The money quote:
PD: So today, one of my companies, Space Adventures, sends people into orbit privately. A trip is $40 million. Our next customer goes up in 5 days, Guy Laliberté, the founder of Cirque du Soleil.
If you were to calculate the energy requirement to put you and your space suit into orbit, you can actually calculate the amount of energy, it’s easy to do, it’s a high school physics problem, it’s mass times gravity times height to get the potential energy of the altitude, and then one half mass times velocity squared to get kinetic energy. It’s about 1.6 gigajoules. If you were to buy that over the electric grid at 7 cents a kilowatt hour, and you had an electric winch that could winch you up into space very easily, and you spend the energy over the course of an hour, it turns out that the cost to get you and your space suit into orbit, if you can convert the energy 100% efficiently, is about $100. So the price improvement curve from the cost of going to space today, which is $40 million, to theoretically what it could be in the future, which is $100, is extraordinary. So that’s the future that I’m focused on creating.
Given molecular manufacturing, that (energy) limit can be approached, and using the same kind of advances in technology and construction, the price of the energy could likely be brought down pretty drastically as well.