The vast equatorial mariculture facilities of Aquarian sea colonies will be the primary breadbasket for the first generation of manned settlements of Asgard. (and much of the world, with any luck) With the advent of some scale of Bifrost Space Elevator helping to radically reduce transit costs, this may remain the case for well into the Asgard phase. But ultimately the sustained habitation of space will demand the development of in-space food production capability of great scale. Even if relying largely on terrestrial food sources, Asgard colonies will be charged with the task of cultivating this capability.
Many farming technologies are likely to be explored in this effort but we see two related concepts as particularly likely; the SkyGarden and SkyFarm.
SkyGarden is a hydroponics gardening system derived from pressurized nutrient film hydroponics techniques explored by NASA near the end of the 20th century. The key challenge for hydroponics systems in a microgravity environment is the efficient delivery of nutrient solutions to plant roots. But the behavior of fluids in microgravity is problematic, usually demanding the use of pressurized fluid transport and delivery.
Typical hydroponics relies heavily on gravity to control fluids. Aeroponics systems, which deliver nutrient in an air mist suspension, are less limited to gravity and can work with pressurized fluids but, in the absence of gravity, require complex methods of fluid recovery for the cycling of these misted fluids. These systems have been limited largely to seedling cultivation on Earth because of their complexity. They are likely to be similarly limited in space. However, one area of hydroponics –nutrient film technique– offers many possibilities because it relies on capillary action to distribute and recover fluids. With these types of systems simple flat polymer bag tubes with pockets for individual plants become a sufficient life-support system, making this one of the most common technologies for commercial-scale hydroponics. However, these systems too tend to rely on gravity recovery of flowing nutrient even if capillary action is supplying the roots themselves. In the 90s NASA explored (but, alas, never deployed…) an interesting variant of this technology based on the use of permeable membranes and ceramics. Used in tubular or channel shapes, these materials become permeable to fluids when under a certain level of pressure. By combining these materials with elastic sheathing to hold plant roots in place, a simple and highly efficient method of pressurized nutrient delivery and cycling becomes possible.
But what is particularly interesting with this technique is the way these rigid materials like ceramics can potentially provide a structural support not just for plants but for other components of a gardening system and the potential to employ them with many shapes and many forms of reinforcement materials to strengthen them. Exploiting this, it becomes possible to implement microgravity hydroponics garden systems based on various volumetric structural shapes of varying size which can not only physically support plants but also the many support components of a complete gardening systems. Thus we arrive at the concept of the SkyGarden; a space-frame-like structural system for microgravity hydroponics. SkyGarden would be composed of a system of modular components including a variety of pressure-permeable plant host shapes including tubes, rigid corrugated panels, balls-shaped nodes, and the like, non-permeable piping and structural supports, nodal couplers serving as both structural and fluid network couplers, and integrated systems components including pressurized nutrient management units, fluid storage tanks, lighting systems, sensors, and accessories like hand-holds and plant supporting frames, stand-offs, and tie-downs.
SkyGarden systems will likely see first use as laboratory gardening systems and then evolve to use as decorative gardening systems to enhance the quality of life in space habitats. Being able to integrate physically with major structural systems of the EvoHab type of settlement, extensive gardening structures may be deployed. Gazebo-like frame structures, added to some individual dwellings to afford casual access to the large open spaces of a habitat, may be based entirely on SkyGarden structures, turning homes into volumetric gardenscapes and making the idea of the Urban Tree habitat a very literal analogy.
The most elaborate and sophisticated use of SkyGarden systems would be as the basis of SkyFarms. These would be intensive farming facilities based on their own TransHab or EvoHab hull structure and a series of heliostat arrays gathering and conducting light into the habitat via fiber optic cables. Within these habitat structures large SkyGarden structural arrays would intersperse growing frames with fans, misters, and tubular light emitter arrays linked to the fiber optic light supply and supplemented by electric powered light pump units. The overall structures are likely to employ a prismatic array geometry, creating channels through the structure for human traffic and for the mounting of robots on simple role-like rails which would be used to automatically tend and harvest plants.
A very similar system would be employed for mass algaeculture with this potentially integrated into the same SkyFarm facilities. Light-weight culture tubes made of elastomeric materials integrating into the SkyGarden component system would host both ‘leaky fiber’ polymer light emitters within them, providing a continuous line of light throughout the length of a culture tubing array. Another similar approach may employ tubing made of optical polymers employing total-internal-reflection to conduct light from fiber cable couplers at intervals along their length throughout the tubing walls whose inner surface would be treated to be optically ‘leaky’, thus making the tubing itself a diffuse all-around light emitter. Most of these culture tubes would be opaque. Transparent culture tubes mounted in-line at intervals with the others would be used to visually monitor conditions in the system. This technology would also offer potential for integration into the multi-level composite hull structure of large EvoHab hulls, integrating into their all-over heliostat arrays to tap their excess sunlight and affording the hull technology the same integral algeaculturing capability that Marshal Savage envisioned for the original Asgard design.
- Urban Tree Housing Concepts
- Asgard Digitial Infrastructure
- Carrier Pallets
- WristRocket Personal Mobility Unit
- RocShaw Personal Mobility Units
- Pallet Truck
- ZipLine Tether Transport System
- MagTrack Transport System
- Meat Culturing
- Microgravity Food Processors
- Pools and Baths in Orbit
- Solar Sails
- Plasma and Fusion Propulsion