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+ - Possible collision between cube-satellite and old space junk

Submitted by photonic
photonic writes "The BBC is reporting about a possible collision between Ecuador's first satellite (a small cubesat) and debris from an upper stage of an old Russain rocket. If confirmed, this might be the 3rd case in recent years, after a high-speed collision of an Irridium satellite with a dead Russian satellite in 2009 and a collision earlier this year between a Russian laser reflector (which can be tracked very accurately) and a tiny piece of a debris of a Chinese weather satellite that was destroyed in a missile test."

Comment: Phonesats (Score 2, Insightful) 85

Congrats to orbital, even though launching a new rocket assembled from parts built by Russians by a company that is already working in the space business for many years seems a small accomplishment compared to what SpaceX pulled off. As is common on a first flight, the main payload is an instrumented dead weight. The coolest thing about this mission is IMO some small cubesats they launched as secondary payloads. These are some super cheap phonesats built by NASA, which are powered by a Nexus One or Nexus S. Data packets that could be received via amateur radio should hopefully appear here soon.

Comment: Flightradar24 (Score 4, Interesting) 27

by photonic (#42486183) Attached to: Visualizing Personal Flight Data With OpenFlights.org
Neat plots, but I find the real-time and historic plots of actual GPS tracks shown at Flightradar24 much more fascinating. Most European flights have an ADS-B transponder on board, which basically is a radio beacon that transmits a GPS position. These signals can be received by anyone with a cheap USB receiver over a few 100 km. For these planes, the position is plotted online with a delay of only 10 seconds or so. American planes seem to lagging behind with adoption of this system. I can watch this site for hours to see what airplane flies over my house, to see how airplane are holding in case of bad weather, to see when I have to pick up friends from the airport, ...

+ - Man extradited to the US after uploading child-pornography to MS SkyDrive->

Submitted by photonic
photonic writes "The national Dutch broadcaster reports (Google translate fails due to cookie warning) that a man living in Amsterdam was extradited to the US for the production of child-pornography. The man is a US citizen and the offenses were allegedly committed in the US and other countries, so the extradition seems uncontroversial. The interesting detail is that the man was apparently caught after he uploaded some of the offending files to Microsoft SkyDrive. Are the authorities actively scanning all your files or do they simply give Microsoft (and Dropbox, Google, ...) a list of hashes of known illegal material?"
Link to Original Source
Science

+ - Quantum gas goes below absolute zero ->

Submitted by mromanuk
mromanuk writes "It may sound less likely than hell freezing over, but physicists have created an atomic gas with a sub-absolute-zero temperature for the first time. Their technique opens the door to generating negative-Kelvin materials and new quantum devices, and it could even help to solve a cosmological mystery."
Link to Original Source

Comment: Money back for consumers? (Score 1) 153

by photonic (#42192953) Attached to: EU Issues Largest Antitrust Fine to Date for CRT TV Price Fixing
The EU has many issues, but prosecution of anti-competitive behavior is one of the areas where they shine. I bought a big Philips 'flatscreen' (i.e. the front is flat, it sticks out half a meter on the backside) for around 1200 euro circa 2001, so can I now claim some of my money back? (Related bonus question, since this is Slashdot: A somewhat obsolute piece of electronics weighing 50 kg is collecting dust in my living room. It is still working perfectly, but has only scart and analog coax inputs. Resolution is also on the low side, it is not HD. Any useful project it can be used for, other than throwing it out of the window to kill my neighbour's cat?)

Comment: Re:$1500 for a 1366x768 TN display. (Score 1) 403

by photonic (#42133009) Attached to: Dell's Ubuntu Ultrabook Now On Sale; Costs $50 More Than Windows Version
Exactly, came here to say the same. I have a Dell Latitude 5420 running mainly ubuntu, which cost me around 1000 euro total. During ordering, you can customize it a bit: I went for one of the cheaper I3 processors, but upgraded the screen from standard 1200x800 or so to 1600x900 without even thinking. The 50 euro for the upgrade of the screen is very good value for money. Having some pixels to spare is essential when you want to open 2 editors side-by side. It looks pretty good compared to my colleague's non-retina last generation's macbook.

Comment: Fine grained options (Score 2) 277

by photonic (#41852633) Attached to: More Than 25% of Android Apps Know Too Much About You
They should add more fine-grained permission, so that for example an application would only require 'access to add-server' instead of full network access. And please make some clear policy that gets enforced, i.e. applications that do ask more permissions than they need get banned until the problem is fixed.

Comment: Re:3 days to ISS? (Score 1) 111

by photonic (#41589741) Attached to: SpaceX Dragon Set To Launch
That is BS. IANARS, but the orbit that supply- or crew-vehicles sent to the ISS are launched on is probably the equivalent of a Geostationary Transfer Orbit, except that you want to end up in the low-earth-orbit of the ISS instead of the geostationary one. This means that they are launched more or less on an elliptic orbit, with the high point of the ellipse intersecting with ISS's circular orbit. At this high point, you do a 'circularization burn', after which you are at the same height and same speed as the ISS. I am for sure skipping over some details, such as orbital inclination, but there is no fundamental reason why you can not launch at exactly the right time so that you are really close to the ISS just after this burn.

One reason why it takes several days might be due to launch inaccuracy: there are always small errors in the orbital parameters just after launch, so you probably want to allow for some time to adjust the orbit with small burns. Another reason might be procedural, you might want to do some potentially dangerous checks of your vehicle before you come close to the ISS. As an example of how short a rendezvous can be, the Russians recently launched and docked a Progress freighter in six hours (instead of the usual 2 days), they plan on doing this in future with the manned Soyuz.

Comment: Re:I freeken love this. (Score 4, Interesting) 62

by photonic (#41420053) Attached to: All Over But the Funding: Open Hardware Spectrometer Kit
Optics guy here too. I don't know a lot about spectroscopy, but I had to assemble a spectrometer for my thesis project. It was a pretty fancy imaging spectrometer (main element was a concave mirror and grating combined in one) and used a LN-cooled CCD as the sensor. This was not cheap stuff (~5000eu for the spectrometer and probably > 20000eu for the camera), but the operating principle is exactly the same as the DVD + webcam. The resolution was limited to around 1 nm due to the input slit, not sure if they could improve things by using a slit in this home-built device. I had to calibrate it from scratch, which was actually pretty easy: I borrowed some spectral lamps from the 1st year lab course and also used a HeNe-laser we had laying around. Choose a few of the big lines (which should all be known to better than 1 nm) and for each write down the pixel position of the line on the CCD. Perform low order (e.g. quadratic) polynomial fit and you are done calibrating. I don't know if there are some cheap spectral lamps that you could use at home, there is at least the yellow lines from the Sodium (?) street lightning. I agree with others that the resolution of these home built devices is probably too low to identify materials, but it is for sure a fun project.

Comment: Re:stupid article is extremely stupid (Score 1) 452

by photonic (#40982049) Attached to: Could You Hack Into Mars Curiosity Rover?
Maybe just point it at Mars? The diffraction limit is your friend: with a wavelength around one cm, a 100 meter dish has the a diffraction limit (~wavelength/telescope diameter) about one order of magnitude worse than your 50 euro plastic telescope for kids (which might just resolve some white spot at its poles). From back of the envelope calculation, I would guess that the width of the radio-beam is pretty similar to the diameter of mars itself.

Comment: Re:Gasoline-like energy density (Score 1) 582

by photonic (#39749183) Attached to: IBM Creates 'Breathing' High-Density Lithium-Air Battery
Because your laziness of saving 2 seconds would easily cost you more than 10% in efficiency. That would be like filling your car with gasoline and not giving a shit that you spill large amounts of fuel just because you are to lazy to properly connect the hose. WIth both fuel and electricity prices remaining high for the forseable future, efficiency will count till the last percent.

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