Friday, July 01, 2011

Is space exploration over?

The Economist has an article about how the age of space exploration is over. They are a little late on this announcement, as the peak distance that any human has traveled from Earth was reached about 40 years ago. The first age of space exploration has been over for a while.

But does that mean that our adventures in the Final Frontier are over forever? I'm not so sure. After all, think about maritime exploration. For thousands of years after the first canoe was launched, the high seas remained basically empty of human ships. Once we got the technology to conquer the seas, however, we quickly did so.

What technology would be needed to conquer space? It's clear that what we use now is too expensive for large-scale use. To reduce launch costs from Earth, we need either mass drivers, laser propulsion, or something of similar energy savings (a "space elevator", sadly, will probably never exist).

But we need more than that, because even with cheaper launch systems, manned space exploration is extremely expensive, especially given the radiation shielding and other add-ons that we'll need for interplanetary travel. What we need is a bigger, better energy source. With the Earth energy-constrained as it is, there are no fossil fuels to spare for Mars missions, and we'll be lucky if we get renewables to the point where they save us from backsliding to the iron age. That means that we need nuclear fusion.

But in addition to the means, we need a reason to go. What is in space that we can use? Well, if fusion becomes a power source, we might want to mine tritium from other planets. And with fusion, terraforming of Mars might one day be possible (fusion is really that good as an energy source!).

As for interstellar travel, that is really and truly off the table without technological breakthroughs so advanced that we currently can barely imagine what they are.

So basically, no fusion, no space adventures. But if we do invent fusion, then the whole equation changes, not just for space travel, but for every conceivable human activity. Hence, we should focus our engineering efforts not on manned space travel, but on fusion power. And if we ever succeed, then the Second Age of space exploration may begin, and the Economist's article may come to look as silly as those medieval assertions that the Atlantic could never be crossed.


  1. What's actually galling here is The Economist's no-big-deal attitude. Think a moment: we're in a universe at least 30 billion light years across, holding several hundred billion galaxies with on average several hundred billion stars for each, which will last for septillions of years to come. Our knowledge and our wealth have been expanding exponentially for centuries now, and curiosity and wanderlust seem baked into our genes by millions of years of natural selection.

    And the Economist blandly consigns us all, for all time to come, to one small planet about one rather ordinary star, where presumably we will spend the next few million years squabbling with one another for natural resources, social position, and other goods until the swelling sun brings our extinction. Shouldn't the Economist at least say "too bad"? I've seen the magazine spend more ink and more emotion on the closing of Victorian-era train stations.

  2. Some people question whether "exploration" is even the right term - and I'm one of them. If and when the first human beings set foot on Mars, we'll know far more about it than the first explorers of North America knew about that continent.

    Space *recreation* - sadly, only for the rich - has a bright future however.

  3. Michael Turner --

    And your point is?

    I lived until recently in Los Angeles. Consider that LA is pretty well a known commodity by now. There are maps of the place, detailed maps, whole books of maps. There are pictures of the place in magazines. There are geologists wandering over the area, there are people checking out the weather and people looking at water quality and even some hopeful folks on the outskirts panning local streams for gold.

    Wierdly enough, despite the depth and totality of our knowledge of Los Angeles, people actually choose to live there. More than a few dozen people, in fact. Rumor has it that somewhere in the last couple of centuries, in defiance of all sane economic reality, LA ceased to be an empty, howling wilderness. But that's probably just science fiction!

  4. Space is where we should be getting the renewables to keep us from sliding back into the iron age as you put it. Once we have even a token colony on the moon, it's very easy to start creating photo-voltaic cells in space from the abundant lunar surface deposits of silicon. They would be about 5-6 times more efficient then earthbound ones due to consistency, lack of cover and no day-night cycle. Then microwave energy transmission beams that energy back down to any city where there is demand on the half of earth that the satellite is above.

    With a profitable export industry on the moon, it makes sense then to expand the lunar colony until either energy becomes so cheap that our problems are over or we have committed the resources for serious space colonization like O'Neil cylinders using lunar materials.