Description: The Super-lightweight Aerospace Composites project will advance the maturation of carbon nanotube (CNT) reinforced composites to enable their application in aerospace structures. State of the art lightweight structures are constructed from aluminum, titanium, or carbon fiber reinforced polymer composites (CFRP), with the latter providing a strength to mass advantage over the former. The long-term goal of this project is to contribute to significant mass savings in space structures including but not limited to CNT composite components suitable for Nuclear Thermal Propulsion (NTP) and Lunar/Mars space vehicle structural elements such as pressure vessels, heat exchanger elements and trusses. Attainment of the greatest payoff in structural CNT composites will require the maturation of CNT manufacturing to yield commercial scale volumes and quality of CNT reinforcement not available at the inception of SAC, as well as developing optimal materials processing approaches to capitalize on the performance enhancements promised by this emerging reinforcement material. Evidence of maturation includes building of a mechanical property dataset beyond axial tensile properties typically reported in the literature. Thus far, transverse tensile, axial and transverse flexure, and fracture toughness properties have been generated, with compressive property generation underway. This advancement is made possible with the availability of required CNT yarn being produced at commercial scale in collaboration with a CNT manufacturer. Manufacturing capability has progressed to pilot scale production. This project is conducting modeling and experimental research complementary to the modeling and processing work being carried out under the UltraStrong Composites by Design (US-COMP) NASA Space Technology Research Institute (STRI).

Benefits: Preliminary analysis indicates that there is potential for ~25% mass savings if structural CNT composites can have specific tensile properties at least double those possible with CFRPs. When benchmarked against aluminum, mass savings can potentially be on the order of ~50%. Recent advances in systems analysis indicate that additional quantifiable benefits can be gained by enhancing stiffness of CNT composites relative to SoA composites that can be used not only for primary structures but also secondary structures. The availability of large quantities of high performance CNT material produced in an industrial environment has made it possible not only to generate necessary mechanical properties, but it also enables the evaluation of multifunctional CNT in applications that take advantage of its multifunctional properties in applications of interest to other government agencies. Internally, CNT composite processing optimization efforts are informing potential applications where CNT materials outperform state of the art materials being used.