Fun Fact!
If we were to ask you what the fastest man made object that humans have ever launched was, what would you say? A jet? Or Maybe an Apollo era spacecraft or a SpaceX rocket? While all are great guesses, none are the right answer. The correct answer is a man hole cover, yes a man hole cover, that was launched following a nuclear bomb test in 1957.
In 1956, Dr. Robert Brownlee of Los Alamos National Laboratory was tasked with exploring the feasibility of conducting underground nuclear detonations. The first subterranean test, named Pascal A, involved lowering a nuclear device down a 500 ft (150 m) borehole. To everyone's surprise, the explosion yielded 50,000 times more energy than anticipated, resulting in a massive jet of fire shooting hundreds of feet into the air.
Following this, during the Pascal-B test in August 1957, scientists attempted to contain the nuclear blast by welding a 900-kilogram (2,000 lb) steel plate cap over the borehole, despite Brownlee's skepticism about its effectiveness. When Pascal-B was detonated, the blast shot straight up the test shaft, propelling the cap into the atmosphere at an astonishing speed of over 66 km/s (41 mi/s; 240,000 km/h; 150,000 mph). Strangely, the plate was never recovered. Scientists theorize that the intense compression heating caused the cap to vaporize as it streaked through the atmosphere.
To capture this incredible event, a high-speed camera, taking one frame per millisecond, was trained on the borehole. Surprisingly, the plate only appeared in a single frame, but this was sufficient to estimate its speed. Dr. Brownlee humorously described the cap's velocity as being "going like a bat!" Based on his calculations, the explosion, coupled with the unique design of the shaft, could have accelerated the plate to nearly six times Earth's escape velocity.
In 2015, Dr. Brownlee stated he had no definite explanation for the cap's fate but speculated that it likely vaporized before entering space. Subsequent calculations in 2019 strongly support the theory of vaporization, although this result remains unconfirmed.
