CAPE CANAVERAL, Fla. — In terms of both size and sophistication, Japan is about to roll out the Lexus of space labs.

The $1 billion Kibo, which means "hope" in Japanese, is poised for a Saturday launch aboard the space shuttle Discovery. It will be the biggest and by far the most elaborate module on the International Space Station — an 11-meter-long scientific workshop as large as a school bus, with its own hatch to the outside for experiments and a pair of robot arms. Making it even bigger will be a closet and porch.

Kibo is so enormous that three shuttle flights are needed to get it all up.