(09/24/1999) -- From the Shuttle Landing Facility at Kennedy Space Center, the orbiter Columbia moves down the runway on the back of a Boeing 747 Shuttle Carrier Aircraft on a ferry flight to Palmdale, Calif. On the rear of the orbiter can be seen the tail cone, a fairing that is installed over the aft fuselage of the orbiter to decrease aerodynamic drag and buffet when the Shuttle Carrier Aircraft is transporting the orbiter cross-country. It is 36 feet long, 25 feet wide, and 22 feet high. Columbia, the oldest of four orbiters in NASA's fleet, will undergo extensive inspections and modifications in Boeing's Orbiter Assembly Facility during a nine-month orbiter maintenance down period (OMDP), the second in its history. Orbiters are periodically removed from flight operations for an OMDP. Columbia's first was in 1994. Along with more than 100 modifications on the vehicle, Columbia will be the second orbiter to be outfitted with the multifunctional electronic display system, or 'glass cockpit.' Columbia is expected to return to KSC in July 2000