Mining the Moon

If you were transported to the Moon this very instant, you would surely and rapidly die. That’s because there’s no atmosphere, the surface temperature varies from a roasting 130 degrees Celsius (266 F) to a bone-chilling minus 170 C (minus 274 F). If the lack of air or horrific heat or cold don’t kill you then micrometeorite bombardment or solar radiation will. By all accounts, the Moon is not a hospitable place to be.

Yet if human beings are to explore the Moon and, potentially, live there one day, we’ll need to learn how to deal with these challenging environmental conditions. We’ll need habitats, air, food and energy, as well as fuel to power rockets back to Earth and possibly other destinations. That means we’ll need resources to meet these requirements. We can either bring them with us from Earth – an expensive proposition – or we’ll need to take advantage of resources on the Moon itself. And that’s where the idea of “in-situ resource utilization,” or ISRU, comes in.

Underpinning efforts to use lunar materials is the desire to establish either temporary or even permanent human settlements on the Moon – and there are numerous benefits to doing so. For example, lunar bases or colonies could provide invaluable training and preparation for missions to farther flung destinations, including Mars. Developing and utilizing lunar resources will likely lead to a vast number of innovative and exotic technologies that could be useful on Earth, as has been the case with the International Space Station.

As a planetary geologist, I’m fascinated by how other worlds came to be, and what lessons we can learn about the formation and evolution of our own planet. And because one day I hope to actually visit the Moon in person, I’m particularly interested in how we can use the resources there to make human exploration of the solar system as economical as possible.

A rendering of a possible lunar habitat, featuring elements printed in 3D with lunar soil. European Space Agency/Foster + Partners

In-situ resource utilization

ISRU sounds like science fiction, and for the moment it largely is. This concept involves identifying, extracting and processing material from the lunar surface and interior and converting it into something useful: oxygen for breathing, electricity, construction materials and even rocket fuel.

Many countries have expressed a renewed desire to go back to the Moon. NASA has a multitude of plans to do so, China landed a rover on the lunar farside in January and has an active rover there right now, and numerous other countries have their sights set on lunar missions. The necessity of using materials already present on the Moon becomes more pressing.

Artist’s impression of what lunar in-situ resource utilization might look like. NASA
Anticipation of lunar living is driving engineering and experimental work to determine how to efficiently use lunar materials to support human exploration. For example, the European Space Agency is planning to land a spacecraft at the lunar South Pole in 2022 to drill beneath the surface in search of water ice and other chemicals. This craft will feature a research instrument designed to obtain water from the lunar soil or regolith.

There have even been discussions of eventually mining and shipping back to Earth the helium-3 locked in the lunar regolith. Helium-3 (a non-radioactive isotope of helium) could be used as fuel for fusion reactors to produce vast amounts of energy at very low environmental cost – although fusion as a power source has not yet been demonstrated, and the volume of extractable helium-3 is unknown. Nonetheless, even as the true costs and benefits of lunar ISRU remain to be seen, there is little reason to think that the considerable current interest in mining the Moon won’t continue.