Page:Advanced Automation for Space Missions.djvu/362

 research.candidateand A secondprojectisthefabricationassemblyforuseinlargecon of abeam-builderstructurestructionexperiments.These two machine tool projects could then be combined to study materials handling and storage problems by having the first project provide feedstock for the second. Additional experimentation on producing feedstock from lunar materials would be a logical outgrowth of this development. While the space manufacturing experiment station is largely viewed as an experiment station for capital equipment production and as a stepping stone to the establishment of a lunar manufacturing facility, it should be noted that the station can also be used for biological research and the preparation of products such as drugs and medicines for terrestrial consumption. For example, many pharmaceutical components require a zero-g environment for their separation. Additional products for terrestrial consumption would be perfect spheres or flat surfaces made by joining bubbles. The technology required for permanent facilities to process nonterrestrial materials on the lunar surface or elsewhere lies far beyond currently proposed space materials processing capabilities. Numerous workers have suggested processes such as electrolysis, hydrogen fluoride leaching and carbochlorination (see section 4.2.2), which are adequate for short-term usage but cannot reasonably be expected to meet long-term growth requirements. Processes must be developed which yield a far broader range of elements and materials, including fluorine, phosphates, silica, etc. Volatiles such as water and argon, and desirable rock types such as alkalic basalts and hydrothermally altered basalts, could be acquired as a result of lunar-surface exploration. High-grade metals can probably be retrieved from asteroids in the more distant future. Sophisticated and highly automated chemical, electrical, and crystallization processing techniques must be developed in order to supply the wide variety of required feedstock and chemicals. Some possible solutions may be generated by studying controlled fractionation and chemical doping of molten lunar materials in order to achieve crystallization of desired phases. Zone refining and zone melting techniques may ",also be fruitful areas for investigation. New oxygen-based chemical processing methods should also be examined.

6.4.3 Technology Requirements The control of individual machine tools has continued to advance in feedback and feedforward control modes. The control of a diverse, highly integrated industrial complex requires advances in computer systems. High-speed data access in linked hierarchical computer networks will be needed. These computers will require coordination in real time. For example, the material handling computers must relay messages to the material handling devices telling them which machines need to be emptied or loaded and the material handling devices must know where to place the removed product. Advances in autonomous planning and scheduling in a dynamic environment are required, using new scheduling algorithms and shop floor control techniques. Large database requirements will soon become apparent. Repair robots must have the capability to hypothesize probable causes and sources of malfunction. The establishment of space or lunar manufacturing facilities require the development of the following technologies: • Basic research on materials processing in the space environment • hnprovement in primary shaping technologies of casting and powder processing for metals and nonmetals with emphasis on the economic elimination of manual mold production, possibly by the use of containerless forming • Improvement in heat dissipation abilities in relation to the tool/chip interface in space, and control of cooling rates in castings • Comprehension of cold-welding as a limiting factor for metal curing and as a joining technique • hnprovement of robot dexterity and sensors (especially vision) • General and special purpose teleoperator/robot systems for materials handling, inventory control, assembly, inspection, and repair • hnprovement in computer control of large, integrated, dynamic hierarchical systems using sophisticated sensory feedback • Study and inlprovement of lasers and electron-beam machining devices • Embodiment of managerial skills in an autonomous, adaptive-control expert system

6.5 Teleoperators and Robot Systems A teleoperator is a device that allows action or observation at a distant site by a human operator. Teleoperators represent an interim position between fully manned and autonomous robot operation. Teleoperators have motor functions (commanded by a human) with many possible capabilities, and have sensors (possibly multiple, special purpose) to supply information. The human being controls and supervises operations through a mechanical or con> puter interface. As technology advances and new requirements dictate, more and more of the command and control functions will reside in the computer with the man assuming an increasingly supervisory role; as artificial intelligence methods are developed and are applied, the computer eventually may perform "mental" functions of greater complexity,makingthesystemautonomous. moreThefollowingdiscussionconcernsteleoperators andtheirfunctions, applicationsprograms,supporting