The TMT enclosure has several key functions. By day, it must protect observatory systems, facilitate a broad range of maintenance activities, and keep the telescope temperature near the expected night time temperature. By night, it must shield the telescope from wind buffeting while allowing enough airflow to keep the interior iso-thermal to limit seeing degradation due to air turbulence in the enclosure.
TMT has selected an innovative, structurally efficient calotte enclosure design that, by its spherical shape and circular “shutter” aperture, fulfills key functional requirements with lower mass (and hence lower cost) than possible for previous enclosure designs.
