Abstract:
  Lunar base structures can be constructed in situ and/or shielded using unprocessed or minimally processed lunar resources with technologies utilized in harsh terrestrial regions for the past four millennia. Single- and double-curvature compression shell structures constructed using the techniques of building without centering can be applied on the lunar surface, where the low gravity and resultant small angle of repose allow for greater spans that under terrestrial condition. Suggested construction materials range from meteorites and lunar rocks to lunar adobe created from unprocessed regolith. Magma structures can be generated and cast based on natural formation, such as lava tubes and voids, using focus sunlight, microwave, plasma, and nuclear energy. Ceramic modules can be "thrown" on a centrifugally gyrating platform. These techniques integrate high-tech and low-tech construction methods of Western, Eastern, and Native American cultures, allowing for direct interaction with nature while working to economical and technical advantage by using primarily local lunar resources and human skills.

Introduction

Unprocessed or minimally processed lunar resources can be utilized for construction and/or shielding of lunar-base structures. Both life-supporting and non-life-supporting structures can be generated in situ using lunar resources by applying technologies that have been invented, constructed, perfected, and time-tested in harsh terrestrial regions for the past four millennia. Suitable human domiciles have been created using single- and double-curvature compression-shell structures--arches, vaults, domes, apses--constructed using the techniques of building without centering: corbels, dry-packs, leaning arches, pendentives, and squinches.

These techniques can be applied on the lunar surface, with its low gravity and resultant small angle of repose, and can result in greater spans than possible under terrestrial conditions. Construction materials can range from meteorites and lunar rocks to lunar adobe created from unprocessed regolith.

Magma structures can be generated and cast, based on the natural formations created by magma flow, such as lava tubes and voids, using heat-obtaining means such as focused sunlight, microwave, plasma, and nuclear energy.

Ceramic modules can be molded by utilizing a centrifugally gyrating platform--a giant potter's wheel--with high-flange rims for dynamic casting of ceramic structures.

The methods herein are based on integrating high-tech methods of Western, Eastern, and Native American cultures. This integration will not only be to economical/technical advantage, but also will create a direct interaction with nature. This will, in turn, contribute to solving the problem of the basic incompatibility of human physiology with the lunar environment by bringing about higher flexibility of responses to the challenges of everyday existence. (Mendel 1985)

Archemy

Archemy is a fusion of architecture and alchemy, integrating the timeless principles of earth architecture and ceramics through application of the accumulated human knowledge of the unity of the four universal elements to create structures and environments. Knowledge and practice of archemy can contribute to development of economical and self-sufficient construction methods for radiation/thermal/impact shielding as well s to the creation of structures for space, lunar, and Martian bases. Applications of archemy on celestial bodies can be achieved through utilizing local resources such as meteorites, rocks, regolith, ceramics, and magma in structural as well as applied without centering (corbels, dry-packs, leaning arches, pendentives, and squinches).

Rock Structures

On-site meteorites and lunar rocks in their unprocessed condition can be used for construction. Such rocks in anhydrous, hard-vacuum conditions with high rock-fracture strength (Blacic 1984) can generate no-life-supporting shelters. The method of construction with nongeometrical, meteoroid, and lunar rocks is similar to freeform terrestrial rock structures constructed with double-curvature compression, full-dome geometry. The soft-pack regolith mortar bedding and dry-pack small rock units can be used both in corbeling and tight-ring Persian and Roman-style domes. A viable method of construction with slate-flat rocks is straight, tight-fit pattern walls, such as the Native American rock walls of the American Southwest, those on the Greek Island of Delos and in the Sanandaj region of Iran. These same methods can be applied to construct curved roofs in corbeled and leaning-arch systems, which are more feasible in low lunar gravity that on earth.

As such structures cannot easily be adapted to automated systems, the method's feasibility depends on human skill and on man-material interaction. This system would be appropriate for setting up an initial outpost shelter porting rock structures can use, in addition to the preceding, fused mortar bedding as well as airtight tensile fiber.

Lunar Adobe Structures

Two main materials-and-methods utilizations of moon dust for shielding or generation structures are in the forms of automated or manually packed soil covering or Velcro adobe, and fused lunar adobe (Khalili, 1985).

Soil-packed covering in flexible dry-adhering containers (Velcro adobe), will utilize unprocessed regolith for both structures and shielding. Packed Velcro adobe in flexible containers can be used to construct structures using corbels, dry-packs, and leaning arches. In single-curvature and double-curvature compression shells, the dry adhering container texture will allow the tightness of consecutive rows, in the case of a vault, or rings in a dome, to hold up the structures in space during construction. Neither type of structure needs centering or formwork. Velcro adobe also can be used in conjunction with other conventional structures, mainly for shielding purposes.

Fused lunar adobe can be produced from unprocessed lunar soil or from the byproducts of industrial mining operations. Direct block fusion can be achieved by focused sun, microwave, plasma, or other heat generating sources. It is anticipated that vacuum conditions and the essentially zero-moisture content of lunar soils should significantly reduce thermal diffusivity (Rowley and Neudecker 1985). Fused lunar-adobe blocks can be used to construct both structures and shielding shells without centering by applying the earth architecture techniques developed over the course of millennia in limited-resource terrestrial environments (Khalili, 1986).

Utilizing an automated system of constructing a vertical, single-curvature structure, lunar adobes can complete the structure, and a postfusion process can produce a monolithic fused vault, which will be lowered to horizontal position at its final location. Both fused lunar adobe and Velcro adobe can be used for such methods, except that in the case of the latter a corbeled space must cover the vertical structure, while in the former method the total fusion will allow relocation of the structure.

Magma Structures Cast in Situ

Unprocessed lunar soil melted to the crawling consistency of magma-lava with a viscosity generated from basalt at melting point (900 to 1200 degrees C) will be suitable in malleability for casting both single- and double-curvature shells. Ceramic and fine-grained glass (Heiken 1976; Vaniman and Heiken 1985) and other lunar fluxes can be added to the main unprocessed regolith composite to lower the melting temperature to that of glass composite.

Structures can be cast in situ with generated magma either by utilizing existing lunar contours in proximity to the complex, or by forming mounds of lunar soil to desired interior spaces. In this cas, more freeform structures could be sculpted, breaking the barriers of the purely geometrical spaces created by arches, vaults, domes, apses, and cubes. These forms could approach hyperbolic, paraboloid shell structures without reinforcing tensile members. These semi-compression structures could withstand low-gravity forces if they are fused monolithically and formed in shorter spans, and when their structural membranes are working in conjunction with other geometrical forms.

Either way, the upper layers of the mounds and the apex, consisting of unprocessed lunar resources, can generate magma flow with focused sunlight (Criswell 1976), microwave (Meek et al. 1985), nuclear, or other energy sources. As the molten composite flows with the low-gravity crawl, the lave crust can form structural members in meridian and hoops generators, or spiral, circular, and multi pattern rib formations in troughs on the mound. The spaces between the rib-member structures can be fused by sintering the soil to a lesser depth that that of the members. The monolithic magma structures will eliminate the need for ribbed forms in the case of small to medium spans without the use of tensile reinforcing.

After the structural crust is formed, the underlying mound can then be excavated and packed over the monolithic shell for radiation/thermal/impact shielding (Carrier and Mitchell 1976). The method of formation of mounds can be replaced by the balloon-form spraying system (Vittore 1987) for both domes and vaults, when the application of such formworks is determined feasible in the low-gravity vacuum of the lunar surface. The spraying system will be a shortcut in mechanical separation of lunar dust, and can be achieved by bulk use of soil at its powder stage, involving preheating and Guniting the material onto the structure at the point of fusion.

The high depth of necessary soil coverage over lunar base structures is undesirable, in most cases, for both architectural flexibility and light-and-sight parameters of the interior spaces. Thus, the variable magma viscosity can be utilized to reduce the estimated 2-m thickness (Land 1985) of the packed-soil protections. The viscosity of generated magma and the soil-packed covering can counterbalance internal atmospheric pressure, while their pliability would be more accommodating to the nongeometrical forms.

Magma-Rock Roof Composites

Magma-rock roof composites can be formed by laying meteoroids or lava rocks over a mound of regolith in the form of single- or double-curvature shell forms, and void spaces can be filled with unprocessed lunar soil admixture. The loosely packed regolith-flux will be transformed to magma using a direct heat source. The glass-ceramic flux and regolith admixture, when melted, will act as the binding agent to cement the rocks into a monolithic roof structure. The formation of the regolith-rock composite can form a solid room structure with the possibility of an airtight surface which could also diffuse light. This advantage could be utilized in the areas of non-life-supporting spaces used for storage, or areas designed for horticultural purposes. Agricultural areas which can have direct light-filtering through magma-rock composite roofs, which can be built in larger spans and integrated with multilayer colored glass hubs.

Formed Magma Structures

The structures described as lunar adobe construction systems can be cas in situ vertically, then lowered to a horizontal position after the fusion process. The unprocessed lunar soil containing ceramic-glass (Grodzka 1976) can be cast as magma in its natural stage and transformed to a ceramic structure with added flux derived from the regolith. The magma casting can produce total-space modules in vault forms that are suitable for interrelated room functions. Such modules could be juxtaposed in linear, circular, and multi pattern geometries to create a lunar or Martian base complex.

A three-vault layout pattern can initiate the complex. The first vault, working as an airlock, will allow entry into the second and third vaults, which are not mutually accessible and can only be entered through the first unit.

Continued expansions of the complex will take place through both the second and third vaults, which in turn become transit routes. Thus the complex will grow by a geometric progression. The expanded pattern of the vault layout can work in circular progressions, as well as grow three-dimensionally, utilizing the single-curvature structures both horizontally as spaces and vertically as passages or chambers.

Lava Tubes--Magma Material as Agricultural Soil

Study of terrestrial lava beds and magma-lava structures and voids has shown that plant successions have taken place where suitable atmospheric conditions were present. Constructing lunar bases with a magma medium that eventually could evolve to agriculturally conducive soil will give an added opportunity to create natural atmospheres where the structures themselves could become the landscaping surfaces. Since the lunar complexes will have the necessary moisture-containing atmosphere for human habitation, plant successions could gradually evolve in the lava flats. Thus, corrosive and other deteriorating characteristics related to the aging of some manufactured building materials could, in the case of magma, evolve into agricultural soil and thus be turned to human advantage.

Natural lava formations, such as Craters of the Moon National Monument in Idaho, can provide an invaluable field study in the design and development stages. The natural terrestrial magma-lava structures can be the training site for material research, construction system studies, and horticultural development to be used in the lunar and Martian colonies. A lava tube, a long-span single-curvature structure, is generated by the flow of magma. While moving down the slope, the outer surface of the magma had formed a crust to become a vault, and repetition of the same process has created a long tunnel till the magma river is exhausted. Thus, the ultimate lessons could be learned by observing the natural evolution of lava-tube structures created by molten earth, where the material has become its own form-work, its own structure, its own color and texture finishes, its own landscape, and finally, its own total environment.

Magma Members Precast

Conventional structural members such as columns, beams, wall panels, and roofing plates can be cast in place with magma-lava composites. The casting system can utilize the trough-cast method in lunar soil beds. Solidified magma-lava structural members can be reinforced with fibers of reinforcing mesh produced from the same material through glass-fiber extraction methods. The precast panels and members can be posttensioned by tendons, or fused with spot mortar composed of materials similar to the magma, with added fluxes.

Magma-lava composites can be used to produce pipes, ducts, vertical shafts, and other members used in precast for the infrastructure of the lunar bases.

Ceramic Structures

Ceramic structures of limited spans can be cast in situ on the lunar surface. A centrifugally gyrating platform--similar to a giant potter's wheel--with a stationary center zone and movable periphery zone can be utilized to generate total-space ceramic modules. Adjustable rims with parabolic flanges can be utilized for dynamic casting of ceramic structures. A mass of lunar resources can be "thrown" in the stationary zone at the center of the platform and melted with focused sunlight to flow to the rotating periphery zone. The molten composite can form the desired shape by crawling up the flanges moving at the predetermined rate related to material and vacuum atmosphere.

The double-curvature shell structure, in the form of a giant ceramic bowl with parabolic curved upper surfaces, ca be formed to be used around a circular plant or a spinal linear corridor to create a complex. The single-curvature structures can be generated in its vertical position to avoid tensile stresses. The vaulted structures can be used in conjunction with the domes in the formation of the complex. They will each be a total-space molded module, eliminating connecting systems, such as panel prefabrication systems. In the case of the circular pattern, a seven-cluster arrangement will achieve the ultimate connection in both two- and three-dimensional designs. The seven-cluster follows the natural formation of the circle around a central core, which yield maximum space with minimum materia. Since vaults and domes can be used in conjunction to create an expandable complex, with each module as a total-space entity juxtaposed for varied alternatives, maximum use of sun-and-shade zones and minimum connecting space in the forms of pure geometries will be possible.

Individual modules can be constructed with tensile reinforcing fiber (Blacic 1984), which can be spun not the same gyrating platform utilizing glassflux composite and generating "cotton candy"-style fiber reinforcing. Such fibers could either be integrated into the shell structure of the ceramic module, or packed in sandwich formation in double-shell cavity space. Ceramic structures sandwiched with vacuum space, and/or packed with insulating materials for radiation/thermal/impact shielding, can provide appropriate permanent structures. Ceramic module spaces can also be transported for temporary shelters. Similar materials and methods could be utilized to generate lunar-base infrastructure parts, such as ducts, panels, pipes, shafts, tunnel rings, and curb modules.

Landing Pads, Roads, Walks, and Regolith Stabilization

Stabilizing lunar soil for landing pads, transportation arteries, and building sites can be achieved with on-site material and available heat sources. Moon dust with a particle size of about 70 microns, which adheres to everything and is churned up by vehicular traffic, needs to be stabilized (Carrier and Mitchell 1976). The proposed use of chemical stabilizers and emulsions, which may include both importing of materials and an ecologically damaging effect on the lunar environment, must be critically researched. As the writer proposed in the 1984 National Aeronautics and Space Administration Symposium on Lunar Bases and Space Activities of the 21st Century, the most economical, nonpolluting, and naturally harmonious process, based on the philosophy of the equilibrium of the elements, will be to directly fuse the top layers of the lunar soil.

Focused sunlight, microwave, plasma, or other heat sources can form a magma-ceramic crust to arrest unstable lunar dust. Spacecraft landing pads, vehicular traffic roads, pedestrian walkways, and all other surfaces needed for construction sites can be stabilized with a heat source, by on-spot fusion of the top layers. The sintering process can be implemented by an automatic vehicle roving over the surface with a preset, time-fusion-depth program. Stabilized basaltic, ceramic, stoneware, and other durable surfaces can be attained through this process.

Lunar Landscape

The lunar bases of the future, and the expanded colonies on the moon, Mars, and beyond, can create landscapes based on the archemy philosophy that also creates the structures. The natural composites of lunar dust, fused at high temperatures, will generate colors and textures which are in harmony with the human psyche, and in equilibrium with the universal elements. All colors of the rainbow are hidden in the gray moon dust, and will leap forth with high flames.

Flat lunar faces, as well as craters and curved contours, can be carved and sculpted in place to create forms in concave and convex shapes, ramps, walks, cityscape furniture, light posts, benches, memorials, and signs. Glaze-fused coloring of moon dust in situ can create heavenly landscapes with heavenly messages in symbols and signs. Fountains of fired-turquoise moon dust beads can quench the thirsty eyes of the tired traveler. And plant successions of leaves of grass and blossoms sprouting from lunar magma-soil can welcome the human child.

All heavenly bodies are like human bodies: marvels of creation in the highest forms of technology, yet filled with poetry and spirituality. Everything we need to build with is in us, and in the place. We must sail into the cosmos not only with zero-defect spaceships, but in ones filled with inspiration, not merely carrying a data bank, but also carrying a sense of unity integrating us with our past and future aspirations. It is good to remember that what we may ultimately reach in space may be the space within.