60-inch Aluminizing

This week we are re-aluminizing the mirror for our 60-inch telescope. As you'll see below telescope mirrors can get dirty over time. Even with a weekly spraying of CO2 to remove dust, it is eventually time to give them a good washing, strip off the old coating of aluminum and apply a new one.

The process began early yesterday morning with the removal of the science instrument and other components of the telescope. The telescope has a light baffle directly over the primary mirror which needs to be removed before the mirror can be taken out. Members of the staff have to carefully work inside the telescope tube to remove the baffle.


Here's a view from inside the telescope (taken from between the primary and secondary mirrors) looking down at the primary mirror.
The telescope is then brought into the vertical position and locked into place. A cart, made just for this purpose, is moved into position and raised to the back end of the telescope.

The mirror is then unbolted from the telescope and the cart, with its precious cargo, is then carefully lowered.Here is the mirror, safely removed from the telescope and the mirror cell. As you can see it is time to clean it up.

The rest of the process takes place in the dome of 200-inch telescope. In the next post I'll cover transportation, washing, stripping and re-coating the mirror.