View of Astronaut Heidemarie M. Stefanyshyn-Piper, Mission Specialist MS in the white striped Extravehicular Mobility Unit EMU, releases photovoltaic radiator PVR cinches and winch Push in Pull PIP pins on the P3/P4 Truss during Extravehicular Activity EVA. View shows the FWD side of the P1 and P3/P4 Trusses with the Mobile Base System MBS.