SSO News

Published in the RSAA Lunations
Vol1 Issue16 1–31 May 2021

Every 12 months, the 16-tonne mirror of the AAT receives a fresh coating of aluminium. It is a lengthy process: the Cassegrain cage, instrument and A&G unit are removed first, the mirror cell is then removed, the mirror is taken out of its mirror cell, the old coating is removed, the mirror is prepared, and a fresh coat of aluminium is applied. The mirror then has to be placed back into the telescope and the telescope tested. We assign 5 days to aluminise the mirror, but SSO staff usually do it in 4 days. This time round they did it in 3!

A picture of the mirror with the coating removed, as it was about to be placed in the aluminising tank. A picture of the freshly coated mirror 24 hours later with very happy SSO staff.

Chris Lidman on behalf of the team at SSO