Answering Some Pico Balloon Questions

When the US Air Force shot down some suspected Chinese spy balloons a couple of weeks ago, it was widely reported that one of the targets might have been a much more harmless amateur radio craft. The so-called pico balloon K9YO was a helium-inflated Mylar balloon carrying a tiny solar-powered WSPR beacon, and it abruptly disappeared in the same place and time in which the USAF claimed one of their targets. When we covered  the story it garnered a huge number of comments both for and against the balloonists, so perhaps it’s worth returning with the views of a high-altitude-ballooning expert.

[Dave Akerman] has been sending things aloft for a long time now, we think he may have been one of the first to put a Raspberry Pi aloft back in 2012. In his blog post he attempts to answer the frequently asked questions about pico balloons, their legality, whether they should carry a beacon, and what the difference is between these balloons and the latex “weather balloon” type we’re familiar with. It’s worth a read, because not all of us are part of the high-altitude balloon community and thus it’s good to educate oneself.

Meanwhile, you can read our original report here.

29 thoughts on “Answering Some Pico Balloon Questions

  1. FWIW, NASA’s been using Raspberry Pis on balloon payloads for a long while now. Along with a webcam to monitor the LEDs (not kidding). Not sure how long ago they started, but pretty sure it was close to ’12.

      1. If you find out when NASA started flying them let me know as I’d like to follow that up.

        Mine was only a month or so after the first board was delivered, so I’d be surprised if they did it before me!

  2. It’s not so much the direction, but the magnitude. “Left” and “Right” aren’t the issue, is the extremes. One extreme side might be more known for over-alarmism, but the other is known for over-regulation.

    1. In the wider world.. yes, that is true.

      In the US.. the extreme left is 3 people shouting on a street corner in a city with a population of hundreds of thousands. The extreme right on the other hand is an epidemic infecting nearly half the population. Thus my focus on the right.

      1. As a life-long lefty, I beg to differ. The many flavors of cancel culture that have lately become popular are giving us a bad name. It’s getting so bad, I’m beginning to suspect that much of it is false flag operations.

        1. I used to pick on the people on the left pushing cancel culture or otherwise taking it too far.
          Then I saw the right:

          sticking kids in cages,
          adopting out babies they stole from immigrants,
          blaming all their problems on immigrants,
          storming state capitals,
          attempting to institute a race war,
          denying medical science and opposing all attempts to fight a pandemic,
          trying to kidnap a governor,
          trying to subvert elections,
          storming the nation’s capital,
          shooting out power transformers,
          forcing women to give birth to babies with conditions that leave them with zero chance of anything other than days to weeks of suffering before their natural death,
          canceling books in schools

          pretty sure the list goes on but I need to stop somewhere

          So.. the left canceled some celebrities? OMG! What will we do?!?!

        2. Louis C.K. still does shows, Dave Chappelle will probably get more specials, J.K. Rowling is still a billionaire. Practically every person who gets “cancelled” has come out unscathed, unless you’re a big Harvey Weinstein fan or something. It’s awful when somebody normal gets fired for an off-colour comment, but online psychos like to harass people no matter their political stripes (see Libs of TikTok) and that’s more a problem with people being plugged into the internet and feeling impotent in their lives than with a political program.

    1. What might happen?

      It gets shot down?

      I don’t know what it cost them but for a country that had a GDP of 17.73 trillion USD in 2021 do you really think they care?

      Other responses from the US? What are we going to do? Declare war over it? Sanctions?

      Either would cost the US far more than it’s worth.

      It’s an open secret that all nations are spying on all nations. So this one got caught this time, big deal. I’d ignore any specific claims the Chinese make as propaganda but do you really think we aren’t doing the same to them?

      Those are the things to think about if you assume the US didn’t WANT the Chinese looking where the balloon traveled.

      Consider that just a few years ago the US was a member of the Treaty on Open Skys. We were allowing other countries to fly over. Why? The Wikipedia article explains pretty well how it’s good that the nations of the world get the opportunity to see that the others are not preparing to launch a war.

      Beyond that though… ask yourself this.

      What is the first thing that came to mind when you heard there was a spy balloon over the central United States?

      I bet it was NUKES!

      You don’t want them knowing about all those secret missile silos? Wait, if they are secret how do you know about it?

      We might want people to think those launch sites are secret. After all, if we actually intended to use them we wouldn’t want them blown up. But is that what they are for?

      Nukes are not for use. If we use them so will the other side. Then everyone dies, probably world wide. We don’t win that way. Nukes are for MAD, Mutually Assured Destruction. We need to assure the enemy that if they strike us they die too. How do you do that if they don’t even know you have the nukes? You don’t.

      But what if it actually did come to a nuclear WWIII. Wouldn’t we want our nukes to survive so we can at least try to fight back and hope some of us can survive?

      Yes. That’s what nukes on submarines and mobile launchers are for. The stationary ones are targets. Don’t take my word, go look up the term “Nuclear Sponge”. If worst comes to worst and nuclear war does break out we want them to “waste” as many of their weapons as possible on our least populated areas. At least in the short term that will allow the most of us to survive, the rest, like what to eat we will have to figure out in the aftermath. That’s why all those silos are out in “flyover” country. We want them to send their nukes there instead of hitting our populated cities. All apologies to those who live in that region. I guess you can chalk it up to being another reason rural land is cheaper!

      What we have now in all this outrage over the Chinese balloon is politically motivated people using the situation to whip up their followers with no mind to the consequences to national security and of course even less to hobbyists.

      Blown up or allowed to float away, I guess it depends on just what it floated over but either way it should have been handled as quietly as possible. Now it’s been made into a big issue the administration in charge must come out strong against “UFOs” to prevent the other side from using it in the next election. Decisions get made based on politics instead of actual security concerns. That’s where we are now.

    1. But I guess I’m wrong, there. I remember weather balloons from way back, that were huge polyester film balloons. But now I see that radiosondes are light enough that relatively small, biodegradable latex balloons are the current technology.

        1. Weather balloons for radiosondes are usually latex. they only need to go up to 100,000 ft or so, then pop. that only takes 90 minutes or so, no worries about leaking helium in that time frame. Even larger radiosondes that also measure ozone use larger latex balloons.

          1. Indeed. There’s an amateur network that tracks met office weather balloons and I’m not aware of any that don’t pop, so unless I’ve missed some then they’re all latex.

            Helium leaking isn’t an issue for any latex weather balloon as their lifetime is so short. Even deliberate amteur latex floaters tend to pop after 24 hours due to UV degradation.

      1. The twice-daily weather balloons are all latex. Up, pop, down. Telemetry is logged on the way up then the balloon’s job is done. There’s an amateur network to track them down to (near) landing, and some amateurs then go out to collect the free hardware!

    2. All the radiosondes I’ve recovered (RS41-SGP’s launched out of my local NWS office) have been under shreds of latex envelope.

      When I toured the office a few years ago, they were in the process of converting from helium to hydrogen as a lift gas, lots of ESD precautions around the launcher. I’ve heard that more recently they’ve installed an automated launcher so there aren’t even people nearby when they go up.

      Of course by the time they come down, all the lift gas is long gone so it doesn’t really matter. I’m only in it for the sondes (free STM32’s that literally fall from the sky!), but I try to clean up the balloon and tether too if I’m able to recover them.

    3. That is precisely what they’re made of, covered in talcum powder to prevent them sticking to things prior to and during launch.
      latex is presumed to be best for purpose due to its bio degradable nature and also its extremely elastic. Weather balloons can grow to more than 10 times their inflated size at the height of their ascent.

      The Vaisala radiosonde which is attached to them is a mostly polystyrene affair (sadly) which is extremely lightweight but obviously Carries some environmental issues. I believe research into bio plastics and cellulose based shells has been going on for a while… perhaps not with a suitable degree of urgency…

  3. There is only a very tiny chance that what was shot down was that amateur radio balloon. It’s too small and based entirely on speculation. The military has been accustomed to seeing amateur balloons for decades. There’s almost no way it had enough radar cross-section to provoke sending up a fighter jet with an expensive missile. What they shot down was almost certainly something else.
    And whether you like it or not, the cold war never really went away, foreign spying does happen, and we have to pay attention to national interests because China is actually a different actor and will pursue its own interests. It’s not interested in singing Kumbaya with us.
    There is certainly more information about this than is publicly available, and it’s just sheer guesswork and arrogance that leads people here to say “oh they just panicked and shot down my ham radio.”
    The Fox, OAN, stuff is just derangement syndrome on your part.

  4. You’d be surprised how much you can do with latex weather balloons. When you combine them with some altitude control hardware you can float at any altitude from 50 m to 30+ km for 24+ hours. And if you’re willing to combine a couple balloons then 50+ kg payloads are possible.

    Depending on your application there are good reasons to go with plastic balloons, but latex balloons are often overlooked when they’d work just as well for a fraction of the cost.

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