Wireless Impact and Leak Detection and Location Systems for the ISS and Shuttle Wing Leading Edge

A wireless data acquisition, processing, and communications system for continuous monitoring of critical aerospace structures for potentially damaging impacts and resulting air leaks to vacuum has been developed. The system was initially developed under a NASA SBIR Phase II program to monitor the International Space Station (ISS) for atmospheric leaks due to micrometeor or orbital debris (MMOD) impacts. The system acquires data from multiple ultrasonic transducers and determines approximate leak location through a triangularization routine based on angle of arrival. Subsequently, the system was modified to monitor the shuttle wing leading edge RCC panels during ascent and on-orbit phases for potentially damaging impacts from foam, ice, ablator, and MMOD objects. The wing leading edge impact monitoring system is being installed within the shuttle wings for the return to flight mission, STS-114, and subsequent missions to assist in detecting, locating, and characterizing the severity of impact events similar to the debris impact that caused the Columbia disaster. Resulting data from this system will be used in conjunction with various video systems to determine likely impact locations requiring further inspections, and potentially repairs, on-orbit. Each battery operated unit interfaces with high-speed accelerometers and temperature sensors, records data internally, performs detection algorithms, and transfers data through Shuttle or ISS systems for analysis by ground personnel. The design of both system architectures are discussed in this paper, including sensor interfaces, hardware design, embedded software leak and impact detection algorithms, system operations, and Shuttle/ISS integration methods