R2Home is ready to bring your payload back to high altitude

With high-altitude hot air ballooning, you are at the mercy of winds, which can move your payload hundreds of miles and drop it off in an inaccessible location. To solve this problem, [Yohan Hadji] created R2Home, a parachute-based autonomous recovery system that can fly a payload to any specified landing site within its glide range.

We first covered R2Home in early 2021 when it was still in its early experimental stages, but the project has matured tremendously since then. It has just completed its longest and highest test flight. Descending autonomously from a drop altitude of 3500m, with an additional radiosonde payload, it landed within 5m of the launch point.

R2Home electronics with its isolated case

R2Home can fly using a variety of steerable wings, even a DIY ram-air parachute, as demonstrated in an earlier version. [Yohan] is currently using a performance wing for RC paragliders.

A lot of effort has gone into developing a reliable parachute deployment system. The main canopy is neatly packed in a custom "Dbag", which is attached to a stabilizer parachute to stabilize the system during free fall and deploy the main canopy to a preset altitude. This is done with a servo-controlled release mechanism, while steering is handled by a pair of modified winch servos intended for RC sailboats.

All electronics are mounted on a stack of circular 3D printed brackets that fit into a tubular housing, bolted together with threaded rods. With the help of a design student, [Yohan] also upgraded the single-tube housing to a lockable, foam-insulated design to help it withstand high-altitude temperatures.

The main flight computer is a Teensy 4.1 plugged into a custom circuit board to connect all navigation, communication and flight systems. The custom Arduino-based autopilot takes inputs from a GPS receiver and steers the system to the desired drop zone, which it steers around until touchdown.

The whole project is extremely well documented, and all design files and code are open source and available on Github.