schwit1 writes "The Big Bird, formally known as the KH-9 Hexagon satellite, was first placed in orbit in 1971 after its development by the National Reconnaissance Office (NRO), making it one of the most advanced spy satellites of its time. It is believed to have produced images of the Soviet Union, China and other countries that held strategic importance for the U.S. government through the Cold War. But it was never seen outside the intelligence community. This weekend, it will be available for all in the Washington area to see, but only for one day. To celebrate its 50-year anniversary, the NRO, along with the Smithsonian Institution, is for the first time publicly displaying the newly declassified relic at the Steven F. Udvar-Hazy Center in Chantilly, Va. In doing so, the intelligence agency is prompting more than just a little bit of excitement among reconnaissance experts and technical hobbyists."