One kg. 3he fused with 0.66 kg D yields 19 MW years of energy. This is 166,440,000 kilowatt hours…at $0.01 a kW hr. , about the same fuel cost as coal or uranium, this stuff is worth $1.6 million a kg.
One kg. 3he fused with 0.66 kg D yields 19 MW years of energy. This is 166,440,000 kilowatt hours…at $0.01 a kW hr. , about the same fuel cost as coal or uranium, this stuff is worth $1.6 million a kg.
If a solar power satellite amasses 100,000 tons, about 50,000 tons would be the steel frame and the rest would be magnesium reflectors with a thin coat of aluminum and turbogenerators, microwave generators and transmission antenna.
To get 50,000 tons of 0.5% steel we need 250 tons of carbon. One thousand he3 miners like the Mark 3 could produce 82,000 tons of carbon per year. That’s enough for 328 SPS, so in about three years of mining enough carbon would be produced for 1000 steel SPS. It will probably take over 50 years to build 1000 SPSs, so plenty of carbon could be produced on the Moon during their construction.
Also, 33,000 kg/yr of helium 3 worth about $50 billion per year would be produced concurrently.
I don’t think aluminum will be the chief material for SPS because of the difficulty of extracting it in terms of energy and the need for chemicals like sulfuric acid and chlorine as well as complex processing equipment. For steel we only need magnetic iron fines miners and magma electrolysis as well as carburizing and fluxing furnaces made of cast basalt or “fused adobe” and the energy required to make steel is not likely to be as great as the energy required to produce aluminum. Also, there is not enough copper on the Moon and no lithium to speak of to alloy aluminum so lunar aluminum will not be very strong. Wrought iron (less than 0.2% carbon) is stronger than unalloyed aluminum.
So helium 3 and volatiles mining would seem to come before SPS. See: http://www.moonminer.com/Reality-Check.html