Lightweight Conformal Structures

The innovation proposed here is a novel tank-and-aeroshell arrangement that exploits the latest composite manufacturing practices to advance the state-of-the-art beyond what was possible during the NASA/Lockheed Martin X-33/VentureStar program (Ref.nbsp;1). By using advanced stitched-composite design and manufacturing methods, a more efficient airframe design becomes possible that fundamentally addresses the manufacturing flaws, scale-up challenges, and permeability issues that caused the X-33 tank specimen failure. The approach proposed in this SBIR is a highly-integrated, load-bearing, unitized skin-stringer-frame composite propellant tank that would be infused-and-cured in an oven, before being mechanically-joined to a separately processed, discretely-stiffened, carbon-carbon aeroshell that would be capable of meeting the stringent structural weight fractions required for single-stage-to-orbit vehicles. This SBIR Phase I proposal focuses on a few key development activities that would demonstrate the feasibility prospects of a unitized tank concept relative to the weight and permeability parameters that were achieved for the X-33/VentureStar multi-piece composite tank design approach.