The Market Value of the Stairway to Heaven

• policy
• theskyatnight
• space

In response to the frankly ambitious Japanese announcement that they could make a ladder into space for 10 billion Yen1 and have it running in our lifetimes, I was asked to write a guide to the construction of a space elevator for the March edition of The Sky at Night magazine, out now.

Don't be confused — the cover varies depending on which hemisphere you're in. Northern Hemisphere residents get an 'observation challenge' with 40 objects to spot — but if you're in the Southern Hemisphere, it's really a little bit too challenging, since there's a couple of billion tons of planet in the way. Therefore, the lead story in Australia, New Zealand and South Africa is yours-truly's account of the space elevator.

The article covers why, what, if/when and how, broken down into 10 fairly tricky steps. There just wasn't room to talk about how space access would change society, or how nanotech fits into mega-construction. So in the absence of a 12 step guide to weaning myself off the obsession, I'm writing these accompanying articles to include aspects that just didn't fit into TSAN.

Um, Space Elevator?

The space elevator is a very simple and very audacious idea — a 22,000 km long rope, suspended from its centre of mass in orbit and reaching down to the surface of the Earth. Once this is in place, you can escape the gravitational well for just the effort involved in climbing a rope. Compare this to the massive amounts of fuel needed to accelerate our 2,000-ton shuttles to escape velocity, and to the 2% of launch mass that comprises the actual payload, and the elevator presents a totally new epoch in interplanetary travel.

I concede that at the moment, the elevator is almost infeasible, both as a feat of engineering and as a global collaboration. But I persist in the belief that easy access to space would revolutionise human society as much as the invention of the combustion engine, and somewhat more beneficially — and so I dare to hope for a stairway to the stars.

But we've already gone into space...

Don't get me wrong, I like big phallic rockets as much as the next girl. It is truly, staggeringly, impressive that people have walked on the moon. It's just a shame that in the forty years since, not much has happened when it comes to expanding our little habitable bubble. We sent a probe to Mars, and we've bowled four little gizmos out of the solar system. Okay, so maybe that is a little bit impressive, but the number of humans who've even achieved what Gagarin did stands at about 450. Yes, that does include some 'space tourists' who've paid millions to warm their buttocks on the spare seat of a Soyuz capsule (although not for much longer), but this isn't because space travel has become more accessible — rather, billionaires have become more ambitious. The fact remains that the closest an average person will come to space travel is navigating via GPS.

And I care why?

Earth is a somewhat over-protective mother, and holds us back from achieving our full potential. Resources on our home planet are limited, and our rates of consumption are only increasing. Regardless of the recent drop in property prices, land is still at a premium, for agriculture, water and mineral rights as well as holiday homes. Toss in the rising sea levels, and increasingly dangerous weather systems, and living-space becomes a luxury.

To quote Kurt Vonnegut, we're all packed together like drupelets. While I would like to think that when birth control is freely available to third world countries, the birth rate will drop off, I don't think it will drop off sufficiently to allow supply to overtake demand. While we want detached Barratt homes and shrubberies, while governments offer subsidies to breeders and turn away immigrants, it's going to be a crowded environment in the future. This isn't inevitably a problem, since people can get used to pretty much anything and it's not fatal to live in a small room, but given the increased demand for food and the fact that cows and potatoes have extension in space, it's worth considering.

The problem is, Earth's surface is two-dimensional (we don't really use height when it comes to property rights, just longitude and latitude), but because it's mounted on a 3D sphere it's bounded. By now, all areas on it (except possibly Antarctica, and let's see how long that lasts) are claimed. If you want more territory, someone else has to lose some. It's zero-sum — noone gains anything, except at the expense of others. Humanity as a whole does not benefit. This is the same for activities as well: if you want to grow biofuels, then you have to grow less food. If you want more palm oil, you have less orangutangs. There are fundamental limitations imposed by our geometry and our gravity well.

You just like freeze-dried ice-cream

In space, there are no such topological boundaries. While the solar system is essentially flat, the space within it is equally inhospitable in all directions, and the sun gives off energy in a sphere. Once you can get into space, all of it is available. It's true that the asteroids (which are ripe sources of minerals, methane and possibly even good old H20) are localised, but they can be moved. It is only necessary to reach them, and then they can be towed to wherever you've decided to set up home.

And these are large reserves. Although some substances like fossil fuels are probably rare throughout the solar system2, minerals like platinum, gold and uranium are plentiful in the asteroid belt. And when I say plentiful I mean really plentiful. In the words of John Lewis, a planetary scientist at the University of Arizona, "The smallest (2 km) Earth-crossing asteroid, 3554 Amun, is a lump of iron, nickel, cobalt, platinum, and other metals; it contains 30 times as much metal as humans have mined throughout history, although it is only the smallest of dozens of known metallic asteroids. It would be worth perhaps US $20 trillion if mined slowly to meet demand at 2001 market prices."

When in space, priorities change. The important things are energy, food and air, not territory or property. Of these, energy is free, in the near solar system at least. At the distance Earth orbits at, the sun chucks out about 10kJ per metre squared of solar cells you can be bothered to erect, every second. And the (admittedly pathetic) arguments people throw at Earth-bound solar power don't apply when you're in space and there is no night-time or weather. Further out, you can slake your archaic addiction to liquid fuels with Titan's methane seas. If you're feeling a bit more modern, Jupiter has a mass of 300 times earth and is made of mainly hydrogen — which can be combined with nuclear power to give this amazing-looking engine:

Operating in space eliminates most of the problems with nuclear power: to get rid of waste you just launch it away from you, and the same approach of 'drop it and run away' works in the event of meltdown.

So energy is as easy as Sunday morning with a butler. The other stuff, to keep our meat bodies going, is the fractionally trickier bit. Oxygen and water can be mined from the asteroids and planets, but you'd need to husband your reserves. Of course, some people on Earth in the equatorial regions already have to do this (with water, not air, obviously). If we discard the possibility of just filling the hold with beef jerky and crisps, food is somewhat tricky; ideally you'd want to set up a closed, self-sustaining environment. There are some ongoing attempts to work with this — although Biosphere 2 failed catastrophically, smaller biospheres which can keep going for 4 years are available commercially. I don't think this problem is insurmountable, and certainly it's peanuts compared to ensuring fair distribution of wealth on Earth.

You may notice that to get the important things detailed above, what's important is the technology for doing it, not the possession of resources or whose father beat who in a muddy field a couple of centuries ago. The Solar system is big enough for everyone to share3 and too big for any oligarchy to lay claim to (fingers crossed). This entails a fundamental shift from being wealthy because of historical accident, to being wealthy because you're equipped with good tech (an inventor or supporting an inventor) or because you're prepared to hunt for rich lodes. A proper meritocracy, in other words.

Well, I'd like that, anyway.

1. Now looking increasingly cheap when rendered in the SI unit of bail-outs. ←

2. The ease with which hydrocarbons can be produced is still a topic of debate; hopefully in the future I'll post an astrobiology (beginnings of life) article about how to make your first organic molecules, using only ordinary household materials. ←

3. Oh no, I'm a communist! ←