01/30/2007. Remarks by Jack McKillop: "This aircraft was built as a Model 377-10-26 Stratocruiser. It was rolled off the assembly line on July 22, 1949, made its first flight on August 20th and was delivered to Pan American Airways on September 29, 1949 registered N1038V and named 'Clipper Constitution' (later 'Clipper Hotspur'). The aircraft was withdrawn from service and stored at LaGuardia Airport, New York, New York, USA and returned to Boeing on August 4, 1960.

It was sold to Aero Spacelines and converted to the 'Super Guppy' configuration using parts from the YC-97J and two 377 Stratocruisers and made its first flight from Van Nuys Airport, California, on August 31, 1965. During a test dive on September 25, 1965, the aircraft was damaged when a large section of the upper fuselage collapsed but an emergency landing was made at Edwards AFB, Muroc, California.

In 1990, after many years with Aero Spacelines, it was sold to the National Aeronautics & Space Administration (NASA) and re-registered N940NA. It was later registered N940NS and in 1995, it was presented to the Pima Air & Space Museum in Tucson, Arizona, for preservation."