We can be there tomorrow!
:)
Maybe we can. The most presently popular versions of physics indicate that there are 9 or 11 dimensions (if I remember correctly), of which we are only able to sense 3, or 4 if you count time.
It doesn’t seem wildly implausible to me that a more complete understanding of the actual, as opposed to perceived, universe might allow us to take a shortcut through some of these other dimensions that would take less or perhaps no time.
Insofar as a propulsion mechanism, of the four “forces” in the universe, we have good deal of control over the electromagnetic force. Even a little control over the gravitational force obviously creates the potential for far more efficient propulsion mechanisms.