MS Mastracchio working on the S1 Truss during EVA 3 for Expedition 15 / STS-118 Joint Operations

ISS015-E-22539 (15 Aug. 2007) --- Astronaut Rick Mastracchio, STS-118 mission specialist, participates in the mission's third planned session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the 5-hour, 28-minute spacewalk, Mastracchio and astronaut Clay Anderson (out of frame), Expedition 15 flight engineer, relocated the S-Band Antenna Sub-Assembly from Port 6 (P6) to Port 1 (P1) truss, installed a new transponder on P1 and retrieved the P6 transponder.