Countdown starts for shuttle launch tomorrow

Countdown clocks at the Kennedy Space Centre in Florida began ticking for tomorrow's launch of space shuttle Endeavour on a mission to deliver a porch to the International Space Station.

The platform will complete Japan's elaborate three-part Kibo laboratory complex, the station's newest and largest module.

"This has been a long journey for us and our Japanese colleagues," said Scott Higginbotham, who oversees station payloads at Nasa's Florida launch site.

For about six years, Japanese space agency technicians have worked side-by-side with Nasa personnel in Florida to prepare Kibo. The first two sections of the lab were launched last year.

The team, which peaked at about 40 to 50 people, will be returning to Japan after Endeavour's launch.

The shuttle and its seven-member crew is scheduled to lift off at 1117 GMT tomorrow for a 16-day mission.

The astronauts plan to conduct five spacewalks to hook up Kibo's new porch, replace batteries on one of the station's solar panel wings and to position spare parts on platforms outside the station.

The porch is a platform for experiments that require direct exposure to space.

"We are so ready to go, we just can't wait," Thomas Marshburn, one of Endeavour's four rookie astronauts, said after the crew arrived in Florida for final launch preparations.

Nasa hopes to get Endeavour on its way to the station by Monday so it can proceed with launch of a lunar probe that is expected to map the moon's surface in preparation for a human landing in 2020.