Around 7 a.m. EST a smoke and fire alarm was generated by the Japanese Kibo laboratory, part of the International Space Station complex. A rapid investigation proved the alarm was false, the third false station alarm during the STS-129 mission. The two previous alarms originated in the new Russian Poisk mini research module.
Transfer operations underway aboard the complex might have stirred up dust particles that triggered the sensitive station alarm sensors. Operations are returning to normal.