The Space Shuttle Endeavour, mounted atop NASA's modified Boeing 747, flies above Griffith Park Observatory in Los Angeles on its final flight, on September 21, 2012. The retired space shuttle spent its last day in the air on a 5-hour flyover before landing at the Los Angeles International Airport, where it will stay for a few weeks before taking a slow-speed land journey across town through neighborhoods to its final museum home, the California Space Center. #

Back on August 11, 2011, retired space shuttles Discovery and Endeavour stop outside Orbiter Processing Facility-3 (OPF-3) at Florida's Kennedy Space Center for a unique photo opportunity. #

Inside Orbiter Processing Facility-2 at NASA's Kennedy Space Center in Florida, a United Space Alliance technician on a Hyster forklift guides replica shuttle main engine 2 toward space shuttle Endeavour as USA technicians in the aft area monitor the progress, on July 13, 2012. The work is part of Transition and Retirement of the remaining space shuttles, Endeavour and Atlantis. #

Workers escort space shuttle Endeavour as it is towed to the Mate-Demate Device, or MDD, at NASA's Kennedy Space Center in Florida after being backed out of the Vehicle Assembly Building on September 14, 2012. #

Space shuttle Endeavour is lifted into the mate-demate device at the Shuttle Landing Facility at Kennedy Space Center in Florida, on September 14, 2012. The shuttle will be positioned and connected to the top of NASA's Shuttle Carrier Aircraft, or SCA, with the aid of the device. #

United Space Alliance technicians prepare to uncover the cockpit windows on space shuttle Endeavour for an employee photo opportunity at the Shuttle Landing Facility in Florida, on September 16, 2012. #

Space shuttle Endeavour sits atop NASA's Shuttle Carrier Aircraft, at the Shuttle Landing Facility in the early morning hours at NASA's Kennedy Space Center on September 18, 2012. #

At the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, guests arrive by bus to view the space shuttle Endeavour, as preparations continue for the ferry flight to California. #

NASA's Shuttle Carrier Aircraft, with the space shuttle Endeavour mated on top, after taking off from Kennedy Space Center on September 19, 2012 in Cape Canaveral, Florida. #

Crowds gather around the space shuttle Endeavour, after landing at Ellington Field on September 19, 2012, in Houston. Endeavour stopped in Houston on its way from the Kennedy Space Center to the California Science Center in Los Angeles. #

Former U.S. Rep. Gabrielle Giffords and husband, former astronaut Mark Kelly, watch the Space Shuttle Endeavor fly over Tucson, Arizona, on its way to Los Angeles, on September 20, 2012. Kelly, Endeavour's last commander, requested that the shuttle pass over Tucson to honor Giffords, who is recovering after suffering a head wound in a shooting rampage last year. #

Elizabeth Danirjian, 5, of Santa Clarita, California, looks at Space Shuttle Endeavour atop NASA's Shuttle Carrier Aircraft after it landed at the NASA Dryden Flight Research Center at Edwards Air Force Base, California, on September 20, 2012. #

Space shuttle Endeavour and its modified 747 carrier aircraft soar over the Bay Bridge that connects San Francisco to Oakland during the final portion of its tour of California, on September 21, 2012. #

Space shuttle Endeavour and its carrier aircraft soar over the Golden Gate Bridge in San Francisco during the final portion of its tour of California, on September 21, 2012. #

Endeavour makes a low pass over Hangar One, at Moffett Field, in Mountain View, California. Original here. #

The space shuttle Endeavour passes over the Santa Monica Pier, on September 21, 2012 in Santa Monica, California. The pier offered free Ferris wheel rides during the flyover of the shuttle. #

Media personnel and hundreds of spectators wait with their cameras for space shuttle Endeavour to arrive at Los Angeles International Airport, in El Segundo, California, on September 21, 2012. Hundreds of people turned up as early as 6 am to secure a good viewing spot for the arrival of Endeavour. #

A crew member waves a U.S. flag as the SCA carrying Endeavour taxis to an airline maintenance hangar, at the conclusion of its last flight at Los Angeles International Airport, on September 21, 2012. #

This three-dimensional image (viewable with red/cyan glasses) at the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, shows the space shuttle Endeavour as it is being lifted in the mate-demate device. #

This 3D image (viewable with red/cyan glasses) shows a lift being used to support the space shuttle Endeavour, mounted atop NASA's Shuttle Carrier Aircraft, as it was being prepared for its ferry flight to California. #

This 3D image (viewable with red/cyan glasses) shows the space shuttle Endeavour, mounted atop NASA's Shuttle Carrier Aircraft, being prepared for its final flight to California. #