Ye gods, not only did you not read the links, you didn't even read the original post. You use maglev rails, probably three of them, to push the vessel up out of the tower (its a tower, not a platform), powered by a nuclear reactor in the base. This system can indeed blast you to escape velocity in one shot, however you would be dead. So instead we go to the perfectly palatable low earth orbit, from whence you can go anywhere you like.
This was studied in regards to cannon launch - it does work, but is probably too complex to be comercially viable.
Every single time... please read the links, we are not talking about cannon launches here. We are talking about using the length of the tower to accelerate it.
The real killer in these types of designs is the accelarator - electromagnetics just don't work as well as most people think. High velocities are practically unatainable in reality.
Sorry, try again. Plenty of research shows that it can be done. Its just not financially worth it to put a maglev tunnell across the Atlantic ocean. Now 11km on the other hand is eminently feasable...:D
Space elevators have a low mass throughput rate and high maintainence costs
No, space elevators have no mass throughput rates and no maintenance costs, and thats because they don't exist and are unlkely to exist this century.
Sternfeld's analysis doesn't consider engineering at all, his constraints are based solely on the accelerations that human beings can whitstand.
Yes and you are still coming at it from the "cannon to escape velocity" angle. The power is provided throughout the length of the launch, not in one single jolt, and while you could reach escape velocity with it, anyone in the ship would be pink wallpaper. Useful for certain types of cargo, however. The idea is only to get to LEO.
Physics has a truth that even political ideology cannot deny.
I was always more of a technocracy with direct democracy via proportional representation kinda guy, myself.:D
And that's that. No matter from which height you launch, orbital velocity is at least several thousand meters per second and that must come from somewhere. Building a 11km high structure just to get rid of those 15% lost to atmospheric drag doesn't seem quite practical to me...
Okay sorry now, you've completely lost the plot here. They are talking about lifting a rocket to the top of a tower and launching it. I am talking about using the length of the tower to accelerate the vessel and compensate for lateral velocity with onboard fuel, a whole other fish. Much much less than would otherwise be needed, however, which means you have more space for other things.
The beauty of it all is that the space elevator seems to be almost within reach, we can build it in less time than it will take us to develop other alternative means for getting into orbit.
There are zero guarantees we can build it at all, or within the next century at any rate. Seems to be almost within reach is just not realisitic in this context. All of the components for the system I propose, however, exist already. Today. Here. Now.
If you accelerate something to escape velocity, it does exactly that: escapes the gravitational attraction of the Earth and never comes back, unless it's decelerated by some unspecified means. And escape velocity at 11km height means it will be burned to ashes very quickly, remember the Columbia. With our current technology level, building a ship that can fly at escape velocity at 11km height is much more difficult than building a space elevator.
Whoops yes sorry, thats what happens when you repost something after several discussion on it. The escape velocity part shouldn't be there, since to reach escape velocity you would need many more gees than the human body could take for too long. And in any case, the high speeds are reached at the point where the ship enters the atmosphere above the troposphere (another editing error, hey this is slashdot, what can you do), so the effects of the atmosphere are greatly reduced. I should really make a website about this.
OTOH, if you want to put something in orbit around the Earth, then you should give it orbital velocity, which means it should have a very high tangential velocity around the Earth. You cannot do that with a vertical tower, unless that tower reaches the synchronous orbit altitude of 36000km, which is the whole idea of a space elevator. Remember, velocity is a vector. It has both magnitude and direction. If you want to reach orbit, it's useless to throw something straight up with a high speed, because it will fall straight down.
Yes, thats angular momentum there, the craft would probably need some kind of power to adjust for that. Far, far less than a standard earth based launch however, which again leads to greatly increased room for other cargo and reduces the cost to orbit.
Well, you may say, let's make the top of the tower curved, so the ship will be accelerated tangentially.
No no, you can't do that. the only place you can have curvature is at the start of the acceleration. Trying to curve the trajectory of a significant mass at those speeds is a really bad idea.
I have an old book, "Flight in Cosmic Space", written in 1952 by Russian scientist Ari Sternfeld, where he analyzes, among other concepts, the idea you have proposed. A practical accelerator to send a ship into space would have to reach a 100km height and have a curvature radius so great that it would be several thousands kilometers in length.
Well what I would say to that is that they had nowhere near the engineering ability in 1952 that we do today, especially in the realms of maglev and tower construction. I suggest you read the link to the tower launch archive I supplied.
As for the proposed skyramp idea, I'm all for it. From what the link says, what you'r essentially doing is building a diagonal runway to "...propel an RLV on a sled to supersonic speeds up a long inclined track before the RLV fires its engines.". It seems a bit like the system aircraft carriers use, albeit scaled up:
Eh I'm not in favour of the skyramp idea myself, its too limited in value for any kind of return on the effort you put into it.
It's not a space elevator equivalent however. What you're doing here is more akin to replacing the boosters on a shuttle-type craft with a different system to help it attain orbit.
Yes, a system of cheap earth-based electricity not carried aboard the spacecraft.
With a space elevator, assuming the endpoint was far enough away, you could send something up with enough force to escape the Earth's gravity well. What's more, the longer the cable, the more forcibly the craft can be launched. That alone makes it an attractive concept, and it's something that neither of the ideas you've linked seems to replicate (feel free to correct me if I've misread them).
Well the tower launch with rail-assisted acceleration is entirely my own idea, nuclear power plants and all.:D The thing is you don't need a great deal of force, and you don't need to escape the earth's gravity well in one fell swoop either. You just need to get to LEO and above the atmosphere cheaply; from there you can shunt up as many components as you feel you need, until you have whatever craft you desire. From there, you can go wherever you like a great deal easier than from the earth's surface.
I'm not sure we can build a space elevator - we'd need a great deal of R&D into materials engineering to even consider it.
Yes, but I feel the tower launch has got a great deal of potential here, today. The idea of an 11km tall pylon is so alien to most people that its taking a while to gain a little traction, however.
But unlike the person I replied to, I'm all in favour of trying, and I do not think we'll have a better system developed that can do the same job.
Well the way I understand it, its unlikely that we will ever develop the system for a space elveator. Possible, but unlikely. At least this century. Again, the components for a tower assisted launch exist today; three winged silver needles bursting into the sky, how can you go wrong?:D If someone builds a space elevator tomorrow, I'll be the happiest one here. IN lieu of this, however, I think a tower launch is the best chance we have.
In the last discussion we had. You're getting very close to troll territory my friend.
REPOST:
With all the talk lately about a space elevator, I got to thinking after recent slashdot discussion, just what advantages would a space elevator offer over a tower launch? I contacted the man responsible for a similar idea, the skyramp, (warning: hideous javascript menu may break firefox), Carlton Meyer, and had a dialogue in which he pointed me to the tower launch archive.
The ideas I see bandied about there are similar to what I had in mind, which would be essentially an 11km tall tower (think pylons rather than skyscrapers, based at sea), with evacuated airless launch tubes, using nuclear reactors to power a maglev or pulley system to accelerate vessels to escape velocity. These would then emerge above the end of the troposphere [gatech.edu], with it's associated weather and air pressure, and have little to no fuel needed to escape the earth's gravity, meaning you could do a lot more while you were up there. At normal launch accelerations you can get to LEO with very little external propulsion.
Not only would this enable multiple launches daily, it is, unlike the space elevator, readily achievable with today's technology, and financially viable as well. Given NASA had an annual budget of $16.2 billion for 2005 [space.com], and a nuclear power plant costs a cool billion to build, give or take, we could have this up and running in a few years.
Space has got vast, essentially unlimited resources. One recent story pointed out the trillion dollar iron asteroid up there. The thing has about 5 tons of steel for every man, woman and child on earth. And thats just one of god knows how many... billions more?
Once we leap the cost to escape hurdle (as I think I have managed), we can proceed to use these resources. There are several obstacles in the way of this, first of which is zero gee mining, we have no idea how to do it. We can either mine the ore out there, or bring the asteroid back into orbit and slice it up there. Or slice it up and send it back to orbit. I would be opposed to moving it back into orbit for processing, purely for the debris issue. Perhaps a lunar base would have some merit there.
So we set up a mining and processing operation either on the moon or in deep orbit, and start cutting and processing one of those bad boys. Whats the first thing we build? A bigger processing and mining operation. Space exploration, much like the internet, has to be a largely incestuous affair at first, existing solely for its own benefit.
Once we have that mastered, we can move to algae pods in orbit for food production, oxygen refining, and fuel production (biodiesel or chemical engines), all of which can be powered by the immense energy of the sun, and use the raw materials abundantly available in space. Whether you ship that stuff back to earth or use it for further colonisation, its a vital step.
The production of automated scouts is also a high priority; a vast amount of surveyor and prospector drones to sweep and map every square inch of every rock and gas in the system, out to the Oort cloud, and figure out what they are made of. I'd err on the side of quantity rather than quality, still no reason not to have either. This could be combined with deep space observatories that would make hubble look like the end of a coke bottle.
So now we have a manufacturing bridgehead, a good idea of what's interesting out there, and a cheap means to launch to orbit. Actual manned system ships would come next, to either colonise or investigate the system. The rest, as they say, is (future) history.
A lot of this would require automation, robotics, right up to the point when we build a larger manufactory from the orginal small one. Robots would als
Yet within the realm of science, we didn't have to advance much to get from one to the other. We needed an understanding of rocketry, some knowledge of life support, some advances in various engineering disciplines.
So you are telling me that the leap from canvas winged powered kites to putting men on the moon wasn't much of an advance?
Moreso in space since you've got to take into account the limitations imposed by automation, or else deal with the problems associated with long term space habitation and life support, and you've got to get from Earth orbit to wherever it is in the asteroid belt you're planning to mine/build
What limitations? I wasn't proposing an AI to drive them, more like remote piloting with certain systems semi autonomous. With that in mind there are no limitations on automation. And its a whole lot easier to get from earth orbit to wherever than it is to get from the earth's surface to wherever.
Have you checked the price of putting something in even LEO lately? We need to make serious improvements to our launch technology first if we're going to do anything like building stuff in the belt.
Heyyy, wow did you ask the wrong man. Here's an older post I made....
With all the talk lately about a space elevator, I got to thinking after a recent slashdot discussion, just what advantages would a space elevator offer over a tower launch? I contacted the man responsible for a similar idea, the skyramp (warning: hideous javascript menu may break firefox), Carlton Meyer, and had a dialogue in which he pointed me to a tower launch archive.
The ideas I see bandied about there are similar to what I had in mind, which would be essentially an 11km tall tower (think pylons rather than skyscrapers, based at sea), with evacuated airless launch tubes, using nuclear reactors to power a maglev or pulley system to accelerate vessels to escape velocity. These would then emerge above the end of the troposphere, with it's associated weather and air pressure, and have little to no fuel needed to escape the earth's gravity, meaning you could do a lot more while you were up there. At normal launch accelerations you can get to LEO with very little external propulsion.
Not only would this enable multiple launches daily, it is, unlike the space elevator, readily achievable with today's technology, and financially viable as well. Given NASA had an annual budget of $16.2 billion for 2005, and a nuclear power plant costs a cool billion to build, give or take, we could have this up and running in a few years.
Space has got vast, essentially unlimited resources. One recent story pointed out the trillion dollar iron asteroid up there. The thing has about 5 tons of steel for every man, woman and child on earth. And thats just one of god knows how many... billions more?
Once we leap the cost to escape hurdle (as I think I have managed), we can proceed to use these resources. There are several obstacles in the way of this, first of which is zero gee mining, we have no idea how to do it. We can either mine the ore out there, or bring the asteroid back into orbit and slice it up there. Or slice it up and send it back to orbit. I would be opposed to moving it back into orbit for processing, purely for the debris issue. Perhaps a lunar base would have some merit there.
So we set up a mining and processing operation either on the moon or in deep orbit, and start cutting and processing one of those bad boys. Whats the first thing we build? A bigger processing and mining operation. Space exploration, much like the internet, has to be a largely incestuous affair at first, existing solely for its own benef
Countries with ageing populations like Japan have already done a lot of research into the causes of and prevention of senility. As I recall, the upshot was that if a mind isn't used, it atrophies. They put senior citizens into education programs and get them playing computer games, seems to work well so far.
What you're posting is called "handwaiving". You're ignoring major technical or physical hurdles by saying "we can do it in the future".
And what you're doing is called "ignoring history". In 66 years we went from powered flight to landing on the moon. If we really need to do something, we can usually do it in short order.
I did not say we'd overcome this already. We've build small, expensive and heavy vehicles for deep sea exploration. These will not work on Venus as they are now.
Yup, see above. By the time we are colonising Venus, we'll already have deep orbit refineries building whatever we want, but sadly mostly automated and robotic. I mean there is one asteroid up there, just one of who knows how many, with 5 tons of good quality iron for every man, woman and child on earth, Amun something. I'm not suggesting we start shipping up ocean exploration vehicles piecemeal until we have a Venusian city.
Coolant is just used to transport heat from a hot environment to a cold one, then sent back to the hot environment to pick up more heat. Think of it as a conveyer belt.
Yeah that cold environment would be the coolant. Hell if all else fails set up a series of highly insulated chambers to funnel your hot material through. This is not an insurmountable engineering challenge, although it is a large one. And again, I rather suspect the temperature 500 meters below the surface is fairly nippy.
and don't even think of suggesting a space elevator
Oh I'm not, I was always more of a tower launch kinda guy.:D I put space elevators into the "artificial gravity machines" box.
Plus, for all the trouble you're suggesting we go through to avoid dealing with martian gravity, wouldn't it be simpler just to develop medical treatments for bone loss?
Aha yes, thats a better idea. It would make space travel suck though, having to pop a few calcium pills every day. Nasty little dependancy that, in a long term colony. How and ever, I don't think any such treatment exists. Still, a few stories up they seem to have kicked the ass of cancer, so who knows?
Yer, I wasn't advocating burrowing into the topsoil with our bare hands. Pressure is no problem, as you mentioned we have already overcome that issue, and as time goes on, the solutions will become more elegant and require less adjustment on our part. Temperature likewise, if we can create air conditioning on a mass scale, even in locations where there is no "cool" to draw from, we can surely manufacture similar systems for more extreme locations, even if it means manufacturing or extracting the coolants on the Venusian surface. Dump the "hot" the same place it is always dumped; outside. You want power, draw it from those terrific winds, or any number of power sources available in a volatile environment like that. Regarding corrosiveness, thats where you cover it in Venus rock. And keep covering it if need be.
Yes, it would be a difficult existence if we ever had to venture outside, and the cost would be enormous. There will never be sweeping vistas and green fields on Venus.
We can master all of these difficultes; if you can suggest one for gravity, and the effect of a lack of it on our bone structure, let me know!:D
What? The Martian atmosphere is about 1% the density of earths! Hyper sonic wind my arse... These problems you list aren't problems at all, really. The biggest problem I can see is long term attrition to our bones up there, due to a lower gravity. Thats one we really can't avoid.
If there are rocks on Venus, build em out of venus-rocks like eskimos!:D
It doesn't matter how much weight you pull or exercise you do; if that were the case then all anyone would have to do to stay healthy anywhere would be a few hours in the gym every day. Your bones get weaker no matter what you do. The fact is, long term or permanent settlement on Mars is out of reach until we have that problem whipped. Even if it takes two years or three for the full effects to be felt, thats almost no time at all.
Mars has.38 of earths gravity, so instead of 3 months to significant bone deterioration, you have about a year. Thats not long, considering you have basically 0 gravity on the trips out and back, which themselves could take months. Long term colonies on mars are not an option without some sort of gravity adjusting device. Or maybe changes to the human physique, but I think we can do a bit better than that. Ironically, Venus, with 91% of earth's gravity, has the best chance of being colonised, since we can overcome the environmental factors. Not easily, but its doable. Rotating space stations aren't a great idea for a lot of reasons, and I think there was a problem with lateral forces there too.
The problem as I see it isn't so much the cost of getting there then getting back. That just needs propulsion, and we humans have been blowing things up for a long time, and getting better at it daily. The problem is gravity, or rather the lack of it.
I mean, food, we can deal with that, algae pods fed by raw elements floating around. Air, water, no problems, what we can't pull from a comet and launch to the destination of our choice, we can recycle to the Nth degree. Energy, the sun is blazing with the stuff, and in airless environments its more than you will ever need. Yes, for the pedants in the crowd, I know that this stuff doesn't exist right this second; however I can see a clear path to developing all of it, with little in the way of impediments. The big problem that I really can't see a way around is that our bones weaken and become brittle in low-g environments. I don't recall the exact details, but one Russian cosmonaut who was in space for an extended period was unable to even lift his arm when he returned to earth, for fear of it breaking. And that wasn't for too long, either.
Theres no sign of an artificial gravity device, nor even the theoretical underpinnings of one. Space colonisation by humans will remain a dream until we can master that, if indeed it can be mastered. Maybe that "dark matter" that has no effect on the universe except for its gravitational pull? Thats a thought... of course the repercussions of an anti-gravity machine would go far beyond the plot of firefly or star trek, you could possibly use it to lighten a ship, making tremendous velocity changes and speeds a reality, at a low energy cost. Ah well, one can dream.
It's effective precisely because it usually is back-channel...so it avoids pointless public posturing, and allows the people to compromise out of the public eye. This is not always a bad thing...think of the difference between how people act in normal life and how they act on a reality TV show.
Gotta be more interesting than the last months stories on slashdot at any rate. Yeah, fine, mod me whatever, I've got karma in the zillions. I mean what is it, new editorial policies, some kind of "back to roots" effort gone horribly wrong? Welcome to slashdot, home of the buzzweb and the micro-technological niches I wouldn't be interested in even if I was doing a PhD on that particular micro-technological niche. Blah. I'm off to fark.
Oops, can't edit posts on slashdot. Just to clarify what I said about prostitution, I mean sex is just another form of exercise, as far as I am concerned, unless you are actively trying to procreate. I don't use and never have used prostitutes, because I never felt the need to and I recognise that it is largely controlled by criminal gangs for their own betterment, as a form of slavery, which should be stamped out. And I spend a great deal of time in third world countries where prostitution is endemic, so I know what I am talking about. Eh treat this as part of the other post, I hate splitting threads.
Theres always a victim, whether that victim is yourself or the broader risk of a danger to random individuals. And yes, putting people at risk demands punishment, because people will seek to punish perpetrators themselves otherwise. I'm not too sure that prostitution should even be illegal to be honest, making it so brings the criminal and hazardous elements into it. One more hangover from the cankered and rotten victorian age. As far as I'm concerned, its just another form of exercise.
Well your political problems are your own issues, nothing to do with what I am saying. Where a law exists with a punishment for breaking it, that is retribution against the criminal. This revenge is taken in lieu of the offended party taking revenge, which in the time of Hammurabi lead to a rising cycle of blood feuds and battles in the streets. So the king decreed that only he and his appointed agents were allowed to take revenge.
The whole foundation of the law is one of vengeance. What you are talking about is equivalent punishment, not the same thing at all, and certainly not what I am talking about. The punishment merely needs to be sufficiently severe that the injured party feels no need to add further punishment.
Slashdot Mirror
Even better, when you're submitting a story to slashdot as AC, it might be best to omit linking directly to your email address.
Just a thought.
Ye gods, not only did you not read the links, you didn't even read the original post. You use maglev rails, probably three of them, to push the vessel up out of the tower (its a tower, not a platform), powered by a nuclear reactor in the base. This system can indeed blast you to escape velocity in one shot, however you would be dead. So instead we go to the perfectly palatable low earth orbit, from whence you can go anywhere you like.
This was studied in regards to cannon launch - it does work, but is probably too complex to be comercially viable.
:D
Every single time... please read the links, we are not talking about cannon launches here. We are talking about using the length of the tower to accelerate it.
The real killer in these types of designs is the accelarator - electromagnetics just don't work as well as most people think. High velocities are practically unatainable in reality.
Sorry, try again. Plenty of research shows that it can be done. Its just not financially worth it to put a maglev tunnell across the Atlantic ocean. Now 11km on the other hand is eminently feasable...
Space elevators have a low mass throughput rate and high maintainence costs
No, space elevators have no mass throughput rates and no maintenance costs, and thats because they don't exist and are unlkely to exist this century.
Sternfeld's analysis doesn't consider engineering at all, his constraints are based solely on the accelerations that human beings can whitstand.
:D
Yes and you are still coming at it from the "cannon to escape velocity" angle. The power is provided throughout the length of the launch, not in one single jolt, and while you could reach escape velocity with it, anyone in the ship would be pink wallpaper. Useful for certain types of cargo, however. The idea is only to get to LEO.
Physics has a truth that even political ideology cannot deny.
I was always more of a technocracy with direct democracy via proportional representation kinda guy, myself.
And that's that. No matter from which height you launch, orbital velocity is at least several thousand meters per second and that must come from somewhere. Building a 11km high structure just to get rid of those 15% lost to atmospheric drag doesn't seem quite practical to me...
Okay sorry now, you've completely lost the plot here. They are talking about lifting a rocket to the top of a tower and launching it. I am talking about using the length of the tower to accelerate the vessel and compensate for lateral velocity with onboard fuel, a whole other fish. Much much less than would otherwise be needed, however, which means you have more space for other things.
The beauty of it all is that the space elevator seems to be almost within reach, we can build it in less time than it will take us to develop other alternative means for getting into orbit.
There are zero guarantees we can build it at all, or within the next century at any rate. Seems to be almost within reach is just not realisitic in this context. All of the components for the system I propose, however, exist already. Today. Here. Now.
If you accelerate something to escape velocity, it does exactly that: escapes the gravitational attraction of the Earth and never comes back, unless it's decelerated by some unspecified means. And escape velocity at 11km height means it will be burned to ashes very quickly, remember the Columbia. With our current technology level, building a ship that can fly at escape velocity at 11km height is much more difficult than building a space elevator.
Whoops yes sorry, thats what happens when you repost something after several discussion on it. The escape velocity part shouldn't be there, since to reach escape velocity you would need many more gees than the human body could take for too long. And in any case, the high speeds are reached at the point where the ship enters the atmosphere above the troposphere (another editing error, hey this is slashdot, what can you do), so the effects of the atmosphere are greatly reduced. I should really make a website about this.
OTOH, if you want to put something in orbit around the Earth, then you should give it orbital velocity, which means it should have a very high tangential velocity around the Earth. You cannot do that with a vertical tower, unless that tower reaches the synchronous orbit altitude of 36000km, which is the whole idea of a space elevator. Remember, velocity is a vector. It has both magnitude and direction. If you want to reach orbit, it's useless to throw something straight up with a high speed, because it will fall straight down.
Yes, thats angular momentum there, the craft would probably need some kind of power to adjust for that. Far, far less than a standard earth based launch however, which again leads to greatly increased room for other cargo and reduces the cost to orbit.
Well, you may say, let's make the top of the tower curved, so the ship will be accelerated tangentially.
No no, you can't do that. the only place you can have curvature is at the start of the acceleration. Trying to curve the trajectory of a significant mass at those speeds is a really bad idea.
I have an old book, "Flight in Cosmic Space", written in 1952 by Russian scientist Ari Sternfeld, where he analyzes, among other concepts, the idea you have proposed. A practical accelerator to send a ship into space would have to reach a 100km height and have a curvature radius so great that it would be several thousands kilometers in length.
Well what I would say to that is that they had nowhere near the engineering ability in 1952 that we do today, especially in the realms of maglev and tower construction. I suggest you read the link to the tower launch archive I supplied.
As for the proposed skyramp idea, I'm all for it. From what the link says, what you'r essentially doing is building a diagonal runway to "...propel an RLV on a sled to supersonic speeds up a long inclined track before the RLV fires its engines.". It seems a bit like the system aircraft carriers use, albeit scaled up:
:D The thing is you don't need a great deal of force, and you don't need to escape the earth's gravity well in one fell swoop either. You just need to get to LEO and above the atmosphere cheaply; from there you can shunt up as many components as you feel you need, until you have whatever craft you desire. From there, you can go wherever you like a great deal easier than from the earth's surface.
:D If someone builds a space elevator tomorrow, I'll be the happiest one here. IN lieu of this, however, I think a tower launch is the best chance we have.
Eh I'm not in favour of the skyramp idea myself, its too limited in value for any kind of return on the effort you put into it.
It's not a space elevator equivalent however. What you're doing here is more akin to replacing the boosters on a shuttle-type craft with a different system to help it attain orbit.
Yes, a system of cheap earth-based electricity not carried aboard the spacecraft.
With a space elevator, assuming the endpoint was far enough away, you could send something up with enough force to escape the Earth's gravity well. What's more, the longer the cable, the more forcibly the craft can be launched. That alone makes it an attractive concept, and it's something that neither of the ideas you've linked seems to replicate (feel free to correct me if I've misread them).
Well the tower launch with rail-assisted acceleration is entirely my own idea, nuclear power plants and all.
I'm not sure we can build a space elevator - we'd need a great deal of R&D into materials engineering to even consider it.
Yes, but I feel the tower launch has got a great deal of potential here, today. The idea of an 11km tall pylon is so alien to most people that its taking a while to gain a little traction, however.
But unlike the person I replied to, I'm all in favour of trying, and I do not think we'll have a better system developed that can do the same job.
Well the way I understand it, its unlikely that we will ever develop the system for a space elveator. Possible, but unlikely. At least this century. Again, the components for a tower assisted launch exist today; three winged silver needles bursting into the sky, how can you go wrong?
Blah... And possibly yawn as well...
In the last discussion we had. You're getting very close to troll territory my friend.
REPOST:
With all the talk lately about a space elevator, I got to thinking after recent slashdot discussion, just what advantages would a space elevator offer over a tower launch? I contacted the man responsible for a similar idea, the skyramp, (warning: hideous javascript menu may break firefox), Carlton Meyer, and had a dialogue in which he pointed me to the tower launch archive.
The ideas I see bandied about there are similar to what I had in mind, which would be essentially an 11km tall tower (think pylons rather than skyscrapers, based at sea), with evacuated airless launch tubes, using nuclear reactors to power a maglev or pulley system to accelerate vessels to escape velocity. These would then emerge above the end of the troposphere [gatech.edu], with it's associated weather and air pressure, and have little to no fuel needed to escape the earth's gravity, meaning you could do a lot more while you were up there. At normal launch accelerations you can get to LEO with very little external propulsion.
Not only would this enable multiple launches daily, it is, unlike the space elevator, readily achievable with today's technology, and financially viable as well. Given NASA had an annual budget of $16.2 billion for 2005 [space.com], and a nuclear power plant costs a cool billion to build, give or take, we could have this up and running in a few years.
Space has got vast, essentially unlimited resources. One recent story pointed out the trillion dollar iron asteroid up there. The thing has about 5 tons of steel for every man, woman and child on earth. And thats just one of god knows how many... billions more?
Once we leap the cost to escape hurdle (as I think I have managed), we can proceed to use these resources. There are several obstacles in the way of this, first of which is zero gee mining, we have no idea how to do it. We can either mine the ore out there, or bring the asteroid back into orbit and slice it up there. Or slice it up and send it back to orbit. I would be opposed to moving it back into orbit for processing, purely for the debris issue. Perhaps a lunar base would have some merit there.
So we set up a mining and processing operation either on the moon or in deep orbit, and start cutting and processing one of those bad boys. Whats the first thing we build? A bigger processing and mining operation. Space exploration, much like the internet, has to be a largely incestuous affair at first, existing solely for its own benefit.
Once we have that mastered, we can move to algae pods in orbit for food production, oxygen refining, and fuel production (biodiesel or chemical engines), all of which can be powered by the immense energy of the sun, and use the raw materials abundantly available in space. Whether you ship that stuff back to earth or use it for further colonisation, its a vital step.
The production of automated scouts is also a high priority; a vast amount of surveyor and prospector drones to sweep and map every square inch of every rock and gas in the system, out to the Oort cloud, and figure out what they are made of. I'd err on the side of quantity rather than quality, still no reason not to have either. This could be combined with deep space observatories that would make hubble look like the end of a coke bottle.
So now we have a manufacturing bridgehead, a good idea of what's interesting out there, and a cheap means to launch to orbit. Actual manned system ships would come next, to either colonise or investigate the system. The rest, as they say, is (future) history.
A lot of this would require automation, robotics, right up to the point when we build a larger manufactory from the orginal small one. Robots would als
Yet within the realm of science, we didn't have to advance much to get from one to the other. We needed an understanding of rocketry, some knowledge of life support, some advances in various engineering disciplines.
So you are telling me that the leap from canvas winged powered kites to putting men on the moon wasn't much of an advance?
Moreso in space since you've got to take into account the limitations imposed by automation, or else deal with the problems associated with long term space habitation and life support, and you've got to get from Earth orbit to wherever it is in the asteroid belt you're planning to mine/build
What limitations? I wasn't proposing an AI to drive them, more like remote piloting with certain systems semi autonomous. With that in mind there are no limitations on automation. And its a whole lot easier to get from earth orbit to wherever than it is to get from the earth's surface to wherever.
Have you checked the price of putting something in even LEO lately? We need to make serious improvements to our launch technology first if we're going to do anything like building stuff in the belt.
Heyyy, wow did you ask the wrong man. Here's an older post I made....
With all the talk lately about a space elevator, I got to thinking after a recent slashdot discussion, just what advantages would a space elevator offer over a tower launch? I contacted the man responsible for a similar idea, the skyramp (warning: hideous javascript menu may break firefox), Carlton Meyer, and had a dialogue in which he pointed me to a tower launch archive.
The ideas I see bandied about there are similar to what I had in mind, which would be essentially an 11km tall tower (think pylons rather than skyscrapers, based at sea), with evacuated airless launch tubes, using nuclear reactors to power a maglev or pulley system to accelerate vessels to escape velocity. These would then emerge above the end of the troposphere, with it's associated weather and air pressure, and have little to no fuel needed to escape the earth's gravity, meaning you could do a lot more while you were up there. At normal launch accelerations you can get to LEO with very little external propulsion.
Not only would this enable multiple launches daily, it is, unlike the space elevator, readily achievable with today's technology, and financially viable as well. Given NASA had an annual budget of $16.2 billion for 2005, and a nuclear power plant costs a cool billion to build, give or take, we could have this up and running in a few years.
Space has got vast, essentially unlimited resources. One recent story pointed out the trillion dollar iron asteroid up there. The thing has about 5 tons of steel for every man, woman and child on earth. And thats just one of god knows how many... billions more?
Once we leap the cost to escape hurdle (as I think I have managed), we can proceed to use these resources. There are several obstacles in the way of this, first of which is zero gee mining, we have no idea how to do it. We can either mine the ore out there, or bring the asteroid back into orbit and slice it up there. Or slice it up and send it back to orbit. I would be opposed to moving it back into orbit for processing, purely for the debris issue. Perhaps a lunar base would have some merit there.
So we set up a mining and processing operation either on the moon or in deep orbit, and start cutting and processing one of those bad boys. Whats the first thing we build? A bigger processing and mining operation. Space exploration, much like the internet, has to be a largely incestuous affair at first, existing solely for its own benef
Countries with ageing populations like Japan have already done a lot of research into the causes of and prevention of senility. As I recall, the upshot was that if a mind isn't used, it atrophies. They put senior citizens into education programs and get them playing computer games, seems to work well so far.
What you're posting is called "handwaiving". You're ignoring major technical or physical hurdles by saying "we can do it in the future".
:D I put space elevators into the "artificial gravity machines" box.
And what you're doing is called "ignoring history". In 66 years we went from powered flight to landing on the moon. If we really need to do something, we can usually do it in short order.
I did not say we'd overcome this already. We've build small, expensive and heavy vehicles for deep sea exploration. These will not work on Venus as they are now.
Yup, see above. By the time we are colonising Venus, we'll already have deep orbit refineries building whatever we want, but sadly mostly automated and robotic. I mean there is one asteroid up there, just one of who knows how many, with 5 tons of good quality iron for every man, woman and child on earth, Amun something. I'm not suggesting we start shipping up ocean exploration vehicles piecemeal until we have a Venusian city.
Coolant is just used to transport heat from a hot environment to a cold one, then sent back to the hot environment to pick up more heat. Think of it as a conveyer belt.
Yeah that cold environment would be the coolant. Hell if all else fails set up a series of highly insulated chambers to funnel your hot material through. This is not an insurmountable engineering challenge, although it is a large one. And again, I rather suspect the temperature 500 meters below the surface is fairly nippy.
and don't even think of suggesting a space elevator
Oh I'm not, I was always more of a tower launch kinda guy.
Plus, for all the trouble you're suggesting we go through to avoid dealing with martian gravity, wouldn't it be simpler just to develop medical treatments for bone loss?
Aha yes, thats a better idea. It would make space travel suck though, having to pop a few calcium pills every day. Nasty little dependancy that, in a long term colony. How and ever, I don't think any such treatment exists. Still, a few stories up they seem to have kicked the ass of cancer, so who knows?
The layoffs are in Marketing. *cackle* Hey sucks to be them, I wonder if they will replace them in Bangalore.
Strikes me now that Intel finally has a decent product in the marketplace again, they're cutting back on R&D since they're 'in the game' once again.
They are shaving off MARKETING STAFF. Bwahahah! Yes indeed, leave your victim complexes at the door.
Yer, I wasn't advocating burrowing into the topsoil with our bare hands. Pressure is no problem, as you mentioned we have already overcome that issue, and as time goes on, the solutions will become more elegant and require less adjustment on our part. Temperature likewise, if we can create air conditioning on a mass scale, even in locations where there is no "cool" to draw from, we can surely manufacture similar systems for more extreme locations, even if it means manufacturing or extracting the coolants on the Venusian surface. Dump the "hot" the same place it is always dumped; outside. You want power, draw it from those terrific winds, or any number of power sources available in a volatile environment like that. Regarding corrosiveness, thats where you cover it in Venus rock. And keep covering it if need be.
:D
Yes, it would be a difficult existence if we ever had to venture outside, and the cost would be enormous. There will never be sweeping vistas and green fields on Venus. We can master all of these difficultes; if you can suggest one for gravity, and the effect of a lack of it on our bone structure, let me know!
What? The Martian atmosphere is about 1% the density of earths! Hyper sonic wind my arse... These problems you list aren't problems at all, really. The biggest problem I can see is long term attrition to our bones up there, due to a lower gravity. Thats one we really can't avoid.
If there are rocks on Venus, build em out of venus-rocks like eskimos! :D
It doesn't matter how much weight you pull or exercise you do; if that were the case then all anyone would have to do to stay healthy anywhere would be a few hours in the gym every day. Your bones get weaker no matter what you do. The fact is, long term or permanent settlement on Mars is out of reach until we have that problem whipped. Even if it takes two years or three for the full effects to be felt, thats almost no time at all.
Mars has .38 of earths gravity, so instead of 3 months to significant bone deterioration, you have about a year. Thats not long, considering you have basically 0 gravity on the trips out and back, which themselves could take months. Long term colonies on mars are not an option without some sort of gravity adjusting device. Or maybe changes to the human physique, but I think we can do a bit better than that. Ironically, Venus, with 91% of earth's gravity, has the best chance of being colonised, since we can overcome the environmental factors. Not easily, but its doable. Rotating space stations aren't a great idea for a lot of reasons, and I think there was a problem with lateral forces there too.
The problem as I see it isn't so much the cost of getting there then getting back. That just needs propulsion, and we humans have been blowing things up for a long time, and getting better at it daily. The problem is gravity, or rather the lack of it.
I mean, food, we can deal with that, algae pods fed by raw elements floating around. Air, water, no problems, what we can't pull from a comet and launch to the destination of our choice, we can recycle to the Nth degree. Energy, the sun is blazing with the stuff, and in airless environments its more than you will ever need. Yes, for the pedants in the crowd, I know that this stuff doesn't exist right this second; however I can see a clear path to developing all of it, with little in the way of impediments. The big problem that I really can't see a way around is that our bones weaken and become brittle in low-g environments. I don't recall the exact details, but one Russian cosmonaut who was in space for an extended period was unable to even lift his arm when he returned to earth, for fear of it breaking. And that wasn't for too long, either.
Theres no sign of an artificial gravity device, nor even the theoretical underpinnings of one. Space colonisation by humans will remain a dream until we can master that, if indeed it can be mastered. Maybe that "dark matter" that has no effect on the universe except for its gravitational pull? Thats a thought... of course the repercussions of an anti-gravity machine would go far beyond the plot of firefly or star trek, you could possibly use it to lighten a ship, making tremendous velocity changes and speeds a reality, at a low energy cost. Ah well, one can dream.
It's effective precisely because it usually is back-channel...so it avoids pointless public posturing, and allows the people to compromise out of the public eye. This is not always a bad thing...think of the difference between how people act in normal life and how they act on a reality TV show.
What a shit political system.
Their pricing scheme is not competitive with any other OS's on the market that I can think of.
Vendor Lock In.
Gotta be more interesting than the last months stories on slashdot at any rate. Yeah, fine, mod me whatever, I've got karma in the zillions. I mean what is it, new editorial policies, some kind of "back to roots" effort gone horribly wrong? Welcome to slashdot, home of the buzzweb and the micro-technological niches I wouldn't be interested in even if I was doing a PhD on that particular micro-technological niche. Blah. I'm off to fark.
/know what I mean?
Touché sir!
Bravo!
Oops, can't edit posts on slashdot. Just to clarify what I said about prostitution, I mean sex is just another form of exercise, as far as I am concerned, unless you are actively trying to procreate. I don't use and never have used prostitutes, because I never felt the need to and I recognise that it is largely controlled by criminal gangs for their own betterment, as a form of slavery, which should be stamped out. And I spend a great deal of time in third world countries where prostitution is endemic, so I know what I am talking about. Eh treat this as part of the other post, I hate splitting threads.
Theres always a victim, whether that victim is yourself or the broader risk of a danger to random individuals. And yes, putting people at risk demands punishment, because people will seek to punish perpetrators themselves otherwise. I'm not too sure that prostitution should even be illegal to be honest, making it so brings the criminal and hazardous elements into it. One more hangover from the cankered and rotten victorian age. As far as I'm concerned, its just another form of exercise.
Well your political problems are your own issues, nothing to do with what I am saying. Where a law exists with a punishment for breaking it, that is retribution against the criminal. This revenge is taken in lieu of the offended party taking revenge, which in the time of Hammurabi lead to a rising cycle of blood feuds and battles in the streets. So the king decreed that only he and his appointed agents were allowed to take revenge.
The whole foundation of the law is one of vengeance. What you are talking about is equivalent punishment, not the same thing at all, and certainly not what I am talking about. The punishment merely needs to be sufficiently severe that the injured party feels no need to add further punishment.