Forty years ago today, three American men—Neil Armstrong, Edwin "Buzz" Aldrin, and Michael Collins—were floating in a tiny spacecraft above the surface of the Moon getting ready for two of them to make history: tomorrow will be the 40th anniversary of the Apollo 11 moon landing.
If Neil, Buzz, and Mike could have looked ahead 40 years from that point, where would they have thought we'd be right now? The reality is that we haven't been back to the moon in decades, and our space program has languished by trying to do too much (space shuttles, space stations, earth science, planetary science, astronomy, robotic exploration, etc.) with too little funding. And here we are, finally talking about going back to the moon. But we're going to be doing so with basically the same level of technology that those three brave explorers had at their disposal.
That's not to say that we haven't learned anything in that time. We know far, far more about the effects of weightlessness on the body, about how the radiation of space will affect the next wave of explorers we send beyond low Earth orbit (LEO), and the avionics that control the spacecraft will be vastly more advanced than the mostly analog and mechanical components that powered Apollo 11 and the Eagle landing craft to the Moon.
But we have numerous challenges to overcome before routine flights to space stations and beyond are within the grasp of mere mortals like you and me: the cost of just getting to LEO are unimaginably high (they say that once you've gotten to LEO, you're halfway to anywhere in the Solar System); we still don't have a good way to protect the intrepid explorers aboard the space craft in the event of a solar radiation storm; we still don't have the ability to survive once we get where we're going without sending replacement supplied from Earth at great expense.
Decades before the U.S. space program was even conceived, science fiction writers painted a picture of a future with flying cars, asteroid mining, people travelling the stars in highly advanced spacecraft, extrasolar colonies, and more. And for the most part, they thought we'd be there by now. What went wrong?