Sitting atop the Mobile Launcher Platform Space Shuttle Atlantis inches its way to the launch pad.

Sitting atop the Mobile Launcher Platform, Space Shuttle Atlantis inches its way to the launch pad. The Shuttle and MLP rest on top of the crawler-transporter beneath it, which moves about 1 mile per hour. Atlantis is scheduled for launch April 4 on mission STS-110, which will install the S0 truss, the framework that eventually will hold the power and cooling systems needed for future international research laboratories on the International Space Station. The Canadarm2 robotic arm will be used exclusively to hoist the 13-ton truss from the payload bay to the Station. The S0 truss will be the first major U.S. component launched to the Station since the addition of the Quest airlock in July 2001. The four spacewalks planned for the construction will all originate from the airlock. The mission will be Atlantis' 25th trip to space