Western scientists met with their "colleagues" from the Soviet bloc. The main politi-cal-diplomatic objective was to show readiness for dialogue, the other obvious one was to find alternative channels of information on Soviet progress. These contacts took place within the framework of Western collaboration, which developed according to the trajectory of American techno-scientific development. A Euro-Atlantic competi-tion / cooperation, however, took shape in the 1960s, with its own characteristics that have reached the present day, without the process of European construction affecting its more strategic areas. In this context, how can historians relate to the Soviet world? And what image can they draw from it? New evidence seems to emerge thanks to the investigation and intersection of various archival sources, drawn from the most indica-tive experience, the French one, from the Franco-Soviet scientific commissions to the Space "cooperation" with the missions of the spationaute Jean-Luc Chrétien in 1982 and 1988, and then the phase of enhanced cooperation during the Vega 1 and 2 mis-sions in the Halley Army. These two missions aimed at having the comet intercepted by the ESA Giotto probe in March 1986.
Keywords: Space exploration, Soviet space program, scientific collaboration, history of technol-ogy, experts, ESA.