We still use chemical propulsion almost everywhere from cars to rocket engines, a breakthrough in propulsion systems will not only make solar system exploration feasible but will be greatly beneficial to our society by reducing pollution and costs.

We need the next steam engine for a new industrial revolution, space exploration and our society depends on it.

I think that all space resources should be channeled into this, our current approach to solar system exploration is the same as trying to explore the world by foot, expensive an inefficient and no matter how big our ambitions are we don't have the technology to accomplish them.