This U-2C carries USAF serial 56-6681, was former N801X with the CIA and was delivered to the NASA on 5 March 1966. It returned to the USAF but returned again to NASA on 3 June 1971. It was used in the 'Earth Servey 4' program, redesignated to WU-2C and operted from Ames up to June 1987. It was preserved at Ames Moffet Field from mid 1989.

Used test reg N801X before delivery to the USAF as U-2A 56-6681. Converted to a U-2G in 1964 then converted to a U-2C and to NASA Ames Research Center, NAS Moffett Field, CA, as NASA 708 in 1971. Retired in 1976 and preserved there.

Originally built as U-2A 56-6681 and later converted to a WU-2A. Modified as a U-2G capable of operating off US Navy aircraft carriers. Transferred to NASA and remodified back to U-2C version. NASA operated this a/c from 1971 through 1987 out of the Ames Research Center at Moffett Field. It is now on display there.