Cassidy at the P1 Truss during EVA-3

S127-E-007954 (22 July 2009) --- Astronaut Christopher Cassidy, STS-127 mission specialist, participates in Endeavour's third space walk of a scheduled five overall for this flight. This was Cassidy's first of a scheduled three sessions for him. Astronaut Dave Wolf, Cassidy's EVA colleague, is out of frame.