Story highlights Spacewalk last more than five hours; crews have spent more than 1,171 hours spacewalking

Astronaut Terry Virts found a small amount of water inside his helmet

(CNN) Astronauts on the International Space Station completed a spacewalk Sunday despite the appearance of water inside an astronaut's helmet, NASA reported.

In a tweet, the space agency said astronaut Terry Virts experienced water inside his helmet, just as he did Wednesday, but "it's a known issue; no concern."

The spacewalk lasted five hours and 38 minutes, NASA said.

"Crews have now spent a total of 1,171 hours and 29 minutes conducting space station assembly and maintenance during 187 spacewalks," the agency said in a release.

NASA previously said the suit worn by NASA astronaut Virts has a history of "sublimator water carryover." Water in the sublimator cooling component can condense when the suit is repressurized after a spacewalk, causing a small amount of water to push into the helmet, NASA said.

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