The following diploma thesis deals with the design selection of micro-thruster system for 1.5U-3U-6U cubesats. In this work, they were used three different free Matlab Orbital Decay calculation programs, so as to estimate the total satellite lifetime for a space mission. In the beginning there is an extensive survey of all space missions that are smaller than 10kg. In addition, simulations are made at various heights and dimensions. Moreover there is an extensive survey of all Cubase-compatible propulsion systems and all space missions with a propulsion system. After that, all the used propellers are presented and a comparison is made in order to find the optimum in each category. In conclusion are referred the findings of the research conducted in this thesis.