Oh my god how do 90% of the replies blow this so out of proportion???
Yeah, it is some 5kg of "litter" if you want to call it that. How much litter is thrown onto train tracks on a normal train station in one day? Will enthusiast jump after it to return it to some organisation?
Yeah, the paths of these "seeds" might cross some air plane or some person on the ground but it is highly highly unlikely. Ever wondered why nobody is hit by rocket parts on new year's eve? It happens but rarely enough because human heads cover such a low percentage of earth that it just doesn't matter even with billions of private rockets shot every year.
Indeed rockets landing on people do happen, happened too me, though at the stage the fall most of the time (like nearly all) have already burned out and just a stick that hits you on the shoulder and you think a bird has shat upon you it is just so low impact. Least the one that bounced of me. But your spot on the odd's are low and even then the chances of it causing damage are low. It is the ones that go off incorrectly at angles into the crowd that people worry about and with that one bad rocket at a public display - it happens. Still if these seeds when deployed clump up, gain moisture and freeze together into a large ball of ice and seeds - then it could be most epic a landing.
The Dropion is retrieved and so is the first stratoseed. We are guessing that the fierce temperature was not taking it easy on the GPS trackers. But it seems that other seeds might have survived it as well. I'll keep you posted. Pavel Kasik, Technet.cz
So far, two stratofeeds have been found. The others did probably not survive the severely low temperature in the stratosphere. Those can still be found, of course, but in the "hard mode", without the assistance of GPS location. At least 200 people (more than 100 cars) are at the location of one of the two retrieved stratoseeds.
So far, four stratoseeds have been found, some of them by pure chance :-) We are officially closing the game at 6pm (UTC+1), but people can obviously still search for the stratocaches - there will be some prizes for late explorers as well. We are now reviewing the video from the two GoPro HD cameras - I have to say, it looks pretty spectacular. We hope to bring you the video on Monday. You can ask me any questions in English through messages to our FB page https://www.facebook.com/TechnetCZ.
For anyone wondering what's normally attached to a weather balloon, reading up on the history of the Radiosonde[1] is pretty interesting.
Things like thermal insulation, choice of materials for biocompatibility/minimal long-term hazard etc are all important parts of the design.
There's a fairly in-depth tear-down and explanation of the bits of one by Mike Harrison online[2]. The battery tech used there is particularly neat IMO.
I volunteered for a research group that did amateur balloon launches like this in college. Our payloads were about 8 pounds and were regularly sent to 30k meters/100k feet before a cutdown command was issued. I don't remember ever measuring how far the package would get from the launch site when it reached maximum altitude, but the package could pretty easily travel 100 miles from its launch point to the touchdown location.
Here's the site if you want to learn more - they've got some neat flight data posted if you're interested.
idnes.cz is the web presence of the "largest serious Czech newspaper", as they like to call themselves. Proud to see this on top of HN. Geocaching is fairly popular in the Czech Republic, though I don't know of a comparison to other countries.
This is a really cool idea. I can see it being a fun family outing trying to find them and a good way to introduce kids to the tech involved. Anyone know what the cost was for the project?
The Dropion (+high-altitude balloon) was a "registered flight" so the air traffic control (or, specifically, Urad pro civilni letectvi) knew about this experiment. And then the seeds falling dow are really slow and light.
I was looking into that a while ago. There are multiple categories based on balloon size, weight of equipment. They are mostly concerned and the strength of the string between them.
Away from airports, the smallest balloons as completely unregulated, bigger ones need to be reported. Even bigger ones need a schedule. My overall impression was that all the rules were reasonable amateur-friendly.
Here is an interesting video where you can see how they are testing jet engines before they can be certified for flight - they chuck various stuff inside including dead birds: http://www.youtube.com/watch?v=_jfXX7qppbc
The app was only one (a bit unreliable) way to play. Fortunately, there are other ways. Most players just used the up-to-+date info from the website. or they were lucky to find those malfunctioning stratocaches by chance, e.g. on the field.
Don't get me wrong, the idea is cool, but I think there's enough plastic garbage on earth already without dropping more from space. Who cleans those things up if they land on private property?
The owners of the private property or those willing to enter private property to retrieve the object. The whole point is to find those "things", so I doubt they will end up as plastic garbage.
There are only 12 objects that are GPS tracked and twelve thousand people is searching for them right now. I do not think littering is any problem here.
Yeah, it is some 5kg of "litter" if you want to call it that. How much litter is thrown onto train tracks on a normal train station in one day? Will enthusiast jump after it to return it to some organisation?
Yeah, the paths of these "seeds" might cross some air plane or some person on the ground but it is highly highly unlikely. Ever wondered why nobody is hit by rocket parts on new year's eve? It happens but rarely enough because human heads cover such a low percentage of earth that it just doesn't matter even with billions of private rockets shot every year.