Heads down, do the work

Early prototypes were back-of-the-envelope designs, but several technologies and some serious development were required to make the HAPP a reality, as some of the engineering trade-offs were pretty tricky. Building a system is easy. Building a reliable one that can be lifted 30 kilometers by a hobbyist's weather balloon is not.

Check out some highlights below or visit the blog to see how the sausage is made.


ELECTRONICS and cameras

The HAPP runs on custom-fabricated, open-source hardware centered around two Arduino Mega 2560s. Learn about the multiple power busses, sensors, and communication devices crammed onto the Electronics Deck of the HAPP, as well as the various onboard cameras.

CARBON FIBER structure and aeroshell

Unexpectedly, this was the most time-consuming part of the HAPP project. After exploring alternative materials, we settled on carbon fiber. Unfortunately that meant learning how to make a large aeroshell. In a basement. With parts from the local hardware store. But somehow we stayed true to the DIY ethos...

cold gas reaction control system

This is one of the systems that distinguishes the HAPP from all other high altitude balloon projects. From optimized jet nozzles to high-speed valves, read about the engineering behind the most complex part of the vehicle. Achieving light weight, small packaging, and good performance was not trivial.

earth landing system (parachutes)

Kaboom! Few things are more satisfying than watching three huge parachutes explode out of carbon fiber mortars. One of those things is watching the HAPP land safely. Learn about the highly engineered system that makes it happen.

balloon, tether, and cutdown

There's more to flying the HAPP than simply tying a string onto a balloon. The entire system must withstand howling winds in the jet stream and the shock of parachute inflation while keeping the weight low. Finite Element Modeling, high strength alloys, and plenty of Kevlar string team up to get it done.

software and telemetry

This is the heartbeat of the HAPP. Read about the code we developed to run the onboard computers and the ground-based application stack. Also learn how we relay telemetry to the ground and stream it to Tranquility, the mobile app.


All the hardware and software is useless if we can't get it into the air. From flight planning and FAA requirements to ground operations procedures, explore the human technology needed to execute a HAPP mission.

Read about the development in real time

Visit the blog →