Thanks for trying. Edison was an amazing little chunk of hardware for certain purposes (mine was low-power systems that interfaced to things with proprietary x86 drivers), but it always felt like it was one hardware guy's pet project that nobody in the software department gave half a rotten rat's ass about.
The crap they had instead of tech support was a legendary middle finger to the customers. A bunch of clueless, barely-English-literate drones who did nothing but reply to your post about something wrong the docs by telling you where you can download those same docs, or with "We are aware of that issue. There is no ETA for a fix."
The part I could never understand was their compulsion to mangle and mutilate a 500 MHz, 64 bit, dual core PC until it looked like an 8 bit, 16 MHz microcontroller's retarded cousin. I'm guessing it had something to do with layer upon layer of misunderstanding management, but it must have taken a monumental tower of pointy hair to create that clusterfuck.
I'd be curious to hear about the internal mismanagement that led to the utter failure of the products, if such things may or may not be able to leak out.
Reporters at the BBC discovered today that reporting on scientific experiments without basic background knowledge can result in wildly inaccurate headlines. The reporters' usual technique of absentmindedly skimming someone else's account of an event, copying a few juicy-sounding words, and filling in the rest with fluff turned out to completely misrepresent the actual science.
When asked for comment, a BBC spokesman said, "Piss off, egghead. You clicked on it, didn't you? Mission fucking accomplished on our end."
Yeeeaaahh, you don't have optimal conditions 24/7/365. Solar panels produce, on average, something like 20% of their rated capacity. So turn that 17 years into 85 years, and that's before you account for the fact that the supplier's wholesale price for electricity is less than half of the $0.12/kWh that the end customer pays.
When the propellants are two reactive liquids that ignite on contact with each other, a kaboom is a perfectly reasonable consequence of a sudden, severe rearrangement of the tankage.
Back when Edison hit the market, I got seriously excited and started developing things that weren't possible without the CPU muscle and low power consumption that it offers. Then I ran into the sucking quagmire that is Intel's software support.
Broken drivers. Broken build environments. Undocumented pin muxing. Undocumented power management. Undocumented everything. Proprietary, unavailable tools needed to reconfigure things. They took a half-finished, 30% functional board support package, excreted it upon the world, and hoped that Open Source Magic meant that everyone else would fix their shit. Nearly three years later, almost nothing has been fixed and the product (whose hardware is still unmatched for power efficiency among hacker SBCs) is effectively dead.
I won't put any confidence at all in Joule until I see the kind of hardware documentation and software support that an embedded system needs to actually be, y'know, embedded into things.
While it's hard to tell how fast it's actually spinning because they keep messing with the playback speed, most payloads don't want to operate while spinning as fast as is required for stabilizing the rocket. They generally use yo-yo de-spin or RCS to reduce the roll rate.
A -453F reading, unless you went to great cryogenic pains, means your temperature gauge is either broken or being used under conditions where it doesn't work. The atmosphere never gets below about -130F, and by the time it gets that cold, it's so thin that it has very little impact on the temperature of big solid objects. At that point, objects interact thermally with the outside world entirely by radiation, which is a very slow way to reach low temperatures. Not to mention the flight was in sunlight and had a warm Earth occupying almost a hemisphere of the view, which would keep things nice and warm.
So what are the implications for reactor design, physicists?
Probably not much. There's so much empirical data about the behavior of fission in reactor-like conditions that, even without a deep understanding of why things happen that way, we pretty much know what happens. That's almost certainly why they simulated the reaction they did -- we have tons of data about it already, so you can tell if the model's good.
Some slight refinements might show up eventually, but the impact of a model like this on reactors will be small.
Most nuclear physicists aren't researching fission reactors, though. The ones pushing the boundaries of the field, coaxing colliders into producing heavier nuclei, investigating weird excited states, and such, are the ones who will really notice this.
"Build yourself a power plant?" "Give my daughter a job?" You've got to remember that these are just simple Southerners. These are people of Fox News. The common clay of the new America. You know... Morons.
Option 1 would be consistent with much of my previous experience, if you change out "morons who also don't know" for "enthusiastically naive people who don't pause to consider." "Design" projects emphasize concepts and pretty pictures over execution, cost effectiveness, and practicality, and many of the most severely hyped ideas from that community run the gamut of unworkability from "merely completely impractical" to "would need to reverse basic physics."
Apparently the industrial design curriculum doesn't cover thermodynamics. Condensing water at room temperature requires shedding about 680 watt-hours of energy per liter, and thermoelectric coolers tend to burn off more than twice the energy they pump (depends on a few variables, but practical devices in practical situations usually fall in that ballpark). You'd need somewhere near a constant half-kilowatt to provide for one person's normal water consumption. Much more if they're exercising or in a hot environment.
If you blow a grand on flying just a camera and tracker, you're doing something amazingly wrong. I worked on a university project that didn't cost that much, and we flew two expensive radios, a SPOT tracker, APRS tracker, Arduino Due flight computer, HD video camera, two GPS receivers, an active thermal control system, and a Kerbal, and we went into it not really knowing what the hell we were doing.
With one flight's worth of experience under my belt, I could put together a decent tracked payload with sensors and a camera for under $200, using off-the-shelf components. Less if I want to spend time making a circuit board. I'm not sure what helium costs these days, but that and a small envelope sure as hell aren't going to add $800 to the bill.
There's another possibility that occurred to me: That the actual mission concept does incorporate measures to address those problems, including propulsion on the chipsats, but was so magnificently mangled by the press office and reporters as to create the appearance of complete crackheadedness. This would require a slightly greater-than-usual commitment to misrepresentation and intellectual laziness on the part of the journalism majors, but is within the realm of plausibility.
Trust me, no scientist at Draper spent months on this. It would make some damn sense if they had. It reads like a summer intern's wide-eyed ramblings after they just read about things other cubesats have done, but before they considered any of the actual engineering issues.
And sometimes, you end up with a random/.er who, though the satellite he's working on is only going to low Earth orbit, sees the potential of applying the cubesat fast/cheap/high-risk philosophy to interplanetary missions, had already quantified the problems with power generation at Jovian distances from the sun and the resources required to communicate with a miniscule power budget, and even went and read about the possibility of common materials surviving unshielded reentry a few years ago when the chipsat idea started making headlines.
There's real potential for using cubesats beyond Earth orbit. Lots and lots of people have noticed this, and they've generally also noticed the same set of problems -- power, cold, communication, and radiation. There are possible solutions to each of those, but they come with major costs and the probe described and drawn in the article incorporates none of them.
The aerodynamic entry idea is utter nonsense on that moon, though -- what passes for an atmosphere on Europa would qualify as "ultra-high vacuum" in a laboratory. It's about the same density as what the ISS is orbiting through right now. There is no structure in existence that could decelerate enough in that atmosphere to land gently. The terminal velocity of a flake of monolayer graphene is comparable to rifle muzzle velocities, and functional circuitry is a few orders of magnitude heavier than that.
Um, are we talking about the same Europa here? The one with the atmosphere that barely musters a nanotorr at the surface? The one where the terminal velocity of a scrap of mylar film is on the order of tens of kilometers per second? I think that "float down" plan may have been selected a bit hastily.
At least the chipsats turning into teeny little craters in the ice will reduce the data burden for the cubesat's transmitter, which based on those solar panels has a power budget of about a tenth of a watt to make a link at a range close to a billion kilometers. You can maybe squeeze a few hundred bits per second out of that while you're tying up a DSN dish, otherwise forget it.
Maybe they're thinking of making it an accessory to a full-size probe, but forgot to mention the need to send a few hundred kilograms of other stuff out there too. Or maybe somebody was behind on their press release quota, and this half-baked crap was the best thing they had lying around.
Since it's two or three orders of magnitude further away than traditional cubesat territory, i.e. low Earth orbit, and they're planning to use it as a proving ground for interplanetary cubesat technology.
That's not as big a problem as you'd think. In solution, you don't have molecules of NaCl; you have dissociated ions of Na+ and Cl-, each of which is surrounded by a cluster of rather tightly-bound water molecules. Those clusters are much larger than bare ions or single water molecules, so there's a fair range of pore sizes that will separate the ions from the water.
I think they're abusing the terminology a bit, using "RO" to refer to reverse osmosis conducted with existing membrane technologies. The point at issue is that thermodynamics demands that a certain amount of energy be expended in order to reduce the entropy of a homogeneous salt solution by separating it into pure (or at least low-salinity) water and high-salinity leftovers. This is totally independent of the means by which the molecules are separated. In reverse osmosis, that manifests as a minimum pressure necessary to force salt water through any selectively permeable membrane.
Practical RO systems operate with a pressure drop (and therefore energy consumption per unit volume) that's double or triple the osmotic pressure, in order to achieve useful flow rates across thick membranes with relatively low pore densities. A better filter would allow that excess pressure to be reduced, but can't do anything about the cost of reducing the entropy.
Slashdot Mirror
Thanks for trying. Edison was an amazing little chunk of hardware for certain purposes (mine was low-power systems that interfaced to things with proprietary x86 drivers), but it always felt like it was one hardware guy's pet project that nobody in the software department gave half a rotten rat's ass about.
The crap they had instead of tech support was a legendary middle finger to the customers. A bunch of clueless, barely-English-literate drones who did nothing but reply to your post about something wrong the docs by telling you where you can download those same docs, or with "We are aware of that issue. There is no ETA for a fix."
The part I could never understand was their compulsion to mangle and mutilate a 500 MHz, 64 bit, dual core PC until it looked like an 8 bit, 16 MHz microcontroller's retarded cousin. I'm guessing it had something to do with layer upon layer of misunderstanding management, but it must have taken a monumental tower of pointy hair to create that clusterfuck.
I'd be curious to hear about the internal mismanagement that led to the utter failure of the products, if such things may or may not be able to leak out.
No They Didn't, You Bloody Idiots
Reporters at the BBC discovered today that reporting on scientific experiments without basic background knowledge can result in wildly inaccurate headlines. The reporters' usual technique of absentmindedly skimming someone else's account of an event, copying a few juicy-sounding words, and filling in the rest with fluff turned out to completely misrepresent the actual science.
When asked for comment, a BBC spokesman said, "Piss off, egghead. You clicked on it, didn't you? Mission fucking accomplished on our end."
Yeeeaaahh, you don't have optimal conditions 24/7/365. Solar panels produce, on average, something like 20% of their rated capacity. So turn that 17 years into 85 years, and that's before you account for the fact that the supplier's wholesale price for electricity is less than half of the $0.12/kWh that the end customer pays.
When the propellants are two reactive liquids that ignite on contact with each other, a kaboom is a perfectly reasonable consequence of a sudden, severe rearrangement of the tankage.
Back when Edison hit the market, I got seriously excited and started developing things that weren't possible without the CPU muscle and low power consumption that it offers. Then I ran into the sucking quagmire that is Intel's software support.
Broken drivers. Broken build environments. Undocumented pin muxing. Undocumented power management. Undocumented everything. Proprietary, unavailable tools needed to reconfigure things. They took a half-finished, 30% functional board support package, excreted it upon the world, and hoped that Open Source Magic meant that everyone else would fix their shit. Nearly three years later, almost nothing has been fixed and the product (whose hardware is still unmatched for power efficiency among hacker SBCs) is effectively dead.
I won't put any confidence at all in Joule until I see the kind of hardware documentation and software support that an embedded system needs to actually be, y'know, embedded into things.
While it's hard to tell how fast it's actually spinning because they keep messing with the playback speed, most payloads don't want to operate while spinning as fast as is required for stabilizing the rocket. They generally use yo-yo de-spin or RCS to reduce the roll rate.
A -453F reading, unless you went to great cryogenic pains, means your temperature gauge is either broken or being used under conditions where it doesn't work. The atmosphere never gets below about -130F, and by the time it gets that cold, it's so thin that it has very little impact on the temperature of big solid objects. At that point, objects interact thermally with the outside world entirely by radiation, which is a very slow way to reach low temperatures. Not to mention the flight was in sunlight and had a warm Earth occupying almost a hemisphere of the view, which would keep things nice and warm.
Probably not much. There's so much empirical data about the behavior of fission in reactor-like conditions that, even without a deep understanding of why things happen that way, we pretty much know what happens. That's almost certainly why they simulated the reaction they did -- we have tons of data about it already, so you can tell if the model's good.
Some slight refinements might show up eventually, but the impact of a model like this on reactors will be small.
Most nuclear physicists aren't researching fission reactors, though. The ones pushing the boundaries of the field, coaxing colliders into producing heavier nuclei, investigating weird excited states, and such, are the ones who will really notice this.
It's been 25 years. I can do this for another 25.
Arlo Guthrie would be proud.
"Performant" is an invaluable word. It instantly identifies those who use it seriously as people who may be safely ignored.
"Build yourself a power plant?" "Give my daughter a job?" You've got to remember that these are just simple Southerners. These are people of Fox News. The common clay of the new America. You know... Morons.
Option 1 would be consistent with much of my previous experience, if you change out "morons who also don't know" for "enthusiastically naive people who don't pause to consider." "Design" projects emphasize concepts and pretty pictures over execution, cost effectiveness, and practicality, and many of the most severely hyped ideas from that community run the gamut of unworkability from "merely completely impractical" to "would need to reverse basic physics."
Apparently the industrial design curriculum doesn't cover thermodynamics. Condensing water at room temperature requires shedding about 680 watt-hours of energy per liter, and thermoelectric coolers tend to burn off more than twice the energy they pump (depends on a few variables, but practical devices in practical situations usually fall in that ballpark). You'd need somewhere near a constant half-kilowatt to provide for one person's normal water consumption. Much more if they're exercising or in a hot environment.
If you blow a grand on flying just a camera and tracker, you're doing something amazingly wrong. I worked on a university project that didn't cost that much, and we flew two expensive radios, a SPOT tracker, APRS tracker, Arduino Due flight computer, HD video camera, two GPS receivers, an active thermal control system, and a Kerbal, and we went into it not really knowing what the hell we were doing.
With one flight's worth of experience under my belt, I could put together a decent tracked payload with sensors and a camera for under $200, using off-the-shelf components. Less if I want to spend time making a circuit board. I'm not sure what helium costs these days, but that and a small envelope sure as hell aren't going to add $800 to the bill.
Yeah, but biofeedback also used to enjoy Mitch Hedberg.
Lisa, I want to buy your rock.
They do know that solar storms can do absolutely nothing to a data center but maybe cause power outages, right?
Do the writers completely ignore you? Do the set dressers intentionally screw up your whiteboards? Or do you just suck at every part of this job?
Or does anybody else feel like the summary came straight from the Simple English Wikipedia?
There's another possibility that occurred to me: That the actual mission concept does incorporate measures to address those problems, including propulsion on the chipsats, but was so magnificently mangled by the press office and reporters as to create the appearance of complete crackheadedness. This would require a slightly greater-than-usual commitment to misrepresentation and intellectual laziness on the part of the journalism majors, but is within the realm of plausibility.
Trust me, no scientist at Draper spent months on this. It would make some damn sense if they had. It reads like a summer intern's wide-eyed ramblings after they just read about things other cubesats have done, but before they considered any of the actual engineering issues.
/.er who, though the satellite he's working on is only going to low Earth orbit, sees the potential of applying the cubesat fast/cheap/high-risk philosophy to interplanetary missions, had already quantified the problems with power generation at Jovian distances from the sun and the resources required to communicate with a miniscule power budget, and even went and read about the possibility of common materials surviving unshielded reentry a few years ago when the chipsat idea started making headlines.
And sometimes, you end up with a random
There's real potential for using cubesats beyond Earth orbit. Lots and lots of people have noticed this, and they've generally also noticed the same set of problems -- power, cold, communication, and radiation. There are possible solutions to each of those, but they come with major costs and the probe described and drawn in the article incorporates none of them.
The aerodynamic entry idea is utter nonsense on that moon, though -- what passes for an atmosphere on Europa would qualify as "ultra-high vacuum" in a laboratory. It's about the same density as what the ISS is orbiting through right now. There is no structure in existence that could decelerate enough in that atmosphere to land gently. The terminal velocity of a flake of monolayer graphene is comparable to rifle muzzle velocities, and functional circuitry is a few orders of magnitude heavier than that.
Um, are we talking about the same Europa here? The one with the atmosphere that barely musters a nanotorr at the surface? The one where the terminal velocity of a scrap of mylar film is on the order of tens of kilometers per second? I think that "float down" plan may have been selected a bit hastily.
At least the chipsats turning into teeny little craters in the ice will reduce the data burden for the cubesat's transmitter, which based on those solar panels has a power budget of about a tenth of a watt to make a link at a range close to a billion kilometers. You can maybe squeeze a few hundred bits per second out of that while you're tying up a DSN dish, otherwise forget it.
Maybe they're thinking of making it an accessory to a full-size probe, but forgot to mention the need to send a few hundred kilograms of other stuff out there too. Or maybe somebody was behind on their press release quota, and this half-baked crap was the best thing they had lying around.
Since it's two or three orders of magnitude further away than traditional cubesat territory, i.e. low Earth orbit, and they're planning to use it as a proving ground for interplanetary cubesat technology.
That's not as big a problem as you'd think. In solution, you don't have molecules of NaCl; you have dissociated ions of Na+ and Cl-, each of which is surrounded by a cluster of rather tightly-bound water molecules. Those clusters are much larger than bare ions or single water molecules, so there's a fair range of pore sizes that will separate the ions from the water.
I think they're abusing the terminology a bit, using "RO" to refer to reverse osmosis conducted with existing membrane technologies. The point at issue is that thermodynamics demands that a certain amount of energy be expended in order to reduce the entropy of a homogeneous salt solution by separating it into pure (or at least low-salinity) water and high-salinity leftovers. This is totally independent of the means by which the molecules are separated. In reverse osmosis, that manifests as a minimum pressure necessary to force salt water through any selectively permeable membrane.
Practical RO systems operate with a pressure drop (and therefore energy consumption per unit volume) that's double or triple the osmotic pressure, in order to achieve useful flow rates across thick membranes with relatively low pore densities. A better filter would allow that excess pressure to be reduced, but can't do anything about the cost of reducing the entropy.