The last time I watched the movie Spirit of St Louis, about Charles Lindbergh's 1927 flight across the Atlantic, I wondered what he would have done if someone had told him: "hey wait, in a few years you'll be able to do this in a few hours while drinking champagne and watching this movie. That's not how the human ego operates however. We take huge risks to be the first. Risks that would be far, far smaller if we waited a while for technology to catch up.
Of course if it weren't for the Cold War we might never have gone to the moon or built a space station or have our hopes for a verdant Mars dashed in the 1960's and 70's. Sometimes you are better off taking the risk, spending the money; but is that an argument for not moving on with the times?
While the press and much of the public is lamenting the end of the seriously flawed shuttle program, the real science of space exploration is continuing to produce astounding advances that dwarf the advancements to knowledge produced by our manned program. With the rapid advance of semi-autonomous robotics and miniaturization, it's foreseeable that the huge risk and titanic expense of sending people around the solar system and returning them alive and sane may be less and less worthwhile.
What have we learned from the shuttle experience? That space travel is still very risky, still vastly more expensive and difficult than we imagine when we design these things. Expensive enough that we will always make serious compromises in design that eventually make things even more expensive when we have to work around them. The shuttle is a textbook lesson in the perils of design by committee and politicians. It's catastrophes result directly from design decisions driven by economy.
If we are to continue the Space Station project for a while, perhaps there will be sufficient motivation to develop a smaller, lighter, truly reusable, economically sound and more modern supply vehicle, but the Space Station, if it has any justification, is all about practice in sending people to places to do what robots will probably be able to do much better before we get there.
Yes, perhaps we'll be able to support some sort of human existence on Mars for a period of time and perhaps construct a moon base that could, for a time, house humans, but it wouldn't be much of a life and it certainly shouldn't be called a "colony" in the way European settlements in the Americas were colonies. We still lack the money and the technology as well as a reason to develop them. In that respect science fiction tends to be a somewhat cloudy fun-house mirror of the past more than a window into the future.
Would we ever send; would we ever expend the huge resources to send men and women to Vesta, or Ceres much less to the vicinity of the outer planets with their monstrous radiation belts and no resources -- a journey that would force the new Conquistadors to live in conditions we now reserve for pickled herring -- and keep them in constant danger and deprivation for years? No, but we can send and have sent patient, unemotional and replaceable robots whose capabilities are expanding as fast as the universe itself. Would we spend trillions and ask a crew to take a decades long trip in a stinking tin can without a shower, drinking recycled urine and eating horrible food just to orbit Pluto? Will we ever travel to the nearest star? I doubt it, but the technology to send an unmanned vehicle is at least a real possibility, even if we won't live to see the pictures.
Robots can be sent in small vehicles; can be small vehicles, powered by small efficient ion motors and won't suffer from emotional problems or long for the cool, green hills of home. A cheap cell phone now has more computing power than existed anywhere when we first walked on the moon and high resolution video cameras are smaller than the human eye. (remember when color TV cameras were the size and weight of refrigerators and required a two man crew?) The rate of change is accelerating. Think of what we'll be able to do in the 20 or 30 years it would take to build manned rockets and ancillary equipment for a very risky Mars mission.
The shuttle was a 1970's design loaded with so much design compromise that it was obsolete before it got off the ground. Robotic missions on the other hand can go from the drawing board to landing on Jovian moons in fairly short order. The real science is done on places that would incinerate, irradiate, freeze and squash an astronaut, even if he survived the mind numbing confinement and squalor needed to get there and back.
Not so with the Dawn mission, now as of yesterday in orbit around the asteroid Vesta; an object so small and distant that even the Hubble telescope can't see anything but a featureless smear. Expect a flood of hi-res images in the next few weeks. In time it will move on to Dwarf Planet Ceres and surely gain some insight into the formation of planetary systems. That may be less a thing of dreams than small boys and Sci-Fi fans like to imagine but much more of a thing of science. We've already seen the sunset on Mars and watched dust devils cross the endless desert. We've heard the wind blow on Titan and seen its methane rivers and lakes and there's more to come as the technology improves.
It's impossible to do more than guess, but I'm guessing that long before we discover bug-eyed monsters on alien worlds, we'll be building our own in Pasadena and sending them there. You and I can see the dawn rise on worlds more alien than we can imagine and we can do it poolside with a glass of lemonade.