Sensawunda!
George Potter has had his childish sense of wonder reprimed by Karl Schroeder's idea for a Verne gun. Cool, indeed. Just get the socialist wastes of air out of power and free men & women will do this and a whole lot more.
Put 1.5 terawatts of clean solar power into orbit with less than ten launches. Obsolete coal and petroleum power production with green baseline power, using less than a 10th the number of solar cells as you'd have to install on Earth to capture the same amount of sunlight.
Orbit an entire space elevator with one launch. Set it up, retire the gun, and get on with a clean space age.
Do the same thing with an orbiting greenhouse infrastructure. Drop solar-powered mass drivers on the moon to feed a continual stream of building material to the building sites.
Orbit fuel depots to drop the price of conventional rocketry to orbit through the floor. One shot and access to space for NASA becomes 10 times cheaper.
Send up a telescope so big that it can image the continents of planets circling other stars.