Regarding the very minor effect of computers in schools in (I'm assuming) either US, UK or other developed countries, this is a very different situation.
The purpose of computers in developed-country schools isn't to improve the education as a whole, its to teach the kids Office and keyboarding, and maybe some programming and web design, i.e. computer skills. It's not to improve information access as a whole, because at this point most of those kids are going to have better computers at home they can use, and well stocked libraries, and other great resources for a curious student to take advantage of.
OLPC is intended to teach basic computer skills to some extent, but more as a means of getting access to information that would otherwise be unavailable. The mesh network is a great example of trying to make it so that internet access is available if at all possible. It's loaded up with textbooks (or so I'm pretty sure I've read, I'm no expert) so that they can learn those basic math, science, and history that we take for granted.
I guess basically the point is that OLPC is to provide information access rather than just the 'computer skills' school computers are used for here in the US.
As a graduate student in Aerospace Engineering, I'd disagree with your assessment. Those of us coming up through school now have gotten to know the space program during the 'return to flight' period and we recognize that human space-flight is not a given. It seems to me that the long continuation of the STS created some complacency and 'this is the way its always been done' mentality.
However, the new people coming up aren't as trapped in those paradigms, and I really feel that my generation is up to the challenge of doing what the Apollo generation did, but for cheaper, and in a sustainable way.
While its true that NASA isn't the beacon for intellectual challenge in the workplace that it was seen as in the 60's, I'd say Google best fulfills that role now, there are still plenty of very intelligent, very driven young people coming up in the space industry. We don't believe that the current way of doing things is the right way, and I feel we have the attitude needed, because we know that our failure could very well mean the end of human spaceflight for a long time, not just a 5 or 10 year delay.
With a large portion of the space industry retiring soon (something like 30%-40% in the next 10 years) my generation will be very involved in the future, and I have a lot of hope for what we can do.
Wrong COTS, though I do see what you're saying, even if I prefer that method in the long run (a large number of smaller cheaper cooperative satellites, although there are still cases where you'll need the larger special-built ones, and LandSat definitely sounds like one of them).
This COTS is the Commercial Orbital Transport System, which is a very very good program in my mind, because its funding the development of a much lower cost launch vehicle through a program where success is measured in results, not effort. Saying that, I am a bit of a SpaceX fanboy, but I am so because I feel they have a good chance to really improve the launch business significantly, and launch costs and reliability are still the single biggest driving factor to make space flight cheaper and more commonplace. If only Rocketplane Kistler had managed to keep up, more competition would be better still.
Yet another choice of poor acronyms to confuse things.
SpaceX has gotten close to LEO, they had the velocity, just some GNC problems. Though perhaps not as private as Scaled Composites (they recieved some DARPA funding), its significantly different from the traditional business model behind the Delta series, for instance. Furthermore, I paraphrase that statement from things I've heard from some high-level NASA officials as well as armchair experts like you and I.
As much as I'm a supporter of the New Space industry, government still has a role. Everyone knows that NASA needs to get out of the role of ferrying stuff to LEO. It's possible for companies to make a profit on it now. However, the government still has the role of exploration, the so-called Lewis and Clark role, pushing the boundaries in ways that can't make a short term profit and that are too expensive for individual philanthropists to fund.
So while I'd agree that the current state is problematic, the general concept of a government space program is not without very old historical precedents. I think that SpaceX and the X-Prize guys will be instrumental to getting to the future we need, but it will be in partnership with the government, not in competition with it. From my conversations with various people on both sides this seems to be the general consensus, although of course the details are always up for debate.
Because the DOD has a large number of people around the world, and they want to be able to be prepared for them, since military bases and camps can be hotbeds for disease.
Moore's law works because they're not running into fundamental limits, but running into practical limits of manufacturing capability and cooling. Unfortunately, the cost of space travel is a pretty solid barrier based on physics (specific impulse, combustion chemistry, and delta-v), and the Apollo design was pretty well optimized; the main advantage we have now is lighter computers and better comm equipment. We can also do some controls stuff, but that will only help so much.
Significant reductions in cost and capabilities (beyond an order of magnitude, which could be possible with volume, such as SpaceX's plans) really depend on a completely new propulsion technology. All of the current alternatives are promising but still have glaring limits.
I think the real utility of it isn't just that he's install Ubuntu, but the fact that he's doing the gruntwork to collect old computers, put them in a usable state, and redistributing them to those in need. Evangelizing for linux isn't necessarily the point.
First, you can still buy individual songs (which I'd rather buy a full album in a physical CD anyway). Second, they plan on porting a linux version of the downloader shortly. Plus, it is only beta (and this isn't Google).
I apologize for the imprecision of my language, like I stated in response to another poster, I believe the specific treaty that blocked further development was a ban on above-ground warhead detonations. The fact that there wasn't an altitude limit meant that it applied all the way out.
However, even if someone really wanted to enforce that now (I'm no expert on international law) I don't think this new version would really count as a warhead, since it's using externally driven magnets to compress the fissile material to critical, and also to contain that explosion and push it in a useful direction.
True, although I think the specific ban was on atmospheric (as opposed to underground) nuclear warhead tests that did in Orion. So even if not a weapon, still technically a warhead.
I think if we really wanted to do this now though, we could get the definitions changed, plus it looks like this isnt using a extra warheads we have lying around, but rather imploding chunks of fissible material using magnets, so it may not technically be a warhead anyway.
Orion operates by exploding a weapon against a thrust plate, so it really qualifies as a weapon, which is at least one reason Orion was cancelled. I'm not sure how the treaty applies to space-based reactors, but theres definitely a large difference between an RTG and reactor as well.
If by Cisco's security software you mean their VPN, there is a linux client, although its a pain to use. But, theres now an open-source client that has worked out beautifully for me called VPNC (sudo apt-get install vpnc, and find specifics on the forums for the four or five line config file).
Cool, yeah, me and my roommate just sat down and figured out that it could work (4:1 mass ratio for a chemical rockets, 1:1 for an EP booster, both from LEO, based on an old project), so if you can pull off ~100 kg you could do a falcon 1 for a chemical system, and you could make a monster, closer to 300 kg if you're willing to take a while with an electric thruster.
Of course, then you get to the robot that's that small and capable, which I don't know as much about it. From what I understand, the point is really to encourage the private robot capabilities, not the getting to the moon part.
$30 million isn't that much in the grand scheme of things, so, if someone wins it, their name is attached to a big news story with lots of good karma, something that no amount of advertising dollars can buy. And if no one wins, they don't have to pay much of anything. Don't underestimate the value of those -50 evil points.
Doing it for something on the order of $30 million is an achievement, same as the Ansari X-Prize wasn't about doing something new, but doing it for cheap without government involvement.
Given the investments of participants from the last one, where Scaled Composites spent $20 Million for a $10 Million prize, I'd expect that if someone does this, it will be for less than $100 million. I would guess that to be able to get a capable robot to the moon would require a launch vehicle on the order of the Falcon 9, which is a priced from $35-$55 million per launch. I haven't done the numbers for the mass fraction (fuel to payload ratio) from LEO or GTO to the moon, so I can't say what the mass of the required robot would be, or even given that, what the launch weight (and therefore costs) would be.
But, still, given launch costs, unless they somehow manage to figure out something that SpaceX and Rocketplane-Kistler haven't, this prize is either just about right, or too little. Certainly not too much. I'm pretty optimistic about it right now, and hope we hear some things about it soon.
There are two reasons to make a really big telescope (whether optical, radio, or even x-ray). FIrst you pick up more photons, allowing you to pick up dimmer, more distant objects and get less noisy data. The second is that you get improved angular resolution, since the limiting factor for resolution on a good telescope is the diffraction of light, a consequence of the wave nature. Simply, the angular resolution is approximated very well by Rayleigh's Formula:
Resolution(radians) = Wavelength/Diameter
When you do this kind of technique, you increase the angular resolution that can be picked up to that of a full telescope over the area (if designed properly to get the middle resolutions as well). However, as others have mentioned, you don't get the full number of photons, which means you have to increase the imaging time or allow for much high SNRs. However, this is still very useful for getting high resolution images of fairly bright objects.
It's an interesting idea, but its a difficult task because relative positions have to be maintained within fractions of wavelengths, so centimeters or millimeters for radio waves. While not technically impossible, doing this over the size of the Earth's orbit is a very difficult engineering task, requiring new tracking technologies and huge amounts of station-keeping fuel and precision.
So at this point, possible but expensive. I could see it as a 50-year-out kind of technology, unless someone decides it really needs to be done soon, and has the influence and money to back it up.
Just to expand on this comment for other readers, any time you do this with any kind of wavelength, you have to have the positions of the telescopes known within fractions of a wavelength. Radio waves range from meters to millimeters, so precision on a worldwide scale is difficult but not impossible at this range , although doing it in real-time is still an impressive feat, as this used to be done by recording the signals to tape, taking them to a central location and processing the data then.
However, expanding it to optical frequencies (where you can pick up different types of objects and also do so to much higher resolution) is difficult, since the wavelengths are around 500 nanometers, a level of precision that is still impossible on worldwide scales, except maybe in space, where you can depend on laser range finding over very long distances, although i don't know of any proposals trying to do this over very large scale.
Well, as long as we're being pedantic, solar wind actually causes a periodic change in altitude, since its being sped up while moving away from the sun, and slowed down when approaching it. Intuition tells me this orbit is slightly egg-shaped (not elliptical, but varying the second focus of the ellipse as it moves).
I'll concede you the density out there isn't quite zero, so you get some eventual decay... I have no idea what the time frame on that is though.
Just to be clear, a GEO satellite doesn't really decay. It will fluctuate and perturb, yes; the N-S drift due to the Sun and Moon are particularly annoying. However, it won't lose altitude like a LEO satellite will since there is no atmosphere at all, not even the very sparse atmosphere that slows down those spacecraft.
Because it allows us to continue to use our MythTV systems without having to rely on screen-scraping.
You may like TiVo, it certainly looks nice, easy to use. But I enjoy having my Myth box because it can do so many more things, even if it is an order of magnitude more difficult to set up (but not necessarily to use). Same as I appreciate OS-X, but I think I'll stick with linux not for the price and commodity hardware, but for the customizability and the ability to tinker. Same reason as I bought my Buffalo router recently to reflash to Open-WRT, its harder but its interesting and inherently more powerful than the stock D-link I used before.
So, this isn't to try and start a conflict, just to explain that I enjoy my mythbox, and I appreciate a new service to keep it working well. You may enjoy your TiVo, as well you should, I just don't think its for me right now, and I'm sure others feel the same.
I think as a permanent price point, $15 for three months is marginal. However, if they keep to their goal of reducing the costs to $20/year, it's not so bad.
I'm pretty sure I'll buy this service, partially because I'd like to avoid the hassles and problems of screen scraping, and partially because I'd like to support this project as I really appreciate them coming up with a solution, even if its not quite as ideal as before.
The difference is is that they're operating by brute force, pushing the object way out of the way. But, a more nuanced subtle approach, characterizing NEO's orbits more and more accurately if they seem to be a threat, and making these small course corrections seems to be a much more responsible approach. I guess its good to have the nuke option on the table if a big one comes out of nowhere with less than a years warning time, or something like that; I guess a long-period object has the potential to do that and be missed until too late.
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Regarding the very minor effect of computers in schools in (I'm assuming) either US, UK or other developed countries, this is a very different situation.
The purpose of computers in developed-country schools isn't to improve the education as a whole, its to teach the kids Office and keyboarding, and maybe some programming and web design, i.e. computer skills. It's not to improve information access as a whole, because at this point most of those kids are going to have better computers at home they can use, and well stocked libraries, and other great resources for a curious student to take advantage of.
OLPC is intended to teach basic computer skills to some extent, but more as a means of getting access to information that would otherwise be unavailable. The mesh network is a great example of trying to make it so that internet access is available if at all possible. It's loaded up with textbooks (or so I'm pretty sure I've read, I'm no expert) so that they can learn those basic math, science, and history that we take for granted.
I guess basically the point is that OLPC is to provide information access rather than just the 'computer skills' school computers are used for here in the US.
As a graduate student in Aerospace Engineering, I'd disagree with your assessment. Those of us coming up through school now have gotten to know the space program during the 'return to flight' period and we recognize that human space-flight is not a given. It seems to me that the long continuation of the STS created some complacency and 'this is the way its always been done' mentality.
However, the new people coming up aren't as trapped in those paradigms, and I really feel that my generation is up to the challenge of doing what the Apollo generation did, but for cheaper, and in a sustainable way.
While its true that NASA isn't the beacon for intellectual challenge in the workplace that it was seen as in the 60's, I'd say Google best fulfills that role now, there are still plenty of very intelligent, very driven young people coming up in the space industry. We don't believe that the current way of doing things is the right way, and I feel we have the attitude needed, because we know that our failure could very well mean the end of human spaceflight for a long time, not just a 5 or 10 year delay.
With a large portion of the space industry retiring soon (something like 30%-40% in the next 10 years) my generation will be very involved in the future, and I have a lot of hope for what we can do.
Wrong COTS, though I do see what you're saying, even if I prefer that method in the long run (a large number of smaller cheaper cooperative satellites, although there are still cases where you'll need the larger special-built ones, and LandSat definitely sounds like one of them).
This COTS is the Commercial Orbital Transport System, which is a very very good program in my mind, because its funding the development of a much lower cost launch vehicle through a program where success is measured in results, not effort. Saying that, I am a bit of a SpaceX fanboy, but I am so because I feel they have a good chance to really improve the launch business significantly, and launch costs and reliability are still the single biggest driving factor to make space flight cheaper and more commonplace. If only Rocketplane Kistler had managed to keep up, more competition would be better still.
Yet another choice of poor acronyms to confuse things.
SpaceX has gotten close to LEO, they had the velocity, just some GNC problems. Though perhaps not as private as Scaled Composites (they recieved some DARPA funding), its significantly different from the traditional business model behind the Delta series, for instance. Furthermore, I paraphrase that statement from things I've heard from some high-level NASA officials as well as armchair experts like you and I.
As much as I'm a supporter of the New Space industry, government still has a role. Everyone knows that NASA needs to get out of the role of ferrying stuff to LEO. It's possible for companies to make a profit on it now. However, the government still has the role of exploration, the so-called Lewis and Clark role, pushing the boundaries in ways that can't make a short term profit and that are too expensive for individual philanthropists to fund.
So while I'd agree that the current state is problematic, the general concept of a government space program is not without very old historical precedents. I think that SpaceX and the X-Prize guys will be instrumental to getting to the future we need, but it will be in partnership with the government, not in competition with it. From my conversations with various people on both sides this seems to be the general consensus, although of course the details are always up for debate.
You know, I know you're trying to be funny, but I really like that idea. I suppose we'll just have to see how the Lunar X-Prize works out.
Because the DOD has a large number of people around the world, and they want to be able to be prepared for them, since military bases and camps can be hotbeds for disease.
Moore's law works because they're not running into fundamental limits, but running into practical limits of manufacturing capability and cooling. Unfortunately, the cost of space travel is a pretty solid barrier based on physics (specific impulse, combustion chemistry, and delta-v), and the Apollo design was pretty well optimized; the main advantage we have now is lighter computers and better comm equipment. We can also do some controls stuff, but that will only help so much.
Significant reductions in cost and capabilities (beyond an order of magnitude, which could be possible with volume, such as SpaceX's plans) really depend on a completely new propulsion technology. All of the current alternatives are promising but still have glaring limits.
I think the real utility of it isn't just that he's install Ubuntu, but the fact that he's doing the gruntwork to collect old computers, put them in a usable state, and redistributing them to those in need. Evangelizing for linux isn't necessarily the point.
First, you can still buy individual songs (which I'd rather buy a full album in a physical CD anyway). Second, they plan on porting a linux version of the downloader shortly. Plus, it is only beta (and this isn't Google).
I apologize for the imprecision of my language, like I stated in response to another poster, I believe the specific treaty that blocked further development was a ban on above-ground warhead detonations. The fact that there wasn't an altitude limit meant that it applied all the way out.
However, even if someone really wanted to enforce that now (I'm no expert on international law) I don't think this new version would really count as a warhead, since it's using externally driven magnets to compress the fissile material to critical, and also to contain that explosion and push it in a useful direction.
True, although I think the specific ban was on atmospheric (as opposed to underground) nuclear warhead tests that did in Orion. So even if not a weapon, still technically a warhead.
I think if we really wanted to do this now though, we could get the definitions changed, plus it looks like this isnt using a extra warheads we have lying around, but rather imploding chunks of fissible material using magnets, so it may not technically be a warhead anyway.
Orion operates by exploding a weapon against a thrust plate, so it really qualifies as a weapon, which is at least one reason Orion was cancelled. I'm not sure how the treaty applies to space-based reactors, but theres definitely a large difference between an RTG and reactor as well.
If by Cisco's security software you mean their VPN, there is a linux client, although its a pain to use. But, theres now an open-source client that has worked out beautifully for me called VPNC (sudo apt-get install vpnc, and find specifics on the forums for the four or five line config file).
Cool, yeah, me and my roommate just sat down and figured out that it could work (4:1 mass ratio for a chemical rockets, 1:1 for an EP booster, both from LEO, based on an old project), so if you can pull off ~100 kg you could do a falcon 1 for a chemical system, and you could make a monster, closer to 300 kg if you're willing to take a while with an electric thruster.
Of course, then you get to the robot that's that small and capable, which I don't know as much about it. From what I understand, the point is really to encourage the private robot capabilities, not the getting to the moon part.
$30 million isn't that much in the grand scheme of things, so, if someone wins it, their name is attached to a big news story with lots of good karma, something that no amount of advertising dollars can buy. And if no one wins, they don't have to pay much of anything. Don't underestimate the value of those -50 evil points.
Doing it for something on the order of $30 million is an achievement, same as the Ansari X-Prize wasn't about doing something new, but doing it for cheap without government involvement.
Given the investments of participants from the last one, where Scaled Composites spent $20 Million for a $10 Million prize, I'd expect that if someone does this, it will be for less than $100 million. I would guess that to be able to get a capable robot to the moon would require a launch vehicle on the order of the Falcon 9, which is a priced from $35-$55 million per launch. I haven't done the numbers for the mass fraction (fuel to payload ratio) from LEO or GTO to the moon, so I can't say what the mass of the required robot would be, or even given that, what the launch weight (and therefore costs) would be.
But, still, given launch costs, unless they somehow manage to figure out something that SpaceX and Rocketplane-Kistler haven't, this prize is either just about right, or too little. Certainly not too much. I'm pretty optimistic about it right now, and hope we hear some things about it soon.
There are two reasons to make a really big telescope (whether optical, radio, or even x-ray). FIrst you pick up more photons, allowing you to pick up dimmer, more distant objects and get less noisy data. The second is that you get improved angular resolution, since the limiting factor for resolution on a good telescope is the diffraction of light, a consequence of the wave nature. Simply, the angular resolution is approximated very well by Rayleigh's Formula:
Resolution(radians) = Wavelength/Diameter
When you do this kind of technique, you increase the angular resolution that can be picked up to that of a full telescope over the area (if designed properly to get the middle resolutions as well). However, as others have mentioned, you don't get the full number of photons, which means you have to increase the imaging time or allow for much high SNRs. However, this is still very useful for getting high resolution images of fairly bright objects.
It's an interesting idea, but its a difficult task because relative positions have to be maintained within fractions of wavelengths, so centimeters or millimeters for radio waves. While not technically impossible, doing this over the size of the Earth's orbit is a very difficult engineering task, requiring new tracking technologies and huge amounts of station-keeping fuel and precision.
So at this point, possible but expensive. I could see it as a 50-year-out kind of technology, unless someone decides it really needs to be done soon, and has the influence and money to back it up.
Just to expand on this comment for other readers, any time you do this with any kind of wavelength, you have to have the positions of the telescopes known within fractions of a wavelength. Radio waves range from meters to millimeters, so precision on a worldwide scale is difficult but not impossible at this range , although doing it in real-time is still an impressive feat, as this used to be done by recording the signals to tape, taking them to a central location and processing the data then.
However, expanding it to optical frequencies (where you can pick up different types of objects and also do so to much higher resolution) is difficult, since the wavelengths are around 500 nanometers, a level of precision that is still impossible on worldwide scales, except maybe in space, where you can depend on laser range finding over very long distances, although i don't know of any proposals trying to do this over very large scale.
Well, as long as we're being pedantic, solar wind actually causes a periodic change in altitude, since its being sped up while moving away from the sun, and slowed down when approaching it. Intuition tells me this orbit is slightly egg-shaped (not elliptical, but varying the second focus of the ellipse as it moves).
I'll concede you the density out there isn't quite zero, so you get some eventual decay... I have no idea what the time frame on that is though.
Just to be clear, a GEO satellite doesn't really decay. It will fluctuate and perturb, yes; the N-S drift due to the Sun and Moon are particularly annoying. However, it won't lose altitude like a LEO satellite will since there is no atmosphere at all, not even the very sparse atmosphere that slows down those spacecraft.
Because it allows us to continue to use our MythTV systems without having to rely on screen-scraping.
You may like TiVo, it certainly looks nice, easy to use. But I enjoy having my Myth box because it can do so many more things, even if it is an order of magnitude more difficult to set up (but not necessarily to use). Same as I appreciate OS-X, but I think I'll stick with linux not for the price and commodity hardware, but for the customizability and the ability to tinker. Same reason as I bought my Buffalo router recently to reflash to Open-WRT, its harder but its interesting and inherently more powerful than the stock D-link I used before.
So, this isn't to try and start a conflict, just to explain that I enjoy my mythbox, and I appreciate a new service to keep it working well. You may enjoy your TiVo, as well you should, I just don't think its for me right now, and I'm sure others feel the same.
I think as a permanent price point, $15 for three months is marginal. However, if they keep to their goal of reducing the costs to $20/year, it's not so bad.
I'm pretty sure I'll buy this service, partially because I'd like to avoid the hassles and problems of screen scraping, and partially because I'd like to support this project as I really appreciate them coming up with a solution, even if its not quite as ideal as before.
Anyway, its still 3x cheaper than TiVo.
The difference is is that they're operating by brute force, pushing the object way out of the way. But, a more nuanced subtle approach, characterizing NEO's orbits more and more accurately if they seem to be a threat, and making these small course corrections seems to be a much more responsible approach. I guess its good to have the nuke option on the table if a big one comes out of nowhere with less than a years warning time, or something like that; I guess a long-period object has the potential to do that and be missed until too late.