[Solamente]

(Full Article) http://www.asi.org/adb/02/09/he3-intro.html

The supply

Some He3 is available on Earth. It is a by-product of the maintenance of nuclear weapons, which would supply us with about 300 kg of He3 and could continue to produce about 15 kg per year. The total supply in the U.S. strategic reserves of helium is about 29 kg, and another 187 kg is mixed up with the natural gas we have stored; these sources are not renewable at any significant rate.

In their 1988 paper, Kulcinski, et al. (see ref note below), estimate a total of 1,100,000 metric tonnes of He3 have been deposited by the solar wind in the lunar regolith. Since the regolith has been stirred up by collisions with meteorites, we'll probably find He3 down to depths of several meters.

The highest concentrations are in the lunar maria; about half the He3 is deposited in the 20% of the lunar surface covered by the maria.

To extract He3 from the lunar soil, we heat the dust to about 600 degrees C.

We get most of the other volatiles out at the same time, so we'll be heating up the rocks anyway. (To get the oxgyen out, we'll turn up the furnace to about 900 deg C and do some other nasty stuff; but that's a different story.)
The Energy

That 1 million metric tonnes of He3, reacted with deuterium, would generate about 20,000 terrawatt-years of thermal energy. The units alone are awesome: a terrawatt-year is one trillion (10 to 12th power) watt-years. To put this into perspective, one 100-watt light bulb will use 100 watt-years of energy in one year.

That's about 10 times the energy we could get from mining all the fossil fuels on Earth, without the smog and acid rain. If we torched all our uranium in liquid metal fast breeder reactors, we could generate about half this much energy, and have some interesting times storing the waste.
The Value

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.)

[SoFarRight]

Thanks for the freepmail link, I'll check it out later.

SFR

[Centurion2000]

bump

[Cincinatus' Wife]

Mining and Manufacturing on the Moon

The main purpose of returning to the Moon is to prove we can use it's resources to live off-planet. The realization that we can will forever change space exploration. We will no longer be tied to Earth.

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Bush's charge to his space commission:

Scope and Objectives: The mission of the Commission shall be to provide recommendations to the President on implementation of the vision outlined in the President's policy statement entitled "A Renewed Spirit of Discovery" and the President's Budget Submission for Fiscal Year 2005 (collectively, "Policy"). The Commission shall examine and make recommendations to the President regarding:

a. A science research agenda to be conducted on the Moon and other destinations as well as human and robotic science activities that advance our capacity to achieve the Policy;

b. The exploration of technologies, demonstrations, and strategies, including the use of lunar and other in situ natural resources, that could be used for sustainable human and robotic exploration;

c. Criteria that could be used to select future destinations for human exploration; Long-term organization options for managing implementation of space exploration activities;

d. The most appropriate and effective roles for potential private sector and international participants in implementing the Policy; and

e. Methods for optimizing space exploration activities to encourage the interests of America’s youth in studying and pursuing careers in mathematics, science, and engineering; and Management of the implementation of the Policy within available resources.