High-Altitude Adventure with a DIY Pico Balloon

Yeah, our baloon was recorded by WSPR eeceivers thousands of kilometers away when it crossed the arctic circle for a day - we wpuld have no data if it were dependent on line of sight or even just flying over inhabited territory.

And indeed, the relions take minures to send a couple dozen bits of data. But the modulation is done in such a clever way, that it does not really matter - you know ehere the probe with your callsign was, how high, ground speed, temperature and panel volatage. There is quite agressive heuristics applied (eg. different precision for different altitudes as you don't really expect it to stay low for any ammount of time and survive, position via grid squares with course position still available even if you have incomplete data from a relation) so the few dozen bits are enough. :)

It is all super clever and hats off for those who developed this system. :)

I’ve been working on a hobby project to send a Raspberry Pi into the stratosphere (nothing really novel) but with all custom software. The entire process, hardware, and stack is documented on the GitHub [1]. Essentially all the software and major components are purchased. I’m just waiting for the spring and then start some tests with balloons, helium mixtures, and iron out any regulatory issues. If this interest you or you have any experience would love help or contributions. The launch will happen in Tennessee.

[1] https://github.com/stratopi-org/stratopi

Well first, the linked article was regarding a weather balloon that impacted the windscreen, not the engine, and it did cause an injury to the flight crew. Here are pictures of the bloody, glass-shard filled flight deck. https://www.facebook.com/aviation247/posts/n17327-united-air... So the hazard is real.

Now back to your uninformed comment. I do certification testing of jet engines, and we most certainly DO NOT test jet engines against the ingestion of airborne electronics.

I have personally loaded and fired the five barrel bird gun at General Electric’s Peebles Test operation many times over the years. We use a range of birds and bird simulators, but none of them are ever chickens, and none of them are frozen.

There is not any requirement for zero engine damage. Little sparrows will do no damage. Ducks and geese cause extensive damage every single time. Extensive engine damage is permitted so long that the engine shuts down without causing catastrophic damage to the airframe. The specific damage that must be prevented, per 14 cfr 33.75, is below. Any other damage is acceptable.

(i) Non-containment of high-energy debris;

(ii) Concentration of toxic products in the engine bleed air intended for the cabin sufficient to incapacitate crew or passengers;

(iii) Significant thrust in the opposite direction to that commanded by the pilot;

(iv) Uncontrolled fire;

(v) Failure of the engine mount system leading to inadvertent engine separation;

(vi) Release of the propeller by the engine, if applicable; and

(vii) Complete inability to shut the engine down.

https://www.ecfr.gov/current/title-14/chapter-I/subchapter-C...

Isn't H2 better because better lift and being a molecule of two hydrogen atoms it is not quite as slippery as helium and quite easy to make?

From wikipedia "lifting gas"

"Helium is the second lightest gas (0.1786 g/L, 14% the density of air, at STP). For that reason, it is an attractive gas for lifting as well.

A major advantage is that this gas is noncombustible. But the use of helium has some disadvantages, too:

    The diffusion issue shared with hydrogen (though, as helium's molecular radius, 138 pm, is smaller, it diffuses through more materials than hydrogen[4])."

No but you might get serverely hearing impaired..