An air leak on the station would sound alarms and the astronauts would locate and correct the problem following established procedures, but with only their eyes and ears to go on, zeroing in on the source of a leak could be tricky, the researchers said.
At NASA's Langley Research Center in Hampton, Va., engineers are trying to use technology to help out.
Working on a program dubbed the Ultrasonic Background Noise Test, they are analyzing the high-frequency noise levels generated by hardware and equipment operating aboard the space station, to develop an automated system that would locate air leaks in a space structure's pressure wall, the outside part of the orbiting laboratory that keeps in oxygen.
Currently, identifying the source of a leak requires someone to listen for the signature hiss of escaping air, not an easy or quick task on a noisy space station that has structures covering the wall where a leak might originate.
As part of the Ultrasonic Background Noise Test, astronauts are in the process of installing several distributed impact detection system units on the pressure walls of the space station.
The units record ultrasonic noises; instead of listening for the hiss of air, they detect the high-frequency sounds moving through the metal itself, the researchers said.
"That's where the rubber meets the road," aerospace technologist Eric Madaras said. "[The transducer] would essentially be stuck on the surface and anything that moves the surface up or down would be picked up."
Madaras and his team say they hope to identify and characterize the day-to-day background noises on the orbiting outpost so they will be able to develop a system that can pick out leak-generated noises from the clutter.
"The idea of giving [astronauts] more time, trying to help them out and get that part done so they can get to the leak, and now they have the tools to fix the leak," Madaras said. "That, to me, would be a good deal."