Workplan
Technical approach
The initiative started with a broad mapping of human needs, as shown for the first two levels of functional requirements in figure 1. This mapping will be carried through to include production processes at a scale that would fulfil "all human needs" in one self-contained manufacturing system. In order to encourage the development of new ideas, a "clean-sheet mindset" is required. Specifically, a moon colony completely cut off from terrestrial supplies but with its own production capabilities as required for indefinite survival, requires such a clear mindset for success. Although complete isolation in this initial phase is fictitious, the approach will ensure minimal supply costs, and experiences gained will be directly applicable to any large-scale lunar outpost. This idea is rapidly gaining acceptance in space agencies throughout the world, and has indeed been called for by the US Moon-Mars initiative announced by President Bush.
Figure 1: Survival requirement breakdown
The approach adopted will be a structured step by step requirement breakdown: In the first step, survival requirements and commodities will be identified and quantified for tracking through the production system, as tentatively shown in table 1. Of course, additional commodities will be identified and followed as the analysis progresses. We will specifically map the flow of all commodities, such as energy, raw materials and waste, without any reference to monetary cost. This approach of explicitly refraining from the use of monetary factors and influences is required in order to avoid complex considerations relating to the cost relationship determined by the supply and demand as well as the uncertain and shifting financial value of the various commodities.
Table 1: Preliminary material requirements breakdown: commodities (“I“ denotes that the commodity is required as Input to the process, “O” denotes that the commodity is produced as Output from the process.)
Once this foundation has been established, the production facilities needed to satisfy the survival requirements must be identified and defined followed by an investigation of the interconnections between the different processes. A rough production system flowchart is shown in figure 2.
Figure 2, Production system flowchart
The manufacturing process is seen as a crucial part of the overall survival system and will therefore be given particular attention in this project. Thus, prototype manufacture and testing will be performed to assess the feasibility of identified manufacturing systems, focussing efforts on metal components because of their higher near term spin-off potential. Experimental work will include some of the more promising methods for manufacturing a variety of shapes and materials from as restricted and limited amount of manufacturing tools as possible. This will include shaped metal deposition, a freeform production method employing welding, not for joining but for building complex components at very near net shape. Machining and grinding will certainly also be needed for high precision tolerances as and when that is required. Although possibly too complex for this application, thermal spraying is another process that is commonly used for adding layers of highly different properties to a metal component. Interestingly enough, the equipment for some thermal spray methods is very similar to the equipment used for related welding methods. Thus it should be possible to design dual use equipment that could be quickly adapted from welding to thermal spraying, and vice versa, as and when such a need arises. In this highly advanced process development research, it will be necessary to employ a mix of process knowledge, experimental measurement expertise and numerical simulations, as indicated in table 3. Incidentally, table 3 also shows the current expertise and research focus of the SMART-Centre at University West.
Table 2: Matrix of research disciplines applied to manufacturing processes
The manufacturing system will give further material requirements, such as equipment and raw materials. Versatile and flexible production system solutions will be required for the small community size studied, in order to avoid overly long chains of specific manufacturing equipment needed for the manufacturing of more advanced specialised manufacturing equipment.
Restrictions and limitations
The present aim of the initiative is to describe the manufacturing needs for a self-supporting, fully isolated community of 500 persons on the moon. With self-supporting, we understand that all material needs should be fulfilled using in-situ resources, mined and refined by equipment that does not require earth supplied servicing or spare parts. The reason for requiring complete isolation is for conceptual ease, and not that isolation is intended or foreseen.
The study will only address material survival needs, and not psychological or physiological difficulties caused by the isolation and extreme environment on the moon. The ecology of the life support system will not be addressed as such, although material needs of typical small scale farming will be included in the resource flow model to be derived. Further, manufacturing trials will be performed in Earth atmosphere only, and the low gravity and vacuum of the moon will only be included in parametric simulations.