In January 1965, the French thought the initial three-stage rocket design would not be sufficiently advanced to carry the size of payloads required, while another rocket - referred to as "Eldo B" - which featured liquid hydrogen-fuelled second and third stages, came to be viewed as being a superior design, partly due to reduce the cost of the project via the elimination of transition test launchers. It would still use the Blue Streak as the first stage. The ELDO later disagreed, but the French would ultimately get their way when Eldo B became the foundation for the later Ariane launcher, which would first launch in 1979.