UNIVERSITY OF CALIFORNIA OBSERVATORIES / LICK OBSERVATORY
|ALUMINIZING THE 3-METER MIRROR: FEBRUARY 2000
|Reinstalling the Mirror
|The newly coated mirror, again protected with a sheet of clear plastic, is carefully hoisted from the aluminizing chamber in the basement, through the hatch to the observing floor. Its cell, tipped upright on the mirror-handling platform, can be seen at the upper right.
|The mirror is brought into alignment with the waiting cell.
|Very slowly and carefully, the mirror is rejoined to its cell. The individual mirror supports must mate precisely to the miror's honeycombed back.
|With the mirror and cell rejoined, the mirror-handling platform is tilted back to the horizontal. The protective plastic sheet will be removed just before the mirror is replaced in the telescope.
Beneath the platform, the crew replaces the counterweight assemblies which support the mirror from behind.
At right, one of the assemblies is seen as it is jacked into place on the underside of the cell using a specially designed tool.
Each counterweight provides an upward force on the backside of the mirror. The amount of force varies with the angle of the telescope, ensuring uniform support no matter where the telescope is pointed.
|The lower end of the the telescope without the mirror and cell
|The telescope with the mirror and the cell just reinstalled. The TUB--containing the optical, mechanical, and electronic interfaces for instruments will be attached next, completing the four days' job of realuminizing the Shane 3-meter mirror.
|The aluminizing crew