High-Altitude Adventure with a DIY Pico Balloon
spectrum.ieee.org49 points by jnord 4 days ago
49 points by jnord 4 days ago
The cost breakdown here is wild - like $20 for something that can circumnavigate the globe? I remember when doing any kind of "near space" stuff required weather ballons that cost hundreds of dollars and you'd lose all your gear when it came down.
The WSPR tracking part is really clever too. Instead of needing your own ground stations or paying for satellite time, you just piggyback on the existing ham radio infrastructure thats already listening 24/7. The whole thing feels like peak hacker ethos - using existing systems in unintended ways.
Kinda want to try this now tbh. Anyone know if theres legal issues with launching these? I assume the altitude means you dont need FAA clearance like regular drones but not totally sure.
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.
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
If you're interested in high altitude ballooning, there's an active community around it.
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.
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.
lol. WPRS works like 10.000km per WATT on HF. You can't do it with 2.4ghz.
Ham radio basics
Why do they do WSPR on HF and not 2.4GHz?
What's the important part that defines what kind of range you can get?
lol. 10.000km with a few bits of fixed-structure payload you mean.
Encoding basics
QRPLabs sell even lighter trackers https://www.qrp-labs.com/u4b.html
and AFAIK are the goto supplier for HAB (High Altitude Ballooning) enthusiasts.
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).
If you are wanting to send images, there are already some cool ways to do that: either SSTV (https://en.wikipedia.org/wiki/Slow-scan_television) or Wenet, which sends them at a much higher speed: https://github.com/projecthorus/wenet.
I wrote some code to send SSTV because everything was either proprietary and didn't work, shareware and didn't work (and often with the original author gone Silent Key so no way to get the real version), or under some vaguely-specified licence and written with Tk widgets in Fortran or some damn thing.
I wrote it about 25 years ago and can't currently find it but it's one one of these hard disks in these here blue moving crates somewhere. It'd take less time to recreate than find, I suspect, especially if I also wanted to make it build nicely in gcc from this decade.
It just grabbed from a V4L2 source, and emitted a burst of Robot36 over the soundcard. In conjunction with a heavy-duty Tait T2000-family transceiver I used it to livestream a drive across Glasgow, slowly and noisily, sending one picture per minute which gave the poor PA transistor time to cool a bit ;-)
Very cool! Brings this to mind: https://www.theguardian.com/us-news/2023/feb/17/object-us-mi...