On Thursday we met again in Presence to continue the development of our CanSat. Now that we have completed the programming of the individual sensors, today we started on the software for the SD modules. With these, the collected data is redundantly written to two micro SD cards with 32GB data memory each. The redundant storage ensures that if a failure occurs with one of the modules, we will still be able to get data from the other data carrier after the mission and not go out empty-handed. The data is sorted into five different files per SD card for temperature, air pressure, humidity, acceleration and angular velocity, and given the respective mission time. Since we can read out some data, such as the temperature, several times via different sensor modules, we are currently still considering whether the increased measurement accuracy through several independent measurement series is worth it in view of a higher microcontroller load and possibly lower measurement frequency of the other sensors. However, we can only weigh this up after we have tested the entire system with all sensors and the SD modules.
While one part of the team was busy with the data storage, other team members informed themselves about the composition and detection of so-called VOCs - gaseous substances of organic origin in the air. These are of great relevance for our secondary mission, as we will analyse our gas samples collected during the launch campaign for these using a KIT proton transfer mass spectrometer.
We also made progress with the structure of our probe and were able to construct a first CAD model of the lower part of the envelope. In this open area, the sensors will be located in order to measure directly in the ambient air and not inside our CanSat. Since we have not yet received the necessary components of the pump system for the gas collection bags, possible changes to the arrangement of the sensors must be taken into account.