CAPE CANAVERAL - In a big room at Kennedy Space Center, cylindrical labs and plastic-draped trusses surround a 17-ton space girder whose time to fly has come.

It's not particularly pretty, with its hexagonal frame, bouquets of wires and squat batteries, but this two-truss combo is the first big piece of the International Space Station to be brought there in nearly four years.

This morning, a super-crane lifted the linked P3/P4 truss segments -- designated "P" for their port or left-side location -- and placed them in their canister.

"I always love to see that," said Boeing site manager Chuck Hardison of Merritt Island, who has waited a long time to see it go. "It's like a ship going down the channel. It's so big, and it moves so gracefully."

In turn, the cargo will head to the pad for a launch aboard Atlantis targeted for Aug. 28. The orbiter is set to roll to the Vehicle Assembly Building at Kennedy Space Center on Monday and to the launch pad July 31.

"The shuttle is flying again, and we're excited and anxiously awaiting our turn at the end of August," said Robbie Ashley, NASA's manager for the cargo.

The last true station construction mission was in late 2002, before the 2003 Columbia accident grounded the shuttles and prompted a round of design changes.

In the interim, astronauts have taken several spacewalks, making repairs and performing other tasks on the station, but no large equipment has been installed.

The truss will add another set of solar panel wings. Tests gave managers confidence that, after issues with sticky panels in the past, these will unfold despite their long storage.

The batteries have been replaced because NASA feared they wouldn't be able to store and distribute power as expected.

"They were never intended to be on the ground this long," Hardison said.

Perhaps one of the most impressive parts of the linked segments is the 10-foot-wide Solar Alpha Rotary Joint in the middle, which keeps the solar panels aimed at the sun.

"The entire space station outboard of that joint will be rotating 360 degrees every orbit," Hardison said. "It'll be quite something to see, that's for sure."

He said his team was eager to get the hardware into orbit as they waited for the shuttle schedule to pick up again. Among the many parts awaiting flight are the Japanese Experiment Module, Europe's Columbus Laboratory and a starboard truss that will mirror the port pieces about to fly.

"We worked on it for so long," Hardison said.

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