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A manhole cover launched into space with a nuclear test is the fastest human-made object. A scientist on Operation Plumbbob told us the unbelievable story. //
Robert Brownlee was on the Operation Plumbbob team that launched an object in space before Sputnik.
They put a manhole cover above a nuke underground, and the explosion shot the iron cap into space.
The fastest human-made object was part of the US government's nuclear testing in the 1950s.
But the very first underground nuclear tests were a bit of an experiment — nobody knew exactly what might happen.
The first one, nicknamed "Uncle," exploded beneath the Nevada Test Site on November 29, 1951.
Uncle was a code for "underground."
It was only buried 17 feet, but the top of the bomb's mushroom cloud exploded 11,500 feet into the sky. //
The underground nuclear tests we're interested in were nicknamed "Pascal," during Operation Plumbbob in 1957. //
Brownlee said he designed the Pascal-A test as the first that aimed to contain nuclear fallout. The bomb was placed at the bottom of a hollow column — 3 feet wide and 485 feet deep — with a 4-inch-thick iron cap on top.
The test was conducted on the night of July 26, 1957, so the explosion coming out of the column looked like a Roman candle. //
Brownlee wanted to measure how fast the iron cap flew off the column, so he designed a second experiment, Pascal-B, and got an incredible calculation. //
Brownlee replicated the first experiment, but the column in Pascal-B was deeper at 500 feet. They also recorded the experiment with a camera that shot one frame per millisecond.
On August 27, 1957, the "manhole cover" cap flew off the column with the force of the nuclear explosion. The iron cover was only partially visible in one frame, Brownlee said.
When he used this information to find out how fast the cap was going, Brownlee calculated it was traveling at five times the escape velocity of the Earth — or about 125,000 miles per hour. //
Pascal-B's estimated iron cover speed dwarfs the 36,373 mph that the New Horizons spacecraft — which many have called the fastest object launched by humankind — eventually reached while traveling toward Pluto. //
"After I was in the business and did my own missile launches," he told Insider in 2016, "I realized that that piece of iron didn't have time to burn all the way up [in the atmosphere]."
Mere months after the Pascal tests, October 4, 1957, the Soviet Union launched Sputnik, the world's first artificial satellite. While the USSR was the first to launch a satellite, Brownlee was probably the first to launch an object into space. ///
Now exceeded by the Parker Solar Probe...
