NASA had to cut Tim Peake's first spacewalk short after his American partner Tim Kopra reported a helmet water leak.
The spacewalk was originally scheduled to last for 6 hours. When Kopra informed mission controllers of water in his helmet that measured a few inches, the flight director took the matter seriously and ended the mission early. The two Tims spent a total of 4 hours and 43 minutes out of the ISS.
Kopra was able to sample the water and said it was cold, signifying that it was indeed a leak in the cooling system of the spacesuit.
"When we found water on the visor, that was when we pulled the trigger and terminated the walk," says flight director Royce Renfrew.
Renfrew and his crew immediately instructed the astronauts to end the mission. About 15 minutes later, the space explorers were back inside the Quest airlock. Kopra detected the leak before 17:00 GMT, and the astronauts received the instructions to return at 16:58 GMT.
Although the spacewalk ended earlier than planned, the astronauts were able to perform their mission successfully. Early into the spacewalk, they were able to remove and replace the failed voltage regulator outside the ISS. All it took them was 31 minutes.
Throughout the mission, NASA astronaut and station commander Scott Kelly and Roscosmos' Sergey Volkov and Yuri Malenchenko were there to assist. Once their colleagues were back at the ISS, Kelly collected a 15-millimeter sample of the water and removed the absorption pads from Kopra's helmet.
Kelly said Kopra's shoulders and wrist area were wet. He also found that his colleague's cooling garment beneath the spacesuit was moist.
Peake's wrist area also moistened but overall he was unaffected. When he arrived back at the station, Peake thanked the mission controllers and said they did a great job.
"Today's exhilarating #spacewalk will be etched in my memory forever – quite an incredible feeling!" he said.
The recent incident is not the first helmet water leak experienced by an astronaut on a spacewalk. On July 16, 2013, Italian astronaut Luca Parmitano also had the same encounter but his experience was much worse as the water leak obscured his vision.