The Early Weather Satellite was a series of satellites launched in the 1960s to observe Earth's weather patterns. The first two satellites in the series were TIROS (Television Infrared Observation Satellite) and ESSA (Environmental Science Services Administration). TIROS was launched in April 1960 and was the first successful satellite to provide meteorological data from space. ESSA was launched in 1966 and provided more detailed data than TIROS. Both satellites revolutionized weather forecasting and climate research.