Manufacture of 8.4 m segments for the GMT primary mirror

The Richard F. Caris Mirror Lab at the University of Arizona continues production of 8.4 m lightweight honeycomb segments for the primary mirror of the Giant Magellan Telescope. GMT will have a center segment surrounded by six off-axis segments, plus an additional off-axis segment to allow continuous operation as segments are removed for coating. The second off-axis segment was completed and accepted in 2019. We are currently polishing the optical surface of off-axis Segment 3. We have completed work on the rear surfaces of Segment 4, the center segment, and offaxis Segment 5. We are assembling the mold for off-axis Segment 6 with the spin-casting scheduled for March 2021.

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