Diapason was a small cylindrical satellite, 20 cm long and 50 cm in diameter which was used for making geodetic measurements.
The Diamant rocket (Diamant is French for "diamond") was the first exclusively French expendable launch system and at the same time the first satellite launcher not built by either the United States or USSR. As such, it has been referred to as being a key predecessor for all subsequent European launcher projects.
Société d'étude et de réalisation d'engins balistiques or SÉREB was a French aviation company. It was created initially to develop two-stage ballistic missiles for nuclear weapons (Force de dissuasion nucléaire française). CNES was formed in 1961, which took over much development of civilian research.WIKI