I believe that we will eventually figure it out, but I don't think we are even close to that scientifically. I think the first part would be to build the craft in orbit instead of on the ground. A lofty proposition, but if we can avoid escaping the atmosphere the ship can be built for space, instead of built for space AND for escaping an atmosphere.

The idea does offer problems of its own don't get me wrong, but I think it would make the most sense. And then of course we need a better propulsion system, I just don't think liquid fuel will do. Hopefully some nuclear engine or maybe we'll have learned how to manipulate gravity or move through a different dimension or something even more insane than we could have ever thought. I don't think it'll be this generation or the next, I think it'll be hundreds or even a thousand or who knows how long. We could go extinct and the next dominant lifeform could figure out a way. Who knows though. I sure don't lol