Forrester works on the S3/S4 Trusses during EVA 4

S117-E-07755 (17 June 2007) --- Astronaut Patrick Forrester, STS-117 mission specialist, participates in the mission's fourth and final session of extravehicular activity (EVA), as construction continues on the International Space Station. Among other tasks, Forrester and astronaut Steven Swanson (out of frame), mission specialist, continued activation of the station's new starboard 3 and 4 (S3/S4) truss segment; checked out the Drive Lock Assembly 2, one of two mechanisms that will drive rotation of the S3/S4 Truss Solar Alpha Rotary Joint (SARJ); and removed the final launch restraints on the SARJ.