The quadrennium 1975–1978 was a period of great advance for solar‐wind studies, a period that combined exploration of new regions with increased maturity in established fields of study. The Helios, Pioneer, and Voyager spacecraft have been exploring the inner and outer regions of the solar wind. There has been a rebirth of the study of possible relations between solar variability and Earth's climate and weather, stimulated largely by Eddy's [1976] investigation of the Maunder Minimum; the solar wind may well prove to be a significant link in solar‐terrestrial relations. Unique coronal data from the SKYLAB 1973–1974 mission, in combination with satellite and ground‐based observations, provided the basis for identification of coronal holes as the main source of high‐speed solar wind.