Lightweight Inflatable Structural Airlock (LISA), Phase II

Innovative low cost, light-weight airlock technologies are required to integrate with deep space and surface platform hosting Extra-Vehicular Activity. CFDRC team proposes an inflatable airlock structure that employs unique fabric architecture capable of delivering the lowest mass and greatest versatility of any competing design. The proposed design features a completely integrated air beam inter-wall to passively generate the wall stiffness required for airlock depressurization?without the mass and bulk of aluminum pressure hulls or complexity of multi-structure adaptations of competing inflatable habitat architectures. This unique architecture utilizes a matrix of braided fiber tendons to contain the structure?s global pressure loads. The underlying woven fabric and gas barrier envelopes are thereby only exposed to minimal local shell loads where they bulge outwards between adjacent tendons. Working in pure tension in the absence of load coupling, the tendon array architecture has been shown to be statically determinate and auto-stabilizing under extreme deflection. The proposed airlock stows compactly for transport to the habitat further reducing logistic costs. Phase I effort focused on conceptual design of the airlock system, identification and evaluation of candidate materials, and characterization of the airlock system. Phase II effort will focus on design refinement, integrated testing, analysis, and integration plan that will culminate in the fabrication and demonstration of a subscale prototype inflatable airlock structure. More »