I think we could almost do Venus and Mars now with the right funding and push. The intersteller concepts are heating up as well and they are conceptually talking about placing lasers in the high desert in Chile that would focus on little mini space craft that we would then push at a considerable percentage of the speed of light to other star systems. It will still take decades and one of the main issues is the power requirements to transmit back to earth the findings. We will eventually figure it out. Unless we blow ourselves up first which is possible.