peer reviewed ; International collaborations have always been of prime importance for CSL, from the beginning with their first space projects in the sixties: around 20 sounding rockets launched from Kiruna (Sweden, situated in the province of Lapland), our Stellar UV Radiation Experiment aboard TD-1A launched by a Thor-Delta N from Vandenberg Air Force Base on 11 April 1974, the Faint Object Camera for the Hubble Space Telescope (NASA). International collaborations are quite natural in space science as you put together the needed competencies and capacities from different groups, for a common scientific objective. International cooperation in space enables to achieve ambitious science goals in understanding the Universe, while allowing transfer of Technology, impacting on Science Education and on Economy.