growth in western Europe is negative. This illustrates another reason why space technology will not help solve the population growth problem: The population growth problem is a problem in countries that essentially have no technology, let alone no space technology. Link to comment Share on other sites More sharing options...
nec209 Posted February 1, 2011 Author Share Posted February 1, 2011 (edited) Like the other poster here say it not going happen it is scfi. I have done some reading and writting my own report on this . This was I wrote to other message boards.It sad but this is reality you would get nobel prize in physics if you even come up with theory on hard to bring the space cost down than alone test and build it !!! In other words no one has theory that alone of putting theory on black board in to the real world of testing and building it. It has come up here and on other message boards on warp drive ,space mining ,space colony and starships .Also on TV show Sci Fi Science: Physics of the Impossible and the book physics of the impossible by Michio Kaku . Here is what I wrote . Yes I'm fan fan of the TV show Sci Fi Science: Physics of the Impossible and the book physics of the impossible by Michio Kaku !! I think there was some bad flaws on his part has it is premature to talk about starship ,warp-drive ,space mining and space colony to the number one problem is to bring the space cost down to open up acess to space. Has of now only 3 countries can go in space no more than 5 times a year that cost money like a leaky faucet .Not to say lobbyist hard at work to do away of man space-flight and go with space probes. The reason the space program has not done much in past 50 years is cost .And space mining or 5% or 10% of the people on earth going into space is prohibited expensive. The number one problem is to bring the space cost down to open up acess to space. Than we can work on harder stuff like starship ,warp-drive ,space mining and space colony that is much harder and will take longer.Why because as of now not even less than 1% of people will have money to go into space and lobbyist hard at work.When the space cost goes down more countries can be putting people into space every week or more than every two months. I feel he did not say much about the space program and discusess enough about the propulsion system. It is to bad but Ion propulsion or plasma propulsion does not have enough thrust to lift any thing from earth.And laser propulsion and microwave propulsion cannot work in space has it is energy and not mass .Not to say it needs gigawatt power and that much power the craft would be power station and inpossible to make floating power station.Well fusion propulsion no point talking about that to we get working fusion .And anti-matter way too costly and cannot be stored or used as a fuel .It take long time if it is even inpossible to make anti-matter cheap and find out a way to store it and use it has a fuel. And fission propulsion may work but people fear fission .In the end we only have chemical propulsion to get in space and it is coming to brick wall with being more fuel efficient and lower cost .In the future when the engineering problems are solved if they are solved than may be they can look into ant-matter and fusion propulsion . Other than that it is hope fringe propulsion one of them to out to be real like negetive energy or negetive matter and no one has made it or seen it in world , so may be one day we may make it !! Now levitation or anti-gravity no one has made it or seen this in world so may be it is real but no one has discovered it yet.And megnetic propulsion well we do not know how to make a monopole. If not and we find no other propulsion than space mining ,space colony ,warp drive and star ship is very much going to be scfi. ============== To bad but in end we are long long long long long way away of warp drive ,space mining ,space colony and starships if impossible . Edited February 1, 2011 by nec209 Link to comment Share on other sites More sharing options...
JohnB Posted February 2, 2011 Share Posted February 2, 2011 DH, since the big picture is your field, could you please answer a couple of questions that have bugged me for some time? 1. WRT orbital launches, why do we still go straight up? I always thought the old George Pal idea of a horizontal launch and a ski jump was rather good. That way you are using the fuel on the main stage to gain speed rather than using it to lift fuel. Is it simply that a bird strike at 6,000 mph is very ungood? There is still talk about the flyable scram jet booster planes, but they will be big birds to carry a shuttle sized load on their backs. 2. Concerning the ISS design. It seems a rather pointless design. (As in it is an end in itself and not particularly expandable.) SF has put forward the idea for decades that the logical way to build a station is to launch a "Hub" section that the ascent stages of later rockets dock with to become spokes in a wheel. As you need more space you then add another "Hub" and more spokes, or add modules that extend the existing spokes. Eventually you send up the plating and sheet the whole thing in and rebuild the interior into a big tin can. Basically it is a design that can evolve as needs be. Is the problem that space is primarily government funded and politicians can't handle the concept of planning further than the next election? And I just have to add; no, gaseous core nuclear reactors have not been made. All that has been done is paper studies and computer models. Perhaps the Aerospace industry needs to borrow the ones the climate modellers use? Apparently theirs are just as good as reality. Think of all the money you could save on testing equipment, if the models agree the ship will fly, then it will fly. The models say so. Link to comment Share on other sites More sharing options...
Mr Skeptic Posted February 2, 2011 Share Posted February 2, 2011 1. WRT orbital launches, why do we still go straight up? I always thought the old George Pal idea of a horizontal launch and a ski jump was rather good. That way you are using the fuel on the main stage to gain speed rather than using it to lift fuel. Is it simply that a bird strike at 6,000 mph is very ungood? There is still talk about the flyable scram jet booster planes, but they will be big birds to carry a shuttle sized load on their backs. I'm pretty sure that the only reason to go horizontal is to make the most of wings (ie using the air as extra mass for propulsion). Given the wings on rockets are quite insignificant it's probably better off and safer to just go straight up most of the time. Perhaps the Aerospace industry needs to borrow the ones the climate modellers use? Apparently theirs are just as good as reality. Think of all the money you could save on testing equipment, if the models agree the ship will fly, then it will fly. The models say so. Computer models are only as accurate as they are made, and can ignore aspects of reality if the moddeler feels like it or doesn't know any better. For example the computer model might ignore the wear and tear aspects, or might ignore the problem that radiation can increase brittleness. The only way to know for sure if your model works is to compare it to reality, like is done with the climate modeling. Also consider that climate modeling is its own science and hardly anyone has expertise modeling gas core nuclear reactors. Link to comment Share on other sites More sharing options...
InigoMontoya Posted February 2, 2011 Share Posted February 2, 2011 1. WRT orbital launches, why do we still go straight up? I always thought the old George Pal idea of a horizontal launch and a ski jump was rather good. That way you are using the fuel on the main stage to gain speed rather than using it to lift fuel. Is it simply that a bird strike at 6,000 mph is very ungood? There is still talk about the flyable scram jet booster planes, but they will be big birds to carry a shuttle sized load on their backs. 1 - Going 6,000 mph through sea level air doesn't require a bird strike... Just the air itself is going to hit you like a farking brick wall and turn your spaceship into a puddle of molten metal. UNLESS... You have heat shielding that is insanely thick and heavy. But now all your payload has turned into heat shield. Remind me again what the point of this was? 2 - The logistics of maintaining a loooooooong track that can handle heavy objects moving at 6,000 mph are not to be ignored. 3 - That ski jump at the end. Just how many Gs did you plan on pulling? 'Cause if it's anything other than an insane amount, you're going to lose all those benefits of a horizontal launch by bleeding energy in that thick atmosphere. And if it is an insane number of Gs, well now you're vehicle needs to be even heavier since you have extreme Gs in a non-axial direction. 4 - Yeah, bird strikes would suck. 2. Concerning the ISS design. It seems a rather pointless design. (As in it is an end in itself and not particularly expandable.) SF has put forward the idea for decades that the logical way to build a station is to launch a "Hub" section that the ascent stages of later rockets dock with to become spokes in a wheel. As you need more space you then add another "Hub" and more spokes, or add modules that extend the existing spokes. Eventually you send up the plating and sheet the whole thing in and rebuild the interior into a big tin can. Basically it is a design that can evolve as needs be. Is the problem that space is primarily government funded and politicians can't handle the concept of planning further than the next election? Even neglecting the costs... Have you ever tried docking a space ship to a spinning hub? How do you add a single "spoke" (aka, space ship) without throwing the whole thing off balance? And if the thing is off balance, how in the hell do you dock to begin with? It *sounds* like a good idea but the realities of actually assembling such a beast are miles more difficult than the realities of the ISS... And remember that just docking with the ISS isn't seen as a trivial task. Doable? Sure, but not trivial. Link to comment Share on other sites More sharing options...
JohnB Posted February 2, 2011 Share Posted February 2, 2011 Mr Skeptic, my tongue was firmly in cheek for the last bit. However, if you believe a non linear chaotic system can be modelled with accuracy for a 100 year outlook, mere aeronautics should be a doddle. I wasn't thinking about wings at all, if anything they are superfluous. The shuttle uses quite a bit of power to lift its own mass against gravity as well as accelerating itself. Since the key to orbit is speed, why not lay the sucker down and go sideways? That way all the thrust translates into speed. Run it on a rail across flat land and then up the side of a mountain for the ski jump. The shuttle engines develop some 1.2 million pounds of thrust, much of which is used to counter the effect of gravity and lifting by brute force the mass of the fuel tank and spacecraft. The liftoff weight is 240,000 pounds so almost 1/4 of the trust is wasted lifting the craft. By going sideways that wasted thrust is converted directly into speed. this should mean a larger payload for the same fuel or less fuel required. AFAIK speed is the key, once something is travelling fast enough you would have to expend energy to stop it from going to orbit. The downside is that by going sideways you are travelling very fast at zero feet. A birdstrike at 6,000 mph would be a major problem. Link to comment Share on other sites More sharing options...
InigoMontoya Posted February 2, 2011 Share Posted February 2, 2011 I wasn't thinking about wings at all, if anything they are superfluous. The shuttle uses quite a bit of power to lift its own mass against gravity as well as accelerating itself. Since the key to orbit is speed, why not lay the sucker down and go sideways? That way all the thrust translates into speed. Run it on a rail across flat land and then up the side of a mountain for the ski jump. Have you ever *watched* a shuttle launch? Almost immediately they *do* lay that sucker over and start going for speed.... Just as soon as they're out of that pea soup we call the lower atmosphere. Link to comment Share on other sites More sharing options...
JohnB Posted February 2, 2011 Share Posted February 2, 2011 Inigo, we must have cross posted before. I did think that you might lose payload in armour, but I wasn't sure. So I asked. As to the "ski jump", I was thinking of a curve with a radius measured in miles that does little more than kick the craft up to a 40 degree angle. You perhaps misunderstood me about the station. I never said it was spinning. I simply meant something that is modular and expandable. Until you make something pretty big I don't see spin as a great idea anyway. Unless there is a fair diameter you would have to spin the thing too fast to get a meaningful gravity effect. Link to comment Share on other sites More sharing options...
Mr Skeptic Posted February 2, 2011 Share Posted February 2, 2011 Somehow I totally missed that you were suggesting a runway . It may be a good idea but you have to remember that the faster you go the longer the runway needs be for every second the craft is to spend on the runway. The craft will have to be strong enough to resist 1 g in another direction than just the engines, and more for the ski jump, which would add more structural weight for the ship and perhaps its cargo. The ski jump would have to be very tall considering the speed at which the craft would be going by then. All this translates to quite a bit of cost especially considering that we would be using it like 5 times per year. If you consider the possibility of sabotage, a giant runway is a huge security risk as well, and possibly a safety risk too. Ooh, and the runway also has to be able to survive being torched by shuttle exhaust, so asphalt is probably out of the question. Link to comment Share on other sites More sharing options...
D H Posted February 3, 2011 Share Posted February 3, 2011 1. WRT orbital launches, why do we still go straight up? I always thought the old George Pal idea of a horizontal launch and a ski jump was rather good. The ski jump idea is just silly. It is straight out of bad 1950s genre science fiction movies, which was George Pal's forte. We launch vertically because rockets are very strong longitudinally, rather weak in other directions. Making a rocket so it can withstand transverse stress and strain would require adding structural mass to the vehicle. A lightweight vehicle is what is needed to get a payload into space. Look at the video just provided by Mr. Skeptic. The Shuttle maintains its vertical launch altitude for a very short time. Shortly after the Shuttle safely clears the tower it initiates a "roll program". This is a simultaneous roll, pitch, and yaw maneuver. The vehicle is no longer oriented vertically at the end of this maneuver. It is instead on a gravity turn trajectory. One advantage of a vertical launch is that the launch vehicle gets above the thick part of the atmosphere in a very short time. Note that in the video provided by Mr. Skeptic, less than a couple of minutes after launch the Shuttle already has an altitude of 22 miles. It's also 18 miles downrange. At this point it's flight path angle is now closer to horizontal than vertical. While traditional rockets need to be launched vertically, proposed vehicles such as the might be launched horizontally. The reason would not be to make the profile as efficient as possible. Just as rockets are launched vertically because of structural and launch tower constraints, a rail-launched vehicle would be launched horizontally because of the use of a rail. A rail launch system has been proposed as the zeroth stage of a scramjet launch system. 2. Concerning the ISS design. It seems a rather pointless design. (As in it is an end in itself and not particularly expandable.) SF has put forward the idea for decades that the logical way to build a station is to launch a "Hub" section that the ascent stages of later rockets dock with to become spokes in a wheel. As you need more space you then add another "Hub" and more spokes, or add modules that extend the existing spokes. Eventually you send up the plating and sheet the whole thing in and rebuild the interior into a big tin can. Basically it is a design that can evolve as needs be. Is the problem that space is primarily government funded and politicians can't handle the concept of planning further than the next election? There is no reason for a vehicle to be particularly pretty in space. The ISS has been reconfigured multiple times. It's not particularly pretty, it's not all that sci-fi looking, but really, who cares? There are several problems with the ISS. One of the biggest is the 51.6 degree orbit it is in. That orbit a result of politics. Link to comment Share on other sites More sharing options...
JohnB Posted February 3, 2011 Share Posted February 3, 2011 We launch vertically because rockets are very strong longitudinally, rather weak in other directions. Making a rocket so it can withstand transverse stress and strain would require adding structural mass to the vehicle. A lightweight vehicle is what is needed to get a payload into space. Thanks DH, that simple paragraph explains all. The ISS doesn't need to look pretty or sci-fi, it needs to be efficient. I just think the open lattice type design, once past a certain size would be very inefficient. You would spend too much time travelling through sections to get to your destination. It also means that labs and berths become thoroughfares. Whereas the hub and spoke system means that you exit your current compartment into the hub and then immediately enter your destination compartment. I'm not talking about a 2001 style wheel here, just a hub section large enough to dock the spoke sections to. Such a design is modular and very expandable. I'm sure that there are extremely good reasons for the way it was built. I just don't see them. But then, I also don't have the required training either. I was hoping that like the first question, there is a simple answer. Link to comment Share on other sites More sharing options...
wright496 Posted February 7, 2011 Share Posted February 7, 2011 DH already pointed it out, but I think this bit of common mythology needs bludgeoning every time it raises it's head. SPACE EXPLORATION WILL NEVER HELP REDUCE GLOBAL POPULATION. NEVER. As was stated, you need to move 75 *million* people a year just to keep up. Even if Mars was a veritable Garden of Eden (which it obviously is not) you just couldn't do it. Right now the cost of lifting a pound to escape velocity is something like $4,000. Let's suppose somebody just goes crazy and finds a way to reduce that cost by a factor of 20. Cost to escape velocity is now $200 per pound. Wow, that's pretty damned good! Average person weighs 150 pounds? Hey, you can get a ticket for $30,000. But don't forget, it takes 6 months to get to Mars. How much food do you need to eat? I'll assume you're recycling the water, but you still need to bring on board 6 months worth of dehydrated food. I'll be nice and call that another 150 pounds. Ooops, we're up to $60,000 a seat.... And that assumes you leave *everything* behind and that somehow you'll be living in space and entering Mar's atmosphere naked (I've included no allowance for your actual space ship!). Sure, some people could and would pay it out of pocket, but the numbers for that are small indeed. It would have to be a government-funded program for the most part. Now, assuming that each country is supposed to send a proportionate number of people per year, that means the US would have to send on the order of 3 *million* people a year. At a cost of $60,000 *each*. Total cost just for the US portion? $180 BILLION. Per year! On top of everything else. Just to tread water for global population. And even if the US can afford it.... What about all those parts of the world that couldn't? And remember, those numbers are fantastically optimistic. The reality would be much, much worse. You'd probably need more like 5,000 pounds of lift capability per person (not 300 pounds) and let's not forget that the factor of 20 improvement is completely unrealistic. Actually, there's nothing draconian about it. I've applauded China's efforts for years. There are only four *realistic* options for controlling population: 1) Birth control (either voluntary or forced). 2) Disease. 3) Famine. 4) War. With options like that, even forced birth control is pretty benign. You guys misunderstood me. I don't think space exploration alone is the solution for overpopulation. But is there a good single solution? This is one of those problems that needs to be attacked from a variety of angles. In this context it could be useful for overpopulation. Link to comment Share on other sites More sharing options...
InigoMontoya Posted February 8, 2011 Share Posted February 8, 2011 You guys misunderstood me. I don't think space exploration alone is the solution for overpopulation. But is there a good single solution? This is one of those problems that needs to be attacked from a variety of angles. In this context it could be useful for overpopulation. No, you really don't get it. Space exploration is - and always will be - such a fringe activity that it will have less of an impact on global population than the weather does. One heat wave or cold snap in Europe is responsible for removing more people from Earth than the space program has in 50 years (even assuming that those who went up never came down). Simply making drinking and driving totally legal would do MUCH MUCH MUCH more to curb population growth. Space exploration and population control simply shouldn't be mentioned in the same sentence. Link to comment Share on other sites More sharing options...
zapatos Posted February 8, 2011 Share Posted February 8, 2011 DH already pointed it out, but I think this bit of common mythology needs bludgeoning every time it raises it's head. SPACE EXPLORATION WILL NEVER HELP REDUCE GLOBAL POPULATION. NEVER. I think that depends on how you look at it. It certainly seems likely that space exploration will not reduce the number of people on earth today, but it can have a big impact on the future population. Any child born somewhere other than earth means the population of earth will not be increased by that birth. So while the population of Africa has gone up substantially since the first people left that continent, its population is much lower than it would have been if all the people born somewhere other than Africa had instead contributed to the population of Africa. Similarly, if thousands of years from now humans are being born somewhere other than earth, I think it would be fair to say that space exploration contributed to a reduced population on earth. Link to comment Share on other sites More sharing options...
InigoMontoya Posted February 8, 2011 Share Posted February 8, 2011 I think that depends on how you look at it. It certainly seems likely that space exploration will not reduce the number of people on earth today, but it can have a big impact on the future population. By that definition, the game of Football is a great population control tool. I mean, after all, from time to time people do die playing it. And I think that along those same lines, sandpaper is a great way to carve a tunnel through 2 miles of solid granite. After all, it does remove rock. Link to comment Share on other sites More sharing options...
zapatos Posted February 8, 2011 Share Posted February 8, 2011 By that definition, the game of Football is a great population control tool. I mean, after all, from time to time people do die playing it. And I think that along those same lines, sandpaper is a great way to carve a tunnel through 2 miles of solid granite. After all, it does remove rock. Love the sarcasm. But you are the one who introduced the long time frame when you said "SPACE EXPLORATION WILL NEVER HELP REDUCE GLOBAL POPULATION. NEVER." Next time if you provide me with the time frame I'm allowed to consider I'll limit my comments accordingly. Link to comment Share on other sites More sharing options...
wright496 Posted February 9, 2011 Share Posted February 9, 2011 No, you really don't get it. Space exploration is - and always will be - such a fringe activity that it will have less of an impact on global population than the weather does. One heat wave or cold snap in Europe is responsible for removing more people from Earth than the space program has in 50 years (even assuming that those who went up never came down). Simply making drinking and driving totally legal would do MUCH MUCH MUCH more to curb population growth. Space exploration and population control simply shouldn't be mentioned in the same sentence. It's only a fringe activity because we keep neglecting it. One of the main points I'm trying to make is that it SHOULDN'T be such a low priority. You seem to be confusing this with some sort of inherent technical difficulty when in fact it's a matter of politics. And you still didn't answer my question as to what you would recommend. Yeah getting women educated and in the workforce is the best single thing we've got for this problem, but that's not enough either. Link to comment Share on other sites More sharing options...
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