What is the value of that Helium 3?
“About 25 tonnes of He3 would power the United States for 1 year at our current rate of energy consumption. To put it in perspective: that’s about the weight of a fully loaded railroad box car, or a maximum Space Shuttle payload.
To assign an economic value, suppose we assume He3 would replace the fuels the United States currently buys to generate electricity. We still have all those power generating plants and distribution network, so we can’t use how much we pay for electricity. As a replacement for that fuel, that 25-tonne load of He3 would worth on the order of $75 billion today, or $3 billion per tonne.
The Payoff
A guess is the best we can do. Let’s suppose that by the time we’re slinging tanks of He3 off the moon, the world-wide demand is 100 tonnes of the stuff a year, and people are happy to pay $3 billion per tonne. That gives us gross revenues of $300 billion a year.
To put that number in perspective: Ignoring the cost of money and taxes and whatnot, that rate of income would launch a moon shot like our reference mission every day for the next 10,000 years. (At which point, we will have used up all the helium-3 on the moon and had better start thinking about something else.)”