3 ms·

Show HN: We chased a weather balloon across Montana and never found it

60 points by radeeyate 1mo ago

Since April, I have been working with Sam Flynn (https://drook.dev https://drook.dev) to make this balloon payload, UpLink. We did a similar launch last year with Hack Club but this was our first independent launch. UpLink was a 491 gram payload testing the insulation properties of 3D printing filaments, while also transmitting 320x240 images over a radio link -- up from the 18x10 images last year! This is a writeup on our engineering process, mistakes made, and learning experiences. It covers: - Custom electronics designed in KiCad - Firmware design - Results from the data we received on the ground - Image transmission - Launch day logistics, and where things went wrong All hardware, software, firmware, and CAD is available on GitHub: https://github.com/radeeyate/UpLink https://github.com/radeeyate/UpLink, licensed + certified as open source hardware: https://certification.oshwa.org/us002826.html https://certification.oshwa.org/us002826.html If you just want to see the images received, I put up a gallery here: https://uplink.gallery.radi8.dev/ https://uplink.gallery.radi8.dev/ If you have any questions, comments, or concerns, let me know. I'm happy to answer anything!

macintux 1mo ago
Impressive level of detail, impressive work for anyone, much less high school students.
ErroneousBosh 1mo ago
The images seem a bit scrambled, presumably due to missing data blocks. At that low a resolution, have you considered maybe Robot36 SSTV?
- radeeyate 1mo ago
  Images are all in order, but some have missing packets. The problem with SSTV is the power required. From some looking it seems that transmitting would need at least 5 watts. This wouldn't be feasible running on the balloon, as it was powered by Energizer Ultimate Lithium batteries.
  - ErroneousBosh 1mo ago
    Oh, yeah FM transmitters can require a fair bit of power. What is it using then, LoRA type stuff?
    - radeeyate 1mo ago
      Yep, the radio link runs LoRa on the 33 cm band (915 MHz)
      - iberator 1mo ago
        you should read about ham radio mate... there are some amazing protocols and modulations to save power. And of course: 7mhz 0.5W transmitter could be heard worldwide... no jokes.
        radeeyate 1mo ago
        I have my license, and I noted about this in the post. I experimented with the U4B for tracking and found it not to be reliable enough. For the future, I'm planning on using the 70 cm ham band for LoRa.
        ErroneousBosh 1mo ago
        It's on a balloon, right? No point pissing about. Go to 4 metres, dangle a J-pole from the bottom. There, now you've just about got Over The Horizon capability.
verelo 1mo ago
Wait, so at 28k/km the temp goes up to 15C? This is all very cool but this temperature reading caught my eye as unexpected.
- radeeyate 1mo ago
  I found that surprising too! This probably isn't a completely accurate number, as the sensor is black and likely experienced some heating from the sun. Something also worth noting is that different layers of the atmosphere experience different temperatures www.noaa.gov/jetstream/atmosphere/layers-of-atmosphere
  - verelo 1mo ago
    Amazing. I love that i didn't know this. When i was studying weather as part of my pilots license i noted the basic mental math that i'd lose ~2 degrees celsius per 1000ft, but never did i take a second to ask, what happens when i go up 28,000 km.
    - newtwentysix 1mo ago
      the article says 28.42 km. where are you seeing 28000 km ?
      - verelo 1mo ago
        yeah i have no idea why my brain decided to type that (twice...), its clearly 28km
happyopossum 1mo ago
Fun writeup! I was surprised by the part about styrofoam boxes though: Despite their popularity, they have a few disadvantages: They come in predefined sizes which mandate a certain weight allowance They cannot be flexible for your specific payload, making it hard to be efficient with payload layout They are expensive compared to more custom solutions This shocks me, as styrofoam is one of the easiest materials in the world to cut, shape, fasten, and customize to your heart's content. I'm all for 3d printing stuff, but in the theater world we build a ton of very detailed (and shockingly durable) stuff out of foam all the time.... Buying a styrofoam box and just accepting that it's gotta be that shape and size feels like a huge waste.
- rtkwe 1mo ago
  Seems like the simple solution is a Styrofoam sheet, a $10 hot knife and some glue solves the customization problem almost trivially.
- nkrisc 1mo ago
  In my intro Industrial Design class long ago we fashioned styrofoam and many other kinds of foam into every shape imaginable with a hot wire, some utility knives, and contact adhesive. A wood rasp worked well for organic and rounded forms (wear a mask), though that’s probably not needed in this application.
- radeeyate 1mo ago
  I think another point I hadn't included was the flexibility I had with prototyping different boxes. The hardware was changing all the time, and being able to just 3d print another revision was very convenient. If I did something like that with styrofoam, it probably would have gotten pretty expensive. The precision you get from printing was also a plus, as there needed to be slots for cameras, antennas, and circuit board mounting holes.
  - TylerE 1mo ago
    What's expensive? You can buy a medium sized cooler for $5 at Walmart. That's a fair bit of foam.
colingauvin 1mo ago
I live in Montana and routinely hunt the Musselshell river valley/Meagher county area. It's maybe my favorite place in the world. So few folks have been there, but spend some time there and you might just find yourself feeling depressed when you leave and not knowing why. Glad to see other folks go through the area. The wind in Judith Gap is insane, so I'm surprised that you never found it. I'll keep an eye out when I'm out there in Sept/Oct.
karim79 1mo ago
Must have been a UAP.
Felger 1mo ago
"which would have otherwise been expensive for the budget of two high school students" High school students !? You are more capable than most of adults from my country, even "of the trade" if I might say.
jmpman 1mo ago
I'd assume hydrogen is a significantly cheaper fill gas than helium. Other than the danger during filling, any other concerns?
- radeeyate 1mo ago
  That was really our main concern. Being our first launch, we didn't want to risk it and wanted to wait until we were more comfortable with the process until taking that step.
pizzafeelsright 1mo ago
Are there groups or clubs to join?

60 points by radeeyate 1mo ago

macintux 1mo ago

Impressive level of detail, impressive work for anyone, much less high school students.

ErroneousBosh 1mo ago

The images seem a bit scrambled, presumably due to missing data blocks. At that low a resolution, have you considered maybe Robot36 SSTV?

radeeyate 1mo ago
Images are all in order, but some have missing packets. The problem with SSTV is the power required. From some looking it seems that transmitting would need at least 5 watts. This wouldn't be feasible running on the balloon, as it was powered by Energizer Ultimate Lithium batteries.
- ErroneousBosh 1mo ago
  Oh, yeah FM transmitters can require a fair bit of power. What is it using then, LoRA type stuff?
  - radeeyate 1mo ago
    Yep, the radio link runs LoRa on the 33 cm band (915 MHz)
    - iberator 1mo ago
      you should read about ham radio mate... there are some amazing protocols and modulations to save power. And of course: 7mhz 0.5W transmitter could be heard worldwide... no jokes.
      - radeeyate 1mo ago
        I have my license, and I noted about this in the post. I experimented with the U4B for tracking and found it not to be reliable enough. For the future, I'm planning on using the 70 cm ham band for LoRa.
        ErroneousBosh 1mo ago
        It's on a balloon, right? No point pissing about. Go to 4 metres, dangle a J-pole from the bottom. There, now you've just about got Over The Horizon capability.

verelo 1mo ago

Wait, so at 28k/km the temp goes up to 15C? This is all very cool but this temperature reading caught my eye as unexpected.

radeeyate 1mo ago
I found that surprising too! This probably isn't a completely accurate number, as the sensor is black and likely experienced some heating from the sun. Something also worth noting is that different layers of the atmosphere experience different temperatures www.noaa.gov/jetstream/atmosphere/layers-of-atmosphere
- verelo 1mo ago
  Amazing. I love that i didn't know this. When i was studying weather as part of my pilots license i noted the basic mental math that i'd lose ~2 degrees celsius per 1000ft, but never did i take a second to ask, what happens when i go up 28,000 km.
  - newtwentysix 1mo ago
    the article says 28.42 km. where are you seeing 28000 km ?
    - verelo 1mo ago
      yeah i have no idea why my brain decided to type that (twice...), its clearly 28km

happyopossum 1mo ago

Fun writeup! I was surprised by the part about styrofoam boxes though: Despite their popularity, they have a few disadvantages: They come in predefined sizes which mandate a certain weight allowance They cannot be flexible for your specific payload, making it hard to be efficient with payload layout They are expensive compared to more custom solutions This shocks me, as styrofoam is one of the easiest materials in the world to cut, shape, fasten, and customize to your heart's content. I'm all for 3d printing stuff, but in the theater world we build a ton of very detailed (and shockingly durable) stuff out of foam all the time.... Buying a styrofoam box and just accepting that it's gotta be that shape and size feels like a huge waste.

rtkwe 1mo ago
Seems like the simple solution is a Styrofoam sheet, a $10 hot knife and some glue solves the customization problem almost trivially.
nkrisc 1mo ago
In my intro Industrial Design class long ago we fashioned styrofoam and many other kinds of foam into every shape imaginable with a hot wire, some utility knives, and contact adhesive. A wood rasp worked well for organic and rounded forms (wear a mask), though that’s probably not needed in this application.
radeeyate 1mo ago
I think another point I hadn't included was the flexibility I had with prototyping different boxes. The hardware was changing all the time, and being able to just 3d print another revision was very convenient. If I did something like that with styrofoam, it probably would have gotten pretty expensive. The precision you get from printing was also a plus, as there needed to be slots for cameras, antennas, and circuit board mounting holes.
- TylerE 1mo ago
  What's expensive? You can buy a medium sized cooler for $5 at Walmart. That's a fair bit of foam.

colingauvin 1mo ago

I live in Montana and routinely hunt the Musselshell river valley/Meagher county area. It's maybe my favorite place in the world. So few folks have been there, but spend some time there and you might just find yourself feeling depressed when you leave and not knowing why. Glad to see other folks go through the area. The wind in Judith Gap is insane, so I'm surprised that you never found it. I'll keep an eye out when I'm out there in Sept/Oct.

karim79 1mo ago

Must have been a UAP.

Felger 1mo ago

"which would have otherwise been expensive for the budget of two high school students" High school students !? You are more capable than most of adults from my country, even "of the trade" if I might say.

jmpman 1mo ago

I'd assume hydrogen is a significantly cheaper fill gas than helium. Other than the danger during filling, any other concerns?

radeeyate 1mo ago
That was really our main concern. Being our first launch, we didn't want to risk it and wanted to wait until we were more comfortable with the process until taking that step.

pizzafeelsright 1mo ago

Are there groups or clubs to join?