Options for a new Arizona observatory - Configurations, costs and site

The process of creating a major observatory, with emphasis on the configurations, costs, and site involved, is examined. The premise that cost optimization starts with a modestly priced building block, such as a 7.5-m telescope, is considered. The telescope unit and the configurations in which it is used, ranging from a single telescope or a set of separate telescopes, to an MMT in which the light of all of the telescopes can be phased when desired, are described. It is shown that options exist for using elements in a nonredundant linear array or Michelson interferometer. A means of estimating costs of different facilities, all on the same basis, is provided. The importance of placing the observatory on a site, such as Mt. Graham in Arizona, which maximizes the output per unit cost of the facility is discussed.