I take it you've never worked with SLA resins and parts then. Mass-produced plastic parts have varying degradation rates in the sun. Many have UV stabilizers in them that provide them with substantial life (many years) even in direct sunshine. SLA parts, in my experience, have a useful life measured in weeks if allowed to be in the sun. Even sitting around in an office environment, SLA parts will degrade over months.
So I wonder how this UV projector doesn't cause solids to form inside the vat if in fact this projector can cause plastic to solidify as it is being removed from the vat with liquid resin.
Or you could read the article to find out the answers to your questions.
Well, to quote the summary: "Ikea's introduction of wireless charging functionality on some of its new furniture heats up the battle for a global wireless charging standard"
Although you can get up into the 80% range (short distance between emitter and receiver, good axial alignment, well-tuned resonance frequencies, and proper shielding), you are more likely to be in the 50-75% efficiency range. That's for the inductive portion; there is also a loss in converting the 120/220V power from the wall. [I speak from professional experience developing a Qi-charged medical device. It was a good solution for the problem, as it allowed the case to be fully sealed, but turned me off the idea of using it for everything that needs charging.] For 5-10 W of actual charge power in the device, your losses from grid to device will be close to that amount This is about as bad as the 50-60 Hz wall wart transformers that we have recently gotten away from.
3D-printed metal has been used for quite a while in some of the lower-performance stages (lower pressure, lower temperature). Examples here. The key benefit is that they are able to integrate convoluted channels within the structure for cooling or mixing. You can also reduce weight by taking away significant internal volume, replacing it with ribs or a sparse matrix. I wouldn't go so far as to say that it's mainstream, but it's close.
The thing that stuck out in my mind would be time: depending on the size of the part and the quality, a #D-print build typically takes on the order of hours. Maybe that can get a bit better in time, but probably not by much. Given that, why put the fab in a truck?
Russia is doing all the taxi work — for a steep price
How much is it more expensive than private industry?
"Price" in this case may be an imprecise word. The monetary cost may not be all that bad compared to SpaceX or Boeing. (It may even be favorable, for all I know.) However, it does carry serious risk to have only one supplier that can get you to the ISS. Sometimes the public and private sector properly take the (potential) costs of risk into account. This is what the insurance industry does - putting a monetary cost (price) on risk. Other times people get blindsided by something that, in retrospect, they couldn't afford. Sometimes the risk is not quantifiable - can you put a price on the strategic risk of Russia getting one over on NASA (and, by extension, the USA)?
In other words: risk can be very, very expensive, whether it is included in a pricetag or not.
The industry term for the mixed, melted contents of a reactor core is "corium". It's a mix of fuel rod assemblies ( fuel and fission products, additives, moderators, salts, and cladding), fuel rods (zirconium), and containment vessel (stainless steel), all compounded with reactor water and whatever additives were in it. In a theoretical worst case, you get to add in some concrete from the floor of the reactor building, too.
In the article, their plan is have a large dorsal fin (the thing that looks like a vertically-oriented solar array in the artist's concept) which would be a phased array for direct transmission to Earth. To quote:
However, the direct transmission of worthwhile amounts of data over a billion miles to Earth requires a large antenna, implemented as a planar phased - array dorsal fin. (It was decided to simplify the mission to exclude a relay orbiter which would require significant propulsion and radioisotope power.) This antenna structure introduces a modest submerged drag penalty, as well as demanding judicious placement of large tanks for adequate buoyancy margin and surfaced stability.
I wondered about this as well: if you can create a gaseous or mixed-phase layer around the sub, you ought to be able to move through the liquid with reduced drag. You can't do this on Earth with something the size of a manned submersible - the necessary thermal flux would be insane - but I'm sure someone could make a PhD thesis out of modeling, then experimenting, with this in cryogenic liquids.
Damn, I just knew those NASA engineers were forgetting something!
Probably they would do it in a manner similar to how they do it with conventional submarines: occasionally surfacing and transmitting normally, or else releasing a buoy with communications capabilities.
Swagging it, 1.4 million implies at least 14 staff attorneys would have to work 12 months
At the least, I'd like to see a breakout of the labor estimates. It seems double to quadruple what I would expect.
You think the going rate for a staff attorney is $50/hour ($1.4mil, 14 persons, 2000 hrs/12 mo)? You haven't been around many attorneys, have you? The salary may work out to that (about $100k/yr), but with benefits and overhead, it could easily be double that. Just be lucky that an outside firm doesn't need to be involved - considering DC's rates, it could easily work out to $300/hr.
Another Antarctic balloon experiment, BLAST, was designed for re-usability. On its third flight, the parachute failed to properly detach, and ended up dragging the telescope for more than 100 miles across the ice, mostly destroying it.
This doesn't mean that one shouldn't try to recover and reuse experiments, but it does present new program-level risks.
The answer as to "why don't they?" could be as prosaic as: they didn't get funding for a multi-year, multi-launch program, or couldn't squeeze the reusability and refurbishment into their program budget.
(For those interested, that third mission was the subject of a neat documentary film.)
If there was any justice and sense to the English Language, "common sense" would be a curse word and shunned in polite conversation. Politicians, especially, have bastardized the use of the term for their own ends such that it hardly has any meaning aside from doublespeak.
I find this to be a fun game to play: anytime a politician starts talking about "common sense," replace it in your head with some sort of expletive. My preference is "Fucking Shite", as in
We need Fucking Shite solutions to our problems, not political speeches meant to ignite class warfare
I recall reading about the mirror when it was being made, the precision with which it was polished was mind bogglingly accurate
Be careful how you use the terms "precision" and "accuracy," because they have very specific meanings to engineers and metrologists. Yes, the precision was mind-boggling. The accuracy, on the other hand, well...
Despite the slight change in the curvature of the main mirror, Hubble's images were pretty amazing
Amazing maybe, but far below what was promised. There isn't any way to gloss over the fact that the project managed to screw up the single most important component in the telescope. The mirror ended flawed and in orbit not because it was too technically challenging, but because of arrogance, sloppiness, and poor oversight. The taxpayers have a right - even today - to be pretty steamed about it.
Imagine if someone sold you a sportscar, promising it would handle like a dream and hit 200 mph on the straightaway. When you finally receive it and test it out, it shimmies like a banshee and can only manage 100 mph. When you call to complain about it, you find out that during construction, the technicians got drunk one night, ground the cam shaft wrong, and left out one piston. The company sold it to you anyway, not because they were trying to cover anything up, but that they simply didn't know anything was wrong, because they'd never bothered to test drive it before shipping it. Your argument is that we should still have been happy to have it because it's better than the Honda Civic we were used to driving.
And, given the etymology of the word , "disaster" is a good choice.
A typical laptop battery maxes out at 100 Whr capacity. (Above 100 Whr gets problematic with shipping and air travel regulations.) So picture a stack of about 40 laptop battery packs - that's what Atlas' will be lugging around. In the videos, you can see a large briefcase-like box on the back.
Simply changing EPA rules by Presidential decree is dictatorial
The EPA is empowered, by Congress, to make such rules. The EPA falls under the executive branch, and so takes direction from the President, within the broad legislative mandate to protect the environment. In any event, the President hasn't actually issued new rules by decree - he's got certain goals, and has set the EPA to the task of actually drafting the rules and regulations through their normal process (which, for better or worse, includes lawsuits).
A President can't drop such regulations by decree, because that would violate the EPA's mandate and other existing laws enacted for the environment.
I did a bit of reading on the subject from TI, which has FRAM integrated into some of its MSP430 microcontrollers. If anything, the technology seems to be well-suited to the space environment, because bit storage is accomplished via a crystal structure change (polarization), rather than through charge storage.
That may be, but it wasn't exactly an option (in the sense of it being readily available and thoroughly tested for spaceflight) when the rovers were being designed 15 years ago. Is it even an option today?
I believe that there is one very high end 3D printer that has made metal weapons that work very well
That weapon was made using a DLMS (direct laser metal sintering) machine, which fuses metal powder using a powerful laser. This kind of machine goes for upwards of $1million, and isn't exactly turnkey. (I know: my company has one, and although it's amazing, it tends to not produce a usable copy of a new part until the 2nd of 3rd try.) Plus, it required a fair bit of post-machining.
Your example reinforces my point - if you want a "reliable and somewhat accurate weapon", you use metal, and metal rapid prototypers are not hobbyist equipment, and may not ever be. Plus, even if it were, you still need a reasonably well-equipped machine shop to finish the metal parts and assemble a working gun.
Slashdot Mirror
Don't look at the Laser Diode Arrays with remaining half of skull.
I take it you've never worked with SLA resins and parts then. Mass-produced plastic parts have varying degradation rates in the sun. Many have UV stabilizers in them that provide them with substantial life (many years) even in direct sunshine. SLA parts, in my experience, have a useful life measured in weeks if allowed to be in the sun. Even sitting around in an office environment, SLA parts will degrade over months.
Or you could read the article to find out the answers to your questions.
Well, to quote the summary: "Ikea's introduction of wireless charging functionality on some of its new furniture heats up the battle for a global wireless charging standard"
Although you can get up into the 80% range (short distance between emitter and receiver, good axial alignment, well-tuned resonance frequencies, and proper shielding), you are more likely to be in the 50-75% efficiency range. That's for the inductive portion; there is also a loss in converting the 120/220V power from the wall. [I speak from professional experience developing a Qi-charged medical device. It was a good solution for the problem, as it allowed the case to be fully sealed, but turned me off the idea of using it for everything that needs charging.] For 5-10 W of actual charge power in the device, your losses from grid to device will be close to that amount This is about as bad as the 50-60 Hz wall wart transformers that we have recently gotten away from.
3D-printed metal has been used for quite a while in some of the lower-performance stages (lower pressure, lower temperature). Examples here. The key benefit is that they are able to integrate convoluted channels within the structure for cooling or mixing. You can also reduce weight by taking away significant internal volume, replacing it with ribs or a sparse matrix. I wouldn't go so far as to say that it's mainstream, but it's close.
The thing that stuck out in my mind would be time: depending on the size of the part and the quality, a #D-print build typically takes on the order of hours. Maybe that can get a bit better in time, but probably not by much. Given that, why put the fab in a truck?
"Price" in this case may be an imprecise word. The monetary cost may not be all that bad compared to SpaceX or Boeing. (It may even be favorable, for all I know.) However, it does carry serious risk to have only one supplier that can get you to the ISS. Sometimes the public and private sector properly take the (potential) costs of risk into account. This is what the insurance industry does - putting a monetary cost (price) on risk. Other times people get blindsided by something that, in retrospect, they couldn't afford. Sometimes the risk is not quantifiable - can you put a price on the strategic risk of Russia getting one over on NASA (and, by extension, the USA)?
In other words: risk can be very, very expensive, whether it is included in a pricetag or not.
The industry term for the mixed, melted contents of a reactor core is "corium". It's a mix of fuel rod assemblies ( fuel and fission products, additives, moderators, salts, and cladding), fuel rods (zirconium), and containment vessel (stainless steel), all compounded with reactor water and whatever additives were in it. In a theoretical worst case, you get to add in some concrete from the floor of the reactor building, too.
In short, about half the periodic table.
I wondered about this as well: if you can create a gaseous or mixed-phase layer around the sub, you ought to be able to move through the liquid with reduced drag. You can't do this on Earth with something the size of a manned submersible - the necessary thermal flux would be insane - but I'm sure someone could make a PhD thesis out of modeling, then experimenting, with this in cryogenic liquids.
Damn, I just knew those NASA engineers were forgetting something!
Probably they would do it in a manner similar to how they do it with conventional submarines: occasionally surfacing and transmitting normally, or else releasing a buoy with communications capabilities.
You think the going rate for a staff attorney is $50/hour ($1.4mil, 14 persons, 2000 hrs/12 mo)? You haven't been around many attorneys, have you? The salary may work out to that (about $100k/yr), but with benefits and overhead, it could easily be double that. Just be lucky that an outside firm doesn't need to be involved - considering DC's rates, it could easily work out to $300/hr.
[turn snark amplifier up to 11...]
Yeah, well, freedom isn't free.
[dial snark amplifier back down to 5]
Another Antarctic balloon experiment, BLAST, was designed for re-usability. On its third flight, the parachute failed to properly detach, and ended up dragging the telescope for more than 100 miles across the ice, mostly destroying it.
This doesn't mean that one shouldn't try to recover and reuse experiments, but it does present new program-level risks.
The answer as to "why don't they?" could be as prosaic as: they didn't get funding for a multi-year, multi-launch program, or couldn't squeeze the reusability and refurbishment into their program budget.
(For those interested, that third mission was the subject of a neat documentary film.)
The ozone hole affects UV absorption. Spider operates in the microwave spectrum where ozone (or its absence) does not play a significant effect.
Water vapor plays a much, much greater role in those wavelengths, and the Antarctic atmosphere is about as good at it gets in that regard.
I find this to be a fun game to play: anytime a politician starts talking about "common sense," replace it in your head with some sort of expletive. My preference is "Fucking Shite", as in
-Rep Martha Roby, (R-AL)
This makes looking through a copy of Thomas Paine's pamphlet on the subject particularly amusing.
Be careful how you use the terms "precision" and "accuracy," because they have very specific meanings to engineers and metrologists. Yes, the precision was mind-boggling. The accuracy, on the other hand, well...
Amazing maybe, but far below what was promised. There isn't any way to gloss over the fact that the project managed to screw up the single most important component in the telescope. The mirror ended flawed and in orbit not because it was too technically challenging, but because of arrogance, sloppiness, and poor oversight. The taxpayers have a right - even today - to be pretty steamed about it.
Imagine if someone sold you a sportscar, promising it would handle like a dream and hit 200 mph on the straightaway. When you finally receive it and test it out, it shimmies like a banshee and can only manage 100 mph. When you call to complain about it, you find out that during construction, the technicians got drunk one night, ground the cam shaft wrong, and left out one piston. The company sold it to you anyway, not because they were trying to cover anything up, but that they simply didn't know anything was wrong, because they'd never bothered to test drive it before shipping it. Your argument is that we should still have been happy to have it because it's better than the Honda Civic we were used to driving. And, given the etymology of the word , "disaster" is a good choice.
Turn in your geek card. It actually goes...
God creates Dinosaurs
God destroys Dinosaurs
God creates Man
Man destroys God
Man creates Dinosaurs.
Dinosaurs eat Man, Woman inherits the Earth.
A typical laptop battery maxes out at 100 Whr capacity. (Above 100 Whr gets problematic with shipping and air travel regulations.) So picture a stack of about 40 laptop battery packs - that's what Atlas' will be lugging around. In the videos, you can see a large briefcase-like box on the back.
If the ISPs and telecoms are for it, then I'm against it.
Down with Net Neutrality! Damn them all to hell!
Wait, what were we talking about?
The EPA is empowered, by Congress, to make such rules. The EPA falls under the executive branch, and so takes direction from the President, within the broad legislative mandate to protect the environment. In any event, the President hasn't actually issued new rules by decree - he's got certain goals, and has set the EPA to the task of actually drafting the rules and regulations through their normal process (which, for better or worse, includes lawsuits).
A President can't drop such regulations by decree, because that would violate the EPA's mandate and other existing laws enacted for the environment.
I did a bit of reading on the subject from TI, which has FRAM integrated into some of its MSP430 microcontrollers. If anything, the technology seems to be well-suited to the space environment, because bit storage is accomplished via a crystal structure change (polarization), rather than through charge storage.
That may be, but it wasn't exactly an option (in the sense of it being readily available and thoroughly tested for spaceflight) when the rovers were being designed 15 years ago. Is it even an option today?
That weapon was made using a DLMS (direct laser metal sintering) machine, which fuses metal powder using a powerful laser. This kind of machine goes for upwards of $1million, and isn't exactly turnkey. (I know: my company has one, and although it's amazing, it tends to not produce a usable copy of a new part until the 2nd of 3rd try.) Plus, it required a fair bit of post-machining.
Your example reinforces my point - if you want a "reliable and somewhat accurate weapon", you use metal, and metal rapid prototypers are not hobbyist equipment, and may not ever be. Plus, even if it were, you still need a reasonably well-equipped machine shop to finish the metal parts and assemble a working gun.