Lunar mining operations

Lunar Mining Operations (LMOs) refer to a set of actions done on the surface of the Moon for extracting resources that are otherwise hard to find on Earth. Although the initial investment cost for any Lunar operation is high, it is estimated that LMOs are one of the most profitable industries for in the 21st century. In 2080, the total net worth of all LMOs is estimated to be $49.3 trillion. The most popular Lunar export is helium-3, an isotope of helium used as fuel for nuclear fusion. It rose to its prominence in the late 2040s, when nuclear fusion became the principal source of energy for most developed nations on Earth. Helium-3 isotopes are traded at around $6,800 per gram in global trade markets, making it one of the most expensive - though profitable - resources.

Though most mining operations are preformed for the extraction of helium-3, rare earth metals are also traded in high volumes, most notably samarium, scandium, and terbium. Rare earth metals are used in more militarized applications compared to helium-3, and as a result Lunar mining sites specializing in rare earth metal mining have become heavily politicized, with trade sanctions and conflicts occurring one after another. One notable example of this is the PAGP backed aggression on JPCC affiliated company Amari Corp's LMO samarium cargo from L01M-OPS (alternatively codenamed LALPHA-JPCC01 by PAGP operatives) en route to the Pacific Ocean on Earth. The operation was, however, masked under the guise of upholding the Outer Space Treaty signed in 1967 by the now defunct United Nations. The politicized and militarized nature of LMOs is theorized to have been the basis of the rise and extensive use of Private Military Contractors both on the moon and around the Earth's orbits in 2050.

Industry
The Lunar mining industry is a complex and developed industry that started in 2035 with completion of the Amari Lunar Base's first open quarry. Lunar Mining Operations are usually comprised of three different sub-operations (sub-ops): extraction, refinement, and shipment. All divisions are intertwined to ensure the delivery of Lunar resources to Earth. Though some LMOs employ contractors to preform certain sub-ops (most notably refinement and shipment), LMOs are generally vertically integrated by their respective companies. A main example is the completely vertically integrated L01M-OPS, a large Lunar base initially built by the Amari Group with its own built-in mining, refining, and shipping operations. Security operations is an optional but vital part of the industry due to the rise of suborbital piracy and the anarchistic nature of extra-terrestrial operations. They are usually contracted by larger corporations as private military contractors.

Mining equipment and edifices are usually assembled on the Moon via in-situ construction methods due to the high launch costs of sending objects onto the Moon. More technical equipment, however, are manufactured and sent from Earth via the Space Elevator or launched via rockets and then assembled on the Moon. The heavy mining equipment Sampson-94 is constructed with materials created both from Earth and on the moon.

Extraction technology
Extraction refers to the surveying and collecting aspect of potentially exploitable mining sites. This includes the construction of an open quarry or a branch mine depending on the resources collected. Due to the Moon's lower gravity, hence lower energy use for relocating Lunar regolith, quarry branches are often used for more general-purpose mines.

Open quarry (Strip mines)
Open quarries are preferred for He-3 extractions since He-3 is concentrated from solar-irradiated Lunar regolith. Quarries are used mainly for their ability to displace large quantities of Lunar regolith. They are usually created using large scale Motorized Bucketwheel Excavators (MoBEs). An example is the Sampson-94, assembled by PAGP affiliated corporation Oberth and Okerford on the Moon for mining firm Nostrand Industries. It is noted for its versatility and power, able to be deconstructed and rebuilt in different areas for different LMOs. It can also be simply moved to another location by driving. It is the heaviest self-powered vehicle ever built at 19,312 tons exerting over 42.1 million pounds of force.

Branch mine
Branch mines are also used on LMOs though they are not ideal for He-3 extractions. They are generally used for rare earth metal extractions such as samarium, terbium, and scandium mines. The metal deposits are first identified by surveying machinery then mined through branches by Deep Mining Equipment (DeMEs). DeMEs are usually much smaller in size compared to MoBEs due to their specialization in mining ore deposits. In a branch mine operation, a borehole is first dug into the Lunar surface above the ore deposit through a DeME borehole drill while simultaneously lowering a mechanized column, the borehole drill is then controlled to excavate the deposit, with ores sent through the column to the surface with built in conveyors. Branch mines are usually 15-200 meters deep. Unlike MoBEs, DeMEs are usually unmanned.

Refining process
The refining process refers to the processes used to transform raw materials and ores into useful resources. Notable examples on the moon include the refinement of helium-3 from surface regolith and the processing of rare earth metals. Precious metals, as well as metals commonly found on Earth, are also mined and processed on the moon, though they are much less profitable due to their relative abundance on Earth.

Helium-3
Helium-3 is a non-radioactive isotope of helium-4 and is found at concentrations of 0.5 to 1.0 ppm on the Moon. It is a very desirable fuel for nuclear fusion due to its reaction products. The high-energy proton emitted from the reaction is comparatively easy to confine and therefore harness for fuel. Rudimentary He-3 mining operations in late 2039 allowed for the relatively easy extraction of the resource compared to Earth based methods. This enabled the subsequent success in harnessing power from sustaining a controlled nuclear fusion in 2043 by PAGP affiliated company Melton Industries.

Unlike other materials mined on the moon, helium-3 is processed directly on the vehicle used to mine it. As helium-3 is a gas, the isotope is stored in large pressurized tanks built into the mining vehicle. Helium-3 mining uses MoBEs to displace and collect Lunar regolith which is subsequently dumped after processing on the vehicles. Processing involves mixing regolith with fluoride compounds to cause a gaseous reaction, with the reactant gas being placed in a large on-vehicle centrifuge that separates the helium from the other gasses. The separated helium is placed into pressurized containers, while the remaining waste gas is recycled for later uses. Unrecyclable materials are dumped into space.

Rare earth metals
During the early stages of LMOs, metal ores with very basic processing were shipped back to Earth where they were processed due to the relatively expensive costs of building more sophisticated refinery facilities. This however, is rendered obsolete with more efficient refinery infrastructure being built to reduce the launch weight of payloads, since unrefined minerals tend to be much heavier than refined minerals. PAGP's Bureau of Extraterrestrial Affairs (BETA) estimates that to break even on a Lunar refinery, roughly 1.4 million tons of rare earth metals have to be processed. Any amount under 1.4 million tons will yield a better return on investment by redirecting refinery operations to contractors or Earth-based operations. As a result, Lunar refineries tend to only belong to very large LMOs. Mid and smaller sized LMOs are usually partnered with LMO contractors specializing in ore refinement.

Samarium
Samarium is a rare earth metal found in large quantities on the surface on the Moon. It is primarily used as neutron absorbent for controlled nuclear fission and Tier-1 nuclear fusion reactors. Samarium is a designated military resource due to its pivotal use in nuclear power generation. The first DeMEs were used to mine samarium due to their relative abundance on the Moon compared to other rare earths. Since 2050, samarium is used extensively in nuclear powered rocket engines used for prolonged space combat.

Scandium
Scandium is an extremely important rare-earth material for creating alloys. Scandium-aluminum-titanium alloys are extremely light and sturdy. It is as strong as titanium, as light as aluminum, and as hard as ceramic. Since both aluminum and titanium are commonly found on the Moon, scandium-aluminum-titanium alloys are commonly manufactured into military grade shields for space combat vehicles to act as a space debris deterrent.

Terbium and Neodymium
Both terbium and neodymium are used to create very powerful permanent magnets used in modular nuclear fusion power systems in plasma propulsion devices.

Shipment to Earth
Shipping Lunar cargo to Earth is a risky and the lengthiest process of all LMO sub-ops. It is usually completed via three steps: launching the Lunar cargo to Earth's orbit away from the Moon's sphere of influence (SOI), deorbiting the cargo by aerobraking using the Earth's atmosphere, and the adjustments of trajectories using powered thrusters while in the Earth's upper atmosphere and parachutes at lower altitudes.

Launching beyond the Moon's SOI
Shipments are launched from the surface of the Moon via freighter launch vehicles to place them in decaying orbits around Earth by leaving the Moon. The freighter's orbit is then readjusted to land back on the Moon. Because of the nonexistent atmosphere on the Moon, significance of the aerodynamics of both the launch vehicle are negated. The low gravity of the Moon makes for extremely heavy launch vehicles without requiring as much fuel as on Earth. Due to the high costs of cargo containers and allowance for high-mass launch vehicles, shipping cargoes are launched 2-3 times every year. Launch vehicle weight varies between 100,000 tons to 400,000 tons. Cargo vessels are non-renewable due to their size and are assembled on the Moon.

Arrival to Earth
Cargo vessels are placed in a decaying orbit around the Earth with a periapsis of around 40,000 meters. Trajectories are adjusted and readjusted using powered RCS thrusters. Due to the limited amount of fuel and the large friction from the Earth's atmosphere, vessels use aerobraking techniques to land on resource collection sites that belong to their respective LMO firms. The resource collection sites are usually located in the ocean. Because these vehicles are unmanned, they are prone to piracy by syndicated crime or terror groups. LMO firms usually employ third private military contractors to ensure the security of these high value assets.