Live in Orbit: Truss Handoff Complete

Today's first orbital handoff of a giant girder between two robotic crane arms is complete.

The girder, known as the "S6" or Starboard 6 truss, is now in the hands of shuttle Discovery's 45-foot crane.

The International Space Station's 57.5-foot crane began lifting the 31,000-pound truss from the shuttle's payload bay at 11:45 a.m. and handed it off around 1:40 p.m.

Now the station crane must slide along a track to the starboard end of the outpost's central backbone to get in position to receive the truss again.

The second handoff is expected around 6 p.m.

After that, the truss will be "parked" overnight.

The parked position best manages the mass of the truss and protects it from temperature swings on orbit.

It also prepares the truss for installation on Thursday during the mission's first spacewalk.