The Cluster mission has been operated successfully for 14 years. As the first science mission comprising four identical spacecraft, Cluster has faced many challenges during its lifetime. Initially, during the selection process where strong competition with SOHO was almost fatal to one of them, finally both missions were merged into the Solar Terrestrial Science Programme with strong support from NASA. The next challenge came during the manufacturing process where the task to produce four spacecraft in the time usually allocated to one demanded considerable flexibility in the production process. The first launch of Ariane V was not successful, and the rocket exploded 40s after takeoff. The great challenge for the Cluster scientists was to convince ESA, the National Agencies, and the science community that Cluster should be rebuilt identical to the original one. The fast rebuilding phase, in 3 years, and the 2nd launch on two Soyuz rockets, paved the way to numerous ESA launches afterward. Finally in the operational phase, the challenge was to operate four spacecraft with the funding for one, to solve serious anomalies, and to extend the spacecraft lifetime, now seven times its initial duration with some vital elements such as batteries not working at all. After the technical challenges, the key scientific achievements will be presented. The main goal of the Cluster mission is to study in three dimensions small-scale plasma structures in key plasma regions of the Earth’s geospace environment: solar wind and bow shock, magnetopause, polar cusps, magnetotail, plasmasphere, and auroral zone. Science highlights are presented such as ripples on the bow shock, 3D current measurements and Kelvin-Helmholtz waves at the magnetopause, bifurcated current sheet in the magnetotail, and the first measurement of the electron pressure tensor near a site of magnetic reconnection. In addition, Cluster results on understanding the impact of coronal mass ejections (CME) on the Earth’s environment will be shown. Finally, how the mission solved the challenge of distributing huge quantity of data through the Cluster Science Data System (CSDS) and the Cluster Archive will be presented. Those systems were implemented to provide, for the first time for a plasma physics mission, a permanent and public archive of all the high-resolution data from all instruments.