What is our project about ?

CanSat is a competition which requires students to construct a can-sized satellite. The competition is organized by the European Space Agency (ESA), and occurs simultaneously across most member states of the European Union. The mission requirements are simple, each satellite must complete the primary, and secondary mission, while remaining within the strict dimensions.

What is the Primary and Secondary Mission ?

Each can has the same primary mission, to measure temperature and pressure at any given time. We utilize LM35DZ temperature sensor, and BMP280 pressure sensor; together these allow us to calculate the altitude of our can. Our secondary mission is to create a precise 3D map of any given area over which we fly. To accomplish this we utilize advanced GNSS and IMU senors as well as the LSP-LSR-1000 laser.

How does our laser work?

For now, we’ve chosen the LSP-LRS-1000 module, as it’s capable of measuring long distances, most importantly the distance between the CanSat and the ground, with a range of up to 1 km. After thorough research, we concluded this module is the best option due to its 0.1 m resolution and accuracy of ±1 m, ensuring precise distance measurements.

How will we analyze the data gathered?

To determine “ground zero” for the mapped points, we will create a plane by mapping four distinctive points, forming a square on our 3D model to show the general elevation of the surface. We will map these points by walking with the GPS, measuring the height above sea level, and applying the data to our 3D model. Next, we will take the CanSat data and plot it onto this graph, which will be processed by our algorithms. This will show the relative height compared to “ground zero” and make it easier to distinguish holes and hills, as the plane is almost completely flat.

We will receive raw data such as GPS position, pressure, temperature, CanSat orientation, and distance traveled by the laser beam. Using the position and time data, we will estimate the CanSat's movement direction with an uncertainty of just 20 cm. To improve motion precision, we decided to change our parachute so the CanSat moves in a specific direction. This will allow us to create a more accurate position vs. time graph.

With the CanSat's orientation, the time of measurement, and laser data, we can find the points in 3D space. We will then subtract the average ground height from our measurements to showcase terrain features more clearly. Finally, after receiving the exact 3D coordinates, we can analyze the landscape and identify possible rocket landing spots for future missions. Our main goal is to create a 3D model of the surface using these mapped points, which we will input into Python and process with 3D sketching libraries.

How does our communication system work?

The communication system is an extremely crucial part of our CanSat, as it lets us transfer all the data directly from our probe to the ground station, where it can be analyzed and stored safely. Moreover, it becomes very useful during the procedure of CanSat recovery after the mission. Faultless activity of the communication system must be provided to make the whole CanSat campaign successful.

The SX1278 transceiver acts as both the transmitter and the receiver in our communication system, with one attached to the Raspberry Pi model 3B+ connected to the computer at our ground base and the other integrated with the Raspberry Pi Zero 2 W positioned inside our CanSat. There is going to be two-way communication, where data from devices working inside our probe is transferred to the mainboard, saved, encoded into binary format, and transmitted to the ground station using SX1278. Our transceiving will use LoRaWAN, chosen for its small data losses, transmission range, low energy requirements, and bi-directional communication capability.

For successful encryption of files containing the data collected from the sensors, we will use a program written in Python, which offers extremely easy control of the input and output, as well as easy-to-use libraries needed for handling such procedures. After encoding the data into binary language, Frequency-Shift Keying will modulate sinus waves, with stretched periods corresponding to zeros in binary language. Our waves will be transmitted at the 433MHz frequency, which is the frequency allowed for private use in the European Union. The communication system of our CanSat will have the range of transceiving up to 10 kilometers in clear weather conditions.