Aka graphite oxide. It's made from graphite, and has been around for over a century. It's considered the most promising candidate for producing affordable graphene (most of the other techniques for making graphene do so in rather small volumes at rather high cost), but tends to produce the lowest quality graphene. So it's really promising to see that this is the raw material that the graphene electrode is sourced from.
What I find interesting is that the paper says that they used a "reduced graphene oxide electrode". Graphene oxide was first produced in 1859. It's a rather cheap, mass-produceable material, not at all exotic. However it was only first reduced to graphite in 2012 as it was difficult to find a pathway. It's seen as a promising route to cheap mass-produced graphene compared to other routes, with the downside that the resulting product is usually lower quality (although they've made lots of improvements in the past few years).
In case you didn't notice, batteries have dramatically increased in energy density over time. No, a cell phone is not entirely a battery, but battery sizes have shrunk in conjunction with phone sizes, even while their capacity (mAh) has been rising (significantly) over time.
People's inability to notice changing technology around them never ceases to amaze me. It's astounding how fast people get used to new technology and forget what old technology used to be like. It's like picking up an old video game that you played as a teenager and being shocked at how bad the graphics were.
Actually this is far better (from what I can see of it) than any of the previous work on li-air, which I've always taken a rather long view on. While it's really unfortunate I can't read the paper to see the exact details to get an idea of the manufacturing process and read more about the nature of the testing and the drawbacks mentioned, getting 93% efficiency and 2000 cycles on lithium-air are really staggering figures.
The only drawbacks the article mentions are "because the battery's ability to charge and discharge is too low." Soooooo... does that mean low power density? If so, to that I say so what? Today's li-ion cells have way more power density than is needed for propulsion, that's why you have things like Teslas beating supercars - their peak power is something like 20 times what they need to cruise at highway speeds. You could drop discharge power density by an order of magnitude and still have a fine car (optionally with a supercapacitor or small high power-density li-ion pack for bursts if desired) . And for recharge power density... when you have the absurd energy densities provided by li-air, it ceases to matter any more. Seriously, when you can drive all day on a single charge, who needs rapid chargers? You just plug in and charge while you sleep, so it makes no difference whether you can do it in 30 minutes or 8 hours. The top end of Level 2 charging should be enough to give a reasonably efficient vehicle a whole day's drive, no need for Level 3+.
I'd gladly take way lower power density in exchange for way higher energy density.
From the paper's abstract, I see that the chemicals involved in the battery are LiO2, graphene oxide, LiI and dimethoxyethane. LiO2 is cheap. Graphene oxides vary quite a bit depending on the preparation method, so it depends on what varient she's using, but most are cheap. Lithium iodide is cheap. Dimethoxyethane is cheap. Seriously, unless she's using an unusual rare/expensive form of graphene oxide, or is doing something weird and potentially costly in the manufacturing process, these should be affordable.
I really wish I could read more about the details, as that's where the devil lives, but... damned restricted access, yadda yadda yadda.:P
A drone might be harder to target than a medevac helicopter. It has no crew, only needing to carry the one patient, so it can automatically be much smaller and lighter, which means a smaller target and lower heat signature. And that's assuming it's still combustion-powered. An electric medevac drone would obviously have a much shorter range, but could still be useful to get people from a raid back to a FOB. Switching from ICE to electric would further reduce your heat signature 3-4 fold. It could (potentially) also be quieter.
Smaller could also potentially mean "portable". A team raiding a village could potentially bring one with them, leaving it ready to go on the outskirts. Which raises other possibilities: transporting people into raid areas (although you'd have little to no armour) or even transporting secured prisoners out.
While electric sucks in terms of range per kg, it excels in terms of power per kg. So if you're not trying to move people far...
Yeah - I think the concept of "dropping" munitions is thinking about it wrong. If you're dropping it, then it has to be a "smart munition" (wherein what's the point of a smart carrier?"), and if it's dumb, you're never going to hit by just dropping. And if you're not considering your craft expendible than you have to try to protect it, and you have to have the range to get back. Which rules out deploying your drones as effective "submunitions" of another delivery vehicle (drones dropped by plane, balloon or rocket technically don't even need motors, just control surfaces to control their glide to their targets)
"modified consumer drones" = cheap, but with camera and a degree of processing power = suicide seeker craft. Give it enough power to do basic image recognition, run it remotely until it gets (inevitably) jammed wherein it switches over to automated tracking and does its best to hit its target, in as rapid of a dive as it can manage. Plastic/composite = low radar cross signature. Small visibility cross section, and could be made out of clear plastic if desired. Low heat signature - on a glider, nearly none. You're talking something very hard to detect, and very hard to hit even if you detected it. And probably a lot cheaper than any countermeasure rocket you might try to launch at it. It doesn't take some massive weapon to take out an armoured vehicle - usually 1-4kg, depending on the warhead. So while we're not talking microdrones here, we're not talking about something huge either.
In a way, weapons are already moving in this direction. Look at the Javelin, for example. It doesn't just home in on a the center of some heat source - it uses multiple spectral frequencies and a 64x64 pixel sensor and processes the images with pattern-matching algorithms to aim for the place where the target will be located (not where it is), to avoid being tricked by decoys, and to pick the "sweet spot" on its target. It goes up - by rocket power, not prop power, but nonetheless - cruises laterally, then rapidly descends on its target. The operator doesn't need to be at the location of firing or continuously paint the target. Etc. It's a rocket, not a drone, but one can see the same strategy applied to drones. The main difference is that a rocket uses a big heavy, obvious thrust system to try to get to a target before it can get out of the way or hide, while a drone does its best to not be seen, taking its time until it finds a good opportunity and then striking.
Every piece of software contains at least one bug. Also, every piece of software code can be shortened. Therefore, every program can be shortened down to an empty source file which doesn't work.
Oh god, don't get me started on SLS. Have you seen the launch cost estimates? They're currently looking at $14k/kg to LEO not counting development costs, and assuming that you can manage to load the thing fully. Counting development, that depends on how many launches they make before they inevitably decide to cancel the way-too-expensive rocket. Most estimates I've seen so far put the development-included per-launch figure in the very rough ballpark of $40k/kg.
For people who know space, you already know that an "average" launch cost is $10k/kg to LEO. Russian and Chinese costs are usually around $7k/kg, sometimes cheaper. Falcon 9 is... if I recall correctly, about $5k/kg right now, maybe less. A rocket that costs $14k/kg, and that you have to lift something very heavy with every time, a billion dollars every time you fire the thing off... they might as well just paint the words "CANCEL ME" on the side.
Mars is far better mapped than the bottom of the oceans. Far, far better.
Lookup HiRISE for an example. It's on MRO which is in a low orbit around Mars, yet from Mars it was able to image Earth and the moon at 90 and 24 pixels across, respectively. It's taken pictures of 1% of Mars's surface at a resolution of *0,3 meters per pixel*. The highest resolution on Google Maps of Earth is 0,5 meters per pixel. I think the last full-planet coverage of Mars I saw was 3m/pixel, but it could be higher by now. Do you think we know the bottom of the oceans anywhere near that well?
"Trillion" is certainly a sizeable overestimate. But the Zubrinians (let alone the Mars One Nuts) are just in the opposite, far too optimistic in the other direction.
Everything else you wrote I entirely agree. I'd add that it's especially true when people try to push humans by arguing that "It's for Teh Science!" Because humans can do so much more, you see? Because they apparently have HiRISE imaging systems in their retinas and mass spectrometers in their palms and maybe a setup for X-ray fluorescence under their ears or something.
The reality is, science is done by... gasp...wait for it... scientific equipment. So of course you can send a human and have the human operate the scientific equipment, no question there. You could have a human orbiting Mars running HiRISE for example. But of the two things - the person and the telescope - which component is the one that's actually needed and which one is the remora hanging onto the side?
On the surface, yes, humans can reduce latency. To that I have to say:.............. and?.............. so?
What the heck does latency matter? We can only afford to launch a mission every few years. What does it matter if it takes the mission three days or three years to get its results? And no, humans aren't just going to "spot" neat things that a rover wouldn't - the rover's "eyes" are far better than the human's. And the rover operators control the rover to be just as "curious" as a human would be - moreso, really, because they have to long to plan every little tiny step. They launch whole investigations on what the ground looks like after the wheels kick it up or why the sand in one place slips a little bit more than in a place a couple dozen meters up the path.
The other one human spaceflight fans add is "repairing". Because, you see, failed Mars missions could have been saved by humans. SAVED! Except for, of course, manned spaceflight adds an order of magnitude more ways for the vehicle to fail. And most failures cannot be saved from. Seriously, check a list of how spacecraft en route to Mars have been lost. CATO launch failures. Failure to reach orbit. Failure to leave Earth orbit. Incorrect insertion trajectory calculations. Instability during reentry. Landing system hardware failures. And on and on. How is a human supposed to save these things? There's a few humans could have saved, but the large majority, no.
Humans eat up the vast majority of your payload. Without the remoras onboard and all of the associated systems for giving them a roomy, pressurized environment and keeping the chemical ratios therein balanced and shielding them from radiation and giving them water (heavy) and having water recycling systems and toilets and food stocks and carbon dioxide scrubbers and beds and exercise equipment and medical systems and let's not forget a whole habitat to live in when they get there, you'd have 1-2 orders of magnitude more payload return capability.
For all of the "benefits" of sending humans they want to raise the cost of a Mars mission by 1-2 orders of magnitude. For the same amount of money e could send dozens of diverse science missions to every corner of the planet containing every conceivable scientific payload and returning samples from bloody everywhere. Or we can send people to one place with a far smaller set of scientific equipment, because all of their budget was eaten up on the whole "keeping humans alive" thing.
It's really hard to extradite from the EU anyway even for non-politically-connected crimes. It took 8 years even to get Abu Hamza, which was about as open and shut as possible (including convictions in the UK) for about as hateable of a figure as possible for serious of crimes during a period where there was a major push to prosecute said crimes. The ECHR in particular is a major refuge for people arguing political prosecution. The right in many countries like the UK hates them, as they make it hard to prosecute many types of crime and force them to guarantee all sorts of rights for prisoners (like assisted reproductive services for sex offenders and such). In the case of Abu Hamza, they ruled that a variety of conditions in US prisons are "torture" and he couldn't be extradited until the US promised to make all sorts of restrictions on how he would be housed. They also had to agree to not seek the death penalty, and nearly required the US to not seek life in prison either. And if the US would ever break any of their promises, the ECHR would impose a general ban on extradition to the US (as they've done with many other countries), as it's against EU law to extradite to countries who do not have a track record of upholding their pledges concerning prisoners (it was imposed in the aftermath of the Agiza/Alzery case)
Now, this shouldn't be confused with moving people between EU states under the EAW process (surrender, not extradition), which is generally rather easy. EAWs bypass the executive branch entirely, and the automatic presumption is that the warrant is valid and should be enforced rather than the other way around.
Honestly, what would work out best for everyone would be if the US agreed to plea bargain with Snowden. He seems interested in it, the US would still send their message that "you can't run from the law forever", etc.
It's very common to own "summer homes" rather than land, although sometimes the summer homes come with land. My plan is actually to build a full-time single family house there (being a nerd, it'll be an underground steampunk cave house built supervillain-style into the side of my canyon;) And no, that's not common here;) ). Most people don't build full-time houses that far out unless they're farmers because they can't be bothered to have to drive half an hour to work. But lots of people drive 15-20 minutes to work, from Mosfellsbær or Hafnarfjörður to Reykjavík.
According to something I read on Slashdot, since then we've all become cows. Which would now that I think about it be pretty compelling evidence of rapid evolution.
Yes it is. It's data about where there is no data. Example:
Bob: I firmly believe there is rabid gorilla loose somewhere in this city.. Jane: I just searched my home. There's no evidence of a gorilla. Bob: The absence of evidence is not evidence of absence! Jane: I just searched 100 homes. Still no evidence of a gorilla. Bob: The absence of evidence is not evidence of absence! Jane: I just searched 10% of the town. Still no evidence of a gorilla. Bob: The absence of evidence is not evidence of absence! Jane: I just searched 95% of the town. Still no evidence of a gorilla. Bob: The absence of evidence is not evidence of absence!
Jane has a shortage of data about the presence of a gorilla. But the lack of finding data despite active search is itself very valuable data.
You're way south of us. That means far more light. In December/January, most days get no direct light at all, because while there's technically daylight, the sun is so low that almost anything can block it.
We're one of the windiest places on Earth. In the continental US, windspeeds like those found in Reykjavík (which peak BTW in late winter / early spring) are only found in the windiest parts of the Rockies and a couple other small isolated locales. Last winter there wasn't a single period that went more than three days without a windstorm, most very strong. One windstorm had 60m/s (130mph) winds at my land. Want to bike in that?
Our "winter", if you want to define it as the period in which you're likely to freeze your butt off , risk getting caught in a snowstorm, bike across ice, things of that nature, lasts for nearly half the year.
Riding a bike really only depends on the equipment you have. Buy the cloths to suit the activity.
Really? So what clothes suit 60 m/s winds while biking on a smooth sheet of ice?
I live in town but own land in the countryside (Hvalfjörður), about half an hour from downtown / 15 minutes from the outskirts (Mosó). Eventually I'll be moving out to my land, but not yet.
Yes, there is. They're the world's most competitive cyclists, racing at speeds about 3 times higher than your average transportation cyclist, and remember that air resistance is a function of velocity squared. The power they're capable of generating, for hours on end, is nearly an order of magnitude greater than a person who does not cycle regularly.
Which is why daily commuters don't eat a whole pig for dinner every night. But it's not as if you either need to eat an additional 5000 calories or there's no change whatsoever to your daily diet. Riding a bike at moderate speed burns about 40 calories per kilometer over one's baseline.
Aside from the fact that many people over-eat and thus need not consume any extra calories
Morbo Voice: "CALORIES DO NOT WORK THAT WAY!"
It's a very simple equation: calories in vs. calories out. Your body doesn't just toss away excess calories. Your body never excretes anything that it can just digest. The way your body changes the in/out balance is by varying your hunger level, which highly correlates with how much you eat. The only way to throw off the equation is by gaining or losing enough weight to have a practical effect on the baseline. But the baseline change with increasing or decreasing weight really isn't that significant. Your average person would have to lose 30-40 kilograms to make up for a short 7km-each-way bike commute. Do you really think commuting 7km to work on a bike is going to make your average person to lose 30-40 kilograms? Of course not. They might, might lose 5kg in an average case, 10 in a good case, maybe 15 in a really good case... and that only if you're not forcing them away from other exercise in order to do so.
The energy simply does NOT come from nothing. It comes from making you hungry and thus causing you to eat more to replace what you burned. If you disagree, you're in disagreement with medical science, and I don't suffer kooks.
food distribution is incredibly efficient,
1) The efficiency of food distribution is pathetic compared to the efficiency of oil distribution. When was the last time you saw a supertanker full of chicken wings unloading into a pipeline?
2) The energy required for distribution is built into the (very high) CO2 cost for producing food. Which is only one of food's numerous environmental problems.
There's something like 1600 calories in a box of spaghetti that costs ~$1-2.
You eat plain raw spaghetti with nothing on it? No, of course not. Bare minimum you spend energy to cook it and add tomato sauce when you eat it, the latter of which of course costs more than the spaghetti. Most people would add some sort of meat, some spices, maybe some cheeese, maybe have a drink with it, etc. But hey, let's pretend that you eat your plain raw spaghetti.
200 calories takes you 5km. A 2015 prius has city consumption of 0,185L per 5km. Gasoline in the US costs about $0.60/L today. Meaning the gasoline to drive that distance costs 11 cents.
Bike if you enjoy it. But stop trying to force everyone to engage in your stupid f'ing hobby.
I'll just go ahead and point out that I'll not be bothered to listen to this "no, exercise is free, there's no environmental impact to walking or biking" tripe. There's a reason that Tour de France competitors burn 7000 calories a day. Exercise burns calories - that's what powers your muscles. That's the reason you get hungry after exercising a lot. And even if you lose weight, it's almost impossible to lose enough that your baseline metabolism lowers more than the exercise you spent achieving that weight loss. Or anywhere close. Bikes take very little energy to be propelled forward, but they get that energy in a horribly inefficient manner using an energy source with massive environmental impacts.
If you're going to exercise, good for you if you put the energy expended toward a productive manner. But there's many, many productive ways to exercise. I, as mentioned, like to exercise on my land, doing projects like planting trees to help with reforestation and erosion control, among others. Some people exercise by playing with their kids, nurturing them and getting peace of mind. Some people exercise by building things. Some people exercise by gardening. And on and on. There's tons of ways to put exercise to productive uses. Not simply your preferred way, cyclists. And don't in any circumstance try to force others to exercise because "it's good for them". Should I get to dictate what's "good for you" to you, what you may and may not do in your life?
I don't want to take part in your damned hobby. Stop trying to force me to take part in your damned hobby. And everyone else like me who has no interest in your damned hobby. Which is why most people don't take part in your hobby as it is.
2) Installing deliberate "baffles" to slow down traffic flow. For example, here on Snorrabraut they have the center lane as an alternating turn lane into every little side street, and the outerlane in each direction also repeatedly turn into turn lanes, so that drivers have to keep alternating between the left and right lanes... with stoplights at each little intersection, of course.
3) "Increasing density" by ripping out all of the parking. This has the lovely side effect of, during busy times, cars that normally would have just parked instead have to circle around for long periods looking for spaces. Great for the environment, that! They usually rip out the parking first and then worry about whether they actually have anything to build there later.
4) "Increasing density" by ripping out public spaces. The hardest one to see go was Hjartatorg, as it had been basically built up and decorated by the city's teenagers, murals covering every square meter of the sides.
5) "Increasing density" by pushing out lower density businesses that people actually enjoy, like entertainment, for high density residential (these days, often hotels or apartments for tourists) and higher profit commercial.
6) "Increasing density" by building "up". The city is covered in tower cranes, each competing to build taller buildings than the last, and all doing their damnedest to block views of the ocean and famous city landmarks.
7) Going hyperaggressive on parking fines. There's even parking meters at the hospital parking lot, and meter readers go around ticketing patients' cars - even emergency room patients. On Menningarnótt they shut down car access to the entire city - which would be fine (it's a big festival), except that they don't provide nearly enough parking even for people at bus stops wanting to catch the buses into the city that they're supposed to take, and then go around ticketing all the cars on the outlots.
8) Building new buildings with insufficient parking, or - latest trend - no parking at all.
And on and on. It's so ridiculous in general, but even more ridiculous here on one of the windiest places on the planet, where winter lasts half a year, where there's almost no sun in the winter, etc.
And for what? So that we can't go places when we're sick or injured? So people can't commute? So that we have to exercise in their proscribed manner rather than our own? (my way to exercise is planting trees and improving my land... screw you, environment!) So that we have to live in little apartments in a city with ever-shrinking public spaces and ever-decreasing view? So that we can use a means of transportation that's 20+ times more likely to get you seriously injured per kilometer than driving, and almost as likely to seriously injure pedestrians? So that we can burn ~40 calories per kilometer biking (significantly more walking) which, at a local average embodied CO2 per food calorie of something of probably around 6g/kcal works out to 240g/km, three times worse than driving alone in a Prius** (even if you lower your baseline metabolism that only saves you about 14kcal/day/kg body mass reduction, far less than you burn to achieve that weight loss**)? Just ignoring the potentially even bigger issues from producing all of that extra food, such as methane emissions, destruction of habitat, algal blooms, pesticide pollution, damm
But of course these aren't like Earth "water drops", they're more like frozen dust grains.
Still, potentially destructive.
There's interesting potential for future missions (almost assuredly ion-powered) to do Enceladus sample return by doing flybys with a carbon collector (better than the silicon aerogel used by Stardust). But for that you have other options than just doing a straight flyby - you could enter a highly elliptical orbit around Enceladus with the apogee - or the ascent - positioned over the geysers. The latter may be better because even if you had no relative velocity, the ice grains still have significant speed of their own, even at Enceladus escape. - so by ascending relative to Enceladus, you're further reducing (to a limited degree) the relative velocity at impact (some grains move slower than others, of course, you'll likely have some collisions in any circumstance at almost zero relative velocity). The craft could sit in orbit for a very long period of time, even years, until its collector is basically saturated, before sealing it, breaking orbit (little energy required if you're already in a highly elongated orbit), thrust-and-gravity-boost your way out of Saturn via flybys of other moons (giving additional science in the process), and return to Earth.
Regardless of the form, an Enceladus sample-collection mission wouldn't have to be limited to Enceladus. Other Saturnian moons have at times presented evidence of lesser cryovolcanism, and Saturns' many different rings themselves could prove to be potential collection targets if mission planners felt confident enough about the safety of the trajectory.
Basically, it builds up manufacturing lines for sealed crafts, with same seats, suits, life support, etc
"Airtight craft" are FYI anything but new and anything but rare. And as covered extensively above, when you're given way, way more mass you can throw around, you're never going to choose the difficult solution that actually going to orbit requires, you're going to pick some cheap solution for your "sealed craft", your "seats", your "suits" (most plans either call for no suits or jet pilot suits), your life support (also made far, far easier because they're going up for such short periods of time - even a scuba diver's "life support system" is more complicated), etc.
They're not pushing new ground for rocketry any more than making bottle rockets is.
SpaceX is commercial spaceflight. OSC is commercial spaceflight. Cheapo rockets that pop nearly straight up to 100km then fall back down aren't anything like commercial spaceflight. They're built around a very different flight envelope, very different performance characteristics, and consequently don't share much more in common than needing a pressure vessel. These things are joy rides for the wealthy.
I care about companies working to bring down actual access to space - that is, reaching orbit. These toys are not steps in that direction.
To point out the difference: These things go to just over 100km, because that's defined as the boundary of space. Actual low-earth orbit is more like 300-400km. But getting up is the easy part. Getting to a velocity of 7800 m/s / 17500 mph / 28000 kph that's the hard part - it takes 10 times as much energy as the getting-up part in an ideal situation (7-8 times in practice due to aerodynamic and gravity losses). Basically, they're doing ~30% of the task that makes up 15% of the actual task of getting to orbit, which is pretty much the bare minimum that matters for anything but upper atmospheric research. Given that the demands on rockets scale exponentially with the required delta-V (both in terms of thrust as well as other factors such as surviving reentry when you've got such high potential energy to burn off), it quickly becomes obvious that something in the sort of flight envelope of these joyrides isn't even touching on the actual challenges of spaceflight. They get away with cheap, easy materials and cheap designs with low-ISP propellants and far less weight-optimized designs because, well, they can. And when you only play around with the "easy stuff", you're not pushing the state of the art on the "hard stuff" forward.
To put it another way: we shoot tons of bottle rockets off every year, but they don't do a darn thing to make launching spacecraft to Mars any cheaper.
Slashdot Mirror
Aka graphite oxide. It's made from graphite, and has been around for over a century. It's considered the most promising candidate for producing affordable graphene (most of the other techniques for making graphene do so in rather small volumes at rather high cost), but tends to produce the lowest quality graphene. So it's really promising to see that this is the raw material that the graphene electrode is sourced from.
What I find interesting is that the paper says that they used a "reduced graphene oxide electrode". Graphene oxide was first produced in 1859. It's a rather cheap, mass-produceable material, not at all exotic. However it was only first reduced to graphite in 2012 as it was difficult to find a pathway. It's seen as a promising route to cheap mass-produced graphene compared to other routes, with the downside that the resulting product is usually lower quality (although they've made lots of improvements in the past few years).
In case you didn't notice, batteries have dramatically increased in energy density over time. No, a cell phone is not entirely a battery, but battery sizes have shrunk in conjunction with phone sizes, even while their capacity (mAh) has been rising (significantly) over time.
People's inability to notice changing technology around them never ceases to amaze me. It's astounding how fast people get used to new technology and forget what old technology used to be like. It's like picking up an old video game that you played as a teenager and being shocked at how bad the graphics were.
Actually this is far better (from what I can see of it) than any of the previous work on li-air, which I've always taken a rather long view on. While it's really unfortunate I can't read the paper to see the exact details to get an idea of the manufacturing process and read more about the nature of the testing and the drawbacks mentioned, getting 93% efficiency and 2000 cycles on lithium-air are really staggering figures.
The only drawbacks the article mentions are "because the battery's ability to charge and discharge is too low." Soooooo... does that mean low power density? If so, to that I say so what? Today's li-ion cells have way more power density than is needed for propulsion, that's why you have things like Teslas beating supercars - their peak power is something like 20 times what they need to cruise at highway speeds. You could drop discharge power density by an order of magnitude and still have a fine car (optionally with a supercapacitor or small high power-density li-ion pack for bursts if desired) . And for recharge power density... when you have the absurd energy densities provided by li-air, it ceases to matter any more. Seriously, when you can drive all day on a single charge, who needs rapid chargers? You just plug in and charge while you sleep, so it makes no difference whether you can do it in 30 minutes or 8 hours. The top end of Level 2 charging should be enough to give a reasonably efficient vehicle a whole day's drive, no need for Level 3+.
I'd gladly take way lower power density in exchange for way higher energy density.
From the paper's abstract, I see that the chemicals involved in the battery are LiO2, graphene oxide, LiI and dimethoxyethane. LiO2 is cheap. Graphene oxides vary quite a bit depending on the preparation method, so it depends on what varient she's using, but most are cheap. Lithium iodide is cheap. Dimethoxyethane is cheap. Seriously, unless she's using an unusual rare/expensive form of graphene oxide, or is doing something weird and potentially costly in the manufacturing process, these should be affordable.
I really wish I could read more about the details, as that's where the devil lives, but... damned restricted access, yadda yadda yadda. :P
A drone might be harder to target than a medevac helicopter. It has no crew, only needing to carry the one patient, so it can automatically be much smaller and lighter, which means a smaller target and lower heat signature. And that's assuming it's still combustion-powered. An electric medevac drone would obviously have a much shorter range, but could still be useful to get people from a raid back to a FOB. Switching from ICE to electric would further reduce your heat signature 3-4 fold. It could (potentially) also be quieter.
Smaller could also potentially mean "portable". A team raiding a village could potentially bring one with them, leaving it ready to go on the outskirts. Which raises other possibilities: transporting people into raid areas (although you'd have little to no armour) or even transporting secured prisoners out.
While electric sucks in terms of range per kg, it excels in terms of power per kg. So if you're not trying to move people far...
Yeah - I think the concept of "dropping" munitions is thinking about it wrong. If you're dropping it, then it has to be a "smart munition" (wherein what's the point of a smart carrier?"), and if it's dumb, you're never going to hit by just dropping. And if you're not considering your craft expendible than you have to try to protect it, and you have to have the range to get back. Which rules out deploying your drones as effective "submunitions" of another delivery vehicle (drones dropped by plane, balloon or rocket technically don't even need motors, just control surfaces to control their glide to their targets)
"modified consumer drones" = cheap, but with camera and a degree of processing power = suicide seeker craft. Give it enough power to do basic image recognition, run it remotely until it gets (inevitably) jammed wherein it switches over to automated tracking and does its best to hit its target, in as rapid of a dive as it can manage. Plastic/composite = low radar cross signature. Small visibility cross section, and could be made out of clear plastic if desired. Low heat signature - on a glider, nearly none. You're talking something very hard to detect, and very hard to hit even if you detected it. And probably a lot cheaper than any countermeasure rocket you might try to launch at it. It doesn't take some massive weapon to take out an armoured vehicle - usually 1-4kg, depending on the warhead. So while we're not talking microdrones here, we're not talking about something huge either.
In a way, weapons are already moving in this direction. Look at the Javelin, for example. It doesn't just home in on a the center of some heat source - it uses multiple spectral frequencies and a 64x64 pixel sensor and processes the images with pattern-matching algorithms to aim for the place where the target will be located (not where it is), to avoid being tricked by decoys, and to pick the "sweet spot" on its target. It goes up - by rocket power, not prop power, but nonetheless - cruises laterally, then rapidly descends on its target. The operator doesn't need to be at the location of firing or continuously paint the target. Etc. It's a rocket, not a drone, but one can see the same strategy applied to drones. The main difference is that a rocket uses a big heavy, obvious thrust system to try to get to a target before it can get out of the way or hide, while a drone does its best to not be seen, taking its time until it finds a good opportunity and then striking.
They say that P-P-P-PowerOS is rather nice, but it only runs on specific laptops.
Every piece of software contains at least one bug.
Also, every piece of software code can be shortened.
Therefore, every program can be shortened down to an empty source file which doesn't work.
Oh god, don't get me started on SLS. Have you seen the launch cost estimates? They're currently looking at $14k/kg to LEO not counting development costs, and assuming that you can manage to load the thing fully. Counting development, that depends on how many launches they make before they inevitably decide to cancel the way-too-expensive rocket. Most estimates I've seen so far put the development-included per-launch figure in the very rough ballpark of $40k/kg.
For people who know space, you already know that an "average" launch cost is $10k/kg to LEO. Russian and Chinese costs are usually around $7k/kg, sometimes cheaper. Falcon 9 is... if I recall correctly, about $5k/kg right now, maybe less. A rocket that costs $14k/kg, and that you have to lift something very heavy with every time, a billion dollars every time you fire the thing off... they might as well just paint the words "CANCEL ME" on the side.
Mars is far better mapped than the bottom of the oceans. Far, far better.
Lookup HiRISE for an example. It's on MRO which is in a low orbit around Mars, yet from Mars it was able to image Earth and the moon at 90 and 24 pixels across, respectively. It's taken pictures of 1% of Mars's surface at a resolution of *0,3 meters per pixel*. The highest resolution on Google Maps of Earth is 0,5 meters per pixel. I think the last full-planet coverage of Mars I saw was 3m/pixel, but it could be higher by now. Do you think we know the bottom of the oceans anywhere near that well?
"Trillion" is certainly a sizeable overestimate. But the Zubrinians (let alone the Mars One Nuts) are just in the opposite, far too optimistic in the other direction.
Everything else you wrote I entirely agree. I'd add that it's especially true when people try to push humans by arguing that "It's for Teh Science!" Because humans can do so much more, you see? Because they apparently have HiRISE imaging systems in their retinas and mass spectrometers in their palms and maybe a setup for X-ray fluorescence under their ears or something.
The reality is, science is done by... gasp...wait for it... scientific equipment. So of course you can send a human and have the human operate the scientific equipment, no question there. You could have a human orbiting Mars running HiRISE for example. But of the two things - the person and the telescope - which component is the one that's actually needed and which one is the remora hanging onto the side?
On the surface, yes, humans can reduce latency. To that I have to say: .............. and? .............. so?
What the heck does latency matter? We can only afford to launch a mission every few years. What does it matter if it takes the mission three days or three years to get its results? And no, humans aren't just going to "spot" neat things that a rover wouldn't - the rover's "eyes" are far better than the human's. And the rover operators control the rover to be just as "curious" as a human would be - moreso, really, because they have to long to plan every little tiny step. They launch whole investigations on what the ground looks like after the wheels kick it up or why the sand in one place slips a little bit more than in a place a couple dozen meters up the path.
The other one human spaceflight fans add is "repairing". Because, you see, failed Mars missions could have been saved by humans. SAVED! Except for, of course, manned spaceflight adds an order of magnitude more ways for the vehicle to fail. And most failures cannot be saved from. Seriously, check a list of how spacecraft en route to Mars have been lost. CATO launch failures. Failure to reach orbit. Failure to leave Earth orbit. Incorrect insertion trajectory calculations. Instability during reentry. Landing system hardware failures. And on and on. How is a human supposed to save these things? There's a few humans could have saved, but the large majority, no.
Humans eat up the vast majority of your payload. Without the remoras onboard and all of the associated systems for giving them a roomy, pressurized environment and keeping the chemical ratios therein balanced and shielding them from radiation and giving them water (heavy) and having water recycling systems and toilets and food stocks and carbon dioxide scrubbers and beds and exercise equipment and medical systems and let's not forget a whole habitat to live in when they get there, you'd have 1-2 orders of magnitude more payload return capability.
For all of the "benefits" of sending humans they want to raise the cost of a Mars mission by 1-2 orders of magnitude. For the same amount of money e could send dozens of diverse science missions to every corner of the planet containing every conceivable scientific payload and returning samples from bloody everywhere. Or we can send people to one place with a far smaller set of scientific equipment, because all of their budget was eaten up on the whole "keeping humans alive" thing.
But hey, we'd reduce the latency...
Or was there some sort of relevant / interesting information in the article somewhere that I somehow didn't see?
And really, we're linking peoples' linkedin profiles in article summaries now?
It's really hard to extradite from the EU anyway even for non-politically-connected crimes. It took 8 years even to get Abu Hamza, which was about as open and shut as possible (including convictions in the UK) for about as hateable of a figure as possible for serious of crimes during a period where there was a major push to prosecute said crimes. The ECHR in particular is a major refuge for people arguing political prosecution. The right in many countries like the UK hates them, as they make it hard to prosecute many types of crime and force them to guarantee all sorts of rights for prisoners (like assisted reproductive services for sex offenders and such). In the case of Abu Hamza, they ruled that a variety of conditions in US prisons are "torture" and he couldn't be extradited until the US promised to make all sorts of restrictions on how he would be housed. They also had to agree to not seek the death penalty, and nearly required the US to not seek life in prison either. And if the US would ever break any of their promises, the ECHR would impose a general ban on extradition to the US (as they've done with many other countries), as it's against EU law to extradite to countries who do not have a track record of upholding their pledges concerning prisoners (it was imposed in the aftermath of the Agiza/Alzery case)
Now, this shouldn't be confused with moving people between EU states under the EAW process (surrender, not extradition), which is generally rather easy. EAWs bypass the executive branch entirely, and the automatic presumption is that the warrant is valid and should be enforced rather than the other way around.
Honestly, what would work out best for everyone would be if the US agreed to plea bargain with Snowden. He seems interested in it, the US would still send their message that "you can't run from the law forever", etc.
It's very common to own "summer homes" rather than land, although sometimes the summer homes come with land. My plan is actually to build a full-time single family house there (being a nerd, it'll be an underground steampunk cave house built supervillain-style into the side of my canyon ;) And no, that's not common here ;) ). Most people don't build full-time houses that far out unless they're farmers because they can't be bothered to have to drive half an hour to work. But lots of people drive 15-20 minutes to work, from Mosfellsbær or Hafnarfjörður to Reykjavík.
According to something I read on Slashdot, since then we've all become cows. Which would now that I think about it be pretty compelling evidence of rapid evolution.
Also, moo.
Yes it is. It's data about where there is no data. Example:
Bob: I firmly believe there is rabid gorilla loose somewhere in this city..
Jane: I just searched my home. There's no evidence of a gorilla.
Bob: The absence of evidence is not evidence of absence!
Jane: I just searched 100 homes. Still no evidence of a gorilla.
Bob: The absence of evidence is not evidence of absence!
Jane: I just searched 10% of the town. Still no evidence of a gorilla.
Bob: The absence of evidence is not evidence of absence!
Jane: I just searched 95% of the town. Still no evidence of a gorilla.
Bob: The absence of evidence is not evidence of absence!
Jane has a shortage of data about the presence of a gorilla. But the lack of finding data despite active search is itself very valuable data.
You're way south of us. That means far more light. In December/January, most days get no direct light at all, because while there's technically daylight, the sun is so low that almost anything can block it.
We're one of the windiest places on Earth. In the continental US, windspeeds like those found in Reykjavík (which peak BTW in late winter / early spring) are only found in the windiest parts of the Rockies and a couple other small isolated locales. Last winter there wasn't a single period that went more than three days without a windstorm, most very strong. One windstorm had 60m/s (130mph) winds at my land. Want to bike in that?
Our "winter", if you want to define it as the period in which you're likely to freeze your butt off , risk getting caught in a snowstorm, bike across ice, things of that nature, lasts for nearly half the year.
Really? So what clothes suit 60 m/s winds while biking on a smooth sheet of ice?
I live in town but own land in the countryside (Hvalfjörður), about half an hour from downtown / 15 minutes from the outskirts (Mosó). Eventually I'll be moving out to my land, but not yet.
Which is why daily commuters don't eat a whole pig for dinner every night. But it's not as if you either need to eat an additional 5000 calories or there's no change whatsoever to your daily diet. Riding a bike at moderate speed burns about 40 calories per kilometer over one's baseline.
Morbo Voice: "CALORIES DO NOT WORK THAT WAY!"
It's a very simple equation: calories in vs. calories out. Your body doesn't just toss away excess calories. Your body never excretes anything that it can just digest. The way your body changes the in/out balance is by varying your hunger level, which highly correlates with how much you eat. The only way to throw off the equation is by gaining or losing enough weight to have a practical effect on the baseline. But the baseline change with increasing or decreasing weight really isn't that significant. Your average person would have to lose 30-40 kilograms to make up for a short 7km-each-way bike commute. Do you really think commuting 7km to work on a bike is going to make your average person to lose 30-40 kilograms? Of course not. They might, might lose 5kg in an average case, 10 in a good case, maybe 15 in a really good case... and that only if you're not forcing them away from other exercise in order to do so.
The energy simply does NOT come from nothing. It comes from making you hungry and thus causing you to eat more to replace what you burned. If you disagree, you're in disagreement with medical science, and I don't suffer kooks.
1) The efficiency of food distribution is pathetic compared to the efficiency of oil distribution. When was the last time you saw a supertanker full of chicken wings unloading into a pipeline?
2) The energy required for distribution is built into the (very high) CO2 cost for producing food. Which is only one of food's numerous environmental problems.
You eat plain raw spaghetti with nothing on it? No, of course not. Bare minimum you spend energy to cook it and add tomato sauce when you eat it, the latter of which of course costs more than the spaghetti. Most people would add some sort of meat, some spices, maybe some cheeese, maybe have a drink with it, etc. But hey, let's pretend that you eat your plain raw spaghetti.
200 calories takes you 5km. A 2015 prius has city consumption of 0,185L per 5km. Gasoline in the US costs about $0.60/L today. Meaning the gasoline to drive that distance costs 11 cents.
Bike if you enjoy it. But stop trying to force everyone to engage in your stupid f'ing hobby.
I'll just go ahead and point out that I'll not be bothered to listen to this "no, exercise is free, there's no environmental impact to walking or biking" tripe. There's a reason that Tour de France competitors burn 7000 calories a day. Exercise burns calories - that's what powers your muscles. That's the reason you get hungry after exercising a lot. And even if you lose weight, it's almost impossible to lose enough that your baseline metabolism lowers more than the exercise you spent achieving that weight loss. Or anywhere close. Bikes take very little energy to be propelled forward, but they get that energy in a horribly inefficient manner using an energy source with massive environmental impacts.
If you're going to exercise, good for you if you put the energy expended toward a productive manner. But there's many, many productive ways to exercise. I, as mentioned, like to exercise on my land, doing projects like planting trees to help with reforestation and erosion control, among others. Some people exercise by playing with their kids, nurturing them and getting peace of mind. Some people exercise by building things. Some people exercise by gardening. And on and on. There's tons of ways to put exercise to productive uses. Not simply your preferred way, cyclists. And don't in any circumstance try to force others to exercise because "it's good for them". Should I get to dictate what's "good for you" to you, what you may and may not do in your life?
I don't want to take part in your damned hobby. Stop trying to force me to take part in your damned hobby. And everyone else like me who has no interest in your damned hobby. Which is why most people don't take part in your hobby as it is.
And I utterly despise it. Here's how it works out.
1) They tear down lanes, increasing traffic, and turn them into ugly, overly broad sidewalks and bike lanes that nobody uses,
2) Installing deliberate "baffles" to slow down traffic flow. For example, here on Snorrabraut they have the center lane as an alternating turn lane into every little side street, and the outerlane in each direction also repeatedly turn into turn lanes, so that drivers have to keep alternating between the left and right lanes... with stoplights at each little intersection, of course.
3) "Increasing density" by ripping out all of the parking. This has the lovely side effect of, during busy times, cars that normally would have just parked instead have to circle around for long periods looking for spaces. Great for the environment, that! They usually rip out the parking first and then worry about whether they actually have anything to build there later.
4) "Increasing density" by ripping out public spaces. The hardest one to see go was Hjartatorg, as it had been basically built up and decorated by the city's teenagers, murals covering every square meter of the sides.
5) "Increasing density" by pushing out lower density businesses that people actually enjoy, like entertainment, for high density residential (these days, often hotels or apartments for tourists) and higher profit commercial.
6) "Increasing density" by building "up". The city is covered in tower cranes, each competing to build taller buildings than the last, and all doing their damnedest to block views of the ocean and famous city landmarks.
7) Going hyperaggressive on parking fines. There's even parking meters at the hospital parking lot, and meter readers go around ticketing patients' cars - even emergency room patients. On Menningarnótt they shut down car access to the entire city - which would be fine (it's a big festival), except that they don't provide nearly enough parking even for people at bus stops wanting to catch the buses into the city that they're supposed to take, and then go around ticketing all the cars on the outlots.
8) Building new buildings with insufficient parking, or - latest trend - no parking at all.
And on and on. It's so ridiculous in general, but even more ridiculous here on one of the windiest places on the planet, where winter lasts half a year, where there's almost no sun in the winter, etc.
And for what? So that we can't go places when we're sick or injured? So people can't commute? So that we have to exercise in their proscribed manner rather than our own? (my way to exercise is planting trees and improving my land... screw you, environment!) So that we have to live in little apartments in a city with ever-shrinking public spaces and ever-decreasing view? So that we can use a means of transportation that's 20+ times more likely to get you seriously injured per kilometer than driving, and almost as likely to seriously injure pedestrians? So that we can burn ~40 calories per kilometer biking (significantly more walking) which, at a local average embodied CO2 per food calorie of something of probably around 6g/kcal works out to 240g/km, three times worse than driving alone in a Prius** (even if you lower your baseline metabolism that only saves you about 14kcal/day/kg body mass reduction, far less than you burn to achieve that weight loss**)? Just ignoring the potentially even bigger issues from producing all of that extra food, such as methane emissions, destruction of habitat, algal blooms, pesticide pollution, damm
But of course these aren't like Earth "water drops", they're more like frozen dust grains.
Still, potentially destructive.
There's interesting potential for future missions (almost assuredly ion-powered) to do Enceladus sample return by doing flybys with a carbon collector (better than the silicon aerogel used by Stardust). But for that you have other options than just doing a straight flyby - you could enter a highly elliptical orbit around Enceladus with the apogee - or the ascent - positioned over the geysers. The latter may be better because even if you had no relative velocity, the ice grains still have significant speed of their own, even at Enceladus escape. - so by ascending relative to Enceladus, you're further reducing (to a limited degree) the relative velocity at impact (some grains move slower than others, of course, you'll likely have some collisions in any circumstance at almost zero relative velocity). The craft could sit in orbit for a very long period of time, even years, until its collector is basically saturated, before sealing it, breaking orbit (little energy required if you're already in a highly elongated orbit), thrust-and-gravity-boost your way out of Saturn via flybys of other moons (giving additional science in the process), and return to Earth.
Regardless of the form, an Enceladus sample-collection mission wouldn't have to be limited to Enceladus. Other Saturnian moons have at times presented evidence of lesser cryovolcanism, and Saturns' many different rings themselves could prove to be potential collection targets if mission planners felt confident enough about the safety of the trajectory.
"Airtight craft" are FYI anything but new and anything but rare. And as covered extensively above, when you're given way, way more mass you can throw around, you're never going to choose the difficult solution that actually going to orbit requires, you're going to pick some cheap solution for your "sealed craft", your "seats", your "suits" (most plans either call for no suits or jet pilot suits), your life support (also made far, far easier because they're going up for such short periods of time - even a scuba diver's "life support system" is more complicated), etc.
They're not pushing new ground for rocketry any more than making bottle rockets is.
SpaceX is commercial spaceflight. OSC is commercial spaceflight. Cheapo rockets that pop nearly straight up to 100km then fall back down aren't anything like commercial spaceflight. They're built around a very different flight envelope, very different performance characteristics, and consequently don't share much more in common than needing a pressure vessel. These things are joy rides for the wealthy.
I care about companies working to bring down actual access to space - that is, reaching orbit. These toys are not steps in that direction.
To point out the difference: These things go to just over 100km, because that's defined as the boundary of space. Actual low-earth orbit is more like 300-400km. But getting up is the easy part. Getting to a velocity of 7800 m/s / 17500 mph / 28000 kph that's the hard part - it takes 10 times as much energy as the getting-up part in an ideal situation (7-8 times in practice due to aerodynamic and gravity losses). Basically, they're doing ~30% of the task that makes up 15% of the actual task of getting to orbit, which is pretty much the bare minimum that matters for anything but upper atmospheric research. Given that the demands on rockets scale exponentially with the required delta-V (both in terms of thrust as well as other factors such as surviving reentry when you've got such high potential energy to burn off), it quickly becomes obvious that something in the sort of flight envelope of these joyrides isn't even touching on the actual challenges of spaceflight. They get away with cheap, easy materials and cheap designs with low-ISP propellants and far less weight-optimized designs because, well, they can. And when you only play around with the "easy stuff", you're not pushing the state of the art on the "hard stuff" forward.
To put it another way: we shoot tons of bottle rockets off every year, but they don't do a darn thing to make launching spacecraft to Mars any cheaper.
** of understanding
Shuold porff raed betre.