Functional communities must physically evolve to exist –a simple fact often ignored by urban planners and architects and which applies just as much in space as on Earth. A town or a city is not so much a specific built structure as it is an emergent phenomenon, created by a convergence of individual interests upon a single logistically advantageous location, its form a physical manifestation of environmental constraints and a collective social situation that can –and almost always does– change, sometimes slowly, sometimes with alarming speed.
Simple ‘outposts’ such as today’s current space stations have less need of physical evolution since they are, by definition, temporary or transitional facilities. Though their typical use of modular component systems would imply a potential for perpetual adaptability and repairability, their designs really do not accommodate this. They are intended for a fixed duty life, after which they are demolished. Even the elaborate International Space Station of today is destined to go the way of its Mir predecessor, ironically probably not very long after its much-delayed completion. The use of modular structural systems with these structures has more to do with the limitations of the launch systems used to construct them than their functional aspects. The ISS could have been designed as a very large single-piece module like the SkyLab of the 1970s launched whole by some gigantic specialized launch vehicle and it would have had little or no effect on how it would have ultimately functioned. (other than saving a lot of time in actually deploying it)
For the true orbital settlement, there is a presumption of perpetual existence coupled to perpetual evolution of function as situation and needs change. To exist perpetually in spite of entropy, in the form of simple wear and tear, a structure must be totally and incrementally repairable or replaceable. To freely evolve, it must be infinitely flexible, adaptable, and expandable. It must be structurally generic –its core structural system able to assume any purpose without limits. This underlying generic structural system may not always be apparent on Earth because buildings tend to be designed as discreet structures based on a broad spectrum of building methods and technologies. But it’s most certainly there. It’s the ground all buildings sit on and the network of roads and streets and underground infrastructure systems that link them together. Our civilization is largely a wholly contiguous structure –even if the basis of that structure is a ‘found’ structure created by nature and employed by adaptive reuse. Very few buildings exist alone and disconnected from the rest of the civilization. Very few people live in isolation from the global infrastructure –whether linked by just a footpath or a superhighway. In orbital space there is no natural ground to serve as a primary structure and no gravity to hold structures to it. So a comprehensive macrostructure becomes necessary to physically tie the orbital habitat together while affording that same ground-like flexibility and perpetual adaptability. And with no specific ‘up’ or ‘down’, it must do all this with a volumetric topology.
To date, all orbital structures have been designed in the peculiar fashion of discrete free-floating self-contained buildings –houses and skyscrapers in space. They are often referred to as ‘habitats’, but have few of the characteristics of a comprehensive habitable environment. For temporary outposts this is fine but for true settlements the notion of any structure of fixed design being perpetually suitable is nonsense, nor is it practical to treat the increasingly crowded (and increasingly jealously guarded by national and corporate interests) Earth orbital space as open real estate for an infinite number of facilities. What is needed then is not discrete structures but a structural system independent of specific purpose that facilitates the habitation of space in general.
In the section on the Aquarius phase we explained that in TMP2 we no longer perceive Aquarius as an individual project or specific marine colony design. Instead, we discussed a way of inhabiting the sea based on a spectrum of technologies that are infinitely flexible and evolvable from a small initial scale but tend to produce a certain spectrum of forms as a consequence of the conditions of the marine environment, the logistical situation of living in the middle of the open equatorial ocean, and the likely path of evolution for a marine settlement. With the EvoHab concept we present this same concept in the context of Asgard. The Asgard phase is no longer about creating a specific structure and project. With the EvoHab concept it is now about a way of inhabiting the orbital space environment that will suit an infinite variety of applications and structural designs. We can no more realistically predict every aspect of the evolution of the space habitat than the founders of New Holland could predict the ultimate form of New York City. But we can speculate on some likely macroforms as a consequence of the conditions of the space environment, the logistics of orbital locations, and the likely path of evolution starting with any of the earlier types of orbital structure; MUOL, MUOF, MOF, and Valhalla.
The foundation of the EvoHab would be the same space frame structural system and infrastructure architecture of the previous MUOL and MUOF facilities. The key advances on these are the ability to support structures of larger scale and to employ a built-up pressurized hull technology that improves upon the pneumatic hull systems employed by MOF and Valhalla stations. EvoHab is also based on two key architectural concepts which we discussed in the article on Life In Asgard; the Core Truss and the Urban Tree. These two concepts embody a basic theory of organizing space in space which we will see expressed throughout most of the structures of the Asgard phase, the Core Truss representing the essential macrostructure employed by most large space structures and the Urban Tree the basic strategy for turning that into an evolvable inhabitable space.
EvoHab is intended to address what may be the single-greatest (and most commonly over-looked) logistical issue with space habitation; the simple situation that, within a space habitat, you cannot manufacture anything bigger than you can fit through a pressure hatch. Future space habitats will certainly employ structures with quite large hatchways. Sizes of several meters across may be common. But compared to large structures like spacecraft and whole habitats, this would still be very small. This fact presents one with the puzzle of how to fabricate large structures on orbit from space-sourced materials processed in space. There are only three basic solutions; reduce a structure to small modular components that can fit through hatches, employ demountable construction enclosures that create very large temporary and possibly pressurized spaces, and fabricate in-situ in the space environment. All these approaches are likely to be employed by the inhabitants of Asgard settlements but the most immediately practical is likely to be the first; modular component systems. Demountable enclosures will require some kind of modular component system to build them with and, unless pressurized, can only provide dust and thermal shelter while true in-situ fabrication in the ambient environment of space is extremely difficult to do with any kind of precision and consistency given any current and near-term fabrication technology, limiting in-situ activity to some form of assembly of prefabricated parts. Thus the EvoHab system is based primarily on modular components, though employs some aspects of a demountable enclosure system in the production of its unique form of hull structure.
Key to the EvoHab concept is its hull technology; a modular component composite hull system resulting from a progressive evolution in pneumatic hull technology starting with TransHab type prefabricated pneumatic structures. TransHab hulls are all-in-one pneumatic hull structures composed of multiple layers of flexible material and polymer foams that form a composite pressurized hull structure. Their foam materials are compressed to a very thin and relatively flexible state then expand and rigidize upon inflation of the structure, creating a thick multi-layer impermeable composite material that combines the functions of micrometeoroid, thermal, and radiation shielding with pressure containment.
Unfortunately, this form of hull structure is not as compactable as it could be because the many layers of foam and impermeable membranes or fabrics are not as flexible as they could be in this combination. For the maximum compactness of a pneumatic hull system one needs to fully decouple the function of shielding from pressure containment. Thus later systems are likely to combine a simpler thin pneumatic pressure hull that can be very tightly compacted with modular shielding panels that may attach directly to this pressure hull when inflated (using industrial Velcro or future ‘mechanical adhesives’) or attach to a space frame providing structural support for both. This can potentially allow for much larger volume prefabricated pressure hulls than is possible with the other hull type and allow much of the structure to be fabricated in space from relatively small modular parts. It also allows for a very high degree of repairability and adaptability as these more modular components can be replaced independently and reconfigured to suit different combinations of the pressure skins they shelter and support. As we’ve discussed in previous articles, this technology derives from enclosure systems developed for MUOF facilities and is the likely form of hull technology employed in MOF and later stages of Valhalla station development.
However, this kind of hull system is still limited by the need to use contiguous pneumatic membranes that will, for some time, be very difficult to fabricate in space at large scales even if they can be compacted sufficiently to fit though pressure hatches, making them dependent upon terrestrial production. To overcome this, and to be able to construct the truly vast hull structures of city-sized settlements, a system based completely on smaller-scale parts becomes necessary.
Thus we arrive at the EvoHab modular composite hull system which would employ a space frame enclosure structure supporting a hull system formed of two basic kinds of modular panels; external shielding panels and internal substrate panels. These two kinds of panels would be similar in that they would be composed of multiple layers of rigid light structural foam and alloys (possibly foamed alloys), use formed-in place alloy attachment that both connect them to the space frame and provide pass-through connector sockets for additional surface attachments (very much like the formed-in-place socket grid used on Aquarian construction for retrofit finishing components), and they would feature precision standardized geometric shapes conforming to the geometry of the space frame system they attach to. They would differ in that the shielding panels may consist of very thick materials to provide radiation and micrometeoroid shielding as well as have integral electronic sensors to detect significant impacts or damage so they can be quickly identified for replacement. The interior panels would be thinner and engineered for planar tensile strength and would serve as substrate panels for the application of a sealant material that fills the seams between panels and creates a contiguous impermeable pressure hull structure. These interior panels would also include electronic damage sensors and possibly some auto-sealing feature in the form of an integral layer of bi-phase viscous material that expands into a foam to seal small penetrations of the panel.
Thus an EvoHab hull structure would be created by first assembling an enclosure space-frame from modular parts. The two kinds of panels are then attached to this, the panels now creating a relatively sheltered environment inside the structure. The interior substrate panels are then sealed with a sprayed material (which could be –and most likely early on– polymer based or based on sprayed molten alloys) to create an impermeable hull that can then be pressurized.
The pass-through sockets on the panels now allow for the surface-mount mechanical attachment of additional components on both sides of the hull. This is an important feature because it affords us the option to attach such components as solar and radiator panels to the structure or, much more impressively, to make this hull system light and image ‘transmitting’ even though these materials may be very thick and opaque. In Marshal Savage’s original design concept for the Asgard orbital colony he suggested creating a habitat based on an enormous transparent pneumatic membrane hull system filled with water, the idea being to create a habit environment that aesthetically embraced the nature of the space environment rather than trying to recreate the Earth in miniature as had been the common strategy of large space habitat designs of the past. Though an aesthetically pleasing idea, this kind of hull system proved technically difficult given any known technology, Savage himself offering no suggestions for how it would actually be fabricated. However, one doesn’t need a transparent material to make an effectively transparent structure given the benefit of current photonics technology. Combining optical fibers with holographic membranes for heliostat collectors and emitters, it becomes possible to pass light through a small optical cable passing through an otherwise opaque material of some great thickness. Currently, this can be readily done to communicate ambient light, creating the possibility of such novel structures as concrete shell greenhouses. True image transmission is also possible, but more difficult at present. It may be facilitated with emerging new optical systems based on metamaterials exhibiting negative indexes of refraction with visible light. (a feat often attributed with the prospect of creating optical ‘cloaking’ devices) Or can also be accomplished by combining ambient light transmission with simple mass-produced video camera and liquid crystal display technology to communicate an image projected with the ambient light, creating what could be called a ‘virtual window’.
This may seem a rather elaborate and expensive way to make something as seemingly simple as a window. However, the ultimate Asgard settlements are going to be located in GEO, where they do not have the protection of the Earth’s magnetosphere and thus need much thicker materials to provide radiation shielding compared to a LEO facility. Thus making such a thick strong window from typical brittle transparent materials –or even future materials like diamondoid– and mounting it within a pressure-tight fixture becomes very expensive in terms of assembly and mass –especially if you intend large or numerous windows. And to make matters worse most supposedly transparent materials aren’t all that transparent at great thickness and convert the light they absorb into internal waste heat. In comparison, a few small optical components and mass-produced video cameras (which today can put better than human eye resolution into a quarter coin size package) would be much lighter and need much less material and thus could be far cheaper and safer. For a large virtual window, primary illumination would be provided by transmitting ambient light from the outside while integral photovoltaics would power the small imaging camera and projection filter, making a system completely independent of any central power source and thus highly reliable.
Contrary to the visions of spacecraft in SciFi, most spacecraft of the near future are likely to rely heavily on video imaging for external views rather than any large windows. (one of the few instances where Star Trek actually got it right compared to the rest of SciFi…) Indeed, even today the cost of virtual window systems could be competitive with the cost of conventional windows were video display technology to catch-up with video imaging technology in cost-efficiency. In the near future we may actually see architects experimenting with designs for windowless buildings that appear totally transparent from the inside by virtue of virtual window systems, thus allowing one to bring the outdoors inside aesthetically without concern for privacy or thermal gain and loss.
Whether image transmitting or just diffuse light transmitting, such windows would have many advantages. They would be able to filter light for the most effective spectrum and light levels and could be turned on and off like electric lamps to create a night time period even when, in GEO, a habitat is almost continuously exposed to sunlight. It would also be possible to use the inner hull as an enormous live graphic display, be it to simulate an Earth-like sky, to project artwork, provide entertainment, or function as a public information display.
Another advantage of this kind of light transmitting hull is that it would allow for integral solar power collection. Much of the optical radiation a space habitat is exposed to is unnecessary for interior illumination, particularly in the IR and UV ends of the spectrum. Photovoltaics designed as in-line optical filters or associated with them can thus extract these portions of the spectrum collected and concentrated by the light transmitting window system and convert it to electric power, while passing the usable light on to the interior. Thus the entire surface area of a habitat hull could be made virtually transparent and function as a solar power collector.
This technology also has important industrial applications. Farming, for example, requires an extremely high efficiency of space to be performed on orbit and that means being able to distribute light in new ways. A solar greenhouse may be designed with a series of plant-supporting hydroponics frames in the form of concentric interior cylinders which must each be illuminated from either side. This technology would allow such an orbital greenhouse to collect natural light all over its hull surface as well as on dedicated external sun-tracking panels and then distribute it to concentric layers of double-sided panel emitters just like LED or electroluminescent panels, one layer between each concentric layer of plant supports. Similarly, a habitat’s light-transmitting hull system could be tapped as a source of natural spectrum lamp light distributed throughout interior structures on a fiber cable grid like electricity. This will prove very valuable in the later development of lunar and planetary settlements based on excavated habitat structures.
Using this basic hull technology, the EvoHab system would allow for the creation of pressurized spaces and structures of most any size and shape that can in some way be reduced to a modular panel geometry and an enclosure space frame. But its chief application would be the creation of relatively large hull structures that are impractical to produce with wholly prefabricated pressure skins. By decoupling the functions of structure, shielding, and pressure containment and reducing them to individual mechanically attached components, the EvoHab hull allows for perpetual reparability, adaptability, and incremental expansion of large pressurized space structures on orbit, allowing a habitat to freely evolve over time just as the built habitat on Earth does. Hulls can be expanded by concentric growth –by removing shield panels and creating a new pressure hull structure outside the older one then dismantling the old pressure hull from the inside– or the projection of extensions off an existing structure where space frames can be geometrically integrated. Owing to the need to minimize the acuteness of angles with the engineering of a pressurized structure, most hull shapes produced with this system would employ roughly tubular, cylindrical, spherical, and saddle polyhedra forms.
Primary structures of EvoHab habitats would be based on the simple structural idea of branching core truss networks which provide primary attachment for enclosure hull systems surrounding them and other functional elements within them. The essential model is the prefabricated TransHab pneumatic hull module; an inflatable hull shell supported by an internal truss serving as the primary attachment point of all functional parts within it. This concept extends to the design concept of the manned BeamShip and the Valhalla station, where the core truss of a TransHab cabin compartment is extended to provide an external attachment structure for the functional elements of a spacecraft, such as solar and radiator panels, rocket thrusters, and so on. EvoHab takes this basic design concept to the megastructure scale, with very large hull enclosures intersected by large core trusses which are then ‘brachiated’ into an ‘urban tree’ filling out the vast open space within the light-transmitting hull enclosure. This urban tree becomes the primary habitable space of the habitat, its ‘branches’ fleshed out with retrofit buildings and other structures made of light materials. For the light-transmitting hull the urban tree would seem as though suspended in an infinite diffusely illuminated sky. For the image-transmitting hull, the urban tree would seem suspended in space, its enclosure hull virtually invisible from the inside unless one was very close to it.
The full-scale EvoHab based Asgard GEO habitat could employ an unlimited variety of shapes but, because we suggest that these large permanent habitats would evolve from specific smaller earlier space platform like the MOF and Valhalla stations, we anticipate that the most likely primary configuration to emerge would consist of a single or small cluster of very large spherical enclosures intersected by one primary polar core truss aligned vertically relative to the Earth. This would feature smaller cylindrical hull structures at the polar ‘caps’ serving as agricultural and CELSS (closed environment life support system) structures and then a set of MUOF/MOF type platform ‘wings’ extending perpendicularly from the ends of the core truss and providing solar power, industrial facilities, and a series of docking facilities. This configuration is the most likely to evolve out of the previous types of platforms and would be one of the easiest to incrementally ‘grow’ by simple concentric expansion of an initial hull structure without disruption of its interior pressurized environment. In many ways this configuration is reminiscent of Marshal Savage’s original Asgard habitat concept, except its hull is only transparent from the inside. From the outside it would appear as an enormous geodesic sphere with a surface akin to the compound eye of an insect. The potential size of such a habitat would be virtually unlimited. With the same basic configuration, it could grow from the size of a small town to a vast city with a huge and elaborate urban tree complex within it.
Since the urban tree is the place where most activity in the settlement would take place, let’s consider its design and structures in a little more detail. We discussed much of this in the previous article on Life In Asgard but here we’ll consider more specific structural features.
Core Truss: Not just the primary structural feature of the habitat, this is the primary via through it and between its interior and exterior areas. A complex of modular bulkhead units at the polar/axial caps of the pressure hull would provide large hatchways between exterior structures and provide pass-through interfaces for all the utilities systems of the habitat. Retrofit utilities conduits would run along the surface of the truss, often hidden behind panels that define transit vias for human beings as well as automated transit systems based on linear motor tracks. It may also feature its own secondary pressure hull compartments, intended to provide shelter in emergencies. For the large settlement, this core truss may itself become quite enormous –many tens of meters across. Thus it may also employ a more corrugated structure in the form of a radial cluster of ‘tunnels’ through it. Towards its center it would tend to ‘branchiate’ into a series of smaller secondary branches serving as attachment structures for individual buildings in the habitat, most of which would be attached to the outside of these truss structures but accessed through the truss vias. This is how we arrive at the notion of an ‘urban tree’. During emergencies such as solar flares or more major hull breeches the core truss would be used as a mustering point for settlement inhabitants and employ additional radiation shields and deployable emergency shelters in which residents can ride out the event.
Utilities Systems: Polar or axial ends of the core truss would tend to concentrate utility equipment, growing in scale from small systems to large plants all retrofit to the core truss. Life support systems would be integrated to the CELSS portions of the agricultural modules outside, with large radiating clusters of external air and water tanks around the polar/axial cap functioning like capacitors in the system. Around the life support plant one would likely see arrays of fans of some kind with integral electrostatic filters and gas absorbers, intended to scrub particulates, moisture, and waste gases from the atmosphere. The control of mold will be a particularly important –and today sometimes overlooked in space habitat design– aspect of life support as this has proven a particular problem of the very ideal climates inside space habitats. This is not only a health issue; mold is also able to consume many polymers and cellulose based materials leading to damage of the settlement’s systems.
The core truss structure of the habitat would be the primary conduit for a utilities bus that would include power, digital communications, thermal management, ducted air, water, blackwater waste, graywater waste, collected sunlight, and eventually molecular materials in liquid suspension called NanoSoup for use by nanofabrication and nanorecycling systems.
Many systems in the habitat may employ the use of optical power as employed on the early MUOL in order to isolate the power bus from surges and noise as well as a means to minimize potential for fire. The use of fiber optic distributed light, sourced from both external heliostats and internal centralized ‘light pumps’ would also aid in this and afford the use of simple lighting systems using modular parts that can be assembled and installed without tools, used safely in wet areas, and attached or embedded into many materials considered unsafe for electrical conductors.
Fluid transport is more complex in microgravity, making the design of water and waste systems rather different than terrestrial counterparts. Water transport in space relies on systems that pressurize water in various ways in order to push it through pipes in the absence of gravity. Similarly, any kind of ‘drain’ system must employ systems that can create a vacuum. The handling of human waste as well as other forms of organic waste will be particularly challenging. To date, all spacecraft and space stations have relied on various forms of ‘packaging toilets’ that may also include a waste incineration stage to reduce this to a dry material. This is inadequate for the large-scale facility, especially when employing CELSS, while pressurized transport of liquid unprocessed blackwater wastes may be problematic. Thus a system combining incineration at toilets and other collection points reducing organic waste to inert ash with a pressurized graywater liquid transport may be a more practical alternative.
With the introduction of more comprehensive nanofabrication systems new means of molecular materials transport will become necessary to facilitate more efficient distribution and recycling. Most early nanofabrication systems will likely employ materials in specialized liquid hydrocarbon suspensions distributed in cartons and cartridges as used with today’s ink jet printers. But with increasing sophistication will come a demand for a larger materials spectrum including some prefabricated nanocomponents, making such carton handling increasingly problematic. This author has suggested an eventual solution in the form of a universal nanomaterials suspension called NanoSoup which would rely on nanochip devices to extract and sort materials on demand, thus creating a kind of materials Internet that may eventually be implemented at the scale of a global pipeline utility network. This, of course, is likely to be employed on Asgard settlements as well, the special piping using ‘cilia-transport’ as well as in-line peristaltic pumping. This pipeline could replace the need for waste transport in the habitat by virtue of the use of local recycling by nanochip disassembly and then injection into the NanoSoup network. Water distribution may also employ this network. Even atmospheric systems may integrate into this network, as a means to dispose of filtered wastes and as a means of obtaining small amounts of supplemental gases.
Public Transportation: Orbital habitats are likely to go for a very long time without a need for any large-scale transportation systems, owing to the greater compactness and shorter transit paths of the volumetric habitat compared to typical terrestrial cities that rely on a 2D organization. Demand, however, is likely to emerge through the need for materials handling where automated transit can keep materials under greater control in the absence of gravity. Tracked pallet transfer systems will, by the time of the large Asgard habitats, already be in common use on MUOF and MOF facilities and would be a natural addition to EvoHab structures. By adding to such systems a pallet module equipped with a kind of chaise lounge seating passengers strap themselves into, a simple automated passenger transit system for microgravity would be possible.
In addition to this, a type of tether transit system or ‘StrapHanger’ may be employed based on the use of a trigger-activated hand-hold or hand-strap with a linear motor element that can propel itself along a powered tether, towing the holder of the device along. Additional carbineer loops would be used to attach small payloads to the same device. Radio sensors, perhaps based on a form of time-domain reflectometry, would allow the StrapHanger units to sense distances from each other and tether ends through the tether itself, allowing them to break and stop automatically. This form of transportation would likely be employed poin-to-point in large open spaces and in temporary installations for construction sites. It might also be implemented in rigid rail form within the core truss structures and buildings. But, since passengers or payloads would tend to be thrown by their own momentum during acceleration and breaking, the system would be limited to quite slow speeds. Using multiple tether interface points and multiple tethers, this same system would be able to support more rigid pallets and chaise lounge passenger carriers and higher speeds.
Fully free-moving vehicles are also possible and likely thanks to the large open spaces of the EvoHab but present special safety issues and so may be limited in size and speed as a result. These vehicles are likely to evolve from the same technology developed to provide free-roaming mobility to robots or FlyBots, both inside and outside the habitat. Using nitrogen or compressed air thrusters and control systems much like that of underwater robots, these robots are likely to assume a great variety of roles in the habitat from personal communications to various forms of maintenance, and use as ‘remotes’ through which AI residents of a settlement would be able to interact with the physical environment of the habitat. One of the more important of these would be the robotic carrier pallet, used as a simple materials carrier and as a self-mobile tool box for technicians. From this design is likely to evolve larger systems with chaise lounge seats and simple roll cages a passenger straps into and pilots by control pucks or joysticks and armrests. These RocShaws (rocket-rickshaw) vehicles would be in some ways similar to the Man Maneuvering Units once employed by Space Shuttle astronauts, only intended for the pressurized environment inside large habitats and supporting up to a few passengers and/or cargo carriers. Though robotically-assisted for automatic station-keeping and collision avoidance, these vehicles would require some skill in operation and may become the basis of recreational activity. Pressurized variations of this sort of vehicle, equipped with robotic arms, have also often been suggested in futurist literature as a more convenient means to EVA than space suits and as an easy means of short-distance transport between stations and spacecraft. This is a likely possible application for RocShaw systems, though it may be more likely that telepresence controlled robots will prove at least as capable, much more compact, and much safer.
An even more personal-scale form of transport would be based on a single simple thruster strapped to an arm, though these devices would have extremely limited propellant reserves and so are more likely to be employed as a means of extricating oneself when stuck out of reach of handholds in free-space.
Buildings and Dwellings: in a microgravity, structures do not have to bear loads under gravity and in the controlled atmosphere of the habitat they need not deal with weather. Thus the buildings of the urban tree need only provide rigidity, privacy, and sound insulation. The buildings and dwellings of Asgard settlements are likely to employ a very novel and sophisticated form of ‘tent’ architecture relying on the use of fabrics, soft and rigid structural foams, modular space frames, and tension structures. A typical modest-sized personal dwelling may appear like a kind of soft-sculpture, a radial cluster of purpose-specific chambers made of fabric-covered structural foams over a light frame structure with the whole thing held together primarily by a few mechanical connections , tension cables, Velcro, and future ‘mechanical adhesives’ or nano-velcros. Many designs, utilitarian to whimsical, are possible along with the integration of large variety of light materials, including wood and bamboo. Given that textiles may prove one of the easiest and first industrial products suited to microgravity production, they are likely to feature largely in dwelling design.
Some dwellings may be totally prefabricated and compacted into a small package for storage and transport, others based on modular component systems, perhaps deriving from the UtiliHab system developed and employed on Aquarius settlements. They will tend to be smaller in volume than terrestrial dwellings because, in a microgravity environment, the whole surface area of rooms becomes functional space, rather then being divided into floor, wall and ceiling areas of differing utility. Asgard inhabitants will also be a full generation into the Post-Industrial culture and so would tend to have much less need of large collections of personal items and the space to store them all. Most of the average person’s ‘property’ in this age will be digital information and many –if not most– physical goods will be considered temporary. This is not to suggest that the inhabitants of Asgard will not have the normal desires for comforts, pleasure, and luxury like some clichéd Spartan super-race of SciFi or paleo-futurist visions. Rather, with digital media and communication increasing in convergence of physical hardware (reducing the diversity and volume of devices needed to enjoy the full spectrum of media and communications) and as a measure of standard of living while a steadily increasing volume of goods become quickly made and recycled on demand in one’s own home, people will feel less of a need to be surrounded in some large on-hand supply of stuff in order to feel comfortable and will define luxury more in terms of design sophistication and novelty rather than the scarcity of materials something is made from.
The basic organization of space using the large light-transmitting hulls would be that of variously connected interiors suspended in a large virtual exterior volume. Inhabitants would traverse a largely interiorized network of spaces while the open exterior space would be visible through unenclosed portion of frame structure and through window portals –which generally would be open or based on screens or membranes since they don’t have to provide a weather barrier. As noted in previous articles, in microgravity there isn’t much functional use to large open spaces that exceed the ‘body span’ –the average reach of human limbs– as one cannot walk around in microgravity but rather must pull and push oneself about by hand and foot holds. Large span spaces present the risk of becoming ‘stranded’ in free space. But people do need a sense of open exterior space for psychological comfort and will certainly try to make use of these spans in some way for recreational activities, even if it means employing some contraption or another to move around, such as the personal thrusters and light robotic thrust-propelled vehicles eluded to in other articles. Thus many dwellings are likely to feature external ‘terraces’ of some kind in the form of light cage-like enclosures that allow one to casually immerse oneself in the large open space area without the risk of absently drifting off. These structures are likely to be designed like ‘bowers’ or ‘gazebos’, decorated in plant life that uses the cage structure as the basis of a hydroponics system.
Larger buildings are likely to employ a kind of sub-frame structure integrating to the primary truss structure of the habitat, employing structural foam or pneumatically rigidized panel systems with likely saddle-polyhedra geometries and rooms designed largely around the equipment they host and the frames they attach to. Functional spaces will tend to be designed around the limits of ‘body span’. This will tend to favor ‘strap in’ workstations, radially organized tubular workspaces, and large parallel planes with a modest gap between them and grids of hand-holds and ‘perching’ points. In this Post-Industrial age, most so-called ‘white collar’ work would be done at home and most employment in general on-orbit would be technical, design, or information based in nature. Thus, where larger buildings are employed, they would tend to be associated with particularly large types of equipment unsuited to residential installation or, for that matter, full automation and location in the non-pressurized industrial portions of the extended settlement structure.
‘Office buildings’, common to 20th century cities, may be largely obsolete by the late 21st century as centralized ‘commercial’ facilities owing to the demassification and increasing automation of industrial production and the corresponding demassification of commerce through ubiquitous Internet use as well as a balkanization of urban centers into multi-use microcity complexes, bringing a focus back from mass commerce to residence. Any necessary mass industrial activity performed by the orbital settlement will likely be relegated to external industrial facilities while on-demand production would be relegated to household systems and small personal workshops. Thus exceptionally large buildings may be relatively rare in the urban tree habitat and relegated to very specialized purposes. Laboratories and media production facilities are likely examples. The novelty of large microgravity habitats and their unusual lifestyle characteristics may produce a strong demand for mass media production from them, perhaps becoming one of the major industries for these communities.
Recreational Structures: A great variety of recreational facilities are likely to be devised by the inhabitants of Asgard –more than can possibly be detailed here. However, we can anticipate that these will tend to be focused on three areas; public assembly spaces, open space sporting activities, and the recreational use of water.
Public assembly is something of a problem in microgravity owing to the way people must move through structures using hand-holds and thus the need to keep spaces within the ‘body span’ to accommodate that. Public performances and presentations usually demand an unobstructed view of a central space for a relatively large number of people. But this, in turn, tends to create large spaces that exceed the necessary body span limits. For small groups of people, simple circular flat ‘theaters’ or ‘conference rooms’ wide in one plane, narrow in the opposite plane, are likely to be employed. This is a likely approach to other group facilities such as dance halls. This, however, limits the sharing of a view to a single circle of people, completely blocking the view of those outside that circle. Classical architecture solved this problem on Earth with the invention of the amphitheater putting viewers on sets of concentric seating terraces around a central space. But traversing such a structure in microgravity would be difficult owing to the large overhead volume necessary to insure line of site. A possible solution to this would be to create an amphitheater the viewer traversed from behind/underneath, climbing in from behind to a ‘perch’ or lounge with an unobstructed central view. Such a theater structure could be made completely spherical, though in general only a middle section would offer a useful view (leaving ‘polar’ space for lighting and stage structures) and any live performers in the center are still left with their own challenge for moving about within the large open space. Many variations on this sort of structure are likely to be experimented with.
Sporting activities present similar problems in coping with the use of large open spaces, further complicated where the ‘surface’ of an ‘arena’ like space may need to double as structure for spectators to sit. Human movement across large open spaces is likely to rely heavily on enclosure walls as surface from which people can push to vault across the open volume. This would necessitate some type of barrier between spectator ‘perches’ and this vaulting surface which, obviously, must be able to be clearly seen through. Tough plexiglass panels, highly tensioned membranes, or net enclosures may be a likely solution. (for non-spectator sports opaque cable-stayed tension fabric or net enclosures are likely)
Very large area sporting activities will likely employ a variety of cable-stayed structures for their facilities. A good example may be recreational or sport activities based on RocShaw or teleoperated FlyBot piloting or antonymous FlyBot competitions where competitors must navigate these vehicles through complex obstacle courses or use them to physically propel objects as in the manner of the game polo. Here spectators would need protection in roll-cage and net sheltered structures while observing from a distance.
Recreational structures involving large volumes of water would be particularly challenging to develop and may not be feasible at all for some time. But since this is an extremely important element for recreation –particularly for generations of settlers likely to have grown up on Aquarius colonies- much experimentation in this can be expected with space settlements. Containment of water is the chief challenge in a microgravity environment. For small bodies of water pressure compensation and surface tension may be sufficient to allow for the creation of small baths inside special water enclosures. In more open spaces, though, the use of some form total containment or some kind of centrifugal containment may be necessary. Aquariums of various kinds may be experimented with, the microgravity environment presenting the novel possibility of membrane aquariums based on slightly pressurized transparent balloons in various shapes that can be cable-stayed in position. Larger structures of this kind may be possible for use by swimmers equipped with breathing apparatus and accessing the water-filled spaces via airlocks, but this may not be consided convenient for many. Centrifugal confinement of water is likely to have been the subject of experimentation in the development of Valhalla scale space hotels and could potentially be employed on a larger scale through the construction of ring enclosures that employ hydrojets in their wall to maintain a slow constant circulation of water along the walls with an air-filled central space. This would favor very large structures of this sort since casual swimmers would tend to be carried along in this current and a small radius pool with a high water velocity would become disorienting.
Gardening: Contemporary spacecraft and stations have yet to explore the aesthetic use of gardening owing to the extremely utilitarian nature of their designs. But for the large settlement this is likely to be an architectural priority. As EvoHab settlements grow, an endless assortment of containerized hydroponic gardening systems and plant species are likely to be experimented with as the basis of decorative gardening. For small planters various aeroponic systems are likely where the roots of an individual plant are held by a polymer gasket around the plant stalk inside a small chamber where misters supply nutrient. Larger systems are likely to employ various forms of large area feeder and anchorage structures suited to collections of plants. These may culminate in a system called SkyGarden based on the use of space frames using hollow tube struts composed of semi-permeable ceramics or similar materials in a polymer sheath. Working as a variant of Nutrient Film Technique hydroponics, pressurized nutrient solutions would be supplied through this hollow tube frame structure to plant roots held in place under the polymer sheath, allowing the structure to provide both life support and anchorage to the plants. Space frame nodes would also allow attachment for non-feeder frame structures and other equipment, such a fiber optic light emitters, electric lighting panels, misters, sensors, fans, and light latticework used just for plant support. This system could be configured and integrated to the habitat structure in a great variety of ways and to most any scale, serving as the basis of household terrace enclosures or being used for large intensive farming. With such a system, the urban tree of the Asgard habitat could become a very literal analogy indeed as the core structure becomes covered in various forms of plant growth.
Industrial Facilities: A noted previously, the large EvoHab habitat is likely to employ external MOF-style facilities for both its industrial activities as well as its primary solar collector/radiator arrays. Aside from their attachment to the core truss structure of the habitat and need for more manned spacecraft support, these would be largely identical to the basic MOF architecture, employing a large planar truss structure whose surface hosts solar and radiator structures and whose multi-layer interior volume is enclosed in modular shield panels to create a vast sheltered but non-pressurized space.
In addition to this, however, would be several large radial cylindrical-shaped pressurized structures using the same hull technology as the main EvoHab enclosure and serving the purposes of intensive farming and CELSS. Relying on both electric light and the use of dedicated heliostat arrays providing light to fiber optic lighting networks, these facilities would employ concentric arrays of structures with interleaved light emitters or panels to provide a dense cultivation environment suited to robotic maintenance. Plant and algae cultivation are likely to be the primary focus of these facilities, though various marine animals may also be suited to cultivation using membrane aquarium enclosures or a moisture-saturated atmosphere rather than complete liquid environment. Tissue culturing –a possible medical export industry on orbit- is also another likely alternative to conventional agriculture, given the difficulty of caring for terrestrial animals in a microgravity environment, such activity likely to be conducted in something of an automated pressurized laboratory setting using a prismatic array of long culturing system lines. This would reduce the production of meat products to something very similar to hydroponics farming. Bizarre as it may seem, even dairy products may be producible by such cybernetic tissue-culturing techniques.
Long-Term Development: Because of the evolutionary nature of the EvoHab structural system, over time the Asgard colony and sister settlements would be able to achieve vast habitat scales, transitioning through several scales of base structural components as on-orbit industrial capability grows in scale and sophistication. Communities of several hundred thousand residents are a possibility.
With the advent of nanotechnology will come some interesting variations on the structural system such as the creation of self-integrating hull modules which would allow for the three structural elements –frame, shield, and inner pressure hull substrate- as well as light-transmitting optical elements of the earlier EvoHab hull system to be combined into a single modular panel component which, when placed against its neighbors, automatically knits itself into a molecularly monolithic whole and would retain capabilities of self-repair. These components would also further enhance the light and image transmitting capabilities of the hull system to the point where it is truly virtually invisible from inside and out, finally achieving the seamless total transparency envisioned by Marshal Savage no matter how thick a hull structure is ultimately desired for a necessary safety margin. Struts of the space frames of the core truss structures would also see a growing integration of features, subsuming many of the utilities conduits that formerly were retrofit to it and adding such things as integral light emitters.
In general, nanofabrication will bring a progressive lightening, strengthening, and smartening of the components elements of the EvoHab, making them increasingly autonomously self-assembling and self-maintaining. This presents the possibility of a great leveraging of personal space development ability in conjunction with emerging asteroid exploitation capability. Perhaps compelled by some crowding of the original habitats, individuals and quite small family or cultural groups will take advantage of the newer structural component systems to produce equally large but far less dense habitats elsewhere in near-Earth orbital space or in true solar orbits, ushering in the Solaria phase.
With the ultimate advent of NanoFoam, sometime in conjunction with the Solaria phase of development, these habitats would assume a progressively more organic and contiguously integrated structure as contiguous NanoFoam structures subsume the modular elements of early structure. Depending on the aesthetic tastes of inhabitants, the urban tree structure of the habitat may assume a progressively more literal analogy, the symbiotic integration NanoFoam cybernetic support structure to living organic plant matter producing a very naturalistic looking and living tree structure that subsumes the earlier core truss structures. Ultimately, these Asgard phase habitats may become BioSphere habitats, as we will discuss later in the Solaria section.
- Life In Asgard
- Modular Unmanned Orbital Laboratory - MUOL
- Modular Unmanned Orbital Factory - MUOF
- Manned Orbital Factory - MOF
- Asgard SE Upstation
- Asteroid Settlements
- Inter-Orbital Way-Station
- Solar Power Satellite - SPS
- Beamship Concept
- Inter-Orbital Transport
- Cyclic Transport
- Special Mission Vessels
- Orbital Mining Systems
- The Ballistic Railway Network
- Deep Space Telemetry and Telecom Network - DST&TN
- Asgard Supporting Technologies