A planned six-hour spacewalk outside the International Space Station came to a dramatic and abrupt end on Tuesday when water started building up inside the helmet of Italian astronaut Luca Parmitano.

Parmitano and NASA astronaut Chris Cassidy were less than an hour into their spacewalk, their second in a week, when Parmitano reported that his head felt wet.

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“My head is really wet and I have a feeling it’s increasing,” Parmitano reported to ground control teams at the Johnson Space Center in Houston.

The cause of the leak was not immediately known.

After quickly assessing the situation, NASA decided to end the spacewalk and told Parmitano to head back into the station’s airlock. Cassidy packed up equipment as quickly as possible, as the airlock could not be re-pressurized until both were inside.

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“I don’t want to make a mistake and make it worse,” Cassidy radioed to Mission Control.

Once inside the airlock, Cassidy kept a close watch on Parmitano, whose communications system was down.

“He can’t hear,” Cassidy told flight controllers. “He looks miserable, but OK.”

Image: European Space Agency astronaut Luca Parmitano, Expedition 36 flight engineer, attired in his Extravehicular Mobility Unit (EMU) spacesuit, prepares to exit the International Space Station’s Quest airlock to begin a session of extravehicular activity (EVA) on July 9 along with NASA astronaut Chris Cassidy (out of frame). Credit: NASA