Key to sustaining a long-term presence on Mars will be the extraction of resources supporting local manufacture and use. In the extreme cold and dusty conditions, electronic and mechanical equipment can be expected to break down at an alarming rate.
Given the high cost to ship replacement parts to the Red Planet, not to mention the months-to-years-long shipping time, certain resources will be mined and refined to fabricate those parts instead.
So, let's examine some of the most likely minerals to be mined there, what they will be used for, the mining and technology needed to extract them, and the processing required to obtain useful constituents. This list isn't exhaustive, but it gives us an idea about the effort needed to maintain a continuous human presence there.
Likely Mineral Candidates for Mining on Mars Ice. Water will be needed for the essential functions of drinking, cooking, bathing and growing crops. Hydrogen and oxygen electrolyzed from water will be used for rocket fuel. They will also be vital for portable energy, a host of industrial chemical processes, air supply and metallurgy.
Perchlorates. These highly toxic salt anions are globally present in Martian soils, which will need to be decontaminated to be useful for growing crops. Perchlorate salts of certain metals are used in explosives and solid booster rocket fuel here on Earth.
What about rare earth elements (REEs)? After all, they're being prospected in Crimson Lucre and Red Dragon. They are a collection of seventeen metals from the periodic table—yttrium and the lanthanide series. Unlike their name implies, they are common constituents of Earth's crust. But they are rarely concentrated into ore deposits that are economical to mine. Once mined, these minerals are refined and converted to oxides for storage and treatment, then reduced to their metallic form(s) for incorporation into finished products.
REEs are critical components of computers, cellphones, batteries, and military technology. Their uses are as diverse as doping agents in transistors and in lasing chambers in lasers, small powerful magnets in electronics, and as catalysts for a host of chemical reactions. China leads the world in REE consumption. The United States ranks third. While US production has risen with the rising commodity prices, China still mines ninety percent of the Earth's supply.
Copper. Mars will run on electricity for heating and lighting, to power environmental equipment, operate computers and communications equipment, and operate vehicles. Copper wire will transmit electricity to fixed facilities inside and outside bases. Transportation will be powered by electrical fuel cells.
Electric motors will be ubiquitous, running water pumps, air circulators, hydraulic system pumps and propelling transportation and heavy machinery.
Silica. Sand? Really? Silica is an important resource on Earth: used to make glass for windows, beverage containers and electrical insulators. Fiberglass products range from bathroom fixtures to roofing material, boat hulls to auto bodies. Fiber optic lines are critical internet infrastructure.
The melting point of silica is high (3,110 degrees F). Large-scale high temperature furnaces would place an enormous strain on the limited power supply on Mars. But small batches will be melted and doped with carbon, resulting in carbon dioxide and silicon. Transistors will be fabricated from this raw silicon with some additional processing. It will be critical for maintaining electronic equipment when spare parts are otherwise months to years away.
Mining Methods on Earth Water is abundant and accessible on the Blue Planet. Rather than mining ice, it is manufactured, primarily for use in food processing or for consumption.
Perchlorates are most often obtained by industrial chemical processes that bond four oxygen atoms to one chlorine atom. The resulting molecule dissociates in water to perchloric acid. When reacted with metallic bases useful—though toxic—perchlorate salts result.
REEs are found in a class of igneous minerals known as alkaline rocks. They form under certain magma conditions associated with crustal subduction zones that allow these less-common elements to concentrate.
They also exist in placer (sandy or gravelly sedimentary deposits)where formation favored heavier material selectively settling out. REEs are often associated with gold placer deposits.
Mined in an open pit, the rock is crushed, and then subjected to a series of chemical baths that leach out and precipitate the various REE oxides. Because of China's market manipulation, they are the only class of minerals considered in this article that could be economically feasible to ship back to Earth from Mars.
Copper porphyry deposits are created by hydrothermal processes close to subduction zone magmas. Chalcocites are copper sulfate ores formed as veins within magmas. The largest open pit mines in the world extract copper of either geological origin.
Silica is mined from huge sand beds or from large quartz formations. Granite and other silica-based minerals constitute planetary crustal materials. Sand is a byproduct of crustal weathering and erosion. Quartz veins, which can contain enormous glass-clear crystals, is hydrothermal in origin. Superheated water will dissolve quartz within granite formations (batholiths and plutons) and redeposit it in underground fissures. Some of these veins are so large and numerous that they can be mined in open pits.
Mining Adaptations for Mars Mars is a tough place to operate heavy machinery. Most places on the surface experience nighttime winter temperatures at or below minus 150 degrees F. Diesel fuel begins to gel at plus 15 degrees F. Hydraulic fluid, the non-compressible liquid that enables hydraulic equipment to lift and move massive loads, freezes at minus 10 degrees F. The cold-tolerant hydraulic fluid used on the space shuttle landing gear had an operating range of minus 70 to plus 700 degrees F. Properly insulating and heating pumps, reservoirs, lines and cylinders will be critical for operating mining machinery on Mars.
Mars's atmospheric pressure is one-one-hundredth that of Earth, plus there is no free oxygen. This poses a dual challenge for mining equipment. Whatever power source is used, the machine will have to carry its own oxygen supply, whether for an internal combustion engine (ICE), or for an operator environment inside a sealed cab.
Internal combustion on Mars will be a viable option, provided the fuel is a gas or liquid down to minus 150 degrees F, and tanked oxygen is supplied to burn it. Methane will not be readily available, as there are no known subterranean sources like hereon Earth. But hydrogen and oxygen can be from electrolyzed from water. Both are gases within the frigid temperature range, enabling a simple fuel injection system. The excess heat could help maintain an operating temperature for hydraulic fluid.
Mars will be much too cold for batteries to function outdoors. Rather, when not in use, an ICE must be plugged in to a power source—to warm the lubricant reservoir preventing the fluids from freezing and to turn over the ignition to restart the machine.
A hydrogen fuel cell would employ the same fuel and oxidizer as an ICE but would run electric motors for transport and the hydraulic pump. A lubricant reservoir would not be needed, making an external power source less important.
The extreme cold and lack of atmosphere would require a sealed climate-controlled cab for the operator. But given the semiautonomous nature of modern construction equipment here on Earth, Mars mining machinery will also be semi-autonomous as well. A nearby building would house drivers who could remotely operate the mining equipment if trouble developed. Haul trucks might not need any assistance at all, given the exact same route would be taken from loading point to dumping point and back.
Water. Water ice will be mined on Mars using much the same methods used for hard rock mining on Earth. Hellas Planitia, the massive impact crater that serves as the setting for Crimson Lucre and Red Dragon, contains the largest concentration of glaciers outside the poles, and with warmer overall temperatures. But ice, buried under layers of dust, persists in many locations around Mars. Most water and ice is heavily contaminated with perchlorates and will have to be purified before it can be used, or processed into hydrogen and oxygen. Equipment needed will be rock drills, explosives, excavators, loaders and haul trucks. Distillation or other means will be required for water purification.
Perchlorates. Because perchlorates are water soluble salts, they will be derived from two sources: byproducts of water purification, and leached from regolith or windblown deposits of dust and sand. Material will be excavated and treated to a water bath within a pressurized environment, to prevent the water from boiling away and/or freezing. Purifying the resultant contaminated water will yield perchlorate salts. One byproduct will be decontaminated soil for growing crops. Primary equipment needed would be excavators, loaders, haul trucks, and self-contained pressurized reaction vessels to isolate or create desirable salt species.
REEs. No known deposits have been identified on Mars. But alkaline rock minerals no doubt exist within some of the volcanic provinces. Hellas Planitia undoubtedly was a magma sea after the impact that created it. It, and other large impact craters might be reasonable places to prospect for alkaline rock formations as well.
Mining for REEs will employ open pit surface mines. Rock drills, explosives, excavators, loaders, rock crushers and haul trucks will be required. An enclosed pressurized environment will be needed for the water-based chemical processing to produce the oxides.
Copper. The lack of tectonic processes on Mars may restrict copper to chalcocite veins within volcanic regions. The hydrothermal conditions that lead to Earth's massive porphyry copper deposits were likely rare, if ever present. This will make it difficult to find a concentration of ore-bearing veins to mine.
It could take years of prospecting to find sites suitable for open pit mines, delaying Mars's self-sufficiency in this metal. Colonies will have to rely on copper from Earth and strict recycling regimens for the first several decades.
Silica. The same methods and equipment for surface mining regolith for perchlorate harvesting can be applied to silica. It's conceivable the same deposits will source both minerals. Silica sand beds will be available in alluvial fans and sedimentary deposits downstream of granite-bearing highlands. Excavators, loaders and haul trucks will be the primary equipment needed.
As noted earlier, the high temperatures required to refine silicon from silica may restrict processing to small, boutique batches for fabricating transistors. Either lasers, or a hydrogen/oxygen torch could provide the necessary heat source. Once fusion power comes to Mars (I predicted in my March 2022 edition that won't occur until well after 2050), high energy smelting and refining processes will be able to scale up. Until then, glass will be a relatively rare material.
There you have it. A high-level look at the economic foundation of the first long-term colony on Mars. If you're a geologist, cold weather hydraulic equipment mechanic or operator, industrial chemist, mechanical engineer or farmer(everyone's got to eat, right?) get your application in today. Fifteen years from now might be too late.
For Further Readinghttps://en.wikipedia.org/wiki/Perchlorate#/https://en.wikipedia.org/wiki/Polyethylenehttps://en.wikipedia.org/wiki/Polypropylenehttps://en.wikipedia.org/wiki/Carbon_fibershttps://geology.com/articles/rare-earth-elements/https://geology.com/usgs/ree-geology/https://en.wikipedia.org/wiki/Porphyry_copper_deposit
