Science Fiction author Charlie Stross talks about “Shaping the Future” He wrote Accelerando and Singularity Sky among other books.
He notes how progress used to measured by top speed, but how that stopped between 1950-1970. I believe that speed will become a useful measure of progress again. I believe that we can and will burst through the roadblocks that have stalled progress to faster speed Lasers, magnets, nuclear fusion, new production (molecular nanotechnology) and new materials will help break things wide open. I believe that superior room temperature superconductors will be created. Which could be used to ground launch a magnetic sail
Charles Stross also mentions how the convergence of technology makes things less predictable. I believe that the convergence of our progress with lasers, magnets, materials and molecular nanotechnology will result in easy and cheap access to space and high acceleration up to significant fractions of light speed.
Energy will also be transformed. Mass produced and cleaner nuclear fission is possible in the form of molten salt thorium reactors, nuclear fusion (z-pinch version or Bussard fusion or another version), and massive solar space power.
The relative stability of the infrastructure and makeup of civilization for the past 30-60 years is about to change in a major way over the next 30-100 years. Unless we totally screw up the future we will defintely have a radically different scope and capability in 2050+. I think it can happen even sooner.