HEXAGON: Mapping Camera HEXAGON KH-9 reconnaissance satellites carried mapping cameras like this one on several missions. The Defense Mapping Agency used images from these cameras for war planning. These cameras improved mapping and charting accuracy with precise measurement data. To accurately measure sizes of objects and distances on the ground, HEXAGON had to record its precise position and altitude when ground pictures were made. To do this, the mapping camera module looked not only at the terrain below, but at the stars on the horizon to HEXAGON's left and right. The cone-shaped film return vehicle was very similar to those used in the CORONA program, modified to accept new film sizes. TECHNIAL NOTES: Terrain Camera: Itek, 12-in. focal length f/6.0, 9.5 in. film Stellar Cameras: Itek, two 10-in. focal length f/2.0, 70mm film Click here to return to Cold War in Space: Top Secret Reconnaissance Satellites Revealed. Find Out More Related Fact Sheets HEXAGON: KH-9 Reconnaissance Satellite Note: The appearance of hyperlinks does not constitute endorsement by the National Museum of the USAF, the U.S. Air Force, or the Department of Defense, of the external website, or the information, products or services contained therein.