Description: Hypersonic vehicles have various commercial and research uses, including faster global travel, space tourism, cargo, and scientific exploration. However, operating at hypersonic speeds poses new engineering challenges, as conventional aircraft equipment is not adequate for such extreme environments. High-temperature sensors are necessary to monitor structural components during flight and gather data for scientific research. The development of structural health monitoring (SHM) systems for hypersonic flight conditions would allow in-flight monitoring for maintenance scheduling and life cycle monitoring using actual flight history. In addition, knowing the effects of the continuous use strain and stresses could even allow for in-flight trajectory modifications to compensate for any alterations in structural components due to fatigue from continuous harsh environment use. Such systems would be vital in the implementation of operational reusable hypersonic aircraft for long-term use. GTL proposes to design a SHM that can monitor strain and temperature using an additive thin film approach. Using these methods, various sensor types such as thermocouples, RTDs, strain gauges, and more can be produced directly on the surface of the structural components under monitoring. This method offers many advantages including flexibility in material selection, oxidation resistance, superior surface adhesion and is produced additively, allowing the placement of sensors to be highly adaptable to different applications. Previous efforts have shown many successes in using thin film deposition of high temperature, oxidation-resistant materials to produce high temperature sensors and cables. The SHM sensor will use the fabrication methods developed by GTL to produce a single sensor array consisting of both a strain gauge element as well as a thermal sensing element. The design of the strain sensor can be easily adapted to accommodate various load types.

Benefits: There are many research applications that deploy hypersonic aircraft. Research including low gravity experiments, harsh environment effects, material testing and much more where hypersonic aircraft is needed. In addition, NASA has many ongoing experiments with hypersonic, transonic, subsonic, supersonic and traditional aircraft. Any of these aircraft would benefit from the ability to monitor strain and temperature of the aircraft using actual flight history for maintenance scheduling and life cycle monitoring. Many commercial applications can benefit using hypersonic technology. There is transport and cargo, commercial air travel, emergency response, space/suborbital tourism and more. The addition of a structural health monitoring system to aid in life cycle monitoring and maintenance scheduling would be vital in producing commercial fleets of hypersonic aircraft. Supersonic, transonic, and traditional aircraft would all also benefit from this technology.