Abstract: A docking system for space modules includes a docking device having respective male and female coupling members carried by the two space modules. The coupling members are arranged to allow, after they have been brought into their coupled condition, relative rotation of the two modules about the axis of the docking device. The system further includes a plurality of connecting devices arranged to lock the two space modules in a precise relative position after the male and female members of the docking device have been brought into their coupled condition. Each of the said connecting devices comprises a coupling seat located in one of the two modules and a coupling shank carried by the other module and axially movable between a withdrawn inoperative position and an extended coupling position. This coupling shank has a head which is expandible within the said coupling seat to effect the connection between the two modules.