Was a manhole cover really launched into space?

In the short history of human space travel, officially, the first man-made object in space was the satellite Sputnik.

Launched by Russia on October 4, 1957, it was just 58cm wide, about the size of a beach ball. In escaping Earth, this little metal sphere kicked off the epic space race between Russia and the US, which would culminate with Neil Armstrong and Buzz Aldrin landing on the Moon.

But unofficially, legend has it that before Sputnik, something else was accidentally blasted into space.

A manhole cover.

Right now, it could still be soaring through the solar system, millions of miles from its humble beginnings plugging a hole in the ground.

Fortunately for Sputnik, in the almost 70 years since, scientists have been unable to say for certain whether or not the unbelievable feat happened.

Why was a manhole cover shot into space?

Between May and October 1957, a series of 29 nuclear tests, dubbed Operation Plumbbob, were conducted at a test site in Nevada, US.

However, as the summer progressed, nuclear scientists became concerned about the amount of radiation from tests carried out above ground. 

In July of that year, the team conducted an experiment code named Pascal A, led by nuclear weapons scientist Dr Robert Brownlee. For this experiment, the team drilled a borehole 500ft deep for what was to become the world’s first underground nuclear test.

However, the bomb was much more powerful than expected – around 50,000 times more powerful. 

In a blog post, Dr Brownlee wrote that Pascal A was the ‘world’s finest Roman candle, because at night it was all visible.’ 

‘Blue fire shot hundreds of feet in the air. Everybody was down in the area, and they all jumped in their cars and drove like crazy, not even counting who was there and who came out of the area.’ 

But the team was undeterred, and set up the experiment again, with a slight modification.

On August 27, in a test called Pascal B, the team placed a four-inch iron concrete cap that weighed at least half a ton over another 500ft-deep borehole, with the bomb installed below. The lid was then welded shut to seal in the equipment.

Dr Brownlee had calculated that force would be exerted on the cap, and knew that it would pop off from the pressure of the detonation, so the team installed a high-speed camera to see what happened to it. 

Dr Brownlee recalled: ‘In the event, the cap appeared above the hole in one frame only, so there was no direct velocity measurement.

‘A lower limit could be calculated by considering the time between frames [and I don’t remember what that was], but my summary of the situation was that when last seen, it was “going like a bat!!”.’

However, he later calculated the manhole cover to have been travelling around 125,000 miles an hour, about five times Earth’s escape velocity. If true, the manhole cover is one of the fastest human-made objects ever built.

Dr Brownlee added: ‘As usual, the facts never can catch up with the legend, so I am occasionally credited with launching a “manhole cover” into space, and I am also vilified for being so stupid as not to understand masses and aerodynamics, etc, etc, and border on being a criminal for making such a claim.’ 

So…is there really a manhole cover in space? 

Nuclear scientist Dr Tim Gregory tells Metro.co.uk that is not outlandish to believe that a manhole cover can be shot into space.

‘You can launch anything into space if you give it enough of a push!’ he says.

‘It’s difficult, though, because Earth is the biggest rock in the solar system.

‘There’s a lot of gravity to fight against on the way up. The Earth’s atmosphere adds another difficulty, because air resistance tries to drag objects to a standstill.’ 

But on the question of whether he believes a manhole cover is actually travelling through space at the moment, he says: ‘I’m on the fence – I could believe it either way.

‘It was definitely travelling fast enough to escape Earth’s gravity.

‘But on the other hand, it might have burned up on its way out of the atmosphere like a meteorite falling in reverse.

‘Speaking with my scientist hat on – or should I say lab coat? – I’d have to see physical proof before I made up my mind. I’ll keep an eye out next time I’m looking through my telescope at the stars!’ 

The 1992, the February/March issue of Air & Space magazine revisited the moment.

‘Dr Brownlee… knew the lid would be blown off, he didn’t know exactly how fast,’ it said.

‘High-speed cameras caught the giant manhole cover as it began its unscheduled flight into history.

‘Based upon his calculations and the evidence from the cameras, Brownlee estimated that the steel plate was travelling at a velocity six times that needed to escape Earth’s gravity when it soared into the flawless blue Nevada sky. 

‘”We never found it. It was gone,” Brownlee says, a touch of awe in his voice almost 35 years later.

‘The following October the Soviet Union launched Sputnik, billed as the first man-made object in Earth orbit. Dr Brownlee has never publicly challenged the Soviet’s claim. But he has his doubts.’

Sadly, like many legends, whether a manhole cover actually went to space cannot be confirmed as it was never seen again, either on Earth or out in space. It could have been vaporised. 

But as far as legends go, it is out of this world.