NASA Conference Publication 2255 Advanced Automation for Space Missions Edited by Robert A. Freitas, Jr. Space Initiative/XRI Santa Clara, California William P. Gilbreath NASA Ames Research Center Moffett Field, California Proceedings of the 1980 NASA/ASEE Summer Study sponsored by the National Aeronautics and Space Administration and the American Society for Engineering Education held at the University of Santa Clara Santa Clara, California June 23-August 29, 1980 N/\51\ National Aeronautics and Space Administration Scientific and Technical Information Branch 1982 For aale by the Superintendent of Document.., U.S. Government Printing Office, Washington, D.C. 2CK02 N83·15352 CHAPTER 5 REPLICATING SYSTEMS CONCEPTS: SELF-REPLICATING LUNAR FACTORY AND DEMONSTRATION 5.1 Introduction duplicates of itself which would themselves be capable of further replication. Successive new systems need not be As the cost of fossil-fuel energy continues to escalate exact copies of the original, but could, by remote design and supplies of readily accessible high-grade ores and min­ and control, be improved, reorganized, or enlarged so as to erals gradually become depleted, the utilization of non­ reflect changing human requirements. A few of the benefits terrestrial sources of energy and materials and the develop­ of a replicative growing lunar manufacturing facility (dis­ ment of a nonterrestrial industrial capacity become cussed at greater length in secs. 5 .4 and 5 .5) include: increasingly desirable. The Moon offers plentiful supplies (I) The process of LM F design will lead to the develop­ of important minerals and has a number of advantages for ment of highly sophisticated automated processing and manufacturing which make it an attractive candidate fac­ assembly technologies. These could be used on Earth to tory site compared to Earth. Given the expense and danger further enhance human productivity and could lead to the associated with the use of human workers in such a remote emergence of novel forms of large-scale industrial organiza­ location, the production environment of a lunar manufac­ tion and control. turing facility should be automated to the highest degree (2) The self-replicating LMF can augment global indus­ feasible. The facility ought also to be flexible, so that its trial production without adding to the burden on Earth's product stream is easily modified by remote control and limited energy and natural resources. requires a minimum of human tending. However, sooner or later the factory must exhaust local mineral resources and (3) An autonomous, growing LMF could, unaided, fall into disrepair or become obsolete or unsuitable for construct additional production machinery, thus increasing changing human requirements. This will necessitate either its own output capacity. By replicating, it enlarges these replacement or overhaul, again requiring the presence of capabilities at an increasing rate since new production human construction workers with the associated high machinery as well as machines to make new machines can costs and physical hazards of such work. be constructed. The Replicating Systems Concepts Team proposes that (4) The initial LMF may be viewed as the first step in a this cycle of repeated construction may possibly be largely demonstration-development scenario leading to an indefi­ eliminated by designing the factory as an automated, multi­ nite process of automated exploration and utilization of product, remotely controlled, reprogrammable Lunar nonterrestrial resources. (See fig. 5 .1.) Replicating factories Manufacturing Facility (LMF) capable of constructing should be able to achieve a very general manufacturing Figure 5.1.- Automated space exploration and industrialization using self-replicating systems. 189 capability including such products as space probes, plane­ Section 5 .4 deals with possible applications of the SRS tary landers, and transportable "seed" factories for siting concept. Applications of replication technology include on the surfaces of other worlds. A major benefit of repli­ enormous gains in terrestrial industrial productivity (auto­ cating systems is that they will permit extensive exploration mation and computer-aided design and manufacturing), and utilization of space without straining Earth's resources. utilization of Solar System resources, orbital and planetary opportunities, and the possibility of interstellar exploration 5.1.1 Summary of Chapter Contents on a grand scale. Indefinitely large masses can be organized in extraterrestrial environments using self-replicating The history of the concept of machine replication is systems. reviewed in section 5 .2. This theoretical background is Section 5 .5 deals with just a few of the many implica­ largely a consideration of the work of John von tions of SRS. The advantages of space-based replicative Neumann - in particular, his kinematic and cellular models manufacturing are considered, together with possible politi­ of automata self-reproduction. Post-von Neumann research cal, social, economic, cultural, and psychological conse­ is reviewed next, noting particularly the established theoret­ quences of the proposed SRS development program. ical capabilities of machines in the realm of general con­ Section 5 .6 sets forth in some detail how NASA can take struction, inspection, and repair strategies. Such strategies action at once toward the achievement of the ultimate goal may prove useful, even vital, to the successful design, of establishing a replicating manufacturing facility. Sug­ realization, and operation of actual replicating systems. gested statements of work (SOWs) and a listing of institu­ Section 5 .3 deals with the engineering feasibility of the tions that might undertake the tasks outlined in the work concept of self-replicating systems (SRS). An attempt is statements are included. A series of specific conclusions and made to confront two important general problems in creat­ recommendations generated by the Replicating Systems ing a lunar replicating factory: Concepts Team are presented in section 5 .7. • Given that in theory, machines can construct dupli­ cates of themselves, how might systems designers and 5.2 Theoretical Background engineers identify all functions which must be carried out to achieve machine replication and also develop The notion of a machine reproducing itself has great the technological means by which to implement these intrinsic interest and invariably elicits a considerable range functions? of responses - some directed toward proving the impossi­ bility of the process, others claiming that it can be carried • Given the constraints obtaining in the lunar environ­ out, but almost all of them indicating an unwillingness to ment, particularly in terms of the inventory of known subject the question to a thorough examination. In discuss­ kinds and quantities of naturally occurring raw ing self-replication by automata it is essential to establish materials and the existing repertoire of materials early rather important ground rules for the discussion. processing technologies, can all machine functions According to Kemeny (1955), "If [by 'reproduction'] we required both for production and for replication and mean the creation of an object like the original out of growth be implemented? nothing, then no machine can reproduce - but neither can To attack the first of these problems - identification of a human being .... The characteristic feature of the reproduc­ necessary functions for practical machine replication - the tion of life is that the living organism can create a new team proposes a specific phased demonstration­ organism like itself out of inert matter surrounding it." development scenario, described in section 5 .3. For the Often it is asserted that only biological organisms can second problem - establishing that machine replication can reproduce themselves. Thus, by definition, machines cannot feasibly take place in the actual lunar environment - a carry out the process. On the other hand, others argue that strawman mission concept was employed. In this scenario, a all living organisms are machines and thus the proof of 100-ton initial "seed" factory is planted on the Moon with machine reproduction is the biosphere of Earth. Also, access only to local resources and established materials sometimes it is claimed that although machines can pro­ processing techniques. The initial system should be able to duce other machines, they can only produce machines less successfully develop into an expanded machine system complex than themselves. This "necessary degeneracy" of capable of conducting all functions necessary for autono­ the machine construction process implies that a machine mous replication, growth, and automated production and can never make a machine as good as itself. An automated manufacturing. assembly line can make an automobile, it is said, but no The problem of "closure" is also considered at length in number of automobiles will ever be able to construct an section 5 .3. The issue of closure is whether autonomous assembly line. manufacturing and construction systems can make available Another common argument is that for a machine to to themselves all of the materials, parts, and assembly tech­ make a duplicate copy it must employ a description of niques required for all internal operations. An iterative itself. This description, being a part of the original machine, strategy is presented for detecting and eliminating closure must itself be described and contained within the original