Description: Luna proposes to continue development of integrated high-definition fiber optic sensors (HD-FOS) and carbon nanotube (CNT)-graphene piezoresistive sensors for inflatable space habitat materials to enable full coverage structural health monitoring (SHM) and impact detection. Inflatable habitats are key to reducing the weight of space structures, enabling future long term missions and planetary habitation. There is a need for monitoring the structural health of these habitats, as many of the methods used on earth are not applicable to the space environment or the materials used. To accomplish this goal, Luna has teamed with Embry-Riddle Aeronautical University (ERAU) who is a leader in the development of CNT sensor technology. Luna is teaming with an established manufacturer to fabricate a sub-scale inflatable structure with integrated SHM sensors which will enable thorough characterization of the approach. During Phase I, the team successfully demonstrated damage detection in an inflatable prototype as well as dynamic impact detection of soft goods layers with the technologies. Phase II will focus on increasing the TRL of the sensing technologies and preparing for transition into future NASA missions. Phase III will focus on commercializing the technology with NASA and NASA affiliates.

Benefits: Lightweight composites can provide not only significant mass and size savings, but also allow for more efficient and complex designs for future space vehicles and habitable structures. Use of new lightweight materials also raises a critical need to assess and monitor their structural performance. Lightweight and minimally invasive fiber optic sensors can be embedded in composites during their manufacturing process and utilized afterwards for structural health monitoring. This applies to flexible inflatable structures as well as rigid cured composite lightweight structures. High Definition Fiber Optic Sensing (HD-FOS) technology will provide NASA with a measurement technique that can report hundreds of strain or temperature measurement points along the fiber optic cable, allowing for a detailed understanding of the composite's structural reliability. Combined with piezo resistive surface sensors for impact detection, this multi-functional solution enables a wider coverage area of the structure and can improve sustainability of future crewed missions to Mars.

A multi-functional structural health monitoring technology would provide an innovative and revolutionary solution for many commercial applications. The aerospace and automotive industries are increasingly shifting towards the use of composites in design of future commercial vehicles in efforts to achieve significant weight savings to lower fuel consumption. This innovation will provide the ability to embed or surface mount lightweight fiber optic and piezoelectric sensors to a variety of composite structures and provide an unrivaled level of detail about the structure's performance for increased safety. The solution could be adapted to a variety of applications, from in-flight monitoring of composite fuselages and wings for aircrafts to in-vehicle monitoring of composite panels and springs in ground vehicles. Embedded sensors can initiate a movement towards the use of "smart materials" that provide information about their structural health and can detect the onset of defects or delamination prior to any visible surface damage.