In the 1960's, they would have thought we would be living on Pluto by now and would have expected us to be on Mars by 1980.
They might well have been right about Mars too, if not for the anti-progress think-of-the-children movement that has effectively stalled nuclear development throughout the west.
Even sustainable base-load fusion might have been a reality today if we'd just had the will to keep the project funded. Yet it will never be properly funded because we'd obviously prefer to fight over fossil fuels (for all our lip-service to environmentalism). And for what reason? Because nuclear.