This closeup shows Space Shuttle Discovery as it travels to Launch Pad 39B.

This closeup shows Space Shuttle Discovery as it travels to Launch Pad 39B. Underneath Discovery is the Mobile Launcher Platform, a two-story movable launch base. Part of the MPLM is the tail service mast, seen here at the bottom of the wind and next to the Shuttle’s main engines. The tail service mast is 31 feet high, 15 feet long and 9 feet wide. A second TSM is on the other side. They support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft T-0 umbilicals. Discovery will be flying on mission STS-102 to the International Space Station. Its payload is the Multi-Purpose Logistics Module Leonardo, a “moving van,” to carry laboratory racks filled with equipment, experiments and supplies to and from the Space Station aboard the Space Shuttle. The flight will also carry the Expedition Two crew up to the Space Station, replacing Expedition One, who will return to Earth on Discovery. Launch is scheduled for March 8 at 6:45 a.m. EST