I believe the problem is that with current technology it isn't realistic to expect to accelerate continuously to a fraction of light speed where time dilation w

I believe the problem is that with current technology it isn't realistic to expect to accelerate continuously to a fraction of light speed where time dilation will be noticeable. We lack the ability to get a large enough amount of fuel off the planet and we obviously can't decelerate to harvest more fuel on the way there because then we lose the benefits of the continuous acceleration. EDIT: I wonder how feasible it would be to gather a large enough store of fuel from asteroids or comets before even beginning acceleration. You'd likely have to do it both ways which may make it a one-way trip if the destination doesn't have the necessary resources. The only way I'm aware of that we could power a long-running acceleration is via a nuclear-powered ion drive. But I don't believe the acceleration is great enough to make a dent in approaching the fraction of the speed of light we need for such a journey in a human lifetime. Please someone correct me if I'm wrong. I'd love to be wrong.