The US reconnaissance satellite program that operated from 1960 to 1972 was CORONA. It was the United States’ first successful photographic spy-satellite program and gathered intelligence by photographing areas of the Soviet Union, China, and other countries from orbit.
CORONA satellites used film-return capsules rather than sending ordinary digital images by radio. After photographing targets, a capsule reentered the atmosphere and was caught in midair by an aircraft using a parachute. The film was then developed and analyzed by US intelligence agencies.
The program began with the first successful recovery in August 1960 and continued through 1972. Its images helped American analysts assess missile sites, airfields, submarine bases, and other military installations at a time when direct overflight was politically dangerous.
CORONA was a program name, not the name of one satellite model. Its satellites were officially designated Discoverer for much of the public-facing effort, while the classified reconnaissance mission used the CORONA name. SAMOS, GAMBIT, and HEXAGON were separate reconnaissance programs or satellite families.