(05/30/2002) -- Lights define the Fixed Service Structure on Launch Pad 39A where Space Shuttle Endeavour, also bathed in light, sits ready for launch atop the Mobile Launcher Platform. Seen above the orange external tank behind Endeavour is the 'beanie cap,' or vent hood assembly at the end of the gaseous oxygen vent arm. STS-111 is the second Utilization Flight to the International Space Station, carrying the Multi-Purpose Logistics Module Leonardo, the Mobile Base System (MBS), and a replacement wrist/roll joint for the Canadarm 2. Also onboard Space Shuttle Endeavour is the Expedition 5 crew who will replace Expedition 4 on board the Station. The MBS will be installed on the Mobile Transporter to complete the Canadian Mobile Servicing System, or MSS. The mechanical arm will then have the capability to 'inchworm' from the U.S. Lab Destiny to the MSS and travel along the truss to work sites. Expedition 4 crew members will return to Earth with the STS-111 crew on Endeavour. Launch is scheduled for 7:44 p.m. EDT, May 30, 2002