Shuttle Discovery's astronauts wrapped up their few remaining chores at the international space station on Monday, flexing the robot arm belonging to the newly installed Japanese science lab and opening its attic.

The two crews planned on saying "sayonara" Tuesday, with Discovery heading out first thing Wednesday morning.

Japan's billion-dollar Kibo lab — which means hope — had the door to its attic swung open. The storage closet, in orbit for three months, was attached to the lab late last week.

In addition, Kibo's robot arm was extended to its full 33 feet, with all six joints tested. At the end of the workout, the arm was folded into a long-term resting position.

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Japanese astronaut Akihiko Hoshide made sure that his Tokyo-based flight controllers got to see Kibo's arm in action.

"It was such a pretty view, we just wanted to share it with you guys," Hoshide said.

The view from a video camera on the station showed the arm extended with the bright blue Earth in the background.

"Great job," Japanese flight controllers said after the testing was successfully completed.

At the end of the test, the arm was folded up and stored, out of the way of the lab's windows.

Kibo's arm will be used to handle outdoor science experiments once a porch, the third and final section of the lab, is launched next year.

A 7-foot robot arm will be sent up then as well. Kibo is already the biggest room at the space station.

All 10 space travelers posed for a group shot inside Kibo, a sparkling white and blue chamber the size of a bus.

"Three, two, one, cheese," radioed Mission Control, which froze the TV image on a huge screen. "We got it. Beautiful. Well executed, Discovery."

Discovery delivered Kibo to the space station a week ago, along with a new space station resident, Gregory Chamitoff. He traded places with Garrett Reisman, who's leaving after a three-month stay. Chamitoff's mission will last twice that long.