( 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 . NASA said International Space Station managers had `` a high degree of confidence '' in the suit . On the upcoming spacewalk , Virts and Barry Wilmore installed antennas to provide data to visiting vehicles and deploy 400 feet of cable along the edge of the station . Virts said he first noticed traces of fluid and dampness in his helmet Wednesday while he was waiting for the crew lock cabin to repressurize . He and Wilmore had been outside the space station for nearly seven hours working on the station 's robotic arm and performing some maintenance . Virts immediately alerted fellow astronaut Samantha Cristoforetti about the water , and she alerted Mission Control in Houston . Cristoforetti helped Virts out of his helmet and examined it . She confirmed the presence of moisture , mostly in the helmet absorption pad , or HAP , describing it as `` wet and cold . '' At the request of Mission Control , Anton Shkaplerov used a syringe to draw as much water as he could from the top of the helmet . Water had collected in the white plastic at the top and around both ear cups . Shkaplerov estimated there was 15 milliliters of water in the helmet . That 's a far cry from the amount of water that accumulated in Luca Parmitano 's suit during a spacewalk in July 2013 . Between 1 and 1.5 liters of water backed up in the suit and helmet , prompting fears Parmitano could drown in his own helmet . The spacewalk was cut short , and NASA implemented some changes to its suits , including the addition of absorbent padding in helmets . There was another intrusion of water into the helmet during another spacewalk on December 24 , 2013 . NASA commentator Rob Navias said it was noticed at the same point in the mission as Wednesday 's leak -- during the repressurization of the crew lock , the area from which astronauts enter and exit ISS while in space .
Spacewalk last more than five hours ; crews have spent more than 1,171 hours spacewalking . Terry Virts found a small amount of water inside his helmet .