"The solution to wind-shake of large telescopes was finally found at 10:00 in the evening of January 6, 1986 at Cafe American, San Francisco, over a cafe latte and a sturdy napkin."- Ethan W. Cliffton

The Fixed Shutter Dome (FSD), an enabling technology for all telescope enclosure applications, was invented by Ethan Cliffton following design work for the Keck Observatory where 110km/h winds were a limit on viewing in otherwise clear weather owing to telescope shaking. That limit may be exceeded with a sturdier windscreen. Multiple shutter segments, folding metal shields, and high-tech fabrics were reviewed and discarded in favor of structural protection. The Pic-du-Midi Observatory achieved this protection for its 2-meter telescope. However, the use of swinging doors at larger diameters, as occur in the new spuncast and meniscus mirrors, was unworkable.

The hard spacesuits developed by Vic Vykukal at NASA Ames Research Center used split spheres for body and limb joints. These joints typically open over more than half their diameter. The FSD synthesis arrived by applying the hinged sunshield from the spacesuit helmet to the chords of the split spheres. Reducing the working parts locked the shield, now the shutter, to the lower spherical segment, the antrum, kinetics defined the aperture, and the FSD was created.

Resolution of skin stresses into a series of rings resists deflection from wind, snow, or ice and puts robust structure between the telescope and the weather, even at the zenith. Dames & Moore have prepared an engineering analysis of the structural characteristics of a 20-meter diameter FSD.