On-Orbit Health Monitoring and Repair Assessment of Thermal Protection Systems

This SBIR project delivers On-orbit health MoNItoring and repair assessment of THERMal protection systems (OMNI_THERM). OMNI_THERM features impedance-based structural health monitoring (SHM) and uses miniaturized autonomous sensor/actuators to diagnose damage and verify repair efficacy. Implications of the innovation Thermal protection systems are crucial for crew safety. New techniques of on-orbit monitoring and assessment of thermal protection structures are needed for space exploration. An autonomous impedance-based SHM system is one of the few viable solutions; however, this technique has not been applied to thermal protection systems. Technical objectives OMNI_THERM deploys autonomous, wireless, self-powered sensor/actuators that harvest energy from vibration and thermal gradients. Each sensor/actuator is a complete SHM system and reports independently; this computationally distributed framework minimizes single points-of-failure. We have built a prototype, performed SHM on launch support structures, and demonstrated repair assessment. Research description Phase I demonstrates OMNI_THERM SHM on reinforced carbon-carbon (RCC) and other model structures. Phase II includes miniaturization and expands OMNI_THERM capabilities to additional thermal materials, hybrid structures, and advanced composites. Anticipated results Phase I establishes feasibility by detecting cracks, gouges, and stress-induced defects in RCC and other model structures and verifying repairs. Phase II delivers an OMNI_THERM system tailored to on-orbit SHM and repair assessment.