Composante Spatiale Optique (CSO; English: Optical Space Component) is a French military Earth observation satellite program of third generation.
It is sometimes referred to as the MUltinational Space-based Imaging System for Surveillance, Reconnaissance and Observation (MUSIS program).
Since the launch of Helios 1A in 1995, France has developed a series of military Earth observation programs.
The first one was launched in December 2018, and provide Very High Resolution imagery - like the Helios 2 satellites,[7] so around 35 cm [8] from an 800 km orbit.
[4][14] The program cost is estimated at €1.3 billion,[1] with an additional €300 million for the ground segment and 10 years of operations.