By Mark Sonter, Adjunct Associate Professor, Andy Thomas Centre for Space Resources, The University of Adelaide; and Chairman, Off Earth Resources Pty Ltd

Mining in space, on the moon, on asteroids, on Mars and on the moons of Mars is coming, and probably sooner than you think.

Massive resources in space will enable exponential growth of an off-world econosphere, alongside human expansion into the solar system. The accessible resources of the asteroid belt are guesstimated to be about a millionfold of those accessible on Earth, according to John S. Lewis, solar system space resources expert. 

Jeff Bezos talks of using space resources to build kilometre-scale cities in free space, and of moving heavy industry off-Earth. Elon Musk insists that we must build a city on Mars (but first, the moon) so as to make civilisation multi-planetary, and thus insure against single-planet disasters. The two richest men in the world are focused on humanity’s access to space.

Economic activities in orbit

The space industry worldwide is now earning around US$650 billion per annum, growing at more than 10 per cent compound annual growth rate. This is predicted to exceed $1 trillion by 2030.

The number of satellites in low-Earth orbit is now approximately 12,000, of which about 10,000 are Starlinks. Satellites in geosynchronous (high) orbit total about 590. VAST, AXIOM, Airbus, Orbital Reef and others are planning, and actively building, commercial space stations for space tourism and manufacturing.

All of these assets require fuel for collision avoidance, fleet spacing/station-keeping and altitude control, and ultimate end-of-life disposal. To date, this fuel has all been carried along from launch, but we now see a growing demand for in-orbit refuels to enable extended lifetimes and earning capacities. Orbital refuel is thus emerging as a massive unmet demand.

US company Orbit Fab (founded by Aussie expat Daniel Faber) are planning to fly ‘orbital tankers’ to provide such supplies.

Recent headlines indicate exponential growth of commercial activities in space

Starship Flight Test 12 is coming up (at the time of writing), and will bring further progress towards operational status. Starship is massive, aiming to orbit 200 tonnes, and will ultimately bring cost-to-low-orbit down into the approximately $200 per kilogram range (the figure was roughly $20,000 per kilogram before SpaceX introduced its reusable Falcon 9). This will open up many previously non-viable business cases, including space solar power for beaming to Earth.

A new application has emerged over the past six months or so: Elon Musk has announced plans for a network of one million satellites to operate artificial intelligence data centres in space, to access 24/7 solar power and easy cooling by radiating waste heat to the cold of deep space. The earnings from this will be massive and will pay for his Mars colonisation program.

The logistics and transport route to the moon and Mars

NASA’s Artemis program, alongside other lunar initiatives, will require in-orbit transport nodes/propellant depots. These will facilitate refuelling, as well as transfer of personnel and cargo to transit and lander craft. These logistics nodes will require, at minimum, some hundreds of tonnes of propellant per year to support the planned mass-flow.

Musk’s Mars city (and now moon city) plans will call for much, much more: 2000 tonnes of liquid oxygen and methane to refuel each departing Starship. This has to be either launched from Earth in ‘Tanker’ Starships (10 for each departing ship), or alternatively imported from production facilities in deep space.

Defence requirements

The US Space Force has repeatedly cited its urgent need for supply of propellants in cislunar (i.e., above geostationary orbit) space, to enable manoeuvrability for agile operations.

There is thus an emerging high-value market for fuels in space, predicted to reach US$5–20 billion per annum by 2030, and there are highly prospective potential sources in space of precursor feedstock for manufacture of these commodities.

As such, resources in space are needed for supply of propellant and metal in space, and for more exotic high-value products for export to Earth.

The moon

There will certainly be civil engineering works leading to development of a manned NASA base on the moon by 2030 – developing landing pads, roads and base facilities. These will be both robotic and human-in-the-local-loop. We should expect to see the first mining operations in the same timeframe.

The lunar regolith has been ‘gardened’ by meteorite impacts, and has been implanted with solar wind light-atom volatiles over billions of years. Heating will release these volatiles – the most valuable being Helium-3, worth $20 million per kilogram. American company Interlune, founded by Apollo program astronaut Harrison Schmitt, has signed contracts to deliver Helium-3 to terrestrial customers starting in 2028, and is well-advanced in the engineering of its ground-truthing digger-devolatilisation trial miner to achieve this.

Lunar regoliths have also been shown to generate free oxygen and metal when subjected to molten regolith electrolysis. Blue Origin subsidiary Blue Alchemist has demonstrated the manufacture of solar cells from molten lunar regolith, with the aim being to develop a robotic factory to make solar panels at scale on the lunar surface, for provision of power.

Any separated commodity made available for sale on the lunar surface will be in competition against Earth supply, the landed cost of which will be around $100,000 per kilogram (this being SpaceX’s quoted price for delivery to the lunar surface once Starship is operational).

The discovery of water ice in permanently shadowed craters around the lunar south pole has made that area a prime target and potential location for ice mining, and thus the production of oxygen and hydrogen for fuel. There will be major challenges because the lunar regolith is very abrasive and compacted, and thus likely quite difficult to mine, made more difficult in these craters by the intense cold – around 40 degrees Kelvin.

Rare earth elements

Although present in KREEP (potassium, rare earth elements and phosphate) mineralisations, these are quite low grade, and are not really viable for supply to Earth. This is because ‘the first thing to learn about rare earths is that they are not rare’, being present in mineral sand deposits worldwide and also very widespread in hard-rock deposits. This means that KREEP will be useful in a mature lunar economy, but is not a realistic source for terrestrial supply.

Asteroidal reduced metal

There are good reasons to search the moon for the presence of strewn fields of metal fragments from the impact of metallic asteroids. This was first posited by Dennis Wingo in his book Moonrush: Improving Life on Earth with the Moon’s Resources, and his research has identified several such deposits.

The near-Earth asteroids

We have now discovered about 40,000 near-Earth asteroids (NEAs), of which about 50 per cent are of a diameter greater than 100 metres metres and thus potentially big enough to be interesting as resource objects. Alongside this, about 20 per cent are intermittently more accessible than the moon. The appearance and composition of NEAs is bimodal, with about 60 per cent being carbonaceous C and D types, and very dark; about 40 per cent are bright, silicaceous and metallic S and M types.

The C and D types are composed of clays, organic carbon compounds, metal carbonate salts, and magnetite (from assays of spectrally analogous meteorites, and from samples returned from Ryugu by Japan Aerospace Exploration Agency’s (JAXA’s) Hayabusa2 Mission; and from Bennu by NASA’s and The University of Arizona Lunar and Planetary Laboratory’s OSIRIS-REx Mission).

The S types are composed of simple silicates (olivine and pyroxene, again, per spectrally analogous meteorite assays, and samples from Itokawa via JAXA’s Hayabusa Mission), with proportions of reduced nickel–iron metal ranging from zero to very high, for the M types.

The C- and D-type NEAs are very tempting as possible resource objects because of the apparent ease of extraction of water from the clays, and of hydrocarbons from the carbonaceous matrix. They are subject to detailed ongoing study in this regard by our own group, Off Earth Resources Pty Ltd, and by Karman+ in the United States, among others.

The S- and M-type asteroids offer easy-to-recover reduced metal, which is directly useful for making sheets and structural beams for in-space construction. They also contain enhanced levels of platinum-group metals at around 20–100 parts per million, which has gained wide headline notoriety and hyperbolic claims of valuations in the trillions-of-dollars range. 

These grades are high compared with terrestrial mines, but the challenges of extraction robotically in space cannot be underestimated, and will probably only be successful in the context of a mature space resources processing industry. Nevertheless, this is the business plan of AstroForge, another US startup.

The moons of Mars

The moons of Mars are spectrally very similar to the 
C- and D-type asteroids, and are thought to have the same mineralogy. JAXA’s Martian Moons eXploration Mission will launch late this year, and is intended to bring back Phobos surface samples. Our own company has taken a deep dive into the prospectivity of Deimos and has developed conceptual plans for mining it.

Timeline to commercial access

The timeline to lunar mining operations is now approximately 2030; however, robotic civil engineering will probably start as early as 2027.

The timeline to first mining missions to access the NEAs can be similar. Off Earth Resources Pty Ltd in-house studies have indicated that a simple trial mining/demonstration mission, returning several tonnes of regolith from a selected highly accessible target, can be done for around $150–200 million – surprisingly low capex, and low-risk, using off-the-shelf equipment and services, and having a fast return. We could conceivably see such a mission launch by 2030, with windfall profit on the first flight.

The commercial opportunities

The value of commodities in orbit (metal for construction, or propellant for spacecraft refuel) is set, at minimum, by the cost of launching from Earth. The present cost to low-Earth orbit depends on orbit details, but is set by Falcon 9 list prices: for ‘rideshare’, around $6500 per kilogram; for dedicated launches, somewhere in the $1500–2000 per kilogram range. As you go to higher orbits, the price rises due to the greater difficulty of access: price to geostationary on a dedicated Falcon is around $20,000 per kilogram. When Starship becomes operational, these prices will drop gradually by a factor of five or so.

The opportunity for space-sourced commodity supply is twofold. First, to beat these delivery prices because of the mass-multiplication factor inherent in mining, and the easier supply route from bodies in free space. Second, to bypass the mass-flow chokepoints of limited terrestrial launch sites and flight cadence, alongside environmental, logistical, supply, and political constraints.

Thus, robotic miner facilities, once set up, can supply several hundred times its own mass back, per year, of high-value commodity, to purchasers in high-Earth orbit, thus competing successfully against an Earth launch even as Earth launch costs drop. 

About the author
Mark Sonter is an internationally recognised thought leader and subject matter expert in asteroid resource studies. He has 45 years of experience in radiation protection, safety, occupational hygiene, and chemicals management in uranium, mineral sands, and rare earths mining and processing, and in management of naturally occurring radioactive material in the oil and gas industry. He has consulted on many projects in Australia and overseas since 1995. Sonter is a Co-founder of Off Earth Resources Pty Ltd. He holds an Adjunct Associate Professor position with The University of Adelaide in the Andy Thomas Centre for Space Resources. Sonter’s consultancy companies are Radiation Advice & Solutions Pty Ltd and Asteroid Enterprises Pty Ltd. He holds a Master of Applied Science (Medical Physics) from Queensland University of Technology, a Graduate Diploma in Occupational Hazards Management, and a Research (Honours) Master in Science from the University of Wollongong.