Cheers!
They are Lockheed D-21 Mach 3 drones as picture earlier on a SR-71 and B-52.
From wiki -
A total of 38 D-21 and D-21B drones were built with 21 expended in launches. The remaining 17 were initially stored at Norton Air Force Base, California, then moved to Davis-Monthan Air Force Base “boneyard” near Tucson, Arizona,[24] in 1976 and 1977. With the base open to the public, the D-21 drones were quickly spotted and photographed. The Air Force called them GTD-21Bs with the GT standing for Ground Training.
One is also on display at the Evergreen Museum on OR.
