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A lunar telescope to be built in the near future must be able to operate for long periods in a cold, dusty vacuum environment without on site human maintenance. The slow rotation rate of the moon requires a drive mechanism with exceedingly fine steps. Both these requirements are difficult, if not impossible, to meet with conventional motors and gear drives. The recently discovered high temperature superconductors (HTS) offer an attractive and practical solution. By using a combination of HTS and permanent magnets, hybrid superconductor magnet bearings (HSMB) can be made that are stable, small in mass, passive (i.e. no power required to maintain configuration), and essentially frictionless. Since there is no mechanical contact between the rotor and stator in a HSMB, the bearing does not wear out with use and requires no maintenance. The very low friction in a HSMB permits electronic positioning control with exceedingly fine resolution. Work is currently in progress at NASA/GSFC, U. of Houston, and elsewhere to produce a working telescope model with HSMBs. We demonstrate the operation of a HSMB to show that currently available HTS materials can already meet the requirements for lunar applications. We discuss the workings of a HSMB, cooling requirements, and the effect of long term radiation exposure on HTS.
