The National Reconnaissance Office just revealed the existence of its "JUMPSEAT" line of spy satellites, eight of which launched to Earth orbit between 1971 and 1987.

US government declassifies Cold War-era 'JUMPSEAT' spy satellites

Source: space
Source Link: https://www.space.com/space-exploration/launches-spacecraft/nro-declassifies-cold-war-era-jumpseat-spy-satellite