The Planetary Environmental Simulation Chamber PESCha - Development and operation of experimental set-up for thermal vacuum test.

The life cycle of a space mission can be divided into different phases, each related to different aspects of the mission project. The first phases, following the model of the European Space Agency, are focused on the development of functional systems and technical requirements, as well as the identification of the activities and the necessary resources. The intermediate phases focus on project development activities and the qualification of the product and services. The last phases cover the activities carried out during the period of activity of the mission, and its disposal. Phase D is focused on the qualification and validation of the product. It provides confirmation that the project design meets the mission requirements through a verification process. The work of the PEPS laboratory (Planetary environment and Protection solutions) is linked to this phase of the project. Through a thermo-vacuum chamber called PESCha (Planetary Environmental Simulation Chamber) it is possible to simulate the space vacuum and to perform tests in planetary representative environment: these simulations are useful to carry out functional tests on space components and to perform thermal cycles to verify the effect of temperature on the structures. Another important activity is to carry out the forced outgassing of materials, through a procedure called bake-out. The purpose of this thesis is to analyse in detail the operational phases of the PESCha facility and implement potential improvements, in order to speed up the testing activities and qualification processes, and to be able to detail it with more information. This thesis is divided into 4 chapters: •??The first chapter focuses on the characterization of the space environment and its simulation. In the first part, its peculiar characteristics are described, such as the type of radiation present and the effect of orbital debris and vacuum. In the second part of the chapter, the systems to reach the vacuum and the sensors of both pressure and temperature are described in order to monitor the state of the experiments. •??The second chapter describes the PESCha facility, analysing its components, from the largest to the smallest, with a final analysis related to software components. •??The third chapter focuses on the operation of PESCha facility, that is, the vacuum procedures, in order to simulate the thermal and vacuum environment planned during the mission project, and the bakeout procedure, needed to ensure the cleaning of space components. •??The final chapter describes the implementation of a system for thermal feedback control, aimed at improving the thermal performance of the chamber, and of an RGA (residual gas analyser) sensor useful for improving the bakeout process.