Don’t Shoot!

The recent news of 3 more balloons shot down by US fighter jets has many folks worried about everything from other spying activities to alien invasion.  However, given what I know from the media (which can be unreliable, nevertheless) I have a strong theory about what those 3 balloons most likely were.  And if so, the truth should help you calm down about these incidents, if in fact you were a bit worked up with them.

All 3 balloons fell into a general description that I know as a “radiosonde.”  For many, many years and even now, satellite-based data gathering operations for weather prediction just don’t get the kinds of data you can get from a radiosonde.  In fact, as a youngster in the 60’s,  I often dreamed of one landing near me to recover for “reverse engineering.”  Instead, I bought some off of surplus markets to learn their inner workings!

So what is a radiosonde?  It is a small electronics package designed to receive GPS location information and at the same time measure temperature, barometric pressure and humidity (in the most common scenario). In turn, it relays that information to ground stations via a small transmitter.  Battery operated, they have a finite lifetime in use of a few hours. There are no cameras or video downlinks – just the data mentioned above. Wind speeds are reflected in positional changes. These are launched with balloons filled with helium such that they reach a maximum altitude and burst, leaving the small electronics package to plummet back to earth.

And who exactly sends these out?  There is really quite a mix of folks who do.  And as long as they are following established FAA rules, there is no need involve things such as permits or licenses.  These are typically less than 4 pounds, often much less.  The National Weather Service sends these up every day from different locations around the US.  Universities do, private research firms do and so do Amateur Radio enthusiasts around the world.  Some years ago at the college where I taught the Plastics Department crafted the high altitude balloon and the Electronics Department made a suitable tracking payload.  At least 2 were recovered – one in northern New Jersey.  Most of the others flew out to the Atlantic and were lost in the “soup.”  Every day, dozens of these are released all over the world.

If you don’t conclude from this description that these devices are harmless “robots” directed by the upper atmosphere winds, then I haven’t done my job well enough. I’d encourage you to do some net searches and see what is out there on the radiosonde topic!

Can you see what is up there in real time?  Indeed you can!  I took a snapshot of a reporting page from as I was writing this blog entry on a Sunday afternoon.  Here is what I found:

There is a lot of detail on the map, and I encourage you to go to and get a map of your current area.  The map is interactive, and the legends are well-explained.  So long as the radiosonde is programmed to send its information on certain common reporting frequencies, ground stations (often radio amateurs!) report those received via internet to, and they in turn create a realtime map with location data and other information about the devices aloft.  There is also a special version of the site that only reports amateur radio balloon beacons,

I’d be remiss if I didn’t add some additional detail about those sent up by the Amateur Radio folks (and also, other technology-based clubs out there, more on that later).  Nothing says you can’t have a solar cell array to power your device.  The main limitation is weight (4 pounds), so radiosondes sent in this small category are not going to be physically huge or pose a threat to the ground.  The pico-balloons of radio amateurs are barely over a few ounces. Yet these humble payloads can traverse the entire globe so long as they remain intact.  These might have been the types that China claimed flew over them!  Once released, these small devices are entirely at the whim of the winds. Indeed, after being blown up by an AIM-9X missile, there was nothing to recover!

Launching high-altitude, circumnavigational pico balloons has emerged only within the past decade. They are designed to be neutrally buoyant at around 43,000 feet. An 11-gram tracker on a tether, along with HF and VHF/UHF antennas to update their positions to ham radio receivers around the world. At any given moment, several dozen such balloons are aloft, with some circling the globe several times before they malfunction or fail for other reasons. The launch teams seldom recover their balloons.

Recently NPR published an article on the Alaska balloon, and you can read it here:  This was a balloon created by amateur radio hobbyists for their own learning and research purposes, and was launched under clear FAA rules for such projects.  If you really want to get into the “nuts and bolts” this site has kits ready to go for enthusiasts to purchase!

Other balloons are sent aloft to test spacecraft components and physics experiments:

Yes, a payload that fails or doesn’t report through the standard means could pose some risk.  But if NORAD simply got a spare computer to put up for monitoring, we might save some stress on aircraft and early warning systems.

Methinks a half-million dollar missile to down a $100 harmless balloon seems like an overreaction, if not a waste!