The crew on board the International Space Station heard a strange sound again on Friday; the second time in four months. Alexander Kaleri was speaking with flight controllers when he heard a loud, drumlike sound coming from an instrument panel. Kaleri and Michael Foale searched for the source of the sound last time, but they weren’t able to locate it. A spacewalk outside the station was called short because of a suit malfunction before the astronauts were able to see if there was a problem on the outside of the station. Kaleri and Foale are expected to return to Earth in just a few more weeks.