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. 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.