Astronauts Bob Behnken and Nicholas Patrick are back on the International Space Station after successfully unloading and installing the 16-ton Tranquility node during a 6.5-hour spacewalk. The newest addition to the ISS was installed at 1:20 a.m. EST over the Indian Ocean west of Singapore.
Once Tranquility was structurally attached to the ISS, the spacewalkers connected heater and data cables that will integrate the new module with the rest of the station's systems. They also pre-positioned insulation blankets and ammonia hoses that will connect Tranquility to the station's cooling radiators during the mission's second Feb. 13.
When the spacewalk ended, Mission Control reported that all data and heater connections were working well, and that the vestibule separating Tranquility and the ISS had passed its initial leak check. Tranquility's hatch is scheduled to be opened at about 9:14 p.m.
The event drawing the most attention during the mission, the cupola that will attach to Tranquility -- the so-called room with a view -- will be moved from Tranquility's end to its Earth-facing port on Feb. 14.
The spacewalk was the first of three scheduled spacewalks on the current mission, the 231st conducted by U.S. astronauts, the fourth for Behnken and the first for Patrick. It was the 138th in support of ISS assembly and maintenance, totaling 861 hours, 34 minutes. It was the 110th spacewalk out of the space station, totaling 674 hours, 19 minutes.
After the node and cupola are added, the orbiting laboratory will be about 90 percent complete.
Tranquility was built for NASA by Thales Alenia Space in Turin, Italy, under contract to the ESA (European Space Agency). Although Tranquility was actually delivered in May, NASA did not officially take possession until Nov. 30.
Spanning about 22 feet in length and 14 feet in diameter. The new component will provide an additional docking point for space shuttles and other crew vehicles visiting the station.
According to NASA, the cupola's windows will be more than trim. As more cargo vehicles begin frequenting the space station, the station's robotic arm is going to be called into action to capture some of them as they approach and guide them into their docking port. Cupola will provide additional views for those operations.
NASA has been touting the delivery of the Tranquility node and its attached Cupola since last summer.
"This flight will, I think, grab the public's attention," said Kirk Shireman, ISS program deputy manager. "It's just going to be a really, really neat module for those on board. The dream of being able to go out and just have an unencumbered view of space - we'll have it. You can open up all the windows and look around and really feel like you're out there."