NEWPORT BEACH, CALIFORNIA--In the international space station (ISS), no one can hear you scream. Or whisper. It's even noisier than it was on Russia's Mir spacecraft, a NASA official reported at the 140th meeting of the Acoustical Society of America held here earlier this month.
NASA has long been aware that certain parts of the station--particularly those built by the Russians--are much noisier than they were supposed to be, thanks to a host of valves, pumps, and fans. Long-term exposure to a spacecraft's racket can lead to permanent hearing damage, as many Mir veterans can attest.
It has become painfully obvious that the newest component, Russia's service module, is no exception. NASA's Jerry Goodman, who's in charge of acoustics for the $100 billion project, reported at the conference that readings taken shortly after the module was attached in July show that noise levels average more than 70 decibels. That would make it as noisy as a machine room or a rattling air conditioner. What's more, Goodman said, "It's 85 [decibels] near the compressor, and 80 near the workstation. ... It's [acoustically] hot."
NASA has managed to get noise levels in the first Russian module, the Functional Cargo Block (FGB), down to "acceptable" levels with the help of sound-absorbent padding, Goodman reported. But the solution is far from optimal. "There's so much hardware trying to quiet the FGB that you could fill this [conference] room with what I call 'Band Aids.' "