CAPE CANAVERAL, Fla. (AP) - The International Space Station is about to get bigger. On Tuesday morning, the visiting Atlantis astronauts will attach a Russian-built compartment to the space station.

The shuttle delivered the 20-foot chamber, which is stuffed with supplies. The construction work is being squeezed between spacewalks. Two of the shuttle astronauts performed a spacewalk Monday. They installed a spare antenna and loosened bolts on six batteries that will be plugged in during the next two spacewalks.

Engineers are analyzing a tiny gap between the newly installed antenna and its boom. Mission Control may ask the astronauts to do some extra work on the antenna. They also may be asked to untangle a cable on the shuttle's inspection boom.