It's difficult to know where to start. Perhaps with the misguided notion that our primitive ape species should, or even could, become "an interplanetary species." Too much Star Trek watched as a child clearly has deleterious effects. Or perhaps with the notion of the skyhook, which would require developments in material science so far beyond our present capabilities as to live in the realm of magic? Or perhaps with the cost of such an endeavor, which would be hundreds of billions of dollars up-front with zero guarantee of success. Given the very real and very immediate challenges we face here on the only planet for which we're actually adapted, perhaps attempting to reduce the impact of persistent human stupidity would be a better use of time than fantasizing about pointless tech toys that would serve no useful real-world function whatsoever.