It is commonly known that the lack of new propulsion technologies has held space exploration opportunities to a minimum. A particular frustration is the lack of very-high specific impulse, high thrust devices that do not exist and will not exist for the foreseeable future. In effect, spacecraft and humans are stuck in the gravity wells of Earth and the sun.

If we are to ever travel to other stars, dramatic propulsion advances will be required. Before advancing the needed engineering technologies to realize interstellar travel, we must first address the relevant physics, or natural laws, governing yet undiscovered propulsion phenomena. Once these discoveries are achieved, they can be applied to working devices.

While the discovery of new force-production and energy-exchange principles appears to be exciting, it clearly is very challenging and possibly very expensive. Nevertheless, if the human race is to survive, we must eventually depart earth and find new worlds to discover and populate.

Fortunately, we have a long time before our home planet is uninhabitable, probably millions of years. But, the quest for the needed propulsion technologies will take at least tens, if not hundreds, of years to achieve. Many paths will surely prove impractical or impossible. Successful research is never guaranteed, but failure to pursue such research offers a very negative guarantee.

Experienced researchers know that success can be elusive, even after many trials and experiments. Breakthroughs do not generally happen "overnight," but take a long and tedious path through a forest of uncertain paths. One conservative approach is to proceed in small, incremental steps that focus on immediate questions and lead to enhanced understanding of the problems.

Through such a process the researcher can achieve increased insight and understanding. Invariably, we must achieve a better perspective on the lingering unknowns of our universe, because the ability to travel between stars will require a much better understanding of the universal laws of physics.