Characterization of superconducting bearings for lunar telescopes

The hybrid superconductor magnet bearing system for a lunar telescope has been developed based on passive magnetic levitation and the flux pinning effect of high-temperature superconductivity. The rationale lies in the unique capability of high-temperature superconductors (HTS) to adapt to the low temperature and vacuum environments in space or on the Moon, and to enhance system stability passively without power consumption. Characterization experiments have been conducted to understand its dynamic behavior and to estimate the required motor torque for its driving system design. Characterization experiments show that the hybrid HTS-magnet bearing system has periodical oscillation of drag torque. The bearing also suffers from small periodic oscillation on top of it due to discontinuous distribution of HTS. However, the magnitude of drag torque is velocity independent and very small. It makes the bearing attractive for high speed application. Finally, design guidelines for superconducting bearing systems are suggested based on experimental results.