CAPE CANAVERAL, Fla. - NASA has given space shuttle Endeavour clearance for liftoff in less than two weeks on what will be the longest shuttle visit ever to the international space station.

Endeavour is scheduled to blast off a week from Tuesday on a 16-day mission that could be extended by an additional day.

Space agency officials say it will be a long and complicated flight, packed with five spacewalks, installing major space station components from Japan and Canada.

Endeavour will be carrying up the first part of Japan's massive Kibo lab and a Canadian two-armed robot that eventually will take over some of the spacewalking chores.

The space agency faces a 2010 deadline for completing the 12 remaining shuttle flights.

Eleven of them are delivery and construction trips to the space station.