There are few fears worse than having to confront a fire incident inside a pressurized space vehicle in microgravity orbiting 230 miles above Earth, so there's little doubt that when the International Space Station crew reported smelling smoke late on Tuesday, concern would have been high.
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But fortunately, through the professional response of the astronauts and cosmonauts in space and the rapid response of mission controllers on the ground, the source of the smoke was quickly identified before there was any threat to the six-man crew.
"In line with standard protocol, flight controllers at mission control in Houston followed emergency procedures to isolate the Russian segment ventilation system," NASA said in a statement. "Expedition 40 commander Steve Swanson reported that the smoke quickly subsided and the crew was not in any danger."
The source of the smoke was the Water Dispensing and Heating Unit, which is used for water reclamation purposes and is located in the Russian Zvezda service module. The unit was powered down, removed and replaced with a spare. As reported by the Associated Press, there was a similar problem in 2009.
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Emergency procedures were put in place and any remaining smoke contamination was quickly removed by Zvezda's air scrubbers.
After removal, the crew inspected the faulty unit but didn't find anything "off nominal," so investigations will be ongoing as to why the unit started producing smoke.
With this smokey hiccup behind them, operations on board the ISS continue as normal. The crew are even looking forward to cheering on their teams during down time as the soccer World Cup kicks off today in Brazil. NASA astronauts Swanson and Reid Wiseman, and German astronaut Alexander Gerst will also have the chance to watch their two nations compete against one another during the Group G match between the USA and Germany on June 26 - a match that will be streamed live into orbit and no doubt will spark some friendly rivalry.
Sources: NASA, Spaceflight Now, AP