Space Shuttle Atlantis and the STS-117 crew arrived at the International Space Station at 3:36 p.m. EDT, delivering a new truss segment and crew member to the orbital outpost.

The STS-117 astronauts and the station’s Expedition 15 crew conducted pressure and leak checks before the hatches between the spacecraft were opened. After the crews greeted each other, they quickly began joint operations.

One of the first major tasks is the station crew rotation. STS-117 Mission Specialist Clayton Anderson will switch places with Expedition 15 Flight Engineer Suni Williams, who will be wrapping up a six-month tour of duty on the station. Anderson is scheduled to stay on the station until he returns to Earth with STS-120 later this year.

Anderson will officially become a member of Expedition 15 when his custom-made seat liner is swapped out with Williams’ in the Soyuz spacecraft docked to the station.

The crews will prepare for Monday’s installation of the Starboard 3 and 4 (S3/S4) truss segment and the first of three scheduled STS-117 spacewalks. The crews will use the shuttle robotic arm to lift the S3/S4 out of Atlantis’ payload bay and hand it off to the station arm.

The S3/S4, which contains a new set of solar arrays, is scheduled to be attached to the station at 11:08 a.m. Monday. Then, STS-117 Mission Specialists John “Danny” Olivas and Jim Reilly will make connections between the station and the new truss segment during the spacewalk, which is set to kick off at 2:53 p.m.

About an hour before docking, Sturckow and Archambault guided the shuttle through a back-flip maneuver that allowed the Expedition 15 crew to photograph the shuttle’s protective heat-resistant tiles. The imagery will be sent to engineers on Earth for analysis.

STS-117 is the 21st shuttle mission to visit the station. Atlantis scheduled to undock June 17 and return to Earth on the 19th.