NASA has prematurely terminated the extra-vehicular excursion (EVA) – or spacewalk – that Astronauts Tim Peake, KG5BVI, and Tim Kopra, KE5UDN, had been undertaking since early this morning. The two had been carrying out maintenance work to replace a voltage regulator near the solar arrays that failed in November outside the International Space Station (ISS) when Kopra reported what NASA Control called “a small amount of water” inside his space helmet. NASA cut the spacewalk short at about 1700 UTC. The maintenance work already had been completed, and the pair was carrying out other tasks that required crew members to be outside the ISS, when NASA Control, invoking its conservative flight rules, called Peake and Kopra back inside.

The incident recalls the 2013 problem suffered by Luca Parmitano, KF5KDP, when his helmet inexplicably began filling with water, developing into an urgent situation by the time Parmitano and fellow spacewalker Chris Cassidy, KF5KDR, had been undertaking at the time. NASA subsequently blamed the buildup of water on unexplained cooling system issues. NASA has indicated this seems to be the case today as well.

The January 15 spacewalk was the first for Peake, and the third for Kopra. Peake, the first UK astronaut, and Kopra arrived at the ISS in December. 

All Amateur Radio equipment on the ISS is routinely shut down during EVAs, effectively postponing planned commemorative ARISS slow-scan TV transmissions.