The Gemini North enclosure (left) shown with the crane used for the recent installation of the service platform. This platform will be necessary to make repairs to the failed shutter bearing. Inset shows a closeup of the shutter bearing assembly with the skewed assembly (aqua, at bottom). Because access to the assembly is not possible when installed on the dome, this entire assembly, weighing about 4200 pounds, must be removed and will require the use of the same crane used to install the service platform.

The shutter opening system of the Gemini North enclosure has suffered a catastrophic and unexpected failure (see Figure). Access to the components within the drive box is difficult, and special tools and parts have to be fabricated. It is expected that the repair will be completed by January 24th, however it may take longer if there are prolonged periods of bad weather which prevent access to the system, which is located on the dome exterior.

During this forced shutdown, we will carry out the planned repair of the GMOS-North on-instrument wavefront sensor, and we are looking at pulling forward other engineering maintenance tasks that can be performed simultaneously, to make best use of our time off the sky. The shutter system for the Gemini South enclosure is being examined for any indications of a similar failure.

Updates will be provided here, via email to active Gemini investigators, on the Gemini website, and the Gemini Facebook page, as available.