(CNN) -- NASA is extending the mission of the space shuttle Endeavour by a day so astronauts can do more work on the International Space Station, mission managers announced Sunday.
The shuttle is now scheduled to return to Earth on February 21, after a 14-day mission, the space agency said.
The announcement came as two astronauts completed a spacewalk lasting nearly six hours, NASA said in a statement.
Robert Behnken and Nicholas Patrick were performing the second of three scheduled spacewalks for the mission. It was Behnken's fifth time walking in space, and Patrick's second, NASA said.
They finished the five-hour, 54-minute spacewalk at 3:14 a.m. EST.
The shuttle crew is at work on part of the ISS known as the Tranquility node, attaching it to the space station and readying it for people to live and work on it.
The shuttle mission is formally known as STS-130.