Let us optimistically assume that sooner or later a workable interstellar propulsion system will be found, and also be built and successfully tested in space. While this would be a great advance toward making interstellar travel possible, it nevertheless does not automatically follow that a voyage to the stars will in fact be attempted. There are a few other issues that must also be settled first: for example, a habitable exoplanet must be identified. It must be suitable for human colonization and ought to be a reachable distance away from Earth within a reasonable period of travel time. Second, engineers must provide a plausible space vehicle design architecture, and a spacecraft of that design must then be constructed, and tested successfully. Such a craft does not exist as yet, one among many reasons being that the specifications for it depend in turn upon the size and makeup of the likely boarding population. But both of those factors are still unknown. In addition, and perhaps most important of all, an unprecedented level of funding and resources must be allocated to the project.