The perfect landing of the space shuttle Endeavour has concluded the STS-123 mission, during which the astronauts have spend more than 16 days in space, assembling the first component of the Kibo laboratory and Dextre, the Canadian robot.

In a flawless landing,  Endeavour touched down at 8:39 p.m. EST Wednesday at NASA's Kennedy Space Center in Florida.

"I got to talk to the crew, and the crew was just having a fantastic time reflecting on their mission and looking up at their vehicle that just landed," said Shuttle Launch Director Mike Leinbach. "They were glad to be home, very proud of the work they did, and we're very proud of the work they did, too." The astronauts begun their mission on March 11 and arrived at the at the International Space Station March 12.

During their stay at ISS, they have conducted five spacewalks. The first three spacewalks were intended to install the Japanese Logistics Module - Pressurized Section (JLP), the first pressurized component of the Kibo laboratory to the station and the final element of the station's Mobile Servicing System, the Canadian-built Dextre, also known as the Special Purpose Dextrous Manipulator.

During the last two spacewalks, the astronauts have tested a shuttle tile repair material. The repair material test was originally scheduled for Discovery’s mission last October, but was rescheduled so that problems with the station’s solar arrays could be addressed.

For the Japanese Aerospace Exploration Agency (JAXA) the STS-123  was merely the beginning.

"We are quite honored that Mr. Doi contributed to the construction of the space station," said JAXA vice president Kaoru Mamiya, referring to STS-123 Mission Specialist Takao Doi. "It's the first step for our Kibo construction, and we hope that next time, the main module will be added to the station."

Endeavour and crew are in excellent shape after a safe and successful landing, according to NASA managers.

The next mission is the STS-124, the second of three flights that will launch components to complete the Kibo laboratory. The mission, which is scheduled to begin on May 25, will include two spacewalks to install the new lab and its remote manipulator system. The lab's logistics module, which will have been installed in a temporary location during STS-123, will be attached to the new lab.

Navy Cmdr. Mark E. Kelly will command the STS-124 shuttle mission and Navy Cmdr. Kenneth T. Ham will serve as the pilot. Mission specialists will include NASA astronauts Karen L. Nyberg; Air Force Col. Ronald J. Garan Jr.; and Air Force Reserve Col. Michael E. Fossum. Japan Aerospace Exploration Agency (JAXA) astronaut Akihiko Hoshide also will serve as a mission specialist.