NASA's Mobile Launch Platform

The Mobile Launcher Platform or MLP is a two-story structure used by NASA, along with the Crawler-Transporter, to transport the Space Shuttle stack from the Vehicle Assembly Building (VAB) to either Launch Pad 39-A or 39-B at the Kennedy Space Center, as well as serve as the vehicle's launch platform. NASA's three MLPs were originally constructed for the Apollo Program to launch the Saturn V rockets in the 1960s and 1970s, and have remained in service to this day, with substantial alterations.