During the 12-day stay at the orbital outpost, astronauts performed five spacewalks, which are the most ever done in single shuttle mission visiting the station.

They successfully assembled the two-armed robot, attached Kibo's first room to a planned place, and did some other chores for the station.

Spacewalkers devoted the first three spacewalks to assembling the robot, named Dextre, outside the station. In the future, Dextre can take over some routine maintenance tasks that have been performed by spacewalkers, enabling astronauts to devote more time to experiments and other scientific activities inside the space station.

The fourth spacewalk focused on testing a method for repairing damaged shuttle heat shield tiles, while the fifth involved stowing an inspection boom on the station.

In the meantime, Endeavour crew, along with Expedition 16 crew at the station, attached Kibo's first component to the station and transferred supplies from the shuttle's cargo bay into it.

Kibo, which means Hope in Japanese, is such a huge orbital lab that NASA arranges three shuttle flights to carry every parts to the space station. This first part serves as a storage compartment, and the main part of the lab is scheduled to launch on the next shuttle mission in late May. The final section, an outdoor porch with robotic arms, is due to fly next year.

In addition to the grueling construction work, Endeavour also delivered a new resident for the station. Endeavour astronaut Garrett Reisman switched places with Expedition 16 Flight Engineer Leopold Eyharts, who returned to Earth aboard the shuttle.

With every assignment on the list perfectly accomplished in such an intense construction mission, LeRoy Cain, chairman of the mission management team at NASA described Endeavour's STS-123 as "a textbook mission".

This is NASA's second shuttle flight in 2008. NASA's three service shuttles will all be retired by 2010. Therefore, it hopes to finish the construction of the 100-billion-dollar space station before that deadline.

(Xinhua News Agency March 27, 2008)