Description: Luna will partner with Dr. Daewon Kim and Dr. Sirish Namilae of Embry Riddle Aeronautical University to develop a multifunctional structural health monitoring solution for lightweight composites used in long duration space habitats. A combination of fiber optic sensors, for strain and temperature monitoring, and piezo resistive sensors, for impact detection, will be utilized to provide a flexible and lightweight health monitoring solution. Luna's high definition fiber optic measurement system utilizes low cost optical fiber to report strain or temperature points every 1.25 mm to 5 mm along the sensing fiber. Fiber can be embedded in the composite materials to detect changes in the structure and predict early onset of failure, prior to visible damage. The piezo resistive sensors will be mounted on flexible soft goods materials. During Phase 1, Luna will fabricate a small-scale expandable composite test article and demonstrate the ability to sense strain using embedded optical fiber and detect impact events using surface mounted piezo resistive sensors. During Phase II, Luna will demonstrate a solution that fuses data from both sensing techniques into one platform for a cohesive SHM solution. Phase III will focus on transitioning the technology to NASA and NASA affiliates such as Bigelow Aerospace.

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 in-space 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. 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 to be monitored 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 aircraft 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.