The first in the NOAA series of operational polar orbiting satellites was launched in December 1970.

NOAA-1 through -5 satellites were the first to provide reliable global operational imaging in the visible and infrared. NOAA-1 carried television sensors and a dual-channel radiometer to provide images in the visible and infrared. NOAA-2 through -5 added two-channel scanning radiometers for high-resolution 0.9-km visible and infrared imaging. In 1972, operational temperature sounding was made possible for the first time by employing eight narrow channels in the 15-µm CO₂ portion of the infrared spectrum on NOAA-2.