Astronauts on the Space Shuttle Discovery and the International Space Station were united today, and the joint crew immediately began the complex work associated with installing a new truss section and rewiring the station's power grid.

Discovery's crew entered the station complex at 5:54 p.m. CST as Expedition 14 Commander Michael Lopez-Alegria rang the on-board ship's bell, a centuries-old naval tradition. Lopez-Alegria and crewmates Mikhail Tyurin and Thomas Reiter greeted Discovery Commander Mark Polansky, Pilot Bill Oefelein and Mission Specialists Nicholas Patrick, Joan Higginbotham, Bob Curbeam, Sunita Williams and Christer Fuglesang with smiles and hugs. The warm welcome followed a 4:12 p.m. rendezvous and docking.

Before launching into their first joint task of the mission -- extracting the new P5 truss member from Discovery's cargo hold -- the combined crew was called upon to conduct an impromptu inspection of the tip of Discovery's port wing using the space station's robotic arm. The inspection was precipitated by a minor vibration reading on a wing sensor in that area about 4:30 a.m. Monday.

Though the single reading could indicate an on-orbit impact, it was not unusual and mission managers did not expect to find any damage. End-effector camera views will allow imagery analysts in Houston to verify that the reinforced carbon-carbon panels on the wing's leading edge are unscathed. The imagery analysis team also began to review pictures taken of Discovery's belly during its approach to the station. Teams will meet overnight to determine if a final inspection of the orbiter's tiles is needed.

The added task delayed unberthing of the 4,100-pound truss section about an hour. But once the inspection was complete, the crew used the shuttle's robotic arm to pull the truss section out of the payload bay and hand it to the station arm. The P5 truss will remain suspended over Discovery's port wing overnight, awaiting installation in the first of three planned spacewalks tomorrow.

Before going to bed, the crews gathered for a thorough review of the plan for tomorrow's spacewalk. Curbeam and Fuglesang will spend tonight in the station's airlock, where pressure will be reduced to 10.2 psi. The airlock ?campout? will purge the spacewalkers' bloodstreams of nitrogen bubbles and protect against decompression sickness as the two go to the even lower pressure of spacesuits on Tuesday.

Discovery's crew is scheduled to awaken at 9:47 a.m. CST Tuesday, and the Expedition 14 crew at 10:17 a.m. The spacewalk is to begin at 2:22 p.m., with truss installation expected at 4:07 p.m.

The next STS-116 status report will be issued Tuesday morning or earlier if events warrant.

News from Commercial Space Watch