Locating air leaks in manned spacecraft using structure-borne noise

Area of Science:

• Aerospace Engineering
• Materials Science
• Acoustics

Background:

• Manned spacecraft face risks from micrometeorite and debris impacts, potentially causing critical leaks.
• Effective leak detection is essential for crew safety and mission integrity in space exploration.

Purpose of the Study:

• To develop and demonstrate methods for locating spacecraft skin leaks using structure-borne ultrasonic noise.
• To evaluate the efficacy of different sensor and processing approaches for precise leak localization.

Main Methods:

• Utilizing cross-correlations of ultrasonic noise waveforms generated by leaks into vacuum.
• Employing phased-array, distributed sensor, and dual sensor techniques to analyze guided ultrasonic Lamb waves.
• Investigating the propagation patterns of ultrasonic waves within spacecraft skin structures.

Main Results:

• Four distinct methods were developed and tested for leak noise sensing and processing.
• All demonstrated methods successfully located simulated leaks with high precision.
• Leak localization accuracy was achieved within a few millimeters on a 0.6-m2 aluminum plate.

Conclusions:

• Ultrasonic noise analysis offers a viable solution for detecting and locating spacecraft leaks.
• The presented methods, leveraging guided ultrasonic Lamb waves, provide accurate and reliable leak detection.
• Further investigation into the relative merits of each method can optimize future spacecraft monitoring systems.