Circling the Sun between Mars and Jupiter are billions of asteroids, chunks of rock ranging in size from footballs to gigantic Ceres, 1,000 km (620 miles) across. Most of these are rocky, but even these have some amount of materials that are useful, including water ice, hydrogen, oxygen and even precious metals.
They’re the floating convenience stores of space, and can be tapped for supplies needed to explore deep space. Many of them are on orbits that also take them near the Earth, which makes them far easier targets for space missions, requiring less fuel and time to visit.
One company, Planetary Resources, has already announced plans to do exactly this. Their idea is to mine near-Earth asteroids for material, creating depots of air, water, and other supplies for future space missions. Their plan is not pie-in-the-sky; in fact they think – and I agree – that in the long run they can make money in this venture.
A critical aspect of this is being able to mine asteroidal material and process it, which Nasa and its contractors are studying. One line of thinking is that mined metals can be used to build structures in space that would be very difficult and pricey to construct on Earth and launch. Examples abound, including big spacecraft to use for crewed exploration of the planets, giant telescopes in orbit, space stations, and more. While the cost of the International Space Station (ISS) is estimated to be $100bn, much of that was simply getting previously-built components into space in the first place. If you already have those pieces in space, the cost is far less.
Smelting material in the near-weightless environment of an asteroid is one thing, but creating complex components of spacecraft is another. Manufacturing is likely to be easier in gravity, and the Moon is a perfect compromise for this.
Getting the materials to the Moon is not hard from an asteroid mining operation. And once built, getting even massive components off the Moon’s surface is far, far easier than it would be from Earth due to lower gravity and lack of air (it took a tremendous Saturn V rocket full of fuel to get to the Moon, but only the tiny Apollo ascent module to get back off). Building vehicles and other space-based structures on the Moon is vastly easier and less expensive than it would be here on Earth. From there, the rest of the solar system is an easy trip.
Staying in space
Mind you, I’ve skipped some steps here. We need cheaper and more reliable access to space, and a pathway established so that the public has a clear understanding of how all this will be done. With the recent successful launch of the SpaceX Falcon 9 rocket and Dragon capsule to the ISS, we may very well be well on our way to those two steps.
And asteroid mining is just one example of the usefulness of space; others will inevitably arise. In space exploration, there are always benefits found along the way that are difficult if not impossible to predict.
Which will lead to the hugely important third step: this needs to be sustainable. We cannot go into this with the idea that this is a single goal only. China is building a space station (the first module is already in orbit) and has plans to go to the Moon; India and Russia have made similar musings – but it would be a big mistake to think of this as a second space race.
Why? Put it this way: what happens when you win a race? You go home. You’re done. This kind of thinking doesn’t lead to sustainability, and that’s why Apollo was canceled prematurely.