The US space shuttle Endeavour has landed successfully in Florida after the longest mission of its kind to the International Space Station.
Endeavour's descent was slightly delayed by poor weather at the Kennedy Space Center.
During their 16-day mission, the space shuttle's crew installed the first part of a Japanese research laboratory and assembled a Canadian robot.
The robot will carry out maintenance on the exterior of the space station.
The installation of the Japanese contribution means that nine years after platform construction began, all 15 partner nations are now represented in the $100bn (£50bn) ISS project.
The next shuttle visit to the ISS is scheduled for late May, when Discovery is due to arrive with the main part of the bus-sized Japanese laboratory, Kibo.
"This has been a two-week adventure and it's been a pleasure and honour to be on it," Endeavour pilot Greg Johnson told Mission Control in Houston on Wednesday.
"In a bittersweet way, we're ready to get home."
Onboard Endeavour was also the French astronaut Leopold Eyharts, who spent seven weeks on the ISS setting up Europe's new Columbus laboratory and running the first set of experiments. Garrett Reisman has replaced him.
After the space shuttle undocked from the ISS on Monday after 12 days, the chairman of Nasa's mission management team, LeRoy Cain, said it had been "textbook mission up and down the line".
Nasa has 10 more construction and resupply missions to the space station planned before the end of 2010 when its shuttle fleet is due to be retired. The four orbiter missions remaining this year include one flight to service the Hubble Space Telescope.