The amount of solar energy that passes closer to us than the Moon is equal to the whole world's fossil fuel reserves every minute. That's not just energy independence, that's a superabundance of clean energy, as long as the Sun lasts. I think that is worth a small amount of R&D funding. Tapping that energy is easier if you can use equipment made locally in space, rather than hauling it all up from Earth. We have no production capability in space at the moment. If we can reach the "bootstrap point", where equipment in place can make more equipment, then we can realize whatever goals we set. The taxpayer's investment will be paid back many times over from higher economic activity.

> And putting it into a different orbit would be much more difficult than an Earth launch.

This is factually incorrect. Using electric thrusters, and Lunar gravity assist, you can retrieve asteroid rock for about 2% of the rock's mass in fuel. Since part of what you can extract from the rock is more fuel, the mining operation is self-sustaining until the equipment wears out. A reasonable estimate is you can fetch 200 times the mass of a fueled space tug over it's life.

> there is zero infrastructure, and that's going to be incredibly expensive to build in space.

Bootstrap from a small starter kit. Use local materials for the self-expansion. See http://en.wikibooks.org/wiki/S... for details.

> Imagine the utility of a programmable satellite factory.

I don't just imagine such things, I'm working on building them ( http://en.wikibooks.org/wiki/S... ). Instead of trying to launch a whole space refinery and chemical plant, you send a starter kit (a "seed"), and use it to progressively build the rest out of local energy and materials. Since the laws of nature are the same everywhere, the Seed Factory concept works just as well on Earth, so our first generation design is for here. Later versions will be for more hostile environments like the oceans, deserts, ice caps, and space. Where it gets really interesting is using an expanded factory to make new starter kits. This is very similar to how biological plants reproduce. An acorn doesn't make another acorn directly. It grows into an oak tree first, then produces more acorns.

The "Common Heritage of Mankind" principle wasn't enacted, because the US and other spacefaring countries never signed the second Moon treaty. We follow the first Outer Space treaty, which prohibits territorial claims of celestial bodies. Use of a celestial body is allowed, with certain restrictions, like no weapons of mass destruction. Mining valuable resources falls into the allowed use category.

There are three reasons. The first is the main use for asteroid materials is in space, where they already are. Radiation shielding and fuel are the easiest products to make at first. To get anything from Earth into space is expensive, and gets more expensive the farther you go. The second is certain elements sank to the core of the Earth along with the iron, and are therefore very rare. Asteroids can contain hundreds of times higher concentrations. Even though asteroid mining isn't going to start out cheap, these minerals may be worth extracting, as a side effect of the bulk uses like shielding. Thirdly, the Earth has an average thermal gradient of 25C/km. So if you go down 8 km (5 miles), typically it will be 200C, which is really hard on the mining equipment. Some oil wells go that deep, but the drilling equipment stays on the surface, only the cutting bits are at the bottom.

99% of Near Earth Asteroids take less fuel to reach than the surface of the Moon. That's partly due to the lack of a deep gravity field, partly due to being able to use the Moon itself to slingshot vehicles towards the asteroids, and partly because with a shallow gravity well you can use all electric thrusters, which are ten times more efficient.

I'm not saying to ignore the Moon, it has it's uses. But we should not ignore an easy to reach resource that is *differentiated* into different minerals and ores. The Moon has a blended surface due to repeated impacts throwing stuff around. It doesn't have the same kind of concentrated metals that a Type M asteroid does.

> They'll go dress to be unidentifiable on video,

Just carry a mirror in front of you until you are in spray paint range.

For extra credit, hack the communications channel, and take over the bot.

> EXTERMINATE

That only applies to the robot pest control version, with the insecticide spray arm.

Dry rock (gravel) can store energy at about $1/kWh. It doesn't get any cheaper than that. How you use that storage capacity is to use a solar concentrator to heat a working fluid (usually water). Some of the steam goes directly to turbines to make electricity. The remaining hot water or steam goes to a heat exchanger, and a fan circulates air through that and the rock bed. When the Sun isn't shining, you reverse the fan, and suck heat out of the rocks to heat water/make steam again.

To keep the rock thermal bed hot, you surround it with "vacuum powder insulation", which has about six times lower thermal conductivity than fiberglass. On a large enough bed, that will stay hot for days. That's because thermal loss goes as the square of the thermal bed size (area), but heat storage goes as the cube (volume). So the bigger it gets, the longer it can store heat.

Batteries are not really a solution for storing power grid amounts of energy. A valley full of water (hydroelectric) or the equivalent of a gravel pit full of rocks (thermal storage) are answers because the raw materials (water or gravel) are really really cheap.

Solar-thermal with storage. You get power at night.

The 400 MW Ivanpah solar thermal plant is on the same power line as Hoover Dam (both are near Las Vegas). It didn't need its own storage unit, because the dam already provides huge amounts of storage. Whenever the solar plant is running, the dam can save water for later. Not all locations have an existing dam conveniently near, so solar-thermal will need to build their own storage units on-site. There are several options, and which is best to use is an area of active research.

No energy source is truly renewable. Solar comes from fusion in the Sun, which has a finite fuel supply. It's just a really big supply on human time scales. Ultimately all "green" energy sources trace back to nuclear sources, either fusion in the Sun (solar, wind, hydroelectric, biomass, ocean thermal), or radioactive decay in the Earth (geothermal). For that matter, fossil fuels are fossilized sunlight, so are also nuclear-based also. They just have a more limited inventory.

What renewable means is there is a constant flow of energy that can be tapped - the Sun shines every day. New fossil fuels aren't being created anywhere near the rate we are burning them, and new nuclear ores aren't being created at all.

Sorry, but you are quite wrong about that:

http://googlegreenblog.blogspo...

Like anyone who has more than a smidgeon of understanding about power grids, Google understands that no single power source can satisfy varying demand. So they are investing in a variety of sources: http://www.google.com/green/en...

> Santa Claus isn't real.

Saint Nicholas of Myra is quite real. His bones are buried in two places in Italy (long story). He's the original whose story and image have been mutated over the centuries. The modern mall Santa image comes from Clement Clark Moore's poem, the Saturday Evening Post, and Coca Cola (http://www.arts-stew.com/wp-content/uploads/2012/12/1936-Vintage-Coca-Cola-Christmas-Ad.jpg). The modern version incorporates no small amount of pagan imagery.

Space is already a $300 billion/year industry. Just servicing and fueling GEO commsats would be worth billions a year. That's enough to finance mining and repair stations in orbit.