ISS006-E-08610 (18 December 2002) --- Astronaut Donald R. Pettit, Expedition Six NASA ISS science officer, looks over a procedures checklist in the Zvezda Service Module (SM) on the International Space Station (ISS). Pettit went on to complete the scheduled Week 3 potable water sampling and on-orbit chemical/microbial analysis of the SM environment control and life support system.