(CNN) -- Astronauts from the space shuttle Endeavour completed their spacewalk outside the international space station early Friday -- the first of three scheduled for their two-week mission.
Bob Behnken and Nicholas Patrick installed the new Italian-built Tranquility node and a seven-windowed cupola onto the Unity node of the international space station, NASA said.
The hatch into the new addition of the station is scheduled to be opened about 9:15 p.m. Friday.
It was Behnken's fourth spacewalk, bringing his total to more 25 hours outside the shuttle and space station. Patrick was a first-time spacewalker.
Video: Endeavour's successful docking
Video: Breaking barriers in space
Three other crew members assisted with the walk from inside the space station.
With the addtion of the node and cupola, the space station is about 90 percent complete, NASA said.
The mission's second spacewalk is scheduled for Saturday night and is slated to last 6½ hours.
