The Adjacent Possible Of Thruster Technology

A few days ago, I had a few extra minutes before one of my classes, so, like most people in our generation, I went on my phone and opened  TikTok.  While browsing my For You Page, I came across this video, which talked about a new type of engine, the helical or speed-light engine, which is capable of almost reaching the speed of light and is currently being studied by SpaceX. Although the animation was a little strange and the creator seemed to like Elon a little too much, the video still sparked my interest and I had to look into it further.

Well, I don’t work at SpaceX, so I can’t tell you what they’re currently working on. However, after looking into the topic, I found out that the helical engine is a hypothetical idea created by NASA scientist David Burns. The concept behind the engine is that it creates thrust(forward momentum) by bouncing particles back-and-forth within a chamber. As particles approach the speed of light, their mass increases, and decreases as it slows down. Thus, the engine would increase the speed of the particles as they move towards the front of the thruster, increasing their mass, and decrease their speed as the particles move toward the back of the thruster, decreasing their mass. This difference in mass would cause the rocket to be pushed forward more than backward, causing a net forward momentum. Sadly, this idea suffers a similar fate as the Analytical Engine, where the idea is too abstract for its time. The amount of thrust that is produced is insanely small, thus a rocket would need a an engine that is unreasonably large in order to produce the needed amount of thrust. In order for this thruster to work, we would need a way to better concentrate the particles and create a greater difference within their speeds to generate thrust, which could take decades to develop. This is without mentioning the fact that the engine would also be breaking the law of Conservation of Momentum, thus making it impossible to create. Breaking the laws of physics may not be a complete roadblock, though, as we have had to modify our understanding of physics before(take quantum mechanics, for example). The laws of physics could apply differently as an object reaches such high speeds. However, the research needed to study this possibility would again take many years and would most likely require technology that we do not currently possess.

So, after realizing that this technology was too advanced for development, I decided to look into some other, more practical engines, and I came across the electric plasma jet engine. This engine pushes microwaves and ionized air through separate tubes, where they intersect at a narrow point, causing a plasma of immense heat and pressure. This engine has also already been tested and shows promise, but again it falls into the same problem: it is extremely inefficient. The amount of force released by the thruster is nowhere near enough to launch a rocket. The heat released is also too intense to contain, and a harmful amount of radiation is released by the engine. Before application, many other developments in material science and plasma technology need to occur so that an efficient amount of thrust can be created in a safe and reliable manner.

After looking into this technology, I couldn’t help but think about what Steven Johnson said about the Adjacent Possible, as it fits perfectly into this technology. The engineers at NASA and other space programs want to push the limits of scientific discovery, so in their minds, they feel that they need to design revolutionary pieces of technology that could push the limits of space travel. However, this revolutionary technology is not revolutionary if it can’t be built and the rationale behind the ideas are improbable or even impossible. In order to make the desired improvements in the technology, the scientists and engineers need to slow down and work on improving the engines one component at a time. Rather than trying to skip multiple rooms, they need to walk through each door with careful consideration and meaningful decision. That is how they are going to built the future of thruster technology that will allow us to reach new speeds never before thought possible.

I tried simplifying the concept of the helical engine the best I could to make this post easier to read, so if you are confused(or interested in learning more), I found this video and this video to be very helpful(the second video has some Calculus 3 concepts in there, so it may be hard to follow depending on your math background). This is the original NASA paper released by David Burns, if you’re interested in reading that, too.

For the electric plasma jet engines, I used this video, which I would definitely recommend. Of all the videos, I found this one the most interesting, and it is very easy to follow.