The Gemini South maintenance shutdown began on 2 October 2023 and is expected to continue through 11 November 2023. This planned shutdown will involve several critical tasks, including stripping and recoating the primary mirror of the Gemini South telescope, replacing aging helium lines in the Cassegrain wrap, and addressing various essential maintenance issues in both the telescope and its subsystems. The Gemini South primary mirror has not been recoated for eight years, resulting in a decrease in reflectivity. The application of a new protected silver coating during this shutdown is expected to extend Gemini South's main mirror's operational life by at least 5 years.
To ensure the safety and success of the complex mirror coating process and maintenance work on the telescope and subsystems, the shutdown will begin with work on the Acquisition and Guiding subsystem, as well as the replacement of helium lines. This initial phase is estimated to take approximately two weeks. Subsequently, the stripping and coating process of the primary mirror will commence.
This extensive effort will involve collaboration across NOIRLab, with contributions from the Gemini South Engineering team, select members of the Gemini North Engineering team, and personnel from NOIRLab Engineering Services and Mid-Scale Observatories.