the two classes into one will becombineddeviceinactualSuchcouldbechar practice.acombinationacterizedasaremote free-flying teleoperator equipped with a highly specialized manipulator of the general-purpose or spacecraft-services system type. An extension can be envisioned as a teleoperator vehicle combined with single or multiple manipulator arms used to align and attach beams in direct support of space construction activities. Depending on the complexity of the task at hand it may be necessary for humans to be directly in charge in a master-slave relationship and be housed in a life support module on the free-flyer. The next logical development step delegates this function to a manlike robot, thus freeing the system to work autonomously at extended operational ranges without the cumbersome remote or local presence of man. In the reference Space Manufacturing Facility developed by Miller and Smith (1979), the large number of similar components in the solar-cell factory and the X-ray environment precludes direct human labor. This suggests automated maintenance and repair, so the solar-cell factory was designed for tending by automated and remote devices. A free-flying hybrid teleoperator (FHT) can do on-site repairs at the solar-cell factory. The FHT can be operated either fully automated (tied into an AI-capable computer system or using preprogrammed routines), automatically with human override, or fully remote-controlled by a human operator (teleoperation). Free-flying teleoperators or robot servicing units will have the capability to autonomously rendezvous, close, and attach to a satellite, first in LEO near the main station and later in GEO (Schappell et al., 1979). In some cases satellite retrieval, rather than servicing, will be desired. This would be a precursor to automated asteroid retrieval missions, requiring completely autonomous systems for navigation, guidance, sensing and analysis, attachment, and mining (Shin and Yerazunis, 1978). On-board and free-flying teleoperators will be required throughout the postulated mission plan. They will extend man's senses and dexterity to remote locations while the human supervises and controls from a safe, comfortable environment. Teleoperators are a logical step in the evolution to fully automated (robot) systems needed for efficient extraterrestrial exploration and utilization. Previous sections have already discussed the role of man, the role and configuration of such teleoperators, and the role and development required for completely automated, possibly self-replicating, systems.
6.5.2 Teleoperation Sensing Technology The uniqueness and utility of teleoperators lies not in their mode of locomotion, but rather in the "telepresence" they provide -the ability of the man to directly sense and remotely affect the environment (Minsky, 1980). Sensor and manipulator technology is advancing apace, largely through rapid growth in the fields of industrial robotics and computer science. Approximately 40% of human sensory input is in the form of vision, so it is appropriate that most work in physical perception relates to visual information processing and remote scene nterpretation. Algorithms and specialized sensors developed for satellite on-board pattern recognition and scene analysis can enable the teleoperator to perform many of these functions. Teleoperation has several unique characteristics such as viewing and working in three dimensions under variable conditions of scene illumination, and options of wide or restricted fields of view. Three dimensional information can be obtained from stereo displays (Chin, 1976; Duda and Hart, 1978; IEEE, 1979), lasers (Shin and Yerazunis, 1978), planar light beams (Baum, 1979), radar and proximity sensors (Schappel et al., 1979), or it may be recovered from two-dimensional pictures (Tenenbaum, 1979). Besides its use in autonomous tasks, a computer "world model" can be utilized in two ways. First, it can provide the man a computer-generated display from any point in the "world." Theoretically, from an overall view of the entire scene (including the teleoperator itself) the camera eye could zoom down inside a crevice or behind an object. Using data from a scanning laser ranging system, the system described by Shin and Yerazunis (1978) could construct a perspective model of nearby terrain and superimpose the route through the terrain determined by an optimal path selection algorithm. Second, using camera location as a reference point and overlaying the "world model" over the camera picture would permit correlation of the world model with the real world, thus enabling the operator to immediately detect anomalies or inaccuracies in the knowledge base. This "knowledge overlay" would allow corrections for sensor errors and keep autonomous manipulator operations properly referenced. Without such a knowledge overlay the man is severely handicapped in acting as supervisor of largely autonomous operations. Besides vision, a teleoperator should give the human a "feel" for the task. Minsky (1980) notes that no present system has a true sense of feel, and insists that "we must set high objectives for the senses of touch, texture, vibration, and all the other information that informs our own hands." In addition to communicating via sight and touch, an audio interface between man and computer also is feasible (see section 6.5.3). Voice input/output systems are commercially available and in use. Research continues, though, in artificial intelligence and computer science on natural language understanding, faster algorithms, and connected speech processing. However, it should be noted that teleoperators with simple bilateral force reflection can achieve most immediate goals in space. These were demonstrated by Ray Goertz as early as 1955, and can be used now.
