Hexagon Signage

 

 

 

 

 

 

 

 

 

 

 

Information about the project and the satellite. For ease of reading and posterity here is what it says:

HEXAGON KH-9 reconnaissance satellites were the largest and last U.S. intelligence satellites to return photographic film to earth. During the Cold War, 19 HEXAGON missions imaged 877 million square miles of the Earth’s surface between 1971-1986.

HEXAGON’s main purpose was wide-area search. Analysts pored over HEXAGON’s photos of large areas, then focused in on potential threats with close-up surveillance from GAMBIT satellites.

The Lockheed Corp. built the HEXAGON vehicle. Its development included creating a very complex camera and film system. The satellite featured two separate cameras, designated KH-9 and made by the Perkin-Elmer Corp., working together to produce stereo images. These so-called “optical bar cameras” on the bottom of the satellite spun on their axes, taking overlapping images to form a very large panoramic picture. Objects smaller than two feet across could be imaged from around 80-100 miles altitude.

Some missions included a separate mapping camera mounted at the front of the satellite. This camera imaged wider areas to make very accurate maps for war planning and featured its own bucket-like film return vehicle.

The U.S. Air Force launched HEXAGON satellites aboard Titan IIID rockets from Vandenberg AFB, California, and provided tracking and control at an Air Force facility at Sunnyvale, Calif. USAF aircraft recovered film return vehicles in midair near Hawaii.

This artifact is on loan from the National Reconnaissance Office (Center for the Study of National Reconnaissance).

TECHNICAL NOTES:
Altitude: 80-370 nautical miles
Mission duration: 124 days average
Panoramic cameras: Perkin-Elmer, 60-inch focal length f/3.0, aperture 20 inches
Mapping camera: Itek, 12-inch focal length f/6.0, 9.5 in film, with two Itek 10-in focal length f/2.0, 70mm film cameras for star-tracking position reference
Film: length 320,000 feet (about 60 miles), width 6.6 inches
Film return vehicles: Four (five if mapping camera used)