This is a Space Shuttle STS-100 mission onboard photograph. Astronaut Scott Parazynski totes a Direct Current Switching Unit while anchored on the end of the Canadian-built Remote Manipulator System (RMS) robotic arm. The RMS is in the process of moving Parazynski to the exterior of the Destiny laboratory (right foreground), where he will secure the spare unit, a critical part of the station's electrical system, to the stowage platform in case future crews will need it. Also in the photograph are the Italian-built Raffaello multipurpose Logistics Module (center) and the new Canadarm2 (lower right) or Space Station Remote Manipulator System.