Description: Polymer matrix composites are increasingly replacing traditional metallic materials in NASA launch vehicles due to high strength to weight ratio, manipulative properties, and corrosion resistance. However, the inspection and repair methods for these materials are considerably more complicated. For aerospace platform repairs, a composite laminate patch must be manually fabricated on-site and then bonded to the damaged structure. Prior to the bonding or co-curing, a vacuum debulk process is performed on the lay-up, requiring a separate piece of support equipment. The ideal method would allow for a rapid structural repair to be performed in locations with minimal access without the need for extensive tooling, surface prep, cure times and complicated techniques. In Phase I, engineers at Luna demonstrated a comprehensive system that included facile surface preparation, single-bag out of autoclave processing and Luna’s unique fiber optic measurement capability for monitoring repair state. This Phase II program will focus on optimizing these methods for launch vehicle composite damage that can be performed during ground processing of the launch vehicle without the need for full replacement. It is expected that the technology will meet NASA launch vehicle requirements and demonstrate potential for in-situ repairs to spacecraft on long missions.

Benefits: Luna’s composite repair system will be directly applicable to launch pad damage mitigation activities for current and future launch vehicles. Ground processing operators will be able to identify the damage that will require patching and Luna’s technology will enable rapid surface preparation, patch bonding, vacuum debulking and consolidation without the need for complicated tooling or equipment. This should dramatically reduce time and energy costs while maintaining high probabilities of mission success.

Luna’s technology is applicable to a wide range of composite material systems, manufacturing methods, and applications. The barrier and curative approaches can be adapted to prepreg systems that would have prolonged room temperature storage capability with the ability to be quickly cured, out of autoclave and on-demand. The impact of these systems on the broad composite commercial market could be enormous.