Space shuttle Endeavour astronauts get their ship ready for a Wednesday landing as they neared the end of what NASA hailed as a landmark mission.

"Here we are nine years, three months-plus later and we now have all the international partners represented on board the ISS (space station)," NASA space station program manager Mike Suffredini said in a Monday night press briefing at Johnson Space Center.

Endeavour, which launched on March 11 and spent 12 days at the space station before departing on Monday, was scheduled to land at 7:05 p.m. EDT on Wednesday at Kennedy Space Center in Florida.

The shuttle crew performed five spacewalks, with much of their time devoted to the assembly of Dextre, the Canadian robot that will be used to perform maintenance on the station exterior.

But their primary task was to install the first piece of Japan's three-piece Kibo complex, which will be the largest laboratory on the space outpost when completed early next year.

After delivering the first Japanese module to the International Space Station and assembling a Canadian robot for station maintenance, the seven crew members were to stow gear and check flight control systems to prepare for their fiery descent back to Earth.