This NASA Chronology provides a diary of significant events in astronautics and aeronautics in the year 1975. Initiated in 1961 with a compendium of events from 1915-1960, this series is designed to serve as a reference for policymakers, reference librarians, and researchers. Each entry is followed by one or more citations of sources to which users may turn for further information on the particular event or development being chronicled. The Astronautics and Aeronautics series is one way in which the NASA History Office has attempted to implement its charter to disseminate information about the activities of the National Aeronautics and Space Administration, and to provide support for historians and other researchers in the area of United States aeronautical and space programs.