Coping With Distance
Initially, Transport Rover robots would be the primary means of moving goods and materials about the telerobotic outpost. But as the outpost evolves toward permanent settlement and seeks out raw materials across progressively larger areas it will become impractical to employ such telerobots for bulk transit, particularly for the large volumes of raw material a settlement will ultimately need as it establishes materials self-sufficiency. Key materials collection sites will need outposts of their own and with continuous transit links to the primary settlement. Though likely to be semi-automated, the normal telerobots will still require routine monitoring and control by operators on Earth. This becomes impractical when the number of robots technicians must monitor becomes large. Similarly, the cost of individual telerobots is still relatively high and large numbers of them may not be cost effective for simple transportation tasks. Diverse self-adaptive automation that can largely eliminate teleoperation will require future advances in artificial intelligence, currently still speculative, thus simpler methods of automation would be needed to reduce teleoperation overhead. This is simple for stationary systems, but problematic for self-mobile machines in a distant and rugged environment. For long distance transportation the obvious approach is to limit motion along a transport route in such as a way as to reduce the parameters of control and the most common approach to that is some kind of track or rail. Thus a logical solution to this long distance transportation issue will be the use of various formed of tracked vehicles. In this section we will discuss some of the more likely forms of long distance automated transportation systems that may be deployed by the telerobotic outpost.
V-Track stands for Virtual Track and would be one of the simplest approaches to automating transportation based on increasing the autonomy of Transport Rovers and other robots. The V-Track system would be based on defining guideways using small radio trail markers placed along a transit path or a radio guide cable buried in the ground at a shallow depth along the desired transit path. This is actually a quite old technology, used, in various forms, in industrial automation for decades. V-Track would allow telerobots actively guided to path access points to be given a target destination to which they could then travel autonomously following the guideway signal and using simple collision avoidance sensors. This technology would be very flexible, allowing a diversity of robots to employ the same guide system and with pathways easily changed as needed. It is likely to be a standard feature of initial outposts, a standard feature of Road Tiles, and a key way of defining transit routes to initial satellite facilities. However, it does not reduce the costs and complexity of individual transport vehicles and would become less cost-efficient as the number of transit vehicles increase.
The Banana Monorail
Originally invented and patented in 1975 by Richard P. Carroll of Hydrolic Services & Engineering Inc., The Banana Monorail would be one of the simplest tracked transit systems the telerobotic outpost might deploy. Named for the simple monorail systems commonly used for agricultural purposes, its basic components consist of light alloy arches in the form of a self-standing bent/curved ‘X’ or ‘)(‘ shape installed on the exposed ground with screw pilings and supporting a thin alloy rail or wire on which simple carriages are hung from small bogeys. These bogeys can be individually motorized if their payloads are relatively light or more powerful ‘tractor’ units can be employed to tow trains of carriages. Systems can be based on stored power or distributed power using a second suspended power wire accessed with
a small pantograph arm attached to the bogeys. Simple arch shelters can combine with the arched support structures to provide partially enclosed station points. The Banana Monorail would be a modest scale system, its arch supports only a couple meters tall (except for extended sizes used to bridge variable terrain) and its carriages about the size of a cargo pallet or pallet-container suspended on one or two poles and bogeys. Carriages would be specialized in design, particularly for applications like carrying ore and granular materials where a tilt-bucket would commonly be employed. The system would be quite economical –one of the reasons it has become so commonly used on Earth- simple enough for relatively easy robot construction and service, and easily automated but somewhat limited in speed and flexibility. It’s not suited to complex route switching (agricultural version normally do not use switching), would not be able to transport larger robots except as parts, and is not likely to be adapted for passenger transportation. Still, as the most easily deployed form of long distance automated transit, this is likely to be key to early resource exploitation efforts
Automated Rapid Transit
Many settlements in TMP would implement forms of Personal Rapid Transit; automated transit systems based on simple cabs designed to integrate tightly into architecture, elevator systems, industrial production lines, containerized cargo handling systems, and Personal Packet Transit systems. Thus it’s likely that this same technology would find its use in Avalon as well.
The Avalon ART system would be a single or dual ‘U’ track supported system using modular prefabricated guideway supports and quick-connecting track segments. Supports would be as simple as a deployable leg ‘spider’ placed low on the ground, Road Tiles with ‘U’ Track attached sometimes used as short bridges, pilings supported structures of various heights, and modular space frame structures used as alternatives to spider supports or as large bridges. It may also support an overhead-suspended operation mode for some special applications and would integrate to both IWP and ISC robotics platforms. The base drive unit would consist of a breadboard style robot chassis similar to that used by many Avalon robots about the area of a mini-van or kai-van wheel-base with drive bogeys on the bottom, sensor and control electronics in its edges, and a variety of plug-in carrier and cab components similar to those used with the flatbed Transport Rover. Drive units would typically be used individually but, again like the TR, would be able to be linked in pairs or trains to support carrying of larger payloads, containers, and structures, though only along routes where the guide ways support the necessary clearance and wide turn radius's. By the time of Avalon, drive systems may be capable of supporting magnetically levitated linear motor systems rather than the more currently typical (if any PRT technology can be called ‘typical’ since so few are actually deployed after a century of development…) electric motor drives using polyurethane wheels. This innovation would enable sophisticated switching and very high speeds, potentially as high as hundreds of kilometers per hour.
ART is likely to be the mainstay surface settlement automated transit technology employed both externally over long distances and internally within the confines of the excavated habitats. It would work in, and be able to transition between, pressurized and unpressurized environments and support the maximum diversity of applications thanks to its easy integration to other robotic systems. Still relatively modest in carrying capacity, it would be large enough to carry larger rover robots and whole cluster outpost modules. As a passenger transit system, it would support simple light cabs capable of elevator-like door-to-door transit as well as larger pressurized cabs with their own life support systems and air-lock docking systems arrayed at any of 5 possible sides. It would also support use of a pressurized channel system where trenches for the guide way are dug along the desired transit routes, alloy arches then placed inside and buried to create a tunnel, and pneumatic tunnel units inflated inside with a Road Tile deck installed to support the guide way tracks. Automated airlock doors would compartmentalize the pressure containment along the routes and surface access airlocks would be installed at intervals. Later such channels would be created using prefabricated impermeable regolete modules with self-sealing joints and tracks pre-installed, these pressurized guideways progressively obsolescing surface guideways and creating options for secondary settlement construction along their paths.
Just as the flat bed TR has potential use in teams as the basis of a mobile launch and landing pad structure, so too would the ART drive technology, allowing for the use of multi-track supported mobile platforms and enclosures of large area, creating potential for large Vehicle Service Structures, both unpressurized and pressurized, in support of space transit. It may even find itself used as the basis of astronomical interferometer arrays and large space communications antenna structures.
Evacuated Tube Network
The ETN would be the Avalon equivalent of the Circum-Equatorial Transit Network described for the Aquarius phase and would share many of its characteristics. It would be the most advanced and longest distance automated transit system ultimate deployed by Avalon settlements and may be the focus of continuing development work for centuries beyond initial settlement. It would be based on the use of unpressurized subterranean tunnels hosting a high speed maglev shuttle system using relatively large pressurized cabs and unpressurized carriages closely matched in form-fact to the geometry of the tube-way.
On Earth the notion of long distance subways is generally considered impractical due to the extremely great labor and time necessary for excavation. On the Avalon settlement, however, this strategy makes great sense as a practical way to maximize the use indigenous resources in their simplest forms and minimize the need for refined materials by minimizing active track hardware to relatively small retrofit modules, though ultimately this transportation system would only be feasible long-term with the advent of local industrial capability for most of its manufactured components. For passenger transit, it’s also necessary to minimize radiation exposure over frequent long distant transit and for system automation it is necessary to control the environment around a transit system as much as possible. By placing a system in tunnels, natural rock strata would provide the primary track structure and would isolate that track completely from the ambient environment, minimizing and simplifying maintenance, while totally confining movement of vehicles to the path of the tunnels and allowing for higher speeds with higher safety. Long construction times would still be an issue even with automation given current technology, but as the technology of automated excavation improves, largely with the impetus created by Avalon settlement, increasingly rapid construction rates would develop, particularly given the advent of nanotechnology as a ‘frictionless’ means of excavation.
The ETN system would use simple unpressurized tunnels –rock, lined, or based on prefab regolith segments in loose granular strata or across exposed bridged sections- retrofit with linear motor drive elements and associated system hardware. Tunnels could be round or square in profile and have pressurized service bunkers with surface access at intervals. These service bunkers would also likely be associated with distribution power facilities at the surface.
The system would support carriages based on a standardized open space frame chassis –thanks to the lack of air, dust, and weather- very closely matched to the profile of the tunnels. These could be as large as 9 meters high and wide and in varying lengths. Though quite large, these vehicles would be remarkably light compared to conventional railway cars owing to the efficiency of linear motor systems and the light space frame construction. Cargo decks or slide racks would be added to the bare chassis for transport of containerized cargo and could be accessed from the ends or the sides. Others may be specialized to particular cargoes, especially bulk gasses and fluids.
A passenger cab would be made by combining the space frame chassis with a tough pneumatic pressure hull outfit much like many vehicles and utility habitats in the Asgard phase with an internal framing system hosting partitions, finishing panels, and furnishings. Cylindrical in form, it would likely feature end-mounted pressure doors. Sophisticated life support systems would be included as well, making the cab into a veritable spacecraft that, in an emergency, could support passengers for extended periods. Three types of passenger cabs are likely; a short one outfit like a commuter transit vehicle used for short trips, a ART integration carriage that can carry drive-on pressurized ART cabs, and a longer one designed for extended trips and outfit like a cruise liner cabin or recreational vehicle, complete with toilet and bathing facilities, bedding, lounge, entertainment systems, and robotically pre-stocked kitchenette. This parallels the design of rail cabs used in the Circum-Equatorial Transit Network and like that system would function in a dynamic-destination mode more akin to a Personal Rapid Transit system than a conventional ‘train’.
With the advent of more advanced excavation technology, carriages could also be designed as complete tunneling systems, with tunnel boring and InchWorm based track assembly combined in a standard carriage chassis and linking to materials removal carriages. These would afford tunnel construction with little other additional equipment and possibly without much human supervision given the telerobotics advances achieved in early settlement development.