The decision about the setting up of the Pleiades program is the result of an in-depth study about the user needs evolution. A cooperation program was initiated between France and Italy, taking advantage of all the CNES Earth observation skills, to develop ORFEO, a dual Earth observation system with metric resolution, in which Pleiades (France) is the optic component and Cosmo-Skymed (Italy) is the radar component.

This component is made of two "small satellites" (mass of one ton) offering a spatial resolution at nadir of 0.7 m and a field of view of 20 km. Their great agility enables a daily access all over the world, which is a critical need for defence and civil security applications, and a coverage capacity necessary for the cartography kind of applications at scales better than those accessible to SPOT family satellites. Moreover, PLEIADES have stereoscopic acquisition capacity to meet the fine cartography needs, notably in urban regions, and to bring complete information given by aerial photography.

With respect to the constraints of the franco-italian agreement, cooperations have been set up for the PLEIADES optical component with Sweden, Belgium, Spain and Austria.