A Soda Can That Thinks It’s a Satellite

Our Ikarus 3.0 chassis, 3D printed in white PLA. The final flight version will be printed in PETG for better durability.

When we tell people at school that we are building a satellite, we get one of two reactions. Either they assume we are joking, or they picture something massive and expensive being assembled in a clean room by rocket scientists. The truth is somewhere far more accessible and, we would argue, far more interesting. Our satellite fits inside a standard 330ml soda can. We built it ourselves. And it actually works.

This is a CanSat. The name is exactly what it sounds like: a satellite in a can. The concept was developed as an educational challenge to let students experience the full engineering lifecycle of a real space mission, from design and construction all the way through launch, data collection, and recovery. Every year, space agencies across Europe run competitions based on this concept. Teams of students design, build, and launch their own miniaturized satellites, and they have to make every design decision themselves.

330ml MAXIMUM VOLUME, THE SIZE OF A SODA CAN

300g EXACT TARGET WEIGHT INCLUDING PARACHUTE

~1km LAUNCH ALTITUDE FROM A ROCKET

Here is how a CanSat mission actually works. A rocket carries the CanSat up to approximately one kilometer in altitude. At that point the CanSat is ejected from the rocket. A parachute deploys to slow the descent, and during the fall the onboard sensors collect data and transmit it in real time via radio to a ground station operated by the team on the ground. The whole descent takes somewhere around four to five minutes. In that window, the CanSat has to perform its entire mission.

“Every team has to complete a primary mission set by the competition, but they also design their own secondary mission from scratch. That’s where things get creative.”

— Team Icarus 6

Every CanSat team has two missions to fulfill. The primary mission is set by the competition organizers and is the same for everyone: measure temperature and air pressure during descent, and use those measurements to calculate altitude and rate of fall. This sounds simple but requires a well-calibrated sensor, reliable power management, and a radio link that actually works while the satellite is plummeting toward the ground at up to 11 meters per second.

The secondary mission is the part each team designs themselves, and this is where it gets genuinely exciting. We chose to measure CO2 concentration in the atmosphere during the descent. The idea is to see how CO2 levels change at different altitudes, from ground level through the lower atmosphere. We are pairing that with a GPS module so we can track the CanSat’s exact position after landing and recover it more easily.

To run all of this inside a volume the size of a soft drink can, we are fitting in quite a lot of hardware. The brain of the system is a pair of Raspberry Pi Pico microcontrollers. These run MicroPython code that handles everything from sensor readings to radio transmission. The radio transceivers are RFM69HCW modules operating at 433MHz. Our ground station uses a Yagi antenna, built from scratch out of a wooden stick, aluminum bars, coaxial cable, and a whole lot of zip ties.

Inside the can there is also a BMP280 sensor for temperature and pressure, a TMP36 backup temperature sensor, the SCD41 for CO2, the GPS module (a PA1616D), a lithium battery, a voltage converter, and a buzzer that starts beeping after landing so we can find the thing. All of that, crammed into 66mm of diameter and under 115mm of height, and it has to weigh exactly 300 grams when it is all assembled.

Why does any of this matter?

CanSat is not just a school project. It is a compressed version of how real space missions work. Every engineering decision you make interacts with every other decision. The weight of the chassis affects how fast it falls. How fast it falls affects how much time you have to collect data. How much data you collect affects how you design the radio transmission protocol. And if any one of those decisions is wrong, the whole mission fails. Learning to think in systems like this, at 16 or 17 years old, is one of the most valuable things we have ever done.

The competition in Luxembourg is organized by ESERO, the European Space Education Resource Office, in partnership with ESA and the Luxembourg Space Agency. Students from schools across the country compete, and the best teams get the chance to represent Luxembourg at the European CanSat competition. We are hoping to be one of them.

If you are a student wondering whether something like this is for you: it is. You do not need to already know how to code, or how to solder, or how to design in 3D. None of us were experts when we started. What you need is curiosity and the willingness to spend your Friday evenings arguing productively with people who care about the same problem you do. The rest you figure out along the way.