A coolant leak in a Russian module of the International Space Station — the third in less than a year — left two cosmonauts dodging the liquid contaminant during a spacewalk Wednesday as they tracked its source. It turned out to be a radiator originally launched with the Russian Rassvet module in 2010 and now attached to the country's Nauka laboratory module. Cosmonaut Oleg Kononenko and crewmate Nikolai Chub isolated the radiator, according to Russian space agency Roscosmos, adding that the primary coolant loop was not affected and "the crew and the station are not in any danger."
Per CBS News, Kononenko initially reported "the radiator is clean. I don't see anything ... I do not see any traces of coolant," though he went on to report numerous "black spots" on a radiator panel after coolant lines were adjusted and droplets could be seen leaking.
The third leak incident follows on the heels of the large rupture in December that disabled a Soyuz crew ferry ship, which was thought to be caused by micrometeoroid impact, which is what it sounds like — an extremely small meteoroid. A second leak coolant occurred in February when the Progress supply ship attempted an unsuccessful docking at the ISS. Russian officials have not offered a possible cause for the Progress of Nauka leaks.