[HN Gopher] High-Altitude Adventure with a DIY Pico Balloon
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       High-Altitude Adventure with a DIY Pico Balloon
        
       Author : jnord
       Score  : 104 points
       Date   : 2026-02-01 00:14 UTC (3 days ago)
        
 (HTM) web link (spectrum.ieee.org)
 (TXT) w3m dump (spectrum.ieee.org)
        
       | pingou wrote:
       | 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 wrote:
         | 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
        
           | squeefers wrote:
           | shouldnt be cruising in the balloon lane then
        
             | ankit_mishra wrote:
             | Balloon doesn't teleport to the balloon lane though
        
           | HNisCIS wrote:
           | That was a much larger balloon that had sand ballast. The
           | sand was what did the damage
        
         | NoiseBert69 wrote:
         | 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 wrote:
           | Yeah, and pico baloons are extremely tiny, often at 10 grams
           | or less, comprising some very thin plastic, some thin wire
           | and tiny PCBs - this is also how they can fly so high for so
           | long.
           | 
           | Lost of types of hail will be much heavier and harder on
           | impact for example.
        
       | mkarliner wrote:
       | QRPLabs sell even lighter trackers https://www.qrp-
       | labs.com/u4b.html
       | 
       | and AFAIK are the goto supplier for HAB (High Altitude
       | Ballooning) enthusiasts.
        
       | ajxs wrote:
       | Very cool! Brings this to mind: https://www.theguardian.com/us-
       | news/2023/feb/17/object-us-mi...
        
       | bambax wrote:
       | 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).
        
         | radeeyate wrote:
         | 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.
        
           | ErroneousBosh wrote:
           | 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
           | ;-)
        
         | m4rtink wrote:
         | 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.
        
       | SuperMouse wrote:
       | 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.
        
         | iberator wrote:
         | lol. WPRS works like 10.000km per WATT on HF. You can't do it
         | with 2.4ghz.
         | 
         | Ham radio basics
        
           | SuperMouse wrote:
           | lol. 10.000km with a few bits of fixed-structure payload you
           | mean.
           | 
           | Encoding basics
        
           | ErroneousBosh wrote:
           | 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?
        
             | maccam912 wrote:
             | WSPR on HF makes sense down here on the surface of the
             | planet because certain ranges of frequencies (not the same
             | range always, but generally always within HF) can bounce
             | off of upper atmosphere layers and pinball back and forth
             | to get signals to someone or from someone who couldn't be
             | seen line-of-sight because of the curvature of the Earth.
             | For line of sight work, the 2.4GHz in theory would work as
             | well as anything, but another trick WSPR has is that it
             | doesn't allow for arbitrary data to be sent. Sender and
             | receiver encode the limited information in an agreed-upon
             | way and then it takes a long time, like minutes, to send
             | that little bit of data. Very high redundancy.
        
               | ErroneousBosh wrote:
               | You know that and I know that, it was a Socratic question
               | aimed at OP ;-)
               | 
               | In the olden days we did QRSS, FSK Morse with a dot rate
               | in the order of minutes.
        
               | m4rtink wrote:
               | 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. :)
        
         | Neywiny wrote:
         | Why not use the STMs that have the LoRa built in?
        
       | sciurus wrote:
       | If you're interested in high altitude ballooning, there's an
       | active community around it.
       | 
       | https://arhab.org/
       | 
       | https://www.superlaunch.org/
        
       | AtlasGains wrote:
       | 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.
        
       | hasbot wrote:
       | Tracking site: https://amateur.sondehub.org
        
       | superkuh wrote:
       | 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.
        
         | daemonologist wrote:
         | FAA wants you to use hydrogen. >roll safe<
        
           | maples37 wrote:
           | Okay, though, for very small hobbyist payloads, though,
           | wouldn't hydrogen balloons be feasible?
           | 
           | Some quick math tells me that you can lift approximately a
           | kilogram of mass per cubic meter (at sea level, anyway). If
           | your balloon's full weight is a half of a kilogram, you'd
           | only need about a large beach ball filled with hydrogen to
           | lift it. That seems like something that would be attainable
           | for an outdoor DIY electrolysis setup.
        
         | sandworm101 wrote:
         | 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.
        
       | m4rtink wrote:
       | 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) :-)
        
       | buildsjets wrote:
       | 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 wrote:
         | 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 wrote:
         | 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.
        
           | ankit_mishra wrote:
           | FAA explicitly requires birds used in strike tests NOT be
           | frozen, because frozen birds do not realistically simulate
           | real bird strikes.
           | 
           | https://en.wikipedia.org/wiki/Chicken_gun
        
           | buildsjets wrote:
           | 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.
           | ..
        
       | HNisCIS wrote:
       | 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
        
       | NoSalt wrote:
       | > _" My first pico balloon made it only halfway across the
       | Atlantic before going silent."_
       | 
       | As if we needed more junk in the ocean.
        
       | nodesocket wrote:
       | 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
        
       | ge96 wrote:
       | I always like their illustrations that "minimalist?" two-three
       | color orange
        
         | IrishJourno wrote:
         | 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).
        
           | ge96 wrote:
           | I like your Video Fridays, good to see latest in robotics
        
       | airbreather wrote:
       | 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])."
        
         | mlsu wrote:
         | 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.
        
           | snitch182 wrote:
           | No but you might get serverely hearing impaired..
        
         | andrewla wrote:
         | 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.
        
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