The shuttle carrier aircraft or SCA and its piggyback passenger Atlantis taxi down the runway.

The shuttle carrier aircraft, or SCA, and its piggyback passenger Atlantis taxi down the runway after landing at the KSC Shuttle Landing Facility. Touchdown was at 8:27 a.m. EDT. The SCA is a modified Boeing 747 jetliner. Visible on Atlantis is the tail cone that covers and protects the main engines during the ferry flight. Atlantis landed at Edwards Air Force Base in California to end mission STS-117. The return to KSC began July 1 and took three days after stops across the country for fuel. The last stop was at Ft. Campbell in Kentucky. Weather conditions over the last leg postponed the return trip until July 3. Atlantis will be removed from the back of the SCA via the mate/demate device at the SLF. It will then be towed to the Orbiter Processing Facility to begin processing for its next launch, mission STS-122 in December. Photo credit: NASA/Jim Grossmann