Development of the Thirty-Meter Telescope Project

The Thirty-Meter Telescope (TMT) project is a welladvanced effort to construct one of the first of the next generation of extremely large telescopes with primary mirror diameter larger than 25 m. When used with an adaptive optics systems capable of producing diffraction- limited images, the science reach of a 30 m telescope is extraordinary with improvements in sensitivity over existing telescopes by as much as a factor of 80 for some kinds of observations. The TMT design extends that of the twin Keck 10 m telescopes now in operation and uses the same close-packed segmented primary mirror. The partnership that will finish the design, construct and operate the telescope is described.