CAPE CANAVERAL, Fla. -- In Orbiter Processing Facility-1 at NASA's Kennedy Space Center in Florida, workers guide the Orbiter Transporter System (OTS) under shuttle Atlantis for its move, or rollover to the nearby Vehicle Assembly Building (VAB).Once inside the VAB, Atlantis will be joined to its solid rocket boosters and external fuel tank on the mobile launcher platform. Later this month, Atlantis is scheduled to "rollout" to Launch Pad 39A on the STS-135 mission, which will deliver the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. STS-135, targeted to launch June 28, will be the 33rd flight of Atlantis, the 37th shuttle mission to the station, and the 135th and final mission of NASA's Space Shuttle Program.