Astronauts Open Space Station's Newest Room

The International Space Station just got roomier. Astronauts opened the orbiting laboratory?s brand-new room late Friday and quickly got to work moving things in.

The new Node 3 module, named Tranquility in honor of NASA?s Apollo 11 moon base, was opened with little fanfare at 9:17 p.m. EST (0217 Saturday GMT) by all 11 astronauts on the linked space station and shuttle Endeavour.

?Houston, Node 3 is open,? Endeavour pilot Terry Virts radioed to Mission Control. ?It looks really nice in there and we?re getting back to work.?

The new module and its seven-window observation deck launched to the station on Monday aboard the shuttle Endeavour, which arrived at the orbiting laboratory two days later.

It was installed the nearly 24-foot (7-meter) long room during a spacewalk that began late Thursday, but the astronauts did not hook up the vital cooling system plumbing needed to fully activate the new room. That comes during the next spacewalk set for late Saturday.

The astronauts used flashlights Friday to see inside the dark Tranquility module. They wore goggles and face masks as protection against any dust or debris that had shaken loose during the module?s trip to space.

"The module looks beautiful and the atmosphere is very clean," said station commander Jeffrey Williams of NASA.

Williams said he saw no dust or debris after opening the station?s newest room. He and his crewmates will hook up power lines and water hoses, and are expected to move the first large pieces ? a big exercise machine and an air recycling system ? into Tranquility overnight.

The $382 million Tranquility module and observation deck, called the Cupola, are NASA?s last major additions for the space station. They are attached to the left side of the station?s central Unity node.

With them installed, the space station is now 98 percent complete and weighs nearly 800,000 pounds (362,873 kg). The $100 billion space station has been under construction since 1998 and is the result of cooperation by 16 different countries.

The seven-window Cupola includes a huge round central window that is the largest space window ever launched.

The $27.2 million window set was to be opened late Friday for just a short while, and then shut tight again until it can be moved from the end of Tranquility to an Earth-facing berth. NASA has said it will provide unparalleled panoramic views of the planet from space.

The orbital work to activate Tranquility came just hours after NASA cleared the shuttle Endeavour?s heat shield of any concerns.

Three minor defects in the shield, spotted in photographs of the nose and left wing, are too small to pose any damage risk to the orbiter.

NASA has kept a close watch on shuttle heat shield health since a piece of debris led to the destruction of shuttle Columbia during re-entry in 2003. A final, standard inspection of Endeavour's heat shield will be conducted by shuttle astronauts once the orbiter leaves the station next week.

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SPACE.com is providing complete coverage of Endeavour's STS-130 mission to the International Space Station with Managing Editor Tariq Malik and Staff Writer Clara Moskowitz based in New York. Click here for shuttle mission updates and a link to NASA TV.