Liquid Mirror Telescope 1995

The photo shows the bottom
of the liquid mirror telescope
with a close view of the air bearing.

The University of British Columbia Liquid-Mirror Observatory was established in 1995 to facilitate the development and testing of liquid-mirror telescope technology. The observatory houses the Large Zenith Telescope. The 19-foot diameter primary mirror of this telescope is one of the largest optical telescopes in the world, and the largest to use liquid-mirror technology. Paul Hickson of the University of British Columbia contributed to the development of the Next Generation Space Telescopes and is involved in the development and application of liquid mirror technology.

A key component of a liquid mirror telescope is the air bearing spindle that supports the liquid mirror. At the request of Paul Hickson, Professional Instruments Company developed this spindle. The model 23R BLOCK-HEAD® air bearing spindle is made from stainless steel and weighs almost two tons. The bearing surfaces are machined to microinch precision. The 23-inch diameter spindle can support a 10-ton load. A built-in brushless-DC motor rotates the 10-ton load at approximately 10 rpm. An optical encoder provides feedback to the control system. With closed-loop control, the rotation speed can be precisely controlled to within one part per million.