Finding the resources to reach the planets will require refocusing on domestic politics and shifting the American political environment.

When my son and I flew to Florida to see Atlantis’ final flight, our airline tickets cost us about $6.50 per kilogram (excluding luggage). Sending the space shuttle’s cargo into low Earth orbit cost about $20,000 per kilogram. That huge difference is the major challenge facing spaceflight today. Unless we drastically reduce the cost of reaching orbit, the large-scale exploration and exploitation of space will not occur.