Space Shuttle Atlantis in High Bay 4 of the Vehicle Assembly Building backed out and took Space Shuttle Discovery's place in Orbiter Processing Facility-1 (OPF-1).br br Shuttle Discovery then backed out of OPF-1 to let Atlantis in.br br Discovery has completed her retirement process and will wait out in the VAB until her ferry flight to her final resting place - The Smithsonian Museum.