NASA engineer proposes fuelless engine to propel spacecraft

David Burns , an engineer based at NASA’s Marshall Space Flight Centre in Alabama, has unveiled what he calls a ‘helical engine’.
The ambitious device violates a basic law of physics - that for every action, there’s a reaction - but this hasn’t put Burns off the idea.
Speaking to New Scientist , he said: “I'm comfortable with throwing it out there.
"If someone says it doesn't work, I'll be the first to say it was worth a shot.”
In its most basic form, the helical engine features a ring inside a box that’s sprung in one direction, with the box recoiling in the opposite direction.
When the ring reaches the end of the box, it bounces backwards, and the box’s recoil direction switches too.
While this would usually result in the box wiggling back and forth, if the box and ring were travelling at the speed of light, as the ring approaches the front end of the box it would increase in mass because it’s going faster than when it was going backwards.
In practice, the helical engine would use a particle accelerator and ion particles, but the basic principal is the same.
In his study, published in in NASA Technical Reports Server , Burns explained: “Chemical, nuclear and electric propulsion systems produce thrust by accelerating and expelling propellants.
“Deep space travel is often a trade-off between thrust and large propellant storage tanks that eventually limit performance.
"The objective of this paper is to introduce and examine a unique engine that uses a closed-cycle propellant.”
Burns’ calculations predict that the helical engine could produce a forwards thrust up to 99 per cent the speed of light without breaking Einstein’s Theory of Relativity.
However, as it stands, the engine would need to be 200 metres long and 12 metres wide to work, meaning it’s not exactly practical for space travel.
Despite this, he still believes that his research could one day lead to a viable engine.
He added: “You have to be prepared to be embarrassed. It is very difficult to invent something that is new under the sun and actually works."



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