dylan604
yesterday at 4:54 PM
We did a similar thing, only we intentionally made it more difficult on ourselves by launching at sunset because we were hoping to grab the view of city lights at night with the GoPros. Also, we did not have any licensed radio operators in our group, so no fun equipment like that. We instead depended on a consumer GPS tracker that updated once ever 5 minutes. We also had an Arduino with various sensors attached, but that was for me as the main purpose was the video footage.
Some of the memorable experiences from it:
1) Purchasing equipment to do a Hydrogen launch because this was during a Helium shortage and the cost difference was significant. Arrived at store to pick up our Hydrogen tank where the guy working took a look at us knuckleheads and had serious reservations about selling us inexperienced dorks Hydrogen. Took pity on us and swapped out all of our fittings (hydrogen fittings are specific to prevent accidental use of hydrogen) and sold us the tank of Helium for a much cheaper price than what we were originally told.
2) Printing up stickers to attach to the payload box with "If Found" contact instructions only to realize one second after letting go of the payload that you forgot to attach said stickers.
3) The terror of realizing that when the balloon took off that it immediately headed west when the flight predictions you had been running for the previous days before all showed the balloon landed east.
4) Having to contact ATC to report the launch of the balloon, only to be told they needed further updates at every 10,000' feet.
5) The terror setting in deeper when the consumer GPS unit stopped responding after 30,000' altitude and then having ATC scold how unprofessional we were for using cheap devices. At least they told us they were still tracking it.
6) The shenanigans a group of knuckleheads got up to waiting the ~3 hours for the balloon to land.
7) The relief when the consumer GPS unit started pinging updates again on the way down and the laugh (with us not at us) from ATC that we could start reporting back again.
8) Using mobile Google Maps to attempt to find the GPS location. Wandering around fields in the middle of the night to find a strange circular pattern of out of place plants to realize it was from a deer feeder's throw. Then searching for the nearby camera trap to wave to leave some hunter with serious WTF.
9) Nearly giving up on the search until deciding to use the hotspot to look up the GPS coordinates not on a mobile device to see that the balloon was less than 300' from where we parked making the hours spent wandering really dumb.
gambiting
yesterday at 6:59 PM
That's incredible.
fragmede
yesterday at 8:12 PM
> The terror setting in deeper when the consumer GPS unit stopped responding after 30,000' altitude
Ah yes, the CoCom export control limits so you can't use it to build an ICBM. Legally they're supposed to stop working above 60,000 ft and 1,200 mph, but some manufacturers interpret that as an "or". The rumor was that some really cheap chips out of China failed to implement either, so if you'd bought a crappier gps module, you might have been fine!
That's an awesome story tho!
wolvoleo
yesterday at 10:29 PM
Ummmm.
Any country with the knowhow to make an ICBM can source or build a gps receive without said restriction. Just saying.
That's like putting a sign "no burglary permitted" and leaving the door wide open.
I've recently seen a very concrete example of a Chinese CRPA GPS/Glonass/Galileo receiver which is being integrated into some Russian UAVs. It's a COTS thing the vendor in China will sell to anyone. In addition to not obeying any arbitrary limits on GPS speed/altitude it's a 4-element small array for better signal discrimination.
tonyarkles
today at 2:39 AM
You’ve just described a significant amount of ITAR. Am Canadian but have to deal with it occasionally. MWIR/LWIR imagers are another prime example. I can order way better (spec-wise at least) IR sensors from AliExpress than I can from the US. Something about high frame rate IR being useful for some kind of guidance towards hot things shrug
toast0
yesterday at 11:47 PM
Just cause the rule is dumb doesn't mean it can be ignored...