Party Balloon Crosses Atlantic, Tours Europe & Phones Home

For the past few months, [David VE3KCL] has been launching balloons from his Canadian home fitted with radio transmitters. Nothing unusual there: quite a few people do this, including schools, hackerspaces, and individuals. What is remarkable is how far he has gotten. His S-4 flight in August of this year crossed the Atlantic, reached France and took a tour of Germany, Denmark, Sweden, Finland and Norway before finally landing in the Norwegian Sea. That’s over 10,000 kilometers (6200 miles): not bad for a couple of party balloons strung together.

The flight payload of one of the balloon flights.
The flight payload of one of the balloon flights.

Although the distance these balloons have travelled is quite remarkable, the interesting part is how [David] is tracking the balloons. Cell phones obviously won’t work over the Atlantic, and satellite transmitters are expensive, so he used a low-cost transmitter that was programmed to broadcast using a variety of Ham radio signals. The most effective seems to be WSPRnet (the Weak Signal Propagation Network), a system used by Hams to see how far low strength signals will go. This system relies on Hams leaving their receivers on and running software that uploads the received signals to a central server.

By cleverly encoding information such as height and position into this signal, he was able to turn this worldwide network into a tracking network that would report the balloon’s position pretty much anywhere on the globe. [David] is continuing to launch balloons: his latest went up on the 24th of September and travelled over 4300km (2600 miles) before the signal was lost over the Atlantic.

A Low-Cost Modular High Altitude Balloon Tracker with Mesh Networked Sensors

[Ethan] just tipped us about a project he and a few colleagues worked on last year for their senior design project. It’s a low-cost open hardware/software high altitude balloon tracker with sensors that form a mesh network with a master node. The latter (shown above) includes an ATmega644, an onboard GPS module (NEO-6M), a micro SD card slot, a 300mW APRS (144.39MHz) transmitter and finally headers to plug an XBee radio. This platform is therefore in charge of getting wireless data from the slave platforms, storing it in the uSD card while transmitting the balloon position via APRS along with other data. It’s interesting to note that to keep the design low-cost, they chose a relatively cheap analog radio module ($~40) and hacked together AFSK modulation of their output signal with hardware PWM outputs and a sine-wave lookup table.

The slave nodes are composed of ‘slave motherboards’ on which can be plugged several daughter-boards: geiger counters, atmospheric sensors, camera control/accelerometer boards. If you want to build your own system, be sure to check out this page which includes all the necessary instructions and resources.