Gemini Telescope Enclosure

Challenge

As telescopes get larger it becomes more challenging to protect them from the environment. To ensure thermal stability of a telescope structure and its components, it is necessary to hold an enclosures internal temperature within very fine limits during daylight hours. Before the telescope is operational, it is desirable to create a thermal balance by allowing ambient air to circulate around the telescope structure, thereby purging the enclosure. During this phase, the telescope should be exposed to as much nighttime air as possible. The challenge was to design an enclosure structure that could protect the telescope during the day yet open up during the night to allow purging.

Solution

We designed large vent shutter doors, which exposed 40% of the enclosure surface, to open and allow ambient air to encircle the telescope structure and assist in the purging process. The doors were manufactured using both aluminum and fiberglass to protect against high degrees of solar radiation. To minimize driving loads and gravity effects, the upper and lower shutters were mechanically connected. Special stainless steel and teflon bearings formed the vertical tracks. The enclosure structure was designed to support these large openings while preserving stiffness and stability.

"I have appreciated the very real intellectual interest demonstrated... Our relationship has been the most positive that we have had with any outside fabricator"

Nick Scoville, Director, Owens Valley Radio Observatory