Comment by firesteelrain 14 hours ago
I have launched raspberry pi based PicoBalloons and had one fly for over a year at 40k ft. They are remarkably resilient.
I have used CubeSats in LEO to make amateur radio contacts. AMSAT is trying to get one to MEO/HEO. New cubesats are being released frequently. Not all RPi based and usually custom PCBs. You can buy desk based CubeSats for STEM
It was connected to an Orbs 32” PicoBalloon
https://balloons.online/orbs-32-clear/
I used 36 awg wire and fishing line. The lower half of the dipole is also 36 awg wire.
No flight clearances are required
If any aircraft were to hit it, then it would be obliterated. This includes Cessna’s as well
As a bugsmasher pilot, I’d be most worried about 40k ft of fishing line wrapping itself around the spinny bits on the front. What’s the tensile strength on that stuff?
Doubt it’d cause an immediate issue, but doesn’t sound very fun to remove.
3-6 newtons or about 0.7-1.3 pounds-force
Also it’s not 40k ft of wire. Altitude is 40k ft
The wire is about 16 ft for one leg of the dipole. That is the taught part. The other just floats in mid air underneath the payload
The community is very small and doubtful the sky will be filled with them
The balloons follow the jetstream from where they are launched. I have seen them fly over the Artic Circle, for example
if you're not familiar, 36AWG wire is thin. very thin. according to [0], it is 0.1270mm. seems to me that it might melt free from friction thin.
[0] https://size-charts.com/topics/house-size-chart/wire-size-ch...
I’m familiar; I thought this was tethered to the ground. But it’s self contained within a few meters at 40k ft - not a problem.
I do suspect if you encountered small gauge fishing line being used as a tether, you’d find at least some of it wrapped tightly around your spinner on the ground. Probably not much friction at play.
14 CFR Part 101, Subpart D – Unmanned Free Balloons excludes PicoBalloons due to their size and form
It’s not required at all. These are so small that they are not covered by like FAA type regulations
https://www.zachtek.com/product-page/wspr-tx-pico-transmitte...
Solar cells are polycrystalline. You can buy them on AliExpress (very brittle - takes practice soldering them)
I didn’t use the Traquito Solar truss. Too hard to solder. I used a foam dinner plate and solar tabbing wire
I concur with building picoballoons. It's much more economical. It's hard to recover from a malfunctioning rocket that carried your precious payload, but a burst Yokohama is just a learning lesson.
I prefer the Clear Orbs 32” these days due to the cost of Yokohamas
> had one fly for over a year at 40k ft
inquiring minds want to know. was this tethered? what kind of clearance did you need and what kind of equipment was necessary for safety purposes?