The Corona program was a top-secret U.S. satellite reconnaissance initiative managed by the CIA during the Cold War. Its goal was to gather intelligence on the Soviet Union and China by capturing high-resolution photographs from orbit. These images were stored on silver film, which was retrieved mid-air by specially equipped aircraft. The program was kept secret for over 30 years, until 1995, when President Bill Clinton signed an executive order to declassify more than 860,000 images taken between 1960 and 1972. These records are now preserved at the U.S. National Archives and the EROS center of the U.S. Geological Survey. The Corona program began in 1958, during the height of the Cold War, when the United States feared a strategic disadvantage against the Soviet Union. This concern, known as the "missile gap," suggested that the USSR might have a larger arsenal of ballistic missiles. To gather intelligence without relying on traditional methods, the U.S. developed Corona, which was publicly presented as the Discoverer project—a scientific and technological initiative. In reality, the Discoverer name was a cover for the much more sensitive and classified Corona operation, which was managed by the CIA behind the scenes. The satellites launched as part of Corona were not scientific instruments but advanced photographic reconnaissance tools. They carried film capable of capturing detailed images of Soviet and Chinese territory, which was otherwise inaccessible to American intelligence. Because digital technology did not exist at the time, transmitting images via radio waves was not an option. Instead, the satellites released film capsules that descended toward Earth with parachutes. These capsules were intercepted mid-air by specially modified aircraft, a high-stakes maneuver that helped maintain the program’s secrecy. This method allowed the retrieval of vast amounts of visual intelligence without drawing attention to the true nature of the mission. Between 1959 and 1972, the Corona program launched 145 satellites across eight different series, with the last launch occurring on May 25, 1972. Maintaining such a long-lasting secret was remarkable, especially considering how much space activity is now monitored by amateur astronomers and other agencies. The declassification of Corona images in 1995 revealed an extensive collection of Earth observations from nearly twelve years, offering an unprecedented glimpse into Cold War-era intelligence gathering. The program’s legacy continues today, as the term "Key Hole" (KH) was derived from Corona and is used to classify American reconnaissance satellites. The program’s archives remain a valuable resource for historians and scientists, highlighting the complex relationship between scientific research and strategic interests during periods of geopolitical tension.