MARCIA DUNN

The Associated Press

CAPE CANAVERAL, Fla. (AP) -Buoyed by a good weather forecast, space shuttle Endeavour and its seven astronauts aimed for a Friday morning landing to end their successful space station construction mission.

Endeavour was scheduled to touch down at 10:48 a.m. In preparation, the shuttle's payload bay doors were closed right on time as the sun rose at the Kennedy Space Center in a somewhat hazy sky.

Mission Control had encouraging words for the crew, but noted it was keeping an eye on thunderstorms offshore, to the southeast.

"All right, we will keep our fingers crossed," said shuttle commander Mark Polansky.

While visiting the international space station, the astronauts put on a new addition to Japan's $1 billion lab, installed fresh batteries, and stockpiled some big spare parts. They were part of the biggest gathering ever in space. Counting the six station residents, the crowd totaled 13.

The shuttle mission has lasted 16 days. But it was the 138th day in orbit Friday for Japanese astronaut Koichi Wakata, who moved into the space station last March. He swapped places with American Timothy Kopra, who rode up on Endeavour.

Wakata said he's yearning for some sushi, as soon as he's back on the planet, and a soak in a hot spring once he's back in Japan. At the top of his list, though, is seeing his wife and son.

The shuttle astronauts carried out five spacewalks tying a record for a single flight and helped their station colleagues when a toilet flooded and an air purifier overheated. The commode, one of three on the linked shuttle and station, was fixed in a day. But the air-cleansing system is out of order.

Japan's Kibo lab which means Hope got a front porch for outdoor experiments during Endeavour's visit. An X-ray telescope and space environment monitor were installed on the porch, along with communication equipment.

The mission concluded work on the lab the largest one at the orbiting outpost that spanned more than a year and three shuttle flights. Next up for the Japanese will be the debut launch in September of an unmanned cargo ship.

As for NASA, seven shuttle flights remain to finish the space station, now 83 percent complete with nearly 700,000 pounds of mass. The next launch, by Discovery, is targeted for the end of August.

On the Net:

NASA: http://www.nasa.gov/mission(underscore)pages/shuttle/main/index.html