During a Friday (Nov. 6) spacewalk around the International Space Station's exterior, two NASA astronauts encountered a small ammonia leak and sustained very minor glove damage.
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The ammonia, which is used as a space station coolant, can be highly toxic if flakes of the substance are accidentally carried into the space station. Fortunately, tried and tested decontamination procedures worked like a charm and the spacewalkers, nor the rest of the crew, were in any danger. The same procedure will be used today before the astronauts return to the interior.
NASA astronauts Kjell Lindgren and Scott Kelly were 2 hours into a planned 6.5 hour spacewalk to carry out maintenance work on the station's coolant system. Three years ago, the space station crew were faced with carrying out an emergency spacewalk to stop an ammonia leak. An immediate jury-rigging solution was put in place, and eventually new pump was installed. However, the jury rigging had remained in place to this day, so one of Friday's spacewalking tasks was to remove the quick leak fix.
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While opening and closing valves during today's work to top off the ammonia supply, Kelly and Lindgren reported seeing icy ammonia flakes float away from the site. In previous ammonia encounters, spacewalkers were simply ordered to wait outside of the station until the sun had time to sublimate any trace of ammonia from their spacesuits. After mission control was satisfied enough time had passed and any contamination vented to space, they were allowed to return.
In addition to the ammonia leak, Kelly reported minor damage to one of his gloves - stitching had apparently come loose and he reported seeing a loop of thread poking from the material. After assessment, mission control deemed the damage minor and was of no threat to Kelly or the spacewalk.
Other maintenance work involved applying lubrication of the space station's robotic arm among other "mundane" tasks, according to the Associated Press. At time of writing, the spacewalk was ongoing.
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Kelly has just marked his 224th day in Earth orbit, a record for NASA astronauts. He arrived at the space station last March and he is due to leave in March 2016, completing a whole year in space. Russian cosmonaut Mikhail Kornienko is also participating in the year-long experiment into long-duration spaceflight effects on the human body.