Development and integration of a wireless microcontroller for data acquisition in laser interaction experiments for space debris removal

Kurzfassung

In the last 60 years, space travel has become an indispensable tool for mankind. However, due to the numerous rocket launches, many more particles are released into space in addition to satellites, which remain there for decades depending on the orbit altitude. In order to be able to continue space travel in the future, the targeted disposal of space debris plays an essential role. The German Aerospace Center (DLR) Stuttgart has specialized in ground-based disposal using a high-energy laser. Preliminary tests in 2015 demonstrated the generation of thrust by a laser on various materials. To prevent the debris from melting or cracking during disposal, it is necessary to know how much energy is converted as heat in the debris. In order to obtain characteristic values for different space materials about the heat coupling during laser-induced ablation, the experiment from 2015 is modified with a temperature sensor on the back of the sample and performed again in new configuration. The focus of this thesis is on the development of such a sensor, which is applied in the experiment. Various requirements for such a measuring system are listed and serve as a basis for further development. Based on the boundary conditions, a hardware is developed that meets the necessary requirements of a wireless measurement under experimental conditions. Furthermore, the corresponding software is developed, which is responsible for recording and storing the measurement data during the experiment, as well as for the correct program sequence. A further task of the software is to ensure the communication between sensor and user before and after the experiment. From the data of the designed sensor a prototype with a pre-selection of components was then produced manually. This prototype demonstrates the basic functionality and helps to improve the hardware and software, which then results in a final design. A more detailed examination of the mechanical properties follows based on the final model. Since a temperature measurement with a contact thermometer changes the temperature field of the object to be measured and further measurement uncertainties arise from the electrical measurement process, the components of the total measurement uncertainty are explained in detail and quantified with numerical values. Within the scope of the determination of the measurement uncertainty of the overall system, first simulative estimates were also made, which, however, finally lead to the overall uncertainty in an iterative process after the experimental execution. Before performing the experiment, the electronics must be calibrated and after performing the experiment the data must be read out. Therefore, a graphical user interface was developed especially for this purpose, which simplifies the interface between user and sensor by means of the graphical user interface. The applied interface and the developed communication protocol as well as the various functions of the graphical user interface are explained. Finally, various tests are explained, which have to be performed before the experiment is carried out in order to guarantee the full range of functions under operating conditions