Instrument software development for Langmuir probe onboard ROMEO satellite

Sammanfattning

The Langmuir Probe is an instrument used to measure the physical properties of plasma. A payload consisting of two Langmuir Probes is in development by the KTH Royal Institute of Technology Division of Space and Plasma Physics. The payload is part of The Research and Observation in Medium Earth Orbit (ROMEO) space satellite mission organized by the University of Stuttgart Institute of Space Systems. To conduct medium earth orbit plasma characterization experiments payload software for controlling the bias voltage applied to the Langmuir Probes is necessary. The development of software consisting of constant and sweep bias measurement modes is described in this thesis. The payload system consists of two main components. The microcontroller will handle communication with the on-board computer. The field programmable gate array will obtain data from analog to digital converters connected to the Langmuir probes, apply filtering and decimation based on measurement parameters, and forward the data to the microcontroller. The implementation of communication protocols Space Packet Protocol and Packet Utilization Standard and the measurement parameter handling are the main tasks of this thesis. Implementation was done from institutional heritage. Reuse of mi- crocontroller code was minimal due to unique mission requirements, field programmable gate array code was updated to handle dynamic parameters for constant and sweep bias modes of Langmuir Probe current measurement. Due to time constraints, the software was partially implemented and tested for correctness. The implementation includes a Space Packet Protocol library, Packet Utilization Standard services, and constant and sweep bias measurement mode parameter handling, saving, and reading. Future work includes finishing the implementation to fulfill the software requirements and conduct full end-to-end verifcation of the payload.