10/31/2007. Remarks by Johan Visschedijk: "This aircraft was built for American Airlines and was first flown, registered as N9668, on October 15, 1970. It was acquired by the NASA on July 18, 1974, registered N905NA, and initial used at Dryden Flight Research Center to investigate the problems associated with wake vortex flow from wide-body jets. In April 1976 it was delivered to Boeing and converted to the Shuttle Carrier Aircraft (SCA).

The first flight with the shuttle attached on top was made on February 18, 1977. On August 13, 1977, the shuttle was launched from the SCA to glide to an un-powered landing at Edwards AFB, California. When after a mission the shuttle is forced to land at Edwards AFB, due to bad weather conditions in Florida, the SCA is to carry the shuttle home.

The visible external modifications are the addition of the single forward and two aft support assemblies for attachment of the shuttle and the two fins attached to the tips of the tail plane.

10/31/2012. The final ferry flight scheduled in the Space Shuttle Program era took place September 19-21, 2012. On September 19, Shuttle Carrier Aircraft N905NA, with space shuttle Endeavour mounted on its back, left Kennedy Space Center, Florida for a flight to Ellington Field outside Johnson Space Center, Houston, Texas. The following day it flew to Dryden Flight Research Center at Edwards AFB, California, making the final stage to Los Angeles (using the call sign Astro 97) on September 21, arriving over the city accompanied by two F-18s. Endeavour is on display at the California Science Center."