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High-Altitude Adventure with a DIY Pico Balloon

123 points| jnord | 1 month ago |spectrum.ieee.org

58 comments

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pingou|27 days ago

Pretty cool, although it's polluting so hopefully it wouldn't become too popular (probably not).

"And because such diminutive payloads don’t pose a danger to aircraft" even though they are small and wouldn't make a plane crash, I can imagine they would cause some damage if they ever enter a jet engine, although that would be unlucky as they would mostly fly higher than aircraft. I also wouldn't like it to fall on my head, but with the solar panels as depicted and the small weight I suppose it could somewhat glide.

voidUpdate|27 days ago

It also reminds me of the recent incident where an object (potentially a weather balloon) struck a plane windscreen and caused significant damage to it, as well as injuring one of the flight crew. I don't know if it would cause the same amount of damage given it's size, but hitting any solid object at cruising speed is sure to leave a mark

NoiseBert69|26 days ago

There are thousands of weather balloon starts every day without any damages to airplanes.

It's not factor as long they are not crossing a specific size/weight - jet engines and windows from airplanes are tested to withstand a direct impact.

m4rtink|26 days ago

It is super cool - we managed to launch one on a pair of Aliexpress wedding baloons filled with helium and it tracked all the way from Europe to South Korea, for about a week.

It even breached the arctic circle and entered the jet stream for a bit (140+ km/h ground speed) :-)

airbreather|26 days ago

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])."

moffkalast|26 days ago

The diffusion is the main advantage of using helium, it takes ~3x longer to leak out, which directly affects flight time.

Hydrogen is actually harder to buy in my experience, helium is sold everywhere for cheap in small canisters for parties, whereas the second requires like, industrial welding suppliers that will want to sell you a large tank for a few thousand or making your own electrolyser and compressor. There's no common use case for it you could piggyback on.

mlsu|26 days ago

and at this scale it seems like the hazards of h2 would be pretty minor. You're not exactly going to have a Hindenburg situation with only a couple dozen liters of H2.

andrewla|26 days ago

It really seems like there is no downside to this, other than the minuscule risk of a low-altitude puncture + spark causing a fire, and even there the exposure is small because the amount of hydrogen gas is so much small.

Not to mention that hydrogen is free for anyone who has water and a power source.

SuperMouse|27 days ago

I'm currently thinkering of building a balloon with a 2.4GHz LoRa transmitter (SX128x) and a low-power STM32U microcontroller.

Why?

- You can repurpose 2.4GHz Wifi gear opening many doors

- You can easily include volunteers dumping data from HF into a IP sink for telemetry. TTGO offers boards with 2.4GHz LoRa.

- Theoretically you still can add a "low rate" 868MHz/433MHz and a "high rate" 2.4GHz for transmitting pictures and other stuff more quickly.

- BOM friendly. As the balloon might get lost you have to plan a bit for costs.

Neywiny|26 days ago

Why not use the STMs that have the LoRa built in?

iberator|27 days ago

lol. WPRS works like 10.000km per WATT on HF. You can't do it with 2.4ghz.

Ham radio basics

superkuh|26 days ago

I wish the regulations around HAB were not so lighter-than-air gas centric. Hot air balloons are much more accessible, especially solar heated hot air balllons. But they have much less lift per volume and so the FAA FAR 101 rules basically say they all have to be treated as the type where you inform the FAA beforehand and then every hour about their position among other things.

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

>any balloon that is moored to the surface of the earth or an object thereon and that has a diameter of more than 6 feet or a gas capacity of more than 115 cubic feet.

And the regulations on tethered balloons end up being even stricter than letting them go.

sandworm101|26 days ago

As well they should be. The tether represents far more of a risk to aviation than the actual baloon. Not only it is much larger a collision risk, it cuts through GA airspace where all the delicate stuff flies.

daemonologist|26 days ago

FAA wants you to use hydrogen. >roll safe<

nodesocket|26 days ago

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

sciurus|26 days ago

Very cool project!

I saw you were looking for help sourcing things like balloons and gas. https://groups.io/g/GPSL/ worried be a great place to go and ask for help with that, if you haven't already.

AtlasGains|27 days ago

This is way cooler than I expected. I had no idea you could do near-space stuff for the price of a dinner, or that ham radio networks like WSPR could track something globally without satellites. Feels like one of those “old tech + clever hacks” projects that shouldn’t work but somehow does. Also kind of wild that a party balloon can end up halfway around the world.

buildsjets|26 days ago

I wonder what your liability would be in the event your balloon were to be struck by a commercial aircraft and cause injury to the flight crew or passengers?

https://komonews.com/news/local/weather-balloon-launched-in-...

HNisCIS|26 days ago

That balloon was several orders is magnitude heavier, pico balloons pose no risk.

Note that there are operators running balloons several orders bigger still, like Aerostar. They're essentially flying mid size satellites

NoiseBert69|26 days ago

Jet engines are tested for this.

They basically can shoot (not only throwing!) entire frozen chicken cadavers into engines with zero damage.

The only way they managed break the entire engine was to place little explosives on the turbine wings. Even that didn't cause a fatal disintegration of the jet engine.

Somewhere on YT there's a super entertaining video from a test facility.

bambax|27 days ago

This sounds so cool!

> I’m a little puzzled about the balloons’ telemetry messages received on the WSPR network, as they have been few and far between.

But wouldn't there be a way to send messages to Starlink satellites instead of WSPR? Is it a problem of power consumption? (It would be great to be able to transmit images, not just GPS pings).

m4rtink|26 days ago

Starlink is totally oit of picobaloon range by orders of magnitude - we are talking hundreds of mW at most.

At the same time it is true the board (rpi pico usually) could totally support a camera or other high bandwidth instruments - it just does not have the bandwidth to send the data over wspr, possibly with the exception of some flags based on local processing.

AFAIK some poeple have built dual APRS & WSPR pico baloons, but you will still get pictures back only over populated areas due to APRS having in general much shorter range than WSPR.

HNisCIS|26 days ago

In the summer you could theoretically station-keep a few of these over a city for a few hours at least with proper wind and lift gas planning. Could be enough to fly a stripped town T1000e or similar meshtastic relay during a natural disaster

ge96|26 days ago

I always like their illustrations that "minimalist?" two-three color orange

IrishJourno|26 days ago

Thank you, I'm glad you agree they are nice! The artist is James Provost, he's done most of the illustrations for Hands On since we switched over from photography a few years ago (I'm the IEEE Spectrum editor responsible for the column).

NoSalt|26 days ago

> "My first pico balloon made it only halfway across the Atlantic before going silent."

As if we needed more junk in the ocean.

electsaudit0q|27 days ago

[deleted]

daemonologist|26 days ago

If you keep the payload under 4 pounds I believe it's theoretically unregulated in the US except section 101.7 - don't create a hazard. I would still try to be approximately in compliance with part 101 though. Not a laywer.