This is explained by statistics. Director General of the European Space Agency (ESA) Josef Aschbacher expressed uncertainty about the successful first launch of the Ariane 6 heavy rocket. The first launch of the Ariane 6 heavy rocket is planned by ESA for the period from June 15 to July 31, 2024. Discuss© ESA
According to the head, such uncertainty is explained by statistics: the likelihood of unforeseen problems and technical anomalies during the first launch of heavy launch vehicles is 47%.
Aschbacher also recalled that although the first launches of Ariane 1, Ariane 3 and Ariane 4 were successful, this could not be boasted with the launches of Ariane 2 and Ariane 5.