NASA’s Nimbus meteorological research and development program tested advanced Earth-observation instruments aboard seven satellites launched from 1964 through 1978. Stabilized, Earth-pointing spacecraft in near-polar orbits supported visible, infrared, ultraviolet and microwave measurements of weather, atmospheric structure, ozone, oceans and other Earth-system properties. The series demonstrated techniques later used by operational and research satellites and helped establish long environmental records. Recovery of its original magnetic tapes and photographic film has extended access to historical observations for modern climate studies.