Astronauts maneuver Japan's new robot arm in space

By Irene Klotz

HOUSTON, June 7 (Reuters) - Astronauts aboard the International Space Station maneuvered a new Japanese robot arm for the first time on Saturday while crewmates prepared for The final spacewalk of U.S. shuttle Discovery's two-week mission.

The 33-foot (10-metre) crane is attached to the front of Japan's newly arrived Kibo research laboratory, the biggest and most elaborate of the $100 billion space station's nine rooms.

It will be used to tend to science experiments anchored on a platform and exposed to the open environment of space. The platform is scheduled to be launched on another shuttle mission to the space station next year, more than 200 miles (320 km) above Earth.

"We have our own house here now," Japanese astronaut Akihiko Hoshide said during an inflight interview on Saturday. "It's a big milestone."

Installing and outfitting the 37-foot- (11-metre-)long Kibo is the primary goal of Discovery's mission, the 26th of 35 planned shuttle flights devoted to space station assembly and servicing. The shuttle arrived at the station last Monday and is scheduled to depart on Wednesday.

While Hoshide and robot arm operator Karen Nyberg unfolded Kibo's crane for the first time, moving it slightly to make room for more work on Kibo's exterior, spacewalkers Michael Fossum and Ronald Garan checked their spacesuits and prepared equipment for a third and final spacewalk on Sunday.

The astronauts plan to take a protective cover off of Kibo's front window, remove locks that secured the delicate robot arm during launch and replace a nitrogen tank used to pressurize ammonia for the station's cooling system.

Flight directors also added an inspection of a joint that pivots the station's solar wing panels to track the sun for power. One of the two joints is contaminated with metal shavings and NASA wants to double-check the condition of the second one, located on the station's port or left side.

Fossum looked at the gear during the mission's second spacewalk on Thursday and noted a thin layer of grease on a metal ring that guides the joint's bearings.

"It was not expected," Fossum said.

Analysis of photographs also revealed what looks like a bit of dust or deposit on the ring. Fossum plans to collect a sample of any debris on a piece of tape during Sunday's spacewalk.

All in all, he added, "that bearing looks to be in pretty darn good shape." (Editing by Tom Brown and Eric Walsh)