The first A-12, known as Article 121, was built and ground tested in Burbank during January and February 1962. Because the aircraft was too secret to fly to the test site and too large to carry on a cargo plane, it had to be trucked. 

The only A-12 trainer (927) was a two seater version intended for pilot training. The A-12B trainer was known as The Titanium Goose.

SR-71A 17960 made her final flight on February 27, 1990, into Castle Air Force Base, California. She roared over the runway at low level for one last high speed pass before touching down for the last time.

LASRE was NASA's Linear Aerospike SR-71 Experiment which took place at the Dryden Flight Research Center at Edwards Air Force Base, California, until November 1998. The experiment sought to provide flight data to help Lockheed Martin validate and tune the computational predictive tools used to determine the aerodynamic performance of the Lockheed Martin X-33 lifting body and linear aerospike engine combination and to lay groundwork for a future reusable launch vehicle.