the 2003 Columbia tragedy.

The main part of the Kibo lab will fly on the next shuttle mission in May, with the final installment, a porch for outdoor experiments, going up next year.

Altogether, the Japanese Space Agency has invested about $6.7 billion in the space station program, including a Kibo control center near Tokyo.

Canada's $200 million-plus Dextre, meanwhile, is designed to eventually take over some of the more routine outdoor maintenance chores from spacewalking astronauts. Dextre, short for dexterous and pronounced like Dexter, will join the space station's Canadian-built robot arm, already in orbit for seven years.

In addition to working with their international payloads, Endeavour's astronauts will try out a caulking gun and high-tech goo on deliberately damaged shuttle thermal tile samples. The test - part of NASA's ongoingpost-Columbia safety effort - should have been performed last year, but was put off because of emergency space station repairs.

Astronaut Garrett Reisman will stay behind on the space station until June, swapping places with a Frenchman who accompanied Europe's Columbus lab into orbit in February.

A Japanese astronaut is also part of Endeavour's all-male crew.

Endeavour's countdown was the smoothest in years, officials said. Shortly after liftoff, however, the astronauts had to deal with a couple of problems that ended up being minor. They got alert messages for some of their ship's steering thrusters, but it turned out to be a bad electronics card. Then the primary cooling system failed, and they had to switch to the backup.

A cursory look at the initial launch images - fewer than usual because