Mount Hopkins, AZ

Smithsonian Institution, Multiple Mirror Telescope


With the advent of economical large spun cast mirrors, the Smithsonian Institution and the University of Arizona wished to convert the Multiple Mirror Telescope (MMT) to a telescope with a single 6.5 m dia. mirror to retain its position as one of the world’s most powerful instruments.  SGH developed the drawings and specifications for this modification.

Highlights of SGH’s work on this project include the following:

  • Developed conversion concepts and the final designs of the new Optics Support Structure (OSS) and mirror cell structure
  • Designed a system that allows for in-place aluminizing of the primary mirror by lifting in a vacuum head and using the mirror cell as the bottom part of vacuum chamber
  • Designed the required modifications to the rotating observatory building to accommodate the larger OSS

Project Summary



Completion Date
New Construction
Advanced Analysis
Science & Defense
Harvard-Smithsonian Astrophysical Observatory

Key team members

Frank Kan
Frank Kan