Japanese lab attached to space station

By Ed Stoddard and Irene Klotz

HOUSTON (Reuters) - A pair of astronauts on Tuesday completed the first of three scheduled spacewalks on a mission by U.S. shuttle Discovery to install a huge Japanese research lab at the International Space Station.

Conducted by veteran spacewalker Michael Fossum and his rookie partner, Ronald Garan, the outing went smoothly for the most part and lasted six hours and 48 minutes.

The primary goal of Discovery's mission, which began Saturday with liftoff from the Kennedy Space Centre in Florida, was to deliver Japan's $1 billion (509 billion pound) Kibo laboratory, the cornerstone of that country's 20-year effort to join in as a permanent player in human space exploration and research.

Describing Tuesday's activities as they were set to unfold 210 miles above Earth on the 43rd anniversary of the first U.S. spacewalk, space station flight director Emily Nelson called it "a really big day for Japan."

The spacewalkers prepared the lab for installation, retrieved a sensory inspection boom and scraped some debris off a metal ring on one of the orbital outpost's solar power wing panels.

As the spacewalk wrapped up, astronauts working from inside the station used the station's robot arm to attach the Kibo lab onto the Harmony module, which serves as a connecting node for several station components.

At 37 feet long and just over 14 feet wide, Kibo, which means "Hope," is so big that Discovery didn't have room in its cargo bay for its inspection boom, a piece of equipment that doubles the length of the shuttle's 50-foot robot arm so that cameras and sensors can inspect the ship's wings and nosecap for damage.

The boom was part of NASA's safety upgrades following the fatal 2003 Columbia accident, which was triggered by damage from a debris impact.