洛克希德D-21无人机 - 照片和视频

这 洛克希德D-21 was an American reconnaissance drone with maximum speed in excess of Mach 3.3 (2,215 mph; 3,564 km/h). The D-21 was initially designed to be launched from the back of a M-21 carrier aircraft, a variant of the Lockheed A-12 aircraft. Development began in October 1962. Originally known by the Lockheed designation Q-12, the drone was intended for reconnaissance deep in enemy airspace. The D-21 was designed to carry a single high-resolution photographic camera over a preprogrammed path, then release the camera module into the air for retrieval, after which the drone would self-destruct. Following a fatal accident when launched from an M-21, the D-21 was modified to be launched from a Boeing B-52 Stratofortress. Several test flights were made, followed by four unsuccessful operational D-21 flights over the People’s Republic of China, and the program was canceled in 1971.

源： 洛克希德D-21无人机维基百科

洛克希德D-21无人机是一种超音速侦察机，旨在飞越敌方领土并收集情报数据。该无人机是从改装的A-12或B-52飞机上发射的，速度可达3.3马赫。无人机携带一台相机，该相机将其胶片喷射到海洋上的胶囊中，在那里将由C-130飞机回收。D-21计划始于1960年代初，作为对U-2事件的回应，当时一架间谍飞机在苏联上空被击落。该计划在四次作战任务后于1971年被取消，但没有一次成功。D-21无人机是当时最先进和最秘密的项目之一，但也是最昂贵和最危险的项目之一。