The spaceshuttle Discovery will be at Barksdale Air Force Base Sunday night. After the stop, the shuttle will fly to Florida atop a modified 747. Its been at the Mojave Desert facility since it returned home last Sunday from a 13-day mission to the International Space Station. It took to the skies shortly after 6 Sunday morning atop a modified 747 dubbed the Shuttle Carrier. It will make two stops, one to refuel in Amarillo, Texas, and the other for an overnight rest in the ArkLaTex.