Much earlier in my own lifetime America as a national government still had some quite noble dreams, including some that seemed wildly impractical. For a sad example, we had the War on Poverty that ultimately fell before the Biblical perspective of John 12:8: "You will always have the poor among you..." As a happy and successful example, we had the Apollo Program to reach the moon.
Along the lines of that success, I started thinking about a very large project near the limits of our capabilities--and arrived at terraforming Venus as something we could be be seriously thinking about, whether or not America is capable of taking the lead. It turns out that Wikipedia does have an article about terraforming Venus, but I guess that just shows that some people do agree with me about the essential feasibility of the idea. Not sure what will be in that article if you follow the link now versus when I read it, but I can offer a few obvious critiques and minor extensions:
- We'd need to start with a very intense robotic exploration of the current state of the planet to make sure there is no life there now, or even an imminent (as in the next billion years or so) potential for life. Obviously, that could not be life as we know it, but we obviously don't know much about the limits of the universe, so a proper study would itself be a major and long-term investment.
- I'd favor relatively small controllable mirrors in orbit around the planet. This would require a whole lot of computing power (mostly for the weather modeling), but relatively little physical power. Each mirror would essentially be a wire loop with a thin reflective film stretched across it, and a remotely controlled gyroscope at the center to reorient the mirror continuously as needed. In the case of Venus, most of the mirrors would be used to shade the planet most of the time, since there's a large surplus of solar energy at that distance from the Sun, but that energy could be directed to local power generating stations on the planet.
- The design goal of the power stations would be to minimize the heat and maximize the conveniently usable electricity.
- The power stations would then be used to power robotic factories. Their three most important tasks would be to produce more robotic factories, to generate hydrogen to boost more mirrors into orbit, and to produce really large chemical plants to change the atmosphere. Of course the real key is the self-replicating factory, since that geometric progression would be able to grow extremely rapidly once we get past the bootstrap phase.
- The idea of changing the Venusian day (in the Wikipedia article) seems to me to be a total boondoggle. If we have sufficiently sophisticated control over the orbital mirrors, we can simply use them to make day and night whenever we want them at any location on the planet. This would depend on very advanced weather modeling--but that's a technology we also need to develop for use right here on Earth.