been shown at all. The assembly of structures more massive than a space elevator would likely involve a combination of new engineering techniques, new materials, and new technologies. Such massive construction projects might require the use of self-replicating machines to provide a suitably large "construction crew". The use of nanotechnology might provide both the self-replicating assemblers, and the specialized materials needed for such a project. Nanotechnology is, however, another area of speculative exploratory engineering at this time. See also Kardashev scale Macro-engineering Space manufacturing Stellar engineering References Megastructures Engineering projects Exploratory engineering