International Space Station Commander Scott Kelly used a compound specific analyzer to sample air in the Russian Pirs docking compartment, where a smoke alarm triggered earlier. Kelly reports readings on the instrument are zero, there is no fire, no smoke and no odor. Mission Control in Moscow and Houston have declared this to be a false alarm. In the past, dust particles have been known to cause similar false alarms and the crew never was in any danger. The flight controllers and crew will continue to investigate the cause of the false alarm.
The instrument Kelly used is called a Compound Specific Combustion Product Analyzer, which looks at potential toxic products of combustion, such as a fire, onboard the spacecraft and analyzes carbon monoxide, hydrogen cyanide, hydrogen chloride, and oxygen particles in the air.