That's kind of what I did- I was hunting and pecking even though I knew where all the keys were. So I just popped the keycaps off and swapped them around. Worked for me.
Of course the people that worked with me hated it. "Let me show you..." (grabs keyboard) "aggggghhhh, what have you done to your keyboard?";-)
Controlled fusion is the classic example
on
What's Always Next?
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· Score: 1
Fifty years ago, it was fifty years away. Now it's only 30 years away! That's great! It's much closer now!
(Or have the predictions just got less accurate now- who can say?)
I would guess that such an array would be composed of a series of pulse lasers firing rapidly in round-robin fashion.
Maybe. However, CW semiconductor lasers are getting rapidly cheaper (heading off below $1/watt- Moore's law); and you're only focusing down below a meter or so at a few hundred kms, so there's no big problem (you can probably gang up 10 inch reflector telescopes and stick the lasers at the eyepiece, roughly speaking.)
Pulsed lasers tend to be expensive- there are some suggestions that they might be getting cheap- but the semis look more definitely promising.
The seats they have 'sold' are on flights already paid for by somebody else.
Really? Do you have any evidence for that. Because it sounds like a lie to me. If it were true then various people in Russia would be facing criminal prosecution.
My understanding of the cost (rather than the price) is that the tourism price very much covered the costs of that seat. The asking price per Soyuz is normally $50-60 million. But the actual costs are far, far below that- the rocket itself costs about $5 million, and then you add launch pad and handling costs on top; Tito didn't quite pay for the whole rocket, but it wasn't that far off- and two other cosmonauts travelled with him.
You seem to be confusing opportunity cost with average cost.
The current research should be in the papers on the highlift website, and you should be able to find pictures of fibers held up against rulers and stuff.
It's not necessarily as big a problem as it sounds though- the vehicle is supposed to absorb the light, not reflect it, so it should really be dark coloured- black even. That means that you would get a lot less light reflected, and you/animals/birds could be a lot closer to it before going blind. And humans don't have any business being within a kilometer of a rocket anyway- that's well within shrapnel range.
However, as a replacement for first stage in a hybrid launching system it could be valuable, and would allow larger payloads to be launched without Saturn V-style boosters.
It might work, for the very highest launch rates, but then everything is cheaper/better at the highest launch rates anyway.
A laser launch would likely be less risky on many fronts, and as soon as each vehicle reaches its target orbit, you simply feed another one to the lasers.
I was seriously considering studying this for an M.Sc., but I turned up some very worrying features. For example, scattered light (let alone reflected light) from the launcher is sufficient to blind people at up to a kilometer. Now you can almost certainly keep people out of the way- but what about birds/bats/animals/insects/fish?
Both schemes also need pretty expensive power supplies; and this adds lots of cost to the launched payload. It's all better on paper than it really would be in reality I feel.
The mass-driver concept pioneered by MIT is one that could provide continuous access to near-Earth orbits with clockwork precision.
Not really practical for earth use I'm afraid. The projectiles would leave the breach doing mach 30 odd and suffer extreme ablation (i.e. tend to burn up); and generate enormous sonic booms. The electronic power handling equipment is exceedingly expensive given the most plausible technology (e.g. using silicon). It might work for getting part of the way to orbital speed, but really, mass drivers work a lot better on the moon, which has much lower escape velocity and no atmosphere.
Another possibility is the laser-launcher. A rocket fueled simply by tanks of water would be heated by a bank of ground-based lasers: the resulting superheated steam would lift the vehicle into the desired orbit.
Yes, laser-launchers look pretty promising. However, at the moment, it looks like rockets are likely to outcompete them; the development costs and initial costs of the rockets are rather lower. But laser-launch is definitely a route that works, and works well; although payload size may be somewhat limited (there's no significant upper limit, but the lasers and power source are expensive- you need roughly 1 MW of power per kg of payload, laser costs maybe $20/watt right now, dropping rapidly, plus the generator costs, so with a tonne of payload, well you can do the maths. And there are some difficulties- light pollution, sound pollution, vehicle cost etc.) Incidentally, water is a good fuel only initially (kinda like the Shuttle's SRBs)- once you've taken off hydrogen is probably the fuel of choice- ISP is high, about 600 seconds is easy to achieve, but single stage to orbit is not quite possible, alas- hydrogen tanks are heavy.
Actually the Soyuz vehicle costs about $5 million right now. Raising the launch rate by an order of magnitude or two would get pretty close to the price you quote, even allowing for launch pad services and such like.
Currently, nanotubes cables are not strong enough to make space elevators, they may never be for all we know. It looks promising but it's premature to start building something without all the ingredients to make the cake rise.
The problem, as I say is the cable. The current state of the art is about 72 GPa threads multiple centimeters long. That's extremely promising. Trouble is, nobody has built a strong rope from those threads yet. Splicing normally loses 20% of the strength; pretty much we need 65 GPa strength to reach orbit- plus a safety factor; but the carbon nanotubes are really slippery right now- sticking or splicing them doesn't seem to work.
The second problem is nearly as bad. The projected cost is maybe $20 billion (for example, nanotubes are thousands of dollars per gram, but you need ~20 tonnes for the initial 'seed' cable).
This means that the cost of putting something up the elevator (which takes a couple of weeks anyway) is projected to be something like $500/kg (bearing in mind that the money would have to be borrowed and repaid, quite a lot of the money is repayments of the loan). That's only slightly better than a rocket can do right now- and incidentally the same nanotube technology probably allows much cheaper/better rockets to be built.
Then there's the radiation problem- the space elevator goes all the way through the Van Allen belts and out the other side. The Van Allen belts are really nasty- the Apollo astronauts got something like 1% of a fatal dose during the few hours they took to go through them, but an elevator goes much, much, much more slowly. That means heavy shielding, but the shielding cuts into the weight that the elevator cable can carry- you're talking about a foot thickness of heavy shielding all around the elevator. So the elevator is mostly only good for freight until you have a really beefy cable (expensive), or unless you can remove the Van Allen Belts (HiVolt is one proposal to do that).
The article makes some very good points, and the route to space that they outline is a plausible one; but they've missed one thing.It's easy to forget that the Ruskies already sell space tourism services.
So this gives another route there- the Ruskies sell a whole bunch of space tourist seats, and grow the market organically. Now, once they've tapped out the multibillionaires, the only way to grow is to cut the launch price; to attract the slightly less rich. The Ruskies are making a pretty decent profit on this at the moment, and if they up the launch rate the cost of the vehicle comes down at about 15% cheaper every time they double production. Now the biggest market is down at about $100,000-$500,000 per trip end, and the Ruskies are well placed to capture it and make a reasonable profit- their kit is cheap, and good.
Of course as they prove out the market, it means that competitors will be able to borrow money to start up their own businesses; at the moment few investors believe that the market is real.
So I don't believe that the RLV market is necessary to actually get us to full-on orbital tourism for the (well-heeled) common man. But it's still a good idea, and I hope it works out too.
RLVs are something that our current energy sources just can't dream to achive. We could build the vehicle that could sustain it, but we currently have no way of powering that vehicle.
Um. You do know that the only reason that the Space Shuttle isn't fully reusable is that Congress wouldn't pony up enough development (not research) budget at the key point in the architecture cycle? That there existed and exists an entirely plausible design based on the same basic technology that the Shuttle uses?
My degree isn't in aerospace engineering
Ok, perhaps you didn't. So why are you stating that something can't be done when you don't actually know about it?
Atleast it was only 909,000:1; count yourself lucky. If it was a million to 1 chance, they happen 9 times out of 10:-)
(According to Terry Pratchett anyway, who also admits that there's a million to one chance of it being a million to one chance- ok here on in it gets complicated;-) )
You're the one confusing money and worth. I'm only talking about money; and I totally agree they are not the same thing. I expect Ghandi was pretty poor; if so was he worthless? No.
You've just stated that you think a human life (presumably including my human life in this) is only worth a bullet immediately after describing how many millions you mistakenly thought I might be worth if I lived to an old age. Then you asked if I 'got the point'. That's a death threat, asshole.
Hey, guess what? The Register article that TacticalJack took this from, says exactly the same thing, in the same words; and TacticalJack apparently used the words as if he said it.
Actually, the reliability does not depend on number of launches. It depends on number of bugs found and fixed. Since this work costs money, it translates into improved reliability after all, as advertised:-)
Excellent point so you're making less money per flight and the outgoings are higher; unfortunate, but you do end up with more reliability. Of course in theory you don't have to fix the problems straight away in some cases; in practice there would be huge pressure to fix them right away.
On the other side of the coin there's also the other points that if you launch more often then you can actually measure the real accident rate. For example, the measured failure rate of the Shuttle is about 2%. Possibly the real failure rate is more like 1% right now- the Challenger accident should not recur. But because we have only launched 115 times or whatever, there's no proof. If you actually launch 400x or something, you'd pretty much know the real rate.
However you will suffer four times as many failures, unless you push the reliability of the design further into 9's.
No, that's wrong. I think the safety and reliability improves as you launch more.
Sure, you'd get more failures per decade, but the death rate would be lower- you'd kill less people.
The real point is that you would be able to fix the bugs in the launch system before more people die. With the Shuttle 7 people die before you even know you have a problem; so the death rate is going to be 7x worse than launching one at a time.
The size of the vehicle depends largely on features such as life support, avionics, engines etc.
All of which scale down well with the number of passengers (except avionics, but that is microelectronics and has made great strides in the past few decades anyway.)
Incidentally, the link that you gave does not support the case that a launch vehicle scaled for one isn't the optimum, although the author doesn't appear to like it. The subtle point you and he has missed is that launching fuel and water and food and stuff is cheaper for a small vehicle too, and for the same reasons.
Re:The beginning of a true Mesh network?
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MIT Roofnet
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Ok, that makes more sense.
Your posting kinda implied that 30ms was more or less inevitable; which certainly isn't the case. In particular I don't know whether you were planning to use satellite TV dishes at each end of the link- that can lower the interference enormously and push up the signal-noise ratio.
I think that the 'space plane' should seat one person. Not atleast two. Not atleast one. One.
The reason is that that means that they would have to launch much more often to launch the same number of people. This means that for compared with the Space Shuttle that seated 7, the cost is almost halved; just from having to launch more.
In addition the planes would be cheaper in absolute terms because they are smaller. (It turns out that smaller rockets are about the same cost as big rockets per kg of payload- everything else being equal; which it seldom is at the moment; for example Pegasus is a small vehicle, but that's a solid vehicle with numerous stages, and it turns out to be very expensive, a liquid fuelled rocket with less stages would be cheaper if launched reasonably often).
This means, in turn that they would have to make proportionately more planes. That in turn gives economies of scale- each time you double the production run, the cost per item goes down by 15%.
It turns out that economies of scale are the most powerful known way to reduce costs- more powerful than reusability or using hydrogen fuel, or anything else.
Of course seating one person has it's problems- we probably don't have a rocket that small anymore, so you have to build a smaller rocket. There are also problems with the smaller size making it harder to fit a person in. But these are mainly difficulties not insoluble problems- pretty much it's much cheaper in the long run to seat one. That means that America might be able to capture space tourism market share from the Ruskies; at the moment the Shuttle is ridiculously more expensive for launching people into space.
You've missed the point slightly. They do something worth their wages to the company they work for. You've heard the phrase "Time is money"- well it's not quite true, it's more like "Money is time x marketability"; but it's close. They get wages for the work they do.
That's really the flaw in the articles analysis of the economics- it's nothing much to do with robotics- mankind has had robotics since the industrial revolution.
No, the real point is that people continue to remain employed because the companies perceive that employing more people will make the company more money. It won't necessarily make more money per employee- but it should make more money over cost. So there is a force that encourages the company to employ more people.
The graph of wealth concentration has been misunderstood- ever since the collapse of the British patriachial empire that existed around the 1900s after the shakeup of the two world wars we have gradually been returning to that state but with Americans in charge (for various reasons mostly relating to economic power)- the people with power have been collecting power and money around them- forming dynasties and gaming the laws and the economics to their advantage.
The robotics is a complete red herring- well almost- robotics is just another game that these guys and gals play.
lawyers, as far as I can tell, have no function at all
Lawyers are like soldiers and armies that companies point at other companies. They are there to try to game the laws as a way to take money off of companies, or prevent other companies taking money off them. Don't forget that laws are just a set of semi-arbitrary rules, and the rules that get made are often up for purchase.
Unfortunately you can't run that particularly protocol on the internet due to excessive timeouts (the internet uses a 30 second timeout), but it's fine for a LAN, uh perhaps WAN.
Slashdot Mirror
Of course the people that worked with me hated it. "Let me show you..." (grabs keyboard) "aggggghhhh, what have you done to your keyboard?" ;-)
(Or have the predictions just got less accurate now- who can say?)
Maybe. However, CW semiconductor lasers are getting rapidly cheaper (heading off below $1/watt- Moore's law); and you're only focusing down below a meter or so at a few hundred kms, so there's no big problem (you can probably gang up 10 inch reflector telescopes and stick the lasers at the eyepiece, roughly speaking.)
Pulsed lasers tend to be expensive- there are some suggestions that they might be getting cheap- but the semis look more definitely promising.
Really? Do you have any evidence for that. Because it sounds like a lie to me. If it were true then various people in Russia would be facing criminal prosecution.
My understanding of the cost (rather than the price) is that the tourism price very much covered the costs of that seat. The asking price per Soyuz is normally $50-60 million. But the actual costs are far, far below that- the rocket itself costs about $5 million, and then you add launch pad and handling costs on top; Tito didn't quite pay for the whole rocket, but it wasn't that far off- and two other cosmonauts travelled with him.
You seem to be confusing opportunity cost with average cost.
The current research should be in the papers on the highlift website, and you should be able to find pictures of fibers held up against rulers and stuff.
It's not necessarily as big a problem as it sounds though- the vehicle is supposed to absorb the light, not reflect it, so it should really be dark coloured- black even. That means that you would get a lot less light reflected, and you/animals/birds could be a lot closer to it before going blind. And humans don't have any business being within a kilometer of a rocket anyway- that's well within shrapnel range.
It might work, for the very highest launch rates, but then everything is cheaper/better at the highest launch rates anyway.
A laser launch would likely be less risky on many fronts, and as soon as each vehicle reaches its target orbit, you simply feed another one to the lasers.
I was seriously considering studying this for an M.Sc., but I turned up some very worrying features. For example, scattered light (let alone reflected light) from the launcher is sufficient to blind people at up to a kilometer. Now you can almost certainly keep people out of the way- but what about birds/bats/animals/insects/fish?
Both schemes also need pretty expensive power supplies; and this adds lots of cost to the launched payload. It's all better on paper than it really would be in reality I feel.
Not really practical for earth use I'm afraid. The projectiles would leave the breach doing mach 30 odd and suffer extreme ablation (i.e. tend to burn up); and generate enormous sonic booms. The electronic power handling equipment is exceedingly expensive given the most plausible technology (e.g. using silicon). It might work for getting part of the way to orbital speed, but really, mass drivers work a lot better on the moon, which has much lower escape velocity and no atmosphere.
Another possibility is the laser-launcher. A rocket fueled simply by tanks of water would be heated by a bank of ground-based lasers: the resulting superheated steam would lift the vehicle into the desired orbit.
Yes, laser-launchers look pretty promising. However, at the moment, it looks like rockets are likely to outcompete them; the development costs and initial costs of the rockets are rather lower. But laser-launch is definitely a route that works, and works well; although payload size may be somewhat limited (there's no significant upper limit, but the lasers and power source are expensive- you need roughly 1 MW of power per kg of payload, laser costs maybe $20/watt right now, dropping rapidly, plus the generator costs, so with a tonne of payload, well you can do the maths. And there are some difficulties- light pollution, sound pollution, vehicle cost etc.) Incidentally, water is a good fuel only initially (kinda like the Shuttle's SRBs)- once you've taken off hydrogen is probably the fuel of choice- ISP is high, about 600 seconds is easy to achieve, but single stage to orbit is not quite possible, alas- hydrogen tanks are heavy.
No problem. Check out the NASA history on the subject; it's reasonably good.
Actually the Soyuz vehicle costs about $5 million right now. Raising the launch rate by an order of magnitude or two would get pretty close to the price you quote, even allowing for launch pad services and such like.
The problem, as I say is the cable. The current state of the art is about 72 GPa threads multiple centimeters long. That's extremely promising. Trouble is, nobody has built a strong rope from those threads yet. Splicing normally loses 20% of the strength; pretty much we need 65 GPa strength to reach orbit- plus a safety factor; but the carbon nanotubes are really slippery right now- sticking or splicing them doesn't seem to work.
The second problem is nearly as bad. The projected cost is maybe $20 billion (for example, nanotubes are thousands of dollars per gram, but you need ~20 tonnes for the initial 'seed' cable).
This means that the cost of putting something up the elevator (which takes a couple of weeks anyway) is projected to be something like $500/kg (bearing in mind that the money would have to be borrowed and repaid, quite a lot of the money is repayments of the loan). That's only slightly better than a rocket can do right now- and incidentally the same nanotube technology probably allows much cheaper/better rockets to be built.
Then there's the radiation problem- the space elevator goes all the way through the Van Allen belts and out the other side. The Van Allen belts are really nasty- the Apollo astronauts got something like 1% of a fatal dose during the few hours they took to go through them, but an elevator goes much, much, much more slowly. That means heavy shielding, but the shielding cuts into the weight that the elevator cable can carry- you're talking about a foot thickness of heavy shielding all around the elevator. So the elevator is mostly only good for freight until you have a really beefy cable (expensive), or unless you can remove the Van Allen Belts (HiVolt is one proposal to do that).
So this gives another route there- the Ruskies sell a whole bunch of space tourist seats, and grow the market organically. Now, once they've tapped out the multibillionaires, the only way to grow is to cut the launch price; to attract the slightly less rich. The Ruskies are making a pretty decent profit on this at the moment, and if they up the launch rate the cost of the vehicle comes down at about 15% cheaper every time they double production. Now the biggest market is down at about $100,000-$500,000 per trip end, and the Ruskies are well placed to capture it and make a reasonable profit- their kit is cheap, and good.
Of course as they prove out the market, it means that competitors will be able to borrow money to start up their own businesses; at the moment few investors believe that the market is real.
So I don't believe that the RLV market is necessary to actually get us to full-on orbital tourism for the (well-heeled) common man. But it's still a good idea, and I hope it works out too.
Um. You do know that the only reason that the Space Shuttle isn't fully reusable is that Congress wouldn't pony up enough development (not research) budget at the key point in the architecture cycle? That there existed and exists an entirely plausible design based on the same basic technology that the Shuttle uses?
My degree isn't in aerospace engineering
Ok, perhaps you didn't. So why are you stating that something can't be done when you don't actually know about it?
Agreed.
So where's the good Star Wars reference? ;-)
never tell me the odds!
Ok. Sorrrrry. ;-)
(According to Terry Pratchett anyway, who also admits that there's a million to one chance of it being a million to one chance- ok here on in it gets complicated ;-) )
You're the one confusing money and worth. I'm only talking about money; and I totally agree they are not the same thing. I expect Ghandi was pretty poor; if so was he worthless? No.
You've just stated that you think a human life (presumably including my human life in this) is only worth a bullet immediately after describing how many millions you mistakenly thought I might be worth if I lived to an old age. Then you asked if I 'got the point'. That's a death threat, asshole.
I sure hope that isn't a death threat in a public forum.
Check it out for yourself here.
Excellent point so you're making less money per flight and the outgoings are higher; unfortunate, but you do end up with more reliability. Of course in theory you don't have to fix the problems straight away in some cases; in practice there would be huge pressure to fix them right away.
On the other side of the coin there's also the other points that if you launch more often then you can actually measure the real accident rate. For example, the measured failure rate of the Shuttle is about 2%. Possibly the real failure rate is more like 1% right now- the Challenger accident should not recur. But because we have only launched 115 times or whatever, there's no proof. If you actually launch 400x or something, you'd pretty much know the real rate.
No, that's wrong. I think the safety and reliability improves as you launch more.
Sure, you'd get more failures per decade, but the death rate would be lower- you'd kill less people.
The real point is that you would be able to fix the bugs in the launch system before more people die. With the Shuttle 7 people die before you even know you have a problem; so the death rate is going to be 7x worse than launching one at a time.
The size of the vehicle depends largely on features such as life support, avionics, engines etc.
All of which scale down well with the number of passengers (except avionics, but that is microelectronics and has made great strides in the past few decades anyway.)
Incidentally, the link that you gave does not support the case that a launch vehicle scaled for one isn't the optimum, although the author doesn't appear to like it. The subtle point you and he has missed is that launching fuel and water and food and stuff is cheaper for a small vehicle too, and for the same reasons.
Your posting kinda implied that 30ms was more or less inevitable; which certainly isn't the case. In particular I don't know whether you were planning to use satellite TV dishes at each end of the link- that can lower the interference enormously and push up the signal-noise ratio.
The reason is that that means that they would have to launch much more often to launch the same number of people. This means that for compared with the Space Shuttle that seated 7, the cost is almost halved; just from having to launch more.
In addition the planes would be cheaper in absolute terms because they are smaller. (It turns out that smaller rockets are about the same cost as big rockets per kg of payload- everything else being equal; which it seldom is at the moment; for example Pegasus is a small vehicle, but that's a solid vehicle with numerous stages, and it turns out to be very expensive, a liquid fuelled rocket with less stages would be cheaper if launched reasonably often).
This means, in turn that they would have to make proportionately more planes. That in turn gives economies of scale- each time you double the production run, the cost per item goes down by 15%.
It turns out that economies of scale are the most powerful known way to reduce costs- more powerful than reusability or using hydrogen fuel, or anything else.
Of course seating one person has it's problems- we probably don't have a rocket that small anymore, so you have to build a smaller rocket. There are also problems with the smaller size making it harder to fit a person in. But these are mainly difficulties not insoluble problems- pretty much it's much cheaper in the long run to seat one. That means that America might be able to capture space tourism market share from the Ruskies; at the moment the Shuttle is ridiculously more expensive for launching people into space.
You've missed the point slightly. They do something worth their wages to the company they work for. You've heard the phrase "Time is money"- well it's not quite true, it's more like "Money is time x marketability"; but it's close. They get wages for the work they do.
That's really the flaw in the articles analysis of the economics- it's nothing much to do with robotics- mankind has had robotics since the industrial revolution.
No, the real point is that people continue to remain employed because the companies perceive that employing more people will make the company more money. It won't necessarily make more money per employee- but it should make more money over cost. So there is a force that encourages the company to employ more people.
The graph of wealth concentration has been misunderstood- ever since the collapse of the British patriachial empire that existed around the 1900s after the shakeup of the two world wars we have gradually been returning to that state but with Americans in charge (for various reasons mostly relating to economic power)- the people with power have been collecting power and money around them- forming dynasties and gaming the laws and the economics to their advantage.
The robotics is a complete red herring- well almost- robotics is just another game that these guys and gals play.
lawyers, as far as I can tell, have no function at all
Lawyers are like soldiers and armies that companies point at other companies. They are there to try to game the laws as a way to take money off of companies, or prevent other companies taking money off them. Don't forget that laws are just a set of semi-arbitrary rules, and the rules that get made are often up for purchase.
Unfortunately you can't run that particularly protocol on the internet due to excessive timeouts (the internet uses a 30 second timeout), but it's fine for a LAN, uh perhaps WAN.