Mining asteroids sounds like a very lucrative activity that has almost endless possibilities with the promise of limitless resources. The tricky problem about that is that space is hard to get to. You have to overcome the seemingly irresistible pull of the Earth’s gravity, which requires a lot of energy. The current way we mange to do this is by the use of rockets that rely on chemical reaction to produce an enormous amount of heat and gas expansion that we direct downwards, which causes the rocket to go up. It costs a lot of money to put things into space, around $5000 per kilo depending on whose rocket you use and what compromises you are wiling to take. This is the issue that many of the major space entities are grappling with and even reducing costs through the use of re-useable rockets like SpaceX isn’t going to create the magnitude change in cost that will make asteroid mining supplant terrestrial mining. To get to the Moon or to Mars, large payloads are needed to be launched into space. SpaceX is planning on building a large rocket called the Big Falcon Rocket that will be topped up with fuel in orbit prior to heading off to Mars, which is a way of getting large payloads put together in orbit. The ideal situation is to build things in space from resources obtained in space, such as asteroids or building stuff on the Moon. Most concepts of establishing a presence on Mars have a reliance on some sort of self sufficiency for fuel being sourced from the red planet, and with a whole planet to select from, it’s critical to land in the right spot to make the most of local resources.
It’s not a great leap in logic to wonder why we aren’t building spacecraft in space, not just assembling them from Earth made modules like the International Space Station (ISS) but mining, refining and constructing from materials obtained in space. This potentially lucrative concept has not been lost on many people with plenty of discussions about asteroid mining being had around the world. How easy is it to capture an asteroid, mine it and turn it into something useful? The issue at the moment is pure economics, it’s very expensive to launch stuff into space and dangerous and complex to go to an asteroid and extract resources. It’s even very tricky just to find one to go to. Near Earth asteroids offer the best chance of finding valuable resources and do not present an impossible task of getting to them.
Going near Earth
Three types of asteroids have been identified that would fit as candidates for eventual mining, they are C, S and M types. The C-type asteroid is mainly made of ice and could be used to produce fuel, they also have some carbon and phosphorus so could also be useful in supporting the production of food. S-type asteroids have a lot of metal including nickel, cobalt, gold, platinum and rhodium. M-type asteroids are even more metallic than S-types, but are very rare. Finding one of these asteroids is only part of the problem, to mine it, the choices include bringing it back to Earth and inserting it in a safe orbit where the asteroid can be mined. The other option is to extract the resources from the asteroid where it is and only bring back the obtained material. There’s plenty of companies established around the world with desires to extract resources from asteroids, though none of them have made any real progress.
OSIRIS-REx was launched on 8 September 2016 and is intended to go to an asteroid and return with a sample. The asteroid selected is 101955 Bennu which is a C-type asteroid. The purpose of the mission is not to mine the asteroid or try out mining techniques but to obtain a bit of the asteroid so it can be analysed back on Earth to gain a better understanding of the origin of the Solar System. The side benefit of the mission is that in getting the sample and returning to the Earth it has to do a lot of the same things that would be required for resource extraction, just on a much smaller scale. The reality of the difficulty of asteroid mining is bought into context when you consider the OSIRIS-REx mission costs nearly $1 billion and will only return a few tens of grams of material to analyse.
It’s unlikely we will see much progress on asteroid mining until it’s significantly easier and cheaper to launch equipment into orbit and it hardly seems feasible that someone would go to all of that effort to have the material just end up back on Earth rather than be used to build something in space.
Or rather making a base on the Moon
A more feasible scenario seems to be the establishment of a base on the Moon that is able to extract water for the creation of fuel and possibly other materials for construction. Moon Express is a private company that has a strategy of “arrive, prospect, return”. The first mission is planned to be the Lunar Scout mission which is advertised as the first commercial flight to the Moon in history. Moon Express plan to use a Rocket Lab’s Electron as the launch vehicle for their Lunar Scout sometime in 2018. It’ll be interesting to see if it goes to plan. They intend to follow up wth a robotic lander that will look for resources and then another mission that will try and return samples to Earth. Moon material currently on Earth could be worth as much as $50,000 per gram based on the cost of getting it from the Apollo missions, so if Moon Express can bring back a few kilograms then they might be able to make some money out of it!
It’s unlikely that the terrestrial mining operations of the Earth are going to be under any threat soon from space mining. It seems that we need a few more developments in launch technologies before the prospect of mining asteroids becomes a reality.