The International Space Station called off a spacewalk planned for Thursday afternoon because of a water leak in the helmets of the crewmembers tasked with carrying it out.
One of those crewmembers is Tim Peake, the first British astronauts aboard the ISS and was going to be the first British astronaut to perform a spacewalk. It was his counterpart, NASA astronaut Tim Kopra, who called off the mission two hours early when he noticed water in his helmet, Space.com reported.
"The crew was never in any danger and returned to the airlock in an orderly fashion," NASA said in a blog post. "The astronauts replaced a failed voltage regulator that caused a loss of power to one of the station's eight power channels last November, accomplishing the major objective for this spacewalk."
In July 2013, Italian astronaut Luca Parmitano experienced a much more dire water leak in his helmet during a spacewalk. While his situation was considerably scarier, he made it back to the ISS safely.
Before the ISS decides on what to do about the spacewalk, they will investigate Kopra's suit to determine what caused the water leak.
Michael López-Alegría, a NASA astronaut with the most cumulative spacewalk hours, told BBC News the astronauts were well prepared for the mission.
"One is that translation [moving from one point to another] is quite a bit different without the viscosity of the water," he said. "This is especially true when [Major Peake] will be transporting relatively large masses (like the SSU) relatively long distances. This fact will change his centre of gravity and will affect the results of the inputs he makes with his hands and arms during translation."