Live in Orbit: Girder freed from payload bay

Astronauts have freed a nearly 16-ton girder from shuttle Discovery's payload bay.

The 45-foot Starboard 6 truss has been lifted clear of the orbiter by the International Space Station's 57.5-foot robotic crane arm.

Arm operators John Phillips and Sandra Magnus are getting ready to hand off the truss segment to the shuttle's 45-foot arm, operated by the "A Team" of Tony Antonelli and Joe Acaba.

At that point, the station arm will relocate down a track to the starboard end of the outpost's central truss, or backbone.

The nearly $300-million S6 truss, built by the Boeing Co. is the 11th and final piece of that backbone, and the last major U.S.-built component to be installed on the station.

When complete, the backbone will measure 335 feet, or the length of a football field.

The final truss segment holds the station's last set of solar array wings, which will balance out the two sets on the station's port side when installed.

Discovery's crew joked that the station appeared "asymmetrical" as they approached for docking on Tuesday.

The new truss and arrays will make the station symmetrical with two sets of solar wings on each side, just as plans and artists renderings have pictured the orbiting science complex for years.

IMAGES: Click to enlarge any of these NASA TV images of the S6 truss being removed from shuttle Discovery's payload bay today.