ISS006-307-012 (15 January 2003) --- Astronaut Donald R. Pettit, Expedition 6 NASA ISS science officer, performs P1 (P-One) Truss nadir launch lock releases on the International Space Station (ISS) during a session of extravehicular activity (EVA). Astronaut Kenneth D. Bowersox (out of frame), mission commander, joined Pettit on the spacewalk.