The space shuttle Discovery returned to its base in Florida Saturday after a $57 million, nine-month refit that will allow it to dock with Russia's Mir and NASA's planned international space station.
Discovery landed at the Kennedy Space Center riding piggyback atop a specially modified Boeing 747.The $2 billion reusable spaceship has spent the past nine months in a hangar owned by shuttle manufacturer Rockwell (ROK.N) in Palmdale, Calif.
During the tuneup, 106 modifications were made and the shuttle orbiter was thoroughly checked for signs of corrosion and metal fatigue.
The largest single modification was to move the shuttle's airlock from the crew cabin to the 60-foot cargo bay to permit dockings with Mir and the international space station.
Until now, Atlantis was the only shuttle equipped for space station dockings. Shuttle Endeavour is to undergo similar modifications later this year.