Ariane 1 was the first rocket in the Ariane family of expendable launch systems. It was developed for and operated by the European Space Agency (ESA), which had been formed in 1973, the same year that development of the launcher had commenced. Aérospatiale was designated to lead the programme. Ariane 1 was the first launcher to be developed with the primary purpose of sending commercial satellites into geosynchronous orbit. Crucially, it was designed with the ability of sending a pair of satellites into orbit on a single launcher, thus reducing costs.