Proba 2 is the second satellite in the European Space Agency´s series of low-cost Proba satellites that validates new spacecraft technologies while also carrying scientific instruments. The nominal duration of a mission will be two years. The second satellite was launched on November 2, 2009. Proba 2 contains five scientific instruments. Two of them are designated to measure basic space plasma properties: the Dual segmented Langmuir Probe (DSLP) Proba 2 and the Thermal Plasma Measurement Unit (TPMU); both were developed by the Astronomical Institute and Institute of Atmospheric Physics of the ASCR. and Pavel Trávníček, František Hruška.