Development and manufacturing of high performance ribbons structures for the inflatable habitat module technology

The inflatable technology for space habitat modules is one of the most promising and beneficial technology in the field of human spaceflight. In fact inflatable deployable habitats will guarantee considerable volume and mass savings (in the order of more than 50%) at launch compared to the current applied metal-based solutions. The technology is based on several flexible layers composing the module structure able to provide one or more specific functions. The Structural Restraint, a seamed mesh of high performance ribbons, is the layer designated to sustain the loads generated from the difference between the module internal operative pressure and the external vacuum. Within the STEPS2 project the consortium developed and manufactured a small representative segment of the Restraint (breadboard) to perform a biaxial tensile test and successively a cylindrical ground prototype for the system functional tests (folding and packing, deployment, inflation). The Restraint breadboard is composed of 4 longitudinal ribbons, 4 circumferential ribbons and all the 3 different properly qualified connection seams. The manufacturing process was previously studied and defined as well as the used tools. Specifically in order to determine the seaming sequence several trials were implemented on a dummy restraint made of PES ribbons with the same dimensions & configuration as the original one. In terms of tools two dedicated metal seaming masks were designed and manufactured. The process was preliminary implemented on the breadboard and then on the final cylindrical ground prototype. The paper reports all the development and manufacturing steps and shows the obtained HW results including the biaxial tensile test outcomes.