Long Hab

Long Hab is a long, deep habitat with a vaulted roof. Like all habs in this mission architecture, it has plenty of natural light and big outdoor views. Its views are achieved with mirrors and lenses, so that radiation is kept low and the structural challenges of large windows are avoided.

Enough equipment, crew, and knowledge have built up for Long Hab to be a big step up from First Hab. It is 200 m long, 30 m wide, with variable depth of 30 to 50 m from the floor to where the walls meet the roof, and the vaulted ceiling is 15 m high.

Tele-operation of the robots building Long Hab is done by the crew of First Hab with support by the crew of Crossroads. Little tele-operation is done from Earth for construction. It is also uncommon for astronauts to work outside on construction, instead they do most things remotely through the robots. When they go out, they put pressurized cabs on the rovers and wear only flight suits, not proper space suits. Space suits are very restrictive, uncomfortable, and clumsy, they are used only when necessary (and occasionally just to go for a walk outside).

Construction Process

• In-situ construction materials and techniques have developed enough that nothing structural is brought from Earth for Long Hab, and even some systems installations are made of local materials.
• Excavation methods have matured enough that vertical walls of great height, deep undercuts, and tunnels of 50 or 60 meters are not a problem.

• • Blasting is used to make shaped pits and channels. Their sides are then made smooth and vertical by paring down lumps with heat-based cutting methods. The colony now has many such tools on a range of scales. Hollow bits are boarded over and packed with regolith.
  • Ripper and jack-hammer attachments on the arms of heavy-duty construction rovers still do rough shaping of recesses and undercuts. After that, specialized liquid-cooled saw blades and drill bits allow cuts to be made and holes to be drilled. Heat from friction would build up in the vacuum environment and make blades and bits seize if they weren’t cooled. The bulk of the cooling systems make the them thick, they can’t cut or drill anything narrower than 3 cm across.

• The arches that form the vaulted roof are made of blocks from the first full MIP stations – melt-in-place stations, that evolved from earlier processes of that kind. There are also now many graphite molds, and molten regolith is produced in bulk for them, and for pouring into forms for large pieces. The roof is reinforced with basalt fiber cables from new production facilities making basalt fiber products on-site. Good basalt feedstock for the process is brought by LNCs returning from sorties where they had access to it.

Hab Architecture

The astronauts don’t get to spend much time outside, and they are never truly outside. When on the open surface they are surrounded by beautiful desolation that can’t fill in for the outdoors on Earth. Their indoors has to be their outdoors too. This is one reason why it is so important to make the habs as huge as possible from the outset. It is a matter of emotional health, and that becomes more important with each passing month of a person’s stay.

The habs are also all huge because many things about regulating an environment in space become easier with size: thermal regulation, air recycling, air quality, noise control, and everything having to do with creating and balancing an ecosystem, from mold not growing on every surface where it has the slightest chance, to there simply being enough space for a complex set of organisms to coexist in something resembling harmony.

Thanks to the materials the habs are built from, and the way they are melded together, surfaces are never quite straight or flat and corners are soft. Once the molten regolith parged over the walls and ceilings has cooled into a single glassy surface, it will naturally have variations in tone and texture, and many simple things can help that along to accentuate the richness of the final patina. Not only is the building technique the best way to make use of the local materials, it is the best way to create a space that feels like you are in nature, though you aren’t. This will be important to the residents.

Functional Features

• Light tubes terminating in lenses – similar to the light tubes shown on the initial model of First Hab, these tubes funnel in a large amount of sun, and can do so most of the time at Inukshuk’s location. In this version, the lens at the mouth inside the hab disperses the sun over a wide enough area for it to have the intensity of sun near sunset, with the spectrum of sun at noon.
• Sky-like sections – A thin layer of molten aluminum is sputtered over these sections of the vaulted ceiling, leaving a surface that creates scattered, mottled reflections. This creates a sense of space above and distributes light more evenly. This is done in the sections with the light tubes, of which there are three along the length of the hab, interspersed with Earth-view sections.
• Earth View Sections – There are four of these sections, and each has a large view of the Earth set up. Lenses are used to funnel that view through small gaps in the regolith overlay protecting the hab from radiation. Specifically, concave mirrors are placed to reflect the view of Earth through those lenses, which pass it to other large mirrors placed against the slope of the ceiling opposite. This way, there is a bright, clear view of the Earth visible in those mirrors, magnified by about a factor of 3. Because the Moon is tidally locked with the Earth, the Earth only moves around in its sky within a small circle about 15° across. At the colony site, the Earth is below the horizon for part of each month. When it is in the sky though, the residents have a gorgeous view.
• Passive thermal control – A narrow channel down the center of the hab reaches bedrock. The bottom of the deepest section does too. Heat diffuses very slowly through regolith. It moves much faster through rock, and rock is also decent thermal mass. The surface area of the hab that is fused with bedrock is tailored such that the incoming heat from sunlight balances the heat moving outwards through that rock. Well-placed fans that keep the air circulating well is all that is needed to maintain a very steady, comfortable temperature.
• Tunnel to First Hab – About 40 m separates First Hab and Long Hab. The two are connected by a small tunnel near the surface, actually a channel that was cut and then covered over. One end has an emergency door that will slam shut if there is a big change in air pressure on either side, just in case of an extremely unlikely disaster. Stored air can compensate for pretty big leaks long enough for an emergency patch to be made, or for people to take shelter in the airlocks if it’s really bad. Only extremely rapid decompression would cause the door to close, in which case whoever is on the other side is out of luck.
• The Larder, the Fridge, and the Freezer – Branching off from this tunnel are three pits with silos inside them. The silos contain a normal atmosphere and are entered through insulated doors. Sunlight never reaches the inside of these pits. They were dug such that once the silos were set down inside them, about a meter of space remained between the sides of the pit and their walls, and they sit on stilts. On top of their domes are radiator units. It’s very easy to keep these silos cold. One is kept cool, for long-term storage of things like potatoes, onions, and apples. One is cold, for storage of perishables like cheese and fruit. One is below freezing, for meat and fish, and for freezing the ice packs for the coolers widely used elsewhere in the habs. There are often reasons to store other things at one of these temperatures, the silos store a mish-mash of items. Each silo is 8 m across and 12 m tall. At first they are mostly empty, they are sized in consideration of future growth, especially for the Greenhouses coming online.

Layout Features

• Gardens – Each sky section is filled with as much vegetation as possible. About half is grown hydroponically, the other half is grown in soil, as that soil slowly accumulates. The work done at the EESS on beneficiating regolith into fertile soil has had success. The EESS sends back a couple of tons of the stuff and the recipe for making it. In place of organic matter to fluff it so it’s properly aerated, they mix in perlite made on-site by foaming molten rock with compressed air. This soil is placed in several long, narrow beds, where the crew plant a variety of test plants, including a few bushes. In time, all the designated beds and planters are filled with soil, which is then slowly made deeper. As it is the soil that is the key to creating a true ecosystem, and those gardens that give the feeling of the presence of nature, the large ones at the bottom of the sky sections are planted with the widest possible range of plants. Each one has two or three small fruit trees, a number of bushes, vines climbing the walls, vegetable beds, flower and grass beds, and cacti.
• Pond – The pool water (see Health, below) is pumped to a pond in one of the sky sections, that is planted with a range of aquatic plants. It is important for ecosystem creation to figure out how to purify water with natural processes. It takes a while before the crew manages to get the pond environment going. For a long time the pool water is mostly purified with filters and ultraviolet light disinfection systems. Slowly the pond becomes healthy and takes over the job.
• Lunar parkour – The exertion of normal activities on Earth is absent on the Moon, if they are done in the same way. Designing the hab interior to take account of this allows residents to move in a way that is more efficient, more engaging, and healthier. Instead of stairs, tubes are used to move between floors, where you grab the sides and haul yourself up. With practise, residents learn to do this so fast it is a sort of vertical running. People often jump between floors as well. It becomes a passtime to find new and exciting ways to move around the habs by bouncing off walls, swinging from things, and jumping great distances. Things are placed to create opportunities for this. Each level of the hab is also high, 4 to 5 m, to give people headroom even though a normal moon walk has a pretty high bounce in it.

Health Facilities

• Swimming Pool – With the ice mines producing lots of water, this is a full olympic sized pool with a deep end deep enough for high-diving. Swimming is an important conditioning exercise for residents – it loads their muscles in a way that is hard to achieve outside the water, making them work as hard as they have to on Earth to do the same thing, a consistent load that can be gentle or quite demanding. It is a central part of their cardio and muscle-building routines.
• Manual centrifuge – this looks sort of like a wide bicycle wheel on its side whose axle is connected to a platform where people can spin the wheel using pure muscle power. It takes a while to get going but can then be maintained fairly easily at an RPM that imitates 1 gravity of force for the people on the rim of the wheel. Spending time frequently in this simulated gravity is important for the health of the residents – for their circulatory systems, and fluid distribution in their bodies, and the health of their bones. It’s unknown how much time a person would need to spend in this simulated gravity. Doing exercise on it would maximize its benefit to bone and circulatory health. The exercise of pushing the wheel is also beneficial. In this case it is designed to have a social element in that some push while others ride, a method suitable for something that takes an hour or so. A motor can also be used to turn the wheel. If in the long term other health effects due to low gravity can only be corrected by more extended time in simulated gravity, larger centrifuges designed for longer periods on the wheel will be needed. The body may need extended time there for more subtle corrections to the effects of low gravity. If more than 2 or 3 hours a day is needed long-term, more complex centrifuges than this will be needed.
• Lunar gym – The gym area is the full height of Long Hab’s tallest section, 50 m. Its floor is so heavily padded that even if someone jumps from the very top if it, they will land unharmed. The foam used is stiff enough that in the low gravity it can be walked over fairly normally, but yields sufficiently to absorb the energy of a jump from 50 m. Sections of the floor are trampolines, for rebounding back up over that distance. The padded walls are covered with small ledges and recesses for hand and foot holds. There are a bunch of ropes and nets hanging from ceiling to floor. The reason for all this is that in lunar gravity to get a decent workout, and to load as many bones and muscles as possible, the thing to do is climb. To put your skeleton through the forces it handles on Earth, the best thing is to jump high. It’s also pretty fun to be able to jump up and down from so high safely. The residents quickly start inventing vertically oriented sports and games.

Infrastructure Upgrades

• The solar panel masts are expanded to provide more power, more of the time. They are made taller and wider, and the panels are moved up the mast, so they are all on the top half.
• A large rectenna grid is set up to receive power beamed from Crossroads and Sagan when they are in range. The skyhook solar wings are always in the sun. To be well aligned with the skyhook’s transmitters, the rectenna disc has to be able to both rotate and tilt. It is on an axle supported by towers that turn on tracks around a circular base. Grid-type rectennas are very light, in the lunar environment it is not hard to make this unit 200 m on a side. The transmitters on the skyhooks are much larger again. After this point, beamed power provides a large fraction of the colony’s needs.
• Large unpressurized hangars are built. They are half-pipe shapes on a levelled platform that has been covered with a slab of fused regolith. A shallow overlay of about 30 cm of powder regolith protects them from most radiation, and the heat of the sun. The interior temperature stabilizes at the average ground temperature of about -20 °C, which is a perfectly comfortable environment for machinery. This provides lots of space for manufacturing activities – dust free, stable temperatures, and free of radiation (except for cosmic radiation). A covered pit within each hangar provides some space for processes that require protection from cosmic radiation, as well, and storage space.
• There are also similar hangars that hold a very thin atmosphere of about 5% Earth’s atmosphere. These are for processes that need to shed a lot of heat. Basalt fiber production is the best example. Even a very thin atmosphere can transmit heat as well as a full atmosphere, the trick is to circulate it so that the heat picked up is quickly transferred to a heat sink, and from there can be radiated away. The stone slab floor has pipes that circulate heat to radiators in a trench just outside the hangar, along one side of it.
• In both these cases, these structures are much like hangars on Earth in that they have large spans uninterrupted by any columns or other internal divisions, very large doors, and are covered by an arched roof.

First Greenhouse

The greenhouse is divided into two halves, making it more like two connected greenhouses. When it is night in one half, it is day in the other. This way, the colony’s access to constant sun can be used to double output. To do this, the outlet of the light tube that delivers sun to the interior of the greenhouse pours that light onto a slanted mirror that bounces it onto the aluminum-coated greenhouse roof, which scatters it over the plants on the walls and floor. The light is spread enough to dilute it for maximum yield of the widest range of plants – even plants that like full sun are happy with sun that is about 2/3 the strength of sunlight on Earth, and sun on the Moon is about 30% stronger than that. That spreading also makes it only very weakly directional, it is more like sun through frosted glass.

The greenhouse is two round pits surrounded by berms, with sloping walls and circular floors. They are each covered by a shallow, solid stone dome held down by basalt cables, which has a few meters of regolith on top. These domes overlap by about a sixth of their diameter, and in the middle of that overlap is the light tube with its big parabolic mirror on top funneling a ton of light down into the greenhouse as it tracks the sun. A passage between the two sides inside the structure holds the mirror that bounces that light to the domes. That mirror holds position for 12 hours, then it rotates and holds position for another 12 hours. Each dome is 100 m across. From floor to the top of the slope is a height of 20 m, and the dome rises 20 m more.

Below the level of the mirror, the passage widens, and a hall off one side terminates in a work room. That workroom is connected to a hall going to Long Hab.

The two halves of the greenhouse have very different projects. One side is focused on food crops, including raising insect crops for protein. The other side is focused on ecosystem research – searching for the combination of plants and animals that will establish a network of relationships that support each other, so the ecosystem is stable without intervention. Because the populations inside that half need to be monitored carefully, it is isolated from the other side, as much as possible. The mirror setup is built to remain sealed from the other side when it turns, the passage can only be reached by going through two doors with tight seals around them. It doesn’t stop transmission of micro-organisms or spores, but it makes the picture of the dynamics within that greenhouse easier to see. A few animals have already been successfully brought to the Moon – earthworms, a few pollinating insects, small fish. This greenhouse gets a much larger set.

As the atmosphere of the colony is custom designed, a higher proportion of carbon dioxide is established in it, to accentuate plant growth. It is set at 0.2%, or 2000 ppm, 5 times the current level on Earth. This is low enough to have no impact on the health of the crew, and is a feast for the plants.

Research into Basic Industry

Working with molten regolith of various sorts has been developed pretty far. They can make fabric and rope out of basalt, and a wide range of stone and glassy objects[?] and materials, some reinforced with glass fibers. These materials fulfill almost all structural needs well. The priority at this point is to develop local processes for producing the other building blocks of an industrial society out of local materials. Some things will take time, certain things can make a big difference in the short term.

Technically speaking, a glass is any solid with an amorphous structure at the molecular level, which is to say, not crystalline. Many of the materials made before this out of molten regolith will have that quality, and quite possibly be very strong for that reason. It has been theorized that the ability to produce glassy materials in a completely anhydrous environment – that is, devoid of water – will mean the resulting glasses are far stronger than glass on Earth. Earthly glass is full of microscopic flaws due to its trace water content. If a glass with a higher melting point is spun into fiber, and those fibers are mixed or pressed into a glass with a lower melting point, the composites produced could have good strength in tension, compression, and bending.

• Metal – The colony has 3d printers that create complex solid objects out of metal powders. Those powders are shipped from Earth. With the mining of high-purity iron ore in the peaks of a particular crater (mixed with nickel, a touch of cobalt and traces of other metals typical of metal asteroids) the colony works on smelters to purify that ore in bulk into each of its component metals. Dust roaster units, that super-heat regolith into plasma and separate the component metals by electromagnetic deflection, are also brought from Earth and deployed. Use of metal is avoided unless there is no good alternative. The amounts the colony needs at this point are easily supplied from Earth, but this research is important for the future. Especially important is aluminum for mirrors and electrical wire, and silicon for solar cells and transistors.
• Carbon – On the Moon, you can’t have too much carbon. In preparation for the retrieval of carbonaceous asteroids that will provide carbon, research is done on processes adapted to the lunar environment to create the following products:

• • Topsoil – is about 8% carbon, bound in organic molecules. To create enough soil to create a true ecosystem will take many kilotons of carbon. That carbon must be combined with hydrogen and oxygen to form complex organic molecules, such as sugars. Sugars get eaten by micro-organisms and animals, converted to other organic molecules, and it is at that point the carbon becomes part of the biosphere. Reactors that will form sugars from water and carbon minerals are developed. Alternatively, a special greenhouse with an atmosphere as high in carbon dioxide as the hardiest, most carbon-dioxide-loving plant will thrive in could be used to fix carbon in organic molecules.
  • Polymers – Zylon, the material proposed for the skyhook cables, is mostly carbon. Many plastics contain carbon.
  • Steel – is up to 2% carbon. Plain iron is not very strong. Although iron is very common in many parts of the Moon and is by far the easies metal to purify there, unless carbon is added to it, its usefulness is limited. Although lunar glass composites can be used for many structural applications, and mass on the Moon is not much of an issue, being able to make certain components out of steel will probably be helpful.
  • Explosives – Digging is way too slow and difficult on the Moon. In a place with no environment to damage, why dig? If you can blast, you should blast. Just remember there is no air to slow down the debris, so best to use many small charges to limit the range and velocity of the flying shrapnel caused by explosions. Having plenty of local explosives makes things easier.
  • Chemical processes – carbothermal reactors can be used to extract pure metals from metal oxides. On the Moon, it would be attractive to use this process to purify silicon, magnesium, calcium, and aluminium. Usually, pure carbon is heated with a metal oxide to a few hundred degrees Celsius, and carbon monoxide or carbon dioxide is produced along with the metal. Carbon is so precious, it would be critical to capture and reprocess virtually all of the gases produced.

• Silicone – is a class of polymers that in many cases do not include carbon in their formula. Production of a range of silicones in-situ would mean lubricants, seals, sealants, rubbers, and plastics could be produced locally, without using precious carbon.
• Transparent Glass – Creating a sense of open space on the Moon will require a very great deal of clear glass. The polar hab designs are alright, but living without sky or being able to look outside is a big sacrifice. The Holy Grail is glass domes over entire craters. Though artificial light will still be needed to get plant life through the long night, in the day plants can bask under real sunlight in a much more natural way under such a dome. People can feel the sun on their skin, and look up to see the real sky (though not a blue sky). Bulk processes to produce it in industrial quantities are needed.
• Sapphire and Quartz – Both of these crystals have very low thermal expansion coefficients, can withstand high temperatures, are chemically stable, strong, and highly transparent over a wide spectrum. Once alumina and silica – their normal, non-crystal forms – can be refined out of the regolith in quantity, reactors to produce large crystals of them will be set up. On Earth today, large items made of quartz and sapphire are available. Further evolution of that technology enables massive lenses, panes, domes, and tubes of sapphire or quartz. Because constant intense sun is perhaps the Moon’s greatest natural resource, such items will be used to do many things that on Earth are accomplished in other ways. Anything that can be done with heat, is probably best done with heat on the Moon. Better to reduce use of chemical processes, as the Moon is almost completely devoid of most common catalysts and reagents.

Missions Around the Moon

The LNCs now have much greater liberty to make sorties to anywhere on the Moon, as the ice mines provide plenty of fuel and the skyhooks make fuel requirements very low. The combined complement of almost 300 people on the Moon by the end of this phase provides plenty of skilled operators for these sorties.

• As mentioned above, surveys uncover deposits of high-grade iron ore embedded in the central peaks of a few craters. They are the remains of the asteroids that impacted there, ones that came in slowly enough, at the right angle, to not have vaporized completely. The most promising case is selected for mining. After study from the surface is completed, aggressive blasting is begun. Unlike the careful, minimal blasting done during excavation in regolith, in this case, small numbers of deep bores are bored, and packed with plenty of explosives, with the aim of advancing into the mountains quickly. The LNCs transport back loads of ore to Inukshuk.
• A number of large lava tubes are discovered. They are explored in detail. In the one with the large skylight, a small mobile hab is delivered and lowered into it, so a small research team can stay for longer periods and have more tools at their disposal. samples are extracted and returned to Inukshuk for study.
• A suitable crater with a smooth bowl shape is selected on the Moon’s far side, and work begins to convert it to a radio telescope along the lines of Arecibo. It is 3 km across.
• The volcanic region around Aristarchus Crater is explored.
• Anchor towers are built on either side of Shackleton Crater, cables are strung between them, and a specially designed exploration rover travels on this cable back and forth, using the slack to get close to the deep dark interior and examine it in detail without touching it.
• Seismic sensors are set up around the Moon
• Lalande Crater is surveyed and examined in detail in preparation for construction there. Blasting is done in several areas there, first in exploration, and later to remove materials in key areas while there are still no structures that could be damaged by the flying debris. Thinking now occurs on a different kind of scale.