FYI : gas "transmission" via pipeline DOES suffer from losses : there's friction between the gas and the pipe that slows it down and heats it up. So, there have to be pumping stations...which are powered by...you guessed it...giant engines that run off of natural gas. So basically there ARE "transmission" losses of a certain percent, analogous to the ones that electricial systems have to deal with.
Eww. a 5% change in stock price is not much potential for profit. Would have to do this year round to make any money (because only doing it, without fail or losing money dozens of times over, would you gradually accumulate wealth 5% at a time)
Well, the Federal government is not world renowned for it's efficiency...
But further, there's noise in the signal. I suspect I am not alone here among the slashdotters who are thinking "hmm, how hard would it to be to make money off of this? Just curious...". What if a few of us acted? Just have to buy a few hundred bucks worth of options on stocks that there seems to be a lot of spam about, yet it needs to be still early enough for there to be some action left. Is it illegal to play the game if you aren't the one pumping the stock? Have to sell earlier than the spammers, of course : setting a low threshold for profit, but could probably make some money.
Right, and in the future, where manufacturing even ordinary objects atom by atom is practical, the future society would have ubiquitous surveillance. EVERY object everywhere would generate ultrahigh res images of everything around it, and nano-scale processors embedded in the objects would analyze the images. Crime would be impossible : even committing a crime would be impossible, as an attempt to commit a major crime would automatically cause an intervention by the AIs watching over everything.
I'm disappointed with the comments on this article : no-one has mentioned the TECHNICAL problems here. Quite simply, this expensive and complex laser system only defends against a very specific type of missile : IR guided SAMs. I would have thought that the smart people here would have immediately pointed out : what about radar guided shoulder launched missiles? I'm sure there must already be a russian radar guided variant. In addition, today there are single chip Doppler radar systems that could easily fit inside a SAM nose cone : how hard would it be for a smart terrorist to re-engineer a missile to have a different kind of guidance? Although home-brewing a radar seeker is probably a big job, the control algorithms to slew the missile are already in the missile's firmware. Hacking this to allow for input of signals from a manual remote control system should be pretty simple and no more complex than the mods posted here every day.
Doing this, the terrorists would be able to control the missile via a joystick.
OR...go cheap and easy and put a bomb on the plane, maybe in the cargo hold. Think of how easy this would really be : just go apply for a JOB as a baggage handler! A baggage handler could probably slip a nuke on a plane.
No, it isn't a toss-up. That price tag includes the enormous R&D costs. Making an n+1 copy of the satellite will be far cheaper. Further, they may even have a partial copy of the satellite hardware already built, on earth, in order to do diagnostics or for prototyping purposes.
No shit. Nuclear "waste" isn't that : it's highly energetic nuclear fuel with at least 99% of it's energy un-released. The problem is that fear of nuclear proliferation and crude technology prevents us from using the rest of that energy except in the rare breeder reactor.
Of course, just how radioactive will nuclear waste be in even 1000 years, anyway? Most of the hot stuff, by definition, has a relatively short half life. By the time 1000 years have passed, it should be relatively safe. Just don't eat any of it, or spend too much time in the mines...no more dangerous than radon deposits that occur naturally.
I am a fan of the Singularity, however, even though I think due to technical problems it may take a century or 2 to happen rather than just 30 years. I think worrying about nuclear waste disposal is stupid. Once we can create beyond human intelligence, we'll quickly develop technology and resources so vast to make the issue a joke.
Well, there's another element to this. 10 years of imprisonment including violations of one's person such as possible rape, years of experiencing fear and other psychological pressures, as well as other pressures since a human being (the guards) control you have their own economic value.
If a private corporation beat you up ONCE you could sue for a tens of thousands of dollars. If a company locked you in a cage and anally violated you I suspect the judgement for the 'worth' of this pain and suffering to be several million dollars. Let's be conservative and say that 10 years of pain and suffering, wrongly inflicted by an entity that can be sued (unfortunatly, the government usually cannot - otherwise all those people who were falsely imprisoned should be able to sue) is worth 1 million dollars.
10% of 1 million is $100,000. It isn't worth it.
Ironically, it most certainly IS worth committing white colar crime across state lines such as fraud and securities violations. Typically you can make several million doing this, and this experience of being imprisoned is in federal facilities without bars or guard towers.
That's exactly what I am saying. I am saying the vast majority of Islamics are degenerates who literally believe that they should kill those who don't believe in their religion, and subjugate women. It's no different than tribes in Africa murdering each other by the millions.
Why is fusion receiving such a tiny (relatively speaking) amount of funding? Why is the Western world not rushing the project. At a risk of sounding cliched, it seems to me that if the 300-500 billion thus far spent on the Iraq war had gone into fusion research, we could have 10-20 different experimental approaches (essentially, trying all the major possible reactor designs) and commercial reactors in a few years.
Not to mention the obvious superiority of spending billions educating the horde of scientists and engineers and computer programmers and managers and other technical workers that would need to be trained for a big project like this. Instead, we spend that money training young men and women how to fight and perform military tasks. The thousands of technical workers that would be produced from an all-out effort for fusion would be extremely useful in achieving the next level of technological breakthroughs.
War damaged soldiers come home, often with permanent injuries, and may never reach their potential. I am in the Army National guard, and I've seen it happen time and time again. Surprisingly few people take advantage of their GI Bill to actually finish a degree.
Oh, and the middle east would be irrelevant. Without money from oil, they would be unable to buy advanced weapons or commit international terrorism, and would basically be another degenerate culture like most of Africa. Sure, they'd kill each other : but we would be able to safely stand back and occasionally drop in food to the refuge camps.
Ok, for all the nay-sayers : here's a pdf showing how laser launch works and WHERE TO BUY THE PARTS TODAY! http://www.niac.usra.edu/files/library/meetings/fe llows/mar04/897Kare.pdf
You know, because we can make one of these today, not next century cuz we actually have available everything we need.
M """"""And how horrendously expensive will those be? How short will their life be? How much maintence will they need? What conditions will they need to function properly? Lasers are decently fragile and expensive, the more powerful the worse the problem. Not to mention the possible problems of powerful lasers such as accidentally scattering and blinding a quarter of the people for 60 miles."""
Nothing on the spacecraft is reflective enough to blind anyone at a long distance. The inverse square law works nicely here. Launch site is located miles from onlookers. Lasers are solid-state and pumped by LED diodes. While pulse lasers are not yet available, continuous duty ones with sufficient power output can be purchased off the shelf today, with working continuous lifespans in the thousands of hours. A working launch system would cost a few billion dollars at current prices.
'''So you need to have safety systems to bring the plane down from that half mile if the lasers don't see it. Very good aiming systems for the lasers so they don't accidentally cook the ship. A very good stabilizing system for the craft so the lasers don't miss and accidentally send the ship of course. The inert block will of course burn off so you will need to design it so it doesn't suddenly fall off and result in your payload getting cooked.'''"""
The stabilizing comes mostly from data sent from the craft back to the ground as to what accelerations it is experiencing. The lasers continuously readjust to create the appropriate thrust pattern. All this 'very good' stuff is just some good real time software, current computers, and good servos guiding the mirrors to focus the ten thousand lasers. Each laser module has it's own mirror. Everything is redundant this way, and malfunctioning modules would be shut down. The cost of this is already included in the price tag. A launch tower could be used, it just increases the number of lasers you need.
""""So are you going to laser it all the way to Geosynchronous orbit or are you going to magically give it a sideways push so it can stay in LEO?""""
No magic - lasers are on a mountain and the craft does gain enough velocity by traveling an appropriate trajectory. Simulations of this are available. The laser launch system would be designed for almost continuous duty, launching one capsule after another all day long.
""""That is impossible, anything this complex will require so much upkeep it's not even funny.""""
So you deny that your hard disk servos keep itself going all the time? The laser modules are INDEPENDENT. Broken modules can be maintained while the rest keep the output going. Multiple control centers and computer systems would of course also be needed.
""""Since 19 of those 20 probes will fail and the last one will barely get any data before failing, space is a very hostile environment.""""
Well, there would be some precautions taken, but in general a 50% failure rate might be perfectly acceptable. It would still cost a lot less money than it would today.
Tracking the craft is probably solvable, but focusing several thousand high power lasers through the atmosphere *AND* dealing with the distortions from other lasers probably isn't.
Actually, this has been dealt with. There are group trying to do this, and they quote a price tag of a few billion dollars having actually CALLED THE DISTRIBUTORS for the parts. Notice that last bit. That's right, all the major components such as the mirrors to focus the light, the tracking system, the lasers, power supplies, and so forth can be PURCHASED (not designed, bought off the shelf) today.
The distortions are actually quite easy to deal with. Adaptive optics used in telescopes have done this for years. Go read up on it.
Technically, when I said linear accelerator I meant something like a steam driven catapault. No reason to use superconducting magnets if you don't have to.
You forget that with a space elevator, you still use 30% efficient lasers, followed by less than 50% efficient photovoltaic panels, and THEN power the DC motors.
Actually, you only take a tiny fraction of the reaction mass that is needed in conventional rockets. This is because a far higher temperature is reached by the escaping propellant than would be generated by combustion.
So, no, this is the best approach by an enormous margin.
What you aren't taking into account is that with lasers, we can make the temperature of the planar shock waves, and therefore the momentum imparted by the departing particles, far far higher.
In the rough sketches I have seen, the Isp would be about 5 times higher. That radically reduces the amount of propellant we have to throw away. In addition, we have no rocket engine to lift and no fuel tanks to hold liquified gasses.
Still a crappy hack, and not worth pursuing : as another story posted today points out, we can get a LOOOOOTTT of energy from nuclear breeder reactors, or orbital power stations. Energy usage is not really that big of an issue. Also, a laser launch system rocket lifts propellant, not fuel, and a LOT less of it. It also does not have to lift a rocket engine. That saves a ludicrious amount of energy right there.
Doesn't understand the conversation? I'm just a little irritated at the lack of vision of/.ers. I think I've just established quite well why a space elevator is NOT the easiest or cheapest way to move stuff : Pros: Yes, ratcheting slowly may use less total energy. But since when has energy ever been the main driver of cost in space travel? Cons :
Space elevator is vulnerable to damage. One break anywhere and the whole thing is kaput. Unless you are proposing self repair bots and sensors and other very complex, non-existent technology to also monitor and repair the whole thing, a failure could happen at any time.
Space elevator has a fiendishly complicated assembly process.
Materials to make the cable aren't just unobtainium, one thing YOU don't understand is that to order carbon such that it has this much tensile strength involves a tremendous change in entropy. By it's very nature, every gram of actual elevator cable would cost a tremendous amount of energy to manufacture due to the difficulties in ordering every atom. Have you read about how much energy it takes to make a single silicon chip?
Space eleavator is slow and low capacity. Since you cannot put any more cars on the cable than the cable has in surplus tensile strength (most of the strength is already in use just to hold itself together) this factor cannot be changed.
This in itself makes it useless, a con that ends the entire project. With the same level of funding needed to build an elevator a laser launch system with hundreds of times the capacity could be constructed. It would be like installing a telephone system using 1920s grade cable when you have multi-mode fiber optic available.
- A quick aside : a laser launch system would take about 10 minutes to launch a payload. It is difficult to see why any society would want a space elevator technology that is 600 to 3000 times slower, yet costs approximately the same. (actually, it might cost more to make a space elevator : the technical issues are unknown, as none has ever been built. We know how to make a laser launch system using continuous duty fiber optic lasers pumped by LEDs today)
There's no military use of a really long elevator. Laser weapons have obvious uses. An elevator would be a huge liability, a giant 20,000-100,000 kilometer target. We can't locate the base in the united states.
So STFU, you don't know what you are talking about.
Oh, and the deeply satisfying throaty roar of a rocket blasting off would still be there. It would also still be quite a kick in the pants to ride one of these capsules to orbit, just far cheaper such that many more of us could enjoy a trip. What would you rather do : be stuck in a tiny capsule for WEEKS as it SLOWLY ratchets up, or ride a shaking capsule with a nice solid deep hand of god crushing you into the seat as a couple of extra Gs of accelearation push you into the cushions. There'd still be a countdown and everything : but with less to fail (it would be like "gyros, check. computers, check, enough lasers Go : check : LAUNCH!) and you would not revise the design of the spacecraft but instead make many thousands of identical copies.
That's the whole point. IF the elevator cable EVER fails : and don't kid yourself, ONE missile strike...not even a nuclear missile, something like a long range cruise missile with a payload of shaped HE, and the entire investment is lost.
And that's just deliberate sabotage or attack : accidental losses could cut the cable at any time. Once it's cut, we start over.
My proposed array of lasers on the ground, working in parallel (there would be a _LOT_ of them, at least 10,000 separately powered and housed lasing modules, maybe 100,000 to approach the output of the space shuttle) would be far less vulnerable. If one laser fails, you shut it down and fix it. You still have the other 9,999 working and available to launch something else.
So it isn't just cost : you can blast stuff into space over and over and over. You could easily launch enough cargo to establish a full industrial plant on the moon, or muster together a massive ship to actually go to Mars and stay there. Space power stations would be feasible.
And military applications : Star wars would actually be practical. We could put enough laser or microwave power beaming stations in space to dominate the Earth. ICBMS, and possible aircraft and missiles would be obsolete.
So the OUTPUT is also FAR higher, enough to actually make a real difference. Screw Space elevators, it's no better idea than using a giant cannon to get to space.
Oh, and one finally carrot : think about the sort of defense applications 'cutting', highly accurate weapons grade pulse lasers could be used for. Remember, I'm proposing basically taking the super high output pulse laser being developed for the Joint Strike Fighter, one that currently uses a secret breakthrough in technology, and making at least 10,000 copies - after redesigning it to be very cheap to manufacture.
That has obvious defense applications, since these lasers would be ubiquitous enough to deploy in military applications everywhere. Every new drone aircraft would be armed with one, there would be batteries all over the place such as in space and near major cities, ect, ect.
Why do people even waste their time on this idea. WHY DO WE NEED SPACE ELEVATORS?
For all the engineers here: why would you want to build a cable tens of thousands of miles long out of currently UNAVAILABLE materials (unobtanium) to slowly ratchet up one payload at a time? It's a horrid idea, and it STILL takes just as much actual energy to put anything in orbit...just it does so pathetically slowly.
The plan is to use PHOTOVOLTAIC PANELS to receive the energy being beamed from the ground. That is a patheticaly slow method of energy conversion considering the payload still has to receive the equivalent energy of being accelerated to several miles/second!
There's a simple and really OBVIOUS idea that has been on the drawing board for at least a decade. It would involve a heck of a lot less work, be likely much simpler and cheaper, and be flat out cool.
Instead of building just a few lasers to beam the energy, lets make a whole bunch of them and use the latest electrically powered pulse laser technology being developed for the joint strike fighter. Our spacecraft is just a payload module with stabiliers BOLTED to a block of inert material. A very short and simple linear accelerator kicks the spacecraft about half a mile into the air, high enough for all the lasers spread across the industrial plant infrastructure to 'see' it.
Pulses of light vaporize the fuel in a sequence such that the shock wave of superheated vaporized gas is planar : basically a rocket engine without needing :
A nozzle pumps, combustion chambers, volatile fuel, electrical systems, elaborate control systems and sensors, just enormouse amounts of hardware gets taken out of the spacecraft and left sitting on the ground. Sure, there's a LOT more delicate hardware left sitting on the ground...WHERE IT BELONGS. The laser launch system would be designed for almost continuous duty, launching one capsule after another all day long. Spacecraft would be MUCH simpler, and with a lower cost of launch could be made MUCH more cheaply as well. After all, why bother with all the checks and cleanrooms if you can send 10-20 Mars probes for the price of what 1 costs today? No need to shave every gram if launches only cost about 20 bucks a kilogram instead of about 1-10 thousand.
And finally, after testing this laser launch system by actually launching thousands and thousands of missions to find out what the REAL failure rate is, and gradually scaling it up to launch bigger, but just as simple, spacecraft we use it for manned missions as well.
Seems like a no-brainer approach. I think the current planning for space travel is like trying to transport goods by horse and buggy across the continent on a massive scale when the same money could be used to install a railroad.
Another issue : the waste issue is a fake boogeyman. Realistically, it's NOT that dangerous. One thing that the news media doesn't understand, even though this is only one step beyond common sense, is that long half life radioactive materials are not that dangerous. This is because the longer an isotope takes to decay, the less radiation it releases at any given time. (Doh!)
So actually, we aren't screwing anyone over : even if we do end up burying waste in a mountain, in 100 years it won't be much more dangerous that NATURAL uranium and radon deposits.
Hey, even that would mean something to Archaelogists. They would conclude that there was a shortage of attractive young women compared to bright young men in the era we are talking of. They might deduce that this shortage was due to the ready availability of junk food, or some other factor.
In the future, it might be different - cosmetic changes of body composition and apparent age might be trivial rather than elaborate, dangerous rituals as practiced today.
Slashdot Mirror
FYI : gas "transmission" via pipeline DOES suffer from losses : there's friction between the gas and the pipe that slows it down and heats it up. So, there have to be pumping stations...which are powered by...you guessed it...giant engines that run off of natural gas. So basically there ARE "transmission" losses of a certain percent, analogous to the ones that electricial systems have to deal with.
Eww. a 5% change in stock price is not much potential for profit. Would have to do this year round to make any money (because only doing it, without fail or losing money dozens of times over, would you gradually accumulate wealth 5% at a time)
Well, the Federal government is not world renowned for it's efficiency... But further, there's noise in the signal. I suspect I am not alone here among the slashdotters who are thinking "hmm, how hard would it to be to make money off of this? Just curious...". What if a few of us acted? Just have to buy a few hundred bucks worth of options on stocks that there seems to be a lot of spam about, yet it needs to be still early enough for there to be some action left. Is it illegal to play the game if you aren't the one pumping the stock? Have to sell earlier than the spammers, of course : setting a low threshold for profit, but could probably make some money.
Right, and in the future, where manufacturing even ordinary objects atom by atom is practical, the future society would have ubiquitous surveillance. EVERY object everywhere would generate ultrahigh res images of everything around it, and nano-scale processors embedded in the objects would analyze the images. Crime would be impossible : even committing a crime would be impossible, as an attempt to commit a major crime would automatically cause an intervention by the AIs watching over everything.
I'm disappointed with the comments on this article : no-one has mentioned the TECHNICAL problems here. Quite simply, this expensive and complex laser system only defends against a very specific type of missile : IR guided SAMs. I would have thought that the smart people here would have immediately pointed out : what about radar guided shoulder launched missiles? I'm sure there must already be a russian radar guided variant. In addition, today there are single chip Doppler radar systems that could easily fit inside a SAM nose cone : how hard would it be for a smart terrorist to re-engineer a missile to have a different kind of guidance? Although home-brewing a radar seeker is probably a big job, the control algorithms to slew the missile are already in the missile's firmware. Hacking this to allow for input of signals from a manual remote control system should be pretty simple and no more complex than the mods posted here every day.
Doing this, the terrorists would be able to control the missile via a joystick.
OR...go cheap and easy and put a bomb on the plane, maybe in the cargo hold. Think of how easy this would really be : just go apply for a JOB as a baggage handler! A baggage handler could probably slip a nuke on a plane.
No, it isn't a toss-up. That price tag includes the enormous R&D costs. Making an n+1 copy of the satellite will be far cheaper. Further, they may even have a partial copy of the satellite hardware already built, on earth, in order to do diagnostics or for prototyping purposes.
No shit. Nuclear "waste" isn't that : it's highly energetic nuclear fuel with at least 99% of it's energy un-released. The problem is that fear of nuclear proliferation and crude technology prevents us from using the rest of that energy except in the rare breeder reactor.
Of course, just how radioactive will nuclear waste be in even 1000 years, anyway? Most of the hot stuff, by definition, has a relatively short half life. By the time 1000 years have passed, it should be relatively safe. Just don't eat any of it, or spend too much time in the mines...no more dangerous than radon deposits that occur naturally.
I am a fan of the Singularity, however, even though I think due to technical problems it may take a century or 2 to happen rather than just 30 years. I think worrying about nuclear waste disposal is stupid. Once we can create beyond human intelligence, we'll quickly develop technology and resources so vast to make the issue a joke.
Well, there's another element to this. 10 years of imprisonment including violations of one's person such as possible rape, years of experiencing fear and other psychological pressures, as well as other pressures since a human being (the guards) control you have their own economic value.
If a private corporation beat you up ONCE you could sue for a tens of thousands of dollars. If a company locked you in a cage and anally violated you I suspect the judgement for the 'worth' of this pain and suffering to be several million dollars. Let's be conservative and say that 10 years of pain and suffering, wrongly inflicted by an entity that can be sued (unfortunatly, the government usually cannot - otherwise all those people who were falsely imprisoned should be able to sue) is worth 1 million dollars.
10% of 1 million is $100,000. It isn't worth it.
Ironically, it most certainly IS worth committing white colar crime across state lines such as fraud and securities violations. Typically you can make several million doing this, and this experience of being imprisoned is in federal facilities without bars or guard towers.
That's exactly what I am saying. I am saying the vast majority of Islamics are degenerates who literally believe that they should kill those who don't believe in their religion, and subjugate women. It's no different than tribes in Africa murdering each other by the millions.
Why is fusion receiving such a tiny (relatively speaking) amount of funding? Why is the Western world not rushing the project. At a risk of sounding cliched, it seems to me that if the 300-500 billion thus far spent on the Iraq war had gone into fusion research, we could have 10-20 different experimental approaches (essentially, trying all the major possible reactor designs) and commercial reactors in a few years.
Not to mention the obvious superiority of spending billions educating the horde of scientists and engineers and computer programmers and managers and other technical workers that would need to be trained for a big project like this. Instead, we spend that money training young men and women how to fight and perform military tasks. The thousands of technical workers that would be produced from an all-out effort for fusion would be extremely useful in achieving the next level of technological breakthroughs.
War damaged soldiers come home, often with permanent injuries, and may never reach their potential. I am in the Army National guard, and I've seen it happen time and time again. Surprisingly few people take advantage of their GI Bill to actually finish a degree.
Oh, and the middle east would be irrelevant. Without money from oil, they would be unable to buy advanced weapons or commit international terrorism, and would basically be another degenerate culture like most of Africa. Sure, they'd kill each other : but we would be able to safely stand back and occasionally drop in food to the refuge camps.
Just so ya'll know : I REALLY did do that. I searched google for a way to deliberately sign up for spam, and found that site.
Ok, here : http://www.niac.usra.edu/files/library/meetings/fe llows/mar04/897Kare.pdf
No, I want to do this : http://www.niac.usra.edu/files/library/meetings/fe llows/mar04/897Kare.pdf
Ok, for all the nay-sayers : here's a pdf showing how laser launch works and WHERE TO BUY THE PARTS TODAY! http://www.niac.usra.edu/files/library/meetings/fe llows/mar04/897Kare.pdf
You know, because we can make one of these today, not next century cuz we actually have available everything we need.
LOL.
M
""""""And how horrendously expensive will those be? How short will their life be? How much maintence will they need? What conditions will they need to function properly? Lasers are decently fragile and expensive, the more powerful the worse the problem. Not to mention the possible problems of powerful lasers such as accidentally scattering and blinding a quarter of the people for 60 miles."""
Nothing on the spacecraft is reflective enough to blind anyone at a long distance. The inverse square law works nicely here. Launch site is located miles from onlookers. Lasers are solid-state and pumped by LED diodes. While pulse lasers are not yet available, continuous duty ones with sufficient power output can be purchased off the shelf today, with working continuous lifespans in the thousands of hours. A working launch system would cost a few billion dollars at current prices.
'''So you need to have safety systems to bring the plane down from that half mile if the lasers don't see it. Very good aiming systems for the lasers so they don't accidentally cook the ship. A very good stabilizing system for the craft so the lasers don't miss and accidentally send the ship of course. The inert block will of course burn off so you will need to design it so it doesn't suddenly fall off and result in your payload getting cooked.'''"""
The stabilizing comes mostly from data sent from the craft back to the ground as to what accelerations it is experiencing. The lasers continuously readjust to create the appropriate thrust pattern. All this 'very good' stuff is just some good real time software, current computers, and good servos guiding the mirrors to focus the ten thousand lasers. Each laser module has it's own mirror. Everything is redundant this way, and malfunctioning modules would be shut down. The cost of this is already included in the price tag. A launch tower could be used, it just increases the number of lasers you need.
""""So are you going to laser it all the way to Geosynchronous orbit or are you going to magically give it a sideways push so it can stay in LEO?""""
No magic - lasers are on a mountain and the craft does gain enough velocity by traveling an appropriate trajectory. Simulations of this are available.
The laser launch system would be designed for almost continuous duty, launching one capsule after another all day long.
""""That is impossible, anything this complex will require so much upkeep it's not even funny.""""
So you deny that your hard disk servos keep itself going all the time? The laser modules are INDEPENDENT. Broken modules can be maintained while the rest keep the output going. Multiple control centers and computer systems would of course also be needed.
""""Since 19 of those 20 probes will fail and the last one will barely get any data before failing, space is a very hostile environment.""""
Well, there would be some precautions taken, but in general a 50% failure rate might be perfectly acceptable. It would still cost a lot less money than it would today.
Tracking the craft is probably solvable, but focusing several thousand high power lasers through the atmosphere *AND* dealing with the distortions from other lasers probably isn't.
Actually, this has been dealt with. There are group trying to do this, and they quote a price tag of a few billion dollars having actually CALLED THE DISTRIBUTORS for the parts. Notice that last bit. That's right, all the major components such as the mirrors to focus the light, the tracking system, the lasers, power supplies, and so forth can be PURCHASED (not designed, bought off the shelf) today.
The distortions are actually quite easy to deal with. Adaptive optics used in telescopes have done this for years. Go read up on it.
Technically, when I said linear accelerator I meant something like a steam driven catapault. No reason to use superconducting magnets if you don't have to.
You forget that with a space elevator, you still use 30% efficient lasers, followed by less than 50% efficient photovoltaic panels, and THEN power the DC motors.
Actually, you only take a tiny fraction of the reaction mass that is needed in conventional rockets. This is because a far higher temperature is reached by the escaping propellant than would be generated by combustion.
So, no, this is the best approach by an enormous margin.
What you aren't taking into account is that with lasers, we can make the temperature of the planar shock waves, and therefore the momentum imparted by the departing particles, far far higher.
In the rough sketches I have seen, the Isp would be about 5 times higher. That radically reduces the amount of propellant we have to throw away. In addition, we have no rocket engine to lift and no fuel tanks to hold liquified gasses.
Ok, I was wondering where that energy came from.
Still a crappy hack, and not worth pursuing : as another story posted today points out, we can get a LOOOOOTTT of energy from nuclear breeder reactors, or orbital power stations. Energy usage is not really that big of an issue. Also, a laser launch system rocket lifts propellant, not fuel, and a LOT less of it. It also does not have to lift a rocket engine. That saves a ludicrious amount of energy right there.
Doesn't understand the conversation? I'm just a little irritated at the lack of vision of /.ers. I think I've just established quite well why a space elevator is NOT the easiest or cheapest way to move stuff :
Pros: Yes, ratcheting slowly may use less total energy. But since when has energy ever been the main driver of cost in space travel?
Cons :
Space elevator is vulnerable to damage. One break anywhere and the whole thing is kaput. Unless you are proposing self repair bots and sensors and other very complex, non-existent technology to also monitor and repair the whole thing, a failure could happen at any time.
Space elevator has a fiendishly complicated assembly process.
Materials to make the cable aren't just unobtainium, one thing YOU don't understand is that to order carbon such that it has this much tensile strength involves a tremendous change in entropy. By it's very nature, every gram of actual elevator cable would cost a tremendous amount of energy to manufacture due to the difficulties in ordering every atom. Have you read about how much energy it takes to make a single silicon chip?
Space eleavator is slow and low capacity. Since you cannot put any more cars on the cable than the cable has in surplus tensile strength (most of the strength is already in use just to hold itself together) this factor cannot be changed.
This in itself makes it useless, a con that ends the entire project. With the same level of funding needed to build an elevator a laser launch system with hundreds of times the capacity could be constructed. It would be like installing a telephone system using 1920s grade cable when you have multi-mode fiber optic available.
- A quick aside : a laser launch system would take about 10 minutes to launch a payload. It is difficult to see why any society would want a space elevator technology that is 600 to 3000 times slower, yet costs approximately the same. (actually, it might cost more to make a space elevator : the technical issues are unknown, as none has ever been built. We know how to make a laser launch system using continuous duty fiber optic lasers pumped by LEDs today)
There's no military use of a really long elevator. Laser weapons have obvious uses. An elevator would be a huge liability, a giant 20,000-100,000 kilometer target. We can't locate the base in the united states.
So STFU, you don't know what you are talking about.
Oh, and the deeply satisfying throaty roar of a rocket blasting off would still be there. It would also still be quite a kick in the pants to ride one of these capsules to orbit, just far cheaper such that many more of us could enjoy a trip. What would you rather do : be stuck in a tiny capsule for WEEKS as it SLOWLY ratchets up, or ride a shaking capsule with a nice solid deep hand of god crushing you into the seat as a couple of extra Gs of accelearation push you into the cushions. There'd still be a countdown and everything : but with less to fail (it would be like "gyros, check. computers, check, enough lasers Go : check : LAUNCH!) and you would not revise the design of the spacecraft but instead make many thousands of identical copies.
That's the whole point. IF the elevator cable EVER fails : and don't kid yourself, ONE missile strike...not even a nuclear missile, something like a long range cruise missile with a payload of shaped HE, and the entire investment is lost.
And that's just deliberate sabotage or attack : accidental losses could cut the cable at any time. Once it's cut, we start over.
My proposed array of lasers on the ground, working in parallel (there would be a _LOT_ of them, at least 10,000 separately powered and housed lasing modules, maybe 100,000 to approach the output of the space shuttle) would be far less vulnerable. If one laser fails, you shut it down and fix it. You still have the other 9,999 working and available to launch something else.
So it isn't just cost : you can blast stuff into space over and over and over. You could easily launch enough cargo to establish a full industrial plant on the moon, or muster together a massive ship to actually go to Mars and stay there. Space power stations would be feasible.
And military applications : Star wars would actually be practical. We could put enough laser or microwave power beaming stations in space to dominate the Earth. ICBMS, and possible aircraft and missiles would be obsolete.
So the OUTPUT is also FAR higher, enough to actually make a real difference. Screw Space elevators, it's no better idea than using a giant cannon to get to space.
Oh, and one finally carrot : think about the sort of defense applications 'cutting', highly accurate weapons grade pulse lasers could be used for. Remember, I'm proposing basically taking the super high output pulse laser being developed for the Joint Strike Fighter, one that currently uses a secret breakthrough in technology, and making at least 10,000 copies - after redesigning it to be very cheap to manufacture.
That has obvious defense applications, since these lasers would be ubiquitous enough to deploy in military applications everywhere. Every new drone aircraft would be armed with one, there would be batteries all over the place such as in space and near major cities, ect, ect.
Why do people even waste their time on this idea. WHY DO WE NEED SPACE ELEVATORS?
For all the engineers here: why would you want to build a cable tens of thousands of miles long out of currently UNAVAILABLE materials (unobtanium) to slowly ratchet up one payload at a time? It's a horrid idea, and it STILL takes just as much actual energy to put anything in orbit...just it does so pathetically slowly.
The plan is to use PHOTOVOLTAIC PANELS to receive the energy being beamed from the ground. That is a patheticaly slow method of energy conversion considering the payload still has to receive the equivalent energy of being accelerated to several miles/second!
There's a simple and really OBVIOUS idea that has been on the drawing board for at least a decade. It would involve a heck of a lot less work, be likely much simpler and cheaper, and be flat out cool.
Instead of building just a few lasers to beam the energy, lets make a whole bunch of them and use the latest electrically powered pulse laser technology being developed for the joint strike fighter. Our spacecraft is just a payload module with stabiliers BOLTED to a block of inert material. A very short and simple linear accelerator kicks the spacecraft about half a mile into the air, high enough for all the lasers spread across the industrial plant infrastructure to 'see' it.
Pulses of light vaporize the fuel in a sequence such that the shock wave of superheated vaporized gas is planar : basically a rocket engine without needing :
A nozzle pumps, combustion chambers, volatile fuel, electrical systems, elaborate control systems and sensors, just enormouse amounts of hardware gets taken out of the spacecraft and left sitting on the ground. Sure, there's a LOT more delicate hardware left sitting on the ground...WHERE IT BELONGS. The laser launch system would be designed for almost continuous duty, launching one capsule after another all day long. Spacecraft would be MUCH simpler, and with a lower cost of launch could be made MUCH more cheaply as well. After all, why bother with all the checks and cleanrooms if you can send 10-20 Mars probes for the price of what 1 costs today? No need to shave every gram if launches only cost about 20 bucks a kilogram instead of about 1-10 thousand.
And finally, after testing this laser launch system by actually launching thousands and thousands of missions to find out what the REAL failure rate is, and gradually scaling it up to launch bigger, but just as simple, spacecraft we use it for manned missions as well.
Seems like a no-brainer approach. I think the current planning for space travel is like trying to transport goods by horse and buggy across the continent on a massive scale when the same money could be used to install a railroad.
Another issue : the waste issue is a fake boogeyman. Realistically, it's NOT that dangerous. One thing that the news media doesn't understand, even though this is only one step beyond common sense, is that long half life radioactive materials are not that dangerous. This is because the longer an isotope takes to decay, the less radiation it releases at any given time. (Doh!) So actually, we aren't screwing anyone over : even if we do end up burying waste in a mountain, in 100 years it won't be much more dangerous that NATURAL uranium and radon deposits.
I took the liberty of visiting listopt.com and signed you up for about 100 different advertising newsletters. I sure hope you find them interesting.
Hey, even that would mean something to Archaelogists. They would conclude that there was a shortage of attractive young women compared to bright young men in the era we are talking of. They might deduce that this shortage was due to the ready availability of junk food, or some other factor.
In the future, it might be different - cosmetic changes of body composition and apparent age might be trivial rather than elaborate, dangerous rituals as practiced today.