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.