Consists of correspondence, memoranda, reports, proposals, publications, and related materials documenting the administration and scientific programs of the Smithsonian Astrophysical Observatory (SAO) primarily under Irwin Shapiro, Director (1983- ). A small amount of records were created by Shapiro's predecessor, George B. Field, Director (1973-1982). The records document the administration of SAO's scientific divisions and administrative departments; SAO scientific projects including the Infrared-Optical Telescope Array, the Multiple Mirror Telescope, and the Submillimeter Telescope Array; SAO relations with the Smithsonian Institution; SAO computer facilities; budgets; and SAO's role as a component of the Center for Astrophysics.