They aim to mine it for water ice that could be the key to re-fuelling spacecraft away from Earth, and to hunt for desirable "rare earth elements".
Texas-based Shackleton Energy Company (SEC) has plans to separate the Moon's water ice, found at the two poles, into its constituent elements of hydrogen and oxygen and sell it as propellant for spacecraft.
With an estimated 1.6 billion tonnes of water ice on the Moon, SEC will use a combination of humans and robotics to do the mining. After using it to fuel their own mining equipment, rovers and life-suport, the majority will be sold off via a "gas station" situated in Low Earth Orbit (LEO).
"LEO is where we will have monstrous electrolysers to convert the water to propellants on an on-demand basis," Dale Tietz, the company’s chief executive officer, told Physics World magazine.
Currently, most of a craft's propellant is used up trying to reach the escape velocity needed to move away from the Earth's gravitational pull, and it is simply too expensive to carry more than is necessary.
As the Moon has just one-sixth of Earth's gravity, filling up the tank of spacecraft from such a station will significantly bring down refuelling costs. Although this all may sound a bit like science fiction at the moment, SEC's Rule #1 of their design philosophy is: "Nothing is impossible (unless it violates the laws of physics)."
Moon Express, another private company and a contender for the Google Lunar X-Prize, has plans to use the water ice to create the propellant high-test peroxide (HTP)—a concentrated form of hydrogen peroxide, or H202. HTP was used by the Nazis during the Second World War to fuel missiles and the U-Boat 1407. It was then combined with kerosene to fuel the British Black Arrow rocket, which launched the Prospero X-3 satellite in 1971.
However, it is not just water ice that is a desirable lunar commodity. So-called "rare earth elements" are a group of 17 elements of the periodic table that are not often found in concentrated form, making them exceedingly difficult to extract.
"Rare earth elements have a range of important electrical, magnetic and catalytic properties," Ian Crawford, Professor of Planetary Science and Astrobiology at Birkbeck, University of London, told Sen. "They do have enhanced concentrations in some regions of the Moon, but it is not clear if the concentrations would be economic—more exploration is needed."
China is currently the front-runner in the race for mining rare earth elements, with their Jade Rabbit lander successfully making it onto the surface back in December 2013. By the year 2000, China was running 95 per cent of the world's rare earth production—a near monopoly. However, supplies are starting to run low, thanks to their use in everyday objects. One iPhone alone uses eight rare earth elements.
With all of these different companies showing interest for a variety of reasons, who decides where they can mine? "Countries cannot appropriate the Moon as it would be contrary to the 1967 Outer Space Treaty," Professor Crawford told us. "The law does need clarifying with respect to the activities of private companies."
Not all private companies have their sights set on mining the Moon for resources, though. The UK's Lunar Mission One wishes to remain true to scientific research and analyse the surface of the Moon between 20-100 metres to find out what volitiles (elements and compounds with low boiling points, such as nitrogen and ammonia) make up the crust.
A hole will then be drilled to place electronic "memory boxes", bought by supporters of the project, that will serve as time-capsules. Money for developing the project has been raised purely through crowdfunding.
"There is still a lot of scientific exploration of the Moon that needs doing and NASA, and other space agencies such as ESA and JAXA, can and should help with that, in the spirit of the recently formulated Global Exploration Roadmap," added Professor Crawford.
The Global Exploration Roadmap is a set of common goals and objectives that will see different nations' space agencies working together, whilst simultaneously respecting each individual agency’s own ambitions and intents. It began with the International Space Station, and extends to projects involving near-Earth asteroids, Mars and the Moon.
One Step from Earth, by Richard Corfield, is published in Physics World.
