Problem Of Mining (On The Moon)

Our moon is our nearest celestial neighbour. And over the course of several million years it has been our best friend; albeit a faraway one--without Luna to shield us from asteroids and other celestial rocks, we would have been hit more frequently.

Image: nineplanets.org

That being said, the process of asteroids landing on the moon has made Luna a prosaic mix of a plethora of materials--silicon, iron, calcium, aluminium, potassium, and phosphorus. Ah, not forgetting the elusive Helium-3. Helium-3 is an isotope of the conventional Helium-4.
It is produced by the sun, and together with other charged particles they stream towards Earth all the time. But the Earth's magnetic field is strong enough to deflect most of the charged particles, and hence most of them end up on the moon, where the magnetic field is far weaker than Earth's.

Image: physicsforums.com

Helium-3 can be used in fusion reactors to generate electricity. It is non-radioactive (a plus point for radiophobic), the proton generated can interact with the electromagnetic field and this will result in a more efficient electricity generation. It is also cleaner, and produces less neutron flux than the conventional fusion reaction.

Image: crisisboom.com

Given all these, why haven't NASA go up to the moon and start mining?

First of all, the concentration of Helium-3 on the moon is somewhat disappointing. Soil samples taken from the moon revealed that the concentration of Helium-3 is only 0.000003%, i.e in a kilogram of soil, we can only get around 3 milligrams of Helium-3. Tenaga Nasional Berhad (TNB) generated a total of 108539 Gigawatt-hour of electricity in 2007. To generate that amount of energy, we would require at least 660.48 kg (conversion rate of 493 megawatt-hours per 3 grams of Helium-3) of Helium-3. To acquire that amount of Helium-3 from the moon, we will have to dig up at least 220160 tonnes of moon soil.

Image: spaceports.blogspot.com

Now that's a lot of digging. But we have not calculated the cost of shipping it back to Earth, and the cost of sending huge mining machines to the moon. Even if we utilize the cheapest available alternative, the Russian-made Proton rocket (to all Malaysian out there, this is such an unfortunate coincidence huh?), it would still cost a hefty $4300 to launch a kilogram of material not to the moon, but only to the low Earth orbit. And mind you, the calculation above only applies to Malaysia, a small country with GDP US$ 247.78 billion (2010 est.), and we have yet to include energy-hungry krakens like China and the United States.

I don't know about you, but I'll stick to the conventional fission energy.

Malcolm
info:
http://en.wikipedia.org/wiki/Helium-3#Fusion_reactions
http://en.wikipedia.org/wiki/Space_elevator_economics#Costs_of_current_systems_.28rockets.29
http://www.gfmag.com/gdp-data-country-reports/226-malaysia-gdp-country-report.html#axzz1grCc6cct