Abstract: A breakable joint system for enabling parts to be separated, in particular the top structures of a space vehicle, the system being of the type comprising two plates which mechanically interconnect said parts and which have an explosive charge disposed therebetween, e.g. an explosive fuse cord. The two plates are juxtaposed against each other in a join plane, defining between them a housing for receiving said explosive charge. The end faces of said parts have recesses in which the respective corresponding ends of said juxtaposed plates engage. Fixing means fix the ends of said plates in the recesses of said parts.