Artist concept courtesy of NASA

Artist concept courtesy of NASA

I’d be willing to bet that the great majority of science fiction stories set in the future include a significant human presence in outer space as a given, even if the stories themselves aren’t about space. Space travel is just a huge part of the SF imagination. Human colonies on the Moon, Mars, moons of the gas giants, and at least some asteroids. Regular traffic to and from Earth, with established shipping routes weaving through the solar system for passengers and cargo. Maybe huge colony ships or faster-than-light spacecraft charging their way toward other suns.

But why do we seem so sure that will happen? Just because it would be cool?

That isn’t the way the human world works. To be frank, the forces that drive human exploration and expansion are usually necessity and greed. We go to new places because there isn’t enough room at home (or resources, or peace and prosperity) or because somebody stands to make a lot of money. But what about going beyond our own planet?

I’ve discussed the economics of space mining before. In these days when private enterprise is getting into the space launch business, companies like SpaceX and Orbital Science still need $27,000 to $43,000 to take a pound of cargo and put it into orbit. Even in the space shuttle days (because it could carry much more cargo) the price per pound was about $10,000. Now imagine the amount of steel and other heavy stuff needed to build a big transportation hub and/or warehouse complex in orbit. Or the weight of construction equipment needed to be hauled to the Moon to dig mines. Or even just the fuel to power the equipment and spacecraft. Water is about the cheapest fuel around (broken into hydrogen and oxygen), but it’s still heavy (that half-litre bottle you like to drink weighs more than a pound).

It’s true that the first three hundred kilometers of the journey from Earth are by far the most costly, so there have been proposals to replace rocket boosters with magnetically-levitating launch tracks, or a space elevator with cables made of nanomaterials hung from giant stations in geostationary orbit. There are lots of creative launch alternatives, but such things would cost billions, if not trillions of dollars to build. And all of that is just to create the infrastructure that mining and shipping operations would require.

What end product could possibly be worth such an investment? Even if speculations are true that some asteroids might contain as much platinum and related metals as have ever been mined on Earth (only an estimated 16 tons), with a price this week of around $950 per ounce that still only amounts to about $480 million. It would take a lot of asteroids for investors to make their money back, and that’s assuming the demand and price for platinum metals would stay high (which it wouldn’t with such large amounts dumped onto the market).

Some will say that there’s huge value in research and certain kinds of chemical processing that can only be carried out in zero gravity. That may very well be true, but such operations would be best placed in Earth orbit, close to the consumer market—there would be no need to colonize other planets for them.

All in all, I’m of the opinion that, at least until the Earth completely runs out of the mineral resources we need (including recycled materials), space mining with Earth as its main market won’t be the driver that creates a system of colonies and industries throughout the solar system. But I used italics because, if we create colonies on other planets and moons for some other reason, then space mining will be much more viable to supply those outposts than having to ship material from Earth.

So my point is that, if a widespread human presence in space beyond the Earth is ever to happen, it will be for reasons other than profit.

“Running out of room at home” could be one such reason—we don’t yet have our population growth under control, and rising living standards are creating a demand for food and other goods that may be beyond our beleaguered planet’s ability to supply for much longer. But as science fiction buffs, we can speculate about others:

- pollution, climate change, or nuclear war makes the planet unliveable.

- runaway products of genetic engineering or nano-engineering make the planet unliveable.

- a cosmic catastrophe like an asteroid strike, solar flare-up, or magnetic field disruption makes the planet unliveable.

- the Earth is about to be swallowed by a black hole (and would therefore be unliveable!)

Or possibly if the uber-wealthy 1% and the exploited 99% just can’t live together on the same planet any longer.

There are happier possibilities too:

- if a very inexpensive gravity-controlling technology were developed (especially in combination with force-field shields against radiation). Spacecraft might be less costly than submarines.

- if a faster-than-light spaceship drive were invented. We’d have a much greater incentive to explore other star systems (spared hundreds of years of travel time).

- if life is discovered on other planets or moons. We’d feel compelled to investigate it and possibly even protect and nurture it long-term.

- if research discovered that living in space or on other worlds provided a significant benefit to human health and lifespan.

-if genetic engineering made humans able to thrive under the harsher conditions elsewhere in the solar system (lower gravity, higher radiation, different atmospheres and temperatures).

Or if an advanced alien race were to make its presence known to us—whether in peace or in conflict—we’d have a strong impetus to establish a firm foothold in space.

Will there ever be humans living and working all over the solar system and beyond? I think so. Eventually. But it’ll take a very compelling motivation—maybe many compelling motivations—to make it happen. For once, the lust for money won’t be enough.