
Balloon Experiments with Amateur Radio - peter_d_sherman
https://en.wikipedia.org/wiki/Balloon_Experiments_with_Amateur_Radio
======
tagami
We launch about 8-12 HABs a year with K-12 schools across the US. We follow
FAA guidelines, and file a Notice to Airmen (NOTAM) as well as contact local
officials in the estimated landing zone.
[https://www.law.cornell.edu/cfr/text/14/part-101/subpart-D](https://www.law.cornell.edu/cfr/text/14/part-101/subpart-D)

Most of our payloads are under 2.5kg so we can fly on smaller 1000g balloons.
There is a shortage of helium currently, but we prefer it over hydrogen
because it is an inert gas.

If you like to volunteer your time, the US Dept of Education will be making an
announcement in the next few weeks for a CubeSat Challenge. First stage is
building prototypes - which of course could be launched in a HAB or High Power
Rocket.

You can track a number of our flights on [https://aprs.fi](https://aprs.fi)
KK6UUQ. Here is a launch from Saturday that we did with USC and LA Unified
School District:
[https://aprs.fi/#!mt=roadmap&z=11&call=a%2FKK6UUQ-11&timeran...](https://aprs.fi/#!mt=roadmap&z=11&call=a%2FKK6UUQ-11&timerange=86400&tail=86400)

If you are into this, check out [https://magnitude.io](https://magnitude.io)

~~~
dylan604
>There is a shortage of helium currently, but we prefer it over hydrogen
because it is an inert gas.

When we did our launch, we originally planned on a Hydrogen launch because we
were informed of the Helium shortage. We bought all of our equipment based on
Hydrogen being the gas. This is important for those that do not know as
Hydrogen equipment has specific fittings so that it will not work with any
other gas equipment. This is to prevent accidental/unexpected use of Hydrogen
due to it being so volatile.

When we showed up to pick up the tank of Hydrogen, the employee really
hesitated selling us the tank of gas. He explained that the flames from
Hydrogen gas is colorless, so we could be on fire before we even saw the
flames. The flames only display color when the flames catch other material
begins to burn. He ultimately exchanged all of our Hydrogen equipment for
Helium, and sold us the tank of Helium.

~~~
ngvrnd
Father in law (rest in peace) worked for a while at a hydrogen reduced iron
plant. Basically they were baking iron in ovens filled with H2. They had UV
detectors hooked up to alarms for this reason.

------
mikece
How long do the balloons remain aloft? I wonder how practical a balloon-based
emergency communications relay could work after a natural disaster. While
high-altitude, long-endurance (HALE) drones carrying communications relays
make more sense in some cases, a balloon-based system in a box with it's own
helium bottle could be deployed by easily and quickly when needed... but if
it's only good for 20 minutes then maybe it's not such a good idea.

~~~
mdszy
Ours stayed aloft for about 2-3 hours when I did a launch with my college ham
radio club! I can't remember exactly. It got up to ~60,000ft and then the
balloon burst, quickly falling back down. We didn't have much of a parachute,
so a larger parachute could've slowed the descent greatly. I'm not sure what
the laws are about size of parachute/any required descent rates though.

~~~
mikece
Does it make sense to have dual balloons: one smaller one designed to burst at
a target altitude (eg: 100,000 feet) and the other, more durable balloon,
meant to provide a very slow descent, much slower a parachute? That could
extend endurance aloft to several hours.

~~~
mdszy
That sounds reasonable to me. Again, not sure as to the regulations around
that, if you're allowed to use a balloon that doesn't burst at any point or
anything.

Also, realistic bursting altitude is closer to ~60,000ft for most balloons,
just FYI.

------
mdszy
I did one of these last year with my college ham club! Had a blast. We made a
custom PCB with some sensors on it that was supposed to transmit data via APRS
but it didn't end up working. We think it was because the AVR onboard didn't
have enough processing power to reliably generate the audio without missing
bits or somehow garbling it slightly (there's no error correction in the AX.25
protocol used by APRS). Thankfully we had a redundant transmitter that did
keep it at least sending GPS data, and we had a 360 degree camera on it that
got some REALLY cool footage.

AMA about it!

~~~
Jun8
I’d love to start on this hobby this summer he’ll be 13). I’m not much of a HW
or ham guy. What resources would you recommend to get started on our first
balloon?

~~~
mdszy
You'll want to find out the laws in your area about launching them. In the US,
you can launch them freely without necessarily notifying anyone as long as
they're below a certain weight and meet other requirements (maximum breaking
strength of the line used to attach the balloon to payload, using a radar
reflector, etc.) However, it's still HIGHLY RECOMMENDED that you call and let
any airports know if you're launching close to one.

Look into APRS and how to build (or you can purchase one) an APRS GPS
transmitter, that'll be the most important bit as if that isn't working,
you'll very likely never find your balloon. Once that's working, you can use a
site like aprs.fi to track the balloon in realtime from a laptop/mobile device
and follow it as it flies. Keep in mind it could VERY well travel over a
hundred miles. We launched ours from Decorah, Iowa and we had legitimate
concerns about wind patterns causing it to fly as far as Chicago.

I'd also recommend looking into how to build a "Fox" and how to foxhunt.
That's a big part of these balloon launches too! Once you've gotten as close
as you can with GPS (once the balloon falls below a certain altitude, relays
will stop picking it up on APRS so you'll have only a general idea of where it
fell), you'll want to use a directional (for instance, a Yagi-Uda) antenna and
a handheld radio to try to directionally locate the fallen payload. Funnily
enough for us, we didn't have to foxhunt since it landed in the middle of a
guy's field, when we parked across from his house, he asked what we were up to
- he was friendly and just curious - and we told him, he said he thought he
saw something shiny in his field and assumed it was garbage blown over from
the road or something and let us come over to look at it. Turns out it was our
balloon! The shiny thing was the radar reflector.

Then, put whatever you want in your payload really! We used a paint can
stuffed with foam (it gets REAL cold up there, like -100F, keep that in mind!)
and shoved sensors into it and attached a 360 gopro to the side. You can find
stuff about how to build temperature/humidity/etc data logging setups that log
to an SD card. I'd also recommend that after you retreive your balloon, go to
some place like aprs.fi and download the GPS track data from the launch! Those
sites don't keep it around forever, you'll definitely want a copy for
yourself.

You can get the balloons themselves quite easily, and welding gas suppliers
should be able to get you a cylinder of helium.

Good luck!

------
calebm
For anyone interested in high-altitude ballooning, one of my close friends
sells high-altitude balloon gear here:
[https://www.highaltitudescience.com/](https://www.highaltitudescience.com/).

------
kawfey
I'm beginning to think that a majority of high-altitude balloon experiments
are facilitated by amateur radio APRS transmitters. Balloon launches are also
huge PR events and great for students to get involved into science (and ham
radio!).

You can see almost every balloons with a ham radio payload currently in the
air, in real time at
[https://tracker.habhub.org/](https://tracker.habhub.org/)

~~~
jcims
This is one of those projects that I keep telling myself I’m going to do ‘next
summer’. There’s just enough detail for a successful flight that you really
have to start working on it months in advance, which is why I never seem to be
able to get my balloon off the ground.

One thing I really would like to do is get a stabilized camera and experiment
with some rigging that reduces payload rocking. A steerable parafoil recovery
is also rolling around in the head. All of these ideas exacerbate the
procrastination situation lol.

~~~
dylan604
I've done one of these smaller launches with GoPros up to ~90k. It was a very
fun project including the research on what equipment to use on our budget, the
flight predictions to find a good launch point, to the actual launch and
recovery. I would highly recommend doing it to anyone thinking about it. We
were a group of adults, but it is definitely kid friendly.

I still want to do another launch with improvements learned from the first
launch. All of the improvements definitely require a much larger balloon
(meaning more expensive). I now have friends with HAM license so we can use a
radio for real-time data transmission. I have my Arduino flight computer with
all of the sensors completed. The camera stabilization was the biggest thing I
wanted to solve. Many ideas rolling around in my head as well. Might need a
3rd or 4th flight to finesse, you know, for science!

------
intrepidhero
I did a bunch of research into this last year. High altitude balloons combine
a bunch of super fun science stuff. You've got radio, photography,
space/weather research. Plus when it's all done you go on a treasure hunt in
the wilderness to recover it! Now if only I had bandwidth outside of
work/family.

[https://arhab.org/](https://arhab.org/)

~~~
intrepidhero
And here's the link that started me down the rabbit hole:
[http://leobodnar.com/balloons/](http://leobodnar.com/balloons/)

------
anfractuosity
[https://ukhas.org.uk/](https://ukhas.org.uk/) has some really good
information for people launching balloons in the UK (such as how to track
them, along with the power etc. you can use).

I've only tracked one once, using an old scanner and antenna, but I'd like to
get a decent collinear antenna to use with an SDR.

------
geocrasher
You can learn a lot about the hardware used over at

[http://qrp-labs.com/lightaprs.html](http://qrp-labs.com/lightaprs.html)

Of course he sells stuff to do it, but there are many balloon flights
documented on that site too. Some of them have circumnavigated the Earth more
than once!

