SR-71 Blackbird was a long-range, Mach 3+ strategic reconnaissance aircraft
Modified A-12 (M-21), a two-seat variant of SR-71, carried and launched the Lockheed D-21, an unmanned, faster and higher-flying reconnaissance drone. The M-21 had a pylon on its back for mounting the drone and a second cockpit for a Launch Control Operator/Officer (LCO). The D-21 was autonomous; after launch, it would fly over the target, travel to a predetermined rendezvous point, eject its data package, and self-destruct. AC-130 Hercules would catch the package in midair.
The M-21 program was canceled in 1966 after a drone collided with the mother ship at launch.