• The primary objective of the program was to provide the Environmental Science Services Administration with the capability of observing the Earth's cloud cover and weather patterns from space. This data would then be used by the US Weather Bureau to prepare operational weather analyses and forecasts, and by local users via APT Direct Readout ground stations for private research and
  forecasting. ESSA I, III, V, VII, and IX supplied over 275,000 pictures to the operational meteorological community, while ESSA II, IV, VI, and VIII supplied data to nearly 400 APT ground stations worldwide.
  
  

I	II	III	IV	V	VI
VII	VIII	IX