Operation Plumbob, United States. During the Pascal-B nuclear test of the Plumbob test series, a 1,000-ton underground test, images from high-speed cameras show a 2,000-ton manhole cover being shot upward at a speed of at least 66 km/s (only one frame shows it in flight). It is likely the fastest human-made object (faster than the Voyager probes). Although its speed is greater than the escape velocity of the Solar System, the manhole cover likely never left Earth’s atmosphere, having been pulverized by air friction.
