Ahhhh... the early '70s. A time when social constraints were crumbling and smoking cigarettes would only maybe kill you. Everything seemed immediately possible. Case in point being Mike Griffin, former NASA Administrator, on his plans for galaxy domination: "I know that humans will colonize the solar system and one day go beyond," he proclaimed at the time.
Fast forward half a century and Griffin's dream hasn't exactly been realised. Yet, thanks to him and many other Free Love-generation innovators at NASA's Ames Centre and Stanford University, we have some pretty epic paintings. Paintings so spectacularly hyperreal that they probably wouldn't even be fathomed today without CS5 and/or a hefty dose of Salvia.
Realised by Princeton physicist Gerard O'Neill and penned by a team of artist monkeys (not in a post-apocalyptic Planet of the Apes type of way, but this could be an appropriate analogy), the drawings depict giant orbiting spaceships for humans to live in. The resulting specs are essentially a real estate agent's dream: they're weightless, clean, and quiet facilities blessed with "the best views in the solar system".
Of course, even the best painters can only depict so much, so there's a few design holes that NASA may want to address if they ever build them for reals, i.e. fuel and water sources, waste facilities, and the precise amount paid by George Lucas to blatantly rip these off for Star Wars. Oh, and then there's that other question of precisely WHY human beings need to populate the skies. But let's just leave that for another day, kids.
Go back to the future at settlement.arc.nasa.gov