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 to NASA necessary technologies,pathofrobotics. And theevolutionary Teleoperators have been developed to expand man's physical capabilities across great distances and in hostile or inaccessible environments. Typical applications include (1) safe, efficient handling of nuclear or toxic materials, (2) undersea mining and exploration, (3) medical and surgical techniques, and (4) fabrication, assembly, and maintenance on Earth and in space. An artificial limb is considered a teleoperator because it restores lost dexterity to an amputee. Teleoperators are not new. In 1954 Argonne National Laboratory developed a master/slave hand system with force feedback via cables and pulleys. In 1958 William Bradley (1980) operated an area-of-interest television camera system mounted on a truck to provide a display to the "driver" located 15 km away. In the 1960s General Electric engineers designed "Hardiman," an exoskeletal teleoperator with 15 degrees of freedom and the capability of manipulating 700-kg loads with ease (Corliss and Johnsen, 1968). Research is progressing once again in manipulators, sensors, and master/slave systems. Further technology advances will be made as NASA develops teleoperators for space operations.

6.5.1 Teleoperator Applications Advanced teleoperators for future space missions present new challenges in the development of spaceborne manmachine systems (Bejczy, 1979; Bradley, 1967; Corliss and Johnsen, 1968). Teleoperators are robotic devices having video or other sensors, manipulator appendages, and some mobility capability, all remotely controlled via a telecommunications channel by a human operator. The man can exercise direct in-the-loop control using a joystick or other analog device, or can choose more indirect means of command such as an AI system in which he shares and trades control with a computer (NASA Advisory Council, 1978). Heer (1979) estimates that flight demonstrations of automated Shuttle manipulators can begin as early as 1982, for automated construction devices in 1986, and for a free flying automated teleoperator by 1987. A teleoperator will be on the first operational Space Shuttle flight. The Shuttle has a six-degree-of-freedom general-purpose Remote Manipulator System (RMS) with a 15-m reach (Meade and Nedwich, 1978; Raibert, 1979). The RMS lifts heavy objects in and out of the payload bay and assists in orbital assembly and maintenance (Meade and Nedwich, 1978; Raibert, 1979). An astronaut controls the rate of movement of the RMS using two three-axis hand controllers (Lippay, 1977). One proposed follow-on is installation of a work platform so that the RMS could be used as a "cherry picker," carrying astronauts to nearby work sites. One RMS will be mounted on the port longeron with provisions for a second RMS mounted on the starboard side. Conceptually the RMS arm is much like a human ann, with yaw and pitch at the shoulder joint, pitch at the elbow, and yaw, pitch and roll at the wrist (Lippay, 1977). The upper arm is 6.37 m long and the lower arm is 7.06 m long, providing a 15-m reach. The RMS can move a 14,000-kg payload at 6 cm/sec with the arm fully extended, or up to 60 cm/sec with no load (Space Shuttle, 1976, 1977, 1978). Two other distinct classes of teleoperation will be required for complex, large-scale space operations typified by the space manufacturing facility described in chapter 4. The first is a free-flying system which combines the technology of the Manned Maneuvering Unit with the safety and versatility of remote manipulation. The free-flying teleoperator could be used for satellite servicing and for stockpiling and handling materials (Schappell et al., 1979). Both of these operations require autonomous rendezvous, stationkeeping, and attachment or docking capabilities. Satellite servicing requires the design of modular, easily serviceable systems and concurrent development of teleoperator systems. The Teleoperator Maneuvering System (TMS) is an unmanned free-flying spacegoing system designed to fit in the Shuttle Orbiter, with the capability to boost satellites into higher orbits, service and retrieve spacecraft, support the construction assembly and servicing of large space platforms, capture space debris, and perform numerous other tasks in orbit. TMS has the potential, with developing robotics technology, to greatly extend and enhance man's capabilities in space. As presently defined by NASA, TMS is propelled with hydrazine or cold gas thrusters, controlled by operators at ground stations or in the Orbiter's aft flight deck, and can be placed under automated control using its onboard computational capabilities. TMS eventually will be equipped with antennas, manipulators, video equipment, dexterous servicing mechanisms, a solar power array, and other equipment as needed to position spacecraft, rendezvous with and service satellites, position large platform sections, and act as a "smart" free-flying subsatellite for performing specialized missions. It can perfonn all known LEO payload retrieval missions within 1 km of the Shuttle, and retrieval at distances of 800-1600 km from the Orbiter could be demonstrated by the mid-1980s (OAST, 1980). Manufacturing processes and hazardous materials handling may utilize mobile or "walking devices," the second distinct class of teleoperators. The teleoperator would autonomously move to the desired internal or external site and perfonn either preprogrammed or remotely controlled operations. For manufacturing and repair, such a system could transport an astronaut to the site and the manipulator could be controlled locally for view/clamp/tool operations or as a workbench. Of course, the size and level of teleoperator mobility (free-flying or walking) is dictated by mission needs. Probably