'On the occasion of this conference, the CIA History Staff is publishing this collection of newly declassified documents and imagery from the CORONA program'
https://www.cia.gov/library/center-for-the-study-of-intelligence/csi-publications/books-and-monographs/corona.pdf
En:
'Twenty years ago this month, the world learned about the existence of the first imaging reconnaissance satellite, codenamed CORONA.
It’s hard to imagine a world without Google maps or satellite imagery, but when CORONA was developed in the 1950s, satellite photo-reconnaissance didn’t exist.
CORONA was created by a small group of CIA, Air Force and private industry experts who were tasked with finding a way to provide broad imagery coverage of the USSR to identify missile launch sites and production facilities.
President Dwight D. Eisenhower formally endorsed CORONA in February 1958.
Known to the public as the U.S. Air Force’s Discoverer program, the classified CORONA project operated during the height of the Cold War to collect pictures over the denied areas of eastern Europe and Asia.
CORONA also had sister programs: ARGON for mapping imagery and LANYARD, a short-lived program designed for higher-quality imagery.
During its operational life, CORONA collected over 800,000 images in response to the national security requirements of the time. On average, individual images covered a geographic area on the Earth's surface of approximately 10x120 miles.
On February 24, 1995, Vice President Gore visited CIA Headquarters to announce Executive Order 12951, signed by President Clinton, which released CORONA, ARGON, and LANYARD imagery to the public.'
https://www.cia.gov/news-information/featured-story-archive/2015-featured-story-archive/corona-declassified.html