Nasa aborted a space walk outside the International Space Station when an astronaut's helmet began leaking potentially hazardous liquid on his head and face.
The incident occurred as Chris Cassidy and Luca Parmitano performed routine cable and maintenance work on the ISS. The coverage was streamed live to thousands of viewers.
Cassidy, a former Navy Seal, and Parmitano, a former Italian Air Force officer, had been working for less than an hour when support crew heard Parmitano cry out in alarm at the fluid building up inside his helmet.
Parmitano, 36, who became the first Italian to walk in space, initially believed it was sweat.
But anxious crew assured him it was not and he had to be helped back into the space station. Cassidy said he thought the half litre of liquid had leaked from Parmitano's drink bag.
Nasa ordered the men to return to the ship when Parmitano reported water getting in his eyes. By the time he was back inside, the water had entered his nose and mouth, he had trouble hearing the radio, and he could barely speak.
"It's a lot of water," Parmitano told his team back in the station's airlock.
"He looks fine," Cassidy said. "He looks miserable but okay."
The space walk was called off after one hour and 32 minutes. It had been scheduled to last six and a half hours.
It was the swiftest end to a space walk since 2004, when Russian and US astronauts were ordered back inside by mission control in Moscow after just 14 minutes, following problems with their spacesuits.