NASA's modified 747 Shuttle Carrier Aircraft is positioned under the Space Shuttle Discovery to be attached for their ferry flight to the Kennedy Space Center

NASA's specially modified 747 Shuttle Carrier Aircraft, or SCA, is positioned under the Space Shuttle Discovery to be attached for their ferry flight to the Kennedy Space Center in Florida. After its post-flight servicing and preparation at NASA Dryden in California, Discovery's return flight to Kennedy aboard the 747 will take approximately 2 days, with stops at several intermediate points for refueling.