The reason we need breakthrough propulsion physics is that with it we can do everything that can be achieved with conventional propulsion much faster, more efficiently, and far cheaper over a fraction of a human lifespan.
So, while it is theoretically possible for a chemical rocket to reach Proxima Century, it would take a National Funded Effort in the Billions to Trillions and a few thousand years to reach Proxima Century with Chemical propulsion.
Fission and Fusion can decrease the time of travel, but not the cost and massive engineering complexity that those technologies would have to overcome to shorten the mission to less than 100 years. So, neither would make interplanetary travel practical within a fraction of a human lifespan.
With concepts like SFE propulsion, a breakthrough propulsion alternative would far exceed the current capability of any Newtonian propulsion system. If non-Newtonian propulsion is not possible then making Humanity a multi-planetary society is going to be next to impossible. So that’s the downstream benefits. Now, let’s talk about the immediate short-term or first-use benefits.
So, SFE devices can be placed in the category of non-Newtonian all Electric Field Propulsion Devices.
Field Propulsion in this case is a broad catch me all category that presupposes that the device can simply convert energy directly into motion via an energy exchange from the Electromagnetic Field of a device and a property of the surrounding space. Critics would point to there being no conclusive evidence that this is even possible, but it’s the same critics that are too afraid to explore the possibility of such a mechanism being allowed by the Universe. For this reason, there is zero dedicated funding for such research. If we don’t look, we will never find it. We have to assume that something is possible to justify its search. It’s pretty easy logic to understand.
So, what are the immediate market uses for a Propellantless Field Propulsion system? The short answer is that you can do everything that chemical and conventional propulsion technology can do, but way better. You can also do things that no chemical or conventional propulsion technology can do, like not run out of fuel.
So, the benefits are clear and the risk is extremely low.