Starting next month, NASA will begin delivering its four Space Shuttle orbiters to their final destinations. After an extensive decommissioning process, the fleet -- which includes three former working spacecraft and one test orbiter -- is nearly ready for public display. On April 17, the shuttle Discovery will be attached to a modified 747 Jumbo Jet for transport to the Smithsonian's National Air and Space Museum in Virginia. Endeavour will go to Los Angeles in mid-September, and in early 2013, Atlantis will take its place on permanent display at Florida's Kennedy Space Center. Test orbiter Enterprise will fly to New York City next month. Gathered here are images of NASA's final days spent processing the Space Shuttle fleet.