Smoke was spotted on the International Space Station (ISS), raising concern among space travelers living on the orbiting vehicle.
Fire presents several dangers to astronauts in a number of ways. Not only is there danger from flames and smoke, but flames also consume valuable oxygen. This can, at best, tax scrubbers aboard the vehicle.
Russian cosmonauts were the first to report smelling smoke in their main compartment. Concentrations were not high enough to trigger fire alarms, although a burning smell was present for around half an hour.
"In line with standard protocol, flight controllers at mission control in Houston followed emergency procedures to isolate the Russian segment ventilation system," NASA officials wrote in a mission update.
The source of the smoke was finally traced to a water heater in the galley of the ISS.
Space travelers quickly shut off electricity to the heater, and air purification systems aboard the Zvezda (Star) segment of the station began clearing compartment. The cosmonauts turned on a fan and filter to clear smoke from the compartment. Readings were taking from around the station, to assess any damage the smoke may have caused.
The international team of spacefarers is all reported to be in perfect condition after the incident. The faulty water heater was replaced on 11 June, with a spare unit stored aboard the space outpost. This new heater is said to be operating perfectly since its installation. On examination, the residents of the space station said they did not notice anything unusual about the unit which broke down.
On 10 June, the day smoke was reported, space travelers carried out a full day of science experiments, studying plants and human health. They also prepared for an upcoming spacewalk.
"The Japan Aerospace Exploration Agency's Resist Tubule experiment, which studies the mechanisms for gravity resistance in plants, will help researchers learn more about the evolution of plants and enable efficient plant production both on Earth and in space," NASA officials wrote in the daily ISS mission notes.
Astronauts Reid Wiseman and Alexander Gerst managed the Body Measures experiment. This study records detailed measurements of space traveler's bodies, to determine how the human body responds to extended periods in microgravity.
Commander Steve Swanson harvested six romaine lettuce plants that were grown from seeds aboard the orbiting spacecraft. These were grown in the Veggie facility, a low-cost container complete with lights and viewing window for the temporary space farmers.
Appropriately, Swanson also spent part of the day preparing for work he performed the next day on the Multi-user Droplet Combustion Apparatus Chamber Insert Assembly for the Flame Extinguishment Experiment-2.
A similar problem, resulting in the release of smoke, happened aboard the space station in 2009.