Lunar, Martian, and Planetary Architecture
MAGMA, CERAMIC, AND FUSED ADOBE STRUCTURES GENERATED IN SITU
Written By: E. Nader Khalili
The accumulated human knowledge of "universal elements" can be integrated with space-age technology to serve human needs on Earth; its timeless materials and timeless principles can also help achieve humanity’s quest beyond this planet. Two such areas of knowledge are in earth architecture and in ceramics, which could be the basis for a breakthrough — in scales, forms, and functions — in low gravity fields and anhydrous-vacuum conditions. With the added missing link of the element of fire (heat), traditional earthen forms can be generated on other celestial bodies, such as the Moon and Mars, in the form of magma structure, ceramic structure, and fused adobe structure. Ceramic modules can also be generated in situ in space by utilizing lunar or meteoritic resources.
Timeless Materials — Timeless Principles
The traditional techniques of building without centering, i.e., leaning-arches, corbelling, and dry-packing can have greater applications in lower gravity fields, as well as higher material strength, than in the restricted conditions of these techniques’ terrestrial origins. At the same time, the "high-tech" heat-obtaining skills of solar heat, plasma, microwave, and melting penetrators can provide ceramic-earth shelters and appropriate technology for both developed and underdeveloped nations. Through understanding and utilizing the principles of "Yekta-i-Arkan" — unity of elements — integration of tradition and technology in harmony with the laws of nature is possible at many levels of microcosm and macrocosm.
Lunar base structures can be generated and cast, based on the natural space formations created by magma-lava flow such as tubes and voids. By utilizing existing lunar contours or by forming mounds of lunar soil to desired interior spaces, structures can be cast in situ with the generated magma. 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). Ceramic-glass (Grodzka, 1976) and/or other lunar fluxes may be added to the main composite for lowering the melting temperature. Basalt melting point, 900’ to 1200’C, can be lowered to glass composites’ melting point with added lunar flux. As the molten composite flows with the low gravity crawl, the lava crust can be formed in spiral, circular, or multi-patterned rib troughs on the mound. A controlled flowing magma can cast single- or double-curvature monolithic shell structures. The underlying loose soil mound can then be excavated and packed over the monolithic shell for radiation/thermal/impact shielding (Carrier, 1976). Since high depth of necessary soil coverage over the structure is detrimental to both architectural flexibility and harmonious interaction of inner and outer space environments, the variable magma viscosity can be utilized to reduce the estimated 2-m thickness (Land, 1984) of the packed soil protections depending on material composites and attained temperature degree/time parameters. The viscosity of the generated magma and the packed regolith can counterbalance internal atmospheric pressure, and the semi-glazed interior can provide an airtight membrane. The pliability of the magma medium can present new dimensions in the creation of sculptured interiors for the ultimate functional utilization of the generated spaces. It also offers an aesthetic dimension, since the molded forms conform to human generic non-angular tendencies. The organic material of magma and the possibilities for ceramic glazing of the interior will open a new era in integration of the arts to scales unattainable for humans under the limits of terrestrial conditions. Magma materials, basaltic in particular, have produced agricultural soils and with suitable atmospheric conditions have proved to produce vegetation. Plant successions have taken place in magma-lava metamorphosis in terrestrial lava tubes and voids. Many examples of flora can be seen in old lava beds of the volcanic regions of the world. Similar conditions will be present in lunar magma structures when the temperature- moisture ambient exists for a life-supporting environment. Thus, common spaces of lunar bases could be designated as mini-agricultural zones that could both generate suitable atmosphere to sustain human life and provide supplemental nutrition resources. Natural lava structures, such as Craters of the Moon National Monument, can provide case studies in the design development stages. Research is needed to determine material composites, magma crust formation patterns, and span limitations.
Prefabricated Magma Members
Conventional structures can be built with magma in lunar base complexes by prefabricating structural members. Beams, columns, panels, and connections can be prefabricated with generated magma composed of unprocessed lunar resources fused with solar heat. Magma-lava solidified structural members can be reinforced with fibers or reinforcing mesh produced from lunar resources. The precast panels and members can be post-tensioned by tendons or fused with spot mortar composed of similar magma materials. Precast magma and ceramic members can be shaped to fit desired forms and functions. Lunar soil troughs and fused regolith layer form work can be utilized for casting systems.
The use of shielding ceramic tiles on the space shuttle points to the potential of ceramic materials for lunar and space applications. Ceramic structures of limited spans can be cast in situ on lunar sites; they can also be generated in space. On lunar sites, a centrifugally gyrating platform — a giant potter’s wheel — featuring adjustable rims with high flanges can be utilized for the dynamic casting of ceramic and stoneware structures. A mass of lunar resources can be "thrown" in the stationary center zone of the platform and melted by focused sunlight to flow to the periphery rotating zone and cast desired shapes. Known lunar resources can also be spun on the same platform to create tensile fiber; by integrating the two operations, monolithic ceramic structures with tensile fiber reinforcing layers can be generated. Double-shell ceramic structures sandwiched with space and/or packed with insulating materials can provide radiation, thermal, and impact shielding. Such units can be used singularly for lunar camps or combined around a common hub and/or spine to form a lunar base complex. The centrifugal platform system with its adjustable rim flanges can be utilized for lunar base infrastructure parts: pipes, ducts, and tunnel rings. Prefabricated sections for utility sheds can also be formed in single- or double-shell modules. In space, a centrifugally gyrating platform moving in three dimensions can create more variations of ceramic structured modules than is possible in terrestrial or gravity fields. Attached to a space station, the gyrating platform can generate ceramic modules in situ. The resources for ceramic structures can either be of lunar or martian origin or, in space, from captured meteoroids.
Fused Adobe Structure
Lunar base structures can be constructed in situ utilizing lunar adobe blocks produced from unprocessed lunar soil or the by-products of industrial mining operations. Lunar adobe blocks can be formed by the fusion of lunar resources with solar heat. It is anticipated that vacuum conditions and the essentially zero-moisture content of lunar soils should significantly reduce thermal diffusity (Rowley, 1984). Lunar adobe blocks can be used to build structures without form work, employing the earth-architecture techniques of dry-packing, corbelling, and leaning-arches (Khalili, 1986). The low gravity field and vacuum conditions, which allow for a smaller angle of repose and enhance lunar soil cohesion (Blacic, 1984), will give greater opportunity, in the case of the leaning-arch technique, for larger spans and shallower vaults and domes. The same advantages will cause the soil-packed covering to follow desirable contours for more flexible interaction of interior and exterior space and solar orientation. Fused spot-mortar or lunar dust sprayed at fusion point temperature can be used to bond the blocks in medium and large span structures. Arches, domes, vaults, and apses can be constructed to fit the contours of the moonscape; these curved surfaces can create sun and shade zones that are functionally desirable. For functional or aesthetic reasons, total or partial interior ceramic glazing of lunar adobe structures can be done with lunar resources containing glass (Heiken, 1976) and other fluxes by solar heat fusion or plasma technology. The difficulty of mechanical separation of lunar dust can be solved by the bulk use of the soil at its powder stage, involving pre-heating the dust and guniting it on the structure at the point of fusion, The techniques of earth-architecture and the human skills that have evolved to deal with natural materials and to meet the historic challenges of harsh environments and terrestrial gravity can put future men and women in direct touch with the lunar world. Discovering suitable dimensions of blocks, techniques of construction, and appropriate material composites while developing their own sense of unity with the lunar entity can be the start of human independence from Mother Earth, creating shelters in the heavens. The organic growth of lunar architecture, with its own materials and equilibrium of elements can be used to initiate an indigenous and ecologically balanced human environment without damaging the heavenly body. On Earth, one of the main tasks of architects, engineers, and builders has historically been nothing but winning the fight against gravity; now and in the future, the chance for victory on the Moon will be six times as great as it has been here on Earth.
Initial In Situ Construction
Locating a lunar lava tube may well be one of the first stages of setting up a lunar base site. Lava tubes can provide the most expedient and economical way of starting an indigenous lunar architecture. Terrestrial lava tubes are the best design model for exploring the development of appropriate life-supporting environments in lunar lava tubes. Either at the initial stage or in the following phases of lunar base construction, locating and utilizing lava tubes can be of great value. An immediate construction system for the lunar base, after the initial camp setup, can utilize unprocessed lunar resources in a non-mechanized construction system. This system uses existing rocks of different sizes and dry-pack techniques. The low gravity field and higher rock fracture strength give added advantages for larger spans of corbelling and leaning-arch earth-structure systems. Meteoroid and/or indigenous rock structures covered with lunar soil for radiation and thermal shielding can provide immediate, non- life-supporting shelters. Structures built with the same techniques can be fitted with an airtight fabric mesh for human habitation (Blacic, 1984).
Paving and Lunar Dust Stabilization
The lunar soil, with a particle size of about 70 microns, which adheres to everything and chums up with vehicular traffic, needs to be stabilized (Carrier and Mitchell, 1976). Fusion of the top layers of lunar soil with focused sunlight can form a magma-lava crust to arrest unstable lunar dust. Spacecraft landing pads, vehicular traffic roads, and pedestrian walkways can be paved with solar heat by on-spot fusion of the top layers, penetrating to desirable depth. Unprocessed lunar soil can be fused by solar energy via a manual or automatic and remote control "paving" vehicle. Inappropriate regolith areas can be topped with a layer of appropriate lunar soil before its fusion. For low temperature fusion, lunar fluxes can be sprayed on top of the soil prior to introducing solar heat. Paving surfaces of heavier traffic areas can be constructed from composites fused to ceramic and stoneware consistency with desired colors and textures. As a general rule, it is the use of the universal principles of the terrestrial element of fire (heat) — the solar rays — that must be thought of at the forefront of mediums and materials for planetary base design and construction. Adhering to the philosophy of the use of local resources, human skills, and solar energy, we can achieve our quests on the Moon, Mars, and beyond. We must learn from the accumulated human knowledge of earth-architecture, which has sheltered humans in the harshest conditions. Each person going to the Moon, regardless of his or her work, must be aware of these fundamental principles and techniques to participate in creating an indigenous architecture to form their communities, not only because of economic benefit but also because of spiritual reward. As an old Persian saying goes, "Every man and woman is born a doctor and a builder — to heal and shelter himself."
Acknowledgments. The Geltaftan Group, consisting of Manouchehr Sedehi, Mahmoud Hejazi, Ezzatollah Salmanzadeh, Ali Gourang, Ostad Asghar, and A. A. Khorramshahi, supported my work in earth-and-fire developments. Eyal Perchik, Alessandra Runyon, Tsosie Tsinhnahjinnie, Steven Haines, Ellwood Pickering II, Barclay Totten, students at the Southern California Institute of Architecture, have helped advance my research work.
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