When it comes to space, there is an issue with our human desire to see and experience everything. A significant issue. The issue, after all, is space. It is much too big. Even at the highest speed permitted by the Universe, it would take years for us to reach our closest neighboring star.
However, another human motivation is to overcome challenges. And that is just what NASA engineer David Burns has been up to in his own time. He has developed a concept for an engine that, he claims, could accelerate to 99 percent the speed of light – all without the need for fuel.
He’s uploaded it to NASA’s Technical Reports Server under the title “Helical Engine,” and on paper, it works by taking advantage of the way mass changes at relativistic speeds – those near to the speed of light in a vacuum.
Understandably, this paper has generated hype on a par with the early days of the EM Drive. And certainly, there have been headlines asserting that the engine may ‘violate the laws of physics.’
However, although this thought is intriguing, it is unlikely to breach the laws of physics anytime soon.
Burns presents a box with a weight inside, threaded on a line, and with a spring at either end bouncing the weight back and forth as a thought experiment to illustrate his notion. In a vacuum – such as space – this has the illusion of wriggling the whole box, while the weight seems to remain still, much like a gif stabilized around the weight.
The box would remain in the same position overall – but if the mass of the weight increased in just one direction, it would cause a stronger push in that direction, and therefore thrust.
This should not be entirely conceivable according to the concept of conservation of momentum, which states that a system’s momentum stays constant in the absence of external influences.
But! There is a loophole in special relativity. Special relativity states that things acquire mass as they approach the speed of light. Thus, if the weight is replaced by ions and the box is replaced by a loop, the ions may potentially move quicker at one end of the loop and slower at the other.
However, Burns’ drive is not a closed loop. It is helical, similar to a stretched spring – thus the name “helical engine.”
“The engine accelerates ions confined in a loop to moderate relativistic speeds, and then varies their velocity to make slight changes to their mass. The engine then moves ions back and forth along the direction of travel to produce thrust,” he wrote in his abstract.
“The engine has no moving parts other than ions travelling in a vacuum line, trapped inside electric and magnetic fields.”
It sounds rather clever, doesn’t it? And it is – theoretically. However, it is not without considerable practical difficulties.
The helical chamber, according to New Scientist, would have to be rather huge. To be accurate, it is around 200 metres (656 feet) long and 12 metres (40 feet) in diameter.
However, what about in the vacuum of space? It could possibly work. “The engine itself would be able to get to 99 per cent the speed of light if you had enough time and power,” Burns told New Scientist.
So the bottom line is that Burns’s idea is intriguing and very clever but it needs to work in real life and for that, we will have to wait as there are lots experimentations required before we get to the final space ship plans.
Reference(s): New Scientist , NASA