The problem with D/T fusion is that neutron emissions will gradually create radioactive waste from the reactor walls. This will only become an issue during decommissioning. So we’ll only seriously consider developing He-3 fusion when we’re decommissioning a bunch of 30 year old D/T fusion plants and the waste becomes a political burden. And even then, lunar He-3 mining won’t be on the table because He-3 is a waste product from D/T fusion. So you’ll have all the remaining D/T plants producing fuel for the first few generations of He-3 reactors.

Moreso, the technology that allows He-3 fusion, such as higher containment pressures, will also make D/T fusion more compact, opening up more uses (such as transport) even as He-3 takes over the bulk power markets.

Talking about He-3 as viable future lunar mining product makes you (and any space advocate) sound silly. It’s so far into the future we don’t know what circumstances will affect it. Will we have space elevators (making it cheaper to dump D/T reactor-wall waste on the moon than to mine He-3 from the moon) or will nanotech solar-paint and super-batteries make fusion irrelevant on Earth anyway? We can’t begin to guess.

Water. Then oxygen. Then bulk shielding. Then iron for simple bulk structures. Then platinum group metals for industry. And if we ever get to that stage, industry on the moon should be able to justify itself without further advocacy from us.

James,
Re: Defacing the moon.
You have a slight scale problem. Have a look at the shots of Earth taken by Apollo astronauts circling the moon. Look for the roads and mines. The cities and dams and so on. Can’t find any? Human activity vanishes at a that distance, except at night.

The moon will be even harder to visibly deface. You know how people walk around open cut mines and call it a “moonscape”… the moon is the slag spat out by a collision early in Earth’s history, the moon’s surface has been bombarded by asteroids for billions of years, and is blackened by unfiltered sunlight and radiation (the moon’s albedo (reflectivity) is 5%, roughly the same as coal dust.) Even up close, you will only able to spot mines on the moon because they’ll be the clean looking areas.

The only thing that will ever noticeably mark the face of the moon will be the faint lights of bases/cities during the new moon.

1. It makes a better place for long-term occupation because it has gravity. People work better with at least some gravity. So any sort of manufacturing operation that must be done in vacuum might be better done on the moon than in orbit because things stay put where you place them. A lunar “clean room” could be one heck of a semiconductor plant.

2. An acclimation point to get astronauts experiencing long periods of zero G acclimated to gravity before a return to Earth.

3. Launch facility and by extension vehicle manufacturing facility. It is much easier to place a satellite into Earth orbit from the moon. You have no atmospheric stresses at launch (no fairings needed, for example), moon’s gravity is much less requiring much less fuel to launch a given payload, and once launched it can be configured to “fall” into the correct orbit of Earth with some fuel probably needed for braking but not for accelerating into that orbit. Vehicles going into interplanetary space can also get an extra boost toward their destination by launching them when they are getting a velocity assist toward their direction of travel from the moon’s orbit around earth.

4. If you are going to have a manufacturing/living/launch facility, you will want to mine as much as possible locally and not have to send it from Earth.

(1) Over the long haul, I would agree that lunar mines would pay. But who will do the initial investing, and why?
(2) Why would NASA permit successful competitors to appear?
Every organization’s first purpose is to survive, and in govt that means maintaining a monopoly.

Other than that, the US won’t do it, our space program is dead. It’s death spiral began with the last moon landing. It’s been a long lingering death but I think Obama finally pulled the plug. Oh it’ll remain as a zombie, an undead bureaucratic nightmare tasked with building large useless rockets with no mission but to service every congressman’s district with unproductive jobs program. Nothing ever dies in government it’s just retasked for graft and corruption so don’t confuse NASA’s continued existence with an actual space program.

Oh btw, don’t believe government will leave private, commercial space projects alone. Evidence: Nasa has already attempted to hijack directorship of all such programs. They appear to have been beaten back for the moment. It won’t last. The Fed’s will come back. It’s not IF it’s WHEN.