Two modules for the International Space Station are shown under construction recently at the Space Station manufacturing Facility at the Marshall Space Flight Center in Huntsville, Alabama. On the left is the airlock, which will be launched on STS-100 in August 1999. On the right is the U.S. Habitation Module, where the astronauts will live after it is launched to complete the station's orbital assembly in 2003. Assembly of the station will begin in the summer of 1998.