Mission Specialists David Wolf and Piers Sellers began STS-112’s first spacewalk at 10:21 a.m. CDT (1521 GMT) today. Their main objective is to begin activating and outfitting the International Space Station’s newly installed S1 (S-One) Truss. The S1 was attached to the station earlier today by the station's robot arm.

Their tasks include connecting power and data cables between the station and S1, installing a camera and antenna assembly and releasing a number of launch estraints. They are slated to wrap up the spacewalk, which is based out of the station’s Quest Airlock, about 5 p.m. CDT (2200 GMT).

Wolf and Sellers are receiving assistance from inside Space Shuttle Atlantis and the station. STS-112 Commander Jeff Ashby and Pilot Pam Melroy are operating Atlantis’ robot arm. Melroy and Mission Specialist Fyodor Yurchikhin are coordinating spacewalk activities. STS-112 Mission Specialist Sandy Magnus and NASA ISS Science Officer Peggy Whitson are at the controls of the station robot arm.