Friday, February 03, 2006

We're Whalers On The Moon


In a shocking turn of events, I have to learn about space nerdy goodness from another blogger. I must be getting old. Via Angelica:
MOSCOW (AP) – The head of a leading Russian space company said it was considering plans to set up a permanent moon base by 2015, a statement that appeared to be an effort to win government funds rather than a specific action plan, news reports said Thursday.

Nikolai Sevastyanov, the head of the state-controlled RKK Energiya company that built Soyuz and Progress spacecraft, said that mining helium-3, a potential rich source of energy, and harnessing it back to Earth would be a key priority in the moon exploration program, the Gazeta.ru and Lenta.ru Web sites reported.
Helium-3 fusion is a real thing, alright. The problem with mining it from the lunar soil is that you're literally talking about trying to collect He3 from dirt, when the concentrations we're talking about are roughly 4 parts per billion. The task is so massive that it makes collecting gold from seawater look easy.

Yes, a space shuttle could bring back to Earth 30-35 tons of He3, which would be enough to power the entire planet for a few months. But how much of the moon would we need to mine in order to get those 35 tons? Roughly 8.75 million tons of lunar dirt. That's a 1-250,000 ratio. Now, a few years ago I would have said that was madness, but the positively giddy way that the US, China, and India have invested in the tar sands (which are oddly similar) makes me more optimistic about He3 mining.

There are, of course, some problems. The biggest is the same one as always with lunar projects - the moon's gravitational pull. Getting anything out of the moon will be much more difficult than from a smaller body. On top of that, He3 refining will require a huge amount of energy itself. Then of course there's the problem that, even if we had abundant He3 here on Earth, we still don't have a working fusion reactor.

All of these problems are solvable. But if we're really going to talk about massive space infrastructure to bring electricity to Earth, my preferred pipe-dream is the Solar Power Satellite. Essentially, we would build acres of solar panels in geosynchronous orbit, where the Sun shines 99% of the time, and beam the electricity down via microwaves. The cost of electricity would be about the same as with the optimistic numbers for fusion, but it wouldn't be "nuclear" so it avoids the bad branding, and the satellites could be built out of asteroids instead of lunar dirt, meaning that getting the stuff to build them with would be much cheaper.

All of this is nice dreaming - and don't get me wrong, I wish RKK Energiya luck - but if we're looking for anneutronic fusion possibiilties (i.e., fusion power sans radiation) hydrogen-boron fusion still sounds like a better bet, especially if the boys at Focus Fusion are right. p-B fusion is even less radioactive than He3 fusion, though it is more difficult to "ignite" than He3, which is itself harder to ignite than the traditional Deuterium-Tritium reaction. The other benefit is that p-B fusion doesn't require anything exotic like He3, Tritium, or even Deuterium. All you need is regular hydrogen and regular boron - and a sufficiently dense plasma to initate fusion. There's the rub.

Another option for collecting He3 that might actually be more successful would be collecting it from the gas giants. Jupiter, Saturn, Uranus, and Neptune all have literally billions of years worth of He3 free-floating in their atmospheres. The problem with Jupiter is that it's gravity well makes collection impossible at this point. Saturn would be more difficult, but possible. But the far more likely candidates are the outlying gas giants Uranus and Neptune. Their smaller gravity wells makes collection much easier. One problem - they're a minimum of 6 years away.

Which leads us to the biggest chicken-and-egg problem of space exploration: The solar system has plenty of resources for us to get at - energy and mineral wealth beyond counting. The problem is that we can't get at it. Once we can get at He3, for example, a fusion rocket could cut the travel time to Neptune to something like weeks instead of years. But we can't make a working fusion rocket until we get a decent fuel. Which we can't get until we send someone to Neptune to get it... etc.

But we will have to go out there some time. We're rapidly running down our stocks of critical metals here on Earth - there's serious questions about how much longer our supplies of platinum, or even copper will last. Meanwhile, the smallest metal-rich, near-Earth asteroid holds more platinum, gold, and nickel than have ever been mined in the history of human industry - something on the order of $20 trillion, according to mid-1990s prices.

The idea of energy or mineral shortages is an illusion caused by our perspective - from down here, it looks like a real problem. Out there, with free solar energy and more minerals, water, and organic chemicals than exist on Earth, the idea that we're lacking in anything but imagination and courage is laughable.

2 comments:

Ronald Brak said...

I'm a little confused. How can earth be running short of some metals if the smallest metal-rich near earth asteroid holds more platnium gold and nickel than has been mined in human history? For surely these asteroids have been smacking into earth for billions of years? Wouldn't it be easier to find some that have smacked into the earth and mine them? I realize there are problems with this. Metorites come down pretty randomly and it's rare to find one more than a meter across that stays in one piece, but they do have the advantage of being here rather than out there. I believe that some impact sites have already been mined, although I'm not sure if they realized they were mining meteorite remains at the time. I have no idea how profitable these asteroid mining projects were.

And although metal meteorites found on earth do contain some gold and platinum and other expensive metals, it's a tiny amount per kilo and isn't concentrated in one spot as can be the case with metal deposits on earth, so it would be a very difficult process to get say the gold out of a metal rich asteroid. You could vapourise the asteroid and use a gas centrifuge to seperate the elements I guess, but it would probably be easier to do that to old mine tailings on earth, or to low grade ore deposits, or possibly just dirt.

Anonymous said...

By including that image, you have opened a Pandora's Box of Futurama quotes!

The most relevant:
"Nobody doesn't like Molten Boron!", as an advertising jingle.