From what I can tell in a brief skim, it really does pose a fundamental limit given current technology. The problem is that with the largest mirror we can imagine getting up into space, and with the highest sensitivity sensors, the signal-to-noise ratio is still too low to get a usable measurement without taking hundreds of measurements.
They plan to detect the chemicals in the atmosphere by measuring the absorption bands in the starlight as some of it passes through the atmosphere. This is presumably going to be a lot more sensitive than trying to detect the light from the planet directly, since you have a lot more photons to carry the information. The signal to noise ratio in this case is really limited by the unfortunate fact that light energy is discretized and you can't make finer measurements than a single photon. Thus a large mirror with a high-quantum efficiency (95%) sensor, is really the best you can do.
The only hope to improve this is to either get bigger mirrors, which really depends on improving space access and is unlikely to give order of magnitude improvements, or to implement an as yet unrealized method that is able to get more information. If it were a problem of angular resolution there are plenty of interesting tricks you could use to improve it. Unfortunately I can't think of anything better, and it doesn't seem anyone else has yet either. Of course, that doesn't mean no one will... but its not as simple as just designing the next mission.
Actually... random 3:30 am idea... if you did something in thermal-IR, and measured the absorption of the blackbody emissions of the planet by the atmosphere you might be able to get something working. The intensity would be a lot lower than looking at the stars light, but the dimming due to absorption would be much larger percentage-wise... although it would take some heavy math to show if it would actually give you a better SNR. Of course, there are plenty of holes here: among other things, my knowledge of atmospheric chemistry and absorption is very limited, and this would all depend on being able to resolve the star separate from the planet, and would thus rely on some complicated interferometric methods....... and you'd have to block out the star light to be able to get the planet light as anything more than noise... and probably the number of photons in thermal IR from a planet are too low to be able to even see it on its own... but maybe I'm wrong and it could work, or something else can.
I think if someone had a solid path to go down for developing FTL travel they would have no trouble finding funding. In fact I think that would have the effect of encouraging more missions like Kepler, so we would have good places to go once we got it working.
I'd venture a guess (I'm not involved in anything similar to that kind of physics) that the kind of results that would lead to a radical new form of propulsion wouldn't come from a heavy focus of funding, but rather continued support of seemingly impractical physics research in many or all directions.
Heavily directed funding is great for improving the efficiency, reliability and capabilities of current ideas, but can't really lead to the kind of radical breakthroughs FTL would require. A nice succinct quote from the West Wing TV show: "If it was up to the NIH to cure polio through a centrally directed program, you'd have the best iron lung in the world but not a polio vaccine."
I don't think the idea is to find a new place for us to live. Obviously, our ability to take advantage of such a planet is incredibly limited.
Rather, its to understand what the possibilities for life outside our planet are. Putting it in simplest terms, its working to get experimental data for some of the coefficients in the Drake equation.
Unfortunately I think coming up with something truly new to do with high-school level equipment and a teacher's who doesn't spend a lot of their time doing research might be difficult.
That said, rather than trying to do new science, contributing to experiments and observations in a way thats more involved than Folding@Home would be easier. My recommendation, because it's something I'm working on right now, is asteroid hunting. A decent robotic observatory with a ~3-4" scope can do it quite well. If you could find a local person who has a respectable setup and would be willing to donate a few nights on their equipment, it would be pretty straightforward.
During the day you'd have the students pick out a dozen or two dozen sky segments, submit plans to the robotic site to image each section a couple of times, an hour apart. You get the pictures back the next day in class, compare the results and see if there are any moving objects in the field of view. If so, you've found yourself an asteroid. After this you can pick out its angular location from the known picture location, and with the time you can pick out its trajectory and compare it to databases that are out there, chances are good you'll have found something new. I know there are some articles on the internet that give better information, I'm still looking to set it up for a scope I'm working with. Also the chance of finding an asteroid is supposedly about 1 in 6 from any particular sky region.
Fair enough, although someone is telling us we can't. Maybe an overambitious local FAA office, maybe DHS, maybe the school administration. I'm guessing its similar regulations that we have to deal with for UAV's. Also, we're based out of College Station, TX and have a limited budget, so we can't go all the way out to White Sands or somewhere similar. We're right between Houston, Austin, and Dallas, and the area around Waco hasn't been usable for the past 8 years because of Bush's ranch. It's really an annoying area to deal with. We also do spend quite a bit of time getting the permits to fly, still limited to a mile altitude.
So while I'm not sure on where all the restrictions are coming from, we keep getting more and more restricted in what we can do, and although there are ways to get around many of the issues, our budget isn't big enough to allow us to do those things. I think Armadillo does most of their higher altitude testing out in Oklahoma, which is really outside of our practical range, although that is a good suggestion. I actually know people there, but haven't talked to them about these particular problems, I finished being directly involved a while ago.
While some simple licensing might be in order, in my experience the government is severely, ridiculously restricting model rocketry right now. For our senior design class we build ~150-lbf hybrid rockets that reach a mile in altitude (reasonably limited by the FAA in moderately dense airspace).
We've always had some restrictions, mostly from the school and the FAA. The school doesn't let us build our own solid motors because of safety, and we have to go through a lot of paperwork with the FAA to schedule launches. We had to move from our old launch site because it was pretty close to Crawford, TX. Lately (as I commented before) they've cracked down on guidance systems, which I think is crossing a line, but is at least within the realm of being reasonable.
Just this year, though, Homeland Security has gone to a new level of ridiculous, informing the advisor that the project now fell under International Trade in Arms Restrictions (ITAR). WHat this implies is that we can't tell any foreign nationals what we do... if there's a foreign student on the team they're not allowed to see any of the old classes materials. I was working to post a lot of information on the wiki for a student organization with a lot of chapters that do similar scale rocketry, showing our designs, the design equations, what equipment we've used, testing equipment, etc. Only now, I can't do that because if I did I'm afraid I'd bring legal trouble onto the organization which really doesn't have the resources to deal with it. So instead of being able to work collaboratively we're stuck recreating the wheel most of the time.
Bypassing the fact that ITAR is a noose thats going to tighten on the US space industry eventually, I find it amusing that a project developed by a bunch of undergrads could possibly pose a threat to proliferating missile technology. The rockets that fly out of Gaza on a regular basis seem to able to fly much further than ours, and are probably much more robust, practical designs, since ours tend to go in a 'I wonder if we can do this?' kind of direction. I'm also pretty sure they'd be happy to share their knowledge with plenty of the people we're worried about spreading the technology too.
In addition to not being a trivial exercise, the Feds tend to view building a guidance system as going beyond model rocketry to building a guided a missile, which they frown on. You might be able to get away with very small ones, but I don't really have a good feel for what the minimum weight you could get for servos, control computer and sensors would be, and what size rocket that would indicate.
We build ~150-lbf thrust hybrid rockets for our senior design projects, and in the past few years its become more and more difficult to do anything interesting because of increased restrictions, from the school administration, the FAA, and Department of Homeland Security. Having a launch site that was pretty near Crawford, TX also made things difficult, had to find a new launch site.
One of my friends, who works at a satellite design company, was debating another employee on some aspect of the thermal design for a top-level systems design, using some data from a book called "Space Mission Analysis and Design" (SMAD). At this point the other guy corrects him pointing out the limitations of the table he was using, then tells him to look at the beginning of the chapter. Turns out the guy he was arguing with had written the thermal control chapter.
Although he does seem to be a bit of an ass about it, there is a distinct non-linearity between GPA and ability. While I would never claim grades don't matter, I wouldn't trust the design work from anyone in my department who's doing better than about a 3.8 in undergrad. (I'm about to graduate with a masters in Aerospace Engineering.) Not to generalize too much, but the ridiculously high GPA students tend to be completely incompetent at any practical applications, and also are fairly obnoxious because they don't recognize their limits and tend to assume they're better than everyone else. Of the few I've known in our department there's only one that I have much respect for.
Beyond that, (again generalizing, I apologize), people who are in the 3.4-3.8 range (where I am) are going to be much better at theoretical analysis and systems level work, while when you're designing a part to be sent to the machine shop I'll take the guy with a 2.8-3.4 who worked in a machine shop through high school any day.
Really, what I think, and what I've heard from some interviewers I've worked with on internships is that what projects you've done, and what roles you played is the most valuable indicator of how you'll do. Of course, anything below around a 3.0 does rightly raise questions about commitment (but shouldn't be a deal-breaker).
Actually, I agree with you, even if Dr. Gates doesn't. The real problem with the F-22 right now is that for whatever reason (it could be a good one or not, I don't know), its being cast as either we make them all now, or just let the whole program go. Really what would be the best way to go in my mind is to simply spread out the production, defraying the costs and allowing us to pay for and prosecute the current conflicts while not completely halting development on future systems.
I think in addition to your reasoning, it simply comes down to the fact that the past 15 years have been a very unipolar world, where all conflict is by necessity asymmetric. However, with the tides swinging away to a highly multi-polar world, more conventional conflict and peace-keeping/counter-insurgency will both have to be accounted for, and as such research needs to be directed in both directions.
That said, I have a lot of respect for Dr. Gates (I attend Texas A&M where he was president until he took SecDef), and I think a lot of his position here is simply a counterbalance to the pie-in-the-sky overreaching of Rumsfield. I'm certain he's not so shortsighted as to completely ignore the future for the sake of the present.
Also today, a judge struck down the gay marriage ban in California in 2005, Karl Marx died in 1883, Albert Einstein was born in 1879, and the first town hall meeting in America was held in Faneuil Hall in Boston in 1743. So maybe we should all mourn Marx and the way his theories were manipulated/failed in the Soviet Union. Or maybe we should all celebrate Einstein by riding on very fast trains and shining lasers at each other. Or celebrate New England-style democracy. Celebrate a victory for gay rights or mourn your family values as the case may be.
There are a lot more important events in history than there are days in the year. And to be honest, most of history is pretty depressing, with plenty of horrible things happening... if we insisted every day on remembering all the terrible things that have happened, it would get very old very fast, and I imagine you'd see an upswing in suicide statistics. Learning from the past is important, but insisting on dragging down every day by revisiting it is absolutely ridiculous.
You're right, it wouldn't be useful for a full, conventional conflict with a country like China or Russia, or even pre-invasion Iraq. However, since the fall of the Soviet Union we've been much more involved in police action (the Balkans, Somalia) and insurgency fighting (Iraq and Afghanistan). When they say safe from missiles, they mean safe from shoulder mounted rockets that can devastate helicopters, low-flying aircraft, and any aircraft on take-off or landing. Having something that high with 10 years aloft means that its safe in this style of modern warfare.
Also, while minute-by-minute persistence, what you get from this, is much more important in this kind of asymmetric warfare. Fighting a conventional battle with a large army involves tracking troop movements and other large-scale things that are hard to hide from a satellite. However, for finding insurgents in Baghdad or tracking fighters crossing the border between Afghanistan and Pakistan, persistent observation where you can follow an individual's or small group's movements is much more valuable.
The current Secretary of Defense is very big on fighting the current wars instead of developing more cold-war relics like the F-22, so this seems right in line with his priorities, and it makes sense. If it were intended for spying on US cities, they would be trying to keep it much quieter and, as others have pointed out, it wouldn't really be impossible to see the airships. Given the (correct) uproar over the NSA wiretapping, which only focused on phone-calls going out of the country, I can only imagine how quickly such a program would be brought down, especially given how much harder it would be to hide.
As someone who's grown up in Oklahoma and Texas (kind of southern, kind of midwest), sir and ma'am do indicate respect, but not solely subordinate-to-superior. As often as not, it can also be used as a sign of mutual respect between equals, which does, I feel, go along with the American egalitarian ideal.
As far as our tendency to elevate public servants to positions of authority over us, I can understand the confusion. I think it's a general extension of republicanism (small-r), where we elect people to rule us, placing them in authority even though we know in the end, they're subservient to the people.
Beyond that, while we do value our freedom, we also tend to take comfort in order and the rule of law. I think that also helps explain our near-religious adherence to our Constitution: by holding to it like we do we're able to sustain an effective government and a strong sense of law and order while maintaining our freedom and growing more equal over time (yes I'm aware we do screw it up sometimes). I read somewhere that in France they say that in America, the people are afraid of the government, while in France, the government is afraid of the people. I think these odd habits of ours are related. If I remember correctly France has had 7 or 8 revolutions and changes in government systems since we instituted our system... in their minds, if the government gets too powerful and oppressive its high-time for a revolution. Here in America though, we've stuck with our system for quite a while and see it as something more than mere laws, its part of who we are as a people, and gives an overriding sense of stability and the rule of law. We're scared of giving the government more power than what it has because the idea of replacing the system is almost unimaginable.
I hope my ramblings make some sense of our point of view... obviously its not perfect, but it works pretty well for us.
Different kind of privacy. Some things, like health conditions, SSNs and credit card numbers, you don't want the government, corporations, insurance companies or identity thieves to be able to mine out of large databases or find in a deep background check. Other things, like your affinity for bodice-ripping novels or the fact that you secretly love the latest Britney Spears or Backstreet Boys (are they still around?) CD are things you just don't want to advertise as you're sitting on the bus or waiting in line.
Personally, I just prefer the convenience of e-books. While I do like that you can read one-handed, its because the single thing I hate most about real books is trying to hold them open while you're eating and reading at the same time.
My apologies. I'm not an expert on e-ink technology, my personal field of study of dynamics and control of space systems.
All I was doing was letting others know of my first-hand experience, and the biggest issue that I've had. While I may have been imprecise in my language, since I have no reason to state that you are incorrect, and wikipedia seems to corroborate you, I do know that the screen in the Kindle (which is also the same screen as the Sony PRS-505), is manufactured on glass backing. This was probably selected for structural and weight issues, but I wasn't involved in that so I can't say for sure. At any rate there are many examples of the screen backing shattering under direct pressure.
There are a number of issues where I can be accused of being in a bit of a fantasy world: I believe in God, I have hope there's life on Mars, I still believe in a small government after 12 years of so-called republican rule, and hell, I still secretly believe that a space elevator can work. However, in this case, I was just relating my own experience, and I have trouble seeing how I displayed any predilections towards unicorns, or really anything but a lack of knowledge of display technology.
So... my recommendation, quit the trolling. You could have just posted a correction, pointing out where I was wrong. I would have looked into it more, and learned something for the day, as might other people reading the thread. Instead, the biggest thing I got is a reminder that the world is full of assholes, and that they're not scared to come out on the internet.
Then don't buy it. If its usage doesn't appeal to you, then don't buy it. It doesn't change the fact that its expensive because of eInk, and it doesn't change the fact that some people decided it was a major selling point. I for one find it incredibly pleasant to read of off, and I like to read long-form novels, so it works wonderfully for me.
That's the great thing about having an open market, you can use what appeals to you. I personally like to tinker, so I have linux on my desktop and server, but want a laptop that works all the time, so I use a Mac there; if someone else uses Windows it doesn't bother me at all, as long as they don't expect me to as well. I also really like Dr. Pepper, that doesn't mean everyone has to agree with me. Some prefer coke, or diet coke, or even just drink water, since it is quite a bit healthier... as long as theres enough of a market the DP keeps selling it, it just doesn't bother me much. No need to belittle a product just because its something you wouldn't use.
From experience with the Kindle 1, which I've had for ~ 6 months, its a very durable device with the exception of direct pressure on the screen. I've accidentally spritzed it with water and soap, so as long as you're not giving it a bath it does fine. I stick it in my backpack on the way to school and takes a fair amount of abuse that way.
However, the one sticky point is that the screen is very susceptible to direct pressure on the screen. Because the e-ink relies on a glass backing for its operation, if you lean too heavily on it, it will shatter and the screen will be non-functional. This happened to mine when I had it on my bed and it disappeared under some blankets and I put my palm down on it crawling back into bed. Fortunately, I had a very good experience with Amazon customer service and received a new one within a few days. Keeping it in its leather carrying case and being aware of it eliminates those problems for the most part, and it can take quite a bit of abuse with just minimal precautions.
With how thin the new version is, and the fact that the case doesn't come standard, I wonder if the screen isn't more durable on Kindle 2. Can't say I'd want to test it myself though...
Without any actual analysis, I'll go out on a limb and estimate it would cause as much havoc as any large man-made piece of junk out there, like say a dead Soviet satellite. A much larger asteroid would be a different story, since not only would it have a larger footprint, but would also have hard-to-predict gravitational effects on all the satellites that got too near it. Of course, we're doing a pretty good job of detecting larger NEOs now... Apophis is the most problematic, mostly because we simply don't have high enough precision knowledge of its position to know where it will be in 2029 and 2036.
While you're absolutely correct, there is a program known as Operationally Responsive Space (ORS) thats being headed up by DoD rather than NASA that is headed in that direction. I think the time-frame they're considering is closer to 2 weeks, but the general idea is to be able to recognize a need, and design, construct and launch a mission in that period of time. That includes getting adjustable plug-and-play parts (GNC, Power, structures, propulsion) that you can tune and modify quickly to fit the mission profile.
Presumably, a lot of the work to streamline the process of designing the bus and plugging in instruments could be easily translated to space science missions, and if a future opportunity like this were available we could do exactly that. Of course, you'd have to have a pretty interesting guidance system and a very robust structure, since you'd only get an advantage if you stuck the probe in the asteroids path and let it slam into it to get the momentum.
The optimist in me says that will make the killing of the DRM that much faster. Recall that its because Apple got themselves into such a good position that you had the flood of DRM-free music that began with (oddly enough) Amazon*. Assuming Amazon doesn't roll over to every demand of the publishers then they'll eventually grow tired of having to put up with Bezos, and if the Kindle ecosystem has enough market share, the only way to penetrate it will be to go DRM free.
My concern is actually that Amazon won't have enough of the market to force the same situation, and that competition between the Sony and Amazon formats will strangle the market again. Even worse, Sony could come out on top and who knows what ridiculous convoluted scheme they'd push the market into.
To make the counter-argument, I'd argue that you can get more value out of buying a book over checking it out, encouraging people to buy books they feel a strong connection to, need to mark up, or intend to use for long periods of time. However, without some form of DRM, you can't check out an eBook... once you get it you have it forever. Then, there's no reason for anyone to check out an eBook instead of actually buying it, and the only way to make money off of it is to rely on selling the physical copy, and there's no point for having the digital version.
Note that I'm not arguing that we need DRM. Instead I'd say we should hope to have a hybrid market of both physical and digital books. If you just want a digital book you'll have to buy it, but there will still be physical libraries with physical books that you can borrow for free. Really what digital books do in are crappy consumer paperbacks. Another aspect of that market is that if there is a book you want to own a nice physical copy of, in either trade paperback or hardback form, when you buy it you get a free digital copy as well. At least that's my opinion as a Kindle owner who's checked out more books than I can remember from the library in days past.
It's already been done.... there are converters for *.lit, it reads *.txt just fine, and it also reads *.mobi all on its own (*.amz is just a slight modification of it). The only time you have trouble is
a. the publisher has a non-Amazon form of DRM on it. b. its a PDF or some other non-reflowable format.
There are even a few ways to get it on... email it to the Kindle's email address, load it over USB cable (it acts just like a flash drive), or put it on an SD card. Now, if you want to get an Amazon-DRM'd book onto something else thats a different story.
I agree. It's not so much that I didn't have anything to do but more that what I was doing was sitting outside trying to get a telescope working. A comet on its closest approach is much more interesting than flipping back and forth between Sirius and M42.
(I'm working more on technology applications rather than the actual astronomy, explaining why I was out with a telescope last night but not paying too much attention to astronomy news.)
Currently, there are times in the US when electricity is sold wholesale for close to a dollar a kilowatt during peak usage or times of emergency when power needs to be shipped around the national grid. Sage said SBSP will never be cost comparable with the current going rate of 6 or 7 cents a kilowatt due to the enormous set-up costs.
Whenever I see space-based solar power I never believe its economically viable. Based on that quote, they recognize that its not viable in the current market, and that average energy costs would have to increase by a factor of 15 to 20 times in order to make it viable. They think that the trends in energy cost are going to go that way. Somehow, I think as energy costs increase we'll get more creative on the ground, expanding ground based solar power, wind, nuclear, geo-thermal, etc., improving efficiency and developing new technologies to bring those costs back down.
As others have pointed out, launch costs are the critical, incredibly expensive aspect. In order to make it practical, we need to drastically reduce the access cost for space, by at least an order of magnitude. None of SpaceX's most optimistic estimates, or anyone elses, make it more viable.
However, there is a practical path for development of SBSP in military applications. A few satellites and some trucks with microwave receivers on the back are very appealing when compared with the current method for generating battlefield power: supply lines hauling in diesel fuel to power good old-fashioned generators. SBSP has great tactical advantages, and may actually be comparable in cost as well. From here, we may very well see it gain civilian applications as well.
I'm guessing its basically just a star-tracker algorithm. I've taken a class on it, but its probably the thing I understand and remember least since I've been in grad school. Basically, they pick out the bright stars, and measure their locations to sub-pixel precision through centroiding, so you're working on a set of coordinates, not an actual image.
Then an algorithm cycles through a star catalog to compare the relative positions and identify the stars. In this case, since the angular size of a pixel is unknown; this has to be figured in as an unknown as well. Unfortunately I can't say how that works, I do know one guy who did his dissertation on a new search algorithm that reduced the computational cost by an order of magnitude.
Really, if you're interested, do a literature search on star tracker technology.
Slashdot Mirror
From what I can tell in a brief skim, it really does pose a fundamental limit given current technology. The problem is that with the largest mirror we can imagine getting up into space, and with the highest sensitivity sensors, the signal-to-noise ratio is still too low to get a usable measurement without taking hundreds of measurements.
They plan to detect the chemicals in the atmosphere by measuring the absorption bands in the starlight as some of it passes through the atmosphere. This is presumably going to be a lot more sensitive than trying to detect the light from the planet directly, since you have a lot more photons to carry the information. The signal to noise ratio in this case is really limited by the unfortunate fact that light energy is discretized and you can't make finer measurements than a single photon. Thus a large mirror with a high-quantum efficiency (95%) sensor, is really the best you can do.
The only hope to improve this is to either get bigger mirrors, which really depends on improving space access and is unlikely to give order of magnitude improvements, or to implement an as yet unrealized method that is able to get more information. If it were a problem of angular resolution there are plenty of interesting tricks you could use to improve it. Unfortunately I can't think of anything better, and it doesn't seem anyone else has yet either. Of course, that doesn't mean no one will... but its not as simple as just designing the next mission.
Actually... random 3:30 am idea... if you did something in thermal-IR, and measured the absorption of the blackbody emissions of the planet by the atmosphere you might be able to get something working. The intensity would be a lot lower than looking at the stars light, but the dimming due to absorption would be much larger percentage-wise... although it would take some heavy math to show if it would actually give you a better SNR. Of course, there are plenty of holes here: among other things, my knowledge of atmospheric chemistry and absorption is very limited, and this would all depend on being able to resolve the star separate from the planet, and would thus rely on some complicated interferometric methods....... and you'd have to block out the star light to be able to get the planet light as anything more than noise... and probably the number of photons in thermal IR from a planet are too low to be able to even see it on its own... but maybe I'm wrong and it could work, or something else can.
I think if someone had a solid path to go down for developing FTL travel they would have no trouble finding funding. In fact I think that would have the effect of encouraging more missions like Kepler, so we would have good places to go once we got it working.
I'd venture a guess (I'm not involved in anything similar to that kind of physics) that the kind of results that would lead to a radical new form of propulsion wouldn't come from a heavy focus of funding, but rather continued support of seemingly impractical physics research in many or all directions.
Heavily directed funding is great for improving the efficiency, reliability and capabilities of current ideas, but can't really lead to the kind of radical breakthroughs FTL would require. A nice succinct quote from the West Wing TV show: "If it was up to the NIH to cure polio through a centrally directed program, you'd have the best iron lung in the world but not a polio vaccine."
I don't think the idea is to find a new place for us to live. Obviously, our ability to take advantage of such a planet is incredibly limited.
Rather, its to understand what the possibilities for life outside our planet are. Putting it in simplest terms, its working to get experimental data for some of the coefficients in the Drake equation.
Unfortunately I think coming up with something truly new to do with high-school level equipment and a teacher's who doesn't spend a lot of their time doing research might be difficult.
That said, rather than trying to do new science, contributing to experiments and observations in a way thats more involved than Folding@Home would be easier. My recommendation, because it's something I'm working on right now, is asteroid hunting. A decent robotic observatory with a ~3-4" scope can do it quite well. If you could find a local person who has a respectable setup and would be willing to donate a few nights on their equipment, it would be pretty straightforward.
During the day you'd have the students pick out a dozen or two dozen sky segments, submit plans to the robotic site to image each section a couple of times, an hour apart. You get the pictures back the next day in class, compare the results and see if there are any moving objects in the field of view. If so, you've found yourself an asteroid. After this you can pick out its angular location from the known picture location, and with the time you can pick out its trajectory and compare it to databases that are out there, chances are good you'll have found something new. I know there are some articles on the internet that give better information, I'm still looking to set it up for a scope I'm working with. Also the chance of finding an asteroid is supposedly about 1 in 6 from any particular sky region.
Fair enough, although someone is telling us we can't. Maybe an overambitious local FAA office, maybe DHS, maybe the school administration. I'm guessing its similar regulations that we have to deal with for UAV's. Also, we're based out of College Station, TX and have a limited budget, so we can't go all the way out to White Sands or somewhere similar. We're right between Houston, Austin, and Dallas, and the area around Waco hasn't been usable for the past 8 years because of Bush's ranch. It's really an annoying area to deal with. We also do spend quite a bit of time getting the permits to fly, still limited to a mile altitude.
So while I'm not sure on where all the restrictions are coming from, we keep getting more and more restricted in what we can do, and although there are ways to get around many of the issues, our budget isn't big enough to allow us to do those things. I think Armadillo does most of their higher altitude testing out in Oklahoma, which is really outside of our practical range, although that is a good suggestion. I actually know people there, but haven't talked to them about these particular problems, I finished being directly involved a while ago.
While some simple licensing might be in order, in my experience the government is severely, ridiculously restricting model rocketry right now. For our senior design class we build ~150-lbf hybrid rockets that reach a mile in altitude (reasonably limited by the FAA in moderately dense airspace).
We've always had some restrictions, mostly from the school and the FAA. The school doesn't let us build our own solid motors because of safety, and we have to go through a lot of paperwork with the FAA to schedule launches. We had to move from our old launch site because it was pretty close to Crawford, TX. Lately (as I commented before) they've cracked down on guidance systems, which I think is crossing a line, but is at least within the realm of being reasonable.
Just this year, though, Homeland Security has gone to a new level of ridiculous, informing the advisor that the project now fell under International Trade in Arms Restrictions (ITAR). WHat this implies is that we can't tell any foreign nationals what we do... if there's a foreign student on the team they're not allowed to see any of the old classes materials. I was working to post a lot of information on the wiki for a student organization with a lot of chapters that do similar scale rocketry, showing our designs, the design equations, what equipment we've used, testing equipment, etc. Only now, I can't do that because if I did I'm afraid I'd bring legal trouble onto the organization which really doesn't have the resources to deal with it. So instead of being able to work collaboratively we're stuck recreating the wheel most of the time.
Bypassing the fact that ITAR is a noose thats going to tighten on the US space industry eventually, I find it amusing that a project developed by a bunch of undergrads could possibly pose a threat to proliferating missile technology. The rockets that fly out of Gaza on a regular basis seem to able to fly much further than ours, and are probably much more robust, practical designs, since ours tend to go in a 'I wonder if we can do this?' kind of direction. I'm also pretty sure they'd be happy to share their knowledge with plenty of the people we're worried about spreading the technology too.
In addition to not being a trivial exercise, the Feds tend to view building a guidance system as going beyond model rocketry to building a guided a missile, which they frown on. You might be able to get away with very small ones, but I don't really have a good feel for what the minimum weight you could get for servos, control computer and sensors would be, and what size rocket that would indicate.
We build ~150-lbf thrust hybrid rockets for our senior design projects, and in the past few years its become more and more difficult to do anything interesting because of increased restrictions, from the school administration, the FAA, and Department of Homeland Security. Having a launch site that was pretty near Crawford, TX also made things difficult, had to find a new launch site.
One of my friends, who works at a satellite design company, was debating another employee on some aspect of the thermal design for a top-level systems design, using some data from a book called "Space Mission Analysis and Design" (SMAD). At this point the other guy corrects him pointing out the limitations of the table he was using, then tells him to look at the beginning of the chapter. Turns out the guy he was arguing with had written the thermal control chapter.
Although he does seem to be a bit of an ass about it, there is a distinct non-linearity between GPA and ability. While I would never claim grades don't matter, I wouldn't trust the design work from anyone in my department who's doing better than about a 3.8 in undergrad. (I'm about to graduate with a masters in Aerospace Engineering.) Not to generalize too much, but the ridiculously high GPA students tend to be completely incompetent at any practical applications, and also are fairly obnoxious because they don't recognize their limits and tend to assume they're better than everyone else. Of the few I've known in our department there's only one that I have much respect for.
Beyond that, (again generalizing, I apologize), people who are in the 3.4-3.8 range (where I am) are going to be much better at theoretical analysis and systems level work, while when you're designing a part to be sent to the machine shop I'll take the guy with a 2.8-3.4 who worked in a machine shop through high school any day.
Really, what I think, and what I've heard from some interviewers I've worked with on internships is that what projects you've done, and what roles you played is the most valuable indicator of how you'll do. Of course, anything below around a 3.0 does rightly raise questions about commitment (but shouldn't be a deal-breaker).
Actually, I agree with you, even if Dr. Gates doesn't. The real problem with the F-22 right now is that for whatever reason (it could be a good one or not, I don't know), its being cast as either we make them all now, or just let the whole program go. Really what would be the best way to go in my mind is to simply spread out the production, defraying the costs and allowing us to pay for and prosecute the current conflicts while not completely halting development on future systems.
I think in addition to your reasoning, it simply comes down to the fact that the past 15 years have been a very unipolar world, where all conflict is by necessity asymmetric. However, with the tides swinging away to a highly multi-polar world, more conventional conflict and peace-keeping/counter-insurgency will both have to be accounted for, and as such research needs to be directed in both directions.
That said, I have a lot of respect for Dr. Gates (I attend Texas A&M where he was president until he took SecDef), and I think a lot of his position here is simply a counterbalance to the pie-in-the-sky overreaching of Rumsfield. I'm certain he's not so shortsighted as to completely ignore the future for the sake of the present.
Also today, a judge struck down the gay marriage ban in California in 2005, Karl Marx died in 1883, Albert Einstein was born in 1879, and the first town hall meeting in America was held in Faneuil Hall in Boston in 1743. So maybe we should all mourn Marx and the way his theories were manipulated/failed in the Soviet Union. Or maybe we should all celebrate Einstein by riding on very fast trains and shining lasers at each other. Or celebrate New England-style democracy. Celebrate a victory for gay rights or mourn your family values as the case may be.
There are a lot more important events in history than there are days in the year. And to be honest, most of history is pretty depressing, with plenty of horrible things happening... if we insisted every day on remembering all the terrible things that have happened, it would get very old very fast, and I imagine you'd see an upswing in suicide statistics. Learning from the past is important, but insisting on dragging down every day by revisiting it is absolutely ridiculous.
You're right, it wouldn't be useful for a full, conventional conflict with a country like China or Russia, or even pre-invasion Iraq. However, since the fall of the Soviet Union we've been much more involved in police action (the Balkans, Somalia) and insurgency fighting (Iraq and Afghanistan). When they say safe from missiles, they mean safe from shoulder mounted rockets that can devastate helicopters, low-flying aircraft, and any aircraft on take-off or landing. Having something that high with 10 years aloft means that its safe in this style of modern warfare.
Also, while minute-by-minute persistence, what you get from this, is much more important in this kind of asymmetric warfare. Fighting a conventional battle with a large army involves tracking troop movements and other large-scale things that are hard to hide from a satellite. However, for finding insurgents in Baghdad or tracking fighters crossing the border between Afghanistan and Pakistan, persistent observation where you can follow an individual's or small group's movements is much more valuable.
The current Secretary of Defense is very big on fighting the current wars instead of developing more cold-war relics like the F-22, so this seems right in line with his priorities, and it makes sense. If it were intended for spying on US cities, they would be trying to keep it much quieter and, as others have pointed out, it wouldn't really be impossible to see the airships. Given the (correct) uproar over the NSA wiretapping, which only focused on phone-calls going out of the country, I can only imagine how quickly such a program would be brought down, especially given how much harder it would be to hide.
As someone who's grown up in Oklahoma and Texas (kind of southern, kind of midwest), sir and ma'am do indicate respect, but not solely subordinate-to-superior. As often as not, it can also be used as a sign of mutual respect between equals, which does, I feel, go along with the American egalitarian ideal.
As far as our tendency to elevate public servants to positions of authority over us, I can understand the confusion. I think it's a general extension of republicanism (small-r), where we elect people to rule us, placing them in authority even though we know in the end, they're subservient to the people.
Beyond that, while we do value our freedom, we also tend to take comfort in order and the rule of law. I think that also helps explain our near-religious adherence to our Constitution: by holding to it like we do we're able to sustain an effective government and a strong sense of law and order while maintaining our freedom and growing more equal over time (yes I'm aware we do screw it up sometimes). I read somewhere that in France they say that in America, the people are afraid of the government, while in France, the government is afraid of the people. I think these odd habits of ours are related. If I remember correctly France has had 7 or 8 revolutions and changes in government systems since we instituted our system... in their minds, if the government gets too powerful and oppressive its high-time for a revolution. Here in America though, we've stuck with our system for quite a while and see it as something more than mere laws, its part of who we are as a people, and gives an overriding sense of stability and the rule of law. We're scared of giving the government more power than what it has because the idea of replacing the system is almost unimaginable.
I hope my ramblings make some sense of our point of view... obviously its not perfect, but it works pretty well for us.
Different kind of privacy. Some things, like health conditions, SSNs and credit card numbers, you don't want the government, corporations, insurance companies or identity thieves to be able to mine out of large databases or find in a deep background check. Other things, like your affinity for bodice-ripping novels or the fact that you secretly love the latest Britney Spears or Backstreet Boys (are they still around?) CD are things you just don't want to advertise as you're sitting on the bus or waiting in line.
Personally, I just prefer the convenience of e-books. While I do like that you can read one-handed, its because the single thing I hate most about real books is trying to hold them open while you're eating and reading at the same time.
My apologies. I'm not an expert on e-ink technology, my personal field of study of dynamics and control of space systems.
All I was doing was letting others know of my first-hand experience, and the biggest issue that I've had. While I may have been imprecise in my language, since I have no reason to state that you are incorrect, and wikipedia seems to corroborate you, I do know that the screen in the Kindle (which is also the same screen as the Sony PRS-505), is manufactured on glass backing. This was probably selected for structural and weight issues, but I wasn't involved in that so I can't say for sure. At any rate there are many examples of the screen backing shattering under direct pressure.
There are a number of issues where I can be accused of being in a bit of a fantasy world: I believe in God, I have hope there's life on Mars, I still believe in a small government after 12 years of so-called republican rule, and hell, I still secretly believe that a space elevator can work. However, in this case, I was just relating my own experience, and I have trouble seeing how I displayed any predilections towards unicorns, or really anything but a lack of knowledge of display technology.
So... my recommendation, quit the trolling. You could have just posted a correction, pointing out where I was wrong. I would have looked into it more, and learned something for the day, as might other people reading the thread. Instead, the biggest thing I got is a reminder that the world is full of assholes, and that they're not scared to come out on the internet.
Then don't buy it. If its usage doesn't appeal to you, then don't buy it. It doesn't change the fact that its expensive because of eInk, and it doesn't change the fact that some people decided it was a major selling point. I for one find it incredibly pleasant to read of off, and I like to read long-form novels, so it works wonderfully for me.
That's the great thing about having an open market, you can use what appeals to you. I personally like to tinker, so I have linux on my desktop and server, but want a laptop that works all the time, so I use a Mac there; if someone else uses Windows it doesn't bother me at all, as long as they don't expect me to as well. I also really like Dr. Pepper, that doesn't mean everyone has to agree with me. Some prefer coke, or diet coke, or even just drink water, since it is quite a bit healthier... as long as theres enough of a market the DP keeps selling it, it just doesn't bother me much. No need to belittle a product just because its something you wouldn't use.
From experience with the Kindle 1, which I've had for ~ 6 months, its a very durable device with the exception of direct pressure on the screen. I've accidentally spritzed it with water and soap, so as long as you're not giving it a bath it does fine. I stick it in my backpack on the way to school and takes a fair amount of abuse that way.
However, the one sticky point is that the screen is very susceptible to direct pressure on the screen. Because the e-ink relies on a glass backing for its operation, if you lean too heavily on it, it will shatter and the screen will be non-functional. This happened to mine when I had it on my bed and it disappeared under some blankets and I put my palm down on it crawling back into bed. Fortunately, I had a very good experience with Amazon customer service and received a new one within a few days. Keeping it in its leather carrying case and being aware of it eliminates those problems for the most part, and it can take quite a bit of abuse with just minimal precautions.
With how thin the new version is, and the fact that the case doesn't come standard, I wonder if the screen isn't more durable on Kindle 2. Can't say I'd want to test it myself though...
Without any actual analysis, I'll go out on a limb and estimate it would cause as much havoc as any large man-made piece of junk out there, like say a dead Soviet satellite. A much larger asteroid would be a different story, since not only would it have a larger footprint, but would also have hard-to-predict gravitational effects on all the satellites that got too near it. Of course, we're doing a pretty good job of detecting larger NEOs now... Apophis is the most problematic, mostly because we simply don't have high enough precision knowledge of its position to know where it will be in 2029 and 2036.
While you're absolutely correct, there is a program known as Operationally Responsive Space (ORS) thats being headed up by DoD rather than NASA that is headed in that direction. I think the time-frame they're considering is closer to 2 weeks, but the general idea is to be able to recognize a need, and design, construct and launch a mission in that period of time. That includes getting adjustable plug-and-play parts (GNC, Power, structures, propulsion) that you can tune and modify quickly to fit the mission profile.
Presumably, a lot of the work to streamline the process of designing the bus and plugging in instruments could be easily translated to space science missions, and if a future opportunity like this were available we could do exactly that. Of course, you'd have to have a pretty interesting guidance system and a very robust structure, since you'd only get an advantage if you stuck the probe in the asteroids path and let it slam into it to get the momentum.
The optimist in me says that will make the killing of the DRM that much faster. Recall that its because Apple got themselves into such a good position that you had the flood of DRM-free music that began with (oddly enough) Amazon*. Assuming Amazon doesn't roll over to every demand of the publishers then they'll eventually grow tired of having to put up with Bezos, and if the Kindle ecosystem has enough market share, the only way to penetrate it will be to go DRM free.
My concern is actually that Amazon won't have enough of the market to force the same situation, and that competition between the Sony and Amazon formats will strangle the market again. Even worse, Sony could come out on top and who knows what ridiculous convoluted scheme they'd push the market into.
To make the counter-argument, I'd argue that you can get more value out of buying a book over checking it out, encouraging people to buy books they feel a strong connection to, need to mark up, or intend to use for long periods of time. However, without some form of DRM, you can't check out an eBook... once you get it you have it forever. Then, there's no reason for anyone to check out an eBook instead of actually buying it, and the only way to make money off of it is to rely on selling the physical copy, and there's no point for having the digital version.
Note that I'm not arguing that we need DRM. Instead I'd say we should hope to have a hybrid market of both physical and digital books. If you just want a digital book you'll have to buy it, but there will still be physical libraries with physical books that you can borrow for free. Really what digital books do in are crappy consumer paperbacks. Another aspect of that market is that if there is a book you want to own a nice physical copy of, in either trade paperback or hardback form, when you buy it you get a free digital copy as well. At least that's my opinion as a Kindle owner who's checked out more books than I can remember from the library in days past.
It's already been done.... there are converters for *.lit, it reads *.txt just fine, and it also reads *.mobi all on its own (*.amz is just a slight modification of it). The only time you have trouble is
a. the publisher has a non-Amazon form of DRM on it.
b. its a PDF or some other non-reflowable format.
There are even a few ways to get it on... email it to the Kindle's email address, load it over USB cable (it acts just like a flash drive), or put it on an SD card. Now, if you want to get an Amazon-DRM'd book onto something else thats a different story.
I agree. It's not so much that I didn't have anything to do but more that what I was doing was sitting outside trying to get a telescope working. A comet on its closest approach is much more interesting than flipping back and forth between Sirius and M42.
(I'm working more on technology applications rather than the actual astronomy, explaining why I was out with a telescope last night but not paying too much attention to astronomy news.)
Whenever I see space-based solar power I never believe its economically viable. Based on that quote, they recognize that its not viable in the current market, and that average energy costs would have to increase by a factor of 15 to 20 times in order to make it viable. They think that the trends in energy cost are going to go that way. Somehow, I think as energy costs increase we'll get more creative on the ground, expanding ground based solar power, wind, nuclear, geo-thermal, etc., improving efficiency and developing new technologies to bring those costs back down.
As others have pointed out, launch costs are the critical, incredibly expensive aspect. In order to make it practical, we need to drastically reduce the access cost for space, by at least an order of magnitude. None of SpaceX's most optimistic estimates, or anyone elses, make it more viable.
However, there is a practical path for development of SBSP in military applications. A few satellites and some trucks with microwave receivers on the back are very appealing when compared with the current method for generating battlefield power: supply lines hauling in diesel fuel to power good old-fashioned generators. SBSP has great tactical advantages, and may actually be comparable in cost as well. From here, we may very well see it gain civilian applications as well.
I'm guessing its basically just a star-tracker algorithm. I've taken a class on it, but its probably the thing I understand and remember least since I've been in grad school. Basically, they pick out the bright stars, and measure their locations to sub-pixel precision through centroiding, so you're working on a set of coordinates, not an actual image.
Then an algorithm cycles through a star catalog to compare the relative positions and identify the stars. In this case, since the angular size of a pixel is unknown; this has to be figured in as an unknown as well. Unfortunately I can't say how that works, I do know one guy who did his dissertation on a new search algorithm that reduced the computational cost by an order of magnitude.
Really, if you're interested, do a literature search on star tracker technology.