An on-board system or payload of a satellite is required to tolerate the extreme environmental conditions of the space, and to meet the requirements raised by the platform. Even during the early stages of development, it is essential to verify that the system meets the provided requirements, in order to avoid delaying of the mission due to redesigning in the later stages, and to reduce risk of failure during the flight of the spacecraft. A most important part of the verification procedure is constructing a test environment that can simulate the behaviour of specific systems on the platform, so that the developed system can be operated and tested before the assembling of the satellite.
My thesis work consisted of creating a test device for the LMP plasma diagnostic instrument (Langmuir Probe) of the ESEO satellite (European Student Earth Orbiter) of ESA (European Space Agency). The created device connects to the CAN bus interface of the Langmuir Probe, issues scientific data requests thus simulating the onboard S-band Transmitter (HSTX) which role is the collection, storage and transmission to ground station of payload scientific data. The collected data is forwarded by the HSTX simulator to any PC via standard USB port.
The thesis introduces the ESEO mission and provides a brief review of the operation of the Langmuir probe. After defining the requirements on the HSTX simulator, the thesis deals with the given communication protocol used by the ESEO. Considering these requirements, the block diagram of the system can be defined, and based on the diagram, the schematic can be designed. The aspects that were taken into consideration at the Printed Circuit Board design, as well as the whole constructed device are described in the thesis as well. The main principles of the implemented program, as well as the functioning of the device are presented.