Session: 02-03-03: Dynamic Loads, Wave Propagations, Response, Vibration, Control, and Alleviation of Aerospace Structures and Vehicles

Paper Number: 152552

152552 - Langasite Cryogenic Pressure Sensor for Space Shuttle Fuel Tank Monitoring 

With the increasing demand for outer space exploration, particularly for NASA missions, the structural safety of space shuttles has garnered significant attention over the past decades. One critical aspect is the external fuel tank, which stores liquid hydrogen and oxygen at cryogenic temperatures of -253°C and -183°C, respectively. Detecting early-stage changes in temperature or pressure is crucial for preventing serious issues in fuel storage or even catastrophic failures in the spacecraft. Accurate and frequent pressure monitoring within the fuel tanks is essential to avoid malfunctions.

Langasite (Lanthanum Gallium Silicate, LGS), a piezoelectric material known for its high-temperature stability, also exhibits good piezoelectric properties at cryogenic temperatures. However, there has been limited research on the application of LGS in cryogenic conditions. In this study, we designed and fabricated a wireless LGS bulk acoustic wave (BAW) sensor with an "H"-shaped cross-section, along with a housing suitable for cryogenic pressure sensing. A COMSOL simulation was used to validate the resonant frequency of the LGS BAW sensor.

The current housing design is optimized for gas-phase media. The frequency shifts of the LGS BAW sensor were recorded and analyzed using a Vector Network Analyzer, allowing us to relate applied pressure to the frequency changes. This approach enables the determination of internal pressure within an enclosed container. Future work will focus on optimizing the design for pressure sensing in liquid cryogenic media and enhancing wireless transmission range.

Presenting Author: haifeng zhang University of North Texas

Presenting Author Biography: S. Ju pursues his PhD degree in Mechanical Engineering at
University of North Texas (UNT) since he received his Bache-
lor’s degree with same major from UNT at 2018. His research
interests include piezoelectric sensor development, NDE, smart
structures, and piezoelectric devices. He is currently working
on ultrasound-based material property characterization,
piezoelectric semiconductor modeling, and resonance-based
sensor development.