For all the Pentagon's crowing about its success in hitting a defunct spy satellite with a missile last week, it's had very little to say about the satellite itself. But then, those Defence Department types aren't in the habit of giving away details about classified projects.
One thing we do know is that the satellite was flying under the auspices of the US government's National Reconnaissance Office. As it turns out, the NRO has been overseeing spy satellites for a half-century now. Its early efforts were declassified in the mid-1990s, and the grainy picture you see on this page is what the NRO describes as the "first imagery" taken by its once highly secret Corona satellite; it shows the Mys Shmidta Air Field in the Soviet Union on 18 August 1960.
Caption text by News.com's Jonathan Skillings.
Credit: National Reconnaissance Office
This photo, of the Soviet Union's Dolon Air Field in August 1966, shows more detail, including the location of heavy bombers -- a very important piece of information at the height of the Cold War.
When President Eisenhower approved the program in 1958, and throughout its 12-year run, information on military and aerospace efforts in the Soviet Bloc was very hard to come by, and the satellite's eye in the sky helped the US to peek behind the (iron) curtain. Corona, actually the name of a series of satellites used in the program, was a joint effort of the Defence Department and the Central Intelligence Agency.
According to the NRO Web site, the resolution of Corona's images was about two metres at its sharpest, 170 metres at its worst. Individual satellite images covered an area of about 16 kilometres by 193 kilometres.
Credit: National Reconnaissance Office
Detail is lacking in this look at a Chinese nuclear test site, four days after an explosion there, but the bleakness of the undated black-and-white image only serves to underscore the "Ground Zero" label.
Credit: National Reconnaissance Office
Here's an instantly recognisable landmark: the Pentagon, on a September day in 1967. Remember: this was long before the advent of Google Earth. The NRO calls Corona the "first operational space photo reconnaissance satellite".
Credit: National Reconnaissance Office
This graphic gives an overview of a Corona, with details on some of the systems. The tubular satellite -- an Agena spacecraft sent aloft by a Thor booster rocket -- included a pair of panorama cameras and something called a stellar-terrain camera. According to the NRO, the system took pictures while rotating, and the film -- yes, film -- had to be loaded into recovery vehicles for a return trip to Earth before anyone could see the orbital snapshots.
Credit: National Reconnaissance Office
In orbit, the satellite's distance from Earth ranged from about 185 to 275 kilometres. Missions lasted about 19 days, according to the NRO.
Credit: National Reconnaissance Office
Here's a closer look at one of the Corona's camera systems.
Credit: National Reconnaissance Office
When the capsules with the cameras came back down from space, they got picked up -- in midair over the Pacific Ocean, floating down while suspended from parachutes -- by planes such as this US Air Force C-119.
Credit: National Reconnaissance Office
The dark swaths in this map represent four days of coverage during an undated mission.
Credit: National Reconnaissance Office
The Corona satellite program captured its last images in 1972. Through 145 launches over the 12 years of service, the project recorded more than 800,000 satellite images. This one, from November 1970, shows logging and gold dredging activities in Siberia.
Coincidentally or not, the Landsat scientific satellite-imaging program, run by NASA and the US Geological Survey, began in 1972.
Credit: National Reconnaissance Office
The Corona images weren't always of military sites -- at least not current ones. This 1971 picture shows the ruins of a Roman fort at Lejjun, Jordan.
Credit: National Reconnaissance Office
Visit reviews.cnet.co.uk for in-depth reviews of many more products
