The French CSO (Composante Spatiale Optique) high-resolution reconnaissance satellites are the optical space component of the MUSIS program that will replace the current Hélios 2 military observation satellites. As the prime contractor for the CSO satellites programme, Astrium will provide the agile platform and avionics, and will also be responsible for the integration work, testing, and delivery of the satellites to CNES. Thales Alenia Space will provide Astrium with very high-resolution optical instruments.