Er, SSO is LEO. According to Wikipedia, SSO is usually at an altitude of 600-800km, and LEO is defined as any orbit between 160km and 2000km. ISS is only at an altitude of 350 km. If you're in any kind of stable orbit (i.e. above the atmosphere), you're in LEO or higher.
Also, considering the size of a Cubesat (1 kg, 0.1 cubic meter), you could launch several hundred on any launch vehicle.
Yeah, the satellite size ranges are really messed up. Consider that a normal satellite weighs on the order of a metric ton or several tons (1000's of kgs). For some reason, the names only scale as a factor of 10, not 1000, so micro-sats are around 100 kg, nano-sats around 10 kg, and picosats around 1 kg. There are actually femto-sats (if I recall correctly), that are little more than a small circuit board with a few chips on it. Those are 100's of grams. There's also mini-sats somewhere between full satellites and micro-sats, but I don't know where they're supposed to fit in.
Not enough thrust, mainly. You could get there with a lot less fuel, but it would take a very long time. Even with a direct-launch rocket, they're looking at 6 months (I think). So they'd be great for getting supplies to Mars, because you'd be able to send a ton of stuff, and it wouldn't matter so much that it took a long time (so long as you have a steady chain). But for people, it would be a very long and boring trip (as if 6 months isn't bad enough!).
There may have been some backlash against the nuclear reactor too- I'm not sure about that. It's funny, because those programs came about because when Bush got into office he allowed for the possibility, then a few years later essentially killed them by mandating that most NASA money had to go towards getting a man to Mars.
The T5 is hardly a new thruster- it's probably been around for 10 years or more. And it's not that impressive in terms of performance for an ion thruster. More impressive ion thrusters exist, like the NSTAR thruster they used on Deep Space 1. That provided main propulsion and lasted way longer than expected, so DS1 got a lot done. Or look at the nuclear-reactor powered ion thrusters that were under development until Bush decided we were going to Mars (NEXUS and HiPEP).
Ion thrusters (and electric propulsion) have been around since the 60s. Back then, they used mercury for propellant and they had grid voltages of 13kV. Tons of ion thrusters have flown already and are already doing stationkeeping on satellites right now.
It is expensive, but it has great performance compared to almost all other materials (the one better is mercury...). Sure, you can use other materials, but the efficiency drops like a rock. I think the use of Krypton or Argon is being looked at for some thrusters (maybe not ion thrusters).
Oh, and ion thrusters have been around since the 60's, and Hall thrusters before that (made by the Russians). They've flown on a lot of missions already- this one isn't at all remarkable to be honest. Deep Space 1 was a lot more impressive.
No, mass is important. The fact that xenon is so massive is exactly why it's used- that and the fact that it has a very low ionization potential. The only better material is mercury, but they stopped using that several years ago for obvious reasons.
I don't think it's accurate to call the equation bunk. The numbers we can put into it surely are, but the equation itself is probably more or less fine. If you knew all those probabilities exactly, you'd get the right answer. The question is whether we know those numbers or not. And I think the argument is that if even if you make those numbers tremendously small, N is so large (especially if you include the universe, not just the Milky Way), that the odds of life elsewhere in the universe are enormous.
The article you linked to seemed to be more interested in debunking communication with alien life, which I'm sure is a quite reasonable thing to do. There's no suggestion that we're anywhere near another planet with life on it. But at least one does exist someone, and there's probably a lot more than that.
I'm reading Bill Bryson's Short History of Nearly Everything at the moment, and early on he quotes a particular scientist who has run those odds in several different ways, but always comes back to there being life on a huge number of planets in the universe. Remember, the odds are certainly long, but we can't even come close to wrapping our minds around just how big this place is.
Depending on the parallel efficiency of the program, in general it should be more efficient to use up as much of the processor as possible. If you have 4 processors and are only running one program, then that program should use up all four. If you only program for single threads, then the code is less optimized generally speaking.
I would suppose that more advanced codes should be able to parallelize when there are open CPUs and use a single thread when the system is loaded down (assuming that a single thread is more efficient). Not having parallelization hobbles a program running on a multiple processor system.
I'm guessing it has a lot more to do with Windows being pre-installed on everyone's computer. Once it's there and average joe is used to it, he's not going to bother changing to something else. There's no estimation of value, explicit or implicit there.
And honestly, Linux would "cost" the average person more than $300 to start using in terms of time and effort. It's cost me way more than that, and I have some idea of what I'm doing.
You have no idea what the distribution of cut rates is so there is no way to make an assumption of standard deviation. The average could be three because it's 0 in one 12 day period and 6 in another. Also consider that there are over 52 12 day periods per year, multiplied by the number of years, etc.
The odds of hitting a royal flush are tiny, but that doesn't mean it never happens. Statistics are not truth.
Sorry, but everything works that way (unless maybe if you're near the speed of light). I don't care how you do it, but if you shoot something one way, there is an equal and opposite force the other way. Obviously in this case the ship won't notice, but if the rail gun wasn't bolted down I bet it would jump pretty good.
Airport security doesn't get paid well and is an unpleasant job to boot. Therefore, anyone who can get a better job at the same pay will do so. If they can't get a better job, they probably didn't go to college. Obviously, there are many reasons not to go to college, but if you don't you probably weren't valedictorian in high school. Therefore, it is reasonable to assume that airport security is not in general composed of well-educated people. I wasn't making a generalization, I was making a reasoned assumption.
So, no positive replies to this at all? When it's trying to do the same thing that has been most successful in other countries? It's a much better idea than relying on random searches and X-ray machines. The machines are easy to confuse and to avoid a random search all you have to do is look white and Christian. At least this way there is some hope that you can detect anyone that is a possible threat.
That said, I'm sure the underpaid screeners will do a crappy job. If you're working airport security in the US, you're probably not very bright. And I'm not one of the people who is terribly afraid of a terrorist attack (especially on an airplane) either. But if they're going to pull some percentage of travelers out of line for secondary screening, it would be nice if they had a reason other than skin color or religious dress. I've certainly never seen someone in full Muslim attire make it through security without being pulled aside.
A lot of games, including RPGs, have a New Game+ feature where you can restart with various bonuses (all your items, levels, power-ups, etc.). Examples off the top of my head: Chrono Trigger, Final Fantasy X-2, Vagrant Story, Okami, Shadow of the Colossus. And most of those have stackable benefits. So I would be pretty distraught if I lost my Vagrant Story save with all Damascus Armor and multiple Rhomphaias (who remembers any of this?), or my original Chrono Trigger save (I mean ORIGINAL) with most character stats maxed out after tens of playthroughs.
I have both the DexDrive for PSX and Sharkport for PS2, and I've made use of both. To be honest, I've probably used them more as a way to hold onto old saves when I need more room on my memory card than anything, especially with the old PSX 15 slot cards. It's nice for silly things like having saves right before all of the major FMVs in FF8. Of course, there's no backing up my old SNES games, so if that battery ever dies in my Chrono Trigger cart, I'm screwed.
I remember Lewis Black's segment on GTA- it's the reason I ever even gave the game a shot. Then, after playing for five hours straight, I decided it was probably a decent game...
Consoles have a horrible interface when compared to PCs Right, because everyone loves controlling a game with a keyboard, especially when you need a template to figure out what all the keys do. Console controllers are comfortable and have as many buttons as any game should ever need, plus you get extra effects like rumble and motion sensing.
Can the US compete against two superpowers in an arms race? Well, since our military budget is more than that of all other countries combined, I'd have to say yes. Should we? No. But I'm sure we could (for at least a while).
Actually, I know exactly what I'm talking about. I have to deal with those restrictions myself- they directly affect the work I do. So I absolutely know what they mean. And I know for a fact that no technical information for anything that is planned to go into space can be released to a non-US entity (since 9/11). Broadly speaking, that includes any information that allows the device to be replicated- dimensions, detailed operation, schematics, etc. Although anything already in the public domain is OK.
I can guarantee no non-US agency or company will use DARPA's method any time soon. All space-related activity falls under International Traffic in Arms Regulations (ITAR), so it can't be shared with any non-US entity.
Slashdot Mirror
Er, SSO is LEO. According to Wikipedia, SSO is usually at an altitude of 600-800km, and LEO is defined as any orbit between 160km and 2000km. ISS is only at an altitude of 350 km. If you're in any kind of stable orbit (i.e. above the atmosphere), you're in LEO or higher.
Also, considering the size of a Cubesat (1 kg, 0.1 cubic meter), you could launch several hundred on any launch vehicle.
Yeah, the satellite size ranges are really messed up. Consider that a normal satellite weighs on the order of a metric ton or several tons (1000's of kgs). For some reason, the names only scale as a factor of 10, not 1000, so micro-sats are around 100 kg, nano-sats around 10 kg, and picosats around 1 kg. There are actually femto-sats (if I recall correctly), that are little more than a small circuit board with a few chips on it. Those are 100's of grams. There's also mini-sats somewhere between full satellites and micro-sats, but I don't know where they're supposed to fit in.
Not enough thrust, mainly. You could get there with a lot less fuel, but it would take a very long time. Even with a direct-launch rocket, they're looking at 6 months (I think). So they'd be great for getting supplies to Mars, because you'd be able to send a ton of stuff, and it wouldn't matter so much that it took a long time (so long as you have a steady chain). But for people, it would be a very long and boring trip (as if 6 months isn't bad enough!).
There may have been some backlash against the nuclear reactor too- I'm not sure about that. It's funny, because those programs came about because when Bush got into office he allowed for the possibility, then a few years later essentially killed them by mandating that most NASA money had to go towards getting a man to Mars.
The T5 is hardly a new thruster- it's probably been around for 10 years or more. And it's not that impressive in terms of performance for an ion thruster. More impressive ion thrusters exist, like the NSTAR thruster they used on Deep Space 1. That provided main propulsion and lasted way longer than expected, so DS1 got a lot done. Or look at the nuclear-reactor powered ion thrusters that were under development until Bush decided we were going to Mars (NEXUS and HiPEP).
Ion thrusters (and electric propulsion) have been around since the 60s. Back then, they used mercury for propellant and they had grid voltages of 13kV. Tons of ion thrusters have flown already and are already doing stationkeeping on satellites right now.
Since these thrusters only operate in a vacuum, I'm afraid they don't make any sound at all...
It is expensive, but it has great performance compared to almost all other materials (the one better is mercury...). Sure, you can use other materials, but the efficiency drops like a rock. I think the use of Krypton or Argon is being looked at for some thrusters (maybe not ion thrusters). Oh, and ion thrusters have been around since the 60's, and Hall thrusters before that (made by the Russians). They've flown on a lot of missions already- this one isn't at all remarkable to be honest. Deep Space 1 was a lot more impressive.
No, mass is important. The fact that xenon is so massive is exactly why it's used- that and the fact that it has a very low ionization potential. The only better material is mercury, but they stopped using that several years ago for obvious reasons.
Note that POS in this context means "Point of Sale", not "Piece of Sh*t".
I don't think it's accurate to call the equation bunk. The numbers we can put into it surely are, but the equation itself is probably more or less fine. If you knew all those probabilities exactly, you'd get the right answer. The question is whether we know those numbers or not. And I think the argument is that if even if you make those numbers tremendously small, N is so large (especially if you include the universe, not just the Milky Way), that the odds of life elsewhere in the universe are enormous. The article you linked to seemed to be more interested in debunking communication with alien life, which I'm sure is a quite reasonable thing to do. There's no suggestion that we're anywhere near another planet with life on it. But at least one does exist someone, and there's probably a lot more than that.
I'm reading Bill Bryson's Short History of Nearly Everything at the moment, and early on he quotes a particular scientist who has run those odds in several different ways, but always comes back to there being life on a huge number of planets in the universe. Remember, the odds are certainly long, but we can't even come close to wrapping our minds around just how big this place is.
Depending on the parallel efficiency of the program, in general it should be more efficient to use up as much of the processor as possible. If you have 4 processors and are only running one program, then that program should use up all four. If you only program for single threads, then the code is less optimized generally speaking. I would suppose that more advanced codes should be able to parallelize when there are open CPUs and use a single thread when the system is loaded down (assuming that a single thread is more efficient). Not having parallelization hobbles a program running on a multiple processor system.
I'm guessing it has a lot more to do with Windows being pre-installed on everyone's computer. Once it's there and average joe is used to it, he's not going to bother changing to something else. There's no estimation of value, explicit or implicit there. And honestly, Linux would "cost" the average person more than $300 to start using in terms of time and effort. It's cost me way more than that, and I have some idea of what I'm doing.
You have no idea what the distribution of cut rates is so there is no way to make an assumption of standard deviation. The average could be three because it's 0 in one 12 day period and 6 in another. Also consider that there are over 52 12 day periods per year, multiplied by the number of years, etc. The odds of hitting a royal flush are tiny, but that doesn't mean it never happens. Statistics are not truth.
Sorry, but everything works that way (unless maybe if you're near the speed of light). I don't care how you do it, but if you shoot something one way, there is an equal and opposite force the other way. Obviously in this case the ship won't notice, but if the rail gun wasn't bolted down I bet it would jump pretty good.
Nah, just change your name to something German-sounding.
Airport security doesn't get paid well and is an unpleasant job to boot. Therefore, anyone who can get a better job at the same pay will do so. If they can't get a better job, they probably didn't go to college. Obviously, there are many reasons not to go to college, but if you don't you probably weren't valedictorian in high school. Therefore, it is reasonable to assume that airport security is not in general composed of well-educated people. I wasn't making a generalization, I was making a reasoned assumption.
So, no positive replies to this at all? When it's trying to do the same thing that has been most successful in other countries? It's a much better idea than relying on random searches and X-ray machines. The machines are easy to confuse and to avoid a random search all you have to do is look white and Christian. At least this way there is some hope that you can detect anyone that is a possible threat. That said, I'm sure the underpaid screeners will do a crappy job. If you're working airport security in the US, you're probably not very bright. And I'm not one of the people who is terribly afraid of a terrorist attack (especially on an airplane) either. But if they're going to pull some percentage of travelers out of line for secondary screening, it would be nice if they had a reason other than skin color or religious dress. I've certainly never seen someone in full Muslim attire make it through security without being pulled aside.
A lot of games, including RPGs, have a New Game+ feature where you can restart with various bonuses (all your items, levels, power-ups, etc.). Examples off the top of my head: Chrono Trigger, Final Fantasy X-2, Vagrant Story, Okami, Shadow of the Colossus. And most of those have stackable benefits. So I would be pretty distraught if I lost my Vagrant Story save with all Damascus Armor and multiple Rhomphaias (who remembers any of this?), or my original Chrono Trigger save (I mean ORIGINAL) with most character stats maxed out after tens of playthroughs.
I have both the DexDrive for PSX and Sharkport for PS2, and I've made use of both. To be honest, I've probably used them more as a way to hold onto old saves when I need more room on my memory card than anything, especially with the old PSX 15 slot cards. It's nice for silly things like having saves right before all of the major FMVs in FF8. Of course, there's no backing up my old SNES games, so if that battery ever dies in my Chrono Trigger cart, I'm screwed.
The good news is that he did grow into it.
I remember Lewis Black's segment on GTA- it's the reason I ever even gave the game a shot. Then, after playing for five hours straight, I decided it was probably a decent game...
Anyone want to wager on who has this hole fixed first, IE or Firefox?
Can the US compete against two superpowers in an arms race? Well, since our military budget is more than that of all other countries combined, I'd have to say yes. Should we? No. But I'm sure we could (for at least a while).
Actually, I know exactly what I'm talking about. I have to deal with those restrictions myself- they directly affect the work I do. So I absolutely know what they mean. And I know for a fact that no technical information for anything that is planned to go into space can be released to a non-US entity (since 9/11). Broadly speaking, that includes any information that allows the device to be replicated- dimensions, detailed operation, schematics, etc. Although anything already in the public domain is OK.
I can guarantee no non-US agency or company will use DARPA's method any time soon. All space-related activity falls under International Traffic in Arms Regulations (ITAR), so it can't be shared with any non-US entity.